Motor unit for an electric bike

Abstract

The application relates to a method for evaluating vertical and horizontal strain gauges within a load cell designed to measure external forces on a motor unit's spindle. It involves independently measuring vertical and horizontal strain signals, enabling the detection of discrepancies within a predefined tolerance. The approach ensures precise assessment of multi-directional forces, enhancing reliability and accuracy in force measurement.

Description

[0001] MOTOR UNIT FOR AN ELECTRIC BIKE

[0002] The present application generally relates to a motor unit for an electric bicycle, incorporating multi-directional force measurement, signal processing enhancements, error detection mechanisms, stop condition monitoring, torque control adjustments, antirollback functionality, and an optimized motor housing design.

[0003] Reference is made to the earlier patent applications DE102024111437.1 of 24 April 2024, EP25162430.0 of 08 March 2025, EP25162431.8 of 08 March 2025, EP25163742.7 of 14 March 2025, EP25163371.5 of 13 March 2025, EP25164599.0 of 19 March 2025, EP25165501.5 of 24 March 2025, EP25166345.6 of 26 March 2025, EP25166869.5 of 28 March 2025, EP25167880.1 of 02 April 2025, EP25167881.9 of 02 April 2025, EP25171848.2 of 23 April 2025, EP25172104.9 of 24 April 2025, EP25172105.6 of 24 April 2025, EP25172107.2 of 24 April 2025, EP25172108.0 of 24 April 2025, EP25172113.0 of 24 April 2025, EP25172111.4 of 24 April 2025, EP25172114.8 of 24 April 2025, EP25172115.5 of 24 April 2025, EP25172116.3 of 24 April 2025, EP25172117.1 of 24 April 2025, EP25172119.7 of 24 April 2025, EP25172121.3 of 24 April 2025, EP25172122.1 of 24 April 2025, EP25172124.7 of 24 April 2025, EP25172128.8 of 24 April 2025, EP25172146.0 of 24 April 2025, EP25172130.4 of 24 April 2025, EP25172131.2 of 24 April 2025, EP25172134.6 of 24 April 2025, EP25172136.1 of 24 April 2025, EP25172139.5 of 24 April 2025, EP25172169.2 of 24 April 2025, EP25172188.2 of 24 April 2025, EP25172144.5 of 24 April 2025, EP25172242.7 of 24 April 2025, EP25172157.7 of 24 April 2025, EP25172162.7 of 24 April 2025, EP25172165.0 of 24 April 2025, EP25172182.5 of 24 April 2025, EP25172176.7 of 24 April 2025, EP25172199.9 of 24 April 2025, EP25172203.9 of 24 April 2025, EP25172208.8 of 24 April 2025, EP25172213.8 of 24 April 2025, EP25172263.3 of 24 April 2025, EP25172219.5 of 24 April 2025, EP25172228.6 of 24 April 2025, EP25172233.6 of 24 April 2025, EP25172236.9 of 24 April 2025, EP25172239.3 of 24 April 2025, EP25172245.0 of 24 April 2025, EP25172247.6 of 24 April 2025, EP25172252.6 of 24 April 2025, EP25172255.9 of 24 April 2025, EP25172257.5 of 24 April 2025, and EP25172186.6 of 24 April 2025, the priorities of which are herewith claimed, and the contents of which are herein incorporated by reference. The application further relates to a control architecture associated with the electric bicycle or, more generally, with an electromechanical apparatus.

[0004] Additional aspects include signal substitution in case of sensor failure, angle correction for arbitrary mounting positions, distortion signal calculation, signal filtering, detection of stop intent, and Bluetooth-based communication with external devices. Further features relate to third-party communication interfaces, state machine architectures, modular system design, gearwheel and freewheel configurations, sensor device integration, SKEDD plug connections, thermal management components, and rider-state dependent control functions such as seat angle adjustment and acceleration sensing.

[0005] US 20130247657 A1 discloses a multi-component force measurement spindle unit that accurately measures forces and moments applied to a tire in a tire testing machine. The multi-component force measurement spindle unit of a tire testing machine includes: a spindle shaft on which a tire can be mounted, an inner sleeve that rotatably supports the spindle shaft via a bearing part, an outer sleeve arranged on an outside of the inner sleeve along an axial center direction of the spindle shaft, a multi-component force measurement sensor that connects an end of the inner sleeve and an end of the outer sleeve to each other and is capable of measuring a load acting on the outer sleeve from the inner sleeve, and a cooling part that cools the inner sleeve.

[0006] Generally, the object of the application is to provide an improved motor unit for an electric bike.

[0007] In particular, in light of the cited prior art, the object of the application is to provide a method of accurately evaluating the strain gauges of a load cell used to measure external forces applied to a spindle of a motor unit.

[0008] The object of the application is solved by the features of the independent claims.

[0009] Advantageous embodiments of the application are described in the dependent claims. In a first aspect, the application provides solutions for measuring vertical and horizontal strain gauges independently, comparing the measurement signals, and detecting errors within a predetermined range. This first aspect refers to a specific configuration or elements of aspects that relate to the measurement of forces in more than one direction, as described below.

[0010] In this context, a method is provided which can evaluate at least a vertical strain gauge and a horizontal strain gauge of a load cell being provided for measuring external forces applied on a spindle of a motor unit. One side of the spindle is preferably rotatably supported by a bearing in a bearing seat of a housing, wherein the strain gauges are preferably provided at the housing, in the vicinity of the bearing seat. A rotationally symmetric gearbox arrangement is preferably connected with the spindle. The gearbox arrangement preferably transmits torque from an electric motor to the spindle. Further, the vertical strain gauge and the horizontal strain gauge are preferably arranged nonparallel to each other.

[0011] The method may comprise the following steps. First, a vertical measurement signal of the vertical strain gauge may be measured. Independently, a horizontal measurement signal of the horizontal strain gauge may be measured. Additionally, a further vertical measurement signal of a further vertical strain gauge may be measured, the further vertical strain gauge being arranged parallel to the vertical strain gauge on the opposite side of a spindle of the motor unit. A combined vertical measurement signal may be determined as the difference between the further vertical strain gauge and the vertical strain gauge. Further, the method may comprise the step of applying a measure to compare the vertical measurement signal, the further vertical measurement signal, or the combined vertical measurement signal with the horizontal measurement signal. If the measure is inside a predetermined error range the method may detect an error. Another method step may be to apply a measure to compare the vertical measurement signal with the further vertical measurement signal and to detect an error if the measure is inside a predetermined error range.

[0012] This method is particularly suitable for use in an electric bicycle drive system. It enables real-time monitoring of the radial forces exerted on a spindle (or bottom bracket axle), allowing dynamic adjustment of motor power to provide optimal support for the cyclist. A load cell with strain gauges can be used for real-time monitoring. The method of evaluating the strain gauges described above leads to a number of advantages.

[0013] The method disclosed enables precise detection of misalignment or uneven loading on the spindle by comparing signals from strategically placed strain gauges, which enhances the reliability and accuracy of force measurements. The provision of both a vertical strain gauge and a horizontal strain gauge, arranged non-parallel to each other, enables the detection of multi-directional forces applied to the spindle. By measuring the vertical and horizontal measurement signals independently, the method allows for the isolation of strain effects due to different load directions, which facilitates more precise diagnostics and monitoring of the motor unit's operational conditions. The strain gauges are provided at the housing, in the vicinity of the bearing seat, making them easily accessible for measurement and analysis. The housing is mounted in the bearing seat. As the strain gauges are located close (in the vicinity) to the bearing seat, the strain gauges can directly and immediately measure a force applied to the spindle.

[0014] The term vicinity refers to the area around the bearing seat within the housing. Here, the strain gauges are preferably installed on the housing, in close proximity to the bearing seat, meaning they are positioned to directly and immediately measure forces applied to the spindle. For example, a strain gauge may have a radial distance of approximately 1 to 5 centimeters from the bearing seat, ensuring it is close enough to accurately capture the stresses induced by external forces on the spindle.

[0015] The strain gauges can be attached to a radially aligned / orientated wall of the housing and / or the load cell. Four strain gauges can be arranged concentrically and spaced at 90- degree intervals on the radially aligned / orientated wall. The radially aligned / orientated wall of the housing and / or load cell can be in connection to the bearing seat so that the force applied to the spindle is transmitted via the bearing seat to the radially oriented wall where the strain gauges are located.

[0016] A spindle can also be considered as the pedal shaft of a bottom bracket axle. Accordingly, it can be equipped with cranks or crank arms for mounting pedals. The terms vertical and horizontal are utilized to specify the orientation of components when observing the spindle from the front or end face. Vertical is defined as an orientation that aligns parallel to the gravitational axis, extending from the top to the bottom of the spindle. In contrast, horizontal describes an orientation that runs from side to side, directly perpendicular to the vertical. It should be noted that the terms "vertical" and "horizontal" are used to describe the typical, approximate orientation of the strain gauges. Accordingly, the vertical strain gauge can also be referred to a first strain gauge, the further vertical strain gauge to a second strain gauge, the horizontal strain gauge to a third strain gauge and the further horizontal strain gauge to a fourth strain gauge.

[0017] Due to their positioning, the strain gauges are specifically designed to detect external radial forces. These can be caused, for example, by the cyclist's pedaling or by the chain during the ride.

[0018] A rotationally symmetric gearbox arrangement may be a mechanical transmission system in which the arrangement of gears or other transmission elements exhibits rotational symmetry. This means that when the gear unit or any of its components are rotated around its main axis, they will return to their original position after completing a full circle. In this context, a rotationally symmetric gearbox may also be referred to as a rotational- cyclic gearbox. Essentially, this ensures that the gear setup remains consistent, displaying the same configuration as before the rotation. A cycle in this context refers to a complete rotation of the gear or transmission components around the main axis, after which all elements align in the same configuration as before. A gear unit with a rotationally symmetric structure can, for example, be designed as planetary gear systems, harmonic drive gear systems, harmonic pin drive gear system and / or cycloidal drive systems.

[0019] In further aspects that refer to elements of the measurement of forces in more than one direction, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below. A method is provided which can evaluate at least a vertical strain gauge and a horizontal strain gauge of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0020] One side of the spindle is preferably rotatably supported by a bearing in a bearing seat of a housing, wherein the strain gauges are preferably provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is preferably connected with the spindle, the gearbox arrangement preferably transmitting torque from an electric motor to the spindle, the vertical strain gauge and the horizontal strain gauge being arranged non-parallel to each other.

[0021] The method may comprise the following steps of measuring a vertical measurement signal of the vertical strain gauge, and of measuring a horizontal measurement signal of the horizontal strain gauge independently from the vertical strain gauge. The disclosed method enables the precise measurement of external forces applied to the spindle, which can enhance the accuracy of force detection and improve the overall performance of the motor unit. By measuring the vertical and horizontal strain gauge signals independently, the system can distinguish between different types of loads, such as rider-induced forces and chain forces, allowing for more sophisticated control strategies. The non-parallel arrangement of the strain gauges facilitates the decomposition of complex force patterns into their vertical and horizontal components, which can be critical for advanced diagnostics and maintenance of the motor unit.

[0022] Further, the vertical strain gauge and the horizontal strain gauge can be arranged perpendicular to each other. Arranging the vertical and horizontal strain gauges perpendicular to each other maximizes the independence of the measurement signals, which can significantly reduce cross-sensitivity and improve the reliability of the measurements. Alternatively, also a non-perpendicular angle would be possible, as long as it is not zero.

[0023] The method may further comprise the step of measuring a further vertical measurement signal of a further vertical strain gauge, the further vertical strain gauge being arranged parallel to the vertical strain gauge on an opposite side of a spindle of the motor unit. By using an additional vertical strain gauge on the opposite side of the spindle, the measurement results or the accuracy of the force measurement can be improved and be more reliable. The additional vertical strain gauge can also serve as a redundancy feature, ensuring that force measurements are still possible in the event of a single gauge failure, the accuracy of the force measurement by providing a balanced detection of strain

[0024] The method may further comprise the step of measuring a combined vertical measurement signal as a difference between a further vertical strain gauge and the vertical strain gauge, the further vertical strain gauge being arranged parallel to the vertical strain gauge on an opposite side of a spindle of the motor unit. Measuring a combined vertical measurement signal as a difference between two vertical strain gauges automatically compensates for perpendicular forces, which can lead to more accurate force measurements unaffected by lateral loads. This method inherently compensates for temperature influences that might otherwise distort the measurements. The differential measurement can reduce the impact of mechanical noise and vibrations on the signal, providing a cleaner and more stable output for control and analysis purposes.

[0025] The combined vertical measurement signal can be measured using a half bridge circuit. Utilizing a half bridge circuit for measuring the combined vertical measurement signal can improve the precision of the measurement. The half bridge circuit can increase the sensitivity of the measurement system, allowing for the detection of smaller changes in force, which can be important for fine-tuning the motor unit's response to rider input. Implementing a half bridge circuit can also reduce the electrical complexity of the system, potentially lowering production costs and simplifying maintenance without compromising measurement accuracy.

[0026] The method may comprise the step of measuring a further horizontal measurement signal of a further horizontal strain gauge, the further horizontal strain gauge being arranged parallel to the horizontal strain gauge on an opposite side of a spindle of the motor unit. The utilization of a further horizontal strain gauge on the opposite side of the spindle enhances the accuracy of the force measurement by providing a balanced detection of strain. By measuring a further horizontal measurement signal, the method can more effectively isolate and compensate for any non-torque-related deformations of the spindle.

[0027] The method may further comprise the step of measuring a combined horizontal measurement signal as a difference between a further horizontal strain gauge and the horizontal strain gauge, the further horizontal strain gauge being arranged parallel to the horizontal strain gauge on an opposite side of a spindle of the motor unit. The measurement of a combined horizontal measurement signal as a difference between two strain gauges allows for the automatic cancellation of errors, such as those induced by temperature fluctuations or external vibrations, leading to more accurate torque readings.

[0028] The combined horizontal measurement signal is measured using a half bridge circuit. The use of a half bridge circuit for measuring the combined horizontal measurement signal offers enhanced temperature compensation, as the circuit can be designed to automatically adjust for the resistance changes in the strain gauges due to temperature variations.

[0029] The strain gauges may be arranged with an angle difference of 90° to respective neighboring strain gauges. Arranging strain gauges at a 90° angle difference to neighboring gauges enables the method to distinguish between different types of forces, such as torque applied by the user and chain force, with greater clarity, which lead for accurate power output measurements. This angular arrangement facilitates the decomposition of complex force patterns into their respective components, allowing for more sophisticated analysis and control of the motor unit based on the precise nature of the forces involved. The strain gauges are located on a radially oriented / aligned wall of the housing and / or the load cell. This wall is perpendicular to the spindle axis.

[0030] The angle difference of 90° to respective neighboring strain gauges may refer to the arrangement of multiple strain gauges along a circle, where the angle between each neighboring strain gauge is 90°, measured relative to the central axis of the circle.

[0031] In this arrangement, the strain gauges may be positioned at four equidistant points around the circumference, forming a square pattern when viewed in a circular coordinate system. The strain gauges may be arranged at a side of a floating bearing of a spindle of the motor unit. Positioning strain gauges at the side of a floating bearing of the spindle ensures that the gauges are subjected to minimal mechanical interference from other components of the motor unit, leading to more stable and consistent strain measurements. This placement has been empirically determined to yield the best results in terms of torque measurement accuracy, as it allows the strain gauges to directly measure the deformation caused by the forces acting on the spindle without significant transmission losses or distortions.

[0032] The strain gauges may be arranged at a side of a sprocket wheel of a spindle of the motor unit. The arrangement of strain gauges at the side of the sprocket wheel enables direct measurement of the chain force, providing real-time data on the operational load experienced by the motor unit. This configuration facilitates the detection of uneven force distribution or excessive loads on the spindle, which can be critical for predictive maintenance and the prevention of mechanical failures.

[0033] One or some of the strain gauges can be arranged at a first side of the gearbox arrangement and one or some of the strain gauges are arranged at a second side of the gearbox arrangement. By positioning strain gauges on opposite sides of the gearbox arrangement, the system can accurately monitor torsional stresses and axial forces, enhancing the reliability of force measurements. The dual-sided gauge placement allows for the compensation of potential measurement errors due to misalignment or uneven force application, leading to more precise control and diagnostics of the gearbox's performance.

[0034] The vertical strain gauge can measure a driving force applied by a driver of an electric bicycle. The use of a vertical strain gauge to measure the driving force applied by the rider provides a direct correlation between rider input and motor assistance, enabling a more intuitive and responsive electric bicycle system. This measurement can be used to optimize the electric assist provided by the motor, ensuring efficient energy usage and prolonging the battery life of the electric bicycle. The horizontal strain gauge can measure a chain force of a chain of an electric bicycle. A horizontal strain gauge dedicated to measuring the chain force offers precise monitoring of the transmission system's efficiency, allowing for adjustments to be made to maintain optimal performance. The data collected by the horizontal strain gauge can be used to detect irregularities in chain tension or wear, which can be essential for maintaining the safety and longevity of the electric bicycle's drive system.

[0035] The method may further comprise the step of applying a measure to compare the vertical measurement signal, the further vertical measurement signal, or the combined vertical measurement signal with the horizontal measurement signal, the further horizontal measurement signal, or the combined horizontal measurement signal. The method may further comprise the step of detecting an error if the measure is inside a predetermined error range. The comparison of vertical and horizontal measurement signals enables the system to identify discrepancies that may indicate mechanical issues or calibration errors, thus enhancing the overall safety and reliability of the electric bicycle. Implementing a predetermined error range for the comparison measure allows for automated error detection, which can trigger maintenance alerts or system adjustments without the need for manual intervention, reducing downtime and improving user experience. For example, the strain gauges should measure corresponding signals, if not this indicates an error.

[0036] The method may further comprise the step of applying a measure to compare the vertical measurement signal with the further vertical measurement signal. The method may further comprise the step of detecting an error if the measure is inside a predetermined error range. The method enhances the reliability of the system by enabling the detection of discrepancies between expected and actual signal values, which may indicate potential malfunctions or calibration issues. By setting a predetermined error range, the method allows for a degree of tolerance, accommodating minor variations that do not impact system performance, thus avoiding unnecessary error detections. The comparison measure serves as a diagnostic tool that can facilitate maintenance and troubleshooting by pinpointing specific error conditions, leading to quicker resolution and reduced downtime. For example, the signals should be approximately similar, if not this indicates an error. The method may further comprise the step of applying a measure to compare the horizontal measurement signal with the further horizontal measurement signal. The method may further comprise the step of detecting an error if the measure is inside a predetermined error range. This method ensures the integrity of the horizontal alignment of the system by monitoring for deviations. For example, the signals should be approximately similar, if not this indicates an error.

[0037] The method may further comprise the step of detecting a local maximum or local minimum value in the vertical measurement signal, the further vertical measurement signal, or the combined vertical measurement signal. The method may further comprise the step of instantly holding a motor of the motor unit in response to detecting the maximum or minimum value. Instantly holding the motor in response to extreme values in the measurement signals can protect the system from potential damage caused by operating outside of its designed parameters. This feature can improve the precision of the motor unit's operations by ensuring that movements are halted at the precise moment an extreme value is detected.

[0038] The local maximum or local minimum value is preferably determined by taking a temporal derivative and detecting a zero crossing in the temporal derivative.

[0039] The local maximum or local minimum value is preferably determined by taking a derivative by an angular position of a spindle of the motor unit, and detecting a zero crossing in the derivative.

[0040] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, the gearbox arrangement transmitting torque from the electric motor to the spindle, the gearbox arrangement having a first side and a second side.

[0041] The motor unit also may comprise a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell.

[0042] The load cell may comprise at least a first strain gauge being a vertical strain gauge and / or a second strain gauge being a vertical strain gauge, and a third strain gauge being a horizontal strain gauge and / or a fourth strain gauge being a horizontal strain gauge. The load cell can be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0043] The presence of a load cell with multiple strain gauges, including both vertical and horizontal orientations, enables precise measurement of the external force applied to the motor unit, which can be used to optimize the control strategy for the motor and improve the responsiveness of the system to user input. Locating at least one strain gauge at the housing near the bearing seat ensures that the force measurements are taken at a critical point of mechanical stress, which can lead to more accurate readings and improved durability of the system by allowing for better monitoring and prevention of overload conditions.

[0044] The motor unit may comprise a fixed bearing holding the spindle at the first side of the gearbox arrangement, a loose bearing holding the spindle at the second side of the gearbox arrangement being axially opposite to the first side with respect to the spindle, and / or a sprocket wheel being arranged on the spindle. The use of a fixed bearing on the first side of the gearbox arrangement provides a stable and secure anchor point for the spindle, which can improve the precision of the rotational movement and reduce mechanical play, leading to smoother operation and less wear on the components. Incorporating a loose bearing on the second side of the gearbox arrangement allows for axial movement of the spindle, accommodating thermal expansion and contraction as well as other tolerances, which can enhance the longevity of the bearings and the overall reliability of the unit. The addition of a sprocket wheel on the spindle enables the unit to interface with a chain drive or similar transmission system, expanding the potential applications of the motor unit and allowing for easy integration into a variety of mechanical setups.

[0045] The first side of the gearbox arrangement is preferably axially opposite to the second side with respect to an axial extension of the spindle.

[0046] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit is configured to perform a method described above.

[0047] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0048] The sprocket wheel may be arranged at the second side of the gearbox arrangement. The sprocket wheel may be arranged rotationally fixed on the spindle. Mounting a sprocket wheel rotationally fixed on the spindle ensures that the power transmitted by the electric motor is directly and efficiently conveyed to the transmission system, minimizing power loss and enhancing the overall performance of the motor unit.

[0049] The first strain gauge and the second strain gauge may be oriented in parallel to each other. Orienting the first and second strain gauges in parallel allows for the effective measurement of strain along a single axis, which can simplify the signal processing and improve the accuracy of strain measurements in that specific direction. The parallel arrangement of these strain gauges can also provide a means for cross-validation of data, where discrepancies between the readings of the two gauges can be used to detect potential errors or malfunctions. The third strain gauge and the fourth strain gauge may be oriented in parallel to each other. The parallel orientation of the third and fourth strain gauges, similar to the first and second, allows for consistent and accurate strain measurements along another axis, which can be particularly beneficial in applications where multi-axial load analysis is critical. This configuration can also enhance the sensitivity and resolution of the load cell for detecting strain in the specific direction aligned with the third and fourth gauges, leading to more precise control in applications that depend on fine-tuned mechanical adjustments.

[0050] The third strain gauge and the fourth strain gauge may be oriented perpendicular to the first strain gauge and the second strain gauge. By orienting the third and fourth strain gauges perpendicular to the first and second, the load cell is capable of simultaneously measuring forces in orthogonal directions. This orthogonal arrangement allows for the decoupling of force measurements along different axes.

[0051] The load cell may be arranged at the second side of the gearbox arrangement.

[0052] The control unit may be configured to perform the steps of measuring a vertical measurement signal of the vertical strain gauge, and of measuring a horizontal measurement signal of the horizontal strain gauge independently from the vertical strain gauge. By measuring vertical and horizontal measurement signals independently, the control unit can provide more accurate diagnostics of force in multiple dimensions, leading to improved performance and reliability of the unit. Independent measurement allows for the isolation of specific stressors on the unit, enabling targeted adjustments and calibrations to be made, which can extend the lifespan of the unit.

[0053] The control unit may be configured to perform the step of measuring a combined vertical measurement signal as a difference between a further vertical strain gauge and the vertical strain gauge, the further vertical strain gauge being arranged parallel to the vertical strain gauge on an opposite side of a spindle of the motor unit. Measuring a combined vertical measurement signal by calculating the difference between two vertical strain gauges compensates for external influences such as perpendicular forces and temperature variations, resulting in more accurate and stable readings. The arrangement of the strain gauges on opposite sides of the spindle allows for self-compensation of measurement errors, which can enhance the precision of the control unit's output and improve the overall functionality of the motor unit.

[0054] The motor unit may further comprise a half bridge circuit for measuring a combined vertical measurement signal as a difference between a further vertical strain gauge and the vertical strain gauge. The use of a half bridge circuit for measuring the combined vertical measurement signal ensures that perpendicular force components are automatically canceled out, which simplifies the signal processing and reduces the need for complex compensation algorithms.

[0055] The control unit may be configured to perform the step of measuring a combined horizontal measurement signal as a difference between a further horizontal strain gauge and the horizontal strain gauge, the further horizontal strain gauge being arranged parallel to the horizontal strain gauge on an opposite side of a spindle of the motor unit. The measurement of a combined horizontal measurement signal by taking the difference between two horizontal strain gauges automatically compensates for perpendicular forces and temperature influences, which can significantly improve the precision of force measurements. This configuration allows for real-time compensation for any thermal expansion or contraction of the spindle, ensuring that the horizontal force measurements remain consistent and accurate under varying operating conditions.

[0056] The motor unit may further comprise a half bridge circuit for measuring a combined horizontal measurement signal as a difference between a further horizontal strain gauge and the horizontal strain gauge. The incorporation of a half bridge circuit with a further horizontal strain gauge allows for precise differential measurement, which enhances the accuracy of the horizontal force detection by canceling out common-mode noise and variations.

[0057] The strain gauges may be arranged with an angle difference of 90° to respective neighboring strain gauges. Arranging strain gauges at 90° angles to each other enables the system to effectively distinguish between different types of loads, such as torque applied by the user and the force exerted by a chain, improving the reliability of the system in multifaceted force environments. This orthogonal arrangement of strain gauges allows for the simultaneous measurement of ferees in multiple directions, which can be used to calculate the resultant vector force and torque, providing comprehensive data for the analysis of mechanical stress on the system.

[0058] In further aspects that refer to elements of the substitution of measurement signals, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0059] In this respect, a method is provided which can evaluate at least a vertical strain gauge and a horizontal strain gauge of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0060] One side of the spindle is preferably rotatably supported by a bearing in a bearing seat of a housing, wherein the strain gauges are preferably provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is preferably connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle, the vertical strain gauge and the horizontal strain gauge being preferably arranged non-parallel to each other.

[0061] The method may comprise measuring at least a vertical measurement signal of the vertical strain gauge and a further vertical measurement signal of the further vertical strain gauge. It may also include measuring a horizontal measurement signal of the horizontal strain gauge and a further horizontal measurement signal of the further horizontal strain gauge. If one of these signals is not available, it may be substituted by another signal.

[0062] The disclosed method enhances the reliability of force measurement by utilizing multiple strain gauges, ensuring that external forces applied to the motor unit's spindle are accurately assessed even if one of the gauges fails or provides an erroneous reading. By arranging the vertical and horizontal strain gauges non-parallel to each other, the method allows for the detection and differentiation of multi-directional stresses, thereby providing a comprehensive analysis of the forces acting on the spindle. The substitution of unavailable signals with other signals maintains the continuity of force measurement, which can be important for applications requiring constant monitoring.

[0063] The unavailability of a strain gauge can be caused, for example by a malfunction of the measuring equipment or a broken electrical line.

[0064] A signal may be substituted by another signal of the same orientation. Substituting a signal with another of the same orientation preserves the integrity of the measurement along the specific axis, ensuring that the directional force data remains consistent and reliable. This approach simplifies the data processing algorithm, as it avoids the need for complex calculations that would be required if signals of different orientations were used as substitutes. The use of a signal of the same orientation as a substitute minimizes the potential for introducing errors into the force evaluation, which could arise from the different mechanical properties or calibration variances between differently oriented strain gauges. For example, this feature ensures that a vertical signal is substituted by another vertical signal, and / or that a horizontal signal is substituted by another horizontal signal.

[0065] The vertical measurement signal can be used as a substitute for the further vertical measurement signal in case the further vertical measurement signal is not available. Using a vertical measurement signal as a substitute for another vertical signal ensures that the vertical load information is preserved. This substitution method allows for a straightforward and efficient redundancy strategy, as it leverages the existing vertical strain gauge infrastructure without the need for additional sensors or complex hardware modifications. The ability to interchange vertical signals enhances the system's fault tolerance, providing a robust solution for maintaining operational accuracy in the event of sensor degradation or failure.

[0066] The further vertical measurement signal may be used as a substitute for the vertical measurement signal in case the vertical measurement signal is not available. The reciprocal substitution between vertical measurement signals ensures that the system can adapt to sensor malfunctions on-the-fly, maintaining operational precision without the need for immediate maintenance or downtime. By enabling the further vertical measurement signal to be used as a substitute, the method provides a built-in backup mechanism.

[0067] The horizontal measurement signal may be used as a substitute for the further horizontal measurement signal in case the further horizontal measurement signal is not available. Enhanced reliability of the measurement system is achieved by ensuring that a backup horizontal measurement signal is available, thereby maintaining operational accuracy even if the primary signal is compromised or lost. Continuity of data collection is preserved without interruption.

[0068] The further horizontal measurement signal can be used as a substitute for the horizontal measurement signal in case the horizontal measurement signal is not available. System redundancy is increased by providing an alternative horizontal measurement signal, which enhances the robustness of the measurement process against sensor failures or signal disruptions. Measurement accuracy is maintained by ensuring that a substitute signal is available to provide data continuity. Operational efficiency is improved as the system can automatically switch to the substitute signal, minimizing the need for maintenance or recalibration that would otherwise be required if a sensor became inoperative.

[0069] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a vertical strain gauge and a further vertical strain gauge and / or a horizontal strain gauge and a further horizontal strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0070] The control unit can be configured to perform the following steps of measuring at least a vertical measurement signal of the vertical strain gauge and a further vertical measurement signal of the further vertical strain gauge, and / or a horizontal measurement signal of the horizontal strain gauge and a further horizontal measurement signal of the further horizontal strain gauge, and in case one of the signals is not available, substituting this signal by another signal.

[0071] The load cell equipped with multiple strain gauges allows for comprehensive force measurement, which can be used to tune the motor's response to external forces, resulting in a more natural riding feel. The ability of the control unit to substitute unavailable signals with other signals ensures uninterrupted performance monitoring, thereby maintaining the reliability and safety of the motor unit. The strategic placement of the strain gauges near the bearing seat in the housing provides high measurement accuracy due to the direct correlation between the force applied and the deformation detected by the gauges.

[0072] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0073] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above. The inclusion of a memory unit enhances the operational intelligence of the system, allowing for the storage of operational parameters, user preferences, or control algorithms, which can improve the efficiency and adaptability of the system's performance. The memory unit enables the system to record historical data, facilitating predictive maintenance and fault diagnosis, thereby reducing downtime and extending the lifespan of the system. In addition, the advantages of the method itself, which is performed by the control unit, are described above.

[0074] In further aspects that refer to elements of the angle correction of measurement signals, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below. A method is provided which can evaluate at least a vertical strain gauge and a horizontal strain gauge of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0075] One side of the spindle is preferably rotatably supported by a bearing in a bearing seat of a housing, wherein the strain gauges are provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle, the vertical strain gauge and the horizontal strain gauge being arranged nonparallel to each other.

[0076] The method may comprise the following steps of measuring a vertical measurement signal of the vertical strain gauge and of measuring a horizontal measurement signal of the horizontal strain gauge independently from the vertical strain gauge. The method further may comprise the step of calculating one or more angle-corrected signals, wherein each angle-corrected signal is calculated based on one or more of the vertical measurement signal, a further measurement signal, a combined vertical measurement signal, the horizontal measurement signal, a further horizontal measurement signal, and / or a combined horizontal measurement signal.

[0077] The disclosed method enables the precise measurement of external forces applied to the spindle, enhancing the accuracy of force detection and improving the overall performance of the motor unit. By calculating angle-corrected signals, the system can compensate for any rotational positioning of the motor within the bicycle, allowing for greater design flexibility and optimization of cable routing. The non-parallel arrangement of the strain gauges facilitates the simultaneous measurement of both applied force and chain force, leading to improved control functionality and a more responsive cycling experience.

[0078] The method may further comprise an angle-corrected signal being calculated according to a rotation of the load cell by a predefined angle. Calculating an angle-corrected signal according to the rotation of the load cell ensures that force measurements are consistent and accurate regardless of the load cell's orientation, enhancing the precision of the system.

[0079] The method further may comprise an angle corrected vertical signal being calculated as the vertical signal phase shifted by a predetermined angle. The calculation of an angle corrected vertical signal phase shifted by a predetermined angle accounts provides a more stable and accurate assessment of the vertical forces.

[0080] The method may further comprise an angle corrected further vertical signal being calculated as the further vertical signal phase shifted by a predetermined angle. The calculation of an angle corrected further vertical signal enhances the accuracy of sensor data interpretation by compensating for non-standard mounting angles of the motor unit, leading to improved performance of the system.

[0081] The method may further comprise an angle corrected combined vertical signal being calculated as the combined vertical signal phase shifted by a predetermined angle. The phase shift correction facilitates the integration of the motor unit into bicycles with unconventional frame angles without compromising the signal quality or the system's performance.

[0082] The method may further comprise an angle corrected horizontal signal being calculated as the horizontal signal phase shifted by a predetermined angle. The phase shift adjustment allows the system to be adaptable to various frame designs, enhancing the compatibility of the motor unit with a broader range of bicycles.

[0083] The method further comprises an angle corrected further horizontal signal being calculated as the further horizontal signal phase shifted by a predetermined angle. The angle correction of the further horizontal signal allows for the compensation of any misalignment due to the motor unit's mounting angle, ensuring that the system's response to lateral forces remains accurate. This adaptability to the mounting angle increases the system's utility across different bicycle types and designs, making it a more flexible solution for electric bicycle manufacturers. The phase shift correction preserves the quality of the signal. An angle corrected combined horizontal signal may be calculated as the combined horizontal signal phase shifted by a predetermined angle. The phase shift correction of the combined horizontal signal accounts for the motor unit's installation angle, which can be important for the accurate interpretation of combined lateral forces and torques, enhancing the system's dynamic response. This feature allows the system to be tuned for bicycles with unique frame geometries, ensuring that the motor assistance is consistent with the rider's expectations.

[0084] The phase shifting can be performed based on an angle position of the motor unit relative to a bicycle frame in which the motor unit can be installed. The phase shifting based on the angle position of the motor unit relative to the bicycle frame ensures that the motor's operation is optimized for the bicycle's current orientation, which can lead to more efficient power delivery and improved performance.

[0085] The method may further comprise the following steps of applying a measure to compare the angle corrected vertical measurement signal, the angle corrected further vertical measurement signal, or the angle corrected combined vertical measurement signal with the angle corrected horizontal measurement signal, the angle corrected further horizontal measurement signal, or the angle corrected combined horizontal measurement signal, and of detecting an error if the measure is inside a predetermined error range. Comparing angle-corrected measurement signals allows for more accurate error detection. The ability to detect errors within a predetermined range provides a safeguard against system malfunctions.

[0086] The method further may comprise the following steps of applying a measure to compare the angle corrected vertical measurement signal with the angle corrected further vertical measurement signal, and of detecting an error if the measure is inside a predetermined error range. By comparing angle-corrected vertical measurement signals, the system can precisely identify discrepancies that may indicate a malfunction or suboptimal performance, leading to timely maintenance and reduced wear on the motor unit. The method may further comprise the following steps of applying a measure to compare the angle corrected horizontal measurement signal with the angle corrected further horizontal measurement signal, and of detecting an error if the measure is inside a predetermined error range. This method of error detection can contribute to a more stable and secure riding experience.

[0087] The method may further comprise the following steps of detecting a maximum or minimum value in the angle corrected vertical measurement signal, the angle corrected further vertical measurement signal, or the angle corrected combined vertical measurement signal, and of instantly holding a motor of the motor unit in response to detecting the maximum or minimum value. The instant holding response of the motor upon detecting these values can act as a protective mechanism.

[0088] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a vertical strain gauge and a further vertical strain gauge and / or a horizontal strain gauge and a further horizontal strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0089] The control unit can be configured to perform the following steps of measuring a vertical measurement signal of the vertical strain gauge, of measuring a horizontal measurement signal of the horizontal strain gauge independently from the vertical strain gauge, and of calculating one or more angle-corrected signals, wherein each angle-corrected signal is calculated based on one or more of the vertical measurement signal, a further measurement signal, a combined vertical measurement signal, the horizontal measurement signal, a further horizontal measurement signal, and / or a combined horizontal measurement signal. The inclusion of a load cell with multiple strain gauges allows for comprehensive measurement of external forces applied to the motor unit, enabling precise monitoring and control of the motor's response to these forces. The control unit's ability to calculate angle-corrected signals based on independent vertical and horizontal measurement signals ensures that the force measurements are accurate and in particular it allows to freely position the motor in the bicycle.

[0090] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0091] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above. The advantages of the method as such are already mentioned above.

[0092] In further aspects that refer to elements of the calculation of distortion signal and error detection based thereon, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0093] In this respect, a method is provided which can evaluate one or more strain gauges of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0094] One side of the spindle is preferably rotatably supported by a bearing in a bearing seat of a housing, wherein at least one strain gauge is preferably provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is preferably connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle.

[0095] The method may comprise measuring a raw measurement signal of the strain gauge. A floating mean value of the raw measurement signal may then be calculated. The floating mean value may be output as a filtered measurement signal. A difference between the filtered measurement signal and the raw measurement signal may be determined. This difference may be output as a distortion signal.

[0096] The method enhances the accuracy of force measurements by filtering out repetitive distortion signals, which are particularly prevalent in the gearbox arrangement, resulting in a more reliable assessment of the external forces applied to the spindle. By calculating a floating mean value, the method provides a stable reference signal that averages over a specific angular range of the spindle, thereby improving the consistency of the measurement signal for motor control applications. The output of the distortion signal as a separate entity allows for the identification and isolation of errors originating from the motor and / or gear, facilitating targeted maintenance and reducing the likelihood of unexpected equipment failure.

[0097] The purpose of the filter is to eliminate repetitive distortion signals, especially having a repetition of one revolution or a bit less, or of which the repetition is known. The filtered measurement signal is more suitable for controlling the electric motor. The distortion signals especially originate from the gearbox arrangement due to its shoring against the spindle. The result is a revolving force signal. The signal without the distortions is much better suitable for controlling a motor.

[0098] The floating mean value averages over a certain angular range of the spindle which may provide a dynamic baseline that adjusts as the spindle rotates.

[0099] While the filtered signal originates from a driver, the difference between the raw signal and the filtered signal typically originates from motor and / or gear.

[0100] Outputting does not necessarily mean that the signal is delivered to an external entity, an internal further processing could be enough.

[0101] The method may further comprise the following step of performing an error determination based on at least one distortion signal. The inclusion of an error determination step based on the distortion signal enables proactive detection of anomalies in the system. The error determination step adds an additional layer of diagnostic capability to the system, allowing for more nuanced control strategies and the potential for automated adjustments to maintain optimal operation. The distortion signal originates primarily from the gearbox arrangement and a deviation from an expected signal indicates an error. The distortion signal typically remains constant over a long time.

[0102] The error determination may be performed by detecting an error if a measure for a difference between a distortion signal at a certain point in time or time span to a distortion signal at a previous point in time or time span exceeds a threshold. Detecting errors by comparing distortion signals at different times enhances the sensitivity of the system to changes in the gearbox arrangement, allowing for the early identification of wear or damage. The use of a threshold for difference measures between distortion signals provides a quantifiable criterion for error detection, which can be adjusted for different operational conditions and tolerance levels. The method's ability to reveal errors through temporal differences in the distortion signal contributes to a more robust predictive maintenance regime.

[0103] The measure can be a difference. Implementing the measure as a difference area between two curves offers a visual and quantitative method for assessing the stability of the distortion signal over time, which can be particularly useful for complex diagnostic analyses. The use of a difference as the measure for error determination allows for straightforward implementation in signal processing algorithms, facilitating integration into existing control systems. The approach of calculating a difference to identify errors ensures that even subtle variations in the distortion signal can be detected, enhancing the overall reliability of the system.

[0104] The measure may be a difference function comparing a signal over a predefined first time span to another signal over a predefined second time span, wherein the first time span and the second time span are non-overlapping. By analyzing separate time spans, the system can better account for variations in operational conditions, such as changes in load or speed, which may affect the distortion signal, thereby enhancing the precision of error detection. The error determination may be performed by detecting an error if a measure for a difference between a distortion signal at a certain time span to a comparison signal stored in a memory exceeds a threshold. The method enhances the reliability of the motor unit by enabling the detection of errors through the comparison of distortion signals with prestored comparison signals, ensuring that deviations beyond normal operating parameters are promptly identified. By setting a threshold for the difference between the distortion signal and the comparison signal, the method provides a quantifiable and adjustable parameter for error detection, allowing for fine-tuning based on specific application requirements. The use of memory-stored comparison signals facilitates the rapid assessment of signal discrepancies, which can lead to quicker diagnostic and corrective actions, minimizing downtime and maintenance costs.

[0105] The comparison signal can be specific for a type of motor unit. Tailoring the comparison signal to the specific type of motor unit accounts for the unique operational characteristics of different motors, which improves the accuracy of error detection and enhances the overall performance of the system. By considering the particularities of each motor unit type, the method can contribute to extending the lifespan of the motor by preventing the escalation of undetected errors that could cause further damage.

[0106] The distortion signal can be corrected or scaled according to a currently applied motor torque before being further processed in error determination. Correcting or scaling the distortion signal based on the currently applied motor torque ensures that the error determination is not skewed by normal operational variations, leading to more accurate fault detection. The normalization of the distortion signal allows for a more consistent comparison with stored signals, which can improve the detection of anomalies that are indicative of potential issues within the motor unit.

[0107] The floating mean value may be calculated over less than one entire revolution of a spindle of the motor unit. Calculating a floating mean value over less than one entire revolution of the spindle allows for the detection of errors that may occur within a single operational cycle. This approach to calculating the mean value can lead to more accurate monitoring of the motor unit's performance. The floating mean value may be calculated over an angle section out of one entire revolution of a spindle of the motor unit, the angle section being calculated as 1 minus (1 divided by gear ratio), the gear ratio being a gear ratio of a gear of the gearbox arrangement. By calculating the floating mean value over an angle section determined by the gear ratio, the method aligns the error detection process with the typical behavior of the distortion signal, enhancing the precision of fault identification. This calculation method takes into account the mechanical characteristics of the gearbox arrangement, which can lead to a more accurate representation of the motor unit's health and performance. The gear ratio-based angle section for mean value calculation ensures that the monitoring process is synchronized with the mechanical cycle of the gearbox, potentially improving the detection of gear-related anomalies and facilitating more effective preventative maintenance.

[0108] The specific angle section over which the floating mean value is calculated can be also determined by the formula 1 - ( - - - ). This formula is used to define a fraction of the gear ratio spindle's full revolution, based on the gear ratio of a connected gear within the gearbox. In practical terms, if the gear ratio is, for example, 4:1 , the spindle makes one complete turn for every four turns of the driving gear. Using the formula 1 - (i) the angle section calculated would be 1 - 0.25 = 0.75. This means that the floating mean value is calculated over 75% of the spindle's rotation.

[0109] The raw measurement signal can be measured in discrete measurement values. The discretization of the raw measurement signal into discrete measurement values facilitates digital processing and analysis, allowing for the implementation of advanced signal processing algorithms that can improve the accuracy and reliability of the measurement. By measuring the signal in discrete values, the data can be efficiently stored and transmitted, reducing the required storage capacity and bandwidth for communication between components in a system.

[0110] The discrete measurement value may be measured after a predefined angle of rotation of the spindle of the motor unit. Measuring discrete measurement values after a predefined angle of rotation ensures that the data collected is synchronized with the mechanical position of the motor unit. This approach allows an evaluation of an angular dependency of the measurement signal.

[0111] The predefined angle of rotation can be at least 10°, or at most 12 °, or 11 , 25°. The predefined angle of rotation yields good results.

[0112] The raw measurement signal may be measured as a resistance signal of the respective strain gauge. Measuring the raw measurement signal as a resistance signal of the respective strain gauge allows for direct correlation between mechanical strain and electrical resistance, enabling precise monitoring of stress and load conditions on the motor unit. Resistance-based measurement signals are inherently robust and can be easily interfaced with standard electronic components, simplifying the design and reducing the cost of the measurement system.

[0113] The steps of calculating a floating mean value, outputting the filtered measurement signal, and / or calculation of a distortion signal can be performed after each measurement of a measurement value. Calculating a floating mean value and outputting the filtered measurement signal after each measurement ensures real-time signal processing, which is essential for dynamic applications where immediate feedback is required for control purposes. The continuous calculation of a distortion signal after each measurement value allows for the immediate detection of signal anomalies, facilitating prompt corrective actions and reducing the likelihood of damage or failure in the motor unit.

[0114] The steps of measuring, calculating a floating mean value, outputting the filtered measurement signal and / or calculating a distortion signal can be performed for a first strain gauge, a second strain gauge, a third strain gauge, and / or a fourth strain gauge. The ability to perform measurements on multiple strain gauges enhances the precision of the system by providing redundancy and the opportunity for cross-validation of data, which can lead to more accurate and reliable measurements. Utilizing a floating mean value in the calculation process helps to reduce the impact of transient noise and fluctuations, resulting in a more stable and consistent measurement signal. The flexibility to calculate and output a filtered measurement signal or a distortion signal for each strain gauge allows for a comprehensive analysis of the forces acting on the spindle, facilitating detailed diagnostics and system optimizations.

[0115] The steps of measuring, calculating a floating mean value, outputting the filtered measurement signal, and / or calculation of a distortion signal may be performed for several or each strain gauge of the motor unit. The comprehensive data collection from multiple strain gauges facilitates advanced analytics.

[0116] The method may further comprise the following steps of measuring an electromotive force of a motor of the motor unit, and of calculating an angular position of a spindle of the motor unit based on the electromotive force. The ability to measure the electromotive force of the motor provides a non-contact method for determining the angular position of the spindle, which can enhance the reliability and longevity of the system by reducing mechanical wear associated with physical position sensors. Calculating the angular position of the spindle based on electromotive force allows for precise control of the motor unit, which can improve the accuracy of the system in applications requiring fine positional adjustments. This method can potentially allow for real-time monitoring and feedback control of the motor's position, leading to improved performance in dynamic environments where the spindle position needs to be adjusted rapidly.

[0117] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a first and / or a second strain gauge or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0118] The control unit can be configured to perform the following steps of measuring a raw measurement signal of the strain gauge, of calculating a floating mean value of the raw measurement signal, of outputting the floating mean value as a filtered measurement signal, of calculating a difference between the filtered measurement signal and the raw measurement signal, and of outputting the difference as a distortion signal. The integration of a load cell with multiple strain gauges enables accurate measurement of external forces applied to the motor unit, which is critical for systems that require force feedback or load monitoring for safety and efficiency. The control unit's ability to filter the raw measurement signal and output a distortion signal allows for enhanced signal processing, which can lead to more accurate force measurements by compensating for noise and other signal disturbances. Positioning at least one strain gauge at the housing near the bearing seat ensures that the force measurements are taken close to the point of application, which can improve the precision of the load cell readings.

[0119] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0120] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above. The inclusion of a memory unit allows for the storage of operational data, which can be used for later analysis, diagnostics, or optimization of the motor unit's performance. The memory unit enables the method to retain historical data, which can be instrumental in predictive maintenance and in identifying long-term trends or wear patterns in the motor unit's operation. In addition, the advantages of the method itself, which is performed by the control unit, are described above.

[0121] The control unit may be further configured to perform an error determination based on at least one distortion signal. The control unit's ability to perform error determination based on distortion signals enhances the reliability of the system by enabling early detection of anomalies that could indicate mechanical or structural issues within the gearbox arrangement. By automating the error determination process, the control unit reduces the need for manual inspections and maintenance checks, thereby decreasing downtime and operational costs associated with gearbox maintenance.

[0122] In further aspects that refer to elements of detecting a stop condition based on maximum or minimum value of signals, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0123] In this respect, a method is provided which can evaluate one or more strain gauges of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0124] One side of the spindle is rotatably supported by a bearing in a bearing seat of a housing, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle.

[0125] The method comprises the following steps of measuring a raw measurement signal of the strain gauge, of calculating a floating mean value of the raw measurement signal, of outputting the floating mean value as a filtered measurement signal, of detecting a maximum or minimum value in the first filtered measurement signal and / or the second filtered measurement signal, and of instantly holding the motor of the motor unit in response to detecting the maximum or minimum value.

[0126] The method enhances the accuracy of force measurement by filtering out repetitive distortion signals, leading to a more reliable control of the electric motor based on the actual forces applied by the user. By detecting sudden changes in force application, such as a stop in pedaling, and instantly holding the motor, the method improves the safety and responsiveness of the motor unit, providing a more intuitive user experience. The use of a floating mean value calculated over a certain angular range of the spindle allows for a dynamic adjustment to varying conditions, ensuring consistent performance of the motor unit under different operating scenarios. The holding the motor may be only performed if an angle of a crank to which a force is applied indicates a downwards orientation of the crank. Associating the holding of the motor with the crank's downward orientation ensures that the motor response is specifically tailored to the natural cycling behavior. This development improves the system's ability to discern intentional stops in pedaling from regular cycling variations, thereby enhancing the precision of motor assistance. The targeted response to a downward-oriented crank position allows for optimized energy usage, as the motor is held only when a true stop in pedaling is detected, avoiding unnecessary activation or deactivation.

[0127] The downward orientation may refer to the position of a bicycle crank where it points downwards, aligning with the direction of gravity. This orientation occurs when the pedal is at the lowest point of its cycle.

[0128] The method may further comprise the following step of controlling a driving force of the motor unit based on one or more filtered measurement signals. The driving force may assist the driver with driving the bicycle, the driving force is applied in addition to a muscular force applied on pedals. Utilizing filtered measurement signals that are devoid of distortion from the gearbox and motor allows for more precise control of the driving force, resulting in an improved riding experience for the user. By relying on cleaner signals for driving force control, the system can respond more accurately to the user's input, enhancing the efficiency and responsiveness of the motor assistance. The improved signal quality for driving force control can lead to better energy management within the motor unit, potentially extending the battery life and range of the bicycle.

[0129] The method may further comprise the following steps of detecting, after instantly holding the motor, if the spindle is driven further by the driver, and if the spindle is driven further by the driver, instantly re-activating the motor. The instant re-activation of the motor upon detecting further spindle movement by the driver ensures that any erroneous stop conditions are quickly corrected, minimizing disruptions to the rider's experience. This feature provides a safety mechanism that allows the motor to resume operation immediately if the rider continues to exert force, ensuring that the motor unit can support the rider effectively in all conditions. The ability to detect and correct errors in real-time significantly reduces the likelihood of noticeable distortions in motor assistance, which can be critical for maintaining rider confidence and control during operation.

[0130] Preferably, it can be detected if the spindle is driven further by monitoring an angle of the spindle. Monitoring the angle of the spindle to detect further driver-induced rotation provides a simple and effective method for determining whether the motor should be reactivated. This approach allows for a seamless transition between motor-assisted and manual pedaling modes.

[0131] Preferably, it can be detected if the spindle is driven further by monitoring a torque applied by the driver. The detection of further spindle rotation through torque monitoring ensures real-time feedback on the user's input, allowing for precise control and adjustment of the system's operation based on the user's activity. By monitoring the torque applied by the driver, the system can distinguish between intentional user interaction and passive movement, enhancing the accuracy of the control mechanism and improving user experience.

[0132] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a first and / or a second strain gauge or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0133] The control unit can be configured to perform the following steps of measuring a raw measurement signal of the strain gauge, of calculating a floating mean value of the raw measurement signal, of outputting the floating mean value as a filtered measurement signal, of detecting a maximum or minimum value in the first filtered measurement signal and / or the second filtered measurement signal, and of instantly holding the motor of the motor unit in response to detecting the maximum or minimum value.

[0134] The inclusion of a load cell with strain gauges near the bearing seat allows for accurate measurement of external forces applied to the motor unit, enabling precise control of the motor's response to user input. The control unit's ability to calculate a floating mean value of the raw measurement signal and detect maximum or minimum values ensures that the motor's response is based on a stable and reliable signal. Instantly holding the motor in response to detected maximum or minimum values can serve as a safety feature, preventing potential overloading or damage to the system due to excessive force application.

[0135] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0136] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above. The advantages of the method, which is performed by the control unit, are described above.

[0137] In further aspects that refer to elements of filtering of measurement signals, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0138] In this respect, a method is provided which can evaluate one or more strain gauges of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0139] One side of the spindle is rotatably supported by a bearing in a bearing seat of a housing, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle.

[0140] The method comprises the following steps of measuring a raw measurement signal of the strain gauge, calculating a floating mean value of the raw measurement signal, and outputting the floating mean value as a filtered measurement signal.

[0141] The method enhances the accuracy of force measurement by the strain gauge, as the floating mean value reduces the impact of repetitive distortion signals, leading to more precise control of the electric motor. By filtering out distortions, particularly those caused by the gearbox arrangement, the reliability of the load cell's output is improved, ensuring consistent performance over time. The outputted filtered measurement signal provides a cleaner data set for further processing, which is advantageous for advanced analytics and diagnostics of the motor unit's operation.

[0142] A control unit is provided. The control unit may be configured to perform a method described above. A control unit configured to perform the method as described in the preceding described above is capable of integrating complex strain gauge data processing, which allows for real-time monitoring and adjustment of the system based on precise force measurements. The control unit's design to execute these methods ensures compatibility with advanced sensor technologies and provides a scalable solution for various applications requiring detailed force analysis, such as in electric bicycles, exercise equipment, or industrial machinery.

[0143] A method for manufacturing a control unit is provided. The method can comprise the following steps of providing a control unit, and of loading software on a memory of the control unit, the software causing the control unit to perform a method described above. The method for manufacturing a control unit by loading specific software onto its memory ensures that the control unit is readily customizable for different applications, allowing manufacturers to efficiently tailor the control unit's functionality to meet diverse requirements. This approach to manufacturing enables rapid deployment of updates and enhancements to the control unit's capabilities, as improvements can be implemented through software changes without the need for hardware modifications, reducing time-to- market and facilitating ongoing product evolution.

[0144] Furthermore, a method for manufacturing a motor unit is provided. The method comprises the following steps. An electric motor, a control unit, a load cell and a memory unit may be provided. The electric motor may comprise a gearbox arrangement with a spindle for applying an external force to the motor unit. The load cell may comprise at least a first strain gauge and a second strain gauge, or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge, the load cell being provided for measuring an external force that is applied to the motor unit. The electric motor, the load cell, and the memory may be connected with the control unit. Alternatively, the electric motor, the load cell, and the memory unit are already connected with the control unit. Further, a computer software may be loaded into the memory unit, the computer software causing the control unit to perform a method described above or the memory unit already comprises a computer software causing the control unit to perform a method described above.

[0145] The integration of a load cell with multiple strain gauges enhances the precision of force measurement applied to the motor unit, leading to improved control and feedback for the user. The connection of the electric motor, load cell, and memory unit with the control unit allows for centralized management of the motor unit's functions. Loading computer software into the memory unit that enables the control unit to perform predefined methods ensures consistent and reliable operation of the motor unit.

[0146] A motor unit for an electric bicycle is provided which is manufactured as described above. The motor unit's design, tailored for electric bicycles, provides a compact and efficient integration of the electric motor with the gearbox arrangement, optimizing the space within the bicycle frame. The manufacturing process of the motor unit ensures that it is equipped with the necessary components and software to perform effectively in an electric bicycle, reducing the need for additional adjustments or calibrations post-installation. The method of manufacturing the motor unit includes steps that ensure the compatibility of hardware and software components, leading to a seamless user experience and enhanced performance of the electric bicycle. Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a first and / or a second strain gauge or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0147] The control unit can be configured to perform the following steps of measuring a raw measurement signal of the strain gauge, of calculating a floating mean value of the raw measurement signal, and of outputting the floating mean value as a filtered measurement signal.

[0148] The placement of the strain gauge at the housing near the bearing seat allows for accurate detection of external forces, which is crucial for the precise control of the motor unit's output. The control unit's ability to calculate a floating mean value of the raw measurement signal from the strain gauge results in a filtered measurement signal that is less susceptible to noise, enhancing the reliability of the force measurements. The configuration of the control unit to process and output a filtered measurement signal enables real-time adjustments to the motor unit's operation, leading to a more responsive and smoother riding experience for the user.

[0149] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the methods above apply analogously to the motor unit and the control unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit and control unit are transferable to the methods above.

[0150] The control unit may be configured to control a driving force of the motor unit based on one or more filtered measurement signals. The inclusion of a control unit that adjusts the motor unit's driving force based on filtered measurement signals enhances the precision of the motor's operation, as it relies on refined data that is less likely to be affected by noise or transient disturbances. This configuration can lead to improved performance and longevity of the motor unit by ensuring that the driving force is modulated in response to accurate and relevant operational parameters, thereby reducing unnecessary stress on the system.

[0151] The control unit may be configured to measure the raw measurement signal in discrete measurement values. By configuring the control unit to measure raw measurement signals in discrete values, the system can effectively process and analyze data, which facilitates the implementation of digital control algorithms and improves the overall controllability of the motor unit. Discrete measurement values allow for efficient storage and retrieval of measurement data, which can be used for system diagnostics, performance optimization, and predictive maintenance, thereby enhancing the reliability of the unit.

[0152] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above.

[0153] In further aspects that refer to elements of error detection based on strain gauge signals, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0154] In this respect, a method is provided which can evaluate at least two strain gauges of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0155] One side of the spindle is rotatably supported by a bearing in a bearing seat of a housing, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle. The method comprises the following steps of measuring a respective raw measurement signal of at least two strain gauges, of applying a measure to the raw measurement signals, or filtered measurement signals being calculated out of the raw measurement signals, of two or more strain gauges, the measure being indicative for a phase difference between a measurement signal of a first strain gauge or a second strain gauge to a measurement signal of a third strain gauge or a fourth strain gauge, and of detecting an error if the measure reveals a phase difference being outside of a tolerance band. The method enhances the reliability of the load cell by detecting phase differences in the signals from multiple strain gauges, which can indicate misalignment or malfunction within the system. By establishing a tolerance band for acceptable phase differences, the method provides a quantifiable standard for error detection, facilitating automated monitoring and maintenance scheduling. The use of raw measurement signals or filtered signals for phase difference analysis allows for flexibility in signal processing, which can be tailored to the specific requirements of the motor unit and its operational environment.

[0156] The tolerance band may comprise a value of 90°. With two strain gauges having an angle between their orientations of 90°, a phase difference of 90° is expected. A deviation from this indicates an error.

[0157] A method is provided which can evaluate at least a vertical strain gauge and a horizontal strain gauge of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0158] One side of the spindle is rotatably supported by a bearing in a bearing seat of a housing, wherein the strain gauges are provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle, the vertical strain gauge and the horizontal strain gauge being arranged non-parallel to each other.

[0159] The method comprises the following steps of measuring a respective raw measurement signal of at least two strain gauges, of applying a measure to the raw measurement signals or to filtered measurement signals being calculated out of the raw measurement signals of two strain gauges, the measure being indicative for a difference in signal form, and of detecting an error if the measure exceeds a predetermined threshold.

[0160] The method improves fault diagnosis by identifying discrepancies in signal form between strain gauges, which can be indicative of specific types of strain or stress anomalies. By setting a predetermined threshold for error detection, the method allows for customizable sensitivity settings that can be adjusted based on the precision requirements of the application. The ability to detect errors based on differences in signal form provides a nuanced approach to error detection, potentially identifying issues that may not be apparent through other means of analysis.

[0161] The method may further comprise the step of responsive to detecting an error, stopping the motor unit and / or issuing a warning to a user. Enhances the safety of the system by immediately halting the motor unit upon error detection, thereby preventing potential damage to the machinery or harm to the user. Increases the reliability of the system by providing real-time feedback to the user through warnings, allowing for prompt corrective action to be taken. Reduces downtime and maintenance costs by preventing the escalation of errors into more serious faults through immediate intervention.

[0162] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a first and / or a second strain gauge or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0163] The control unit can be configured to perform the following steps of measuring a raw measurement signal of the strain gauge, of applying a measure to the raw measurement signals or filtered measurement signals being calculated out of the raw measurement signals of two or more strain gauges, the measure being indicative for a phase difference between a measurement signal of the first strain gauge or the second strain gauge to a measurement signal of the third strain gauge or the fourth strain gauge, and of detecting an error if the measure reveals a phase difference being outside of a tolerance band.

[0164] Additionally or alternatively, the control unit can be configured to perform the following steps of measuring a respective raw measurement signal of at least two strain gauges, of applying a measure to the raw measurement signals or to filtered measurement signals being calculated out of the raw measurement signals of two strain gauges, the measure being indicative for a difference in signal form, and of detecting an error if the measure exceeds a predetermined threshold.

[0165] This provides precise measurement of external forces applied to the motor unit by utilizing a load cell with multiple strain gauges, leading to improved control and operational accuracy. Enhances fault detection capabilities by measuring phase differences or signal form discrepancies between strain gauges, allowing for early identification of potential issues. Improves the longevity and performance of the system by enabling the control unit to apply corrective measures based on the analysis of raw or filtered measurement signals from the strain gauges.

[0166] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0167] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above.

[0168] The control unit may be further configured to perform the following step of responsive to detecting an error, stopping the motor unit and / or issuing a warning to a user. The control unit's capability to stop the motor unit or issue a warning upon error detection significantly increases the safety of the system by preventing potential damage to the machinery or harm to the user. The proactive error response mechanism provided by the control unit minimizes downtime by allowing for immediate intervention, which can reduce the risk of cascading failures in interconnected systems. The automatic warning feature serves as an early detection system for maintenance needs, thereby facilitating preventative maintenance schedules and reducing the likelihood of unexpected breakdowns.

[0169] In further aspects that refer to elements of detecting stop condition based on signal comparison; various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0170] In this respect, a method is provided which can evaluate one or more strain gauges of a load cell being provided for measuring external forces applied on a spindle of a motor unit.

[0171] One side of the spindle is rotatably supported by a bearing in a bearing seat of a housing, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle, the gearbox arrangement transmitting torque from an electric motor to the spindle.

[0172] The method comprises the following steps of measuring a raw measurement signal of the strain gauge, of comparing a value of at least one of the measurement signals actually measured or calculated based on the measurement signal with a value of that measurement signal measured at a predefined previous angular position, and of instantly holding a motor of the motor unit in response to detecting that a different between the two compared values is larger than a threshold.

[0173] The method enhances the safety and reliability of the motor unit by instantly holding the motor upon detecting a discrepancy in strain gauge measurements, which may indicate an abnormal or unexpected load condition. By comparing measurement signals at predefined angular positions, the method provides a dynamic monitoring system that can detect subtle changes in load, potentially preventing damage to the motor unit or associated machinery. The real-time response to detected differences in strain gauge values allows for immediate corrective action, minimizing the risk of prolonged exposure to harmful operating conditions.

[0174] For optimal effectiveness, it is preferable for the motor stop to occur within less than 50 milliseconds to prevent inconvenience to the rider; 100 milliseconds would be too long. This method achieves an instantaneous stop.

[0175] The previous angular position may be calculated as an angular position at which the actually measured or calculated measurement signal was measured or calculated, minus a total revolution of the spindle, or minus an angular difference being calculated as 1 minus (1 divided by gear ratio), the gear ratio being a gear ratio of a gear of the motor unit. The method improves the precision of the monitoring system by accounting for the spindle's total revolutions. By incorporating the gear ratio into the calculation of the previous angular position, the method ensures accurate alignment of measurement signals with the mechanical configuration of the motor unit, enhancing the detection of anomalies. The method's ability to calculate the previous angular position based on gear ratio adjustments allows for adaptability to various gearbox configurations, making it versatile for different motor unit designs.

[0176] Furthermore, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a first and / or a second strain gauge or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0177] The control unit can be configured to perform the following steps of measuring a raw measurement signal of the strain gauge, of comparing a value of at least one of the measurement signals actually measured or calculated based on the measurement signal with a value of that measurement signal measured at a predefined previous angular position, and of instantly holding the motor of the motor unit in response to detecting that a different between the two compared values is larger than a threshold.

[0178] The integration of a load cell with multiple strain gauges into the housing near the bearing seat allows for direct measurement of external forces, which can enhance the accuracy of force feedback and improve the motor unit's response to load changes. The control unit's ability to instantly hold the motor upon detecting a significant difference in measured values provides a safety feature that can prevent damage to the motor unit or the system it is operating within, by rapidly responding to overload conditions.

[0179] The motor unit may further comprise a memory unit, the memory unit comprising software causing the control unit to perform a method described above and / or wherein the control unit may be configured to perform a method described above.

[0180] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0181] In further aspects that refer to elements of the mechanical features of the motor unit, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0182] In this respect, a motor unit for an electric bicycle is provided. The motor unit may comprise an electric motor with a gearbox arrangement with a spindle for applying an external force to the motor unit, a control unit, at least one bearing rotatably supporting the spindle in a bearing seat of a housing and a load cell. The gearbox arrangement may transmit torque from the electric motor to the spindle and the gearbox arrangement may have a first side and a second side. The load cell may comprise at least a first and / or a second strain gauge or a first strain gauge, a second strain gauge, a third strain gauge, and a fourth strain gauge. The load cell may be provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge is provided at the housing, in the vicinity of the bearing seat.

[0183] The integration of a load cell with strain gauges in close proximity to the bearing seat of the housing enables precise measurement of the external force applied by the rider, enhancing the control unit's ability to adjust motor assistance for improved riding dynamics. The arrangement of the gearbox transmitting torque directly to the spindle ensures efficient power transfer from the electric motor to the pedals, resulting in a more responsive and energy-efficient electric bicycle.

[0184] The presence of a fixed bearing on the first side and a loose bearing on the second side of the gearbox arrangement provides a robust support system for the spindle, ensuring stable and smooth pedal operation even under varying load conditions. The inclusion of a sprocket wheel on the spindle facilitates the direct transfer of pedaling force to the drivetrain, allowing for a more intuitive and natural cycling experience. The dual bearing configuration helps to accommodate thermal expansion and contraction of the spindle, maintaining optimal alignment and reducing wear on the motor unit components.

[0185] The motor unit may further comprise a sprocket wheel being arranged at the second side of the gearbox arrangement. Positioning the sprocket wheel at the second side of the gearbox arrangement simplifies the drivetrain layout, potentially reducing the overall weight and complexity of the electric bicycle. The arrangement of the sprocket wheel on the same side as the load cell allows for more direct and accurate measurement of the forces applied by the cyclist, leading to enhanced feedback and control for the motor assistance system. The proximity of the sprocket wheel to the gearbox may facilitate easier access for maintenance and adjustments, improving serviceability of the electric bicycle.

[0186] The motor unit may further comprise a load cell being arranged at the second side of the gearbox arrangement. This configuration may reduce the complexity of the force measurement system by minimizing the distance between the point of force application and the load cell, leading to a more compact and efficient design. The strategic location of the load cell can also protect it from environmental factors and mechanical interference, potentially increasing its accuracy and longevity.

[0187] The motor unit may further comprise a sprocket wheel being arranged rotationally fixed on the spindle. The rotational fixation of the sprocket wheel on the spindle eliminates the need for a freewheel mechanism, which can lead to more immediate power transfer and a more engaged cycling experience, particularly beneficial for competitive racing applications. Omitting the freewheel reduces the number of moving parts, which can decrease mechanical losses, enhance the reliability of the motor unit, and lower the maintenance requirements. The direct connection between the sprocket wheel and the spindle ensures that the cyclist's energy is efficiently converted into forward motion, which is crucial for achieving optimal performance in race conditions.

[0188] The motor unit may have one single freewheel, the freewheel being arranged between a gear of the gearbox arrangement and the spindle. The inclusion of a single freewheel between a gear of the gearbox arrangement and the spindle allows for the decoupling of the motor unit from the spindle when the motor is not powered, thereby reducing drag and improving energy efficiency during passive operations. This configuration can also protect the motor unit from potential damage caused by back-driving forces, as the freewheel mechanism permits the spindle to rotate independently of the gearbox under certain conditions, enhancing the durability of the system. The integration of a single freewheel between the gearbox gear and the spindle results in a more compact and lightweight design, enhancing the overall efficiency and portability of the unit. The elimination of a second freewheel simplifies the mechanical structure, potentially reducing manufacturing costs and maintenance requirements.

[0189] The load cell may comprise a first strain gauge, a second strain gauge, a third strain gauge, and / or a fourth strain gauge. The incorporation of multiple strain gauges within the load cell enables the unit to accurately measure multi-directional forces, providing comprehensive data for precise control and monitoring of mechanical loads. The redundancy offered by having a first, second, third, and / or fourth strain gauge ensures reliability in the load cell's measurements, as the failure of a single gauge can be compensated by the remaining operational gauges, thus maintaining the integrity of the load monitoring.

[0190] In further aspects that refer to elements of the anti-rollback mode, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0191] A method of providing an anti-rollback mode for an electric bicycle is provided. The electric bicycle has a motor unit with a motor comprising a stator at least one stator coil and a control unit having at least two driver circuits each with a low-side switch and a high-side switch. At least one stator coil is connected with two driver circuits, such that the stator coil can be supplied with power by one of the driver circuits and connected with ground by the other driver circuit.

[0192] The method may comprise the step of while the anti-role-back mode is activated, connecting both ends of the stator coil with a common voltage.

[0193] The disclosed method enhances safety by preventing the electric bicycle from rolling backward on inclines, thereby providing a more secure riding experience, especially in hilly or mountainous terrain. By connecting both ends of the stator coil with a common voltage, the method simplifies the control logic required for the anti-rollback mode, potentially reducing the complexity and cost of the control unit. This approach utilizes existing components within the motor unit, such as the driver circuits, to achieve the antirollback functionality, which can lead to a more compact and integrated system design.

[0194] The motor acts as a generator and the connection to the common voltage generates a counter voltage acting against a rotation of the rotor. In one direction that prevents the bicycle from rolling back, because the chain will transmit that counterforce to the rear wheel, while in the other direction a freewheeling device provides a free rolling of the wheel despite the rotor being blocked.

[0195] Common voltage can refer to ground or power or any other common potential. A low-side switch may be a transistor used in a circuit to control the grounding of the load. It is connected between the load (in this case, a stator coil of the motor) and the ground. When the low-side switch is closed (turned on), it completes the circuit between the load and ground, allowing current to flow through the load to ground, thereby energizing the load. When the switch is open (turned off), it breaks the circuit, stopping the flow of current, and deactivating the load.

[0196] A high-side switch may be a transistor that is used to connect or disconnect the power supply to a load. It is placed between the power supply (voltage source) and the load. When the high-side switch is closed, it connects the load to the power supply, allowing current to flow through the load, powering it. When opened, it disconnects the load from the power supply, stopping the flow of current and deactivating the load.

[0197] Each stator coil can be connected at a connection point between a low-side switch and a high-side switch of a driver circuit. Connecting each stator coil at a connection point between a low-side switch and a high-side switch of a driver circuit allows for precise control of the motor's electromagnetic fields. The described connection scheme may enable easier diagnostics and maintenance of the motor unit, as it provides clear and direct access points for testing and servicing the driver circuits and their associated switches.

[0198] In a walk assist mode, the low-side switches may be turned on in order to connect the stator coils to ground potential. Turning on the low-side switches to connect the stator coils to ground potential in walk assist mode ensures a stable and controlled operation of the motor, which can enhance the user's confidence when maneuvering the bicycle at low speeds. This method can contribute to the longevity of the motor unit by providing a consistent electrical path that minimizes the risk of voltage spikes or irregular current flow, which can cause wear and damage over time. The grounding of stator coils through the low-side switches can improve the predictability of the motor's behavior, leading to a smoother transition between different operational modes of the electric bicycle.

[0199] The method may further comprise the steps of activating a walk assist mode with a powerpush mode, and wherein the anti-rollback mode is activated while the power-push mode is deactivated. Activating the anti-rollback mode while the power-push mode is deactivated ensures that the motor unit is not subjected to conflicting commands, which can prevent mechanical stress and potential system failures. This separation of modes allows for a clear distinction between assisting the rider in walking with the bicycle and actively propelling it forward, which can enhance the user interface and make the bicycle's operation more intuitive. The ability to selectively activate the anti-rollback mode independent of the power-push mode provides flexibility in how the electric bicycle can be used, catering to a wider range of user preferences and riding conditions.

[0200] In a power-push mode the driver circuits may energize the stator coils to push the bicycle in a forward direction. In power-push mode, energizing the stator coils to push the bicycle forward can offer riders a convenient and effortless way to move the bicycle without pedaling, which is particularly useful when carrying heavy loads or starting from a standstill. The driver circuits' ability to energize the stator coils for forward propulsion can lead to a more versatile electric bicycle that can assist users not only during riding but also when walking alongside the bicycle.

[0201] The stator coils may be only connected to ground solely by low-side switches. The exclusive connection of stator coils to ground via low-side switches simplifies the circuit design, potentially reducing manufacturing costs and enhancing reliability due to fewer components.

[0202] An anti-rollback mode may be part of a walk assist mode, and the walk-assist mode may be activated as long as a button is pressed by a user. Incorporating an anti-rollback mode within the walk assist mode enhances user safety by preventing unintended backward movement, especially on inclines, thereby increasing the confidence of the user during operation. Activation of the walk-assist mode through a button press allows for intuitive user control, ensuring that assistance is provided only when needed and conserving battery life when the function is not in use. Furthermore, a motor unit with a motor is provided. The motor may comprise a stator with at least one stator coil, and a control unit having at least two driver circuits. The stator coil can be connected with two driver circuits, such that the stator coil is connectable to power by a switch of one driver circuit and connectable to ground by a switch of the other driver circuit. The control unit may be configured to control the driver circuits to connect both ends of the stator coil with a common voltage, such that a voltage generated by rotation of a rotor acts against that rotation of the rotor.

[0203] The ability to connect both ends of a stator coil with a common voltage for generating a counter-electromotive force provides an effective method for electronic braking, which can rapidly decelerate the motor without additional mechanical components. The dual connection of the stator coil to two separate driver circuits allows for more versatile control strategies, including advanced modulation techniques that can optimize motor performance and efficiency across various operating conditions.

[0204] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0205] The motor unit may comprise one or more groups each having three stator coils and three driver circuits, each stator coil being connected with a different pair of driver circuits. The arrangement of motor stator coils in groups, each connected to different pairs of driver circuits, enables independent control of each coil group, which can lead to more precise motor control and smoother operation. This configuration allows for redundancy in the motor control system, which can increase reliability and maintain operation even if one of the driver circuits fails, thus enhancing the overall robustness of the motor system.

[0206] The motor unit may further comprise switches comprising field effect transistors and / or bipolar transistors. The use of switches comprising field effect transistors (FETs) and / or bipolar transistors allows for the selection of the most appropriate switch technology based on specific application requirements, such as voltage, current, switching speed, and thermal performance. FETs and bipolar transistors have different electrical characteristics that can be exploited to optimize the power efficiency and switching behavior of the motor control unit, potentially leading to energy savings and reduced heat generation during operation.

[0207] The control unit may be configured to turn on the switches in an anti-rollback mode to connect the stator coils to ground potential. The ability of the control unit to turn on the switches in an anti-rollback mode to connect the stator coils to ground potential enhances safety by preventing the bicycle from rolling back on inclines, thereby improving rider confidence. Connecting the stator coils to ground potential can provide a braking effect without the need for additional mechanical brake components, thus reducing the overall weight and maintenance requirements of the bicycle.

[0208] The control unit may be further configured to activate a walk assist mode with a powerpush mode, and to activate the anti-rollback mode while the power-push mode is deactivated.

[0209] The control unit's capability to activate a walk assist mode with a power-push mode offers the rider additional support when walking the bicycle, which can be particularly beneficial when navigating through tight spaces or crowded areas. The option to activate the antirollback mode while the power-push mode is deactivated allows for energy savings and optimized battery usage, as the system can selectively engage the necessary support functions based on the terrain and rider's needs.

[0210] The control unit may be configured to control the driver circuits to energize the stator coils to push the bicycle in a forward direction in the power-push mode. Controlling the driver circuits to energize the stator coils for propelling the bicycle forward in the power-push mode provides riders with an effortless way to start moving, especially from a stationary position, which can be advantageous for those with limited physical strength.

[0211] In further aspects that refer to elements of the angle-dependency of torque while driving and in walk-assist, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below. A method of controlling an electric bicycle is provided. The electric bicycle has a motor unit with a motor comprising a stator at least one stator coil, an angle detector measuring an angle around a transverse axis of the bicycle, and a control unit having at least two driver circuits each with a low-side switch and a high-side switch. At least one stator coil is connected with two driver circuits, such that the stator coil can be supplied with power by one of the driver circuits and connected with ground by the other driver circuit.

[0212] The method may comprise the step of measuring an angle around the transverse axis of the bicycle using the angle detector, and controlling the driver circuits to cause the motor to apply a torque for driving the bicycle, the torque depending on the angle.

[0213] The disclosed method enables dynamic adjustment of motor torque in response to the bicycle's orientation, thereby providing an optimized riding experience that adapts to varying terrain inclines. The frequent reading of the angle detector at intervals, such as every 4 milliseconds, allows for real-time control of the motor torque, resulting in a smooth and responsive assistance that closely matches the rider's immediate needs.

[0214] A torque may be increased with increasing angle. Incrementally increasing torque with the angle of incline ensures that the rider receives proportional assistance, making uphill climbs less strenuous and more manageable. The method's sensitivity to the angle of incline allows for efficient use of battery power, as the motor provides additional assistance only when needed, thereby extending the electric bicycle's range. By automatically adjusting the torque, the method reduces the need for manual gear changes or power setting adjustments by the rider, leading to a more intuitive and enjoyable cycling experience.

[0215] The torque may be applied at least in an assisted driving mode, in which a user of the bicycle applies a force to pedals and the motor generates the torque to enhance a torque resulting from that force. The assisted driving mode synergizes human effort with motorized assistance, which can reduce rider fatigue and enable longer rides without compromising the traditional cycling experience. The method's ability to enhance the torque resulting from the rider's pedaling effort ensures that the electric bicycle can maintain a consistent speed, even on challenging terrains, without overexerting the rider. By providing assistance in proportion to the rider's pedaling force, the method promotes efficient energy usage, as the motor's output is directly correlated with the rider's input.

[0216] The method torque may be applied at least in a power-push mode. Further, in the powerpush mode the driver circuits may energize the stator coils to push the bicycle in a forward direction with the torque, while a user of the bicycle pushes the bicycle without applying a force to pedals of the bicycle. The power-push mode provides convenience for users who need to maneuver the bicycle in pedestrian areas or tight spaces without the need to pedal, thereby expanding the functionality of the electric bicycle. By energizing the stator coils to push the bicycle forward, the method offers a motorized assistance that can be particularly useful when the rider is unable to pedal, such as due to injury or when carrying heavy loads. The power-push mode can serve as an aid for starting the bicycle's movement from a standstill, which can be especially helpful on steep inclines or when the rider is starting off with a heavy cargo load.

[0217] The power-push mode can be activated if a walk-assist mode is activated by pressing a first button, and then the power-push mode is active as long as a second button is pressed down. The activation of the power-push mode through a two-button sequence enhances safety by preventing accidental activation of the motor, ensuring that the bicycle is only propelled forward when the rider intentionally engages the system. The requirement to hold down a second button for the power-push mode to remain active provides an immediate means for the rider to disengage motor assistance, offering precise control over the bicycle's propulsion. The two-step activation process for the power-push mode allows for a clear distinction between different assistance modes, such as walk-assist and power-push, enabling the rider to select the most appropriate mode for the situation without confusion.

[0218] The method may comprise the following steps of recognizing a pattern out of a predefined set of patterns in an angle signal being a set of values of the angle during a period of time, and of applying a certain control mode in the control unit depending on the recognized pattern. The ability to recognize patterns in the angle signal allows for intelligent adaptation of the motor control strategy, enhancing the responsiveness of the system to changes in the riding conditions. By modifying stop conditions for the motor based on the recognized pattern, the system can prevent abrupt or unsafe stopping, thereby improving rider safety and comfort. The system's capability to distinguish between different patterns, such as drops or jumps, enables the application of tailored control modes that can optimize power consumption and extend the battery life of the bicycle.

[0219] Furthermore, a motor unit with a motor is provided. The motor may comprise a stator with at least one stator coil, an angle detector measuring an angle around a transverse axis of the bicycle, and a control unit having at least two driver circuits. The stator coil can be connected with two driver circuits, such that the stator coil is connectable to power by a switch of one driver circuit and connectable to ground by a switch of the other driver circuit.

[0220] The control unit may be configured to measure an angle around the transverse axis of the bicycle using the angle detector, and to control the driver circuits to energize the stator coils to push the bicycle in a forward direction with a specific torque, the torque being dependent on the angle.

[0221] The configuration of the stator coil with two driver circuits allows for precise control of the motor's power and grounding, leading to more efficient motor operation and improved battery usage. By measuring the angle around the transverse axis and controlling the torque accordingly, the system ensures that the bicycle maintains stability and traction, especially on inclines or uneven terrain. The specific torque control based on the detected angle provides a smoother riding experience, as the motor assistance is dynamically adjusted to the bicycle's orientation, enhancing rider comfort and control.

[0222] The control unit may be configured to increase the torque with increasing angle Increasing the torque with the increasing angle ensures that the motor provides adequate assistance when the bicycle is climbing hills, thereby reducing the effort required by the rider. The dynamic adjustment of torque in relation to the angle helps maintain a consistent speed and acceleration, improving the overall performance of the bicycle. This feature can contribute to the safety of the rider by preventing the bicycle from rolling backwards on steep inclines, as the increased torque can counteract the gravitational pull.

[0223] The control unit may be configured to apply the torque at least in an assisted driving mode, in which a user of the bicycle applies a force to pedals and the motor generates the torque to enhance a torque resulting from that force. In the assisted driving mode, the motor's torque enhancement complements the rider's pedaling effort, making it easier to cycle for longer distances or against strong headwinds. The synergy between the user's force on the pedals and the motor-generated torque can lead to a more natural riding experience, as the motor assistance feels like an extension of the rider's own power.

[0224] The motor unit further may be connected or connectable with a first switch and a second switch, and wherein the control unit may be configured to activate a walk-assist mode responsive to pressing the first button, and then holding the power-push mode activated as long as the second button is pressed down. The integration of a motor unit with dual switch connectivity enhances user interaction by providing a simplified control mechanism for different operational modes, thereby improving the ease of use and accessibility of the device .The ability of the control unit to maintain the power-push mode as long as the second button is pressed allows for continuous assistance without the need for repeated user input, which can reduce user fatigue and increase the efficiency of the device in assisting with mobility.

[0225] The skilled person will recognize that the advantages, technical effects and preferred embodiments discussed in connection with the method apply analogously to the motor unit. Likewise, all the advantages, technical effects and preferred embodiments described in connection with the motor unit are transferable to the method.

[0226] In further aspects that refer to elements of the detection of a stop intent of an e-bike, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0227] These aspects particularly address the problem of accurately detecting a user's stop intent while riding an e-bike to prevent unintended motor overrunning. The aspect provides solutions for identifying specific behavioral indicators, such as changes in pedal force and angle, that signify a rider's intention to slow down or stop. Current e-bike systems may not effectively recognize these indicators, leading to situations where the motor continues to assist after the rider has ceased pedaling, which can result in safety hazards and reduced control. By employing a combination of angle detection and force measurement sensors, the method aims to reliably determine when a rider intends to stop, allowing for timely disengagement of the motor to enhance user safety and control during operation.

[0228] A method is introduced for identifying when a user wants to stop an e-bike. Here, a "stop intent of a user" means the rider shows a clear action to slow down or stop, like reducing how hard they pedal, stopping pedaling, or using the brakes. An "e-bike" is a bike with an electric motor that helps with pedaling and is usually powered by a rechargeable battery.

[0229] The system includes a motor-unit with a motor and one freewheel. It also has an angle detector to measure the current pedal angle, which is the pedal's position in degrees compared to a set point, like when it's flat, at 0°. Additionally, there is at least one force measurement sensor to gauge both the amount and direction of force the user applies to the pedals.

[0230] The method involves a few steps: First, using the angle detector, it checks if the current angle of either the left or right pedal on the e-bike falls within a certain predetermined range. This "predetermined" range means it’s set in advance either as fixed numbers or based on some earlier calculations. Next, it starts measuring the force magnitudes and the direction of that force with at least one force measurement sensor, as long as the pedal is in that predetermined range.

[0231] If the measurement starts with the left pedal, the system checks if the force direction shows a decrease in the force magnitudes. Then, it assesses if this decrease is non- continuous, which might happen if there's a sudden drop in force or a distinct vertical force. This indicates that the user intends to stop, and a command is sent to disengage the motor to prevent it from continuing to run after the user stops pedaling. If the measurement starts with the right pedal, the system looks for an increase in force magnitudes. It then checks if this increase is non-continuous, which might be due to a sudden spike in force. This also suggests the user's intent to stop, and the motor is disengaged to prevent overrunning.

[0232] This method improves e-bike safety by quickly identifying when a rider wants to stop, which helps prevent accidents from delayed motor disengagement. By using both angle detection and force measurement, the method accurately and reliably detects stop intent, making the e-bike control system more responsive and intuitive. Plus, it efficiently detects when a user intends to stop, ensuring the motor is turned off in time to enhance safety and control.

[0233] In a further embodiment, the method includes adding at least one force measurement sensor, like a crank arm strain gauge sensor, on the left and / or right crank of the e-bike. This sensor detects tiny deformations from the rider’s pedaling force, turning this data into electrical signals to calculate torque and power output. By placing the sensor on the crank arms, we can measure pedaling forces more accurately, improving the e-bike's performance. This setup also provides a sleeker design that's less likely to get damaged or interfered with compared to sensors in other spots. Additionally, using the existing crank structure can make the sensor system simpler, lowering manufacturing costs and maintenance needs

[0234] In a further embodiment, the method includes setting a predetermined pedal angle range to match the switch of force from the left pedal to the right pedal or vice versa on the e- bike. By linking this angle range with the point where the force shifts between pedals, the system can accurately detect when the rider wants to stop. This improves accuracy and reliability, helping to differentiate between regular pedaling and actual stop intent while reducing false alarms. It also conserves computational power and sensor use, as it doesn't need to monitor for stop intent during the entire pedal cycle.

[0235] In a further embodiment, the method specifies a pedal angle range for the left pedal from 45° to 140°, ideally 75° to 140°. This angle range fine-tunes sensors monitoring pedal position, improving precise control for motor assistance. In a further embodiment, for the right pedal, the predetermined angle range is 195° to 295°, ideally 225° to 295°. This angle range fine-tunes sensors monitoring pedal position, improving precise control for motor assistance.

[0236] In a further embodiment, the method further comprises a predetermined pedal angle range being determined with respect to a neutral position of the left pedal or the right pedal of the e-bike. Determining the pedal angle range with respect to a neutral position ensures a consistent reference point for measuring pedal angles, which is crucial for accurate control of the e-bike's drive system. This approach allows for the calibration of sensors and the adjustment of the e-bike's software to account for variations in pedal position, leading to more reliable and responsive assistance from the electric motor.The neutral position-based pedal angle range can be used to implement safety features that prevent unintentional motor activation when the pedals are at rest or in an idle position.

[0237] In a further embodiment, the method further comprises a neutral position representing an angle of 0°. Defining a neutral position as an angle of 0° simplifies the design of the pedal angle detection system, as it provides a clear and unambiguous reference point for all related measurements.

[0238] In a further embodiment, the method further comprises a neutral position being determined based on a current biker state of the e-bike and / or a current seat angle parameter. Determining the neutral position based on the current biker state and / or seat angle parameter allows for dynamic adjustment of the e-bike's control systems to match the rider's posture and riding conditions, enhancing comfort and efficiency. This adaptive approach to defining the neutral position can lead to more accurately modulated motor assistance in response to the rider's actual needs.

[0239] In a further embodiment, the method further comprises if the measurement was initiated for the left pedal and it was determined that the decrease of force values is non- continuous, performing a cross-check of whether the user intents to stop by evaluating a secondary stopping criteria. In this case, the command to the motor-unit of the e-bike to disengage the motor is only transmitted if the cross-check also comes to the conclusion that the user intents to stop. A “cross-check” may refer to a supportive Query that crosschecks torque trends, vertical force signals, and other interference-prone parameters to confirm the stop intent. An operating criteria may be considered a stopping criteria, if the following command is associated with stopping the e-bike such as disengaging the motor. The inclusion of a cross-check enhances the reliability of the system by ensuring that a stopping event is not erroneously triggered.

[0240] In a further embodiment, the secondary stopping criteria use the number of local maxima in force magnitudes within a pedal angle range where the largest force is applied to the left pedal. Evaluating the amount of local maxima may be considered as a third operating criteria. If there's more than one local maxima, indicating a dip, it suggests a stop intent. This nuanced detection enhances safety and response by distinguishing deliberate stops from normal pedaling variations.

[0241] In a further embodiment, the pedal angle range for maximum force on the left pedal is 45° to 90°. Specifying a pedal angle range of 45° to 90° for the application of the largest force ensures that the system is calibrated to detect stopping intent during the most forceintensive portion of the pedaling cycle, which can lead to more accurate intent recognition.

[0242] In a further embodiment, the method further comprises if the measurement was initiated for the right pedal and it was determined that the increase of force values is non- continuous, the method further performing a cross-check of whether the user intents to stop by evaluating a secondary stopping criteria. In this case, the command to the motorunit of the e-bike to disengage the motor is only transmitted if the cross-check also comes to the conclusion that the user intents to stop.

[0243] The inclusion of a cross-check enhances the reliability of the system by ensuring that a stopping event is not erroneously triggered..

[0244] In a further embodiment, the method further comprises a secondary stopping criteria being based on an amount of local minima of force magnitudes measured within a pedal angle range during which the user applies the largest force to the right pedal. Evaluating the amount of local minima may be considered a fourth operating criteria. It is being checked whether there is a spike in the cos(x) force curve. Accordingly, if there is more than one local minima, a spike occurred which is an indication for a stop intent. If more than one local minima occurs, indicating a spike, it suggests a stop intent. This nuanced detection enhances safety and response by distinguishing deliberate stops from normal pedaling variations.

[0245] In a furhter embodiment, the method further comprises a pedal angle range during which the user applies the largest force to the right pedal being between 225°and 270° with respect to a neutral position. The specified pedal angle range for maximum force enhances stop intent detection by focusing on the most forceful pedaling period.

[0246] In a further embodiment, secondary stopping criteria use torque trends by deriving torque from force values to analyze pedaling patterns, enhancing stop intent detection and reducing errors. Checking if torque trends align with force direction ensures motor assistance matches the rider's intentions. A “torque trend” may refer to the pattern or variation of torque output over time, indicating changes in applied force, load conditions, or system performance in a mechanical or electrical system. A torque trend can be derived using only force sensors by continuously measuring the applied force at a known distance from the rotational axis (e. g. , crank or pedal), then calculating torque as torque = force * lever arm length, and analyzing the changes in torque over time to identify trends in force application during pedaling. Lever arm length refers to the perpendicular distance between the axis of rotation and the line of action of the applied force, determining the torque generated in a mechanical system.

[0247] In a further embodiment, the method further comprises obtaining raw sensor data from the force measurement sensor and applying noise filtering to the raw sensor data to obtain the force magnitudes and force directions. “Raw sensor data” may refer to the unprocessed and unfiltered output directly obtained from a sensor before any calibration, transformation, or computational adjustments are applied. “Noise filtering” is the process of removing unwanted variations or disturbances from raw sensor data to improve signal accuracy and reliability in measurements. In a further embodiment, applying noise filtering comprises comparing the raw sensor data to reference data indicating an ideal force curve and reducing the noise within the raw sensor data based on a deviation between the raw sensor data and the reference data, the deviation being a result of comparing the raw sensor data to the reference data. A “force curve” may refer to a force curve of force applied to the pedals of an e-bike that represents the variation in pedal force over a complete pedaling cycle, showing how the rider’s applied force changes with pedal angle. The “deviation between the raw sensor data and the reference data” may be the difference or discrepancy between the measured sensor output and the expected or predefined values, indicating potential measurement inaccuracies. Applying noise filtering by comparing raw sensor data to reference data improves the fidelity of the force curve analysis, leading to more accurate detection of the rider's intent.

[0248] A method is disclosed for detecting a stop intent on an e-bike. It involves getting sensor data that shows a force curve linked to a certain pedal angle range, checking if this data meets specific operating criteria, and sending a signal to adjust the e-bike's functions based on this check. This method improves control by quickly acting on changes like braking, based on sensor data. It lets the e-bike decide intelligently on the rider’s intent, making the interaction smoother and more user-friendly. The output signal helps create a dynamic ride as the e-bike automatically adjusts its behavior to the rider's actions.

[0249] In a further embodiment, the method further includes sensor data that measures force magnitude, direction on a pedal, and / or torque trend based on these forces. By understanding the force applied, torque can be calculated, which fine-tunes predicting and adapting to rider behavior for better performance and efficiency..

[0250] In a further embodiment, the method includes collecting sensor data from force sensors on the pedal or crank within the given pedal angle range. This setup ensures accurate data for real-time e-bike function control. Placing the sensors on the pedal or crank minimizes data errors, leading to a more reliable system. It also makes maintenance and replacement easier as these parts are more accessible. In a further embodiment, a first operating criteria relates to a, preferably continuous, decrease of force applied to a left pedal of the e-bike. Determining that the sensor information satisfies the first operating criteria thus comprises determining for the left pedal of the e-bike, that the sensor information indicates the, preferably continuous, decrease of force applied to the left pedal of the e-bike.

[0251] In a further embodiment, second operating criteria relates to a, preferably continuous, increase of force applied to a right pedal of the e-bike. Determining that the sensor information satisfies the second operating criteria thus comprises determining for the right pedal of the e-bike, that the sensor information indicates the, preferably continuous, increase of force applied to the right pedal of the e-bike.

[0252] In a further embodiment, the method includes a third operating criteria focused on detecting the maximum force applied to the left pedal of the e-bike. This maximum force is recorded within a specific pedal angle range that is associated with the maximum force applied to the left pedal. Determining if the sensor information meets this third criteria involves checking that the data shows a single peak force value on the left pedal.

[0253] In a further embodiment, the method includes a fourth operating criteria that focuses on identifying the minimum force applied to the right pedal of the e-bike. This minimum force is measured within a specific pedal angle range that is associated with the maximum force applied to the right pedal. To determine if the sensor information meets this fourth criteria, it checks whether the data reveals a single minimum force value on the right pedal.

[0254] In a further embodiment, the method prioritizes the first operating criteria as the primary one, which ensures that the most important factors are addressed first, making the system more efficent. The third operating criteria is used as a secondary criteria, offering a more detailed examination when needed. This helps to fine-tune decisions by taking additional factors into account, thereby enhancing the system's precision.

[0255] In a further embodiment, the method uses the second operating criteria as the main focus. This allows the system to emphasize different parameters that might be more suitable in specific situations, enhancing the system's flexibility. The fourth operating criteria is used as a backup, which helps the system make more precise and relevant decisions.

[0256] In a further embodiment, the method includes getting sensor data (1402) and then applying noise filtering to this data to get accurate sensor information.

[0257] In a further embodiment, applying noise filtering involves comparing sensor data to reference data that shows an ideal force curve. This comparison helps to remove noise from the sensor data, making sure the system uses accurate information. By reducing noise, the system becomes more sensitive and responsive, allowing for better control and operation of the e-bike.

[0258] There is disclosed a method for operating an e-bike, the method comprising: executing during operation of the e-bike the method for detecting a stop intent according to the method of any one of preceding embodiments, receiving a signal for adjusting the operation function of the e-bike and adjusting the operation function of the e-bike based on the received signal.

[0259] “During operation” refers to the period when the e-bike is actively in use, including pedaling, motor-assisted propulsion, braking, and other functional states while riding.

[0260] Executing the method for detecting stop intent during the operation of the e-bike ensures real-time responsiveness to the rider's actions, allowing for immediate adjustments to the e-bike's operation function.

[0261] In a further embodiment, adjusting the operation function comprises disengaging a motor of the e-bike, preferably to avoid overrunning. This enhances rider safety by preventing the motor from contributing to excessive speeds that could lead to loss of control or accidents.

[0262] There is disclosed a computer program or a computer-readable medium storing a computer program, wherein the computer program comprises instructions which when executed by a processor cause the processor to perform the method, of any one of the preceding embodiments.

[0263] There is disclosed a data-processing apparatus comprising means for performing the method, of any one of the preceding embodiments.

[0264] In a further embodiment, the means comprise a memory storing instructions for executing the method, of any one of the preceding embodiments andat least one processor coupled to the memory for executing the instructions stored within the memory.

[0265] There is disclosed an e-bike comprising the above-mentioned data-processing apparatus.

[0266] In a further embodiment, the e-bike also includes a motor-unit with a motor and a single freewheel. It features an angle detector to measure the current angle of a pedal and has at least one force measurement sensor to measure the force magnitudes and directions applied by the user to the pedal. A motor unit with a single freewheel simplifies the mechanical design of the e-bike, potentially reducing manufacturing costs and maintenance requirements due to fewer moving parts. Implementing only a force measurement sensor and not an additional torque sensor reduces hardware complexity and costs, as torque can be indirectly calculated from the force measurements, simplifying the overall system design.

[0267] There is disclosed a method of manufacturing an e-bike, preferably the e-bike according to the previous embodiments. This method involves providing an installation element. The installation element includes a computer program or computer-readable medium and / or a data-processing apparatus as described above. The method also involves installing this installation element into the e-bike.

[0268] In further aspects that refer to elements of the communication system with third-party components, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below. These aspects address the problem of integrating third-party components into e-bike systems that utilize incompatible communication protocols.

[0269] The application provides solutions for enabling seamless communication between a proprietary shifting system and the e-bike's control components, which typically operate on standard communication protocols such as CAN. The inability of these disparate systems to communicate effectively can lead to operational inefficiencies and hinder the functionality of the e-bike. The proposed methods facilitate the conversion of proprietary signaling into a compatible format, ensuring that critical data related to control functions, such as gear position and motor control, can be transmitted accurately and reliably between components, thereby addressing the challenges posed by protocol incompatibility. A control function of an e-bike refers to a programmed operation or algorithm that regulates key aspects of the e-bike's performance, such as motor assistance, braking, or power management, based on sensor inputs and user commands.

[0270] There is disclosed a method for integrating third-party components into an e-bike system, the method being performed by a secure CAN interface component between a third-party shifting system component and a component of the e-bike system, the method comprising: receiving, by the secure CAN interface component and from the third-party shifting system component, a first signaling, wherein the first signaling is based on a proprietary communication protocol which is incompatible with a CAN communication protocol used by the component of the e-bike system; converting, by the secure CAN interface component, the first signaling into a second signaling, wherein the second signaling is compatible with the CAN communication protocol used by the component of the e-bike system; and transmitting, by the secure CAN interface component and to the component of the e-bike system, the second signaling.

[0271] Integrating refers to the process of incorporating external hardware or software into a system. A third-party component is a hardware or software element developed by an external manufacturer or provider that can be integrated into a system to enhance or extend its functionality. A secure CAN interface component is a communication module designed to safely transmit and receive data between third-party components and system components of the e-bike while implementing security measures to prevent unauthorized access or data manipulation. A shifting system component is a component providing a mechanism that adjusts the gear ratio by controlling the derailleur or internal hub, allowing the rider to optimize pedaling efficiency and performance. A proprietary communication protocol is a custom-designed set of rules for data exchange, developed and controlled by a specific company or entity, restricting interoperability with components from other manufacturers. Converting a signal from an incompatible communication protocol into a compatible communication protocol involves translating or adapting the data format, structure, or transmission method to ensure seamless communication between different components.

[0272] The method allows components from different manufacturers to work together in an e- bike system. This method involves using a secure device to translate signals from a third- party component, such as a gear-shifting system that speaks its own unique language, into a language that the e-bike's main system understands. The secure device listens to the third-party component, changes its messages into a format that the e-bike can comprehend, and then sends these translated messages to the e-bike's main system so that they can work together smoothly. This process ensures that components designed with different communication protocols can still communicate effectively within the e-bike system.

[0273] The advantages of said method include enhancing the interoperability of the e-bike system by allowing the integration of third-party components that use proprietary communication protocols, thus increasing customization options for users. By translating incompatible signals into the e-bike’s native CAN protocol, it ensures seamless communication and performance between different system components, thus improving reliability and user experience. Furthermore, the secure CAN interface component acts as a protective barrier that can incorporate security measures to protect the e-bike's communication network from unauthorized access or interference, thereby enhancing overall system security. Additional benefits include improved controllability, adaptability, and automation, allowing for efficient communication management and the integration of diverse components without compatibility issues, while also enhancing system performance and user experience. There is disclosed a method for controlling communication at an e-bike, the method being performed by an intermediary component between a first component and a second component of the e-bike, the method comprising: receiving, by the intermediary component and from the first component, a first signaling, wherein the first signaling is based on a proprietary communication protocol which is incompatible with a communication protocol used by the second component; converting, by the intermediary component, the first signaling into a second signaling, wherein the second signaling is compatible with the communication protocol used by the second component; and transmitting, by the intermediary component and to the second component, the second signaling.

[0274] The method enables different parts of an e-bike system, which use different communication languages, to work together. It uses a special intermediary component (e.g., a secure CAN interface component) placed between two parts of the e-bike system. The first part may use a unique, proprietary language to communicate, which the second part cannot understand. The intermediary component takes the information from the first part, translates it into a language the second part can understand, and then sends it to the second part. This way, even if the parts each use their own communication protocols, they can still interact effectively.

[0275] The advantages of said method include the enhancement of component interoperability within the e-bike system, allowing manufacturers to select parts from a wider range of suppliers without worrying about compatibility issues due to differing communication protocols. The intermediary component facilitates the seamless integration of new functionalities or parts by translating protocols without needing major modifications to the existing system, thus saving time and reducing costs. Additionally, by minimizing the need for developing extra hardware or software to manage communications, the method can lead to significant cost efficiencies and simplify the maintenance and design processes for e-bikes.

[0276] In a further embodiment, the method further comprises a communication protocol used by the second component being a standard CAN protocol. This embodiment is about using a standard CAN protocol for the communication within an e-bike system. This involves ensuring that the second component of the e-bike uses a widely recognized communication protocol called CAN. By standardizing the protocol that the second component uses, the e-bike system can align itself with common industry practices, making it easier to integrate various components and systems.

[0277] The advantages of this embodiment include facilitating easier maintenance and troubleshooting, as the CAN protocol is well-known and widely supported in the industry. This standardization also improves the potential for future upgrades and compatibility, as many tools and resources are designed to work with CAN protocols. Additionally, using a standard CAN protocol often leads to enhanced network efficiency and reduced communication delays, as these protocols are optimized for performance and reliability in electronic systems.

[0278] In a further embodiment, the proprietary communication protocol used by the first component or by the third-party shifting system component is associated with a shifting system of the e-bike.

[0279] By associating the proprietary communication protocol with a shifting system of the e- bike, the method ensures that specialized functionalities and performance characteristics unique to the shifting system can be preserved and accurately translated for use within the e-bike's control system.

[0280] This association allows for the potential customization of the shifting experience, providing users with the ability to incorporate advanced or niche shifting systems that offer unique benefits over standard systems, thereby enhancing the overall value proposition of the e-bike.

[0281] In a further embodiment, communication between the first component and the second component is only possible using the intermediary component or communication between the third-party shifting system component and the component of the e-bike system is only possible using the secure CAN interface component. This embodiment describes a method that ensures certain components in an e-bike system can only communicate with each other through specific intermediary devices. For example, a first component and a second component within the e-bike must use an intermediary device to exchange information if their communication protocols are not compatible out of the box. Similarly, if a third-party shifting system wants to communicate with the e-bike's main system part, this can only happen through a secure CAN interface. This requirement creates a controlled communication pathway that guarantees proper integration and functionality of distinct system parts.

[0282] In a further embodiment, communication between the first component and the second component over the intermediary component is a unidirectional communication from the first component to the second component or wherein communication between the third- party shifting system component and the component of the e-bike (10) system over the secure CAN interface component is a unidirectional communication from the third-party shifting system component to the component of the e-bike system.

[0283] The unidirectional communication from the first component to the second component enhances system security by preventing potential backflow of sensitive data to the first (e.g., third-party) component. Unidirectional communication is a data transmission method where information flows in only one direction, from a sender to a receiver.

[0284] This configuration also simplifies the communication protocol, potentially reducing the processing overhead and power consumption associated with bidirectional communication, thereby improving the efficiency of the system.

[0285] In a further embodiment, the method further comprises unidirectional communication enabling the component to receive data from the third-party shifting system component while the third-party shifting system component is not able to receive data from the component. The unidirectional communication enables the second component to receive data from the first component while the first component is not able to receive data from the second component. The unidirectional communication enables the component to safely receive data without the risk of interference or corruption from the third-party shifting system component, ensuring the integrity of received data. This communication setup can be beneficial in scenarios where the third-party component is not trusted or certified to the same level as the main system, thus maintaining the overall system's reliability. It thus reduces the risk of unauthorized access or control of the component by the third-party shifting system component, enhancing the security posture of the e-bike system.

[0286] In a further embodiment, the first signaling is associated with a control function of the e- bike and the second signaling is associated with the same control function of the e-bike.

[0287] Associating the first and second signaling with the same control function of the e-bike ensures consistency in the control signals, leading to more predictable and stable system behavior. This way, it is ensured that the correct (i.e. , the intended) control function of the e-bike is controlled.

[0288] In a further embodiment, the control function comprises motor control, a display control or a diagnostic function of the e-bike.

[0289] Motor control, adjusting the power output or speed of the e-bike's motor to align with the desired riding conditions or user preferences. Display control refers to managing the information presented on the e-bike's display, such as speed, distance traveled, battery level, and other pertinent data. Lastly, diagnostic functions entail performing system checks and monitoring the health of the e-bike's components to identify any potential issues or required maintenance, ensuring the e-bike operates efficiently and safely.

[0290] In a further embodiment, the first signaling comprises a gear position, a cadence, a torque and / or a batter status.

[0291] The availability of said information can also facilitate advanced features such as automatic gear shifting or dynamic battery management, further improving the functionality of the e-bike. In a further embodiment, the method further comprises determining that the first signaling comprises data necessary and unnecessary for executing the control function of the e- bike. Converting the first signaling into the second signaling is then only based on the data necessary for executing the control function of the e-bike.

[0292] This embodiment describes a method where the system first examines the received signal to identify which parts of the data are important for carrying out a specific function of the e-bike, and which are not. This way, the method ensures that only the necessary information is converted into a new, compatible format for the e-bike’s system.

[0293] The advantage of this approach is that it enhances the efficiency of the e-bike’s control system. By processing only the necessary data, the system can respond faster to control requests, reducing the workload on the e-bike's processor. This not only potentially extends the battery life by lowering energy consumption but also minimizes the risk of errors by eliminating unnecessary data processing, thereby improving overall reliability and performance. Additionally, by filtering out unnecessary data before it enters the system component, the method enhances system security by preventing potentially malicious data from being processed or executed within the e-bike’s system. This protective measure contributes to maintaining the integrity and safety of the e-bike's operations.

[0294] In a further embodiment, the method further comprises filtering the unnecessary data from the first signaling to obtain a reduced signaling comprising only the data necessary for executing the control function. Then, converting the first signaling into the second signaling comprises converting the reduced signaling into the second signaling.

[0295] Filtering unnecessary data refers to the process of identifying and removing irrelevant, redundant, or harmful information from a data stream to improve efficiency, accuracy, and security within a system.

[0296] This embodiment describes a method where the system identifies and removes unnecessary data from an incoming signal to focus only on the essential information needed for a particular control function. This creates a simplified version of the signal, which then gets converted into a format that the e-bike system can use effectively.

[0297] The advantage of this approach is that it streamlines the data handling process, making it simpler and more efficient. By filtering out irrelevant information, the system reduces the complexity of the conversion process and minimizes the chance of data corruption. This method also enhances security by ensuring only necessary data is processed, protecting the e-bike system from potential threats.

[0298] In a further embodiment, the method further comprises determining that the first signaling comprises a first sub-signaling associated with a first control function of the e-bike and a second sub-signaling associated with a second control function of the e-bike, wherein the first control function is different from the second control function. The method further comprises determining that a priority associated with the first control function is higher than a priority associated with the second control function and converting and transmitting the converted first sub-signaling before converting and transmitting the second subsignaling.

[0299] The priority of a control function of an e-bike refers to the hierarchical importance assigned to a specific operational command or system response, determining its execution order relative to other functions for optimal performance and safety.

[0300] This embodiment describes a method where the system analyzes incoming signals to identify different sub-signals, each related to distinct control functions of the e-bike. It then determines which of these control functions should take precedence based on their assigned priorities. Once it establishes this priority order, the system ensures that subsignals related to higher-priority functions (e.g., motor control) are converted and transmitted before those with lower priorities (e.g., display control).

[0301] The advantage of this method is that it ensures critical functions receive attention first, maintaining the e-bike's essential operations even during high demand or in emergency scenarios. This prioritization allows the control system to be responsive and reliable, enhancing user experience by focusing on safety and performance. It also offers greater control flexibility, enabling the system to dynamically adjust based on the operational context by prioritizing different signals as needed.

[0302] In a further embodiment, converting comprises encrypting the second signaling.

[0303] This embodiment escribes a method where, during the signal conversion process in an e-bike system, the converted signal is encrypted. This means that once the signal has been transformed into a format compatible with the e-bike's communication protocol, it is further secured by encoding the information so that only authorized components with the correct decryption key can interpret it.

[0304] The advantage of this approach is that it significantly enhances the security of the communication within the e-bike system. By encrypting the data, the method prevents unauthorized access and manipulation of the signals as they are transmitted between components. This ensures that sensitive information within the control signals remains private and protected from potential interception. Additionally, this security measure helps maintain the safety and reliability of the e-bike's operations by preventing tampering with the control signals, which could otherwise lead to malfunctions or unsafe conditions.

[0305] There is disclosed a computer program or a computer-readable medium storing a computer program, wherein the computer program comprises instructions which when executed by a processor cause the processor to perform the method of any one of the preceding embodiments.

[0306] There is disclosed a data-processing apparatus comprising means for performing the method of any one of the preceding embodiments.

[0307] In one embodiment, the means comprise a memory storing instructions for executing the method of any one of the preceding embodiments and at least one processor coupled to the memory for executing the instructions stored within the memory.

[0308] There is disclosed an e-bike comprising the data-processing apparatus of the preceding embodiments. There is disclosed a method of manufacturing an e-bike, preferably the e-bike according to the preceding embodiment. The method comprises providing an installation element, the installation element comprising a computer program or computer readable-medium according to the preceding embodiment and / or a data-processing apparatus according to the preceding embodiments and deploying the installation element into the e-bike.

[0309] In further aspects that refer to elements of the app-display communication using Bluetooth Low Energy, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0310] These aspects address the problem of inefficient data synchronization between the display unit of an e-bike and a mobile application on a smart device.

[0311] The application provides solutions for the challenges faced by e-bike users in accessing and managing real-time ride metrics and route planning information. Current systems often lack seamless communication, leading to delays in data transfer and inadequate integration of navigation and performance metrics. This results in a fragmented user experience, where riders cannot effectively monitor their ride performance or receive timely updates on navigation, road conditions, and other relevant data. The proposed method aims to establish a reliable BLE-based synchronization mechanism that ensures timely and accurate data exchange between the e-bike's display unit and a mobile application, thereby enhancing the overall functionality and usability of e-bike systems.

[0312] Embodiments of the application are associated with various advantages and / or technical effects.

[0313] There is disclosed a method for BLE-based synchronization of data between a display unit of an e-bike and a mobile application running on a smart device, wherein e-bike uses a platform-based communication management for the synchronization, wherein the mobile-application utilizes a GPS-based navigation. For data synchronization from the mobile application to the display unit, the method comprises: determining, by the mobile application using the GPS-based navigation, route planning information for route a user of the e-bike is taking, transmitting, by the mobile application using BLE and to the display unit, the route planning information and displaying the route planning information on a display of the display unit. For data synchronization from the display unit to the mobile application, the method comprises: obtaining, by the display unit, data about real-time ride metrics of the e-bike, displaying, by the display unit, the data on the display of the display unit and transmitting, by the display unit using BLE and to the mobile application, the data.

[0314] Data synchronization is the process of ensuring that data across multiple devices, systems, or system components is consistent, up-to-date, and accurately aligned in real time or at scheduled intervals. A smart device is an electronic device equipped with sensors, connectivity, and processing capabilities that enable it to collect data, interact with users, and communicate with other devices such as smartphones or smartwatches. Route planning information refers to data used to determine the most efficient or preferred path for a journey based on factors such as distance, terrain, traffic, and user preferences. Real-time ride metrics of an e-bike refer to continuously updated data collected during a ride, providing insights into performance, efficiency, and rider effort.

[0315] This way, a method for synchronizing data between an e-bike's display and a mobile app using Bluetooth Low Energy (BLE) is provided. This process involves two key pathways. First, the mobile app, leveraging GPS-based navigation, plans the route for the e-bike user and transmits this information to the display on the e-bike using BLE, allowing the rider to see the route directly on the e-bike's display. Second, the e-bike display unit collects real-time riding data, like speed and distance, and sends this back to the mobile app via BLE. This bidirectional communication ensures that both the mobile app and e- bike display have the latest ride information. This method enhances user experience by integrating GPS-based route planning with real-time display, offering seamless navigation and ride management. Moreover, it improves safety by allowing cyclists to concentrate on the road while receiving directions, minimizing the need to handle mobile devices. Additionally, using BLE facilitates quicker data transfer, ensuring timely synchronization of essential ride and navigation information. In a further embodiment, the display of the display unit is mounted on handlebars of the e-bike.

[0316] Handlebars of an e-bike are the steering component mounted on the front of the frame, configured to provide rider control, support mounted accessories, and house control elements such as brakes, gear shifters, and display units.

[0317] This positioning facilitates easy access to ride information during the journey, minimizing distractions and supporting better control of the e-bike. The proximity to the rider's natural line of sight ensures optimal visibility, thereby allowing the rider to interpret and respond to the data swiftly and safely.

[0318] In a further embodiment, the data about real-time ride metrics comprises speed, cadence, power output, torque, distance traveled, elevation gain, battery level, motor assistance level, ride duration and / or fitness information. The fitness information may comprise a heart rate of the user during the ride, calories burned by the user and / or recovery metrics.

[0319] This embodiment discusses the various real-time ride metrics monitored by the method, which include data points like speed, cadence, power output, torque, distance traveled, and elevation gain, among others. Fitness information such as heart rate, calories burned, and recovery metrics are optionally included. This comprehensive monitoring enables riders to gain insights into their performance, tailor fitness goals, and make instant adjustments to optimize their ride performance and battery use

[0320] In a further embodiment, the route planning information comprises travel distance, elevation profile, estimated travel time, turn-by-turn navigation, road conditions, traffic data, weather conditions, alternative routes, waypoints, and / or points of interest.

[0321] This embodiment specifies the details included in route planning information, such as travel distance, elevation profile, estimated travel time, turn-by-turn navigation, road conditions, traffic and weather data, alternative routes, and waypoints. These elements enrich the ride planning and experience by offering detailed navigation and enhancing decision-making for better safety and satisfaction. In a further embodiment, the platform-based communication management is configured to synchronize data from a plurality of sensor of the e-bike to collect the data about realtime ride metric of the e-bike.

[0322] The Plurality of sensors may comprise a speed sensor, cadence sensor, torque sensor, force sensor, pedal angle sensor, gyroscope, accelerometer, battery sensor, motor temperature sensor, brake sensor, ambient light sensor, GPS module, heart rate sensor and / or wheel rotation sensor.

[0323] This embodiment presents a communication management approach that synchronizes data from multiple e-bike sensors, providing a comprehensive view of real-time ride metrics. By integrating sensor data, users receive the most accurate and updated performance insights, enabling precise evaluation and enhanced diagnostics, which could predict maintenance needs and extend the e-bike's lifespan.

[0324] In a further embodiment, the method further comprises receiving, by the mobile application, the data about real-time ride metrics and storing the data in the smart device for later monitoring of the data by the user.

[0325] This embodiment describes how the method allows the mobile application to receive and store real-time ride data. Users can later review this data, promoting user engagement by providing interactive feedback and enabling analysis without the need for continuous internet access, thus supporting performance improvement and goal setting.

[0326] In a further embodiment, the method further comprises obtaining, by the mobile application, a user input for modifying a configuration of the e-bike. The configuration may comprise a requested motor performance level and / or an assist level of the motor of the e-bike.

[0327] This embodiment explains how users can input and modify the e-bike’s configuration through the mobile application, specifically regarding motor performance and assist levels, allowing for a personalized riding experience. This customization can optimize energy efficiency and potentially prolong the e-bike’s battery life by setting appropriate assistance levels according to personal preference and riding conditions.

[0328] There is disclosed a method of BLE-based synchronization of data between a display unit of an e-bike and a mobile application running on a smart device. The method comprises determining that new data to be synchronized is available at either the display unit or the mobile application and transmitting, using BLE, the new data from the display unit to the mobile application or from the mobile application to the display unit to synchronize the new data.

[0329] This way a more generic process for BLE-based synchronization is provided, where the system identifies when new data is available from either the display unit or mobile application and transmits this new data to ensure both devices are updated with the latest information. The method ensures real-time data accessibility and maintains ride metrics' accuracy while being energy-efficient due to BLE’s low-power consumption.

[0330] There is disclosed a computer program or a computer-readable medium storing a computer program, wherein the computer program comprises instructions which when executed by a processor cause the processor to perform the method(s) of any one of the preceding embodiments.

[0331] There is disclosed a data-processing apparatus comprising means for performing the method(s) of any one of the preceding embodiments.

[0332] In a further embodiment, the means comprise a memory storing instructions for executing the method(s) of any one of the preceding embodiments and at least one processor coupled to the memory for executing the instructions stored within the memory.

[0333] There is disclosed an e-bike comprising the data-processing apparatus of any one of the preceding embodiments.

[0334] There is disclosed a method of manufacturing an e-bike, preferably the e-bike according to the preceding embodiment. The method comprises providing an installation element and deploying the installation element into the e-bike. The installation element comprises a computer program or computer readable-medium according to the preceding embodiment and / or a data-processing apparatus according to the preceding embodiment.

[0335] In further aspects that refer to elements of the Bluetooth-based location tracking software, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0336] These aspects address the problem of effectively tracking e-bikes to prevent theft and unauthorized use.

[0337] The application provides solutions for accurately estimating the location of an e-bike using Bluetooth technology in conjunction with user devices in proximity, while ensuring the privacy of user data. The method incorporates a secure broadcasting mechanism for the e-bike's unique serial number and Bluetooth address, enabling passive tracking without direct user interaction. Additionally, it addresses scenarios where Bluetooth-based location determination may fail by integrating GPS and cellular communication modules to maintain continuous tracking capabilities, particularly in cases of unauthorized movement or when Bluetooth signals are unavailable.

[0338] Embodiments of the application are associated with various advantages and / or technical effects.

[0339] There is disclosed a method for tracking an e-bike. The method comprises broadcasting, via a Bluetooth module within an e-bike, a broadcast signal comprising a unique serial number of the e-bike and a Bluetooth address of the Bluetooth module, receiving signals of one or more Bluetooth-enabled user devices which detected the broadcast signal, wherein the one or more Bluetooth-enabled user devices are in close proximity to the e- bike and are configured to automatically scan for broadcast signals, estimating a location of the e-bike based on the received signals of the one or more Bluetooth-enabled user devices and providing the location and the unique serial number of the e-bike to a tracking system. A Bluetooth address is a unique identifier assigned to a Bluetooth-enabled device, used for communication and identification within Bluetooth networks. Bluetooth-enabled user device refers to electronic devices capable of wireless communication using Bluetooth technology, including but not limited to smartphones, tablets, laptops, smartwatches, and other wearable or connected device. A broadcast signal is a wireless transmission of data from a device to multiple receivers within range, typically used for communication, identification, or location tracking. Close proximity, e.g., in the context of BLE, refers to a short-range distance, typically within a few meters, where Bluetooth-enabled devices can reliably communicate and exchange data while preferably maintaining low power consumption. A tracking system is a system that collects, processes, and stores location data of an e-bike based on signals received from Bluetooth-enabled user devices, GPS modules, or cellular communication. The system uses this location data to provide tracking updates, determine movement patterns, enable theft detection, and allow authorized users to retrieve real-time or historical location information.

[0340] In this embodiment, the method involves tracking an e-bike by using a Bluetooth module built into the e-bike to send out a signal that includes the bike's unique serial number and Bluetooth address. Nearby user devices equipped with Bluetooth automatically detect this signal, and these detections help estimate the bike's location. This information, alongside the bike's serial number, is then sent to a tracking system. The advantages of this method include utilizing widely available Bluetooth technology for cost-effective tracking, improving the chances of recovering lost or stolen bikes. It also allows for precise identification of specific bikes, which assists in verifying ownership.

[0341] In a further embodiment, the method further comprises determining a signal strength of each of the received signals and estimating a distance between the e-bike and each of the Bluetooth-enabled user devices based on the corresponding signal strength of the respective signal. In this embodiment, estimating the location of the e-bike comprises computing the estimated position of the e-bike based on the estimated distances between the e-bike and each of the Bluetooth-enabled user devices, preferably using trilateration. A signal strength can be determined by measuring the power level of a received Bluetooth signal at the detecting device, with the signal strength decreasing as the distance between the transmitter and receiver increases. For trilateration, a location is calculated by measuring the distance from at least three known points (e.g., BLE-enabled devices) and using geometric principles to pinpoint the exact position.

[0342] In this embodiment, the method enhances the basic tracking approach by determining the signal strength of the received Bluetooth signals to estimate distances from the e-bike to each detected device. The bike's location is then calculated using these distances, preferably through a process called trilateration. This method introduces the advantage of more accurate location estimation by considering signal strength and spatial calculations, enhancing the reliability of tracking systems.

[0343] In a further embodiment, the Bluetooth address is assigned by the e-bike manufacturer and stored in a secure database, preventing direct linkage to personal user data.

[0344] In this embodiment, the method involves assigning the Bluetooth address at the manufacturing stage and storing it securely, which prevents linking it directly to personal user data. This enhances the security of the tracking system by protecting user privacy. It also simplifies the tracking process for manufacturers and service providers due to the standardized approach from the production stage.

[0345] In a further embodiment, the method further comprises a tracking system operating passively by leveraging Bluetooth-enabled user equipment’s Bluetooth scanning capabilities without requiring direct user interaction.

[0346] In this embodiment, the tracking system operates without requiring direct user interaction by leveraging Bluetooth-enabled user devices that automatically detect the e-bike's broadcast signal. The system's passive nature eliminates the need for active participation, making it energy-efficient and less intrusive, thereby promoting easier adoption by users.

[0347] In a further embodiment, the method further comprises anonymizing the Bluetooth address to ensure no personally identifiable information is exposed. In this embodiment, the method includes anonymizing the Bluetooth address to ensure that no personal information of the e-bike users is disclosed through the tracking process. This approach protects user privacy and helps comply with privacy regulations, reducing potential data privacy risks and increasing acceptance among privacy-conscious users.

[0348] In a further embodiment, the Bluetooth module is part of a display unit of the e-bike.

[0349] In this embodiment, the Bluetooth module is integrated into the e-bike's display unit. This design choice consolidates multiple functionalities into one component, reducing complexity and potential points of failure.

[0350] In a further embodiment, the e-bike comprises an GPS module configured to determine the location of the e-bike in real time.

[0351] Real time in this context refers to at least faster than Bluetooth based location determination.

[0352] In this embodiment, the e-bike is equipped with a GPS module for real-time location tracking. This lays the groundwork for advanced security features like theft prevention by allowing the bike's real-time monitoring.

[0353] In a further embodiment, the GPS module is activated to determine the location of the e- bike in real time upon detecting unauthorized movement of the e-bike.

[0354] Unauthorized movement of the e-bike refers to any detected motion or displacement of the e-bike that occurs outside predefined user-authorized conditions, such as unexpected location changes, movement while locked, or deviations from a geofenced area, indicative of potential theft or misuse.

[0355] In this embodiment, the GPS module is activated to determine the e-bike’s location in real time when unauthorized movement is detected. This targeted use of the GPS module optimizes power consumption, conserving battery life for regular operations. The feature serves as a deterrent to theft and aids in the rapid recovery of the e-bike, enhancing overall security.

[0356] In a further embodiment, detecting unauthorized movement of the e-bike comprises determining that the location of the e-bike determined based on the received signals of the one or more Bluetooth-enabled user devices is outside a predefined area.

[0357] A predefined area refers to a geographical boundary set by the user or system, such as a geofenced zone, home location, or designated parking area, within which the e-bike is expected to remain; movement beyond this boundary may trigger alerts or tracking activation.

[0358] In this embodiment, unauthorized movement is detected based on whether the e-bike is located outside a predefined area using Bluetooth signals from surrounding devices. This method employs a low-energy efficient process, extending battery life by avoiding continuous GPS use, and allows for customizable boundaries and alerts for a personalized security setup.

[0359] In a further embodiment, the GPS module is activated if Bluetooth-based location determination is not possible, in particular if no signals from Bluetooth-enabled user devices are received or if estimating the location of the e-bike based on the received signals of the one or more Bluetooth-enabled user devices yields no result.

[0360] For example, signals may not be received if no devices are in close proximity of the e- bike.

[0361] In this embodiment, the GPS module is activated as a backup when Bluetooth-based location determination is not possible. This ensures that the e-bike remains traceable even without Bluetooth signals, providing a robust security system. The dual-method approach increases tracking reliability under varied conditions by using both Bluetooth and GPS technologies. In a further embodiment, the e-bike comprises a cellular communication module configured to transmit the location of the e-bike to the tracking system.

[0362] In this embodiment, the e-bike includes a cellular communication module to send its location to the tracking system. This facilitates remote monitoring and enhances real-time tracking, important for theft deterrence and recovery. Cellular networks provide extensive coverage, increasing connectivity reliability and enabling additional services like remote control (e.g., locking the e-bike).

[0363] In a further embodiment, the cellular communication module is activated upon a user request or upon detecting unauthorized movement of the e-bike.

[0364] A user request refers to an action initiated by the user, such as a command, input, or selection, to trigger a specific function or operation within a system, such as enabling realtime tracking, retrieving location data, or activating the cellular communication module.

[0365] In this embodiment, the cellular communication module is activated by a user request or when unauthorized movement is detected. This feature provides a proactive security measure, allowing for immediate responses to potential theft. By conserving battery life via selective activation, it extends operational time between charges and reinforces the bike's security system.

[0366] In a further embodiment, the GPS module and the cellular communication module are operating in conjunction to enable hybrid of the e-bike.

[0367] Hybrid tracking of the e-bike refers to a tracking method that dynamically combines Bluetooth-based passive tracking, GPS-based real-time location tracking, and cellular communication to optimize accuracy, energy efficiency, and coverage based on available network conditions and user preferences.

[0368] In this embodiment, the GPS and cellular communication modules operate together to create a hybrid positioning system. This system compensates for the limitations of each technology, like GPS signal loss or weak cellular connectivity, offering precise and reliable location tracking. The hybrid approach improves security features such as geofencing.

[0369] There is disclosed a computer program or a computer-readable medium storing a computer program, wherein the computer program comprises instructions which when executed by a processor cause the processor to perform the method(s) of any one of the preceding embodiments.

[0370] There is disclosed a data-processing apparatus comprising means for performing the method(s) of any one of the preceding embodiments.

[0371] In a further embodiment, the means comprise a memory storing instructions for executing the method(s) of any one of the preceding embodiments and at least one processor coupled to the memory for executing the instructions stored within the memory.

[0372] There is disclosed an e-bike comprising the data-processing apparatus of any one of the preceding embodiments.

[0373] There is disclosed a method of manufacturing an e-bike, preferably the e-bike according to the preceding embodiment. The method comprises providing an installation element and deploying the installation element into the e-bike. The installation element comprises a computer program or computer readable-medium according to the preceding embodiment and / or a data-processing apparatus according to the preceding embodiment.

[0374] In further aspects that refer to elements of the housing of a motor, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0375] These aspects particularly address the problem of ensuring safety and effective cooling in the housing of electric bicycle motors. These aspects provides solutions for the design of a motor housing that incorporates cooling ribs. Additionally, the arrangement of the motor within the housing and its integration into the bicycle frame addresses the need for a compact and secure configuration that does not compromise the structural integrity or performance of the electric bicycle.

[0376] There is disclosed a housing for a motor of an electric bicycle, comprising an outer casing and a plurality of cooling ribs. The cooling ribs are positioned on the outer casing and protrude outwards from it. The outer surfaces of the cooling ribs have one, some, or all dimensions measuring at most 50 mm.

[0377] A dimension is especially any dimension of a surface being touchable from the outside. An outer surface is especially a surface which is touchable from the outside.

[0378] The provision of cooling ribs with outer surfaces having dimensions at most 50 mm ensures that the housing is safe to touch, reducing the risk of injury from sharp edges or protrusions. Alternatively to using a dimension of 50 mm, a value of 10 mm, 20 mm, 30 mm, 40 mm, 60 mm, 70 mm, or 80 mm can be used as upper end.

[0379] The design minimizes the possibility of snagging clothing or other materials on the cooling ribs, enhancing the user's experience and safety during operation or maintenance.

[0380] The specified maximum dimension of the cooling ribs' outer surfaces allows for a compact and aesthetically pleasing design, potentially increasing the marketability of the electric bicycle.

[0381] The cooling ribs provide the advantage of improved heat dissipation from the motor, enhancing overall performance and longevity.

[0382] In a development, the housing further comprises all or some cooling ribs extending along a circumference of the outer casing. The purpose of this is to achieve good cooling by headwind, especially if an axis of the motor casing is oriented perpendicular to a plane of a bicycle frame.

[0383] Cooling ribs extending along the circumference of the outer casing can effectively utilize headwind to dissipate heat, improving the motor's thermal management during highspeed travel.

[0384] The circumferential arrangement of the cooling ribs can contribute to a more uniform distribution of cooling airflow around the motor housing, leading to more consistent temperature regulation.

[0385] This configuration may also enhance the structural integrity of the housing by providing additional support and rigidity where the ribs are integrated with the outer casing.

[0386] The housing may comprise one or more grooves, each groove separating two immediately neighboring cooling ribs.

[0387] The inclusion of grooves separating neighboring cooling ribs allows for compliance with the dimension requirement, ensuring safety without compromising the cooling functionality.

[0388] Grooves between the ribs can create turbulence in the airflow, potentially increasing the heat dissipation efficiency by disturbing the boundary layer of air adjacent to the housing.

[0389] The grooves provide visual cues that can aid in the identification of individual ribs, facilitating easier inspection and maintenance of the housing.

[0390] In a development, the housing comprises one or more grooves extending perpendicular to a longitudinal extension of the ribs.

[0391] A groove typically spans over several cooling ribs.

[0392] Additional grooves may be oriented parallel to the ribs in order to separate them. Grooves extending perpendicular to the longitudinal extension of the ribs can interrupt the thermal conduction path, potentially reducing heat transfer to areas of the housing that do not require cooling.

[0393] These perpendicular grooves can act as channels for directing airflow more effectively across the surface of the ribs, enhancing the overall cooling performance.

[0394] The perpendicular orientation of the grooves may contribute to an increase in the mechanical strength of the housing by creating a cross-bracing effect.

[0395] In a development, the housing comprises grooves having a depth of at least 10 mm or 12 mm. This can especially help to prevent a standard finger from reaching the bottom.

[0396] Grooves with a depth of at least 10 mm or 12 mm prevent a standard finger from reaching the bottom, thereby increasing safety by reducing the risk of accidental contact with potentially hot surfaces.

[0397] The specified depth of the grooves can accommodate larger volumes of airflow, which may improve the convective cooling efficiency of the housing.

[0398] Deep grooves can also serve as a protective measure against the ingress of debris, which could otherwise accumulate and impede the cooling performance or damage the motor.

[0399] In a development, the housing further comprises grooves having a U-shape and / or have a half circle shape.

[0400] The shape of a groove is especially defined at least between adjacent cooling ribs.

[0401] The U-shaped or half-circle-shaped grooves between adjacent cooling ribs enhance the structural integrity of the housing while allowing for efficient airflow, which improves the cooling performance of the motor unit. In sense of the application, a motor unit may refer to a motor arrangement. These groove shapes facilitate the accumulation and channeling of air or cooling fluid, thereby optimizing heat dissipation from the electric motor and potentially extending its operational lifespan.

[0402] In a development, the outer casing encompasses an interior space for accommodating an electric motor.

[0403] The outer casing encompassing an interior space provides a protective barrier for the electric motor, safeguarding it from environmental contaminants such as dust, moisture, and debris, which could otherwise impair motor function.

[0404] The design of the outer casing allows for a compact and integrated motor unit, which can lead to a reduction in the overall size and weight of the motor system, beneficial for applications where space and weight are critical factors.

[0405] These aspects further relate to a motor unit comprising a housing as described herein and an electric motor, wherein the electric motor is positioned inside the housing, specifically within an interior space of the outer casing.

[0406] Positioning the electric motor inside the housing ensures a direct and secure connection between the motor and the housing, which can result in improved mechanical stability and reduced vibration during operation.

[0407] The interior space of the outer casing is tailored to the electric motor, which can enhance thermal management by ensuring that the motor is surrounded by materials with appropriate thermal conductivity, thus aiding in maintaining optimal operating temperatures.

[0408] In a development, the arrangement further comprises a chainring being adapted to at least partially shield a side surface of the housing.

[0409] The side surface especially extends perpendicular to the extension of the spindle. The chainring's ability to at least partially shield the side surface of the housing can protect the housing from external physical impacts and reduce the accumulation of dirt or debris, which might otherwise compromise the cooling efficiency or mechanical integrity of the housing.

[0410] By shielding the side surface, the chainring also contributes to the aerodynamic profile of the motor unit, potentially reducing drag and improving the energy efficiency of the system when in motion.

[0411] In a development, the chainring may be mounted rotatably fixed on the spindle. Thus, there is no need for a separate output wheel.

[0412] Mounting the chainring rotatably fixed on the spindle eliminates the need for a separate output wheel, which simplifies the motor unit design and can reduce manufacturing costs and assembly time.

[0413] This configuration ensures a direct transfer of torque from the motor to the chainring without the need for additional transmission components, which can improve the overall mechanical efficiency and responsiveness of the power transfer system.

[0414] These aspects further relate to an electric bicycle comprising a frame and a motor unit as disclosed herein, wherein the motor unit is embedded in the frame.

[0415] Embedding the motor unit within the frame provides a sleek and integrated design, reducing the overall profile of the electric bicycle and enhancing its aesthetic appeal.

[0416] The integration of the motor into the frame can improve the structural integrity of the bicycle, as the motor can contribute to the frame's rigidity and strength.

[0417] By embedding the motor, the center of gravity of the bicycle may be lowered, improving stability and handling characteristics during operation. In a development, the frame comprises a cutout at its lower side. The motor unit may be embedded in the cutout.

[0418] The cutout in the frame's lower side allows for a more compact motor unit, which can lead to a reduction in the bicycle's weight and an increase in energy efficiency.

[0419] Positioning the motor unit within the cutout can protect the motor from external elements such as road debris, water, and dust, potentially extending the motor's lifespan and reducing maintenance needs.

[0420] The cutout design facilitates easier access to the motor for maintenance or replacement, as it provides a designated space that can be specifically engineered for serviceability.

[0421] In a development, the frame partially overlaps one or both side surfaces of the housing of the motor unit.

[0422] The frame partially overlapping the motor housing's side surfaces can provide additional protection to the motor from lateral impacts, enhancing the durability of the electric bicycle.

[0423] This design can also shield the motor from the elements and reduce the ingress of contaminants, which can improve the reliability and performance of the motor over time.

[0424] The partial overlap may also contribute to the bicycle's aerodynamics by smoothing the transition between the frame and the motor housing, potentially reducing air resistance during travel.

[0425] In a development, exposed parts of one or both side surfaces between the spindle and the frame have a radial extension of not more than 50 mm.

[0426] Limiting the radial extension of exposed parts between the spindle and the frame to a minimal dimension can reduce the risk of snagging clothing or objects, increasing rider safety. A smaller radial extension can also contribute to a more streamlined appearance, enhancing the visual integration of the motor with the bicycle frame.

[0427] The reduced exposure of the motor's side surfaces minimizes the surface area that is susceptible to damage from external impacts, potentially leading to lower repair costs and improved longevity of the motor components.

[0428] The term "bicycle" may be used herein to refer to a bicycle especially which is operated by an electric motor.

[0429] An "electric bicycle" may designate a bicycle that is driven by an electric motor.

[0430] The term "frame" as used herein may refer to a frame that supports the motor unit of the electric bicycle.

[0431] The term "cutout" may refer to a partial hole in the frame.

[0432] The term "housing" may refer to a housing for a motor, wherein the cooling ribs may be positioned on the outer casing.

[0433] The term "spindle" may refer to a spindle of a motor unit for an electric bicycle, wherein the spindle may be driven by an electric motor.

[0434] The term "outer casing" may refer to the outer casing from which the cooling ribs may extend.

[0435] A "first side surface" may designate a surface that may not be touchable from the outside, especially due to the chainring.

[0436] A "second side surface" may designate a surface that is opposite to the first side surface.

[0437] The term "exposed parts" may, for example, be understood to mean exposed parts of the side surfaces. The term "cooling ribs" may refer to cooling ribs that may be located on the outer casing and may protrude outwards from the outer surface.

[0438] A "first groove" may designate a groove in the outer surface and / or between the cooling ribs.

[0439] A "second groove" may designate a groove that may be located on the outer surface of the housing and / or between the cooling ribs.

[0440] The term "motor unit" as used herein may refer to an arrangement with a spindle that may be drivable by the electric motor.

[0441] An "electric motor" may designate a motor that may be used to drive a spindle, which in turn may drive a chainring.

[0442] The term "outer surfaces" may refer to any surface that may be touchable from the outside.

[0443] The term "interior space" may refer to a space of the housing for a motor of an electric bicycle.

[0444] The term "increased safety" may refer to increased protection for people touching the outer surfaces.

[0445] The term "good cooling" may refer to the ability of the cooling ribs to provide good cooling, for example, by headwind.

[0446] An "immediately neighboring cooling rib" may designate cooling ribs that may be immediately adjacent to each other.

[0447] A "dimension" may designate, in particular, the dimension of the outer surface of the cooling ribs. The term "longitudinal extension" may be understood to mean an extension parallel to the longitudinal direction of the ribs.

[0448] The term "standard finger" may refer to a typical human finger.

[0449] An "adjacent cooling rib" may designate a cooling rib that may be immediately neighboring another cooling rib.

[0450] A "separate output wheel" may designate a wheel that may be driven by a separate motor.

[0451] The term "radial extension" may refer to the extension of the radial length, for example, of the exposed parts of one or both side surfaces between the spindle and the frame.

[0452] Further, these aspects related to the housing of a motor may also be described as follows, with particular reference to the Figures.

[0453] There is disclosed a housing (the term housing may be used herein to refer to a housing used in an electric bicycle, where the cooling ribs may be located on the outer casing) for a motor (the term motor may be used herein to refer to electric motors) of an electric bicycle (a bicycle which may be driven by an electric motor), the housing comprising an outer casing and a plurality of cooling ribs.

[0454] The cooling ribs (the term cooling ribs may be used herein to refer to the cooling ribs of the housing for an electric bicycle) may be positioned on the outer casing and may protrude outwards from an outer surface.

[0455] The cooling ribs have outer surfaces [an outer surface is a surface (the term surfaces may be used herein especially to refer to any dimension which may be touchable from the outside) which may be touchable from the outside] with one, some or all dimensions (the term dimensions may be used herein to refer to any dimension which may be touchable from the outside) especially being at most 50 mm. Purpose: increased safety for people (the term "increased safety for people" may be used herein to refer to a reduction in the risk of injury or death caused by electric bicycles) touching the outer surfaces.

[0456] In a development, the housing may further comprise all or some cooling ribs extending along a circumference (the term "circumference" may refer to the circumference of the outer casing) of the outer casing.

[0457] The housing may comprise one or more grooves (any grooves, holes, cavities, grooves, slots, channels, or the like, which may be formed in the outer casing of the housing), each groove may separate two immediately neighboring cooling ribs (cooling ribs which may be immediately adjacent to each other).

[0458] In a development, the housing may further comprise one or more grooves extending perpendicular to a longitudinal extension (the term "longitudinal extension" may be understood to mean an extension along the longitudinal direction of the ribs) of the ribs (the term "ribs" may be used herein to refer to the cooling ribs).

[0459] In a development, the housing may further comprise grooves having a depth (the term "depth" may be used herein to refer to the dimension of the groove) of at least 10 mm or 12 mm [to prevent a standard finger (the term "standard finger" may be used herein to refer to a finger of a human) from reaching the bottom].

[0460] In a development, the housing may further comprise grooves having a U-shape (a shape having a U-shape in a cross-section perpendicular to the longitudinal extension of the ribs) and / or having a half-circle shape (a shape that may be circular in a plane but is not necessarily circular in a three-dimensional space).

[0461] In a development, the housing may further comprise an outer casing encompassing an interior space (the term "interior space" may be used herein to refer to an area of the housing for a motor of an electric bicycle) for accommodating an electric motor (a motor that may be used to drive the bicycle). Motor unit (the term "motor unit" may be used herein to refer to an arrangement with a motor of an electric bicycle), comprising a housing according to one of the preceding embodiments and an electric motor, wherein the electric motor may be positioned inside the housing, especially inside an interior space of the outer casing.

[0462] In a development, the arrangement may further comprise a chainring (the term "chainring" may be understood to refer to a structure that includes teeth for driving a chain), which may be adapted to at least partially shield a side surface of the housing.

[0463] The side surface may extend perpendicular to the extension (the term "extension" may be used to refer to the extension along a length that is perpendicular to the longitudinal direction) of the spindle (the term "spindle" may be understood to refer to a spindle of the electric bicycle)].

[0464] In a development, the arrangement may further comprise a chainring being mounted rotatably fixed on the spindle. Thus, there may be no need for a separate output wheel (a wheel that may not be directly connected to the spindle)].

[0465] The application may further relate to an electric bicycle, comprising a frame (the term "frame" may be understood to mean a structure that comprises a cutout at its lower side, wherein the motor unit may be embedded therein) and a motor unit as disclosed herein, wherein the motor unit may be embedded in the frame.

[0466] In a development, the bicycle (the term "bicycle" may be used herein to refer to a bicycle in which the motor unit of the electric bicycle may be embedded) may further comprise a frame comprising a cutout (the term "cutout" may be understood to refer to a cutout at the lower side) at its lower side (the term "lower" may be used herein to refer to the side of the bicycle that is lower than the other side), wherein the motor unit may be embedded in the cutout.

[0467] In a development, the bicycle may further comprise exposed parts of one or both side surfaces between the spindle and the frame, having a radial extension (the term "radial extension" may be understood to refer to an extension of the radii between the spindle and the frame) of not more than 50 mm.

[0468] There is disclosed a housing for a motor of an electric bicycle, the housing comprising an outer casing and a plurality of cooling ribs, the cooling ribs being positioned on the outer casing and protruding outwards from the outer surface (exterior, external face, skin, shell, facade, veneer, covering, finish, coat, layer), wherein the cooling ribs have outer surfaces with one, some, or all dimensions (measurements, sizes, proportions, extents, magnitudes, scales, breadths, widths, lengths, gauges) being at most 50 mm.

[0469] The purpose is: increased safety for people (enhanced protection for individuals, improved safeguarding for persons, heightened security for humans, amplified defense for users, elevated precaution for consumers, advanced care for bystanders, greater assurance for the public, stronger shield for people, better guard for folks, more safety for citizens) touching the outer surfaces.

[0470] A dimension is especially any dimension that may be touchable from the outside.

[0471] In a development, the housing may further comprise all or some cooling ribs extending along a circumference (perimeter, girth, outline, boundary, edge, border, contour, periphery, circuit, ambit) of the outer casing.

[0472] The purpose is: good cooling by headwind (efficient ventilation by oncoming air, effective heat dissipation by frontal wind, optimal temperature reduction by airstream, superior air- cooling by approaching breeze, enhanced thermoregulation by forward wind, improved cooling by incoming airflow, favorable chilling by direct wind, beneficial heat exchange by headwind, effective temperature control by oncoming draft).

[0473] The housing may comprise one or more grooves, each groove separating two immediately neighboring (directly adjacent, next-door, contiguous, abutting, bordering, adjoining, touching, proximate, nearby, close) cooling ribs. This may be done especially in order to comply with the dimension requirement (measurement stipulation, size condition, proportion prerequisite, extent specification, magnitude obligation, scale necessity, breadth criterion, width mandate, length requisite, gauge demand). In a development, the housing may further comprise one or more grooves extending perpendicular to a longitudinal extension (lengthwise stretch, longwise continuation, linear prolongation, elongated expansion, lengthened extension, longitudinal enlargement, long-drawn-out extension, extended lengthening, protracted stretching, drawn-out growth) of the ribs.

[0474] A groove may typically span over several cooling ribs.

[0475] In a development, the housing may comprise grooves having a depth (deepness, profundity, pit, cavity, hollow, indentation, concavity, depression, drop, chasm) of at least 10 mm or 12 mm. This is especially to prevent a standard finger (typical digit, normal phalange, regular finger, common finger, usual finger, ordinary finger, standard appendage, conventional finger, average finger, customary finger) from reaching the bottom.

[0476] In a development, the housing may comprise grooves having a U-shape (horseshoe form, U-forrn, Il-contour, U-configuration, U-profile, U-outline, U-figure, U-silhouette, ll-cut, II- pattern) and / or a half-circle shape (semicircular form, half-round contour, demi-circle configuration, semi-oval outline, hemispherical shape, half-disc figure, semi-circular silhouette, bisected circle form, half-moon contour, semi-orb configuration).

[0477] The shape (form, contour, configuration, outline, figure, silhouette, profile, pattern, mold, model) of a groove is typically defined at least between adjacent (neighboring, adjoining, contiguous, proximate, bordering, abutting, nearby, next to, touching, alongside) cooling ribs.

[0478] In a development, the outer casing may encompass an interior space (internal area, inside compartment, inner chamber, enclosed volume, interior cavity, internal zone, inner section, enclosed space, interior region, inner enclosure) for accommodating an electric motor (electrical engine, electronic motor, power motor, electric machine, electrical mover, electronic engine, electric drive, electrical power unit, electronic mover, electric propulsion system). A motor unit may comprise a housing as described herein and an electric motor, wherein the electric motor may be positioned inside the housing.

[0479] In a development, the arrangement may further comprise a chainring being adapted to at least partially shield a side surface (lateral face, flank, sidewall, edge, side area, lateral area, side plane, lateral plane, side exterior, lateral exterior) of the housing.

[0480] A side surface especially extends perpendicular to the extension of the spindle (axle, rod, shaft, pivot, pin, mandrel, arbor, axis, fulcrum, staff).

[0481] In a development, the arrangement may further comprise a chainring being mounted rotatably fixed on the spindle. Thus, there may be no need for a separate output wheel (independent drive wheel, distinct power wheel, separate propulsion wheel, individual driving wheel, discrete motive wheel, standalone output gear, unattached drive gear, isolated driving gear, independent rotary wheel, separate transmission wheel).

[0482] There is also disclosed an electric bicycle (e-bike, power-assisted bicycle, motorized bicycle, electric bike, pedal-assist bike, battery-powered bicycle, electrically driven bicycle, motor-assisted cycle, electric cycle, powered bicycle), comprising a frame (chassis, structure, skeleton, framework, support, body, substructure, armature, construction) and a motor unit as described herein.

[0483] The motor unit may be embedded in the frame.

[0484] In a development, the frame may comprise a cutout (notch, opening, aperture, slot, hole, gap, incision, groove, indentation) at its lower (bottom, beneath, under, nether, base, lowermost, inferior, underside, downward, sub) side. The motor unit may be embedded in the cutout.

[0485] In a development, the bicycle may further comprise a frame partially overlapping one or both side surfaces of the housing of the motor unit. In a development, the bicycle may be constructed such that exposed (uncovered, revealed, bare, open, visible, unprotected, unshielded, accessible, displayed, out in the open) parts of one or both side surfaces between the spindle and the frame have a radial extension (radial stretch, radial reach, radial span, radial length, radial expansion, radial extent, radial scope, radial range, radial sweep, radial protrusion) of not more than 50 mm.

[0486] In further aspects that refer to elements of the operating system for an e-bike controller or more generally for an electromechanical apparatus, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0487] In this context, a control architecture for an electromechanical apparatus is provided. The control architecture may comprise a firmware distribution server, a plurality of target nodes, each of which can correspond to a component of the electromechanical apparatus, and a communication interface.

[0488] The firmware distribution server may be configured to store and provide one or more firmware updates. The target nodes can be configured to autonomously retrieve firmware updates by independently initiating a request to the firmware distribution server. The communication interface is preferably configured to enable data exchange between the target nodes and the firmware distribution server.

[0489] This control architecture is particularly well suited for Over the Air firmware update systems.

[0490] By comparison, existing Over the Air solutions typically rely on a centralized controller that actively distributes updates to each component. This centralized approach presents several limitations. Updates are often carried out sequentially rather than simultaneously, leading to increased overall downtime. Moreover, the central controller constitutes a single point of failure, which can compromise the reliability of the entire update process. The control architecture presented here addresses these limitations through a decentralized approach based on autonomous update retrieval. Instead of having a central unit that distributes updates to the components, each target node, such as a motor controller, battery management system or display, initiates its own update process by checking for available firmware and downloading it as needed. This enables updates to take place in parallel, reducing total update time and avoiding the risk of a single point of failure.

[0491] In contrast to conventional push-based firmware update systems, where a central controller actively distributes updates to passive components, the disclosed architecture introduces a pull-based model in which each target node autonomously initiates and controls the update process.

[0492] Overall, the architecture offers several important advantages. It improves system robustness by decentralizing the update process. It reduces the need for service intervention by allowing components to manage their own updates. It accelerates update execution through simultaneous processing. It scales effectively with the number of components in the system. And it improves the user experience by supporting mobilebased interaction and flexible control.

[0493] The communication interface may comprise a Controller Area Network (CAN) bus, which offers robust and efficient data exchange between components. As a proven standard in automotive and e-bike applications, the CAN bus enables reliable communication even under challenging conditions, with built-in error detection and message prioritization.

[0494] Using a CAN bus allows the firmware distribution server and target nodes to interact over an existing, minimal-wiring infrastructure. This supports parallel firmware updates, reduces complexity, and ensures real-time responsiveness, making the system more scalable and resilient.

[0495] As used herein, a "target node" may refer to a functional component of the electromechanical apparatus that is capable of receiving, storing, and executing firmware updates. Each target node may preferably comprise a processing unit and / or a memory, and can be configured to independently initiate a request to a firmware distribution server in order to retrieve a corresponding firmware update. A target node may be associated with, or functionally assigned to, a specific physical component of the apparatus - such as a motor, battery system, or display unit - which it may monitor, control, or manage with respect to firmware functionality.

[0496] As described above, the target nodes may be configured to autonomously retrieve firmware updates by initiating a request to the firmware distribution server without relying on centralized control. In this context, "autonomously" preferably refers to the ability of each target node to independently assess whether certain predefined conditions are met and to act accordingly. Such conditions may include, for example, the expiration of a timer, a relevant change in system state, the reception of a notification from the firmware distribution server, or user input received via an associated interface. Depending on the implementation, the update request may therefore be triggered either automatically- based on internal logic and system events - or manually in response to user interaction.

[0497] For instance, a display unit may offer an update prompt to the user and, upon confirmation, initiate the update process for itself or other components connected via the communication interface.

[0498] As another example, a motor control unit may be configured to monitor its operational hours or firmware version and, upon reaching a predefined threshold or detecting the availability of a newer version, may initiate a firmware update request without requiring any external command. In this case, the trigger condition is internally determined based on usage data, allowing the update process to occur during low-power or idle states, thereby minimizing disruption to normal operation.

[0499] In some embodiments, the control architecture may further comprise a second firmware distribution server coupled to the communication interface. The second firmware distribution server may serve as a fallback or redundant source for firmware updates, thereby increasing system robustness and availability in case the primary server is unreachable or offline. Alternatively or additionally, the second server may be used to host region-specific, component-specific, or experimental firmware versions. The electromechanical apparatus may be any system comprising interconnected electronic and mechanical components that require firmware management, such as an electric bicycle, an electric scooter, a robotic system, or an industrial automation device. In preferred embodiments, the electromechanical apparatus is an electric bicycle including components such as a motor unit, a battery management system, a display interface, and / or one or more sensors. Each of these components may be associated with a respective target node configured to participate in the decentralized firmware update architecture.

[0500] According to certain embodiments, the electromechanical apparatus may be implemented as an electric bicycle comprising the control architecture as previously described. The electric bicycle may include multiple functional components, each associated with a respective target node capable of independently retrieving firmware updates.

[0501] In one exemplary embodiment, a battery management system (BMS) of the electric bicycle may serve as a first target node. The BMS is preferably configured not only to manage charging, discharging, and cell balancing operations, but also to participate in the firmware update system. In some configurations, the firmware distribution server may be hosted directly on the BMS itself, enabling localized storage and distribution of firmware updates within the electric bicycle.

[0502] This arrangement may offer several technical advantages. Hosting the firmware distribution server on the BMS reduces dependency on external infrastructure, enhances update availability even in offline or service-tool-assisted scenarios, and simplifies communication with other onboard target nodes such as a motor controller, a display unit, or sensor modules. Furthermore, because the BMS typically remains powered even when other components are inactive, it provides a reliable platform for managing scheduled or event-triggered update cycles.

[0503] The integration of the firmware distribution server within the BMS also allows for hybrid architectures, where updates may be pulled from an external remote server when connectivity is available, and cached locally within the BMS for later distribution. This supports flexible update strategies, including offline servicing, over-the-air updates, and peer-to-peer firmware propagation between bicycles or via mobile service tools.

[0504] In further embodiments, the electromechanical apparatus may comprise additional target nodes associated with distinct functional subsystems of the electric bicycle. For example, a second target node may correspond to a control unit of a motor unit, which is typically responsible for regulating drive power, interpreting sensor signals such as cadence or torque input, and implementing various assistance modes. Within the context of the firmware update architecture, this control unit may be capable of monitoring its firmware version, detecting update availability, and autonomously initiating a corresponding update process. This decentralized approach eliminates the need for centralized coordination and enables efficient update execution during suitable operating states, such as idle or maintenance phases.

[0505] A third target node may be implemented as a display unit, which may serve both as a graphical interface and an integral part of the update system. In addition to visualizing system information, the display unit may be configured to act as a communication router, bridging data exchange between an external mobile device and the internal communication interface of the apparatus- preferably via a Bluetooth Low Energy (BLE) module or a comparable wireless protocol.

[0506] Furthermore, the display unit may operate as a user interface that supports bidirectional interaction with the update process. It may inform the user about available firmware versions, display progress or status messages, and allow manual control inputs, such as confirming an update or adjusting preferences. Interaction can take place via touchscreen, physical buttons, or other suitable controls integrated into the display. This functionality enables direct user engagement without relying on external tools, although mobile devices or service equipment may optionally be used in parallel.

[0507] The combined roles of the display unit - as both a communication gateway and an input / output interface - facilitate flexible integration into various system topologies. Depending on the specific configuration, the apparatus may support automated updates, user-initiated update sequences, or mixed approaches adapted to operational and userspecific needs.

[0508] In a further preferred embodiment, the application relates to a system for updating firmware of an electromechanical apparatus, the system comprising the electromechanical apparatus according to any embodiments described above and a mobile device.

[0509] The mobile device may be configured to establish data communication with the firmware distribution server, for example via a wireless interface such as Bluetooth Low Energy (BLE), Wi-Fi, or a cellular connection. This configuration allows the mobile device to serve as an external interface for initiating or managing firmware updates, retrieving update packages from a remote source, or transmitting update-related control data to the apparatus.

[0510] In this respect, the mobile device may be configured to establish wireless communication with a third target node of the apparatus. This third target node may be implemented as the display unit, which is further configured to function as a communication router. In this role, the display unit acts as an intermediary between the mobile device and the internal communication infrastructure of the apparatus. The mobile device may transmit firmware update data, version information, update commands, or authentication credentials to the display unit via a wireless protocol, preferably Bluetooth Low Energy (BLE). The display unit may then forward the received data via the internal communication interface - such as a Controller Area Network (CAN) bus - to the firmware distribution server or to other target nodes of the system. This configuration allows the mobile device to participate in the update process without requiring direct physical access to each target node or to the firmware distribution server.

[0511] It is apparent that bidirectional communication may also be supported, whereby the firmware distribution server can transmit signals via the communication interface and the third target node, i.e. the display unit acting as a router, back to the mobile device. The system architecture thereby supports flexible update strategies, including Over the Air updates that can be initiated by the user or automatically triggered based on predefined conditions. Compared to traditional firmware update systems, where for example firmware updates for electric bicycle components require users to visit a dealer and use a dealer service tool to manually update each component, Over the Air systems offer significant advantages. The traditional process is often inconvenient, time consuming, and dependent on specialized hardware that is not available to all dealers.

[0512] In a further configuration, the system may comprise a remote server that is configured to be in data communication with the firmware distribution server of the apparatus. The firmware distribution server may synchronize with the remote server to retrieve available firmware updates, transmit device status or version information, or receive configuration parameters for controlled update behavior. The communication interface of the apparatus may in this case include a communication module, such as a wireless modem or transceiver (e.g., Wi-Fi, LTE, or other mobile standard), which enables wireless data exchange with the remote server. This infrastructure supports cloud-based firmware management, centralized update distribution, and scalable multi-device administration across a fleet of electromechanical systems.

[0513] The remote server may also be in data communication with the mobile device. This allows the mobile device to act as a bridge or proxy between the remote server and the electromechanical apparatus, particularly in cases where the apparatus does not have direct access to the internet or cloud infrastructure. The mobile device may download firmware update packages from the remote server, cache them temporarily, and then transmit them to the apparatus via the display unit acting as a communication router. This hybrid configuration is especially useful in mobile environments or in field applications where permanent connectivity of the apparatus cannot be guaranteed.

[0514] Furthermore, the system may include a service tool that may be designed to support maintenance, diagnostics, and / or firmware updates. This service tool may either be implemented as a dedicated hardware unit, such as a workshop terminal, or as a software- based solution running on a mobile or desktop device. In preferred embodiments, the service tool may comprise an integrated firmware distribution server that is capable of communicating with a remote server to download update packages, receive authentication keys, or synchronize system configurations. In such cases, the service tool may function as a local update source, particularly in environments where reliable network access is not available. To enable communication with the electromechanical apparatus, the service tool may include a suitable interface, which may be wireless, such as Bluetooth Low Energy or Wi-Fi, or wired, such as USB or a serial connection, for coupling to the communication interface of the apparatus.

[0515] Through the inclusion of such a service tool, the system enables flexible firmware management scenarios, including offline updates, in-shop diagnostics, bulk updates for multiple devices, and fallback procedures in case of failed over-the-air update attempts.

[0516] This comprehensive system architecture provides a high degree of redundancy, flexibility, and user accessibility, supporting various usage contexts such as private consumers, professional service networks, and connected fleet operators. It facilitates both autonomous and user-controlled update processes and ensures reliable and secure firmware provisioning across different connectivity levels.

[0517] In addition to the system described above, the present disclosure also relates to a method for updating firmware in an electromechanical apparatus comprising a plurality of target nodes and at least one firmware distribution server. The method reflects the decentralized architecture of the system and enables reliable, scalable, and flexible firmware management without the need for centralized control or constant dealer involvement.

[0518] The method comprises independently initiating, by each of at least one of the target nodes, a request to retrieve a corresponding firmware update. These requests are not centrally coordinated but rather triggered on a per-node basis, allowing each component to manage its own update cycle. In response to such a request, the firmware distribution server transmits the requested firmware update to the respective target node via a communication interface, which may be a wired system such as a CAN bus or a wireless connection, depending on the system configuration. The architecture permits multiple target nodes to retrieve and apply their respective updates simultaneously, thereby reducing total update time and avoiding unnecessary system downtime. In some embodiments, the method further comprises notifying one or more of the target nodes of the availability of firmware updates. This notification may be generated by the firmware distribution server and communicated through the existing communication interface. A target node receiving such a notification may then autonomously decide to initiate a firmware update request based on internal conditions or user-defined policies.

[0519] The initiation of a request by a target node may occur manually via a user interface, such as a display unit integrated into the apparatus. In this context, the user may trigger the update process by confirming an update prompt, adjusting settings, or actively selecting specific components for updating. Alternatively, the initiation may be automated based on predefined conditions, including the expiration of a timer, detection of a system state change, or the reception of a notification indicating that an update is available.

[0520] In addition to internal logic, the firmware distribution server itself may obtain update data from external sources. Accordingly, the method may further comprise receiving firmware update data at the firmware distribution server from a remote server via a wireless communication module. This enables the apparatus to synchronize with cloud-based update infrastructures or central fleet management systems.

[0521] Furthermore, firmware update data may be transmitted from a mobile device to the firmware distribution server. In such cases, the data may be routed through a target node functioning as a communication router, such as a display unit equipped with a Bluetooth Low Energy module. This approach facilitates over-the-air updates initiated by the user through a smartphone or similar device.

[0522] Finally, the method may also support wired or wireless data transmission from a service tool to the firmware distribution server. This enables offline updates or dealer-supported update procedures where external network connectivity is unavailable or undesired. The service tool may provide locally stored update packages or act as an intermediary for authenticated firmware distribution in controlled environments. Overall, the method provides a flexible and robust framework for maintaining firmware consistency and security across all critical components of the electromechanical apparatus, supporting both autonomous and user-driven update workflows.

[0523] In further aspects that refer to elements of the gearwheel design with hardened steel and PEEK., various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0524] These aspects, in particular, address the problem of inefficiencies and complexities in the design and manufacturing of output wheels for pin ring gears in electric drive arrangements.

[0525] The disclosure provides solutions for the challenges associated with the need for precise coaxial alignment and the reduction of radial extension in output wheel designs. Traditional configurations often involve multiple components that can lead to increased manufacturing complexity, potential misalignment, and additional interfaces that may compromise performance. The integration of the gearwheel and sleeve into a one-piece component aims to streamline the assembly process and enhance the structural integrity of the output wheel, while also addressing issues related to material selection and weight reduction in electric drive systems.

[0526] Embodiments of the application are associated with various advantages and / or technical effects.

[0527] There is disclosed an output wheel for a pin ring gear of an electric drive arrangement, the output wheel comprising:

[0528] - a gearwheel, and

[0529] - a sleeve,

[0530] - wherein the gearwheel and the sleeve are preferably embodied as a one-piece component such that the gearwheel extends radially outward from the sleeve and

[0531] - wherein the sleeve provides a plain bearing for a spindle inside the sleeve The integration of the gearwheel and the sleeve into a single component eliminates the need for separate assembly processes, thereby reducing manufacturing complexity and potential assembly errors.

[0532] The absence of an interface between the gearwheel and the sleeve minimizes radial dimensions, which can lead to a more compact design, beneficial for applications where space is at a premium.

[0533] The one-piece construction ensures improved coaxial alignment between the gearwheel and the sleeve, enhancing the operational reliability and longevity of the electric drive arrangement.

[0534] The design provides the advantage of flexibility, allowing for various configurations and adaptations in electric drive arrangements to meet specific performance requirements.

[0535] The materials used in the output wheel enhance its force conductive properties, improving efficiency in power transmission within the electric drive arrangement.

[0536] The one-piece construction of the output wheel contributes to manufacturability, simplifying the production process and reducing assembly time.

[0537] The modular design of the electric drive arrangement facilitates easy replacement and upgrades of components, enhancing overall system versatility.

[0538] The use of durable materials and design features ensures longevity and reliability of the electric drive arrangement, reducing maintenance needs and extending the product lifecycle.

[0539] In a development, the wheel further comprises a gearwheel and the sleeve being made of the same material. Utilizing the same material for both the gearwheel and the sleeve simplifies the procurement and inventory management of raw materials, leading to cost savings in production.

[0540] The uniform material properties across the gearwheel and sleeve can result in consistent thermal expansion behavior, reducing the risk of misalignment or fit issues during temperature fluctuations.

[0541] The homogeneity of material can also facilitate recycling or reprocessing of the component at the end of its lifecycle, supporting environmental sustainability efforts.

[0542] In a development, the wheel further comprises a gearwheel and the sleeve being made of Polyether Ether Ketone (PEEK).

[0543] This material reduces weight, increases wear resistance, and has a low coefficient of friction with hardened steel.

[0544] The use of Polyether Ether Ketone (PEEK) for both the gearwheel and the sleeve significantly reduces the overall weight of the output wheel, contributing to the efficiency and performance of the electric drive arrangement.

[0545] PEEK'S inherent wear resistance extends the service life of the output wheel, especially in applications involving frequent or high-speed rotations.

[0546] The low coefficient of friction between PEEK and hardened steel reduces energy losses due to friction, enhancing the overall efficiency of the system.

[0547] In a development, the wheel further comprises a gearwheel and the sleeve forming an L- shape in a part of a cross-section on one side of a symmetry axis.

[0548] This can increase the moment of inertia, leading to improved torque transmission capabilities. This L-shaped configuration may also contribute to a more even distribution of stress within the component, potentially reducing the likelihood of material fatigue and failure.

[0549] The asymmetrical design allows for the optimization of material usage, where it is most structurally beneficial, potentially leading to further weight reduction without compromising strength.

[0550] In a development, the wheel further comprises a gearwheel seen in a cross-section, widening in radial direction from a middle part towards a radial outer part

[0551] The radial widening of the gearwheel from the middle part towards the outer part can enhance the load-bearing capacity of the teeth, allowing for the transmission of higher forces.

[0552] This design feature may also contribute to a more uniform distribution of contact stresses along the tooth profile, reducing the risk of tooth breakage or wear.

[0553] The gradual increase in cross-sectional area towards the outer part can provide additional material where it is needed most, potentially allowing for a lighter overall design without sacrificing performance.

[0554] In a development, the wheel further comprises that the gearwheel seen in a cross-section, widens in radial direction from a middle part towards the sleeve

[0555] Thus, the middle part can being made with less material, reducing weight.

[0556] The radial widening of the gearwheel from the middle part towards the sleeve contributes to a reduction in material usage, thereby decreasing the overall weight of the wheel and enhancing efficiency in applications where the wheel is utilized.

[0557] The optimized distribution of material in the gearwheel design ensures that strength is maintained where necessary, particularly towards the sleeve where force transmission occurs, without compromising the structural integrity of the wheel. In a development, the wheel further comprises the gearwheel extending perpendicular to a longitudinal extension of the sleeve

[0558] The perpendicular orientation of the gearwheel relative to the longitudinal extension of the sleeve allows for a compact assembly, which is beneficial in applications with limited space.

[0559] This configuration facilitates the efficient transfer of torque from the gearwheel to the spindle, ensuring effective power transmission in the drive system.

[0560] In a development, an output wheel comprises

[0561] - a gearwheel, and

[0562] - a sleeve,

[0563] - wherein the gearwheel and the sleeve are embodied as a one-piece component such that the gearwheel extends radially outward from the sleeve,

[0564] - wherein the sleeve provides a plain bearing for a spindle inside the sleeve, and

[0565] - wherein the gearwheel and the sleeve are made of the same material, namely Polyether Ether Ketone (PEEK).

[0566] The one-piece construction of the gearwheel and sleeve eliminates the need for separate assembly processes, reducing manufacturing complexity and potential points of failure.

[0567] The use of PEEK material for both the gearwheel and sleeve ensures uniform thermal expansion and material properties throughout the component, enhancing the reliability and performance of the bearing system.

[0568] The integration of the plain bearing within the sleeve provides a low-friction interface for the spindle, which can lead to reduced wear and longer service life of the component.

[0569] Electric drive arrangement, the electric drive arrangement comprising:

[0570] - a spindle

[0571] - an electric motor having an output shaft and - a pin ring gear being driven by the output shaft and comprising an output wheel according to one of the preceding embodiments.

[0572] The spindle may be made of hardened steel.

[0573] The hardened steel spindle offers high resistance to wear and deformation, ensuring that the electric drive arrangement maintains its precision and efficiency over extended periods of use.

[0574] The inclusion of an output wheel as described in the preceding embodiments allows for a tailored integration of the wheel's unique features, such as weight reduction and material optimization, into the electric drive arrangement, enhancing the overall performance of the system.

[0575] The electric drive arrangement may further comprise a freewheel being connected with the spindle and with the sleeve.

[0576] The freewheel transmits force only in one rotational direction from the output shaft to the spindle. If the spindle rotates faster than the output shaft the freewheel allows this by decoupling the output shaft from the spindle .

[0577] The freewheel mechanism ensures that force is transmitted from the output shaft and / or the sleeve to the spindle only in the desired rotational direction, providing controlled operation and preventing potential damage from reverse torque.

[0578] By allowing the spindle to rotate faster than the sleeve without engaging the latter, the freewheel decouples the two components, which can lead to smoother operation and reduced mechanical stress on the electric motor during high spindle speeds.

[0579] The electric drive arrangement may further comprise a further sleeve being rotationally fixed to the sleeve and to the freewheel. The inclusion of a further sleeve that is rotationally fixed to both the sleeve and the freewheel ensures a robust and reliable transmission of torque, enhancing the overall mechanical integrity of the drive arrangement.

[0580] This configuration minimizes the number of moving parts, thereby reducing the potential for mechanical failure and simplifying maintenance requirements.

[0581] In a development, the arrangement further comprises a further sleeve having a plurality of inside teeth engaging with the sleeve.

[0582] The further sleeve with a plurality of inside teeth engaging with the sleeve provides a secure and precise connection, which improves the transfer of rotational force and reduces slippage between components.

[0583] The interlocking teeth design allows for the distribution of load across multiple contact points, leading to improved wear characteristics and a longer service life for the drive arrangement. Especially, the further teeth may contact the sleeve from radially outwards.

[0584] In a development, the arrangement further comprises an electric motor, the pin ring gear, the freewheel, the further sleeve, and / or the spindle being arranged with a common symmetry axis.

[0585] This is especially to make it easier to fabricate.

[0586] Centralizing the electric motor, pin ring gear, freewheel, further sleeve, and / or spindle along a common symmetry axis results in a more compact and balanced design, which can contribute to improved vehicle handling and stability.

[0587] The aligned configuration simplifies the assembly process, potentially reducing manufacturing costs and facilitating easier integration into various vehicle platforms.

[0588] The disclosure relates further to an electric drive arrangement, the electric drive arrangement comprising: - a spindle

[0589] - an electric motor having an output shaft

[0590] - a pin ring gear being driven by the output shaft and comprising an output wheel especially as disclosed herein,

[0591] - a freewheel being connected with the spindle and with the sleeve, and

[0592] - a further sleeve being rotationally fixed to the sleeve and to the freewheel,

[0593] - wherein the sleeve has a plurality of inside teeth engaging with the sleeve.

[0594] The integration of an output wheel as disclosed herein with the pin ring gear driven by the electric motor's output shaft ensures that the drive arrangement benefits from the optimized performance characteristics of the output wheel, such as enhanced torque delivery or reduced noise.

[0595] The connection of the freewheel with both the spindle and the sleeve, along with the further sleeve being rotationally fixed, creates a seamless power flow from the motor to the drive mechanism, improving efficiency and responsiveness of the electric drive arrangement. Especially, the freewheel may be connected to the sleeve via the further sleeve.

[0596] The disclosure relates also to an electric bicycle comprising an electric drive arrangement especially as disclosed herein.

[0597] Incorporating the electric drive arrangement as described herein into an electric bicycle provides the end product with a highly integrated and efficient propulsion system, which can lead to longer battery life and extended range for the user.

[0598] The use of a freewheel mechanism in the electric bicycle's drive arrangement allows for coasting capabilities when power is not being applied, thereby reducing drag and contributing to a more natural riding experience.

[0599] There is disclosed an output wheel (the term output wheel is used herein especially to refer to a gearwheel for the pin ring gear of an electric drive arrangement) for a pin ring gear (the term pin ring gear is used herein to refer to the pin ring gear of an electric drive arrangement) of an electric drive arrangement (a drive arrangement for a pin ring gear of an electric drive arrangement), the output wheel comprising:

[0600] - a gearwheel (the term gearwheel is used herein to refer to a component of the output wheel which comprises a gearwheel and a sleeve) and

[0601] - a sleeve (the term sleeve may be used herein to refer to a cylindrical component)

[0602] - wherein the gearwheel and the sleeve are embodied as a one-piece component (the term one-piece component herein refers to a component that is made of two or more parts) such that the gearwheel extends radially outward from the sleeve and

[0603] - wherein the sleeve provides a plain bearing (the term plain bearing is used herein to refer to a component which provides a plain bearing for the spindle inside the sleeve) for a spindle (the term spindle is used herein to refer to a spindle on which a force may be applied to rotate it) inside the sleeve

[0604] This eliminates an interface (the term interface is used herein to refer to an interface between the gearwheel and the sleeve) between the gearwheel and the sleeve thus reducing radial extension (the term radial extension is understood to mean an extension of the radii of the gearwheel and the sleeve from the one-piece component) and simplifying coaxial alignment (the term coaxial alignment is understood to refer to an alignment of the gearwheel and the sleeve) and manufacturing (the assembly of the output wheel with the electric drive arrangement)].

[0605] In a development, the wheel (in the present disclosure, the term wheel is used to refer to a gearwheel and a sleeve) further comprises a gearwheel and the sleeve being made of the same material (the material of the wheel and the sleeve).

[0606] In a development, the wheel further comprises a gearwheel and the sleeve being made of Polyether Ether Ketone (a material which is a copolymer of polyether and ketone) (PEEK (polyether ether ketone (peek))).

[0607] This helps reducing weight (a reduction of the weight of the output wheel), increasing wear resistance (the fact that the material of the sleeve is harder than the material of the gearwheel), low coefficient of friction (the term low coefficient of friction refers to a coefficient of friction in a development, wherein the wheel further comprises a gearwheel and a sleeve) with hardened steel (the friction between the pin ring gear and the hardened steel of the spindle)].

[0608] In a development, the wheel further comprises a gearwheel and the sleeve forming an L- shape (a shape of a cross-section of the wheel, widening in radial direction from a middle part towards a radial outer part) in a part of a cross-section (the term cross-section herein refers to a cross-section of the wheel) on one side of a symmetry axis (the axis of rotation of the output wheel).

[0609] In a development, the wheel further comprises a gearwheel seen in a cross-section, widening in radial direction (the term radial direction is understood to mean a direction perpendicular to the longitudinal extension of the sleeve in a development) from a middle (in the present disclosure, the term middle is used to refer to a middle part of the gearwheel, the term outer is used to refer to an outer part of the gearwheel) part towards a radial outer (the term radial outer is understood to mean a direction perpendicular to the longitudinal extension of the sleeve in a development) part.

[0610] In a development, the wheel further comprises that the gearwheel seen in a cross-section, widens in radial direction from a middle part towards the sleeve

[0611] The middle part can being made with less material, reducing weight (the weight of the wheel, the spindle and / or the pinion)].

[0612] In a development, the wheel further comprises a gearwheel extending perpendicular to a longitudinal extension (the term longitudinal extension of the sleeve may be seen parallel to a symmetry axis) of the sleeve.

[0613] Electric drive arrangement, the electric drive arrangement comprising:

[0614] - a spindle,

[0615] - an electric motor (a motor that may assist a driver) having an output shaft and

[0616] - a pin ring gear being driven by the output shaft and comprising an output wheel as disclosed herein. The spindle may be made of hardened steel (e.g. a steel with a hardness of at least hrc 40)].

[0617] The electric drive arrangement may further comprise a freewheel (the term freewheel is understood to refer to a component transmitting force in only one rotational direction) being connected with the spindle and with the sleeve.

[0618] The freewheel may transmit force only in one rotational direction (the term rotational direction as used herein is intended to refer to a rotational direction from the sleeve to the spindle) from the sleeve to the spindle If the spindle rotates faster than the sleeve the freewheel allows this by decoupling the sleeve from the spindle.

[0619] In a development, the arrangement further comprises an electric motor, the pin ring gear, the freewheel, the further sleeve, and / or the spindle being arranged with a common symmetry axis (especially a symmetry axis of the pin ring gear).

[0620] This makes it especially easier to fabricate.

[0621] Electric bicycle (a bicycle that is driven by an electric motor) may comprise an electric drive arrangement as disclosed herein.

[0622] In an embodiment, the output wheel comprises a gearwheel and a sleeve made of Polyether Ether Ketone (PEEK) and extends perpendicular to a longitudinal extension of the sleeve.

[0623] The advantageous effects of this combination include reduced weight, increased wear resistance, and simplified manufacturing due to the one-piece component design.

[0624] In an embodiment, the output wheel comprises a gearwheel and a sleeve made of PEEK, providing a plain bearing for a spindle, and is connected to a further sleeve rotationally fixed to the freewheel, with all components arranged with a common symmetry axis. This combination facilitates ease of fabrication and ensures precise alignment due to the common symmetry axis, while also offering the benefits of PEEK material.

[0625] In an embodiment, the electric drive arrangement comprises a spindle, an electric motor with an output shaft, a pin ring gear with an output wheel, a freewheel connected with the spindle and the sleeve, and a further sleeve with a plurality of inside teeth engaging with the sleeve.

[0626] The advantageous effects of this combination include efficient force transmission in one rotational direction and decoupling capability when the spindle rotates faster than the sleeve, enhancing the overall performance of the electric drive arrangement.

[0627] There is disclosed a gearwheel design with Integrated Plain Bearing utilizing hardened Steel and PEEK for Improved Drivetrain Performance

[0628] Background:

[0629] The drivetrain of an e-bike motor includes gearwheels and plain bearings, which operate under high stress and wear due to the continuous interaction of moving parts. Conventional designs rely on separate gearwheels, plain bearings, and shafts that require precise coaxial alignment, leading to increased complexity, higher manufacturing costs, and susceptibility to misalignment. These challenges are particularly significant in compact drivetrain systems such as those in e-bikes, where space constraints and weight considerations are critical.

[0630] The existing drivetrain designs face the following issues:

[0631] 1. Wear and Friction:

[0632] - Traditional materials for plain bearings (e.g., metal-on-metal designs) result in high friction and wear.

[0633] - Surfaces and cylindrical shapes require precise machining, increasing production costs.

[0634] 2. Coaxial Alignment Errors: - The previous design involved three components (gearwheel, plain bearing, and shaft), each needing precise coaxial alignment. Misalignment led to performance inefficiencies and higher failure rates.

[0635] 3. Space Constraints:

[0636] Adding interfaces between components increases the drivetrain’s outer diameter, limiting the design’s suitability for compact applications like e-bikes.

[0637] 4. Manufacturability:

[0638] - Complex assemblies and multiple interfaces make manufacturing expensive and error- prone.

[0639] Technical Details:

[0640] The new gearwheel design integrates the plain bearing directly into the gearwheel using a combination of hardened steel and PEEK.

[0641] 1. Material Pairing:

[0642] - Hardened Steel Shaft: Provides durability and strength, suitable for high-stress environments.

[0643] - PEEK Gearwheel: Offers excellent wear resistance, low friction, and is lightweight. The PEEK component acts as both the gearwheel and the plain bearing surface..

[0644] 2. Elimination of Interfaces:

[0645] - The gearwheel and plain bearing are combined into a single component, reducing the number of coaxial elements from three to two.

[0646] - This eliminates an interface, minimizing coaxial alignment errors and simplifying assembly.

[0647] 3. Compact Design:

[0648] - The new design adds only 2 millimeters to the outer diameter of the gearwheel, significantly saving radial installation space. 4. Weight Reduction:

[0649] - By integrating the plain bearing into the gearwheel and using lightweight PEEK material, the overall weight of the assembly is reduced.

[0650] Distinguishing Features:

[0651] 1. Combination of Hardened Steel and PEEK:

[0652] - Low coefficient of friction.

[0653] - High durability and wear resistance.

[0654] 2. Reduction of Components:

[0655] - Two components instead of three (gearwheel and plain bearing combined).

[0656] 3. Minimized Coaxial Errors:

[0657] - Direct integration of the plain bearing into the gearwheel eliminates one coaxial interface.

[0658] - Reduction of coaxial components from three to two.

[0659] 4. Space and Weight Savings:

[0660] - Adds only 2 millimeters to the outer diameter, saving radial installation space.

[0661] - Lighter overall design compared to traditional setups.

[0662] The Problem It Solves:

[0663] 1. Wear and Friction:

[0664] - Reduces wear and friction between drivetrain components, extending the motor’s lifespan.

[0665] 2. Manufacturability:

[0666] - Simplifies manufacturing by reducing the number of components and interfaces.

[0667] 3. Alignment Issues:

[0668] - Eliminates an interface, minimizing coaxial alignment errors and improving reliability. 4. Space and Weight Constraints:

[0669] - Reduces installation space and weight, making it ideal for compact e-bike designs.

[0670] Advantages:

[0671] 1. Improved Durability:

[0672] - Hardened steel and PEEK offer exceptional resistance to wear and friction.

[0673] 2. Simplified Manufacturing:

[0674] - Fewer components and interfaces mean reduced machining and assembly costs.

[0675] 3. Compact and Lightweight:

[0676] - Saves 2 millimeters of installation space and reduces weight.

[0677] 4. Enhanced Reliability:

[0678] - Coaxial alignment errors are reduced, improving overall drivetrain performance.

[0679] 5. Cost-Effective Manufacturing:

[0680] - Minimizes precision machining requirements for plain bearings.

[0681] Unique Aspects:

[0682] Integration of plain bearing functionality directly into the gearwheel.

[0683] Use of PEEK, a high-performance engineering plastic, in a critical drivetrain component.

[0684] Elimination of a coaxial interface, reducing alignment errors.

[0685] Space-efficient design suitable for compact applications like e-bikes.

[0686] Potential Applications and Use Cases:

[0687] 1. E-Bike Motors:

[0688] - Primary application for compact, efficient motor systems. 2. Electric Scooters:

[0689] - Compact drivetrains requiring lightweight and durable components.

[0690] 3. Automotive Components:

[0691] - Small-scale transmission systems in lightweight electric vehicles.

[0692] Technical Details:

[0693] 1. Overview of the Original Design Problem:

[0694] - The original design included a bottom bracket shaft connected to a freewheel via toothing, creating a plain bearing between two components.

[0695] - High demands on surfaces and cylindrical precision increased manufacturing costs.

[0696] - The plain bearing experienced wear and tear when the motor was disengaged (e.g., pedaling over 25 km / h).

[0697] 2. Innovative Design Solution:

[0698] - Integration of Components:

[0699] - The gearwheel now incorporates the plain bearing functionality, combining it with the gear itself.

[0700] - Material choice of hardened steel (shaft) and PEEK (gearwheel) provides a durable, low-friction, wear-resistant interface.

[0701] - Reduction of Interfaces:

[0702] - The interface between the plain bearing and the gearwheel was eliminated, reducing coaxial alignment errors.

[0703] - A transition from three components requiring coaxiality to only two.

[0704] 3. Advantages Highlighted:

[0705] Precision and Efficiency:

[0706] - Elimination of coaxial alignment errors leads to improved drivetrain reliability.

[0707] Compact and Lightweight:

[0708] - The design increases the outer diameter by only 2 millimeters. - Saves radial installation space and reduces overall system weight.

[0709] Manufacturability:

[0710] - Simplifies manufacturing processes, reducing costs associated with machining precision surfaces and cylindrical components.

[0711] 4. Material Properties:

[0712] PEEK:

[0713] - Exceptional wear resistance.

[0714] - Low coefficient of friction when paired with hardened steel.

[0715] Hardened Steel:

[0716] - Provides strength and durability under high-stress environments.

[0717] 5. Potential Applications:

[0718] - The discussion ties the design improvements to their unique selling proposition (USP), suggesting the solution has strong commercial potential for applications like e-bike motors or other compact drivetrain systems.

[0719] Potential Aspects:

[0720] 1. A gearwheel design incorporating a hardened steel shaft and a PEEK plain bearing to reduce wear and friction.

[0721] 2. A drivetrain assembly that integrates the plain bearing into the gearwheel, reducing the number of coaxial components.

[0722] 3. A compact and lightweight gearwheel design with a radial installation space reduction of 2 millimeters. 4. A method for reducing coaxial alignment errors in drivetrain assemblies by combining the gearwheel and plain bearing into a single component.

[0723] In further aspects that refer to elements of the freewheel design based on GM standards, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0724] These aspects generally relate to freewheel mechanisms, and more particularly to freewheels utilized in electric drive arrangements. These aspects also relates to an electric drive arrangement and to a method.

[0725] These aspects address the problem of inefficient power transmission and engagement in electric drive arrangements.

[0726] These aspects provide solutions for a freewheel mechanism that allows for effective engagement and disengagement between a cage and an outer ring, enabling the transmission of rotational movement in one direction while preventing it in the opposite direction.

[0727] This can be achieved through the use of rotatable connecting elements that engage the outer ring by friction when the cage rotates in the designated direction, while also incorporating a biasing spring to maintain the connecting elements in a resting position. The design facilitates a compact arrangement that integrates with an electric motor, gear, and spindle, ensuring reliable operation in various applications without the need for complex mechanical linkages.

[0728] Embodiments of the application are associated with various advantages and / or technical effects.

[0729] There is disclosed a freewheel for an electric drive arrangement, comprising

[0730] - a cage having a circular shape,

[0731] - several connecting elements, and

[0732] - an outer ring, - wherein the connecting elements are mounted in the cage to be rotatable, and to engage the outer ring if the cage rotates in a first direction relative to the outer ring, and to not engage the outer ring if the cage rotates in a second direction relative to the outer ring.

[0733] The first direction is especially opposite to the second direction.

[0734] The rotatable mounting of the connecting elements within the cage allows for a smooth transition between engagement and disengagement with the outer ring, thereby reducing mechanical stress and wear on the components.

[0735] The selective engagement feature of the connecting elements provides a unidirectional drive capability, which is essential for applications requiring a freewheel mechanism, such as in electric vehicle drivetrains or electric bicycles.

[0736] The design provides the advantage of conductive efficiency, allowing for effective transmission of rotational movement between the cage and the outer ring in the freewheel mechanism.

[0737] The arrangement offers the advantage of flexibility, enabling the electric drive system to adapt to various operational conditions and requirements.

[0738] The configuration presents the advantage of versatility, allowing the electric drive arrangement to be utilized in a wide range of applications and environments.

[0739] The construction ensures the advantage of manufacturability, facilitating easier production processes and reducing manufacturing costs for the components involved.

[0740] The integration of components provides the advantage of synergical performance, enhancing the overall efficiency and functionality of the electric drive arrangement as a cohesive system.

[0741] In a development, the freewheel further comprises a cage being embodied as an inner wheel. The embodiment of the cage as an inner wheel simplifies the overall design of the freewheel, potentially reducing manufacturing costs and assembly complexity.

[0742] Integrating the cage and inner wheel into a single component can lead to a more compact and lightweight freewheel assembly, which is beneficial for electric drive arrangements where space and weight are critical factors.

[0743] In a development, the freewheel further comprises an inner wheel being embodied with a first wheel part and a second wheel part, wherein the connecting elements may be arranged between the first wheel part and the second wheel part.

[0744] The arrangement of connecting elements between the first and second wheel parts ensures that the forces are evenly distributed across the freewheel mechanism, enhancing its durability and load-bearing capacity.

[0745] The division of the inner wheel into two parts allows for easier maintenance and replacement of individual components, which can extend the service life of the freewheel and reduce downtime for repairs.

[0746] In a development, the freewheel further comprises, if the cage rotates in the first direction relative to the outer ring, the connecting elements engaging the outer ring by friction in order to transmit rotational movement between the outer ring and the cage.

[0747] The frictional engagement between the connecting elements and the outer ring when rotating in the first direction ensures a secure transmission of rotational movement, providing reliable operation under varying load conditions.

[0748] The use of friction for engagement allows for a smoother and quieter operation of the freewheel, which is particularly advantageous in electric drive arrangements where noise reduction is desirable. In a development, the freewheel further comprises connecting elements having a bone shape or a hammer shape.

[0749] This may mean one or two widened end parts, and / or a smaller part where the connecting element is connected to the cage.

[0750] The bone or hammer shape of the connecting elements provides a larger surface area for engagement with the outer ring, which can improve the torque transmission efficiency and reduce slippage.

[0751] The specific shape of the connecting elements, with one or two widened end parts, allows for a more robust connection to the cage, which can enhance the mechanical integrity of the freewheel under high-stress conditions.

[0752] The freewheel may comprise a spring, biasing the connecting elements in a resting position.

[0753] The inclusion of a spring that biases the connecting elements in a resting position ensures a reliable engagement and disengagement of the freewheel mechanism, thereby enhancing the operational consistency of the device.

[0754] The spring mechanism contributes to a reduction in mechanical wear and tear on the connecting elements, leading to an extended service life of the freewheel and reduced maintenance requirements.

[0755] There is also disclosed an electric drive arrangement, comprising

[0756] - a freewheel as disclosed herein,

[0757] - an electric motor,

[0758] - a gear, and

[0759] - a spindle,

[0760] - wherein the electric motor is adapted to drive the gear,

[0761] - wherein the gear has an output wheel, - wherein the output wheel is torque proof connected with the freewheel to drive the outer ring of the freewheel,

[0762] - wherein the cage of the freewheel is torque proof connected with the spindle.

[0763] This can especially allow that the spindle rotates faster than the output wheel.

[0764] The integration of the freewheel with an electric motor and gear system allows for precise control of mechanical output, enabling the spindle to rotate at a higher speed than the output wheel, which can be beneficial for applications requiring speed amplification.

[0765] The torque-proof connection between the output wheel and the freewheel ensures efficient transmission of power from the electric motor to the spindle, minimizing energy losses and improving the overall efficiency of the drive arrangement.

[0766] In a development, the arrangement further comprises an output wheel being torque proof connected with a sleeve.

[0767] The torque-proof connection of the output wheel with a sleeve ensures a secure and stable transfer of rotational force, which is critical for maintaining the integrity of the mechanical system under varying load conditions.

[0768] This configuration allows for a modular assembly, facilitating easier replacement or maintenance of individual components without the need for disassembling the entire drive arrangement.

[0769] In a development, the arrangement further comprises a sleeve being directly connected with a further sleeve, and wherein the further sleeve may be directly connected with the outer ring of the freewheel.

[0770] The direct connection between the sleeves and the outer ring of the freewheel allows for a compact and streamlined design, reducing the overall size and complexity of the drive arrangement. By directly connecting the sleeves, the arrangement minimizes the number of moving parts, which can reduce potential points of failure and enhance the reliability of the system.

[0771] In a development, the arrangement further comprises a sleeve comprising a plain bearing holding the spindle.

[0772] The inclusion of a plain bearing within the sleeve that holds the spindle provides a low- friction support, which can reduce energy consumption and heat generation during operation.

[0773] The plain bearing facilitates smooth rotation of the spindle, contributing to a quieter operation and improved performance characteristics of the electric drive arrangement.

[0774] There is also disclosed an electric drive arrangement, comprising

[0775] - a freewheel as disclosed herein,

[0776] - an electric motor,

[0777] - a gear, and

[0778] - a spindle,

[0779] - wherein the electric motor is adapted to drive the gear,

[0780] - wherein the gear has an output wheel,

[0781] - wherein the output wheel is torque proof connected with the freewheel to drive the outer ring of the freewheel,

[0782] - wherein the cage of the freewheel is torque proof connected with the spindle,

[0783] - wherein the output wheel is torque proof connected with a sleeve,

[0784] - wherein the sleeve is directly connected with a further sleeve,

[0785] - wherein the further sleeve is directly connected with the outer ring of the freewheel, and

[0786] - wherein the sleeve comprises a plain bearing holding the spindle.

[0787] The integration of a freewheel with a torque-proof connection to the output wheel and the spindle ensures efficient transmission of power from the electric motor to the spindle, minimizing energy loss and enhancing the overall performance of the drive arrangement. The use of a plain bearing within the sleeve to hold the spindle provides a low-friction support mechanism, which reduces wear and extends the service life of the electric drive arrangement.

[0788] The direct connection between the sleeves and the outer ring of the freewheel simplifies the assembly process, leading to a more compact and robust design that can be easily integrated into various applications.

[0789] There is also disclosed a method of fabricating an electric drive arrangement, the method comprising the following steps:

[0790] - providing a spindle, an electric motor, a gear with an output wheel and a sleeve being torque proof connector to the output wheel, and a freewheel as disclosed herein,

[0791] - placing the spindle partially inside a plain bearing provided inside the sleeve,

[0792] - putting the freewheel around the spindle,

[0793] - securing the cage torque proof to the spindle,

[0794] - securing the outer ring torque proof to the gear, and

[0795] - securing the gear to the electric motor.

[0796] The methodical approach to assembling the electric drive arrangement ensures precise alignment of components, which contributes to smooth operation and reduced vibration during use.

[0797] By securing the cage torque-proof to the spindle and the outer ring torque-proof to the gear, the method guarantees that the freewheel mechanism will function reliably, providing a fail-safe operation in one direction while allowing free rotation in the other.

[0798] The step of securing the gear to the electric motor ensures that all preceding components are correctly positioned, which facilitates a straightforward and error-free installation process.

[0799] In a development, the method further comprises a surface of the spindle being machined to provide a dedicated contact surface radially inwards to the sleeve. Machining a dedicated contact surface on the spindle provides an optimized interface for the sleeve, which can enhance load distribution and reduce stress concentrations, leading to improved durability of the electric drive arrangement.

[0800] The creation of a specific machined surface on the spindle allows for a more precise fit with the sleeve, which can improve the concentricity and alignment of the spindle within the electric drive arrangement, resulting in smoother operation.

[0801] In a development, the method further comprises a surface of the spindle being not machined to provide a dedicated contact surface radially inwards to the freewheel.

[0802] By not machining a dedicated contact surface on the spindle for the freewheel, manufacturing complexity and costs can be reduced without compromising the functionality of the freewheel mechanism.

[0803] The un-machined surface of the spindle may provide a more versatile interface for different types of freewheels, allowing for greater flexibility in the design and adaptation of the electric drive arrangement to various applications.

[0804] The electric drive arrangement may especially be fabricated as disclosed herein.

[0805] Fabricating the electric drive arrangement according to the variants disclosed herein ensures a standardized process that can lead to consistent quality and performance across multiple units, which is beneficial for mass production.

[0806] The adherence to a defined fabrication method allows for the potential automation of the assembly process, which can significantly increase production efficiency and reduce labor costs.

[0807] An "electric drive arrangement" designates a drive arrangement that is driven by an electric motor. A "gearwheel" may designate a wheel that is connected to the output of the electric motor and that is connected to the freewheel.

[0808] A "middle part" designates the part of the connecting element that is connected to the cage.

[0809] The term "plain bearing" is used herein to refer to a bearing having a cylindrical shape, and which may be rotated in any direction.

[0810] The term "electrical motor" is used herein to refer to a gear-driven electric motor, wherein the gear-driven electric motor may have a gear drive arrangement.

[0811] An "output shaft" designates s shaft of the gear, where force transmitted through the gear comes out.

[0812] The term "freewheel" is used herein to refer to a rotating arrangement for an electric drive arrangement, which includes a cage having a circular shape and several connecting elements.

[0813] The term "cage" is understood to refer to a structure having a circular shape, in which the connecting elements are mounted.

[0814] The term "first wheel part" may refer to a first wheel part, and the term "second wheel part" may refer to a second wheel part.

[0815] The term "connecting elements" may refer to a plurality of elements, which can be connected by friction to an outer ring.

[0816] An "Electric drive arrangement" designates a drive arrangement that is driven by an electric motor.

[0817] The term "outer ring" is used herein to refer to the outer ring of the freewheel. The term "fist direction" refers to the first direction relative to the outer ring.

[0818] A "second direction" designates the direction in which the cage rotates relative to the outer ring.

[0819] The term "inner wheel" is used herein to refer to a wheel having a circular shape, wherein the connecting elements are arranged between the outer and inner wheels.

[0820] A "circular shape" designates a shape that is circular or elliptical.

[0821] A "fist direction" designates the direction in which the cage rotates relative to the outer ring.

[0822] The term "rotational movement" may refer to a rotation of the cage, which rotates in one direction relative to the outer ring.

[0823] A "hammer shape" designates a shape with a widened end part and a smaller part where the connecting element is connected to the cage.

[0824] A "resting position" designates a position in which the connecting elements are not engaged with the outer ring.

[0825] There is disclosed a freewheel (the term freewheel is understood to refer to a wheel having a circular shape, wherein the connecting elements are arranged in a cage) for an electric drive arrangement (the combination of the freewheel and the electric motor, the gear and the output wheel), comprising

[0826] - a cage (the term cage is understood to refer to a structure having a circular shape, - several connecting elements and - an outer ring) having a circular shape (a shape that is circular or oval, but not necessarily a shape that is circular or oval],

[0827] - several connecting elements (the term connecting elements is understood to mean, in particular, a plurality of connecting elements), and

[0828] - an outer ring (the term outer ring is used herein to refer to the outer ring, unless otherwise indicated), - wherein the connecting elements are mounted in the cage to be rotatable, and to engage the outer ring if the cage rotates in a first direction (the direction of rotation of the spindle) relative to the outer ring, and to not engage the outer ring if the cage rotates in a second direction (the term first direction may refer to a first direction relative to the outer ring, and second direction may refer to a second direction relative to the outer ring) relative to the outer ring.

[0829] The fist direction (the direction of rotation of the freewheel relative to the spindle is opposite to the second direction.

[0830] In a development, the freewheel further comprises a cage being embodied as an inner wheel (the term inner wheel is understood to refer to a wheel having a cylindrical shape, wherein the connecting elements are mounted in the cage).

[0831] In a development, the freewheel further comprises an inner wheel being embodied with a first wheel (the term first wheel is understood to refer to the first wheel, whereas the term second wheel is understood to refer to the second wheel) part and a second wheel (the term first wheel is understood to refer to the first wheel part, whereas the term second wheel is understood to refer to the second wheel) part, wherein the connecting elements are arranged between the first wheel part and the second wheel part.

[0832] In a development, the freewheel further comprises, if the cage rotates in the first direction relative to the outer ring, the connecting elements engaging the outer ring by friction in order to transmit rotational movement between the outer wheel land the cage.

[0833] In a development, the freewheel further comprises connecting elements having a bone shape (the term bone shape is understood to refer to a bone shape) or a hammer shape.

[0834] The freewheel may comprise a spring (a spring element, which is not necessarily a spring element in the sense of the present application), biasing the connecting elements in a resting position.

[0835] There is also disclosed an electric drive arrangement, comprising - a freewheel as disclosed herein,

[0836] - an electric motor,

[0837] - a gear, and

[0838] - a spindle,

[0839] - wherein the electric motor is adapted to drive the gear,

[0840] - wherein the gear has an output wheel,

[0841] - wherein the output wheel is torque proof connected with the freewheel to drive the outer ring of the freewheel,

[0842] - wherein the cage of the freewheel is torque proof connected with the spindle.

[0843] This can allow that the spindle rotates faster than the output wheel.

[0844] In a development, the arrangement further comprises an output wheel being torque proof connected with a sleeve (the term sleeve is understood to refer to a tube having a cylindrical shape, which may be directly connected with the outer ring of the freewheel).

[0845] In a development, the arrangement further comprises a sleeve comprising a plain bearing (in the present application, the term plain bearing is understood to refer to a bearing having a cylindrical shape) holding the spindle.

[0846] There is also disclosed a method of fabricating an electric drive arrangement, the method comprising the following steps:

[0847] - providing a spindle, an electric motor, a gear with an output wheel and a sleeve being torque proof connected to the output wheel, and a freewheel as disclosed herein,

[0848] - placing the spindle partially inside a plain bearing provided inside the sleeve,

[0849] - putting the freewheel around the spindle,

[0850] - securing the cage torque proof to the spindle,

[0851] - securing the outer ring torque proof to the gear, and

[0852] - securing the gear to the electric motor.

[0853] In a development, the method further comprises a surface of the spindle being machined to provide a dedicated contact surface radially inwards to the sleeve. Freewheels are indispensable components in drivetrain systems, particularly for applications like e-bikes and electric scooters. They enable unidirectional motion, allowing motors or pedals to disengage during coasting, while maintaining power transfer when needed. Conventional freewheel designs, often based on rolling-element mechanisms, struggle with challenges like handling high torque, mitigating misalignments, and resisting wear over time. These limitations necessitate innovations to improve the durability, reliability, and manufacturability of freewheels, especially for high- performance applications requiring compact designs.

[0854] Concept 6: Freewheel design based on GM standards.

[0855] Background:

[0856] Freewheels are indispensable components in drivetrain systems, particularly for applications like e-bikes and electric scooters. They enable unidirectional motion, allowing motors or pedals to disengage during coasting, while maintaining power transfer when needed. Conventional freewheel designs, often based on rolling-element mechanisms, struggle with challenges like handling high torque, mitigating misalignments, and resisting wear over time. These limitations necessitate innovations to improve the durability, reliability, and manufacturability of freewheels, especially for high- performance applications requiring compact designs.

[0857] Problem Statement:

[0858] Traditional freewheels face several critical challenges:

[0859] 1. High Torque Demand:

[0860] - Many existing designs fail to reliably handle high torque loads, leading to slippage or accelerated wear under heavy-duty applications.

[0861] 2. Misalignment Issues:

[0862] - Axial and coaxial misalignments, common in real-world operating conditions, can degrade performance and cause premature failure. 3. Complex and Expensive Manufacturing:

[0863] - Rolling-element freewheels require precision machining and assembly, increasing manufacturing costs and complexity.

[0864] 4. Space Constraints:

[0865] - In compact drivetrain systems like e-bikes, freewheels often compete for limited installation space, necessitating smaller yet more robust designs.

[0866] Technical Details

[0867] 1. Friction-Based Clamping Mechanism:

[0868] - Utilizes friction and clamping elements, eliminating the need for rolling elements (e.g., races and rollers).

[0869] - Incorporates springs to maintain consistent tension, ensuring smooth engagement and disengagement.

[0870] - Cage structure enhances stability and facilitates efficient power transmission.

[0871] 2. High Torque Capacity:

[0872] - Capable of withstanding up to 80 Nm of torque under optimal conditions and 70 Nm with minor misalignments.

[0873] - Designed to handle the demands of high-performance drivetrain systems.

[0874] 3. Misalignment Tolerance:

[0875] - The freewheel accommodates significant axial and coaxial misalignments, ensuring reliable performance in less-than-ideal alignment conditions.

[0876] - Reduces wear caused by misaligned components, extending operational lifespan.

[0877] 4. Structural Durability:

[0878] - Key components, including detents, clamping elements, and springs, are riveted for enhanced durability and to prevent loosening during operation.

[0879] 5. Compact and Space- Efficient Design: - Optimized for compact systems, minimizing installation space while retaining robustness and functionality.

[0880] Distinguishing Features:

[0881] 1. Friction-Based Clamping Mechanism:

[0882] - Eliminates the need for rolling elements, offering a simplified and durable solution.

[0883] 2. Tolerance to Misalignment:

[0884] - Unlike traditional designs prone to misalignment-related failures, it handles both axial and coaxial misalignments without affecting performance or introducing significant wear.

[0885] 3. Customizable Torque Capabilities:

[0886] - Capable of handling high loads up to 80 Nm, suitable for high-performance e-bike motors.

[0887] 4. Compact and Robust Design:

[0888] Ideal for compact motor systems where space and reliability are critical. Ideal for applications with limited space, such as lightweight electric vehicles and compact robotics.

[0889] The Problem It Solves:

[0890] 1. Improves Load Handling:

[0891] - Provides reliable performance under significant torque, addressing the limitations of traditional freewheels.

[0892] 2. Enhances Alignment Flexibility:

[0893] - Mitigates performance degradation and wear caused by misalignments, ensuring smooth operation and improving durability.

[0894] 3. Simplified Manufacturing: - The friction-based design eliminates the complexity of rolling elements like races and rollers.

[0895] 4. Enables Versatile Applications:

[0896] - Tailored to meet the needs of compact, high-performance drivetrain systems

[0897] Advantages:

[0898] 1. Proven Reliability:

[0899] - proven design foundation coupled with robust clamping elements ensures long-lasting performance.

[0900] 2. High Torque Capacity:

[0901] - Supports loads up to 80 Nm, ideal for high-performance applications.

[0902] 3. Durable and Long-Lasting:

[0903] - Riveted construction and robust clamping elements reduce wear and extend service life.

[0904] 4. Compact and Space-Efficient:

[0905] - Suitable for e-bike motors with limited installation space.

[0906] 5. Cost-Effective:

[0907] - Friction-based design is simpler and less expensive to manufacture compared to roller-based freewheels.

[0908] Aspects:

[0909] - Integration of Friction-Based Clamping: Avoids the complexity of rolling elements while maintaining secure engagement.

[0910] - Enhanced Misalignment Tolerance: Reduces wear and ensures functionality under real-world alignment conditions.

[0911] - Custom Torque Capabilities: Specifically designed to manage high torque loads, exceeding the capabilities of standard freewheel designs. Potential Applications and Use Cases

[0912] 1. E-Bike Motors:

[0913] - Ensures smooth power transfer, reliable disengagement during coasting, and tolerance to misalignments.

[0914] 2. Electric Scooters:

[0915] - Ideal for compact drivetrains requiring high torque capacity and durability.

[0916] 3. Automotive Applications:

[0917] - Can be adapted for small-scale vehicles or other systems requiring reliable unidirectional motion.

[0918] 4. Robotic Applications:

[0919] - Robots designed for energy conservation (e.g., warehouse robots or exoskeletons) could benefit significantly from this friction-based freewheel which allows motors to disengage when not actively driving the system, minimizing energy consumption and wear.

[0920] Potential Aspects:

[0921] 1. A freewheel design, incorporating a friction-based clamping mechanism with springs and / or detents.

[0922] 2. A freewheel system capable of tolerating axial and coaxial misalignments while maintaining reliable performance.

[0923] 3. A high-torque freewheel capable of handling up to 80 Nm of torque under optimal conditions.

[0924] 4. A compact freewheel design featuring riveted clamping elements and springs for durability and reduced wear. In further aspects that refer to elements of the sensor device housing and TPU plug, various advantageous effects can be seen. These elements can be combined with the other elements in the present application as described above and below.

[0925] These aspects generally relate to measurement systems, and more particularly to a measurement system for a spindle.

[0926] These aspects address the problem of accurately measuring forces acting on a spindle in dynamic environments.

[0927] The application provides solutions for the challenges associated with force measurement in rotating systems, where traditional measurement techniques may be hindered by the need for compactness, structural integrity, and the ability to withstand varying operational conditions.

[0928] The proposed measurement system incorporates a meander form structure that enhances sensitivity to strain while maintaining robustness, and integrates strain gauges positioned strategically to capture force data effectively. Additionally, the design includes features such as rotational symmetry, grooves for environmental protection, and a bearing arrangement that decouples axial movement, thereby ensuring reliable performance in applications involving electric drive arrangements and other mechanical systems.

[0929] Embodiments of the application are associated with various advantages and / or technical effects.

[0930] There is disclosed a measurement system for measuring a force acting on a spindle the measurement system comprising

[0931] - a structure, the structure having a meander form in a cross-section, and

[0932] - at least one strain gauge

[0933] - wherein the meander form comprises at least a first surface and a second surface extending perpendicular to a central axis, - wherein the meander form comprises an intermediate part between the first surface and the second surface, the intermediate part having a U-shape, and

[0934] - wherein the strain gauge is positioned on the first surface or the second surface.

[0935] The meander form with perpendicular surfaces and a U-shaped intermediate part provides enhanced sensitivity to strain, as the geometry is optimized to concentrate stress in specific areas, allowing for more accurate force measurements.

[0936] Positioning the strain gauge on either the first or second surface facilitates the detection of minute deformations due to force application, leading to improved measurement precision.

[0937] The meander-shaped structure offers increased mechanical stability while maintaining flexibility, which is essential for reliable force measurement over a wide range of operating conditions.

[0938] The measurement system provides the advantage of conductive pathways that enhance the accuracy of force measurements on the spindle.

[0939] The rotationally symmetric structure of the measurement system provides the advantage of uniform force distribution, leading to more reliable measurements.

[0940] The amortized design of the system contributes the advantage of reduced vibrations, which improves the stability of the measurements taken.

[0941] The elastic properties of the materials used in the measurement system provide the advantage of improved responsiveness to varying force levels, ensuring precise readings.

[0942] The balanced configuration of the measurement system offers the advantage of minimized mechanical stress, which prolongs the lifespan of the components involved.

[0943] In a development, the system further comprises a structure being rotationally symmetric around the central axis. The rotational symmetry of the structure around the central axis ensures uniform stress distribution when the spindle is subjected to torsional forces, contributing to consistent and repeatable measurements.

[0944] The symmetric design simplifies the manufacturing process, as it allows for the use of standard fabrication techniques, reducing production costs and complexity.

[0945] Rotational symmetry enhances the overall durability of the measurement system by minimizing potential points of weakness that could lead to premature failure under cyclic loading.

[0946] In a development, the system further comprises an intermediate part at least partly extending parallel to the central axis. This may especially be true for flanks of the U-forrn.

[0947] The parallel extension of the intermediate part contributes to the structural integrity of the meander form, ensuring that the measurement system remains accurate and reliable over time.

[0948] In a development, the system further comprises a meander form comprising a first groove and a second groove

[0949] - wherein the first groove is open to a surrounding and the second groove is open to the surrounding,

[0950] - wherein the first groove is positioned immediately radially inwards to the intermediate part, and

[0951] - wherein the second groove is positioned immediately radially outwards to the intermediate part.

[0952] The presence of the first and second grooves adjacent to the intermediate part creates zones of reduced stiffness, which amplifies the strain experienced by the strain gauge, leading to enhanced sensitivity of the force measurements. The grooves being open to the surrounding environment facilitate heat dissipation, which can improve the longevity of the strain gauges by reducing thermal stress.

[0953] The strategic positioning of the grooves allows for the calibration of the measurement system by selectively modifying the groove dimensions, thereby tailoring the system's response to specific measurement requirements.

[0954] In a development, the system further comprises a cover, the cover covering the first groove and the second groove

[0955] The cover over the grooves protects the strain gauges and the meander form from environmental contaminant...

Claims

CLAIMS1. Method of evaluating at least a vertical strain gauge (91) and a horizontal strain gauge (93) of a load cell being provided for measuring external forces applied on a spindle (14) of a motor unit (20), one side of the spindle (14) rotatably supported by a bearing in a bearing seat of a housing (22), wherein the strain gauges (91 , 93) are provided at the housing (22), in the vicinity of the bearing seat, wherein a rotationally symmetric gearbox arrangement is connected with the spindle (14), the gearbox arrangement transmitting torque from an electric motor (25) to the spindle (14), the vertical strain gauge (91) and the horizontal strain gauge (93) being arranged nonparallel to each other, the method comprising the following steps:- measuring a vertical measurement signal (97) of the vertical strain gauge (91), and- measuring a horizontal measurement signal (98) of the horizontal strain gauge(92) independently from the vertical strain gauge (91), and- measuring a further vertical measurement signal of a further vertical strain gauge(93), the further vertical strain gauge (92) being arranged parallel to the vertical strain gauge (91) on an opposite side of a spindle (14) of the motor unit (20), and- measuring a combined vertical measurement signal as a difference between a further vertical strain gauge (92) and the vertical strain gauge (91), and- applying a measure to compare the vertical measurement signal (97), the further vertical measurement signal, or the combined vertical measurement signal with the horizontal measurement signal (98), and- detecting an error if the measure is inside a predetermined error range, and- applying a measure to compare the vertical measurement signal (97) with the further vertical measurement signal, and- detecting an error if the measure is inside a predetermined error range.

2. Method according to claim 1 , wherein the vertical strain gauge (91) and the horizontal strain gauge (93) are arranged perpendicular to each other.

3. Method according to claim 1 or claim 2, wherein the combined vertical measurement signal is measured using a half bridge circuit.

4. Method according to one of the preceding claims, further comprising the following step:- measuring a further horizontal measurement signal of a further horizontal strain gauge (94), the further horizontal strain gauge (94) being arranged parallel to the horizontal strain gauge (93) on an opposite side of a spindle (14) of the motor unit (20).

5. Method according to one of the preceding claims, further comprising the following step:- measuring a combined horizontal measurement signal as a difference between a further horizontal strain gauge (94) and the horizontal strain gauge (93), the further horizontal strain gauge (94) being arranged parallel to the horizontal strain gauge (93) on an opposite side of a spindle (14) of the motor unit (20).

6. Method according to claim 5, wherein the combined horizontal measurement signal is measured using a half bridge circuit.

7. Method according to one of the preceding claims, wherein the strain gauges (91 , 92, 93, 94) are arranged with an angle difference of 90° to respective neighboring strain gauges (91 , 92, 93, 94).

8. Method according to one of the preceding claims, wherein the strain gauges (91 , 92, 93, 94) are arranged at a side of a floating bearing of a spindle (14) of the motor unit (20).

9. Method according to one of the preceding claims, wherein the strain gauges (91 , 92, 93, 94) are arranged at a side of a sprocket wheel (11) of the spindle (14) of the motor unit (20).

10. Method according to one of the preceding claims, wherein one or some of the strain gauges (91 , 92, 93, 94) are arranged at a first side of the gearbox arrangement and oneor some of the strain gauges (91 , 92, 93, 94) are arranged at a second side of the gearbox arrangement.

11. Method according to one of the preceding claims, wherein the vertical strain gauge (91) measures a driving force applied by a driver of an electric bicycle (10).

12. Method according to one of the preceding claims, wherein the horizontal strain gauge (93) measures a chain force of a chain (17) of an electric bicycle (10).

13. Method according to one of claims 4 or 5 or a claim depending on one of these claims, further comprising the following step: applying a measure to compare the vertical measurement signal (97), the further vertical measurement signal, or the combined vertical measurement signal with the further horizontal measurement signal, or the combined horizontal measurement signal, and detecting an error if the measure is inside a predetermined error range.

14. Method according to one of claims 4 or 5 or a claim depending on one of these claims, further comprising the following steps: applying a measure to compare the horizontal measurement signal (98) with the further horizontal measurement signal, and detecting an error if the measure is inside a predetermined error range.

15. Method according to one of the preceding claims, further comprising the following steps: detecting a local maximum (86) or local minimum (87) value in the vertical measurement signal (97), the further vertical measurement signal, or the combined vertical measurement signal, and instantly holding a motor (25) of the motor unit (20) in response to detecting the maximum (86) or minimum value (87).

16. Method according to claim 15, wherein the local maximum (86) or local minimum value (87) is determined by taking a temporal derivative and detecting a zero crossing in the temporal derivative.

17. Method according to one of claims 15 or 16, wherein the local maximum (86) or local minimum (87) value is determined by taking a derivative by an angular position of a spindle (14) of the motor unit (20), and detecting a zero crossing in the derivative.

18. Motor unit (20) for an electric bicycle (10), the motor unit (20)comprising an electric motor (25) with a gearbox arrangement with a spindle (14) for applying an external force to the motor unit (20), the gearbox arrangement transmitting torque from the electric motor (25) to the spindle (14), the gearbox arrangement having a first side and a second side, a control unit (40), at least one bearing rotatably supporting the spindle (14) in a bearing seat of a housing (22), a load cell (90) with at least a first strain gauge (91 ) being a vertical strain gauge and / or a second strain gauge (92) being a vertical strain gauge, and with a third strain gauge (93) being a horizontal strain gauge and / or a fourth strain gauge (94) being a horizontal strain gauge, the load cell (90) being provided for measuring an external force that is applied to the motor unit, wherein at least one strain gauge (91 , 92, 93, 94) is provided at the housing (22), in the vicinity of the bearing seat.

19. Motor unit (20) according to claim 18, comprising a fixed bearing holding the spindle (14) at the first side of the gearbox arrangement, a loose bearing holding the spindle (14) at the second side of the gearbox arrangement being axially opposite to the first side with respect to the spindle (14), and / or a sprocket wheel (11) being arranged on the spindle (14).

20. Motor unit (20) according to claim 19, further comprising a memory unit, the memory unit comprising software causing the control unit (40) to perform a method according to one of claims 1 to 17; and / or wherein the control unit (40) is configured to perform a method according to one of claims 1 to 17.21 . Motor unit (20) according to one of claims 18 to 20, wherein the sprocket wheel (11) is arranged at the second side of the gearbox arrangement.

22. Motor unit (20) according to one of claims 18 to 21 , wherein the sprocket wheel (11) is arranged rotationally fixed on the spindle (14).

23. Motor unit (20) according to one of claims 18 to 22, wherein the motor unit (20) has one single freewheel, the freewheel being arranged between a gear of the gearbox arrangement and the spindle (14).

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