Pedal propulsion vehicle gear system and method of operating the same

Abstract

A system and method for operating a pedal propelled vehicle gear system, the system comprising: a multi-speed gear (110, 290) configured to provide varying gear ratios between a gear input element (111) and a gear output element (112), wherein the method comprises: receiving a shift control signal (172) indicating that a shift should be performed; providing an upshift control signal (153) to a motor to operate at an upshift torque bT for an upshift torque time period tbT; providing a downshift control signal (154) to the motor to operate at a downshift torque dT for a downshift torque time period tdT, wherein the upshift torque is higher than the downshift torque.

Description

Technical Field

[0001] This invention relates to a pedal-driven vehicle gear system. The invention is particularly relevant to vehicles with multiple gears, in which the shifting system is performed under torque and / or the vehicle's performance is significantly affected by torque losses during gear shifts. Such vehicles can be, for example, pedal-driven vehicles, in which pedaling requires no assistance or is assisted by, for example, a motor from an electric bicycle. Background Technology

[0002] As initially stated, the present invention can be used in a wide range of applications. One such application is pedal-propelled vehicles.

[0003] Most pedal-powered vehicles (such as bicycles) are equipped with some selectable gear ratio to improve pedaling efficiency and comfort.

[0004] Unlike gears in other motor-driven vehicles where the gear system and motor drive system can work together during gear shifts, bicycle control systems cannot control the rider and the torque applied to the pedals in the same way.

[0005] Therefore, experienced riders gradually develop their own understanding and application of shifting techniques. The optimal shifting method will depend on the type of bicycle, the characteristics of the rider, etc., which means that there is actually no single shifting method.

[0006] This is difficult to handle, and it is easy to observe that inexperienced riders, and even experienced riders, struggle to shift gears effectively in certain situations.

[0007] With the introduction of electric bicycles where pedaling is powered by a motor drive, the same problem persists. Shift control systems can control the contribution from the motor, but not the contribution from the rider.

[0008] While many experienced riders in the sport have accepted and even understood the importance of gradually developing their own shifting techniques, shifting remains an obstacle for many riders and for any pedal-powered vehicle with electric support, such as standard e-bikes, lightweight e-bikes, e-cargo vehicles with two or more wheels, mountain bikes, recreational bikes, commuter bikes, etc. This problem is becoming increasingly severe as the number of such vehicles and affected riders increases.

[0009] Civic frequency is defined as the number of revolutions of the crankshaft per unit time. This is also called cadence and is mostly defined as revolutions per minute (rpm).

[0010] Although each rider's optimal cadence is unique, it is clear that human physiology generally does not allow for large variations in cadence in order to maintain effective power generation and comfort.

[0011] Therefore, most modern bicycles are equipped with some form of variable gear mechanism to change the relationship between cadence and the speed of the drive wheel. By changing the gear ratio, the desired cadence can be selected for different speeds and different riding conditions (e.g., uphill or downhill).

[0012] The shifting system is performed by a shifting mechanism. The type of shifting mechanism depends on the type of gear system used in the specific situation.

[0013] However, effective gear shifting on a bicycle requires precision and timing. Experienced riders know they should shift near the crank's dead center to reduce the torque exerted on the gear mechanism by the rider's foot. High torque makes shifting more difficult and typically shortens the lifespan of the shifting mechanism and transmission.

[0014] Electric bicycles increase the complexity of gear shifting. In addition to the torque from the rider, the torque from the motor must also be considered. If an experienced rider releases the pedal to shift, the shifting mechanism will still struggle due to the high torque from the motor. Conversely, even if the control system can temporarily reduce the torque from the motor during shifting, the high torque from the rider indicates shifting problems.

[0015] Therefore, there is a need for an improved shifting mechanism that enables both experienced and inexperienced riders to shift gears smoothly and effectively, whether with or without assisted pedaling.

[0016] WO2012128639A1 and WO2020130841 disclose multi-speed gears for pedal-driven vehicles.

[0017] WO207149396 discloses a sequential shifter for multi-speed systems.

[0018] Gear systems have input and output components. In the case of vehicle gears designed for propulsion, the input and output components are typically rotating elements; therefore, the input component is a rotating input element, and the output component is a rotating output element. By changing the gear ratio between the input and output components, a varying speed difference and a varying relative torque between them are achieved.

[0019] Between input and output elements, interacting mechanical gear elements (e.g., meshing gears) engage and disengage to provide gear shifting. Depending on the relative torque between the input and output elements, more or less force will be required for the engagement and disengagement of the gear elements. When the shifting element moves axially or radially to engage or disengage the gear elements, the linear force required for engagement / disengagement can increase with the torque between the input and output elements. The same applies to rotary shifting elements, but in this case, it is the shifting torque that increases.

[0020] A vehicle's performance depends more on its overall weight than on anything else. Therefore, minimizing the weight of the gear system is crucial. This is especially important for pedal-powered vehicles (e.g., bicycles at least partially operated by the rider). While the reduction in mechanical strength and durability of the gear assembly due to weight and size reduction can be partially compensated by choosing alternative materials, there is always a critical torque limit for shifting based on the mechanical characteristics of the available gear components.

[0021] It should be mentioned that when trying to reduce weight and size while maintaining the mechanical strength of a particular gear design, material costs will increase significantly.

[0022] Mechanical shifting relies on the engagement and disengagement of mechanical components, such as ratchet or dog clutches. When these components are properly designed, they provide a robust mechanical connection when fully engaged and are not adversely affected by wear. Furthermore, mechanical wear is not a significant issue when the components are fully disengaged.

[0023] However, when a mechanical component is in an intermediate state between being fully engaged and fully disengaged, it is only partially connected and may break or wear under high torque. During gear shifting, the gear mechanism will be in this intermediate state.

[0024] With a fixed torque, the longer mechanical components remain in the intermediate stage, the more they wear out. Furthermore, mechanical components at high torque typically remain in the intermediate stage for a longer period compared to those at low torque.

[0025] Shift time (i.e., the time a mechanical component remains in the intermediate stage) depends on the actuation force and actuation speed. The actuation force is the force that engages or disengages the mechanical components. If the force is greater, it is easier to overcome the reaction force generated by the torque between the mechanical components.

[0026] Manual shifting is used in many gear systems. In this case, the actuation force depends on the force applied by the operator. Some operators may be able to provide greater force, while others can only apply more limited force. While excessive force can damage the internal mechanical components or actuation mechanism of the gears, insufficient force may hinder shifting.

[0027] To reduce wear, shifting time, and necessary actuation force, many cyclists have gradually developed the habit of shifting gears at low torque (for example, when the pedals are close to vertical, i.e., at top dead center, TDC).

[0028] Increasingly, gear systems incorporate auxiliary actuation, such as electric shift actuators located close to the gear unit. The actuation torque and speed of these shift actuators are determined by design, and existing electric shift actuators typically do not provide sufficient shift reliability and speed, especially under challenging conditions such as high torque.

[0029] Therefore, a common problem with pedal-driven gear systems is that shift times are too long and they are unreliable. Summary of the Invention

[0030] The present invention provides a pedal-driven vehicle gear system and a method for operating the pedal-driven vehicle gear system, wherein the problems identified above have been solved.

[0031] Specifically, the present invention provides a computer-implemented method for operating a pedal-driven vehicle gear system, wherein the gear system includes: a multi-speed gear configured to provide a varying gear ratio between a gear input element and a gear output element; a crank drive configured to transmit torque to the gear input element; a motor drive configured to transmit torque to the gear input element; and a movable shifting element configured to shift the multi-speed gear between gear ratios, wherein the method includes:

[0032] - Receive a shift control signal indicating that a shift should be performed;

[0033] - Provides an upward control signal to the motor driver to operate during the upward torque period; and

[0034] - Provide a descent control signal to the motor to operate during the descent torque period, where the descent torque is higher than the descent torque.

[0035] The gear system has a current shift torque threshold, which represents the maximum torque between the gear input element and the gear output element used to perform gear ratio changes in a multi-speed gear system.

[0036] The present invention has the following advantages over the prior art.

[0037] First, a multi-speed gear system having the gear system and method according to the present invention will shift gears more quickly than prior art solutions in many cases, and can reduce torque loss during gear shifting.

[0038] In the case of pedal-powered vehicles, gear shifting will be more reliable and predictable because it relies less on the rider's behavior.

[0039] In many cases, gear systems and methods can be easily integrated with existing multi-speed gears.

[0040] The gear system and method include only a small number of components that are easy to manufacture.

[0041] Without the proposed additional features, the gear system and method require little or no additional space in the prior art shift actuator.

[0042] Due to the high available torque, the gear system and corresponding methods are able to perform gear shifts quickly.

[0043] The gear system and method can be used for upshifting and downshifting.

[0044] Regardless of whether the multi-speed gear system is configured in the wheel hub or near the crank of a pedal-driven vehicle, the gear system and method can be used in different types of vehicle constructions. Attached Figure Description

[0045] Figure 1 An embodiment is illustrated in the diagram, in which the multi-speed gear and the crank drive are located in the same position.

[0046] Figure 2 An embodiment is illustrated with a schematic diagram, wherein a multi-speed gear system is configured in a wheel hub.

[0047] Figure 3 , Figure 4 , Figure 5 and Figure 6 The operation of a pedal-driven vehicle gear shifting system according to an embodiment of the present invention is illustrated using a combined time and torque / energy graph.

[0048] Figure 7 and 8 The shift actuator 121 is illustrated in an isometric sectional view, which can be used in embodiments of the present invention to obtain reduced switching time and accuracy.

[0049] Figure 9 Using a view to illustrate, as Figure 8The energy storage element 30 is shown. It can be seen that the opposing through holes 35 and 36 each extend into two cuts 35a, 35b and 36a, 36b, respectively, extending from the through hole toward the first end of the sleeve in opposing curved or helical directions. The complete cut including the through hole 35 and the two helical extending cuts 35a, 35b has a first "V" shape. The through hole 36 and the two helical extending cuts 36a, 36b define a similar "V" shape laterally opposite to the first "V" shape. Furthermore, it can be seen that the first end 34a of the sleeve is configured to connect to an energy source configured to rotate the sleeve relative to the shift shaft.

[0050] Figure 10 The components of the previously described energy storage element 30 are illustrated in an exploded view. After assembly, a spring is preloaded within the sleeve. That is, the first end of the spring abuts against the inner wall of the first end of the sleeve, and the second end abuts against a retaining member, which is forcefully pushed into the sleeve before the pin passes through the through hole in the sleeve and the retaining member.

[0051] Figure 11 The left side schematically illustrates how the inherent hardware limitations of the gear system prevent shifting from occurring when the current shift torque threshold (current STT) is exceeded.

[0052] Figure 11 The right side of the diagram schematically illustrates how to use the present invention for gear shifting even when the total torque of the entire gear system is the current STT.

[0053] Figure 12 An adaptive STT according to an embodiment of the present invention is illustrated by a flowchart.

[0054] Figure 13 and Figure 14 A shift actuator 201, with and without housing 200, is illustrated in isometric view. This shift actuator can be used in embodiments of the invention to achieve reduced switching time and increased accuracy. Internal components are concealed by housing 200. The top of the housing has electrical connectors for power supply and connection to a control system. Communication with the control system can also be wireless, in which case a physical control interface is not required.

[0055] Figure 15 An alternative shift actuator 202 that allows longitudinal movement of the shift shaft 210 is illustrated in cross-section and partial schematic diagram according to one embodiment of the present invention.

[0056] Figure 16 This is a cross-sectional view of an energy storage element 230 according to one embodiment of the present invention, and it is explained. Figure 13 , Figure 14 and Figure 15 Details of the energy storage element 230 shown.

[0057] Figure 17a Explained with partial cross-sectional views Figure 13 and Figure 14 The vehicle shift actuator 201. Here, the energy storage element 230 is in the lower position, where the energy storage element is loaded with energy that pushes the energy transmission element 250 upward and thus provides a counterclockwise torque on the shift shaft 210.

[0058] Figure 17b Explained with partial cross-sectional views Figure 13 and Figure 14 The vehicle shift actuator 201. Here, the energy storage element 230 is in the upper position, where the energy storage element is loaded with energy that pushes the energy transmission element 250 downward and thus provides clockwise torque on the shift shaft 210.

[0059] Figure 18 The shift actuator 201 of the internal multi-speed hub gears in a pedal-operated vehicle is illustrated using schematic diagrams and isometric views. The multi-speed gear system 290 includes a planetary gear set and may be, for example, the gear type disclosed in WO20201230841. A battery 222, which supplies power to the motors of the control system and shift system, is shown connected via an electrical connector. The battery may be located, for example, within a seat pin or in any other suitable location. A wireless gear actuator 70, configured on the handlebars, is connected to the control system. Detailed Implementation

[0060] In the following description, various examples and embodiments of the invention are set forth to provide those skilled in the art with a more thorough understanding of the invention. The specific details described in the context of the various embodiments with reference to the accompanying drawings are not intended to be construed as limiting. Rather, the scope of the invention is defined in the appended claims.

[0061] The embodiments described below are numbered. Furthermore, supplementary embodiments defined with respect to the numbered embodiments are described. Unless otherwise stated, any embodiment that can be combined with one or more numbered embodiments may also be directly combined with any supplementary embodiment of the mentioned numbered embodiments.

[0062] EM1: A computer-implemented method for operating a pedal-driven vehicle gear system 100, wherein the gear system 100 includes:

[0063] Multi-speed gears 110 and 290 are configured to provide a varying gear ratio between gear input element 111 and gear output element 112, wherein the method includes:

[0064] Receive shift control signal 172 indicating that a shift should be performed;

[0065] A boost control signal 153 is provided to the motor driver to operate at a boost torque bT for a boost torque time period tbT.

[0066] A dip control signal 154 is provided to the motor to operate at a dip torque dT for a dip torque time period tdT, wherein the rise torque is higher than the fall torque.

[0067] In a first subsidiary embodiment, the gear system includes movable shift elements 10, 210 configured to shift gears in the multi-speed gear.

[0068] In a second subsidiary embodiment that can be combined with the first subsidiary embodiment, the gear input element is configured to be driven by both the crank driver 130 and the motor driver 140.

[0069] EM2: According to the method of EM1, the gear system has a current shift torque threshold (STT), where the current STT represents the maximum torque between the gear input element 111 and the gear output element 112 used to perform gear ratio changes in the multi-speed gear. That is, if the total torque of the entire multi-speed gear is higher than the current STT, shifting cannot be performed. The total torque can be the sum of the torque contributions from the crank drive and the motor drive.

[0070] Even when there is no contribution from the rider and motor (i.e., total torque is zero), shifting from one gear to another requires a certain minimum actuation torque. This is due to the force required to move the clutch and / or gears within the gear system. The minimum actuation torque can depend on factors such as temperature and lubricant viscosity. The minimum actuation torque can also depend on the specific gear shift being performed, such that, for example, the minimum actuation torque from second to third gear may be greater than the minimum actuation torque from third to fourth gear.

[0071] Therefore, a gear shift can only be performed when the total torque of the entire multi-speed gear is lower than the current STT and the actuator torque is higher than the minimum actuation torque.

[0072] In the first subsidiary embodiment, the current STT of the gear system is within the range of being equal to or greater than the minimum STT and equal to or less than the maximum STT.

[0073] In a second subsidiary embodiment that can be combined with any of the subsidiary embodiments described above, the maximum STT is a predetermined value determined based on the worst-case shift torque, such as the worst operating temperature, the end of a maintenance period, or a new gear assembly.

[0074] In a third subsidiary embodiment that can be combined with any of the above subsidiary embodiments, the minimum STT is a predetermined value determined based on the optimal shift torque, such as the optimal operating temperature, the start of the maintenance period, the break-in period of the gear assembly, etc.

[0075] In a fourth subsidiary embodiment, which can be combined with any of the aforementioned subsidiary embodiments, the maximum and / or minimum STT are shift-specific. That is, they have specific values ​​for each shift, for example, one set of values ​​for shifting from third to fourth gear and another set of values ​​for shifting from fourth to fifth gear. Upshifts and downshifts can also typically have different values.

[0076] EM3: The method according to EM2, wherein the method includes:

[0077] The crank torque signal 132 is received from the crank torque sensor 131, the crank torque signal representing the torque difference between the crank drive and the gear input element; and

[0078] The motor torque signal 142 is received from the motor driver. This motor torque signal represents the torque difference between the motor driver and the gear input element.

[0079] The sum of the rising torque and the crank torque from the crank torque signal is higher than the current STT; and

[0080] The sum of the reduced torque and the crank torque from the crank torque signal is lower than the current STT.

[0081] In a first subsidiary embodiment, the method includes:

[0082] After receiving the shift control signal and before providing a control signal to the motor to operate at the rising torque bT, a pre-rise control signal 152 is provided to the motor to operate at a pre-rise torque time period tpbT at a pre-rise torque pbT, wherein the pre-rise torque is lower than the rising torque and higher than the falling torque.

[0083] In a second subsidiary embodiment that can be combined with the first subsidiary embodiment, this method includes:

[0084] A crank torque signal 132 is received from the crank torque sensor 131, which represents the crank torque as the torque difference between the crank drive and the gear input element.

[0085] Receive motor torque signal 142 from the motor driver, which represents the motor torque as the torque difference between the motor driver and the gear input element;

[0086] The total torque is calculated as the sum of the crank torque and the motor torque; and

[0087] The pre-rise control signal 152 is provided only when the total torque is below the pre-rise torque threshold.

[0088] In a third subsidiary embodiment, which can be combined with the first or second subsidiary embodiment, the pre-rising torque threshold is the same as the current STT.

[0089] In a fourth subsidiary embodiment that can be combined with the third subsidiary embodiment, the pre-rising torque threshold is the current STT plus the torque safety margin.

[0090] EM4: The method according to any one of EM1 to EM3 above, wherein the multi-speed gear includes shift actuators 121, 201, 202 configured to move shift elements 10, 210, and the method includes:

[0091] Before providing an up control signal to the motor driver 140, a first shift signal 143 is transmitted to the shift actuator.

[0092] In an alternative embodiment that can be combined with the alternative embodiment of EM3, the method includes:

[0093] After providing the pre-rise control signal, the first shift signal 143 is transmitted to the shift actuator.

[0094] When using a shift actuator to operate the shift elements (e.g., shift shaft) of this gear system, the shift torque threshold may be limited by the maximum torque of the shift actuator, rather than the mechanical strength of the gear elements. If the shift actuator has a high maximum torque, shifts can be performed at a higher torque across the entire gear system compared to a shift actuator with a low maximum torque. That is, the current STT becomes a function of the maximum torque that the shift actuator can transmit. In other words, in order to be able to shift under heavy loads (i.e., large total torque), the actuator torque should be high.

[0095] EM5: The method according to any one of EM1 to EM4 above, wherein the gear system includes shift actuators 121, 201, 202 configured to move shift elements 10, 210, wherein the shift actuators are configured to have a maximum actuator force and / or a maximum actuator torque acting on the shift elements, wherein the method includes setting the maximum actuator force and / or the maximum actuator torque.

[0096] In a first subsidiary embodiment, the method includes modifying the current STT by modifying the maximum actuator force and / or the maximum actuator torque. The current STT is here a function of the shift actuator force and / or torque.

[0097] EM6: Based on any of the methods from EM2 to EM5, including: setting a set shift torque threshold representing the current STT (Set STT).

[0098] In the first subsidiary embodiment, the set STT is within the range between the maximum STT and the minimum STT.

[0099] In the second subsidiary embodiment, the set STT is equal to the maximum STT, and optionally has an additional safety margin.

[0100] The success of a gear shift can be measured by detecting a sudden drop in the current of the servo motor of the shift actuator.

[0101] According to the method of any of EM5 to EM6, including:

[0102] Measure the success rate of a series of gear shifts.

[0103] In a first subsidiary embodiment, the method includes:

[0104] The success of a gear shift is measured by detecting the decrease in actuator torque from a high value to a low value.

[0105] In a second subsidiary embodiment, the actuator is driven by a power source, and the actuator force and / or torque are measured by measuring the current from the power source to the actuator, wherein a higher force and / or torque value corresponds to a higher current than a lower force and / or torque value.

[0106] A sudden drop in current indicates a change in actuator position, but does not necessarily mean a full gear shift has occurred. Further measurement of the speed difference between the gear input and output elements can be compared to the expected gear ratio to determine actual success. In this case, all gear ratios expected to be available in the control system are considered. The speed difference between the gear input and output elements can be measured by a rotation sensor.

[0107] In the third subsidiary embodiment, the measurement of successful gear shift includes:

[0108] Measure the input speed on the input element;

[0109] Measure the output speed on the output element;

[0110] The input and output speeds are compared to the expected input and output speeds. If the input and output speeds equal the expected input and output speeds, the shift is successful; otherwise, it fails. Instead of measuring and comparing individual values, the speed difference can be compared to a known speed difference. Speed ​​measurement can be performed using a tachometer.

[0111] According to the EM7 method, it includes:

[0112] If the success rate is higher than the predetermined high success rate threshold, increase the set STT and / or decrease the actuator force / torque.

[0113] In a first subsidiary embodiment, the method includes:

[0114] If the success rate is below the predetermined low success rate threshold, reduce the set STT and / or increase the actuator force / torque.

[0115] The high success rate threshold is higher than or equal to the low success rate threshold.

[0116] In a third subsidiary embodiment, this method includes:

[0117] Set a predetermined low success rate threshold and / or high success rate threshold.

[0118] The set STT and / or actuator force / torque can be increased and / or decreased for individual shifts, a group of shifts, or all shifts.

[0119] exist Figure 12 This describes an embodiment of an adaptive shift torque threshold.

[0120] EM9: Based on any of the methods described in EM2 to EM8 above, including modifying any one of the rising torque bT, the rising torque time period tbT, the falling torque dT, and the falling torque time period tdT.

[0121] In one additional embodiment, the method includes modifying the pre-rise torque pbT and / or the pre-rise torque time period tpbT.

[0122] This can be done with or without modifying STT to achieve the desired shift success rate that can be defined in the same way as described above.

[0123] That is, increase the torque drop period tdT to give more time to shift gears, or increase the torque rise period tbT to allow the actuator more time to obtain the necessary torque to increase STT to the required level.

[0124] To illustrate the shift torque threshold STT, a specific case is considered: if the total torque of the entire multi-speed gear exceeds 18 Nm (STT in this case), then a shift from second to third gear should not or cannot be performed. If, for example, the rider's torque contribution on the crank alone is 20 Nm, and the motor's contribution is 10 Nm, then even if the motor's contribution is reduced to zero, such a shift is impossible.

[0125] As previously disclosed, the current STT will depend on the design of the multi-speed gear system. If manual operation is used, it can be based on calculations of the mechanical strength of internal gear components, clutches, etc., and / or external gear components (e.g., actuation lines, etc.). If auxiliary actuation (e.g., actuation servo systems, actuation solenoids, etc.) is used, the current STT is generally limited by the force or torque provided by the actuator.

[0126] By increasing the size of the actuator and the capacity of the actuator power supply, high actuator torque and high current STT can be provided. However, this is still not the preferred solution for pedal-driven vehicles and other types of vehicles.

[0127] The following will present an embodiment relating to a method for operating a pedal-driven vehicle gear system, which is based on a lightweight and small actuator to improve shifting performance, particularly under higher loads.

[0128] EM10: The method according to any one of the above embodiments EM1 to EM9, wherein the shift actuators 121, 201, and 202 include:

[0129] Movable shift elements 10 and 210 are configured to shift gears in a multi-speed gear system;

[0130] Energy source 220; and

[0131] Energy storage element 230,

[0132] The energy source is configured to load or charge the energy storage element with potential energy, wherein the shift torque threshold is determined by the potential energy, and the energy storage element is configured to move the shift element.

[0133] In a first subsidiary embodiment, the energy storage element is configured to move the shifting element in two opposite directions from the equilibrium position, wherein the energy storage element is neither charged nor loaded with energy from an energy source.

[0134] In a second subsidiary embodiment, which can be combined with the first subsidiary embodiment, the energy source is configured to load or charge the energy storage element with positive and negative potential energy relative to the equilibrium position. The sign of the energy depends on the selected direction of movement.

[0135] In a third subsidiary embodiment, which can be combined with the first or second subsidiary embodiment, the energy storage element is preloaded with energy at the equilibrium position.

[0136] In the fourth subsidiary embodiment, this method includes:

[0137] Control the energy supplied from the energy source.

[0138] EM11: According to the method of EM10, including:

[0139] Energy transfer from the energy source to the energy storage element begins at start time t0; and

[0140] Energy transfer ends at a predetermined time interval ts1 after the start time, or when the storage element has reached a specific position or rotation angle.

[0141] In the latter case, a position or rotation sensor can be applied. A combination of these two methods to terminate energy transfer is also possible, where a predetermined time interval ts1 is set long enough to always reach a specific position or rotation angle during normal shifting. If any error occurs, the loading will stop after this predetermined time interval ts1, even if a shift does not occur for some reason.

[0142] Figure 4 , Figure 5 and Figure 6 The lower part describes the energy transfer to the energy storage element in the shift actuator. Energy transfer begins at t0, and after a specific time following the entry into the rising torque period tbT, the storage element is fully charged with actuation energy. The remaining time in this rising torque period is a safety time, as shown in the flat area, to ensure that the storage element is fully loaded before a shift occurs due to the downshift control signal.

[0143] In the first subsidiary embodiment, energy transfer continues until a descent control signal is transmitted to ensure that its storage element remains fully loaded.

[0144] In a second subsidiary embodiment, the gear system includes a gear manipulator 70, which includes a gear manipulator sensor 71 connected to a control system and configured to detect one or more gear shifts of the gear manipulator, wherein the control system is configured to set a start time t0 when or after the gear manipulator sensor detects a gear shift.

[0145] In a third subsidiary embodiment that depends on the second subsidiary embodiment, the method includes:

[0146] Energy transfer begins when or after the gear shifter sensor detects a single gear shift.

[0147] In a fourth subsidiary embodiment that depends on the second or third subsidiary embodiment, the method includes:

[0148] Energy delivery begins when or after a double shift is detected by the gear operator sensor, wherein the time interval between the double shifts is twice the time interval between the single shifts.

[0149] In the fifth subsidiary embodiment, this method includes:

[0150] The cadence is detected from the cadence detector;

[0151] Energy delivery begins when the cadence is higher than or equal to the upper threshold or lower than or equal to the lower threshold.

[0152] In the sixth subsidiary embodiment, for a single gear shift, the predetermined time interval ts1 is less than 0.5s, less than 0.3s, or less than 0.2s.

[0153] In the sixth subsidiary embodiment, the sign of energy transfer depends on whether the control system initiates an upshift or downshift.

[0154] In a seventh subsidiary embodiment, the shifting element includes an end stop for a physical entity used for calibration, wherein the end stop is located outside the region between the upper gear and the lower gear.

[0155] In the eighth subsidiary embodiment, this method includes:

[0156] As part of the initialization process, the shift element is moved until it reaches the end stop.

[0157] EM12: A method according to any one of EM6 to EM11, including:

[0158] After the control system has transmitted the descent control signal 154, the energy transfer ends when the motor torque drops below the set STT.

[0159] In a first subsidiary embodiment, the method includes:

[0160] The energy transfer ends when the gear position detector indicates that at least one gear has been shifted.

[0161] EM13: According to any one of EM10 to EM12, wherein the energy source is a servo motor configured to provide rotational energy.

[0162] In a first subsidiary embodiment, the method includes starting and stopping a servo motor.

[0163] In a second subsidiary embodiment that can be combined with the first subsidiary embodiment, the method includes operating a servo motor in both forward and reverse directions.

[0164] EM14: According to any one of EM10 to EM13, the gear system includes a reduction mechanism 40, 240 arranged between an energy source and an energy storage element, wherein the reduction mechanism is configured to transmit energy from a servo motor to the energy storage element.

[0165] In the first subsidiary embodiment, the reduction mechanism is a reduction gear.

[0166] In the second subsidiary embodiment, which is based on the first subsidiary embodiment, the reduction gear is a single-input / single-output reduction gear.

[0167] In this embodiment, the reduction gear may be a two-stage or a three-stage reduction gear.

[0168] EM15: The method according to any one of EM10 to EM14, wherein the energy storage element includes: elastic mechanical elements 31, 231, configured to elastically deform between the input element and the output element.

[0169] In the first embodiment, the input and output components of the elastic mechanical element are respectively connected to an energy source and a movable shifting element. Optionally, the input component is connected via reduction mechanisms 40 and 240.

[0170] In a second subsidiary embodiment, which can be combined with the first subsidiary embodiment, the elastic mechanical element is mechanically preloaded. That is, it elastically deforms when the energy source does not provide energy.

[0171] EM16: According to any of the methods of EM10 to EM15, wherein the movable shifting element is a shifting shaft.

[0172] In a first subsidiary embodiment, the method includes rotating a shift shaft to change the gears of a multi-speed gear system.

[0173] EM17: According to any one of EM15 to EM16, wherein the elastic mechanical element is configured as a spring loaded with potential energy.

[0174] In the first subsidiary embodiment, the elastic mechanical element is a helical spring.

[0175] In a second subsidiary embodiment that follows the first subsidiary embodiment, the helical spring is preloaded by compression with a force of at least 0.1 or 0.2 Nm.

[0176] In a third subsidiary embodiment, the shift shaft includes one or more longitudinal slots in its inner walls 11a, 11b, and the energy storage element includes a pin 32 adjacent to the output end or second end 31b of the coil spring, wherein the end of the pin is disposed in one or more slots in the inner wall of the shift shaft and is prevented from rotating relative to the shift shaft but is allowed to move longitudinally relative to the shift shaft. The pin is configured to compress the spring when pushed against the second end of the spring.

[0177] In a third subsidiary embodiment that can be combined with the second subsidiary embodiment, the energy storage element includes: a fixing member 33, including a radially guiding protrusion extending into a second end of a helical spring, wherein the pin is disposed in a transverse hole in the fixing member.

[0178] EM18: According to the method of EM17, the energy storage element includes: a sleeve 34 having a first end and a second end 34a, 34b longitudinally disposed inside the shift shaft, wherein a spring and a fixing member are disposed inside the sleeve, and wherein the fixing member is configured to rotate and slide within the sleeve.

[0179] In the first subsidiary embodiment, the outer diameter of the sleeve is similar in cross-section to the inner diameter of the shift shaft.

[0180] EM19: According to the method of EM18, the wall of the second end of the sleeve includes a through hole for a pin.

[0181] In the first subsidiary embodiment, the spring is a helical spring, and the position of its through hole corresponds to the position of the pin when the helical spring is preloaded but in the equilibrium position (i.e., not compressed or loaded by potential energy from the energy source).

[0182] In a second subsidiary embodiment that can be combined with the first subsidiary embodiment, the wall of the second end 34b of the sleeve includes two cutouts 35a, 35b and 36a, 36b, extending in opposite directions from the through hole toward the first end of the sleeve.

[0183] The cut can be curved along the outer periphery of the sleeve wall, wherein, for the curved segment of the curve in the direction from the second end to the first end of the sleeve, the transverse component of the curve increases faster than the longitudinal component.

[0184] The incision can be symmetrical about the longitudinal axis.

[0185] In a third subsidiary embodiment that can be combined with the second subsidiary embodiment, the outer perimeter length of each cut corresponds at least to one rotation of the pin and the shift shaft (one single shift). That is, if one single shift corresponds to a 10-degree rotation of the shift shaft, then the outer perimeter length of its cut corresponds to a sector arc, wherein the radius of the sector is the radius of the sleeve, and the angle of the sector is 10 degrees.

[0186] In a fourth subsidiary embodiment, which can be combined with the second or third subsidiary embodiments, the longitudinal length of the cut corresponds at least to the compression of the spring during a single shift when the pin and shift shaft are rotated once.

[0187] In a fifth subsidiary embodiment, which can be combined with any of the second to fourth subsidiary embodiments, the length of the cut in the sleeve wall corresponds at least to one double shift or two consecutive single shifts of the pin and shift shaft. The outer circumference length of the cut allows the pin to rotate twice for two consecutive shifts, i.e., 20 degrees if each shift is 10 degrees as described above.

[0188] In a sixth subsidiary embodiment, which can be combined with any of the second to fourth subsidiary embodiments, the longitudinal length of the cut corresponds at least to the compression of the spring when the pin and shift shaft are rotated once for a double shift or twice for a single shift.

[0189] The notch allows the pin to move relative to the sleeve in both the longitudinal and rotational directions while being constrained by the notch.

[0190] Furthermore, according to any embodiment of the pin, sleeve, or shift shaft mentioned, these elements may be symmetrical about a longitudinal plane, wherein the shift shaft includes two opposing longitudinal grooves, the pin has two protruding ends disposed in each of the respective longitudinal grooves in the shift shaft, and the sleeve includes two opposing through holes for the pin.

[0191] The pin is pushed into the through-hole of the sleeve by the force of the spring. As previously mentioned, this spring can also be preloaded. When an energy source (e.g., a servo motor) rotates the sleeve via a reduction gear, the pin rotates the shift shaft accordingly. This is the case when the shift shaft rotates freely and no reverse torque is established.

[0192] When the shift shaft resists rotation due to reverse torque, the pin is pushed laterally and longitudinally into the slit in the sleeve from the through hole. However, because the slit has a longitudinal component, the coil spring is compressed in the longitudinal direction, and as the spring is compressed, the torque acting on the pin on the shift shaft increases. When the pin's torque increases to exceed the absolute value of the reverse torque, the spring's potential energy is released in a very short time during spring expansion, forcing the pin to travel along the curved path of the slit.

[0193] When the elastic mechanical element (i.e., the spring) is preloaded by compression, the pin will remain in the through hole as long as the absolute value of the reverse torque is less than the torque generated by the preloaded spring, thus pushing the pin toward the second end 34b of the sleeve.

[0194] The embodiments EM8 to EA19 above describe a gear system based on energy storage in a compression spring. However, in another embodiment, energy may be stored in a rotating or torsional elastic element.

[0195] EM20: According to any one of EM10 to EM19, wherein the spring is configured to store rotational potential energy.

[0196] In a first subsidiary embodiment, a first end of the elastic element is connected to an energy source 20, wherein the energy source is configured to rotate the first end of the spring.

[0197] In a second subsidiary embodiment that can be combined with the first subsidiary embodiment, the second end of the elastic element is rotatably connected to the shift shaft of the multi-speed gear system, and the elastic element is configured to cause the shift shaft to rotate when the torque at the second end of the elastic element increases to a level higher than the reverse torque of the shift shaft.

[0198] In a third subsidiary embodiment, which can be combined with the first or second subsidiary embodiment, the elastic element is a torsion spring.

[0199] In a fourth subsidiary embodiment, which can be combined with any of the first to third subsidiary embodiments, the elastic element is preloaded in one or both rotational directions. Alternatively, two springs preloaded in opposite rotational directions can be used.

[0200] Unless otherwise specified, the energy source in any embodiment may be, for example, an electric motor, a solenoid, or a hydraulic or pneumatic motor.

[0201] In any embodiment, this gear system can be hollow, wherein any of the sleeve, elastic element, fixing member, etc., is hollow. When this gear system is configured in a wheel hub, wheel bolts are allowed to pass through it.

[0202] EM21: According to the method of any one of EM1 to EM20, wherein the method features are executed sequentially.

[0203] EM22: The method according to any one of EM1 to EM17, wherein the shift actuator 201 includes: a longitudinal energy transfer element 250 configured to interconnect the shift element 210 with the energy storage element 230; and wherein the energy source 220 is configured to load or charge the energy storage element 230 with potential energy by moving the energy transfer element 250 relative to the energy storage element in its longitudinal direction.

[0204] In the first subsidiary embodiment, the energy transfer element 250 is rotatably fixed to the energy storage element 230.

[0205] In a second subsidiary embodiment that can be combined with the first subsidiary embodiment, the energy source 220 is configured to rotate the energy transfer element 250 and the energy storage element 230.

[0206] In a third subsidiary embodiment that can be combined with the second subsidiary embodiment, the energy transfer element 250 is configured to move longitudinally relative to the energy storage element 230 when the energy storage element 230 rotates via the energy source 220 and the shifting element 210 provides a reaction force on the energy transfer element 250 that is above a predetermined force limit.

[0207] This invention also includes a set of embodiments for a pedal-driven vehicle gear system.

[0208] ES1: A pedal-driven vehicle gear system 100, comprising:

[0209] Multi-speed gears 110 and 290 are configured to provide a varying gear ratio between gear input element 111 and gear output element 112; and

[0210] The control system 150 is configured to include the steps and features of any of the methods from EM1 to EM22.

[0211] In one alternative embodiment, the gear input element is configured to be driven by both the crank driver 130 and the motor driver 140.

[0212] In the above embodiments and figures, the control system has been disclosed as a single control system. However, this control system can be broken down into multiple sub-control systems. For example, the control system may include a shift sub-control system, a motor driver sub-control system, a torque sensor sub-control system, a battery management sub-control system, etc. In one embodiment, the main control system can receive shift control signals from the shift operator and transfer them to the shift sub-control system. The shift sub-control system can receive torque values ​​from the torque sub-control system and provide pre-rise, rise, and fall control signals to the motor driver sub-control system.

[0213] Figure 1 and Figure 2 Two different embodiments of the pedal-driven gear system of the present invention.

[0214] from Figure 1 Initially, the pedal-driven gear system 100 is an intermediate drive or crank drive, comprising a multi-speed shifting system 110 with a gear input element 111 and a gear output element 112. In this case, both the gear input and output elements are rotating shafts, but they can also be rotating cylinders, rotating sleeves, etc. The pedal-driven crank drive 130 drives the gear input element via a crank transmission. Furthermore, the electric motor 40 is also configured to drive the gear input element 111 via a motor transmission. In this case, the crank and motor transmission are chain drives. A one-way clutch (e.g., a wedge clutch) is used in the chain drive to prevent the motor from driving the crank and to prevent the crank from driving the motor.

[0215] The motor is controlled by the control system 150. Furthermore, the shift operator 170 is configured to transmit a shift control signal 172 to the control system to initiate a shift sequence. Upon receiving the shift control signal, the control system can transmit a first shift signal or a second shift signal 143, 144 to the shift actuator 121, wherein the shift actuator is configured to move a movable shift element configured to perform shifting in the multi-speed gear system. In this case, the movable shift element is a rotary shift element axially disposed inside the multi-speed gear system.

[0216] In addition, the control system is configured to transmit any combination of the pre-rise control signal 152, the rise control signal 153 and the fall control signal 154 to the electric motor driver.

[0217] The crank drive includes a crank torque sensor 131, wherein a crank torque signal 132 indicating the crank torque from the crank torque sensor is obtained by the control system. The control system further obtains a motor torque signal 142 indicating the motor torque from the motor drive.

[0218] Figure 2 This invention describes a pedal-driven shifting system according to an embodiment of the present invention. In this embodiment, a multi-speed gear 110 is disposed in the hub of a pedal-driven vehicle wheel 103. In this case, the gear output element 112 is the housing of the multi-speed gear, connected to and driving the wheel 103. A pedal-driven crank drive 130 drives the gear input element via a crank transmission. Additionally, an electric motor 40 is also configured to further drive the crank transmission via a motor transmission to drive the gear input element 111. In this case, the crank and motor transmission are chain drives, wherein the sprockets are coaxially disposed on the crankshaft of the crank drive. The crankshaft is unidirectionally connected to the crank transmission via a one-way clutch. The sprocket of the motor drive, coaxially disposed on the crankshaft, idles relative to the crankshaft and is unidirectionally connected to the sprocket of the chain drive via a one-way clutch (e.g., a wedge clutch).

[0219] Other features and Figure 1 Their corresponding features are similar.

[0220] Now refer to Figure 1 Or 2 combined Figure 3 , Figure 4 , Figure 5 and Figure 6Specific embodiments are described using combined timing / sequence and torque diagrams. It should be noted that the time scale t is for illustrative purposes only and does not represent a linear time scale. The primary purpose of the time scale is to illustrate the sequence of events and the corresponding torque response in the gear system. Therefore, unless otherwise explicitly stated, the time represented by the distance between two consecutive vertical dashed lines can represent a time interval from 0 to infinity.

[0221] Similarly, the purpose of torque scales is to describe relative torque values, and they must represent true values.

[0222] Figure 3 This invention describes a gear shifting method according to one embodiment of the present invention.

[0223] Figure 3 The upper part includes a timing diagram from top to bottom involving a shift operator 170, a crank torque sensor 131, a shift control system 150, a motor driver 140, and a shift actuator 121.

[0224] In the timing sequence, the control system 150 receives a shift control signal 172 from the shift operator 170. This can be triggered by the rider operating the shift operator.

[0225] Then, the rise control signal 153 is transmitted from the control system to the motor driver. This indicates the start of the rise torque time period tbT.

[0226] This will increase the torque contribution from the motor to the gear input element. This increased torque will give the input element a speed advantage compared to a crank drive that also drives the gear input element. Therefore, the torque contribution from the crank drive to the gear input element decreases, and the torque contribution from the crank is unloaded, as shown by the lower line in the gear torque / timing diagram.

[0227] Following the torque increase period, a torque decrease control signal 154 is transmitted from the control system to the motor driver to reduce the motor torque. When the control system receives the shift control signal, the total torque drops significantly below the initial total torque because the torque from the crank drive has been at least partially unloaded. The torque decrease control signal marks the beginning of the torque decrease period tdT.

[0228] As initially stated, a shift will only occur when the total torque of the entire gearbox is below the shift torque threshold STT. Figure 3 The shift point (STT) has already been indicated. It can be seen that when the control system initially receives the shift control signal, the total torque (i.e., the sum of the torque contributions from the crank drive and motor drive) is higher than the shift torque threshold. Therefore, shifting is impossible at that stage. However, during the torque reduction period, the total torque is much lower than the shift torque threshold, thus allowing a shift to occur.

[0229] In order to perform a gear shift, at the start of the torque reduction period or immediately after the reduction control signal, a second shift signal 144 is transmitted from the control system to the shift actuator, and then the shift can be performed as expected, regardless of whether the initial torque of the entire multi-speed gear was higher than the shift torque threshold.

[0230] Shift time depends on the shift actuator's shift capability, i.e., the actuator torque and speed. Even in Figure 3 Even when the total torque in a gear is close to zero, a shift torque is still required to change from one gear ratio to another. This may involve, for example, the axial, lateral, rotational, radial, and tangential movements of the clutch, connecting rod, and gear components in a multi-speed gear system.

[0231] For illustrative purposes, the shift time ts has been expressed as... Figure 3 However, it's understandable that shift times significantly impact the user experience of pedal-operated vehicles. More powerful actuators could reduce shift times. These actuators, however, require more power and involve increased size and weight.

[0232] Figure 4 Another specific embodiment of the invention is disclosed. (Compared to...) Figure 3 Similar to the illustrated embodiment, the control system transmits an up control signal 153, followed by a down control signal 154. However, in contrast to the aforementioned embodiment, the first shift signal 143 is transmitted from the control system to the shift actuator before the up control signal, instead of transmitting the second shift signal during the down torque period.

[0233] The shift actuator has an inherent shift delay in this case, which allows potential energy to accumulate in the shift actuator from the first shift signal 143 until the drop control signal, resulting in large torque and shortened shift time ts'.

[0234] Figure 4 The graph below illustrates the accumulation of potential energy in the actuator. The energy gradually increases from a minimum potential energy level to a maximum potential energy level. The curve representing the actuator's potential energy corresponds to the shift torque available when the potential energy is released. This shift torque corresponds to the actuator's shift torque threshold STT. In this embodiment, the shift torque threshold therefore increases until it reaches its maximum value during the rising torque time period tbT.

[0235] During the loading of potential energy, the actuator is always ready to perform a gear shift. However, because the total torque is higher than the shift torque threshold, the torque of the shift actuator is resisted by the total torque in the opposite direction, so a shift cannot occur until the total torque drops below the shift torque threshold. The shift occurs at the beginning of the torque reduction period tdT, and a large torque is available due to the energy stored in the shift actuator. This reduces the shift time and improves the user experience. To illustrate, Figure 4 The shortened switching time ts' is displayed at the bottom.

[0236] Figure 5 Public and Figure 4 In another specific embodiment similar to the one described above, but otherwise, the shift control system 150 receives or acquires a crank torque signal 132 representing the crank torque from the crank torque sensor 131 and a motor torque signal 142 representing the motor torque from the motor driver 140.

[0237] These two crank signals are used to calculate the total torque of the entire gear system (i.e., between the gear input element and the gear output element), and in this embodiment, they are used to determine the level of the rising torque bT.

[0238] Figure 6 Another specific embodiment is disclosed, in addition to Figure 5 In addition to the described features, a pre-rise control signal 152 is included, preceding the first shift signal 143, from the control system to the motor driver 140. Similar to the rise control signal, the pre-rise control signal is used to instantaneously increase the motor torque. The purpose of the pre-rise control signal is to ensure that the total torque is maintained and stabilized above the shift torque threshold when potential energy begins to be applied to the shift actuator, in order to prevent uncontrolled shifting in the initial stage of shifting, i.e., when the total torque to be offset is below the shift torque threshold.

[0239] exist Figure 6 In this case, the initial total torque calculated according to the above description is lower than the shift torque threshold, so the starting shift sequence is unsafe. Therefore, a pre-rise control signal is sent to the motor before the final rise control signal is sent to the motor to increase the total torque during the pre-rise time period pbT.

[0240] In one related embodiment, the pre-rise control signal is optional, and is not used when the initial total torque is higher than the shift torque threshold.

[0241] If the crank torque signal value is higher than a predetermined threshold, a feedback signal can be sent from the control system back to the shift operator to indicate that shifting is not possible. The feedback signal can be visual or tactile, such as a flashing light or a vibrating handle.

[0242] Because the total torque is below the shift torque threshold STT, the shift control system provides or transmits a pre-rise control signal 152 to the motor to operate at the pre-rise torque time period tpbT.

[0243] exist Figure 7 and 8 In one specific embodiment shown, the vehicle gear system 1 includes a movable shift element 10 configured to shift gears in the vehicle's multi-speed gear system. In this case, the shift element is a hollow shift shaft disposed within the gearbox. As the shift shaft rotates relative to the gearbox, the gear ratio of the gearbox changes according to the prior art.

[0244] Depending on the type of gear mechanism used within the gearbox, the shift shaft can interact with the gears of the gearbox via, for example, a clutch or a ratchet.

[0245] The gear system 1 also includes an energy source 20, which takes the form of an electric servo motor with a drive shaft arranged parallel to the shift shaft. The electric servo motor is powered by a battery and controlled by a control system.

[0246] An energy storage element 30, including a preloaded helical spring, is coaxially disposed inside the hollow shift shaft.

[0247] Further details of each of these elements in this particular embodiment are presented below.

[0248] The reduction gear is a single-input / single-output three-stage reduction gear, including a toothed first gear set and a second gear set 42, 43 between the motor shaft and the coil spring 31. The large-diameter gear 42a of the first gear set 42 meshes with the small gear 41 on the motor shaft. The first gear set includes a small-diameter gear 42b that meshes with the large-diameter gear 43a of the second gear set 43. Finally, the small-diameter gear 43b meshes with a large-diameter shift shaft gear 44 coaxially connected to the first end 34a of the sleeve 34.

[0249] The type of reduction gear has been selected to allow a small-sized and low-power servo motor to load (i.e., compress) the coil spring with sufficient potential energy in the first part of the shifting action, as previously described. If a larger servo motor is used, a smaller reduction gear, such as a double reduction gear or a single reduction gear, can be used. The coil spring is sized to compress the amount of two consecutive shifts. For example, if 10 degrees of rotation of the shift shaft represents one shift, and 20 degrees represents two consecutive shifts, then in this embodiment, the coil spring must allow 20 degrees of torsional compression during the load. However, if only one shift is required, the compression can be reduced. Similarly, three consecutive shifts require greater compression, but with the same servo motor and reduction gear, it also requires a longer loading time.

[0250] Sleeve 34 includes a helical spring. The first end of the sleeve is further directly connected to the shift shaft gear 44, and the sleeve rotates in a fixed proportion to the servo motor, which is determined by the gear ratio of the reduction gear.

[0251] The outer diameter of the second end 34b of the sleeve corresponds in cross-section to the inner diameter of the shift shaft, making the sleeve radially stable at its second end. At the first end of the sleeve, the sleeve and the shift shaft gear are radially supported by ball bearings 35 in the outer casing wall 2. The sleeve is locked longitudinally due to the narrowing of the inner diameter of the shift shaft.

[0252] The second end 31b of the coil spring pushes a transverse pin 32, which is also contained in the energy storage element and extends into longitudinal grooves 11a, 11b on the inner wall of the shift shaft 10. Therefore, the pin is fixed relative to the shift shaft in the rotational direction because the walls of the grooves prevent its rotation. However, the pin can move longitudinally along the grooves.

[0253] The energy storage element also includes a retaining member 33 disposed inside the second end of the sleeve. The retaining member has a guide protrusion extending into the second end of the helical spring.

[0254] The fixing member also has a transverse through hole for the pin.

[0255] The fixed component can rotate and move longitudinally inside the sleeve. However, these movements are limited by the compression of the pin and spring.

[0256] At the second end of the sleeve, a first through hole and a second through hole 35 and 36 are formed opposite to the pin. The positions of the through holes correspond to the positions of the pin when the coil spring is at its minimum compression.

[0257] From each through-hole, two notches 35a, 35b and 36a, 36b extend toward the first end of the sleeve in opposing helical or curved directions. The notches allow the pin to move relative to the sleeve in both longitudinal and rotational directions while constrained by the notches. The outer circumference of the notches allows the pin to rotate twice consecutively, i.e., if each rotation is 10 degrees as described above, then a rotation of 20 degrees is allowed.

[0258] When the sleeve is twisted in the first direction by the servo motor and the shift shaft is rotatably fixed by a reverse torque, the first end of the pin moves spirally or flexibly from the through hole 35 into the first cut 35a. The second end of the pin moves spirally or flexibly from the through hole 36 on the opposite side along the opposite first cut 36a.

[0259] When the sleeve rotates in a second direction opposite to the first direction by a servo motor and the shift shaft is rotatably fixed by a reverse torque, the first end of the pin moves from the through hole 35 in a curved or spiral manner into the second cut 35b. The second end of the pin moves from the through hole 36 on the opposite side in a spiral or curved manner along the opposite second cut 36b.

[0260] The coil spring is longitudinally locked at its second end by a retaining member, which is in turn locked to a sleeve by a pin. The end of the sleeve abuts a narrow portion of the inner diameter of the shift shaft. When the coil spring is in the locked position, the coil is preloaded by compression, and the pin cannot move from its initial position unless subjected to a torque sufficient to overcome the preload force.

[0261] The servo motor 20 is operably connected to the control system 50 and can be controlled via an undisclosed servo motor controller circuit for forward or reverse start and stop, as well as the speed of the servo motor.

[0262] The following will provide a step-by-step explanation of gear shifting.

[0263] Once the control system detects a shift request (e.g., shift control signal 172 from the shift operator), it transmits a shift signal 143 to the servo motor, which then begins to rotate the sleeve via the reduction gear. As long as the servo motor continues to rotate the sleeve, the torque exerted by the pin on the shift shaft increases.

[0264] As initially stated, the torque required to rotate the shift shaft from one position to the next depends largely on the rider's pedaling force and the drive motor 40.

[0265] Figure 11 The left side schematically illustrates how inherent hardware limitations in the gear system prevent shifting from occurring when the current shift torque threshold (STT) is exceeded, where the current STT is the maximum torque between gear input element 111 and gear output element 112 used to perform gear ratio changes in a multi-speed gear system. The current STT may vary between a minimum (Min) STT and a maximum (Max) STT, depending on factors such as temperature and component aging.

[0266] Figure 11 The right side schematically illustrates how the invention can be used for shifting even when shifting is impossible due to current STT limitations. The increasing / decreasing torque sequence and the energy storage element, described later, both contribute to this advantage individually or in combination.

[0267] Although the current STT is the actual hardware limitation of the gearbox, the set STT is still the value representing the current STT in the control system. Because we can assume that the new current STT can be increased above the maximum STT, the set STT can be set to the static value of the maximum STT, with an optional safety margin as shown in the figure.

[0268] Figure 12 An adaptive STT according to an embodiment of the present invention is illustrated by a flowchart. In one embodiment, the actuator torque is adjusted based on the shift success rate.

[0269] When the actuator torque increases due to a success rate lower than the predetermined success rate, Figure 11 The maximum and minimum STT shown, as well as the current STT, will increase, meaning that shifting can be performed with higher torque across the multi-speed gear set. However, if the current actuator torque results in excessively long shift times, the actuator torque may be reduced. The adaptation condition for the actuator torque can be the shift success rate, where the success rate can be a statistical value. Therefore, the actuator torque is adaptive in this case to balance shift success rate and shift time.

[0270] Another approach to balancing shift time and success rate is to adjust the set STT to reflect changes in the current STT caused by factors such as temperature variations or component aging. In this embodiment, the current STT is measured indirectly by measuring the shift success rate in the same manner as described above. If the success rate is higher than a predetermined threshold, the set STT is increased. This means that boost / dip sequences do not need to be executed as frequently as before, and any one of the pre-boost torque time period tpbT, boost torque time period tbT, or de-boost torque time period tdT can be shortened. On the other hand, if the success rate is lower than the predetermined threshold, the set STT is decreased. This means that boost / dip sequences will be executed more frequently, and any one of the pre-boost torque time period tpbT, boost torque time period tbT, or de-boost torque time period tdT can be increased.

[0271] The predetermined threshold can be implemented as a hysteresis with an upper and lower threshold, where the set STT increases when the success rate is above the upper threshold and decreases when the success rate is below the lower threshold. Similarly, the actuator torque can decrease when the success rate is above the upper threshold and increase when the success rate is below the lower threshold.

[0272] exist Figure 13 and 14In the specific embodiment shown, the vehicle shift actuator 201 is configured to rotate a movable shift element 210. Only one end of the shift element 210 is shown in the figure. However, in this embodiment, the shift element is a rotatable shift shaft, wherein the rotational position of the shift shaft determines the gear ratio of the multi-speed gear system. A multi-speed gear system using such a rotatable shift shaft is described in detail, for example, in WO20201230842A1.

[0273] Worm gear 211 is attached to the end of shift shaft 210. The worm gear can also be integrated with the shift shaft, but here it is attached to the end of the shift shaft by a spline coupling, which allows for easy installation and removal of the shift actuator and worm gear from the shift shaft.

[0274] The shift actuator includes a longitudinal energy transmission element 250 having a threaded first portion 51, which can be considered as a worm meshing with a worm wheel 211 in a worm drive.

[0275] The energy storage element 230 includes a frame 232, which may also be a housing for the energy storage element. The frame 232 is connected to the output of the energy source 220 (in this case, an electric motor) via a gear drive 240. Additionally, a threaded first portion 251 of the energy transmission element 250 extends from the frame and is rotatably fixed to it. Therefore, when the energy source rotates the frame 232, the threaded first portion 251 rotates with the frame, causing the worm gear 211 and the shift shaft 210 to rotate, thereby changing to a higher or lower gear ratio. Here, rotation in one direction changes to a higher gear, while rotation in the opposite direction changes to a lower gear.

[0276] To ensure shifting even under conditions of high reverse torque, this embodiment includes... Figure 16 Some additional features that can be seen in the middle, Figure 16 yes Figure 14 and 15 The details (more specifically, the cross-section of the energy storage element 230 and its internal components) are shown.

[0277] As previously described, the energy storage element 230 is configured to be loaded with potential energy from the energy source 220. In this embodiment, the energy storage element includes an elastic element 231 in the form of a compression spring, which is held in a balanced position between first and second end stops 236a, 236b of the frame 232. The first end element 234a is disposed between a first end of the spring and the first end stop 236a. Similarly, the second end element 234b is disposed between a second end of the spring and the second end stop 236b. The first and second end stops are in the shape of washers.

[0278] The first and second end elements 234a and 234b, as well as the first and second end stops 236a and 236b, all have through holes, wherein the through holes of the first and second end stops 236a and 236b are larger than the through holes of the first and second end elements 234a and 234b.

[0279] Energy transfer element 250 extends through or partially through these holes. More specifically, a third portion 253 of energy transfer element 250 extends through elastic element 231 and first and second end elements 234a, 234b, and the diameter of the third portion 253 is slightly smaller than the inner diameter of the holes of the first and second end elements 234a, 234b to allow them to slide along the third portion 253. At each end of the third portion, the diameter increases to a value greater than the holes of the first and second end elements 234a, 234b, but equal to or less than the inner diameter of the first and second end stops 236a, 236b, such that energy transfer element 250 can move longitudinally inside the frame 232.

[0280] The elastic element 231 is preloaded (i.e., precompressed) within the frame 232. A certain force is required to overcome the preload in order for the energy transfer element 250 to move in one or other directions.

[0281] A second part 252 is rotatably fixed between the third part 253 and the first part 251 of the energy transfer element 250, but this second part is axially free relative to the frame 232. That is, the second part 252 rotates together with the energy storage element 230 while still being able to move longitudinally. This is achieved by a spline connection, wherein the second part 252 has an external longitudinal spline, and the inner diameter of the corresponding part of the frame has a corresponding internal longitudinal spline.

[0282] The frame 232 is rotatably supported by a first rotary bearing 255. In addition, one end of the energy transmission element 250 is rotatably and longitudinally supported by a sliding bearing 256.

[0283] In addition, the energy storage element 230 includes magnets in its sidewalls, thereby allowing a magnetic sensor configured in the housing and connected to the control system to detect the completion of each full rotation so as to control the electric motor to stop when the requested number of revolutions for shifting is reached.

[0284] Reference Figures 17a to 17b Further explanation of the function of the shift actuator.

[0285] First, consider the elastic element being in such a position as Figure 16 The equilibrium position is such that the force acting on the energy transmission element 250 must overcome the preload on the elastic element in order to move the transmission element longitudinally.

[0286] It is also considered that, in the first case, the shift shaft 210 can be rotated with minimal torque for shifting, i.e., the reverse torque from the shift shaft acting on the energy transmission element via the worm gear drive is less than the preload of the elastic element 231. When the electric motor rotates the energy storage element 230, the energy transmission element 250 and its first part as the worm also rotate. The rotating worm acts on the worm wheel 211 and the shift shaft 210. Therefore, the rotation of the shift shaft is proportional to the rotation of the energy storage element 230 and also proportional to the rotation of the motor shaft that drives the energy storage element via the gear drive 240.

[0287] The direction of rotation of the shift shaft depends on the direction of motor rotation.

[0288] The actual angle of rotation of the shift shaft 210 required to shift from one gear to the next depends on the geometry of the gear system itself. In any case, for a multi-speed gear system, continuous rotation generally means that multiple gear changes can be performed sequentially as the energy storage element 230 continues to rotate. For example, in a seven-speed system initially in first gear, the second, third, fourth, fifth, sixth, or seventh gear can be selected by rotating the energy storage element in a single direction. For any single or multiple gear changes in the opposite direction, the energy storage element 230 rotates in the opposite direction.

[0289] Now back Figure 17a This illustrates a different scenario where the intention is to rotate the shift shaft 210 counterclockwise to shift gears once or multiple times. However, because the reverse torque on the shift shaft is relatively greater than the preload of the elastic element 231, the elastic element is further compressed by the upper end of the energy transmission element 250 and the first end element 34, as the energy storage element 230 and the energy transmission element 250 rotate and the threaded first portion 251 climbs up the worm gear resisting rotation.

[0290] Figure 17a The final positions of the energy transmission element 250 and the elastic element 31 are described below. It should be noted that the elastic element at this position is already loaded with potential energy, and the force acting on the energy transmission element in the upward direction is much greater than the preload force at equilibrium. Therefore, if at any time from the equilibrium position to the final position, the absolute value of the increased upward force on the energy transmission element exceeds the absolute value of the downward force acting on the energy transmission element due to the reverse torque on the shift shaft, the shift shaft will be forced to rotate in the expected counterclockwise direction, and the energy transmission element will return to its equilibrium position.

[0291] If the force from the energy storage element is still insufficient to overcome the reverse torque, a shift will only be performed after the torque on the shift element is reduced to a value that allows for shifting.

[0292] If you intend to switch to more gears in the same direction, the energy storage element should be configured according to the above. Figure 16 and Figure 17a The situation continues to rotate.

[0293] Figure 17a The energy transmission element 250 is illustrated in a terminated position, for example, because it has reached the end of the worm gear drive and cannot move further downward longitudinally. The terminated position may correspond to a fixed number of gear shifts, such as first, second, or third. For example, if the terminated position corresponds to two gear shifts and the control system only requests one shift, the rotation of the energy storage element 230 should stop immediately before the terminated position of the energy transmission element 250, reaching the number of revolutions required for one gear shift.

[0294] Figure 17b To illustrate another scenario, in which the rider intends to move clockwise (i.e., with...) Figure 4 (c) Rotate the shift shaft in the opposite direction to the previous situation. Since the reverse torque on the shift shaft is relatively greater than the preload of the elastic element 31, the energy storage element 230 and the energy transmission element 250 rotate and the threaded first part 251 climbs up the worm gear resisting rotation. The elastic element is further compressed by the lower end and the second end element 234b of the energy transmission element 250.

[0295] from Figure 17a The description can be used to understand the rest of the situation, except that the forces act in opposite directions.

[0296] Figure 15 Another embodiment of the invention is described, wherein the shifting element 210 is one or more pawls or notches that move laterally in the gear to engage and disengage gears in the internal gears. The actual type of the internal gears is not important to the invention and is therefore not shown in the drawings. However, it is understood that the gear system has a housing 200 through which the main shaft 213 extends, wherein the main shaft can be fixed to the vehicle frame. The input and output elements of the gear system are not shown, but typically an input shaft can be coaxially and rotatably configured outside the main shaft, and the housing itself can be directly connected to the output element and rotate relative to the main shaft and input shaft.

[0297] Here, the internal components and functions of the energy storage element 230 are the same as in the embodiments described above. The energy source and drive gear can also be the same. The main difference is that the energy transmission element 250 extends into the main shaft 213. In this case, a portion 212 of the energy transmission element and the internal components of the shifting element 210 have corresponding threads. Therefore, when the energy transmission element 250 is rotated by the energy source, the shifting element 210 moves laterally within the slot 211 in the main shaft, and moves the internal gear element 220 laterally and changes the meshing mode of the internal gears.

[0298] In the same manner as in the above embodiment, if the reverse torque from the internal gear element exceeds the preload of the elastic element, the energy storage element 230 will be loaded with potential energy. As the energy transmission element rotates, the force exerted by the shifting element on the internal gear element increases, and if this force increases at any time to exceed the force in the opposite direction due to the reverse torque, the internal gear element will move to perform a shift.

[0299] As Figure 15 In another alternative embodiment, the energy transfer element 250 can be divided into two parts, which are interconnected by a helical gear (e.g., a spur gear), which would allow the shift actuator to be conveniently configured on the vehicle.

[0300] In exemplary embodiments, various features and details are shown in combination. The fact that several features are described with respect to a particular instance should not be construed as implying that those features must be included together in all embodiments of the invention. Conversely, features described with respect to different embodiments should not be construed as mutually exclusive. Those skilled in the art will readily understand that embodiments comprising any subset of the features described herein that are not explicitly dependent on each other have been contemplated by the inventors and are intended to be part of the disclosure. However, an explicit description of all such embodiments would not aid in understanding the principles of the invention, and therefore some arrangements of features have been omitted for simplicity or brevity.

Claims

1. A computer-based method for operating a pedal-driven vehicle gear system, wherein, The gear system (100, 290) includes: - A multi-speed gear (110) configured to provide a varying gear ratio between a gear input element (111) and a gear output element (112); a crank drive configured to transmit torque to the gear input element; a motor drive configured to transmit torque to the gear input element; and a movable shifting element configured to shift the multi-speed gear between the gear ratios, wherein the method includes: - Receive a shift control signal (172) indicating that a shift should be performed. - Provide an upward control signal (153) to the motor driver to operate the upward torque time period tbT under the upward torque bT; and - A descent control signal (154) is provided to the motor to operate at a descent torque dT for a descent torque time period tdT, wherein the descent torque is higher than the descent torque. The gear system has a current shift torque threshold (STT), which represents the maximum torque between the gear input element (111) and the gear output element (112) for performing gear ratio changes in the multi-speed gear.

2. The method according to claim 1, wherein, The current shift torque threshold is within the range of being equal to or greater than the minimum shift torque threshold and equal to or less than the maximum shift torque threshold.

3. The method according to claim 2, wherein, The maximum shift torque threshold is a predetermined value based on the worst-case shift torque.

4. The method according to claim 2, wherein, The minimum shift torque threshold is a predetermined value based on the optimal shift torque, which includes at least one of the following: optimal operating temperature, the start of a maintenance period, and the break-in of gear assemblies.

5. The method according to claim 2, wherein, The maximum shift torque threshold and / or minimum shift torque threshold are specific to shifting.

6. The method according to any one of claims 1 to 5, wherein the method comprises: - Receive a crank torque signal (132) from the crank torque sensor (131), representing the torque difference between the crank drive and the gear input element; as well as - Receive a motor torque signal (142) from the motor driver, representing the torque difference between the motor driver and the gear input element, wherein - The sum of the rising torque and the crank torque from the crank torque signal is higher than the current shift torque threshold; as well as - The sum of the decreasing torque and the crank torque from the crank torque signal is lower than the current shift torque threshold.

7. The method according to any one of claims 2 to 5, wherein, The method includes: - After receiving the shift control signal and before providing a control signal to the motor to operate at the rising torque bT, a pre-rise control signal (152) is provided to the motor to operate at a pre-rise torque time period tpbT at a pre-rise torque pT, wherein the pre-rise torque is lower than the rising torque and higher than the falling torque.

8. The method according to claim 7, wherein, The method further includes: - Receive crank torque signal (132) from crank torque sensor (131), representing the crank torque as the torque difference between the crank drive and the gear input element; - Receive a motor torque signal (142) from the motor driver, representing the motor torque as the torque difference between the motor driver and the gear input element; - The total torque is calculated as the sum of the crank torque and the motor torque; and The pre-rise control signal (152) is provided only when the total torque is below the pre-rise torque threshold.

9. The method according to claim 7, wherein, The multi-speed gear includes shift actuators (121, 201, 202) configured to move the shift elements (10, 210), and the method further includes: - Before providing the up control signal to the motor driver (140), a first shift signal (143) is transmitted to the shift actuator.

10. The method according to claim 9, wherein the method comprises: - After providing the pre-rise control signal, the first shift signal (143) is transmitted to the shift actuator.

11. The method according to any one of claims 1 to 5, the method comprising: - Measure the success rate of a series of gear shifts; - If the success rate is higher than a predetermined high success rate threshold, increase the set shift torque threshold and / or decrease the actuator force / torque; and - If the success rate is lower than a predetermined low success rate threshold, reduce the set shift torque threshold and / or increase the actuator force / torque.

12. The method according to claim 9, wherein, The shift actuator includes: - Energy source (20, 220); and - Energy storage element (30, 230); The energy source is configured to load or charge the energy storage element with potential energy, wherein the shift torque threshold is determined by the potential energy, and the energy storage element is configured to move the shift element.

13. The method according to claim 12, wherein, The energy storage element is configured to move the shifting element in two opposite directions from its equilibrium position, wherein the energy storage element is neither charged nor loaded with energy from the energy source.

14. The method according to claim 13, wherein the method comprises: - Energy transfer from the energy source to the energy storage element begins at start time t0; as well as - The energy transfer ends after a predetermined time interval ts1 following the start time, or when the energy storage element has reached a specific position or rotation angle.

15. The method according to any one of claims 1 to 5, wherein, The gear input element is configured to be driven by both the crank driver (130) and the motor driver (140).

16. The method according to claim 1, wherein, After providing the up control signal, the down control signal is provided to reduce the total torque of the multi-speed gear to below the current shift torque threshold, at which the gear ratio of the multi-speed gear can be changed. The method also includes: A gear shift is performed when the total torque drops below the current shift torque threshold.

17. A data processing and control system (150), comprising: One or more processors for performing the method according to any one of claims 1 to 16.

18. A computer program product comprising: A plurality of instructions, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 16.

19. A computer-readable medium comprising: A plurality of instructions, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 16.

20. A pedal-driven vehicle gear system (100), comprising: - A multi-speed gear (110, 290) configured to provide a varying gear ratio between the gear input element (111) and the gear output element (112); and - A control system (150) configured to implement the method according to any one of claims 1 to 16.

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