Wheel Hub Sensor Arrangement for E-Bike Motor Control
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Solution Overview
Problem
Existing solutions for controlling auxiliary motors in vehicles propelled by muscular strength, such as e-bikes, face challenges in detecting pedal rotation due to complex and costly wiring when the motor is integrated into the wheel hub, requiring reliable and inexpensive sensor arrangements.
Innovation Solution
A sensor arrangement is integrated into the wheel hub unit with a freewheel, using a ring magnet and Hall sensors to detect rotational motion, eliminating the need for complex wiring by positioning the sensor close to the motor within the wheel hub, allowing for a compact, secure, and cost-effective solution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the sensor is positioned far from the auxiliary motor (e.g., in the crank mechanism) to detect pedal rotation, then the motor can be integrated into the wheel hub unit, but complex wiring and electrical connections are required to transmit the sensor signal over long distances
Solution Approach 1:
The patent combines the sensor and auxiliary motor into the same wheel hub unit, eliminating the need for long-distance wiring. The sensor is integrated directly into the hub assembly where it can detect rotational motion of the freewheel or hub components, placing the sensing element in immediate proximity to the motor it controls.
Solution Approach 2:
The patent uses the freewheel mechanism as an intermediary element to transmit rotational information from the pedals to the sensor. The freewheel's rotation, which corresponds to pedal motion, directly drives the encoder or magnetic encoder wheel, providing a mechanical coupling that eliminates the need for complex electrical wiring over long distances.
2Adaptability or versatility
If the sensor and auxiliary motor are positioned far apart, then the motor can be integrated into the wheel hub unit, but the installation effort and complexity increase due to long signal transmission paths
Solution Approach 1:
The sensor and auxiliary motor are merged into a single integrated wheel hub unit assembly. This consolidation allows the entire system to be installed as one module, significantly reducing installation time and effort compared to separately mounting components and routing wiring between them.
Solution Approach 2:
The sensor, freewheel, and auxiliary motor are pre-assembled and tested as an integrated unit before installation on the bicycle. This preliminary assembly ensures proper alignment and functionality, allowing for quick installation by simply mounting the complete hub unit without requiring on-site wiring or alignment adjustments.
3Adaptability or versatility
If complex wiring is used to transmit sensor signals over long distances, then the motor can be integrated into the wheel hub unit, but the cost and reliability of the system decrease
Solution Approach 1:
The sensor and auxiliary motor are positioned in immediate proximity within the same wheel hub unit, eliminating long electrical connections. This shortens the signal transmission path to minimal length, reducing susceptibility to interference, connection failures, and signal degradation, thereby improving overall system reliability.
Solution Approach 2:
The patent uses magnetic fields and optical encoders to detect rotational position and motion, replacing the need for complex mechanical linkages and long electrical wiring. The magnetic encoder wheel rotates with the freewheel, generating electrical signals directly at the sensor location without requiring physical signal transmission over distance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This arrangement provides a reliable and inexpensive method for controlling the auxiliary motor, ensuring accurate detection of pedal rotation and direction, reducing installation effort and enhancing the reliability of the system by integrating the sensor and motor as a fully insertable module.
Implementation Method 1
A sensor arrangement is integrated into the wheel hub unit with a freewheel, using a ring magnet and Hall sensors to detect rotational motion
Data Source
AI summary
The present invention provides a sensor arrangement. The signal from the sensor is used to control an auxiliary motor of a vehicle propelled by muscular strength. The auxiliary motor is there integrated into a wheel hub unit of the vehicle. The wheel hub unit comprises a stationary axle and a hub rotatably mounted to the axle. According to the invention, the assembly comprises the sensor and a freewheel of the drive train, which is propelled by muscular strength, mounted rotatable relative to the axle, where the sensor is arranged such that it detects a rotational motion of the freewheel relative to the axle.