Torque sensor and electric power-assisted bicycle

Abstract

The invention provides a torque sensor and an electric power-assisted bicycle. One end of an output shaft is concentrically fastened on a BB shaft, and the other end of the output shaft is connected with a free circumference of a load and is in sliding fit with the BB shaft; the strain gauge is attached to the output shaft; and a primary side coil and a primary side PCB which are in circuit connection are arranged on the primary side coil frame, a secondary side coil and a secondary side PCB are arranged on the secondary side coil frame, after alternating current with fixed frequency is supplied to the primary side coil, the secondary side coil generates induced current, and the output shaft and the secondary side coil frame rotate along with rotation of the BB shaft. According to the invention, a non-contact wireless power supply mode is adopted to solve the power supply problem of dynamic torque measurement. The torque signal is collected by detecting the torque signal change according to the principle that the load change of the secondary side can cause the current change of the primary side coil. The torque can also be detected in the mode that the primary coil and the secondary coil only play a power supply role, the secondary PCB is provided with the wireless transmitting unit to transmit signals wirelessly, and the primary coil receives the signals.

Description

technical field [0001] The invention relates to the field of motor drive, in particular to a torque sensor and an electric power-assisted bicycle. Background technique [0002] In the prior art, riding an electric-assisted bicycle using a torque sensor feels comfortable, easy, smooth, and easy to follow, and has excellent climbing performance against the wind. The major advantage of torque-assisted cycling is environmental protection and energy saving: due to the participation of manpower, it reduces Electric energy consumption of the lithium battery, the limited energy source in the vehicle. Compared with pure electric drive, under the same cruising range, the battery capacity can be reduced by half, and the required power, weight and cost of the motor can be greatly reduced. Based on the above, there are several typical methods of torque sensing currently used: [0003] (1) Installed on the center shaft, use torque to generate axial displacement, and use Hall to detect a...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to utilize strain gage, adopt slip ring to supply power to strain gage, adopt the torque sensor of slip ring output signal, this sensor has following problem to need to solve: slip ring and electric brush friction power supply and Acquisition of signals may easily cause fluctuations in the collected signals, and fluctuation signals with malfunctions may be generated.

Due to the use of collector rings for power supply and signal acquisition, the durability is not good. After a long time of use, there will be wear or wear powder, which will easily lead to signal distortion.

It has high requirements on the environment, and it is difficult to achieve waterproof and dustproof between the collector ring and the movement of the brush rotation process.

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