Electric-assisted bicycle axle torque sensor and treadmill frequency sensor system

Abstract

The invention discloses an electric-assisted bicycle axle torque sensor and a treadmill frequency sensor system; through this system, the moment of the middle axis, speed and direction can be measuredaccurately and sensitively; in this system, a planetary gear that transmits torque, the outer ring of the sun gear of a planetary wheel is pedaled on the central axis, according to the deceleration ratio. This moment acts on the elastic element with strain gauge. Four strain gauges are attached to the elastic element to form a full bridge circuit. The position of the strain gauge is determined byfinite element analysis. When the elastic element is subjected to the force on the central axis, the strain gauge resistance changes, the output voltage changes, and the real-time moment can be judged by the output voltage. The rotational speed and direction of the system are realized by Hall effect, so the positive and negative reversal can be judged by judging the phase difference of the waveform of adjacent gears. The sensor of the invention has the advantages of high sensitivity, stable signal, less process consumption and higher precision.

Description

technical field [0001] The invention relates to an electric assist bicycle, in particular to a central axis torque sensor and a cadence sensor system of the electric assist bicycle. Background technique [0002] At present, after the wheel hub motor and battery are installed on the bicycle, the power output of the motor is adjusted by hand controlling the electronic handlebar. The electric power-assisted bicycle means that the motor power is started only after the human pedal is pedaled. When the pedal stops, the output of the motor stops immediately, and the power of the motor generally changes with the change of the pedaling torque, so as to realize the intelligent control of the power of the motor. High-end electric bicycles generally need to be equipped with torque sensors and cadence sensors. [0003] Power-assisted bicycles are mainly divided into two categories. One category uses a mid-mounted motor, which has become the mainstream in the international market, such a...

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Problems solved by technology

[0004] The two patents CN201410047113 and CN103879506A of Tongsheng Vehicle Industry Co., Ltd., and the two patents of CN201310048472 and CN103085932B of Bafang Motor Technology Co., Ltd., both install torque sensors on the center shaft sleeve. The problem brought about by this design is the structure of the center shaft Complicated, the guarantee of fatigue strength is risky, etc.

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