Research On Dynamic Torque Testing Of Totation Axis With High Speed

Transmission shaft and rotating partsas are the critical components of the driveline, theirtransmission efficiency highly effected the safety and reliability of the power machinery.Torque, which was one of the core dynamic parameters, was the typical index to measure theperformance of the mechanical transmission system. It was able to scientifically evaluate thetransmission performance and the power allocation of the whole powermechanicaltransmission by measuring the parameters of the torque of the rotating parts and so on, inorder to provide powerful technical supports for the development of all kinds of mechanicalequipment and the products quality inspection.Through the research of the domestic and foreign developmentsof torque testingatpresent situation, it revealed that the torque sensing had been positively explored at home andabroad, and reached a very high precision. But under the circumstance that shaft rotated at ahigh-speed, the electric brush was easy to have a bad contact, even fell off, due to the straingauge torque test method used a brush type collector ring power supply. Meanwhile,magnetoelastic and magnetoelectric methods might have the problem of test failure owing tothe strong vibration of the high-speed rotation.In view of the torque testwhich shaft rotated at a high speed, a new torque test methodbased on the disk capacitive transducer is presented in this paper. This test method mainlyused two groups of disk capacitive transducersand asmall phase difference measurementcircuit to realize the torque test of therotating shaft. The specific principle is as follows: thecapacitanceof the disk capacitive transducerchanged by the rotation of the rotating shaft, thischange was converted into a sinusoidal signalafter differentialpulse-width modulationcircuit,single-ended differential op-amp circuit, and low-pass filter circuit. And the torsionaldeformation of the rotating shaft was reflected at the phase difference of the two-road signalsreceived from two groups of disk capacitive transducers. The phase difference of thetwo-road sinusoidal signal was effectively measured by asmall phase difference measurementcircuit, designed by FPGA. The non-contact testing of the rotating shaft torquewassuccessfully realized by usingthe corresponding relation of the torque, torsional angle and thephase difference. By means of theoretical derivation, designof the testing program, functionalsimulation and field test, it was verified that this planshowed certain feasibility. This kind ofmethod that was put forward here provided the design basis and the validation method toimprove the dynamic performance of large power machinery.