A system and method for testing the friction force of harmonic gear transmission tooth surface based on photoelastic patch method

Abstract

The invention discloses a harmonic wave gear transmission tooth surface frictional force test system based on a photoelastic coating method. The harmonic wave gear transmission tooth surface frictional force test system comprises an optical path incident system, a harmonic wave system and an optical path collection system; the optical path incident system consists of a guide rail, a light source, a lens and a polarization lens; the harmonic wave system consists of a photoelastic paster, a motor, a coupling, a harmonic wave decelerator and a brake; and the optical path collection system consists of a guide rail, a glass plate, an analyzer, a compensating gage and a camera lens. The harmonic wave gear transmission tooth surface frictional force test method adopts polarized light to irradiate the photoelastic paster fixed on an end surface of a gear tooth to be measured; interference fringes are formed after the polarized light is reflected by the paster surface and the gear end surface; the polarized light is captured by the camera lens after going through the polarized lens and the compensation gage; the magnitude and the direction of the tooth surface friction force and the distribution of the tooth surface friction force along the tooth surface at any meshing position can be obtained through calibration and calculation; and accuracy of measurement and calculation is depended on the type of the compensating gage and the thickness of the photoelastic paster. The harmonic wave gear transmission tooth surface frictional force test system and method of the invention not only adapt to harmonic wave decelerators of various models, but also analyze an impact caused by parameters like a load, input rotation speed, etc, on the tooth surface friction force.

Description

technical field [0001] The invention belongs to the technical field of harmonic gear transmission testing, and in particular relates to a harmonic gear transmission tooth surface friction testing system based on a photoelastic patch method and a testing method using the system. Background technique [0002] Harmonic gear transmission has been widely used in aerospace and robotics due to its advantages of light weight and large transmission ratio. Since the harmonic gear transmission has the characteristics of multi-teeth meshing, the friction in the transmission process mainly comes from the meshing area of ​​the gear teeth. Friction causes great harm to the transmission performance of harmonic gears: on the one hand, friction causes most of the energy loss in the transmission process of harmonic gears; on the other hand, the stiffness hysteresis induced by friction and system flexible coupling further reduces harmonics The output accuracy of the gear transmission. Therefo...

AI Technical Summary

Problems solved by technology

However, none of the above four methods can be directly applied to the test of tooth surface friction of harmonic gear transmission.

First of all, the resistance strain gauge is not easy to fix on the tooth surface of the tiny flexible spline, and its peripheral circuit is also difficult to design; secondly, the equivalent torque method calculates the friction coefficient of the tooth surface by measuring the torque loss of the whole transmission system, but for For harmonic gear transmission, the friction between the inner area of ​​the flexible bearing of the wave generator and the contact area between the outer ring of the flexible bearing of the wave generator and the flexible spline is also the cause of the torque loss of the system, so the accuracy of the calculation results obtained by this method is limited. In addition, even if it is assumed that the energy loss of harmonic gear transmission comes from tooth surface friction, due to the existence of multi-teeth meshing in the process of harmonic gear transmission, the variation law of friction force on a single tooth surface cannot be obtained; again, the equivalent gravity pendulum method It is often used to test the friction of tooth surfaces under static or quasi-static conditions, and the gravity pendulum is not easy to hang on the teeth of extremely small flexible splines or rigid splines; finally, since rigid and flexible splines do not have photoelastic materials, the photoelastic method also inappropriate

Due to the above-mentioned difficulties in the tooth surface friction test of harmonic gear transmission, there is no mature testing technology for tooth surface friction of harmonic gear transmission at this stage

Images