Research On The Dynamic Transmission Error Of Small Module Gear With High And Low Temperature

This subject is supported by the National Natural Science Foundation(NO.51275538) and the Shanghai Key Laboratory of Spacecraft Mechanism Fund Project(NO.SM2014B101). Precision small module gear transmission system is widely used in the aerospace machinery, instruments and other mechanical devices. High and low temperature in vacuum, alternating high and low temperature and other environmental conditions directly affect small module gear transmission jamming or backlash, which lead to higher requirements for their design and performance simulation. Therefore, the study of dynamic transmission accuracy of small module meshing gear pair under high and low temperature conditions is significant. In this paper, the finite element model is established by considering the factors such as high and low temperature, gear eccentricity error and its phase, so that simulations are carried out for studying the static transmission error and dynamic transmission error of small module meshing gear pair. The main research work in this paper can be summarized as follows:(1) The exact analytical formula of normal backlash of gear pair and the variation of backlash with or without gearbox(only gear pair) were derived under high and low temperature. Taking this change into account, the upper and lower tolerance of tooth thickness of gear were calculated in order to avoid getting stuck.(2) Establishing the finite element model of both gear pair and gear pair in gearbox in order to study the law of change of small module meshing gear pair under high and low temperature. Simulation results verify that finite element solution consistent with the theoretical value, but the variation of former with the change of temperature is nonlinear.(3) Considering the effect of the speed, load and high and low temperature on dynamic transmission error, the finite element model for dynamic contact problem of gear pair is established. The variation of the dynamic transmission error of small module gear under high and low temperature was studied. By considering the double eccentric error under constant load, dynamic transmission error in high and low temperature was compared with the theoretical static transmission error. When considering the double eccentric error of gear under variable load, the dynamic transmission error jumps when the direction of load changes and the jumping amounts decrease in high temperature and amplitude of dynamic transmission error also decrease.