Research On Tooth Surface Wear Of Involute Spur Gear And Its Influence On Friction Characteristic

Gear transmission is widely used in ship,aviation,automobile and other modern mechanical engineering.In the working process,the existence of tooth surface wear will change the shape of tooth profile and affect the load distribution as well as lubrication condition of tooth surface,affecting the friction characteristics of tooth surface.At the same time,the tooth surface wear is also affected by the lubrication condition of tooth surface.In addition,the existence of tooth surface friction reduces transmission efficiency,accelerates gear wear and greatly shortens the life of gear.Therefore,it is of great academic value and significance to explore the wear under different lubrication conditions and its influence on the friction characteristics of tooth surface.In view of this,this paper takes involute spur gear as the research object,and applies theoretical modeling and numerical simulation analysis to study gear wear process and its influence on friction state.The main research contents are as follows:1)Firstly,the mathematical model of spur gear is established and the related parameters are calculated accurately.Then,the continuous meshing transmission process of gears is static,the involute tooth surface is planarized,and the involute tooth profile is discretized with equal arc length.Then,the tooth surface wear model is established based on Hertz contact theory and Archard's wear formula.The wear coefficients,sliding distances and contact pressures of points on the tooth profile are calculated respectively to simulate the wear depth of each point on the tooth profile.The results show that the wear depth at the root of pinion gear is the largest and that at the pitch point is the smallest.2)Based on the mathematical model of gear pair,the friction lubrication model of gear pair is established,and the lubrication state of gear pair under different operating conditions is discussed.The distribution law of friction coefficient and friction force on the tooth surface is obtained by calculating the relevant parameters,and the friction characteristics of the tooth surface are revealed.The results show that the distribution of time-varying friction coefficient on the tooth surface is closely related to the lubrication state,and the increase of rotational speed and the decrease of load contribute to the formation of lubricating oil film.3)Based on the wear and lubrication model,the friction characteristics of the tooth surface are analyzed by analyzing the changes of the related parameters after calculating the wear of the tooth surface,and the influence of wear on the friction characteristics is discussed.The results show that under different lubrication conditions,wear can aggravate the change of friction characteristics in gear double teeth meshing zone,and has little effect on single teeth meshing zone.4)At last,the running test is carried out on the electric power closed gear test bench.By observing the morphology of the worn tooth surface and monitoring the vibration signal,the test and simulation results are analyzed.The results show that the test results are in good agreement with the theoretical simulation.It provides guidance for the analysis of wear process and the influence of wear on the friction characteristics of tooth surface.