| According to incomplete statistics, the friction consumes about more than one-third of the energy, and the wear resulted in more than 70% of the equipment failure. In recent years, people pay more and more attention to the fundamental principles of friction and combined with the actual industrial production, this article research is based on that.This paper first introduces the basic principle of friction and wear related,on the basis above,designs different testing schemes to study the influence law of different parameters on the coefficient of friction and weight order. And then establishes two-dimensional and three-dimensional models of the pin-disk friction pair, to observe the distribution of contact stress and the influence of load on the contact stress. Finally,according the friction and wear me chanism to research the drum brake provided by Yangzhou Yuanfeng Electromechanical Co. Ltd, mainly include tribology design of lining fixture and drum friction plate parameters optimization.The main content of the thesis research and the results are as follows:Firstly, using the MMW-1A and MMS-2A friction and wear testing machine,to design the test to detect the influence law of velocity and load on friction coefficient, and according to the orthogonal test to complete the speed, load, time affect the significant order of friction coefficient.Experimental results show that the friction coefficient has a tendency to decrease with the increase of load, speed, the influence degree of the order is load, speed, time. This has laid a theoretical foundation for the following research work.Secondly, in the finite element software Ansys,establishes static and dynamic model of pin disc pair, and then simulation analysis was carried out on the contact stress. The simulation results show that the distribution of contact stress is small in the middle while large in the edge,after the pin on disc sliding,contact stress field has the deviation to the sliding direction,pin bottom edge has maximum value,and the stress value increased. In addition, through the establishment of three-dimensional model of the analysis of the effect of load on the contact stress,found the contact stress values increase with the increase of load,the distribution status hasn’t changed.The finite element analysis can be intuitively observed contact stress distribution, but also provided way for the study on the mechanism of friction and wear.Thirdly, according to the shape of the friction plate to design fixture, respectively from the positioning and clamping into consideration,determines the main body of fixture and clamping device,and then the simulation analysis is the maximum offset 0.000197 mm, maximum stress 1.09 Mpa,meets the requirements. This analysis can reduce the error of manufacturing, ensure the assembly accuracy.Fourthly,using Solid Works to establish the geometric model of drum brake,and to import Ansys Workbench,analyzes the friction plate stress distribution under different conditions,completes optimization design of the material,the starting angle,the thickness of the lining.The results show that when the friction plate material is less metal,the thickness is between3 mm and 5mm,the starting angle is between 25 degrees and 27 degrees, the concentration degree of contact stress is reduced,and the volatility is relatively stable. This can provide good braking performance and increase the service life.The optimization parameters can provide data support for the development of new drum brake. |
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