Wear Analysis And Tooth Profile Optimization Of Micro Gears With Rough Tooth Surfaces

Micro planetary gear train is an important transmission component in the micro electro mechanical system(MEMS),and its teeth performances directly affect the MEMS′s reliability and stability. At present, the micro gear′s tooth wear which under the consideration of the surface attractive force is relatively rare, but after a lot of analysis of cases, people find that the micro gear′s failure is usually caused by adhesion wear. Asperities on rough tooth surface have great effect on micro gear′s adhesive wear, but the specific influences there are no qualitative conclusions, therefore the research about micro gear′s tooth wear that under the consideration of the surface attractive forces, and propose some measures to decrease the tooth wear is very important.The asperities will result in high local stresses during the contact between rough tooth surfaces that are different from the contact between smooth surfaces, which accelerate the wear on tooth surfaces. In this paper, the adhesive wear in micro gear′s rough tooth surfaces are analyzed by two phases, and propose some measures to reduce the wear, on the other hand, the optimization of involute profile based on the deviation function is introduced. The main work is as follow:1Using archard wear formula, combine with JKR adhesive contact mechanics theory and GW statistical models of asperities, establish a rough tooth surface′s wear numerical simulation model which is under the consideration of the surface attractive forces.2On the basis of the tooth surface′s wear simulation model, a analysis under different parameters that are on the rough tooth surface is carried out, and obtain qualitative influences of various parameters on the wear of tooth surface, on the other hand,put forward some measures to improve the tooth wear.3Starting from tooth profile,propose a new method based on the deviation function to optimize the involute tooth profile. By the constrains of micro gear′s tooth surface contact stress, tooth surface′s sliding coefficient, tooth surface′s wear depth and bending stress etc. to get the optimal offset value.4On the basis of the optimal offset value, the optimized micro gears′ tooth profiles and the corresponding involute tooth profiles are contrasted, and tooth performances are also compared undering the two?dimensional JKR contact theory.The results showed that the optimized micro-gears′ tooth performances have greatly improved and its allocations are also more rational.