Tribology Performance Optimization Of Filtering Driving Mechanism

This research is funded by the State Natural Sciences Foundation Monumental Projects of 2007:"Reliability design method and theory of new type high performance transmission parts and system"(50735008/E0512). Filtering gear reducer (Patent Number: CN1699793) is developed by Professor Wang Jiaxu and Liang Xichang to conquer disadvantages of harmonic gear reducer and RV reducer and satisfy the requirements of reducer in space environment, such as high accuracy, high reliability, big torque, low power loss, small volume, light weight and so on. This paper aims at promoting the reliability, reducing the friction loss and prolonging the service life of the high performance electromechanical driving mechanism (Patent Number: CN101039053), which is invented by professor Wang Jiaxu and others from the state key lab of mechanical transmission of Chongqing university, by studying the tribological behaviors of its'key transmission unit. The major works in this paper are listed as follows:①By analyzing the structure of high performance electromechanical driving mechanism and the transmission principle of its key transmission unit, the main tribological behaviors occurred in filtering gear reducer are defined. Tribological behaviors of filtering gear reducer mainly include rolling and sliding friction of gear pairs, meshing impact between gears, rolling and sliding friction among rolling balls, inside track of dual gear and eccentric shaft, and friction loss of the lubrication oil piled out from the gear surface.②Solid models of key transmission parts of filtering gear reducer was built up and dynamic contact finite element analysis of the gear pairs was carried out. According to them, dynamic distribution of contact stress and Von Mises stress were defined and sliding situation of tooth surface was analyzed. The results indicate that the most serious sliding is arisen at tooth tip of dual gear.③Sliding friction loss calculation method of planet inner gear transmission was researched. In addition, the calculation formula was derived and sliding friction loss of filtering gear reducer was calculated.④The cause of contact impact between gears is analyzed and the meshing impact and scrape sliding occurred in filtering gear reducer is studied in this paper.. Based on the analysis, it can be found that the serious sliding phenomenon of dual gear tooth tip is caused by the scrape sliding which happened at the tooth root of output gear.⑤To avoid meshing impact, lighten sliding of gear tip and improve tribology capability, profile modification was carried out and modification parameters were is confirmed. Performance variety was compared between modification and non-modification gears by finite element simulation.