Modification Research Of High-speed And Heavy-load Gear Based On Thermo-elastic Deformation

Gear transmission is one of the most common transmission type in the modern industry. With the rapid development of industrial technology, the requirement of the gear performance is higher and higher, for example, the gear transmission systems used in ships, wind power equipments, mining equipments and many other industries are required with large power, high rotation speed, long service life and so on. At this point the impact of temperature on the gear modification has to be considered.The subject of this paper is supported by the Foundation for Science and Technology Research Project of Chongqing'key technologies and industrialization of high-performance marine gearbox'(CSTC:2007AB3030). Based on principles of gear engagement, tooth contact analysis, tribology, theory of heat transfer, combining with analytical method and finite element method, the gear elastic contact, convective heat, temperature field and gear modification were studied for high-speed and heavy-load gear system. The research work presented in this paper can be summarized as follows:①Using Hertz contact theory and elastic contact finite element method, the contact pressure on tooth surface was analyzed. After calculating the relative sliding velocity between the tooth flanks according to the principles of gear engagement, the tooth surface friction coefficient was obtained, considering with the impact of gear tooth surface roughness, the input lubricant temperature and kinetic viscosity. The calculation of tooth surface heat flow was got with tooth surface contact pressure and above results. At the same time, tooth surface heat flow variation and related factors were analyzed.②Considering the gear speed, the effects of lubricant thermal conductivity, density, specific heat, kinematic viscosity and the standard cooling capacity of the gap in the process of cooling, a method to calculate the heat transfer coefficients on the gear surface and tooth flank under oil lubrication was obtained, and the size and distribution of the heat transfer coefficient was analyzed, of which the relevant factors were discussed afterwards.③The finite element model of bulk temperature of gear was established. According to the heat balance equation of bulk temperature, and the thermal boundary conditions, the bulk temperature of gear was solved by using ANSYS, the impact of relevant factors on bulk temperature distribution was discussed.④Combining the temperature field with elastic contact analysis, the thermal- structural coupled model of gear was analyzed, and thermo-elastic deformation of gear was calculated. Based on these, gear modification was researched to get the ideal gear modification curve.⑤According to above calculation methods, using Visual Basic as the platform, combining secondary development of ANSYS, the software suitable to calculate the temperature field and thermal elastic deformation of gears was developed to provide convenience and efficiency for gear modification technology in engineering.