Studies On The Transient Mixed Lubrication Of Involute Gears Considering Thermal Effect

In engineering practice, as a result of temperature rise, the impact load, surface roughness and other factors, the most of lubrication of machine parts are usually in areas of mixed lubrication work . In the paper the problem about transient mixed lubrication of involute spur and helical gears is researched, which is good at improving life of parts, performance and reliability, carrying out on the mixed lubrication model and etc.First, according to relationship of the drive and geometry in the spur gear, the issue of mixed lubrication is studied , Finishing the establishment of mixed lubrication model of the involute spur gear isothermal transient line contact. A complete solution has been obtained with considering the variation of entrainment velocity, equivalent curvature and dynamic load induced by the effect of one or two pairs of teeth engagement. Second, considering the effect of pressure and density and viscosity caused by temperature, a complete solution of involute spur gears of time-varying thermal mixed lubrication has been obtained by calculating energy equation and basic equations.In the third part, the involute helical gear's geometrical parameters and characters is analyzed in detail. Then the calculate equations that can invert actual helical gears' meshing parameters at either location into two inverse tapered rollers' geometrical parameters is received. The model of the helical gear of the time-varying isothermal EHL mixed lubrication was built. A pair of helical gear teeth meshing the different instantaneous isothermal EHL problem was studied, the corresponding connection between pressure line and contact line was Utilized to analyze the transient characters of the distributions of pressure and film thickness at either location, also analyze the transient changes of pressure and film thickness along the pressure line. The fourth part of this thesis the thermal mix lubrication problem of a pair of meshing helical gears' teeth at either location is calculated and analyzed and Compared with the isothermal mix lubrication, analyzing the transient characters of the distributions of pressure, film thickness and temperature at either location.