Abstract:In order to analyze the grease lubrication condition between cylindrical roller and slider groove of cylindrical roller tripod universal coupling,a numerical calculation model of linear contact thermal elastohydrodynamic grease lubrication was established based on Ostwald model.Combined with the steadystate operating parameters of the coupling,the multigrid method and columnbycolumn scanning method were adopted to solve the pressure,film thickness and average temperature rise of lubricating oil film.The effects of different angles between input shaft axis and output shaft axis,different input shaft rotation radius,different cylindrical roller radius,different initial viscosity and different rheological index on the thermal elastohydrodynamic grease lubrication characteristics of coupling were investigated.The results show that reducing the angle between the input shaft axis and the output shaft axis,reducing the radius of rotation of the input shaft,and reducing the initial viscosity of grease are beneficial to reducing the secondary pressure peak and average temperature rise,but the film thickness is reduced.Increasing the radius of cylindrical roller is beneficial to reduce the secondary pressure peak,average temperature rise and increase the film thickness.Increasing rheological index is beneficial to increase film thickness and reduce temperature rise,but secondary pressure peak is increased.Therefore,it is conducive to improving the lubrication characteristics of the coupling according to the actual working conditions by selecting a smaller rotation radius,appropriately reducing the angle between input shaft axis and output shaft axis and increasing the cylindrical roller radius,appropriately reducing the initial viscosity of grease and increasing the rheological index.