Investigation On Lubrication Performances And Thermal Characteristics Of A Tapered Roller Bearing

Tapered roller bearings are widely used in automobile transmission,which can bear large radial and axial loads,reduce the noise of the transmission,simplify the structure of the transmission and increase the life of the transmission.During the working process,heavy load and improper lubrication make the tapered roller bearing skidded,which made the friction heat increase rapidly,and the heat could not be released in time and effectively,resulting in the burning of the surface of the bearing parts.Also the burning making the bearing to failure and affecting the normal work of the transmission.Jet lubrication is an effective lubrication method to lubricate the tapered roller bearings used on transmission with large loads.Therefore,ensuring the good lubrication and cooling of the tapered roller bearing during the working process is of great significance to improve the reliability and service life of the transmission.In this paper,the lubrication performance and thermal characteristics of the tapered roller bearing on the output shaft of a DCT transmission are studied by numerical simulation.The work and main conclusions are as follows:(1)Based on the geometric parameters of the tapered roller bearing on the transmission shaft,the fluid domain model of the bearing is established and the ANSA software is used to mesh the model.Then the fluid domain model of the tapered roller bearing is simulated and analyzed in the Fluent software,and the simulation method is verified.In order to get a suitable number of grids,the mesh independence of different number of mesh models is studied.(2)The roller of tapered roller bearing includes rotation and spinning.In the simulation of the two phase flow in the fluid domain of the tapered roller bearing,the simulation results are compared when considering or not considering the roller's spinning.It is found that the simulation results are more reliable when the roller's spinning is taken into consideration.The influence of different parameters,such as the rotating speed of the inner ring,the amount of oil injection and the number of nozzles on the lubrication performance of the bearing,is studied.It is found that the oil volume fraction in the bearing fluid field increases first and then decreases with the increase of the rotating speed of the bearing inner ring,while the oil volume fraction increases with the increase of the amount of oil injection and the number of nozzles.(3)A fluid solid coupling composite heat transfer simulation model of tapered roller bearing was established,and the Fluent software was used to simulate complex heat transfer of the solid and fluid fields of the tapered roller bearing under different working conditions.During the simulation,the heat is added to the contact zone between the rolling body and the inner and outer rings.The contact zone moving with the motion of the roller and the contact width is calculated by the Hertz contact.According to the simulation results,it is known that the temperature distribution of the tapered roller bearing is not uniform,the temperature of the contact between the rolling body and the inner and outer ring of the bearing is high,and the temperature of the roller is higher than that of the inner and outer ring of the bearing.The maximum temperature of the bearing under different working conditions does not reach the maximum temperature that the bearing steel can bear,so the lubrication method used now can meet the cooling requirements of the bearing.