Numerical Simulation Of Temperature Field And Experimental Study On Separate Steel Disc Of Wet Clutch

With the continuous development of auto industry,people’s requirements for the power and comfort of the automobile are getting higher and higher.The dual clutch transmission has gradually developed with the advantages of non-stop power,high transmission torque and high transmission efficiency.As its main parts,the wet dual clutch plays an important role,while the ablation of friction pair especially steel disc is serious in actual operation.It is the ablation that has become a major problem restricting its development.This paper conducts a series of researches on this issue,and the main work is as follows:In this paper,the clutch friction pair with radial groove is taken as the research object,the formation mechanism of friction pair ablation is revealed by the analysis and research of the circumferential temperature distribution of friction pair.The basis and suggestions for clutch optimization are provided from the influence of different parameters on the temperature distribution of friction pair.The temperature measurement of steel disc is carried out by the clutch bench test,the results are analyzed and the accuracy of the temperature model are verified.This paper expounds the power transmission and working principle of transmission and wet dual clutch,divides the clutch engagement stage into three stages from different lubrication state,torque and pressure change curve of friction pair,analyzes the fishbone diagram of the ablation problem of clutch friction pair,and sums up the causes of ablation into internal and external factors.The thermal characteristics of clutch friction pair are analyzed,and the analysis model of friction pair is established to lay a foundation for numerical calculation.The heat transfer mode,heat conduction,heat convection and heat radiation are introduced.The heat generation and cooling rate formula of friction pair are calculated,and the heat distribution mode is determined.Taking the radial groove friction pair as the research object,the circumferential analysis model of non-uniform contact is established,and the differential equation of heat transfer and the boundary conditions are determined.The finite element transformation of the differential equation and the programming of numerical calculation are carried out.The temperature results are output.The temperature rise and temperature distribution of the friction pair under the general starting conditions of the automobile are simulated.It is found that the temperature of the friction pair increases first and then decreases,and there is a temperature difference in the circumferential direction.If the friction continues,the continuous temperature rise in the high-temperature area will cause the friction pair to be ablated.With different contact ratio,steel disc thickness,sliding speed and sliding time,the influence on the temperature distribution of friction pair is studied,which provides the basis for the optimal design of clutch.The clutch bench test is arranged and carried out,the test system and its components are introduced,and the steel disc temperature measurement is carried out by means of embedded thermocouples.It is found that the temperature of the measuring points at different radial positions is greatly different,and the temperature of the outer diameter > the temperature of the middle diameter > the temperature of the inner diameter,which conforms to the empirical formula for calculating the heat of the friction elements.The temperature of the friction pairs at the same circumferential position is different.The temperature change of steel disc under different flow rate of lubricating oil is quite different.Compared with the simulation results,the accuracy of the temperature numerical calculation model is verified.