Torque Dynamic Characteristics Of Dry Clutch Assembly Based On Inversion Of Thermal Boundary Conditions

The occurrence of dry clutch slippage failure under severe conditions not only causes inconvenience to users but also results in economic losses of over 80 million claims per year in the clutch industry.This has become a crucial problem that requires a solution.The clutch slippage is directly related to its torque transmission capacity,which is affected by hightemperature deformation experienced under severe operating conditions.In order to improve the accuracy of torque calculation,this paper proposes a high-precision torque simulation calculation method based on a temperature field correction model that employs three different thermal boundary conditions inversion and sequential decoupling of multi-physical fields.The main research contents and conclusions are presented as follows:(1)Temperature field inversion and correction method based on three different thermal boundary conditionsThe paper establishes a modified temperature field inversion model based on three different thermal boundary conditions and a correction method.The temperature difference between the simulation and test is less than 10℃ at any time,with a temperature difference of less than 5℃ at the last moment of single-junction separation.The loading time and range of different thermal boundary conditions serve as correction variables.The results show that the temperature deviation of the modified temperature field inversion model is within 10℃,with more than 80% of the temperature deviation less than 5℃.(2)Calculation method of torque simulation based on the sequential decoupling of multi-physics fields of the temperature field inversion modelBased on the modified temperature field inversion model and considering the dynamic change of friction coefficient with temperature,the paper establishes a torque simulation calculation method that includes temperature field,deformation field,and pressure field by using one-way sequential decoupling.The results show that the torque values calculated by this method are within 10% of the test deviation,meeting the requirements of engineering simulation accuracy,and can be used for subsequent studies of torque-related characteristics.(3)Research on the influence law and dynamic characteristics of dry clutch torque transmission capacityThe paper investigates the influence of friction coefficient,compression force,and initial temperature on the clutch torque transmission capacity using single-factor and orthogonal test methods,respectively.The results show that for a single engagement and disengagement in the initial state,the weight of the influence on the torque transmission capacity is: compression force > friction coefficient > initial temperature.Each 10% increase in the above single factors corresponds to an increase in peak torque of 301N·m,223 N·m,and about 1.8 N·m decrease,respectively.The paper then studies the clutch torque dynamic characteristics by changing the heating rates using the above torque simulation curve.The results show that the structure is less affected by thermal deformation below 240°C,and the torque transmission capacity at this stage is mainly affected by the compression force and friction coefficient.The torque transmission capacity increases with an increase in compression force and friction coefficient.The structure is more affected by thermal deformation above 240°C,leading to a gap in the friction pair.The friction coefficient of the material at high temperature decreases significantly,and the torsional transfer capability is mainly affected by temperature at this stage.The higher the temperature,the smaller the peak torque,and the worse the torsional transfer capability.In conclusion,the proposed high-precision torque simulation calculation method based on three different thermal boundary conditions inversion and sequential decoupling of multiphysical fields provides an effective solution to the problem of dry clutch slippage failure.The method improves the accuracy of torque calculation and provides a theoretical basis for the development of new clutch products to reduce slipping failure,thereby reducing economic losses in the clutch industry.