| This paper takes a BMW wheel-to-wheel electronically controlled Multi-Slip limited differential as the research object,and analyses its transmission characteristics from mechanical,electronic and internal flow fields respectively.Based on the overall simulation model of the electronically controlled Multi-Slip limited differential,the transmission efficiency of the electronically controlled Multi-Slip limited differential under the electro-hydraulic integrated environment is studied,and the transmission characteristics of the electronically controlled Multi-Slip limited differential under different working conditions are simulated and analyzed.It has been verified by experiments.The details are as follows:From the point of view of mechanical and electronic control,the influence of transmission links on the transmission characteristics of Multi-Slip limited differential is considered.Based on the structure and working principle of the electronically controlled multi-slice clutch limited slip differential,the power loss of each mechanical transmission link of the electronically controlled multi-slice clutch limited slip differential is deduced and analyzed,and the power loss mathematical models of clutch friction,gear engagement,bearing friction and oil seal in transmission components are established.The transmission characteristics of the motor are analyzed.There is a close relationship between the parameters of the motor,such as the transmission torque and the current.The influence of lubricating oil on the transmission characteristics of electronically controlled Multi-Slip limited differential is considered from the fluid point of view.Based on XFlow flow field analysis software,numerical simulation of the internal flow field of the electronically controlled Multi-Slip limited differential was carried out.Through the numerical analysis of the detection points to quantify the changing trend of the flow field characteristics,the simulation results under different working conditions were compared and analyzed.The results showed that in three working conditions,the internal flow field characteristics of the electronically controlled Multi-Slip limited differential were 0.1M in lubricating oil depth and 786 in gear speed.When deg/s,the flow field is ideal,and the lubrication effect of the internal flow field is better,which is conducive to reducing the energy loss.It is proved that the internal fluid characteristics of the electronically controlled multi-slice clutch limited slip differential have a direct impact on its overall transmission characteristics,which provides a basis for the follow-up study of the transmission characteristics of the electronically controlled multi-slice clutch limited slip differential under the electro-hydraulic integrated environment.Considering the electro-hydraulic integrated control environment of the electronically controlled Multi-Slip limited differential,the transmission links and the total power loss model are built based on the theoretical analysis and the MATLAB/Simulink platform.Based on the power loss model,the power loss and transmission efficiency of the electronically controlled Multi-Slip limited differential are simulated under three different conditions:straight line driving,turning driving and extreme condition(one-sided wheel skidding).The results show that the total power loss and transmission efficiency of the differential increase with the increase of input torque of the electronically controlled Multi-Slip limited differential,and the power loss of each component of the differential varies under different working conditions,and the power loss of the clutch has a greater impact on the overall power loss of the differential.The transmission efficiency test-bed of Multi-Slip clutch limited differential is designed and constructed.The mechanical system,measurement and control system of the test-bed are described.Based on the test-bed of the electronic controlled Multi-Slip limited differential,the transmission efficiency test of the differential is carried out.By comparing and analyzing the total efficiency of the differential with the simulation data,the correctness of the transmission efficiency loss theory and simulation model of the electronic controlled Multi-Slip limited differential is verified. |
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