Research On New Electrical Drive System With The Function Of Anti-slip And Differential Based On The Viscous Couplings

In recent years, energy shortage and environmental degradation has become the focus of attention. It is the general trend to develop the electric vehicles to reduce emissions. Electric vehicle has two drive forms: centralized driving and independent driving. Compared to the centralized driving, independent driving electric vehicles can improve the trafficability by controlling each drive wheel independently. But, when the vehicle is on the bad situation, the control strategy applied to the independent driving will cause the drop of vehicle dynamics and influence the acceleration. In order to solve this problem, this paper will match a power coupling device for two-motor driven vehicle, and do research on its working principle and the vehicle dynamics by electromechanical coupling control. This paper is supported by Natural Science Foundation of China.Firstly, analyzed the structure and operation principle of the viscous coupling, established the torque transmission models of the three work phases of viscous couplings, including initial phase, shear stage and hump stage. Obtained the accurate expression of shear stress by derivation and solve, analyzed and calculated the process of viscous couplings’ internal temperature. so the model is modified. Then study the causes and course of the hump phenomenon happend and analized the temperature and pressure at the time, provide theoretical support to the structure design and the parameter matching of viscous couplings.Secondly, a simplified geometric model of the internal flow field of viscous coupling is established by the Gambit. Obtained the high quality meshes after meshing, then the viscous coupling’s internal flow field is calculated by numerical method by the Computational Fluid Dynamics analysis software Fluent. The simulation results report the distribution of velocity, pressure, temperature and any other parameters. So the state of the internal flow field is obtained and terrified the working principle of viscous couplings.Thirdly, optimized the internal structure of viscous couplings, validated the positive impact on the output torque of viscous couplings with the optimized parameters. Consider practical design requirements, combined with relevant theory and experience, designed and manufactured a test piece of viscous couplings. According to the testing system, test bench is established. The results proved that the viscous couplings match the requirement. On this basis, I tested the torque transfer characteristic of the viscous couplings with difference arameters. The results proved that the theoretical model has a good accuracy from comparing with the result of theoretical calculations.Finally, using the vehicle model built by predecessors, the simulation of vehicle with Electromechanical coupling anti-slip control has been done. The purpose for that is to test vehicle power performance on bisectional roads and handling stability under turning conditions. From the results we can found that the independently driving vehicle power performance has been improved greatly under electromechanical coupling anti-slip control.