Study And Optimization Of Hydro-viscous Flexible Transmission And Thermal Deformation Of Friction Pair

As a new type of fluid transmission technology,hydro-viscous transmission transits power through the shear action of viscous fluid.It is mainly used in the flexible power regulation field of medium and high-end mechanical equipment such as wind power generation,shield machine and controllable reducer.The fluid viscous flexible transmission can effectively reduce the impact in the starting process,improve the transmission accuracy and prolong the service life of the parts.Therefore,this paper comprehensively adopts theoretical modeling,numerical calculation and experimental verification methods to study the flexible transmission process of HVD.The main contents are as follows:Firstly,the micro-friction mechanism of the hydro-viscous flexible transmission process is deeply analyzed.Based on the theory of fluid lubrication theory and rough surface fractal theory,the dynamic modeling of the flexible transmission process is carried out through the principle of bearing capacity and torque balance.By numerical solution,the variation of oil film thickness,driven plate angular velocity,output torque and viscous torque with time is obtained.Finally,the influence of different parameters,including engagement pressure,lubricating oil viscosity and fractal dimension,on the dynamic characteristics of flexible transmission is analyzed by this model as well.In order to maximize the transmission efficiency and maximize the time proportion of fluid and mixed lubrication,an optimization model for the transmission process of HVD is established.The optimization result is obtained by using NSGAII.After optimization,the efficiency and stability of the transmission process are improved.Based on the optimal design result,the mechanism of heat generation,transmission and distribution of friction pair is analyzed.The finite element model of friction pair is constructed according to the finite element theory.Through the finite element analysis,the distribution of temperature,stress and displacement can be obtained.It can be seen that the optimized friction pair can effectively avoid the permanent damage caused by excessive temperature or stress and improve the service life of the friction pair.The experiment system of the HVD is set up to carry out experiments.The relationship between the output torque and engagement pressure,the ratio of inner and outer radius is studied,as well as the change of the output torque,the surface temperature and displacement of the friction pair before and after the optimized design.The results show that the overall variation trend of experiment results is the same as that of theoretical results,which verifies the rationality of the theoretical model and the reliability of the optimal design.Figure 63 table 17 reference 76...