Research On Torque Characteristics Of Hydro-viscous Flexible Transmission Based On Thermo-elastic Coupling

Hydro-viscous transmission technology uses the shear action of viscous fluid to transfer power.It can flexibly adjust the power of fans,water pumps,shield machines and controllable retarders,which can effectively slow down the impact during startup,improve the operating efficiency of equipment and extend the service life.In this paper,the friction pair system composed of the friction pair and the oil film in the gap is taken as the research object,and the hydro-viscous transmission process is studied.The main contents are as follows:The finite element model of thermoelastic deformation of friction pair in the process of hydro-viscous transmission was established,and the boundary conditions such as convection heat transfer and heat flux were determined.The distribution law of multiple physical fields of friction pair was obtained by finite element analysis.According to the analysis results,under different radial displacement constraints,the disc warping deformation of the friction pair can be divided into two types: the inner end face of the friction pair deforms in the positive direction along the z axis,and the outer end face deforms in the negative direction along the z axis.The inner end face of the friction pair is deformed in the negative direction of the z axis,while the outer end face is deformed in the positive direction of the z axis.Based on the theory of fluid lubrication and the fractal theory of rough surface,the dynamic modeling of the hydro-viscous transmission process was carried out based on the principle of bearing capacity and torque balance.The changes of oil film thickness,angular velocity and output torque of the passive plate were obtained by numerical calculation,and the influence of radial displacement constraints on the torque characteristics of the hydro-viscous transmission was analyzed.Based on the finite difference method,the dynamics models of friction pairs under different radial displacement constraints were established,and the dynamics output was obtained through the joint numerical calculation of Ansys and Matlab.The results show that,compared with parallel friction pairs,when the inner and outer surfaces of the dual plate are constrained by radial displacement,the peak output torque of the friction pair system is increased to a certain extent,but the peak output torque of other radial displacement constraints are reduced to different degrees.The radial displacement constraint shortens the time for output torque to reach its peak.An experimental device for hydro-viscous transmission was built to study the surface temperature changes of the output torque of friction pairs under different deformation forms.The results show that the overall change trend of the experimental results is the same as that of the theoretical results,which verifies the rationality and reliability of the theoretical model.