Study On The Influences Of Thermal Effect Of Oil Film On The Torque And Thermoelastic Stability Of Hydroviscous Drive

Hydro-viscous transmission technology uses the shear action of viscous fluid to transmit power,which is a new type of fluid transmission technology.In this paper,the method of theoretical modeling,numerical calculation and experimental research is used to analyze its transmission performance and thermal elastic stability,mainly including the following aspects:Firstly,the two-dimensional model of the friction pair is established and meshed,and the transient analysis of the oil film is carried out by using the fluent simulation software,considering the changes of oil film pressure,temperature,flow rate and torque of the liquid viscous speed control clutch under five working conditions,and the parameters before and after the deformation of the friction pair are analyzed,and the results show that the friction pair can increase the torque of the oil film.The influence of inlet pressure,temperature gradient,soft start time,heat flux density,friction pair thermal deformation and other working conditions on the flow field and transmission performance of friction pair oil film was obtained.Secondly,through the perturbation model,the two-dimensional thermoelastic stability model of the friction pair is established,and the stable state of the friction pair of the HVD is analyzed in the fluid friction stage,the mixing friction stage,and the boundary friction stage after deformation,and the perturbation growth coefficient and the critical speed are obtained through the computational solving,and the following conclusions are made: the transmitting torque is improved and the stability of the system is reduced in the case of deformation of the friction pair,the real cause of hot spot produced by the friction pair is obtained,and the influence law on the transmission performance and the temperature field of the flow field is obtained.The change law of thermoelastic stability of the friction pair after deformation was analyzed.The results show that after the deformation of the friction pair,the transmission torque is increased,the system stability decreases,and the system stability decreases to a certain extent.Finally,the experimental system of HVD is set up to carry out bench experiments to study the distribution of inlet pressure,Temperature gradient,soft start time,heat flux density,friction pair heat deformation and output torque,and the influence law of oil film temperature,pressure and flow rate.The results show that when the experimental results are compared with fluent simulation,the two patterns of change are consistent,which verifies the correctness of the simulation.By measuring the temperature of the friction pair surface,the influence of deformation on the critical speed of the friction pair is indirectly obtained.