| Hydro-viscous transmission is a new type of fluid transmission method which is based on Newton's law of viscosity,and it uses the viscosity of the fluid or the shearing action of the oil film to transfer power.It is widely used in the field of speed regulation of large power equipment,such as fan,water pump and belt conveyor.Its application value of energy saving and no pole speed regulation effect is huge.At present,there are a lot of researches on the transmission mechanism of oil film and the influence of oil groove structure parameters on the thermal stress of the friction pair,but there still few studies on the influence of oil groove section shape and oil groove distribution on the transmission performance of hydro-viscous drive.The influence of oil groove morphology on the performance of hydro-viscous transmission was researched in this paper.The main contents are as follows:The oil film bearing capacity model,velocity model and transmission torque model were established under the fluid friction condition,and the heat conduction model,the calculation model of heat flux and convective heat transfer coefficient were also established under the mixed friction condition.Based on the structure characteristics of oil film and friction plate,the numerical calculation model of oil film and friction plate were established.The temperature field,pressure field,velocity field and transmission torque of the fluid between friction pairs were solved by Fluent.The results show that the highest temperature of the oil film of trapezoid oil groove is lower than that of the other oil groove under the same working condition.The transmission torque of triangular oil groove oil film is larger than that of other oil groove section,and the cooling effect of chute and circular groove is slightly better than that of radial groove.The temperature field,stress field and axial displacement of the friction plate with different oil groove morphology were simulated by Ansys.The results show that the temperature of non-grooved region of the friction plate is higher than that of grooved region whether the morphology of oil groove is the same or not,and the obvious heat spots are formed in the non-grooved region.The axial displacement produced by the thermal stress and mechanical stress in the rectangular oil groove is smaller than that of the other section of groove.The cooling effect of the circular groove friction plate and the fluid flow of the oil are better than that of the chute and radial groove,and the axial displacement is relatively smaller.The difference between the displacement of the friction plate due to the thermal stress and the inner spline constraint and the thickness of the friction plate is several orders of magnitude.It shows that the main failure forms of the friction plates are the peeling of the friction lining and the high temperature ablation,not the friction and the warp.According to the experimental requirements,hydro-viscous drive experiment bench was designed and built.The experimental results show that under the same working conditions,the temperature rise of the grooved region of the friction pair is lower than that of the nongrooved region,and the oil film transmission torque increases with the increase of the inlet flow in the same condition.The transmission torque of triangle oil groove is larger than that of other oil groove. |
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