Research On The Heat Transfer And Drag Characteristics Of Wet Friction Clutch

Wet friction clutch is widely used in ship transportation,heavy truck and other heavy machinery because it has the advantages of stable starting commutation, large transmission torque, low wear and long service life, but in use process often occur thermal failure problems due to overheating lead to the hot cracks, warping of disc, regional burning loss and stripping of surface materials and the power loss and low transmission efficiency caused by drag torque.For its shortcomings, a wet friction clutch is taken as the research object, the influence of the structure forms and size parameters on the characteristics of heat transfer and drag of the friction discs are studied. The main research contents are as follows:Firstly, the fluid domain parametric finite element model of friction discs with spiral radial groove, double circular groove and waffle groove are created, after determining the turbulence model and boundary conditions, the three dimensional flow field numerical simulation analysis are calculated. At the same time, the flow field distribution of the friction discs under different rotating speed is studied, and the influence of the structure size parameters on the flow field of the friction discs is studied.Secondly, the heat flux calculation model of friction discs transient heat is established and the heat flux is distributed in a certain proportion. According to the results of the second chapter velocity field, the convection heat transfer coefficient of the friction discs is solved. A parametric finite element models of three kinds of friction discs are established for the thermal analysis, and the boundary conditions are accurately applied to three-dimensional transient thermal analysis. Then, the influence of the size parameters of the oil groove structure on the heat transfer characteristics of the friction discs is studied.Thirdly, the mathematical model of the drag torque is established, and the influencing factors are analyzed. The fluid domain parametric finite element models are established. The drag torque characteristics of the oil film with three different oil groove forms are studied.Then, the influence of different oil groove structure size parameters on drag torque of the oil film with three different oil groove forms is studied.Finaly, simulation and analysis results based on the characteristic of friction discs, the improvement scheme is put forward, then the oil groove structure on the surface of the friction discs is improved. Then, the simulation and comparison analysis of the improved friction discs and the original structure is carried out, and the calculation software of the related analysis of this paper is developed. The research can provide some reference for the selection of friction discs,structural design and optimization, and has a certain academic significance and engineering value.