A Study On The Torque And Thermal Behaviors In Liquid Viscous Couplings

Developed with liquid viscous transmission technology, liquid viscous couplings (LVC) are increasingly applied to Four-wheel-drive vehicles. However, the research on torque characteristics, working fluid, two-phase flow of LVC hasn't been quite mature at present. Embedded studies are undertaken based on the former researches in this paper.The emphases in this paper are the effects of plate frame, geometry figure, dimension and properties of silicon oil on the shearing torque. This paper consists of five chapters. The first one mainly introduces the background and significance of the work, principle and application of LVC, as well as the concept and type of Four-wheel-drive vehicles. The second one describes the structure of LVC and properties of working fluid. Indicate that the dimension of plate and properties of working fluid are correlation with life-span and torque transfer performance of LVC. In chapter three, shearing models of Newtonian flow and Non-Newtonian flow have been devised separately. Output torque characteristics according to special plate structure have been studied also. Many factors such as plate frame, dimension and space, original filling rate and viscosity of silicon oil, rotating speed differences etc. are considered in torque calculation. Calculation results compared to the experiment data have been analyzed in detail. The fourth part summarizes mechanism of hump phenomenon and presents a new idea. In the end, the physical and mathematical model on working fluid flow and heat transfer of LVC are attempted to establish. It also explains that air distribution among working fluid in the light of viscous-elastic property of silicon oil. Conclusions and advices are given in the last chapter. The appendix lists shearing torque calculation programs compiled with C++.