Design And Study On The Torque Behaviors Of Liquid Viscous Couplings

Developed with liquid viscous transmission technology, liquid viscous couplings (LVC) are increasingly applied to four-wheel-drive cars. Whereas, the research on torque characteristics, working fluid, two-phase flow in LVC hasn't been mature by now. Further study is undertaken based on former researches in this paper.This paper consists of five chapters. The first one mainly explains the background and significance of study, the principle of liquid viscous transmission technology and the application of LVC. The concept and type of full-time four-wheel-drive cars were introduced. The second one presents achievements on LVC including the torque calculation models while the silicone oil was Newtonian flow and Non-Newtonian flow respectively. The mechanism of hump phenomenon and the time of Self-Induced Torque Amplification and the required minimum rotational difference speed were also concluded. The third one describes the properties of working fluid and some experiments on viscous-temperature curves of silicone oil, named as 0.017m2/s, 0.027m2/s and 0.037m2/s. The experimental results demonstrate that the dimension of plate and properties of working fluid have influences on life-span and torque transfer performance of LVC. In chapter four, the strength of each component of LVC were designed and corrected and the new seals were used and the space between the inner and outer plate is 0.4mm. The fifth chapter describes the structure of LVC and the experimental system. A series of experiments were conducted with different viscosities, original filling rate and rotational speed. And the inner temperature of LVC is also measured and the correlations under different rotational speeds, viscosity and original filling rate are given. Calculation results have been compared with the experiment datas and analyzed in detail. Some useful conclusions are obtained in the last chapter.In a word, the designed LVC can work well under the viscous shear and hump working modes. The torque transmission experiments meet with the anticipated goal. The emphases in this paper are the seal and the highest temperature prediction ofLVC. The calculating method and conclusion are very useful to further research on torque transfer characteristics.