Research On Design Theory Of V-Belt CVT

Some basic researches are introduced in the paper of《Research on Design Theory of V-Belt CVT》, which is based on design theory of belt transmission. Some disruptive results is also concluded in this paper. The main contents of this paper is summarized as fellow:(1) Four basic laws that theory of belt drive should conform to are presented. The basic laws, including elastic law, seriation of length law, flow conservation law and moment balance law, lay a strong foundation for the study of belt transmission theory.(2) Several problems about the formulas for equivalent coefficient of friction in V-belts transmission are studied and some revision on the formulas which are presented in existing teaching material and references are also proposed.(3) Three parameters including belt initial tension F0 , effective belt tension Fe and dynamic arc angleαare important factors for the design theory of belt transmission. Dynamic arc angle surface equation is derived by the three parameters,and the surface properties of dynamic arc angle surface is studied.(4) A thorough research concerning the influence of the centrifugal force on the fixed belt transmission and V-belts'continuously variable transmission. For a fixed belt-type transmission, increased centrifugal force can enlarge the dynamic arc angle, and ultimate bearing capacity of the belt-type transmission decrease. But increased centrifugal force does not affect ultimate bearing capacity for V-belts'continuously variable transmission.(5) A calculation formula of belt's axial offset, as well as an adjustment method of axial offset are presented, and formulas of the installation position of belt wheel are concluded.(6) Based on the flow conservation law, velocity difference between the tighten belt and the loose that is caused by the pull difference between them is explained, also the slippage rate and the formulas of efficiency are derived and simplified in this paper. The slippage rate and the formulas of efficiency can be calculated directly according to initial tension and effective pullwithout experiment.