Research On The V-belt Cvt Performance Of The Large Power Snowmobile

The design and experiment technology of the rubber V-Belt CVT are the most fundamental problems for the large power Snowmobile,and the power rage that it transfers is 18～117 kW, which is supposed to be powerful enough to meet the requirements of patrol velocity and fuel economy on general road condition. Meanwhile, the ability of breaking snow or climbing slope and the basic requirement that the engine cannot flameout in any case also need to be considered. Based on these considerations, sleigh car can shift automatically and quickly according to the complex landform when spinning along at full speed.Currently, the rubber V-Belt CVT has been applied widely, however, the fundamental theories and practice is neglected, therefore, it has important theoretical and practical meanings to study the rubber belt-type CVT system.The project is supported by the Chongqing Science and Technology Commission(CSTC,2008AC0604). The content of this paper is mainly based on the design theory of configuration parameter of the rubber V-Belt CVT, which is fundamental research. The main contents are summarized as follow:(1) The CVT system is analyzed and studied mechanically. A large power rubber belt-type CVT, which is used on sleigh car, is introduced. Related mathematical models are established based on the detail description of the structure and working principle.(2) The concept of equivalent radius of driving wheel is put forward. Clutch weight is core part of driving wheel's speed regulation component. The concept of equivalent radius is put forward according to the effects that the mass,the position of barycenter and working curved surface of Clutch weight has on the pressurized model of driving wheel. The mathematical formula of equivalent radius are deduced in order to set up the pressurized model, which makes preparation for the design of working curved surface of Centrifugal block.(3) The pressurized model of the rubber V-Belt CVT is established and studied. Driving wheel's speed regulation component and driven wheel's torque inductor have great influence on the pressurized model. The relation between configuration parameters and pressurized model is discussed by changing the configuration parameters, which lay the theoretical foundation for the establishing of the entire transmission system model and functional parameter matching of CVT. (4) The control method about the powertrain system matching of sleigh car is analyzed, and the performance matching of CVT is done. The mathematical expressions of maximum and minimum velocity ratio that the whole powertrain system requires are defined through the analysis of driving cycle and dynamic performance of sleigh car and the research of external characteristic curve of engine. Finally, the configuration parameters of CVT are optimized by referring to the scheme of prototype.