Design Of Teeth-adjustable CVT And Study On It’s Strength

Among four types vehicle automatic transmissions, including AT(Hydraulic Automatic Transmission), AMT(Automated Mechanical Transmission), DCT(Dual Clutch Transmission), and CVT(Continuously Variable Transmission),only CVT is the real continuously variable transmission. CVT can make the vehicle engine run in economic speed and raise vechile’s fuel economy & lower exhaust emission. So CVT is ideal automatic transmissions for vehicle. But traditional CVT uses friction driving as power transmission way, that limit the capacity of load transmission and transmission efficiency.Because the teeth-adjustable CVT changes friction transmission of traditional CVT into mesing transmission, its the capacity of load transmission and transmission efficiency improve greatly.The advantages of teeth-adjustable CVT make it to be a industrialization a new product that has a broad prospect. Nowadays, teeth-adjustable CVT is in a rinciple prototype phase and there are still several problems to be solved. On the base of the exploiting of rinciple prototype by national manufacturers, the teeth-adjustable CVT’s continuously variable transmission mechanism is designed and its strength is studied in this thesis and it have great theoretical significance and high practical value in accelerating teeth-adjustable CVT’s industrialization and changing the situation that our country’s high-end automatic transmissions long term dependence on imports. The main research work and innovation points of this thesis including:(1) On the base of systematical analysis teeth-adjustable CVT’s transmission principle and according to the characteristic that CVT’s continuously variable transmission is less prone to contrarotate, a new transmission scheme that transmisson’s reverse can realize without contrarotating of continuously variable transmission.(2) Key components and parts of teeth-adjustable CVT, including adjustable teeth unit, metal cone disc, and tooth shape mental chain are designed in detail. Three-dimensional model of continuously variable transmission system is built and the model’s assembly simulation is made,using Solid Works. The matching between adjustable teeth unit and tooth shape mental chain is anasyzed, using kinematic method and continuously variable transmission is designed.(3) The meshing movement between adjustable teeth unit and tooth shape mental chain is anasyzed, using kinematic method. The transmission scheme that four adjustable teeth units are arranged between the removable metal cone disc and fixed metal cone disc is proposed and the maximum of meshing silps are confirmed. The maximum stress of adjustable teeth slip and mental chain are calculated.(4) The statics characteristics of cone disc and adjustable teeth unite which are the key parts of teeth-adjustable CVT are studied using static analysis module of ANSYS Workbench. The maximum comprehensive stress,the maximum strain value, and the maximum deformation of cone disc and adjustable teeth unite are obtained and it’s distribution are given.