Research On Several Key Problems Of Three-cone Synchronizer’s Design

Three-cone synchronizer, as a trend of the development of inertia type of synchronizer, can increase the durability, the reliability and the shift comfort of synchronizers efficiently by increasing the number of friction surfaces, the capacity of synchronous torque and decreasing heat load. But in the use of three-cone synchronizer there are circumstances where tooth fighting, excessive abrasion and interference happen as a result of unreasonable design of the parameters like locking angle, cone angle and the clearance between parts. In the dynamic simulation of synchronizers, the change process of some key parameters like impulse force, torque and synchronization time cannot be reflected reliably because of the unreasonable simplifications of constraints and input parameters. In view of above, this thesis studied the key problems about the structural parameters design, dynamic simulation and the analysis of the abrasion of the synchronizing ring and put forward the corresponding solutions to these problems.1. The design of the dip angle of the gear sleeve’s positioning groove, the elasticity coefficient of the positioning spring, the locking angle between the gear sleeve, hub and the joint gear ring, the cone angle and surface frictional coefficient of the synchronizing ring and the design of the axial, radius,circumferential clearance in the assembly of synchronizers are the key solutions to solving the problems mentioned above. This thesis put forward the design method of key structures by building the structural model containing related parameters.2. Based on the motion and stress distribution of the parts this thesis studied the function mode and contact force type among the parts like gear hub, gear sleeve, outer cone ring, middle ring, inner cone ring, joint gear ring, slider and the positioning ball. The author proposed the constraint mode of the parts mentioned above, built the virtual prototype of three-cone synchronizer, studied the shift force in the synchronizing process and put forward the control method of shift force.3. On the basis of the theories of fractal touch and adhesive abrasion, this thesis built the run-in abrasion forecasting model of synchronizing ring. Besides, the author studied the effects of load, relative speed, temperature and the surface morphology on the abrasion of the synchronizing ring. Beyond that, the testing program was also designed for the abrasion testing of the synchronizing ring.