Dynamic Performance Optimization of Ball Joints with Cross Groove for Automotive Driveshaft System 2024-01-2438

The ball joint with cross groove offers both angular and plunging motion. When transmitting the same torque, the cross groove ball joint is lighter than other plunging Constant Velocity Joints (CVJs). It is crucial for the design of the joint and enhancing the contact fatigue life of the raceway to accurately estimate component loads of the ball joints with cross groove. In this study, the transmission efficiency of the joint and the peak value of contact force between ball and the track are used as evaluation indexes for characterizing dynamic performance of the joint. A multibody dynamic model of the joint is established to calculate its dynamic performance. In the model, the contact properties and friction characteristics of the internal structures were modeled, and a nonlinear equivalent spring and damping model was adopted for estimating the contact force. The transmission efficiency loss of the cross groove joint was measured and compared with the calculated values. Taking friction coefficient, pitch radius, ball diameter, pressure angle, raceway inclination angle, and similarity as design variables, the dominate influencing factors on the dynamic performance of the joint were analyzed. A proxy model for estimating transmission efficiency loss and contact force peak of the joint was established based on the established multibody dynamics model of the joint. Using the presented proxy model and the NSGA2 genetic algorithm, and take the five structural parameters of the CVJ as the optimization design variables, and the transmission efficiency and contact force peak of the joint as the optimization objectives, and the optimal solutions of the parameters were obtained.