Contact Analysis Of Ball-Cage Type Constant Velocity Joint In Multibody System

Contact-impact phenomenon is widespread in multibody system. Multibody system dynamics problem containing contact-impact is currently a hotspot and difficulty. Being a typical example of multibody system for contact-impact, Ball-basket constant velocity universal joint relies on conjugate contacts between ball with internal and external tracks to complete the constant velocity transmission between two non-collinear shafts. Based on the multibody system dynamics, multibody dynamics analysis software such as ADAMS and DADS has been widely used. The application of visualization software provides a convenient and effective way to solve these problems.This thesis investigates the contact-impact problems of multibody system. Ball basket constant velocity universal joint is taken as a sample application and ADAMS software is implemented to analysis the contact dynamic simulation models.Firstly, the paper reviews development situation and application of multibody system dynamics from such aspects as modeling approach、 numerical algorithm and characteristic analytical method. The research situation of contact-impact problem and the application status of universal joint in automobile universal transmission system are overviewed.Next, the rigid body’s center-of-mass coordinate and body-fixed coordinate system’s Euler angle are chose as the generalized coordinates. Applying Lagrange method, the dynamical equation of multibody systems has been derived. Based on the multibody system dynamics and rigid body contact theory, the movement equation of multibody systems containing contact impact has been derived. Combining different methods building contact-impact models, the dynamical equation of multibody systems during the process of contact-impact has been derived. The detection of contact bodies is based on bounding box levels tree intersect detection algorithm. ADAMS software implements the above theoretical basis to settle the contact problem of multibody system.Further, the parts geometric structure of ball basket constant velocity universal joint is researched, which provides the basis for the geometric model established by applying Pro/E. The calculative method of parameter identifying contact between parts is analyzed. It is also the difficult problem when utilizing ADAMS software to establish the universal joint contact simulation model.Finally, the simulation model of BJ75type of ball basket constant velocity universal joint is established. The simulation results are analyzed from the following aspects, such as the constant velocity transfer, absolute and relative motion of ball center, curve of contact point’s position, contact force in the contact point and so forth. These results provide the basis for fatigue calculations of ball basket constant velocity universal joint.