The inner C.V.Joint is a part connecting the differential and the shaft, which has the functions of transmitting torque, changing the working angle, compensating the axial slip and so on. The inner C.V.Joint structure mainly includes TJ structure, VL structure, AAR structure, DOJ structure, LJ structure, ETJ structure, EDJ structure and PTJ structure, among which the most commonly used are TJ structure, VL structure, AAR structure, DOJ structure and LJ structure. The outer housing of TJ structure, AAR structure, DOJ structure are using precision forging and forming technology to ensure stable raceway size, excellent surface accuracy,and to achieve high NVH performance.