The function of the transmission mechanism is to transfer the movement mode (rotation or rest) of the A part to the B part through a certain mechanism (or part). For example, the shaft (or sleeve) rotates the transmission seat through a screw (pin or key), and then rotates the moving ring through a part. The static ring is kept static by anti-rotation and capping. Here, there is no relative movement between the shaft sleeve and the transmission seat and the moving ring, the static ring and the pressure cover.