Abstract:One of the new kind of planetary tranmission composed of the ring involute spherical gear and its driving mechanism is introduced, and the conformation of the new planetary tranmission, and kinamatic are also analyzed. The new planetary tranmission is composed of two spherical gears and one bracket. The output axle can swing toward all directions. Synthesizing one of the spatial driving mechanisms which is used to control the orientation of the bracket. The movability of the driving mechanism is analysed. The kinamatic model between the orientation angle of the output axle and the control motor has been found, based on which the orientation angle can be controlled accurately.