Planetary transmission and assembly method

A planetary transmission comprises coaxial driving and driven shafts and a cam mounted first member straddled by second and third members on the common shaft axis, roller bearings on the first working with races on the other two members of the transmission. The balls (11) or rollers (11) should be in apertures (12) on the mounting circumference (18) of the first member designed as a disc (6) enclosed by a tight fitting tyre (23), the disc areas contacting the balls etc. made from carbon steel, aluminium or plastics. The aperture size is twice the ball etc. amplitude and twice the sine amplitude of the attendant races. In assembly, the second member with the race is fixed to the main body, the first disc freely mounted on the shaft cam, balls inserted and finally engaged by the third member race on the far side. First an alloy steel ring (21) should be pressed into the disc endface, then the disc laid flat to insert the balls, with interposed webs (22), and finally the tyre ring fitted, so completing the disc for mounting on the shaft cam etc.