Abstract: A hypocycloid gear assembly for converting pure linear motion to rotational motion having a pinion shaft, a pinion carrier, and a ring gear. The pinion shaft has a pinion journal which moves in a purely linear direction. A pinion body is connected to the pinion journal and is offset therefrom. The pinion body is placed inside a carrier body of the pinion carrier. The pinion body rotates around the center of axis of the carrier body, causing the carrier body to rotate on its own axis. An output shaft, whose centerline coincides with the centerline of the carrier body, rotates on its own axis and has a purely rotational motion.