Transmission ratio varying mechanism for steering-system of motor vehicle, has carrier driving device that causes carrier to rotate such that mechanism varies transmission ratio of rotation between steering shafts

摘要

The mechanism has an eccentric rotary plate (3) whose two cycloidal grooves (302, 303) are formed concentrically at an axial center of the eccentric rotary plate. Cycloidal grooves (103, 203) of steering shafts (1, 2) are formed concentrically at an axial center of the shafts, where transmission of rotation of the eccentric rotary plate and one of steering shafts (2) are implemented via a rotation transmitting ball group (7). A carrier driving device (20) causes the carrier to rotate such that the transmission ratio varying mechanism varies transmission ratio of rotation between the shafts.