STEERING DEVICE FOR VEHICLE

摘要

A steering device (1) for a vehicle comprises a transmission ratio variable mechanism (5) which can alter the transmission ratio (?2/?1), and a mechanism (19) for imparting auxiliary steering force. The transmission ratio variable mechanism (5) comprises an input member (20) and an output member (22) rotatable about a first axis (A), an inner ring (391) for coupling the members (20, 22) to enable them to perform differential rotation, an outer ring (392) for supporting the inner ring (391) rotatably through a rolling element (393), and an electric motor (23) for the transmission ratio variable mechanism for rotary driving the outer ring (392). The central axis, i.e. the second axis (B), of the inner ring (391) and the outer ring (392) is inclining against the first axis (A). The motor (23) holds the outer ring (392) to enable it to rotate together and has a rotor (231) rotatable about the first axis (A), and the rotor (231) has a tubular shape surrounding the outer ring (392).