Patent ID: 9469335
Filing Date: 2016-10-18
CPC Classification: B60G,B62D

Claim Text:
1. A rear wheel steering apparatus for a vehicle, the rear wheel steering apparatus configured to be mounted on a suspension mechanism that supports rear wheels of the vehicle and steering the rear wheels, the rear wheel steering apparatus comprising: a housing configured to be connected via a first connection member and a second connection member to the suspension mechanism; an electric motor accommodated within the housing; a planetary gear mechanism including a sun gear connected to an output shaft of the electric motor, a ring gear supported within the housing to be non-rotatable, a planetary gear meshing with the ring gear and the sun gear, and a carrier connected to the planetary gear, the planetary gear mechanism decelerating an output of the electric motor; a linear motion mechanism including a nut member connected to the planetary gear mechanism and constituting the carrier, and a rod threadedly engaged with the nut member and connected to the second connection member, the linear motion mechanism converting a rotary motion of the nut member to a linear motion of the rod, the housing including a cylindrical body which accommodates the electric motor and the planetary gear mechanism in a state where the electric motor and the planetary gear mechanism are arranged in tandem with each other and which includes a lock portion provided at an inner surface of the cylindrical body to be positioned between the electric motor and the planetary gear mechanism, the housing including a connection cover including the first connection member and closing an opening portion of the cylindrical body; a cylindrical holding member holding the ring gear within the cylindrical body in a state where the ring gear constituting the planetary gear mechanism is prevented from rotating; a bearing supporting the nut member in a manner that the nut member is rotatable relative to the cylindrical holding member; wherein the bearing and the cylindrical holding member are disposed and held between the lock portion of the cylindrical body and the connection cover; the cylindrical holding member is held to be non-rotatable relative to the cylindrical body; the ring gear includes an engagement portion protruding outwardly in a radial direction of the ring gear; and the cylindrical holding member includes a locking portion locking the engagement portion in a circumferential direction of the cylindrical holding member.