Patent ID: 8066093

Claim:
A power steering system comprising: a worm wheel linked to a steering shaft; a wormshaft housed in a housing and adapted to mesh with the worm wheel; a bearing adapted to rotatably support one end of the wormshaft; a bearing holder having a substantially cylindrical holding portion formed to enclose and fit onto the bearing for holding the bearing; and a preloading means located in the bearing holder for preloading the bearing in a direction that the wormshaft and the worm wheel are brought into meshed-engagement with each other, wherein a shaft housing portion is defined in the housing for housing the wormshaft inside of the housing; a holder housing portion is provided at one axial end of the shaft housing portion for housing the bearing holder; the holder housing portion has a restriction wall for restricting a movement of the bearing holder at least in an opposite direction, which is opposite to the direction that the wormshaft and the worm wheel are brought into meshed-engagement with each other, and in a direction perpendicular to the opposite direction; an inner peripheral surface of the holder housing portion, defined by the restriction wall, is formed into a substantially circular shape in lateral cross-section, and a central axis of the inner peripheral surface of the holder housing portion and a central axis of an inner peripheral surface of the shaft housing portion are configured to substantially coincide with each other; and the preloading means comprises a preload portion formed integral with the holding portion of the bearing holder to permit elastic deformation of the preload portion, for forcing the bearing in the direction that the wormshaft and the worm wheel are brought into meshed-engagement with each other, by a force of resiliency of the preload portion.