Patent ID: 7455148
Filing Date: 2008-11-25
Classification: B62D,F16C,F16H,H02K,Y10T

Abstract:
1. A worm reduction gear comprising a worm wheel, a worm shaft and an elastic body, wherein the elastic body applies an elastic force to the worm shaft in a direction towards the worm wheel via a pre-load pad, and the worm wheel is fixed freely to an assist shaft, and opposite ends of the worm shaft are supported on the inside of a gear housing by a pair of bearings, and a worm provided in an intermediate portion of the worm shaft meshes with the worm wheel, and the pre-load pad comprises a pair of elements which form a discontinuous portion centrally in a widthwise direction of the pre-load pad, and displacement of the pre-load pad in relation to a predetermined direction, is restricted by a guide face provided on the gear housing or on a member fixed to the gear housing, and the pre-load pad having a substantially non-circular inner peripheral face resulting that a clearance between the pre-load pad and the guide face is either eliminated or reduced by movement of the pair of elements in a direction to separate from each other, based on an elastic force of the elastic body.