WORM SPEED REDUCER AND ELECTRIC POWER STEERING DEVICE

摘要

An elastic force in the direction toward a worm wheel is applied by a helical coil spring (30) to a worm shaft (29) through a preload pad (70). The preload pad (70) restricts a displacement in the width direction by part of a side face of a holder (61) fixed to a gear housing (22). A side face of the preload pad (70) is made to be in contact with the part of the side face of the holder (61) by elastic deformation of the preload pad (70) itself caused by the elastic force of the helical coil spring (30). This reduces a gap between the preload pad (70) and the part of the side face, and as a result, tooth hammering noise production in a worm speed reducer (16) is suppressed.