Electric power steering apparatus

摘要

An electric power steering apparatus is provided with a worm (6) which is a driving gear interlocked with an electric motor for assisting steering, and a worm wheel (7) which is a driven gear having an annular teeth body (71) made of synthetic resin meshing with the worm (6) and a metallic core body (72) coupling the annular teeth body (71) and is attached to the steering shaft (3).
Protrusions (73) are provided on a side surface of the annular teeth body (71) in a face width direction at a plurality of circumferential positions from which a distance to a center of rotation is different from each other, and stirred lubricating fats and oils applied around the worm wheel (7). As a result, the lubricating fats and oils can be moved to between tooth surfaces of a meshing portion between the worm (6) and worm wheel (7). To provide the electric power steering apparatus capable of increasing a circulating quantity of lubricating fats and oils circulating with rotation of the driving gear (6) and the driven gear (7).