Patent ID: 6425455
Filing Date: 2002-07-30
Classification: B62D,F16H,Y10T

Abstract:
An electric power steering apparatus, comprising:a motor for steering assistance; a worm to which an output of said motor is transmitted; a worm wheel including an annular tooth portion made of synthetic resin and a boss portion made of metal, said annular tooth portion having teeth that engage with said worm, said boss portion being fitted to an inside peripheral surface of said annular tooth portion; a steering shaft to which the output of said motor is transmitted via said worm and said worm wheel; concaves disposed on both axial ends of an outside peripheral surface of said boss portion; and convexes disposed on both axial ends of the inside peripheral surface of said annular tooth portion, said convexes being fitted into said concaves, wherein a radial length of said concaves and said convexes is 1 to 2.5 times as large as an axial length of said concaves and said convexes.