Patent ID: 9322456
Filing Date: 2016-04-26
CPC Classification: B62D,F16G,F16H

Claim Text:
1. An electric power steering device comprising: a steered shaft that changes a steering angle of steered wheels responding to steering operation; a motor that applies assist force to the steered shaft; a drive pulley that includes helical teeth and is connected to an output shaft of the motor; a driven pulley that includes helical teeth and is arranged coaxially with the steered shaft; and a belt that includes helical teeth meshing with the helical teeth of a set of the drive pulley and the driven pulley, and is wound around the set of the pulleys, wherein: the helical teeth of at least one of the pulleys and the belt each have a first end, an opposite second end having a thickness smaller than that of the first end, and a center region therebetween in the width direction of the at least one of the pulleys and the belt, and the helical teeth of the at least one of the pulleys and the belt each have a tooth thickness that is reduced from the center region toward the first end and from the center region toward the second end.