Patent ID: 7275618

Claim:
An electrically driven power steering apparatus comprising: a motor; a moving shaft to which an assistive steering force is inputted from the motor, and which is reciprocally movable within a range restricted by a housing in order to steer wheels; an input shaft connected to a steering wheel; a power transmission mechanism which connects the input shaft with the moving shaft in a power transmissible manner; and an absorbing member which is attached to one of the moving shaft and the housing, and is brought into contact with an abutment portion disposed on the other of the moving shaft and the housing to absorb an impact at an end of the reciprocal movement of the moving shaft; wherein the absorbing member comprises a material selected to satisfy the following relationships: 200≦σ/ε≦666(Mpa) 0.2≦ε≦0.3 σ/ε= F /( S ·ε) 30,000 ≦F ≦40,000( N ) 3×10 −4 ≦S ≦5×10 −4 (m 2 ), where σ is compressive stress, ε is strain, F is compressive load (N), and S is compressed area (m 2 ).