| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive shaft for use in an electric reclining mechanism of a seat, which reduces weight.SOLUTION: A drive shaft 20 of the present invention is a long shaft body capable of transferring a driving force. A protruding streak part 22 and a recessed streak part 21 are alternately formed along a circumferential direction on an outer peripheral surface of the shaft body. A hollow part 23 is formed along an axial direction almost in the center of the cross section of the shaft body. The hollow part 23 is formed in such a shape as to open to the outside at one end and the other end of the shaft body. |
