Jtekt Corporation

Satoshi Fujita

Tetsuya Kaneko

Toshihiro Asakura

Masashi Yamaguchi

Masayoshi Asakura

Shuhei Yamashita

Ryuji Shibata

A rack housing and a reduction drive housing accommodate a ball screw mechanism and a reduction drive. Within the rack housing and the reduction drive housing, a gap is provided between the left end of a nut and the rack housing, and a gap is provided between the right end of the nut and the rack housing. A groove serving as a communication path in communication with the gaps on both axial sides of the nut is provided in the outer circumferential surface of the nut. The groove is provided so as to avoid a recirculation path provided in the nut. The groove is provided axially and rectilinearly from the end of the nut that is located on the side opposite to a flange, to the flange and is provided along the flange.

Steering apparatus

Provided is a ball screw device in which a deflector can securely be prevented from falling into a nut when the deflector is attached. A ball screw device includes a ball screw shaft, a nut, rolling elements, a ball recirculation path, and a deflector. An attachment hole has a pair of first faces. The deflector has a pair of second faces that respectively face the pair of first faces in a state in which the deflector is housed in the attachment hole. The first faces of the attachment hole and the second faces of the deflector have a locking structure in which the first faces and the second faces respectively lock each other in an improper state in which a part of the deflector is inserted into the attachment hole in a posture different from a posture of the deflector housed in the attachment hole.

Ball screw device and steering system including ball screw device

A ball screw device is provided for which quality can be easily evaluated. The ball screw device includes a threaded shaft with a groove formed on an outer peripheral surface of the shaft, and a cylindrical nut whose screw-thread mates with the groove on the threaded shaft via a plurality of balls. The nut has a pair of mounting holes in each of which a deflector is installed and a communication groove that allows the mounting holes to communicate with each other and is open on the outer peripheral surface of the nut and through which the balls can roll. The width W of an opening of the communication groove is smaller than the diameter of the ball.

Ball screw device, power transfer mechanism, electric power steering apparatus, and method for manufacturing ball screw device

In an electric power steering system, there is provided a ball screw deflector configured to make it possible to easily measure the whole length of each of deflector pieces. A mating face of each of the deflector pieces and end faces of the deflector pieces are parallel to each other, and have an angle corresponding to a lead angle of a ball screw portion. Thus, it is possible to reduce the amount of material required to form each of the deflector piece pieces. In addition, it is possible to easily measure the overall length of each of the deflector pieces with the use of measuring equipment such as a vernier caliper.

Growing community of inventors

Okazaki, Japan

Satoshi Fujita