Jtekt Corporation

Koyo Machine Industries Company Limited

Naoto Miyawaki

Kenji Higashi

Masanori Kobayashi

Shoji Sasaki

Yoshinobu Ogura

Seijun Inoue

A spline telescoping shaft includes an inner shaft including a male spline and a tubular outer shaft including a female spline. A resin film is provided on a surface of at least either of both the splines. An addendum modification coefficient e, the number of teeth Z, a module m, a reference pitch circle diameter PCD, a tip circle diameter dand a root circle diameter dof the male spline and a tip circle diameter Dand a root circle diameter Dof the female spline have relations expressed by expressions (1) to (8).(+4)&#x3e;(+2)&#x2003;&#x2003;(1),(&#x2212;1)&#x2003;&#x2003;(2),(+4)&#x3e;(+2)&#x2003;&#x2003;(3),(&#x2212;1)&#x2003;&#x2003;(4),&#x2003;&#x2003;(5),&#x2003;&#x2003;(6),&#x2003;&#x2003;(7),and0.4&#x3c;&#x3c;1.1&#x2003;&#x2003;(8)

Steering spline telescoping shaft, and steering device

A telescopic shaft includes a hollow outer shaft, an inner shaft spline-fitted to the outer shaft, a resin coating provided on splines on at least one of the outer and inner shafts, and can be extended and contracted in an axial direction. A method for manufacturing the telescopic shaft includes press-fitting the inner shaft into the outer shaft and sliding one of the outer and inner shafts relative to the other of the outer and inner shafts by reciprocating the one shaft in the axial direction. In the sliding, a frequency according to a sliding speed at which the one shaft is slid relative to the other shaft is set to be lower than a predetermined value at the start of sliding, and the frequency is increased in a continuous or stepwise manner when a sliding load of the one shaft to the other shaft is reduced.

Method for manufacturing telescopic shaft

A method of manufacturing a spline telescopic shaft, includes a sliding step of sliding in an axial direction an inner shaft manufacturing intermediate member and an outer shaft manufacturing intermediate member, in one of which a resin coating is disposed on splines. In the sliding step, a sliding load of the inner shaft manufacturing intermediate member and the outer shaft manufacturing intermediate member is detected, and sliding is ended at a timing when the detected sliding load reaches a threshold load which is determined based on an initial sliding load detected at a start of the sliding.

Method of manufacturing spline telescopic shaft

A motor vehicle steering shaft () is provided with: an inner shaft () and a tubular outer shaft () fitted into each other and to transmit a torque to and from each other; a rigid coupling element () for rigidly coupling the inner shaft () and the outer shaft () in a circumferential direction (C) of the inner shaft () when a relative rotation amount of the inner shaft () and the outer shaft () exceeds a predetermined range; and an elastic coupling element () for elastically coupling the inner shaft () and the outer shaft () in the circumferential direction (C) of the inner shaft () when the relative rotation amount of the inner shaft () and the outer shaft () is within the predetermined range. The elastic coupling element () includes a resin member (). The inner shaft () and the outer shaft () are elastically supported mutually via the resin member () at a central position of the predetermined range when no torque is loaded to the steering shaft ().

Growing community of inventors

Yamatokoriyama, Japan

Naoto Miyawaki