Thk Co., Ltd.

Yuji Tachikake

Takeki Shirai

Soshi Miyahara

Masahiko Yoshino

Takashi Sakuyama

Akihiro Teramachi

Tsutomu Togashi

Toshiro Minami

Toshihisa Sakamoto

Lina Teng

Katsuhito Imai

Shinji Izumi

Kazuhiko Akiyama

This rotation-linear motion conversion apparatus () includes: a pinion shaft () in which a pinion gear () is formed; a rack bar () in which a rack gear () that engages with the pinion gear () and a support surface () along a longitudinal direction are formed; and a support part () that supports the rack bar () movably along the support surface (). The support part () prevents a movement of the rack bar () in a direction X perpendicular to a surface () in which the rack gear () is formed.

Rotation-linear motion conversion apparatus and steering apparatus

A screw device manufacturing method ensures high productivity and adequate nut strength. The disclosed screw shaft manufacturing method includes: a groove forming step of forming a loaded ball rolling groove in a flat plate; and a nut forming step of bending the flat plate into a ring to form a nut. As the groove forming step of forming of the loaded ball rolling in the flat plate is followed by the nut forming step of bending the flat plate into a ring, sufficient strength of the nut can be easily achieved. Besides, a high compression stress is left in the loaded ball rolling groove in the inner surface of the nut.

Screw device manufacturing method and screw device

A ball screw device having a novel ball circulation structure suitable for a screw shaft with a large lead, optimum for downsizing and weight saving of a nut member, capable of being manufactured at low cost, and capable of exhibiting high reliability even under severe use conditions. In a ball screw device where a screw shaft and a nut member are screwed to each other through an intermediation of a large number of balls, a no-load ball path which forms an infinite circulation path for the balls is constituted by a no-load ball groove spirally formed in an inner peripheral surface of a through-hole of the nut member and by a pair of direction change grooves which communicatively couple a load rolling groove and the no-load ball groove to each other so as to complete the infinite circulation path as a closed loop.

Ball screw device

A rolling guiding device makes it possible to easily provide a movement block with an endless circulation path for the balls. In one surface of a movement block opposed to a rolling groove of a raceway rail, there is formed a track groove through which balls makes an endless circulation. The track groove is includes a load straight-line groove which allows, between the track groove and the rolling groove of the raceway rail, the balls to roll while bearing a load. It also includes a pair of ball deflection grooves respectively provided at both ends of the load straight-line groove and adapted to release the balls having rolled through the straight-line groove from the load and to change their rolling direction, and a non-load straight-line groove for transferring the ball in a non-load state from one deflection groove to the other ball deflection groove.

Rolling guiding device

Growing community of inventors

Tokyo, Japan

Yuji Tachikake