Thk Co., Ltd.

Lina Teng

Masahiko Yoshino

Soshi Miyahara

Takashi Sakuyama

Tsutomu Togashi

Takeki Shirai

Akimasa Yoshida

Kentaro Nishimura

Tetsuya Miura

Toshiaki Kadono

Yusuke Todoroki

Yuji Tachikake

Kazuhiro Tani

Provided is a roller screw capable of preventing rollers moving from an unloaded return path to a loaded roller rolling path from coming into collision with a scooping portion. The roller screw has: a screw shafthaving a spiral roller rolling surfaceformed on an outer peripheral surface thereof; a nuthaving a loaded roller rolling surfaceformed in an inner peripheral surface thereof; a circulation memberhaving an unloaded return path connecting one end of the loaded roller rolling surfaceof the nutto an opposite end thereof; and a plurality of rollersarranged in a loaded roller rolling pathand the unloaded return path. In the circulation member, as a scooping portion that juts toward the screw shaftand provided for scooping the rollersmoving in the loaded roller rolling pathup into the unloaded return path, a pair of diagonal corresponding partsis provided which are in contact with diagonal partsof a rectangular side surface of each rollerand a width between which is gradually narrower as they are deeper in the unloaded return path in such a manner that a cross section of the unloaded return path is closer to a rectangle.

Roller screw

There is provided a new rolling body screw device manufactured with cheap cost without degrading quality in comparison with a conventional device even for a device having any large dimension in an end-cap type rolling body screw device. The rolling body screw device includes the direction changing passageseach including: a scoop-up portionscooping a ball rolling in a loaded rolling body passage as a loaded area of the endless track so as to hand over the balls to the direction changing passageas a non-loaded area of the endless track; and a route pathforming a circulation path of the ball scooped by the scoop-up portion. Each of the return pieces is composed, in combination, of a metal partformed of a metal material including the scoop-up portion, and non-metal partsformed of a non-metal material including the route path

Rolling body 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

Growing community of inventors

Tokyo, Japan

Lina Teng