Nsk Corporation

Nsk Precision Co., Ltd.

Nobuhide Kurachi

Masaru Akiyama

Soichiro Kato

Jun Matsumoto

Hiroki Yamaguchi

Toshio Yoshida

Yoshinori Mizumura

Takayuki Yabe

Ken Namimatsu

In a linear guide device, a rolling element cageholding balls interposed between a rail side rolling element rolling groove and a slider side rolling element rolling groove is formed of a synthetic resin material, and has two plate partsfacing to each other with a slider body being held therebetween. The rolling element cagehas a positioning part that makes contact with the inside surface of the slider body and is positioned on the slider body by the positioning part with respect to the slider.

Linear guide device

A slider has a slider main body which has a circulation sleeve whose inner portion forms a rolling element passage by being inserted into a hole penetrating in an axial direction, an end cap which has an outer peripheral track face of a direction changing passage in a curved shape for communicating a load track between two rolling element rolling grooves and the rolling element passage, and is fixed to an axial end portion of the slider main body, and an inner peripheral track member which has an inner peripheral track face of the direction changing passage, and is fitted to the end cap. An end portion of the circulation sleeve is provided with a plurality of positioning projected portions, and the end cap and the inner peripheral track member are provided with recess portions fitted with the positioning projected portions.

Linear guide

A linear guide device has a retaining piece () between two adjacent rollers (). The retaining piece () has a retaining piece body () having left side-face section and a right side-face section that are parallel to the end face sections of the rollers (), a first arm section () extending from the left side-face section of the retaining piece body () toward the end face sections of the two adjacent rollers () and fitting in a first guide groove () formed in one wall surface section of a circulation path (), and a second arm section () provided on the right side-face section of the retaining piece body () so as to be parallel to the first arm section () and fitting in a second guide groove () formed in the other wall surface section of the circulation path (). The heights of the retaining piece body () and the arm sections () satisfy the conditional expression of (H&#x2212;H)/2&#x3c;(Dw&#x2212;W)/2, where His the height of the retaining piece body (), in the direction perpendicular to the axial direction of a roller; Hthe height of the arm sections () in the direction perpendicular to the axial direction of the roller; W the width of the guide grooves () in the direction perpendicular to the axial direction of the roller; and Dw the diameter of the roller ().

A separator for use in a linear guide apparatus including a guide rail, a slider, and a plurality of rollers which circulate along an endless circulation passage provided in the guide rail and the slider and having guide grooves. The separator includes a separator body interposed between the rollers and having a pair of roller contact surfaces respectively opposing outer peripheral surfaces of the adjacent rollers, and a pair of arm portions which are guided by the guide grooves. A surface of each of the arm portions opposing the guide groove is formed such that an opposition distance with respect to the guide groove becomes wider from a fixed end side of the arm portion toward a free end thereof.

Separator and linear guide apparatus

Rolling element holding members have two holding window for holding rolling elements in rolling element running channels formed between both track faces of a rail and a slider. Further, the rolling element holding members are held between two end caps fixed opposite end surfaces of the slider by engagement of four retaining grooves formed on the end caps and opposite end portions of the rolling element holding members.

Linear guide apparatus

A ball screw includes a screw shaft 2 having an external ball-screw thread 2a, at least one ball nut 3 having an internal ball-screw thread which is opposite to the external ball-screw thread 2a of the screw shaft 2, a spiral raceway formed by combination of the internal ball-screw thread of the ball nut 3 and the external ball-screw thread 2a of the screw shaft 2, a plurality of balls which are circulated through the spiral raceway, and ball return paths 5, 6, and 7 for the plurality of balls. The ball screw also includes three or more circulation circuits X, Y, Z made by the spiral raceway and the ball return paths 5, 6, and 7 formed in the ball nut 3. Of the three or more three circulation circuits X, Y, Z, at least two circulation circuits are arranged so as to be in phase with each other in the circumferential direction of the ball screw 3, and the remaining circulation circuit is positioned so as to be 180 degree out of phase with the two circulation circuits in the circumferential direction. Accordingly it is possible to provide a compact ball screw having heavy load carrying capacity without increasing the size of the ball screw by averaging dispersions in the distribution of loads on the ball screw, and by reducing stress concentrated on the balls placed in a specific position.

Ball screw

In a thin-wall type ball nut of a light-weight type ball screw having a trunnion structure in which a pair of trunnion shafts are extended from the ball nut in the opposite directions; a pair of ribs for increasing the wall thickness of the ball nut are formed on both side surfaces of the ball nut in such a manner that the ribs are extended from the base portions of the trunnion shafts along the axis of the ball nut, so as to increase the rigidity of the portions of the nut body which are liable to be deformed, thereby to prevent the ball nut from deformation.

Growing community of inventors

Fujisawa, Japan

Nobuhide Kurachi