Nsk Corporation

Nsk Precision Co., Ltd.

Nnsk Ltd.

Takayuki Yabe

Masato Kato

Toshiaki Suzuki

Yoshinori Mizumura

Nobuhide Kurachi

Toshiharu Kajita

Junji Minakuchi

Wei Xu

Hideyuki Sato

Yuto Suzuki

Yusuke Watarai

Kyohei Ikeda

Masato Katou

A ball screw device includes: a nut having a first track path; an outer circumferential screw shaft having a second track path and a third track path; a plurality of first balls disposed between the first track path and the second track path; an inner circumferential screw shaft having a fourth track path; a plurality of second balls disposed between the third track path and the fourth track path; a first stopper fixed closer to an end of the outer circumferential screw shaft in a first direction; a second stopper fixed closer to an end of the inner circumferential screw shaft in a second direction; and a third stopper fixed closer to an end of the outer circumferential screw shaft in the second direction. The track of the first ball and the track of the second ball are helixes running in a same direction.

Ball screw device

In a multi-row bearing, an inner ring raceway groove at one end portion in an axial direction is formed over groove shoulders on both sides in the axial direction with respect to a groove bottom, and an inner ring raceway groove at an intermediate portion in the axial direction is formed over a groove shoulder on one side in the axial direction from a groove bottom. In addition, an outer ring raceway groove at the other end portion in the axial direction is formed over groove shoulders on both sides in the axial direction with respect to a groove bottom, and an outer ring raceway groove at the intermediate portion in the axial direction is formed over a groove shoulder on one side in the axial direction from a groove bottom.

Multi-row bearing and bearing unit

A nut of a ball screw is formed with, in a notch portion, an elongated hole that penetrates in a radial direction, and whose longitudinal direction is formed along a lead angle and parts of both longitudinal side surfaces parallel to each other guide balls. A circulation part includes: a first circulation component that is disposed in the notch portion so as to abut against a bottom wall surface of the notch portion and has a tongue portion accommodated in the elongated hole; a second circulation component that is disposed in the notch portion so as to cover the first circulation component and accommodated in the elongated hole, and has a wall portion facing the tongue portion; and a higher strength pipe that is disposed in an abutting surface where the first and second circulation components abut against each other, constitutes a part of a ball circulation path.

Ball screw

A method of manufacturing a ball screw device includes a nut unit preparation step, a screw shaft preparation step, and an assembly step. In the nut unit preparation step, a nut unit is prepared in which a circulation component, a ball, and a temporary shaft that prevents the ball from falling off are assembled to a nut provided with an inner peripheral track surface. In the screw shaft preparation step, a screw shaft provided with an outer peripheral track surface is prepared. In the assembly step, after the nut unit preparation step and the screw shaft preparation step, the temporary shaft of an arbitrary nut unit is replaced with an arbitrary screw shaft to manufacture the ball screw device.

Method of manufacturing ball screw device

A multi-row ball screw includes a nut having a plurality of spiral grooves on an inner peripheral surface thereof, a screw shaft having a plurality of spiral grooves on an outer peripheral surface thereof, and a plurality of balls disposed so as to be rollable on rolling paths constituted by the plurality of spiral grooves of the nut and the plurality of spiral grooves of the screw shaft. The spiral groove of the nut includes a U-shaped first spiral groove having left and right flanks that are respectively able to come into contact with two-row balls and separated from each other in an axial direction, and two second spiral grooves continuous with each row of the first spiral groove and each having left and right flanks that are able to come into two-point contact with the ball.

Multi-row ball screw

A ball screw devicecapable of increasing a load capacity by increasing the size of ball diameter and the number of threads by preventing the cutout of a nut from being interfered with a thread groove adjacent to the cutout even in the thread groove of a small lead screw and a multiple thread screw, wherein a circulating blockforming, in association with the cutout, a ballcirculation passagefor communicating an area between both thread groovesandwith a ball return passageis fitted to the cutoutformed at the end of the nutso that the large number of ballscan be endlessly circulated between both thread groovesand, ball circulation passage, and ball return passage. The face of the cutoutfacing the axial direction thereof is used as a ball running surface, a ball circulating grooveis formed at the portion of the circulation blockopposed to the ball running surface, and the ball circulation passageis formed of the ball circulating grooveand the ball running surface

A ball screw device has a screw shaft which has a shaft rolling groove in a spiral shape formed on an outer surface of the screw shaft, a nut which has a nut rolling groove formed on an inner surface of the nut and opposed to the shaft rolling groove, wherein the screw shaft is to be screwed in the nut so that the shaft rolling groove and the nut rolling groove are faced through a plurality of rolling balls, and a lubrication ring which is made of a lubricant-including material, comes in slide contact with the screw shaft, and is arranged in an end portion of the nut, wherein a non-contact portion, which does not come in slide contact with the screw shaft, is formed on the slide contact surface of the lubrication ring.

A ball screw has a screw shaft including a screw groove formed in an outer peripheral surface thereof; a nut including a screw groove formed in an inner peripheral surface thereof and screwed together with the screw shaft through a large number of balls rollably disposed in a spiral-shaped ball rolling passage formed by the two screw grooves; and, two seals respectively disposed on the two end portions of the nut for sealing the opening of a clearance between the screw shaft and the nut, wherein two annular grooves are respectively formed in the inner peripheral surfaces of the two end portions of the nut, each of the seals is formed in a substantially annular-ring shape having an outside diameter larger than the inside diameter of the nut and the seals are mounted into the nut by fitting the outer edge portions of the seals into the annular grooves.

Linear guide apparatus

A ball screw apparatus, has a screw shaft including a screw groove; a nut fitted with the screw shaft, the nut including a screw groove and a ball return passage; a circulation piece including a ball circulation passage; and, a large number of balls, wherein, in the inner peripheral surface of the nut, a concave-shaped snap ring groove extending along the peripheral direction of the nut is formed, in the face of the circulation piece that faces the inside diameter side of the nut, a concave-shaped snap ring groove is formed so as to connect to the snap ring groove of the nut, and an outside diameter portion of a snap ring is fitted into the two snap ring grooves to thereby fix the circulation piece to the nut.

Ball screw apparatus

One end of a cylinder disposed on the outer periphery of a ball screw shaft is fixed to the end face of a ball nut, while the other end of the cylinder is closed by an end plate to thereby form a lubricant filling space between the end plate and the leading end face of the ball screw shaft. And, the lubricant is supplied into the lubricant filling space from a grease nipple mounted on the cylinder.

A ball nut has a dowel for circulating balls . A cage type retainer is disposed between a screw shaft and the ball nut which engages with the screw shaft through the ball . The retainer is provided with a plurality of elongated holes at a peripheral surface thereof to extend to an axial direction thereof so as to separate the balls from one another in a peripheral direction thereof and to hold the balls therein to be free to roll. The distance of a space between the screw shaft and the cage type retainer is set to be smaller than that of a space between the dowel and the cage type retainer n the radial direction of the screw shaft.

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.

An automotive vehicle equipped with an air bag system includes an interior gas discharge device for communicating a vehicle interior to the outside upon detection of a vehicular collision and a forced ventilation device provided for operation upon detection of the vehicular collision.

Growing community of inventors

Gunma, Japan

Takayuki Yabe