Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.

Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.

Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.

Abstract: The invention relates to a ball screw device in which a screw shaft and a nut member are threadedly engaged with each other through a number of balls. In such a ball screw device, an inner surface of a cover plate contacting an end surface of a nut main body is provided with a projecting return piece adapted to be fit-engaged with a recess cut in an inner peripheral surface of the nut main body, the return piece being provided with a scoop portion for dislodging the balls from the ball rolling groove of the screw shaft and a direction switching passage for guiding the dislodged balls to the entrance of a ball return hole. The projecting return piece is divided into a first piece formed integral with the cover plate and a second piece fixed to the first piece by a curved plane including the center line of the direction switching passage.

Abstract: There is provided a rolling element spacer used in a rolling guide device having an endless circulation passage of balls, arranged alternately with many balls in the endless circulation passage, and circulating together with the balls in the endless circulation passage. It has a pair of ball holding seats each of which is formed in a concave spherical face form nearly approximating a spherical face of the ball and sliding-contacts with the ball and, around each ball holding seat, there is formed an annular dropout prevention portion protruding in a ball arranging direction than an edge portion of the ball holding seat and kept in non-contact with respect to the ball seated on the ball holding seat.

Abstract: A roller retainer 11 encloses an outer periphery of the roller 9 situated on a diagonal 20 when the roller 9 is viewed from the side surface thereof. Whether the rollers 9 are arranged in a parallel manner or in a cross manner, the roller retainer 11 is able to keep a constant position and thus the disposition of the roller retainer 11 is free from the influence of the direction the roller 9. Also, since the roller retainer 11 restricts a corner portion 9a of the roller 9, the roller 9 is difficult to slip off the roller retainer 11 and thus the roller 9 can be restricted positively, thereby being able to control the skew of the roller 9.

Abstract: There is provided a rolling element spacer used in a rolling guide device having an endless circulation passage of balls, arranged alternately with many balls in the endless circulation passage, and circulating together with the balls in the endless circulation passage. It has a pair of ball holding seats each of which is formed in a concave spherical face form nearly approximating a spherical face of the ball and sliding-contacts with the ball and, around each ball holding seat, there is formed an annular dropout prevention portion protruding in a ball arranging direction than an edge portion of the ball holding seat and kept in non-contact with respect to the ball seated on the ball holding seat.

Abstract: The present invention provides rolling element spacers used in a rolling guide unit provided with an endless circulating passage for balls; arranged with plural balls alternately therewith in the endless circulating passage; and circulated with these balls in the endless circulating passage. Each of the rolling element spacers has a pair of retaining seats which the balls contact, and is formed so that, on a ball cutting plane perpendicular to the center of rotation of each ball, each retaining seat and a relative ball contact each other at only the two portions of the retaining seat that are in the vicinity of both ends thereof.

Abstract: The present invention provides rolling element spacers used in a rolling guide unit provided with an endless circulating passage for balls; arranged with plural balls alternately therewith in the endless circulating passage; and circulated with these balls in the endless circulating passage. Each of the rolling element spacers has a pair of retaining seats which the balls contact, and is formed so that, on a ball cutting plane perpendicular to the center of rotation of each ball, each retaining seat and a relative ball contact each other at only the two portions of the retaining seat that are in the vicinity of both ends thereof.

Abstract: A roller retainer 11 encloses an outer periphery of the roller 9 situated on a diagonal 20 when the roller 9 is viewed from the side surface thereof. Whether the rollers 9 are arranged in a parallel manner or in a cross manner, the roller retainer 11 is able to keep a constant position and thus the disposition of the roller retainer 11 is free from the influence of the direction the roller 9. Also, since the roller retainer 11 restricts a corner portion 9a of the roller 9, the roller 9 is difficult to slip off the roller retainer 11 and thus the roller 9 can be restricted positively, thereby being able to control the skew of the roller 9.

Abstract: There is provided a rolling element spacer used in a rolling guide device having an endless circulation passage of balls, arranged alternately with many balls in the endless circulation passage, and circulating together with the balls in the endless circulation passage. It has a pair of ball holding seats each of which is formed in a concave spherical face form nearly approximating a spherical face of the ball and sliding-contacts with the ball and, around each ball holding seat, there is formed an annular dropout prevention portion protruding in a ball arranging direction than an edge portion of the ball holding seat and kept in non-contact with respect to the ball seated on the ball holding seat.

Abstract: There is provided rolling element spacers that are used in a rolling guide device having an endless circulation path of balls and that are arranged to alternate with a multiplicity of balls and circulated in the endless circulation path along with the balls. They are constituted by a disc-shaped inner member having a pair of ball holding seats on which the balls slide in contact therewith and an annular outer member covering an outer circumferential surface of the inner member, and the outer member and inner member are molded from resin materials having different flexural modulo.

Abstract: There is provided a rolling element spacer used in a rolling guide device having an endless circulation passage for balls, arranged alternately with many balls in the endless circulation passage, and circulating together with the balls in the endless circulation passage. In order to prevent the rolling element spacer from falling sideways and avoid a trouble such as malfunction of the rolling guide device, the rolling element spacer is formed such that its diagonal dimension in a thickness direction becomes larger than an inner diameter of the endless circulation passage.