Kuroda Precision Industries Ltd.

Yoshimi Iwasaki

Ryo Kaibe

Hitoshi Hakogi

Tatsuto Omori

An end deflector includes a main portion including a ball delivery path that delivers balls between a rolling path and a ball return path, a tongue portion that guides the balls from the rolling path to the ball delivery path, and a pair of protruding pieces, that extend in the circumferential direction of each nut body from either side of the tongue portion with respect to the axial direction and define a ball guide groove that extends between the ball delivery path and the rolling path in cooperation with an inner circumferential surface of a deflector holding recess formed in a nut body, the main portion has an outer circumferential surface which opposes an inner circumferential surface of the deflector holding recess in the radial direction, a front-side portion of the outer circumferential surface with respect to a direction of insertion into the deflector holding recess is offset inward in the radial direction, and at least a rear-side portion of the outer circumferential surface with respect to the direction of insertion into the deflector holding recess is fitted to the inner circumferential surface of the deflector holding recess.

Ball screw

To prevent the positional precision of the ball return passage and the tongue of the end deflector relative to the nut main body from being impaired by an axial force applied by a screw used for securing the end deflector to the nut main body, the end deflector includes a flange () provided at an axial end of a main part () of the end deflector and provided with an axial through hole () for receiving a screw which is threaded into the nut main body, and a rib () projecting from a radially inner edge of the flange to an inner side of the deflector receiving recess ().

In a multi-piece deflector for a ball screw mechanism, the positioning precision of a tongue with respect to a ball rolling passage can be improved, balls can be recirculated in a proper manner at all times, and damages to the tongue can be avoided. A deflector main body () which is fitted to the nut () is provided with a tongue () and a main body side ball guide groove () defining a part of a circular cross section, and a component piece () which is fitted to the deflector main body () is provided with a component piece side ball guide groove () defining a remaining part of the circular cross section.

Deflector for ball screw mechanism and ball screw mechanism

In a plastic nut for a ball screw formed by injection molding fiber reinforced plastic, the reduction in precision over time due to wear is minimized. A thread groove is ground until the fibers in matrix plastic are exposed on the surface of the thread groove.

Plastic nut for ball screw and method for manufacturing same

In a ball screw (), the positioning of the deflectors to the nut is facilitated, and the deflectors are prevented from being dislodged in the radially outward direction from the nut. The ball screw () includes a screw shaft (), a nut (), a pair of deflectors () inserted in respective receiving holes () of the nut and a plurality of balls (). The nut () is provided with a guide portion () configured to cooperate with a corresponding guide portion () provided on the deflector () so that the insertion of the deflector () into the respective receiving holes () is guided in a direction at an angle to the radial direction of the nut.

In a ball screw (), comprising a screw shaft (), a nut () threaded onto the screw shaft via a plurality of balls () received in a raceway () defined between the two parts, an end deflector receiving recess () is formed on each axial end thereof to complementarily receive an end deflector () which defines a part of the raceway in cooperation with an opposing part of the nut, wherein the end deflector is provided with a pair of engagement claws () that engage corresponding parts of the thread () formed on the nut. Thereby, the need for a special engagement feature or other arrangement for attachment is eliminated, and still a highly firm and accurate engagement is ensured between the nut and the end deflector.

Ball screw with an improved end deflector

The invention provides a ball screw lubricative sealing device having a simplified lubrication mechanism. It is attachable to an installed standard ball screw nut, capable of retaining larger amount of lubricant and long supply of lubricant to the contacting screw parts, and further includes a sealing function. It includes: generally cylindrical case members having attachment part to be attached to both ends of a screw nut, respectively; plural thin seal plates made of lubricating oil impregnated felt-like fiber material which is a three-dimensionally crosslinked plastic fiber and resilient rubber members, and having a hole each and fitted inside said case member in such a state that they circumferentially overlap with each other, the hole having a shape corresponding to a lateral cross-sectional shape of a screw groove of ball screw shaft; and a plastic wiper fitted with a space from the thin seal plates inside each of the case member.

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Kisarazu, Japan

Yoshimi Iwasaki