CN-116006646-B - Ball screw

CN116006646BCN 116006646 BCN116006646 BCN 116006646BCN-116006646-B

Abstract

The invention relates to a ball screw, an end deflector (16) includes a main portion (30) including a ball delivery path (36) that delivers balls (28) between a rolling path (20) and a ball circulation path (24), a tongue portion (38) that guides the balls from the rolling path to the ball delivery path, and a pair of protruding piece portions (42, 44) that define ball guide grooves (40) extending between the ball delivery path and the rolling path in cooperation with an inner peripheral surface of a deflector holding recess (26) formed in a nut body so as to extend from both sides of the tongue portion in an axial direction to a circumferential direction of the nut body (14), respectively. The main part has an outer peripheral surface (30A) of an inner peripheral surface (54B). A front side part (30 Aa) of the outer peripheral surface in the insertion direction relative to the deflector holding recess is offset radially inward. At least the rear side (30 Ab) of the outer peripheral surface in the insertion direction relative to the deflector holding recess is fitted into the inner peripheral surface of the deflector holding recess.

Inventors

Hai Bulian
Xiang Mujun
IWASAKI YOSHIMI
Dasen Daden

Assignees

黑田精工株式会社

Dates

Publication Date: 20260505
Application Date: 20171225

Claims (2)

1. A ball screw, the ball screw comprising: a screw shaft having an outer peripheral surface on which a shaft-side thread groove is formed; A nut body having an inner peripheral surface on which a nut-side screw groove is formed, a ball return path extending in an axial direction, and an end surface provided with a deflector holding recess in which an axial end of the ball return path opens, the nut-side screw groove being formed opposite to the shaft-side screw groove to define a rolling path in cooperation with the shaft-side screw groove; a plurality of balls rollably accommodated in the rolling path and the ball return path, and An end deflector inserted into the deflector holding recess, wherein, The end deflector has a main portion including a ball delivery path that delivers the balls between the rolling path and the 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 from both sides of the tongue portion in the axial direction toward the circumferential direction of the nut body, respectively, and define a ball guide groove that extends between the ball delivery path and the rolling path in cooperation with an inner peripheral surface of the deflector holding recess, and A front side portion of an outer peripheral surface of the main portion in a radial direction opposite to an inner peripheral surface of the deflector holding recess with respect to an insertion direction of the deflector holding recess is offset to a radial inner side of the main portion, and a rear side portion of the outer peripheral surface of the main portion in at least the insertion direction of the deflector holding recess is fitted with the inner peripheral surface of the deflector holding recess, Wherein the end deflector includes a flange portion provided at an axial end portion of the main portion and is fixed to the nut body by a mounting screw penetrating the flange portion in the axial direction to be in threaded engagement with the nut body, and further includes a rib extending from a radially inner edge of the flange portion in a direction toward a depth side of the deflector holding recess, The flange portion includes a radial flange portion extending radially outward from an end of the main portion and including a portion that is integral with one of the pair of protruding pieces on a flange portion side, and a circumferential flange portion extending from the end of the main portion in a circumferential direction opposite to a protruding direction of the one protruding piece, and the rib portion is provided on the circumferential flange portion.
2. The ball screw according to claim 1, wherein the rib includes a portion overlapping the inner peripheral surface of the nut body in the radial direction in a planar shape.

Description

Ball screw The application is a divisional application of an application patent application (International application No. PCT/JP2017/046403, application date: 2017, 12, 25, title of application: ball screw) with an original application number 201780092369.1. Technical Field The present invention relates to a ball screw, and more particularly, to a ball screw including an end deflector attached to a nut body. Background As a ball screw for a linear moving mechanism or the like, there is known a ball screw including a screw shaft having an outer peripheral surface on which a shaft-side thread groove is formed, a nut body having an inner peripheral surface on which a nut-side thread groove is formed, the nut-side thread groove being formed opposite to the shaft-side thread groove so as to define a rolling path in cooperation with the shaft-side thread groove, a ball return path extending in an axial direction, and an end surface provided with a deflector retaining recess continuous with the nut-side thread groove and in which an axial end of the ball return path opens, a plurality of balls rollably accommodated in the rolling path and the ball return path, an end deflector inserted into the deflector retaining recess and having a ball delivery path for delivering the balls between the rolling path and the ball return hole and a tongue portion guiding the balls from the rolling path to the ball delivery path, and mounting screws penetrating the end deflector in the axial direction to engage with the body thread to fix the end of the nut body to, for example, patent document 1 (patent document 4). List of references Patent literature Patent document 1 Japanese patent laid-open No. 2007-24305 Patent document 2 Japanese patent application laid-open No. 2013-174316 Patent document 3 Japanese patent application laid-open No. 2014-16039 Patent document 4 Japanese patent application laid-open No. 2014-77459 Disclosure of Invention Technical problem When the fitting clearance between the deflector holding recess and the end deflector is reduced so as to improve the accuracy of the assembled position of the end deflector with respect to the nut body, workability of aligning and inserting the end deflector into the deflector holding recess is deteriorated. As described in patent document 4, in the case where the end deflector is provided with a pair of protruding pieces that extend from both sides in the axial direction of the tongue portion toward the circumferential direction of the nut body, respectively, to define a ball guide groove that extends between the ball delivery path and the rolling path in cooperation with the inner peripheral surface of the deflector holding recess portion, the protruding pieces may be damaged by collision against the nut body when the end deflector is assembled to the nut body, resulting in a reduction in yield. The problem to be solved by the present invention is to improve workability of assembling an end deflector to a nut body and avoid a reduction in yield while ensuring accuracy of assembling the end deflector to the nut body in a ball screw. Technical proposal The ball screw according to one embodiment of the present invention includes a screw shaft having an outer peripheral surface on which a shaft-side thread groove is formed, a nut body having an inner peripheral surface on which a nut-side thread groove is formed, a ball return path, and an end surface, the nut-side thread groove being formed opposite the shaft-side thread groove to define a rolling path in cooperation with the shaft-side thread groove, the ball return path extending in an axial direction, the end surface being provided with deflector retaining recesses in which axial ends of the ball return path open, a plurality of balls rollably accommodated in the rolling path and the ball return path, and an end deflector inserted into the deflector retaining recesses, wherein the end deflector has a main portion including a ball delivery path for delivering balls between the rolling path and the ball return path, a tongue portion for guiding the balls from the rolling path, and a pair of protruding piece portions extending in the axial direction from both sides of the main portion in the tongue portion in the axial direction, and a portion of the main portion being retained in cooperation with the deflector retaining recesses in the inner peripheral surface, and a portion of the deflector retaining recesses extending in the radial direction, and the end deflector retaining recesses being retained in the opposite the inner peripheral surface of the deflector retaining recesses, and the end deflector retaining recesses being inserted into the main peripheral surface. According to this configuration, the insertion of the end deflector into the deflector holding recess is performed by first inserting the front side portion of the outer peripheral surface of the main portion into the rear side portion of the inner periphera