Ball screw
AssigneeNsk Ltd.
InventorTsutomu Ohkubo
Life of this patent
Estimating the term…
Abstract
The ball scooping position of a ball is setted downwardly of a reference line and the angle of the ball scooping position with respect to the reference line is setted at an angle of −15°. The end face of the rising portion of a tube is disposed so as to coincide with the reference line. The axis of the rising portion is setted so as to be present outside of a line corresponding to the ball center locus of a raceway. The inner surface of the pickup portion of the tube is connected with the ball scooping position of the ball rolling groove of a nut by a surface which exists outside of the ball rolling groove of the nut.
Claims6
A ball screw, comprising:
- a screw shaft including a spiral-shaped ball rolling groove formed on an outer peripheral surface thereof;
- a nut including a spiral-shaped ball rolling groove which is corresponded to said spiral-shaped ball rolling groove formed on said screw shaft so as to form a raceway therebetween and is formed in an inner peripheral surface thereof;
- a plurality of balls respectively disposed within said raceway defined by said two spiral-shaped ball rolling grooves;
- and
- a tube for circulating said balls from one end side of said raceway to the other end side thereof and including rising portions which are disposed in a rising direction from said raceway, said tube being connected to said one end side of said raceway and the other end side thereof via said rising portions respectively;
- wherein an architectonic ball scooping position, where said balls are released from a loaded rolling portion formed in said raceway, is positioned on or in adjacent to a reference line that is perpendicular to said rising direction of said rising portion and passing through an axial core point of said screw shaft;
- and
- wherein said tube is disposed in such a manner that the axis of said rising portion presents at a nut-side outside of a line corresponding to a ball center locus of said raceway in the diameter direction.
Dependencies are inferred from the claim text.