Ball screw device
AssigneeNtn Corporation
InventorsShintarou Ishikawa, Yoshinori Ikeda
Life of this patent
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Abstract
A ball screw device includes a nut including a nut main body and a cover, a screw shaft, a rolling path formed by a screw groove of the nut main body and a screw groove of the screw shaft, a circulation path formed by an outer circumferential surface of the nut main body and the cover, a pair of connection paths that allow one end of the circulation path and one end of the rolling path to be communicated with each other and allow the other end of the circulation path and the other end of the rolling path to be communicated with each other, respectively, and a large number of balls disposed in the rolling path, the circulation path, and the pair of connection paths. The circulation path is formed along a cylindrical path of the outer circumferential surface of the nut main body.
Claims13
A ball screw device comprising:
- a nut including a nut main body having a screw groove on an inner circumference thereof and a circulation path forming member fixed to an outer circumferential surface of the nut main body;
- a screw shaft having a screw groove on an outer circumference thereof;
- a rolling path formed by the screw groove of the nut main body and the screw groove of the screw shaft;
- a circulation path formed by the outer circumferential surface of the nut main body and the circulation path forming member;
- a pair of connection paths that allow one end of the circulation path and one end of the rolling path to be communicated with each other and allow another end of the circulation path and another end of the rolling path to be communicated with each other, respectively;
- and
- a plurality of balls disposed in the rolling path, the circulation path, and the pair of connection paths,
- wherein the circulation path is formed in an arch shape along a cylindrical portion of the outer circumferential surface of the nut main body,
- wherein a pair of through holes is formed in the nut main body, the pair of through holes functioning as the pair of connection paths,
- wherein the circulation path is formed by a circulation groove formed in the cylindrical portion of the outer circumferential surface of the nut main body and a groove provided on the circulation path forming member,
- wherein the circulation path forming member comprises a portion forming the groove, the portion forming the groove covering the circulation groove and the through holes of the nut main body from an outer diameter side, and
- wherein an entirety of the portion forming the groove is provided on an outer diameter side of the cylindrical portion of the nut main body.
Dependencies are inferred from the claim text.