Title:
BALL SCREW DEVICE AND ELECTRIC POWER STEERING DEVICE
Document Type and Number:
Japanese Patent JP2019218971
Kind Code:
A
Abstract:
To provide a ball screw device which can make the movement of balls smooth.SOLUTION: A ball screw device comprises a screw shaft, a nut, a plurality of balls and an end deflector. The nut has a second screw groove formed at an internal peripheral face, a notch formed at an end face, and a return hole formed at a bottom face of the notch orthogonal to an axial direction of the screw shaft, and penetrating the notch in the axial direction. The end deflector is fit into the notch. The nut comprises a curved face part at a position between the second screw groove out of a side face of the notch and the return hole. In a first cross section for cutting the nut at a plane orthogonal to the axial direction, and passing the second screw groove and the notch, the curve face part includes a portion drawing a circular arc with a point located outside the second screw groove as center in a radial direction with a rotating axis of the nut as a center. The end deflector comprises at least three plane parts being flat surfaces. The three plane parts mutually form angles.SELECTED DRAWING: Figure 9
Inventors:
MAN YUSUKE
KANEKO SHOYA
KANEKO SHOYA
Application Number:
JP2018114911A
Publication Date:
December 26, 2019
Filing Date:
June 15, 2018
Export Citation:
Assignee:
NSK LTD
International Classes:
F16H25/22; B62D5/04; F16H25/20; F16H25/24
Domestic Patent References:
| JP2015105710A | 2015-06-08 | |||
| JP2003120784A | 2003-04-23 | |||
| JP2013231456A | 2013-11-14 | |||
| JP2007218278A | 2007-08-30 |
Foreign References:
| CN104295688A | 2015-01-21 |
Attorney, Agent or Firm:
Sakai International Patent Office