Title:
BALL SCREW DEVICE, AND ELECTRIC POWER STEERING DEVICE INCLUDING THE SAME
Document Type and Number:
Japanese Patent JP2015034562
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a ball screw device capable of suppressing distortion of a thread groove of a ball screw nut, and to provide an electric power steering device including the same.SOLUTION: A ball screw device 22 includes a ball screw nut 41 provided with a thread groove 46 on its inner periphery, and is constituted by arranging a plurality of balls 42 in a ball raceway R1 where the thread groove 46 and a thread groove 43 formed on an outer periphery of a rack shaft are opposed to each other. The ball screw nut 41 is provided with a male screw portion 49 engaged with a female screw portion 31 of a motor shaft 26. The ball screw nut 41 is screw--fastened so that a seating face 47 is pressed by an axial end face 32 by axial force generated by engaging the male screw portion 49 with the female screw portion 31 and fastening them. A lead of the male screw portion 49 is determined to be continuously decreased from a basic end (seating face 47 side) toward a tip (side opposite to a seating face 47) of the male screw portion 49 in a fixed ratio.
Inventors:
MOTOYAMA SATOSHI
Application Number:
JP2013164437A
Publication Date:
February 19, 2015
Filing Date:
August 07, 2013
Export Citation:
Assignee:
JTEKT CORP
International Classes:
F16H25/24; B62D5/04; F16H25/20; F16H25/22
Domestic Patent References:
| JP2013075546A | 2013-04-25 | |||
| JP2001355625A | 2001-12-26 | |||
| JPS5747016A | 1982-03-17 | |||
| JP2000227109A | 2000-08-15 |
Attorney, Agent or Firm:
Makoto Onda
Hironori Onda
Hironori Onda