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Patent Searching and Data


Title:
ELECTRIC POWER STEERING APPARATUS
Document Type and Number:
WIPO Patent Application WO/2019/092998
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide a low-noise power steering apparatus. An electric power steering apparatus of the present invention comprises: a rack 6 having a rack-side ball screw groove 21 formed in a spiral shape; a nut 22A having a nut-side ball screw groove 23 formed in a spiral shape; and a plurality of balls 24 arranged in a ball circulation groove that is constituted by the rack-side ball screw groove 21 and the nut-side ball screw groove 23. Assuming that the nut-side ball screw groove 23 is divided into three ranges including a first range R1, a second range R2, and a third range R3 so that each range has a central angle of 120° in a continuous range with a central angle of 360° of the nut-side ball screw groove 23 and the three ranges do not overlap with each other, the first range R1, the second range R2, and the third range R3 in the nut 22A have thick regions T1, T2, and T3 extending in the radial direction and having mutually different thickness, respectively.

Inventors:
WATANABE MASANORI (JP)
TANABE YOSUKE (JP)
SHIINO KOTARO (JP)
Application Number:
PCT/JP2018/035374
Publication Date:
May 16, 2019
Filing Date:
September 25, 2018
Export Citation:
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Assignee:
HITACHI AUTOMOTIVE SYSTEMS LTD (JP)
International Classes:
B62D5/04; F16C33/64; F16H7/02; F16H19/04; F16H25/22; F16H25/24
Foreign References:
JP2003097661A2003-04-03
JP2017007587A2017-01-12
KR20120139966A2012-12-28
DE102013010012A12014-12-18
CN106870667A2017-06-20
Attorney, Agent or Firm:
POLAIRE I. P. C. (JP)
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