The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 01, 2008
Filed:
Nov. 11, 2004
Shuji Endo, Gunma, JP;
Yuho Aoki, Gunma, JP;
Shuji Endo, Gunma, JP;
Yuho Aoki, Gunma, JP;
NSK Ltd., Tokyo, JP;
NSK Steering Systems Co., Ltd., Tokyo, JP;
Abstract
In order to solve a problem that a motor generates a noise so as to deteriorate an environment in a vehicle if a field weakening control is executed to the motor of a electric power steering apparatus, in the case that a vehicle speed is high, the same field weakening control as the conventional one is applied to the motor because a noise generated due to a friction between a tire and a road surface and a wind noise of a vehicle body are large, and in the case that the vehicle speed is low, the field weakening control is weakly applied in comparison with the conventional one because the noise generated by the motor is felt relatively largely. Accordingly, the field weakening control can be executed in response to the vehicle speed in such a manner as to make the motor noise smaller.