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:
Apr. 22, 2008
Filed:
Mar. 18, 2004
Toshikazu Yabe, Fujisawai, JP;
Takeshi Murakami, Fujisawa, JP;
Toshimi Takajo, Fujisawa, JP;
NSK Ltd., Tokyo, JP;
Abstract
An electric power steering device having a resin gear used in a speed reduction gear mechanism and the resin gear used for the device are provided. The speed reduction gear mechanism includes a driven gear that is the resin gear integrally formed by fitting a resin part having gear teeth formed on the outer peripheral surface thereof to the outside of a metal core and a drive gear meshed with the driven gear. The resin part of the resin gear is formed of a resin composition having, as a base resin, a polyamide resin containing 10 to 50% by weight of glass fiber of 5 to 9 μm in diameter, and has excellent wear resistance, durability, and dimensional stability. Grease on the meshed surfaces of the gears has such a composition that includes a thickener and 3 to 10% by weight of a wax having a melting point or softening point in the range of 70 to 130° C. in a base oil formed mainly of at least one oil selected from mineral oil, poly α-olefin oil, and alkyl polyphenyl ether.