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:
Aug. 23, 1988
Filed:
Aug. 03, 1987
John F Yonker, Frankenmuth, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
An auxiliary pump system for providing detent pressure in a detent-type variable effort power steering system. The auxiliary pump system includes a gerotor-type auxiliary pump mounted on the transmission of the vehicle and driven at a speed proportional to vehicle speed. The primary power steering pump supplies power steering fluid to the power steering gear and all of the power steering fluid exhausting from the steering gear is directed to the intake of the auxiliary pump. The auxiliary pump produces detent pressure when the vehicle is in motion proportional to vehicle speed and the overage of power steering fluid is directed back to the power steering pump reservoir. From a cold start, the power steering fluid consumed by the auxiliary pump heats faster due to passage through the power steering pump than if drawn directly from the reservoir thereby to minimize the duration during which detent pressure is susceptible to viscosity induced pressure instability.