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:
Dec. 20, 2011
Filed:
Jan. 03, 2008
David R. Shulver, Richmond Hill, CA;
Cezar Tanasuca, Richmond Hill, CA;
Matthew Williamson, Richmond Hill, CA;
David R. Shulver, Richmond Hill, CA;
Cezar Tanasuca, Richmond Hill, CA;
Matthew Williamson, Richmond Hill, CA;
Magna Powertrain Inc., Concord, CA;
Abstract
A variable displacement vane pump provides a substantially constant output pressure in its regulated operation region. A longitudinal axis of the control spring is inclined, with respect to a plane through the rotational axis of a pivot and a contact point between the control ring and the control spring. The inclination reduces the length of the moment arm between the spring and the pivot when the control ring of the pump is moved from the maximum displacement position to the minimum displacement position. The reduced length moment arm offsets the increase in the moment produced by compression of the control spring is offset to achieve a substantially constant output pressure. The control spring is compressed a reduced amount during pump operation to minimize the change in output force exerted by the control spring as the control ring moves between positions.