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:
May. 09, 1989
Filed:
May. 01, 1986
Paul A Sipe, Marshall, MI (US);
Michael D Davis, Coldwater, MI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A balanced rotary pump is disclosed of the type including a pumping element (17) having a rotor member (25) defining a plurality of slots (27). Each of the slots receives a radially displaceable roller vane member (29). The pumping chamber is defined by a pair of inlet arc surfaces and a pair of discharge arc surfaces (65) of progressively decreasing radius. Each of the slots (27) includes a driving surface (73), each of which includes a substantial surface portion (77) oriented at a negative angle relative to a radial line passing through the center of the adjacent roller vane member. The engagement of each of the roller vane members (29) and its respective negative surface portion (77) is effective to act to reduce slightly the net radially outward force acting on the roller vane member, to reduce bouncing thereof as the roller vane member passes from the inlet arc surface to the discharge arc surface. The result is improved engagement of the roller vane member and the adjacent cam surface, reduced leakage past the vane member, and a reduction in pressure pulses and noise.