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:
Oct. 25, 1994
Filed:
Jan. 27, 1994
Herman P Schutten, Eden Prairie, MN (US);
Danny M Wakefield, Eden Prairie, MN (US);
Donald R Zimmerer, Eden Prairie, MN (US);
David W Malaney, West Bloomfield, MI (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A rotary pump (10) is disclosed of the type including a rotating cylinder block (25) defining a plurality of cylinders (27), each defining an imaginary axis (a), which are uniformly spaced about an axis of rotation (A) of the cylinder block. A piston (29) is disposed for reciprocation within each cylinder (27) as the cylinder block rotates. The housing defines a fluid inlet (43) and a fluid outlet (45). In open communication with each cylinder (27) is a cylinder port (47), disposed for serial communication with the fluid inlet and fluid outlet as the cylinder block (25) rotates. Each cylinder port (47) defines a leading edge (L) which are disposed randomly relative to their respective imaginary axis (a). As a result, the timing of communication between the leading edges of the cylinder ports (47) and the fluid inlet and fluid outlet comprise a non-repetitive pattern, thus substantially reducing the sound level at the second fundamental frequency of the piston frequency, also substantially improving the quality of the sound during operation of the pump.