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. 20, 1997
Filed:
Jun. 07, 1995
Lawrence R Folsom, Pittsfield, MA (US);
Clive Tucker, Pittsfield, MA (US);
Folsom Technologies, Inc., Pittsfield, MA (US);
Abstract
A method of pumping at a variable delivery flow rate and pressure includes rotating a pump rotor having a plurality of radially extending vanes inside a flexible cam ring with an input shaft and sweeping a swept volume within the flexible cam ring with the vanes while contacting an inside surface of the flexible cam ring with outside edges of the vanes. The swept volume is sealed on opposite axial sides thereof with a port plate on one side and a side seal plate on the side opposite the port plate, and opposite sides of the flexible cam ring and the vanes are engaged with the plates. Fluid is drawn into the swept volume within the cam ring through a first set of ports in the port plate by rotating the vanes into a suction region within the cam ring having an increasing radius in the direction of the vane rotation. The fluid is pressurized in a pressure region having a decreasing radius in the direction of vane rotation by rotating the vanes into a decreasing volume of the pressurizing region within the cam ring between the intake port and an abutment on the cam ring sealed to a output rotor, and the pressurized fluid is exhausted through a second set of ports in the port plate, circumferentially offset from the first set of ports. The delivery flow rate and pressure is varied by changing the cam ring cross-sectional shape from a round elliptical shape to a flatter elliptical shape by radially flexing the cam ring. The cam ring is flexed by exerting an inward radial force on the cam ring by moving at least one axial control rod positioned radially outside the cam ring in an axial direction, and converting the axial motion of the control rod into a radial force exerted on the cam ring of sufficient magnitude to flex the cam ring.