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. 22, 1987
Filed:
Sep. 11, 1986
John G Schaefer, Rockford, IL (US);
Jerome K Aarestad, Rockford, IL (US);
Terry L Whitesel, Rockford, IL (US);
Sundstrand Corporation, Rockford, IL (US);
Abstract
A centrifugal pump has a casing with an impeller cavity in which a shrouded impeller is mounted and with front and rear labyrinth seals associated one with each of the front and rear shrouds of the impeller and located near the inner ends of the shrouds. An additional seal is positioned inwardly of the rear labyrinth seal to substantially seal a space behind the innermost part of the rear shroud and a pump structure is mounted on the impeller to the rear of the rear shroud for pumping fluid from the substantially sealed space to the entrance of a volute surrounding the impeller. The impeller shaft has a front thrust bearing coacting with a bearing surface, with fluid passing therebetween for lubrication and with the flow of the fluid being controlled to a minimal amount by a force imbalance on the impeller shaft created by location of the front and rear labyrinth seals at different distances from the axis of rotation of the impeller whereby pressure forces acting at the rear of the impeller urge the impeller shaft in a forward direction.