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:
Feb. 17, 1987
Filed:
Jul. 02, 1984
Frank A Leachman, Jr, Bristol, CT (US);
Chandler Evans Inc., West Hartfort, CT (US);
Abstract
A vapor core centrifugal fuel pumping system (10') has a main flow impeller (72) and a low flow impeller (81) mounted upon the front plate (74) of the main flow impeller. Both of the impellers receive flow from an inlet passage (26') which proceeds past an inlet throttling valve (114). During pumping operation of the low flow impeller, a surface (122) on the inlet throttling valve forms a labyrinth seal with the radially inner lip (120) of the front plate to reduce inlet fuel flow entering the main impeller. A first check valve (124) and a second check valve (126) respectively prevent flow from the low flow impeller from entering the main flow impeller and flow from the main impeller from entering the low flow impeller. The second check valve is associated with conduits (140, 142) to evaculate liquid adjacent the main impeller during operation of the low flow impeller to reduce windage losses. The pumping system does not engender excessive pressure or flow transients during changeover between low flow operation and normal flow operation. Also, the pumping system imparts minimal temperature rise to the fuel being pumped and is not susceptible to significant cavitation erosion.