GB981040A - Improvements in or relating to pumps - Google Patents

Abstract

981,040. Centrifugal pumps. THOMPSON RAMO WOOLDRIDGE Inc. Sept. 3, 1963, No. 34822/63. Heading F1C. In a pump comprising a housing formed with a volute pumping chamber 37 having an axially extending inner wall 38 merging with an inner portion 39, 40 of the housing, which portion extends axially and radially inwardly of the pump and an impeller having a vaned wall 12 and journalled in a bearing 61, 62 mounted in the inner portion of the housing, the vaned wall 12 co-operates with the inner portion of the housing to form an orifice 83 which communicates with the volute pumping chamber to allow leakage therefrom to the bearing for lubricating thereof, and one or more openings 84 through the inner portion of the housing allow leakage from between the vaned wall and the inner portion. The leakage through the orifice 83 also acts as a coolant for the bearing and the openings 84 prevent pressure build-up behind the impeller. The pump is driven by an hydraulic motor 42 and may function as high-speed low-pressure fuel pump of high output or a booster pump and vapour separator, the vapour escaping through holes 94 which are substantially tangential to the impeller casing 21. The leakage passage following the orifice 83 may extend only radially or it may extend initially radially and then turn through a right angle and continue parallel to the rotational axis. The bearing consists of two ball bearings 61 and 62 which are pre-loaded by a spring 63. Vent openings 90 in the impeller hub 11 allow dirt to be drained from the area of the bearing back to the pump inlet. Three bosses 23 for mounting the pump also provide attachment means for the fasteners 26 of an inlet screen 27.