GB768664A - Improvements in or relating to multiple pumps - Google Patents

Abstract

768,664. Gear pumps; centrifugal pumps. THOMPSON PRODUCTS, Inc. Aug. 5, 1954, No. 2303/56. Divided out of 768,663. Classes 110 (1) and 110 (2). A multiple gear pump, Fig. 1, incorporates a centrifugal impeller 107 which pumps fluid from the inlet 106 to the pumping cavities 103, 104 and is driven at a speed higher than that of the gear pumps through a gear train 121, 126. Movable bushings 129 are loaded by fluid fed to chambers 134 and are provided with lubricant recesses 142, 143, 146, each passage 146 incorporating a valve comprising a restriction orifice controlled by a spring-loaded ball, see Fig. 4 (not shown). The lubricant return passages 162 in the bearing surfaces of the housing 101 are also provided with valves 148; for details of said passages, Fig. 3 (not shown) should be referred to. The discharge pressure may be bled across the members 129 to the inlet side of the pump by a groove 165, see Fig. 3 (not shown), a secondary groove 163 connected to a source of high pressure being also provided. The output of the pump is fed to a flow control unit 178 and hence to burners 179, a by-pass conduit 186 being provided between the chamber 102 and the chambers 103, 104. The centrifugal impeller is preferably designed to produce a discharge greater than the combined capacity of the gear pumps and in a modified arrangement, see Fig. 6, a proportioned amount of the discharge from the impeller is metered through restrictions 191, 192 in a passage 190, said restrictions communicating with the bearing surfaces as shown.