GB787162A - Improvements in or relating to gear pumps - Google Patents

Abstract

787,162. Gear pumps. NEW PRODUCTS CORPORATION. April 13,1956, No. 11364/56. Class 110 (2). A gear pump of the internally- or externallymeshing gear type, Fig. 3, is provided with a rubber or like elastic insert 24 adjacent its outlet Z which incorporates an apertured pressure regulator plunger 33 slidably mounted in a ported sleeve 30, a relief valve 39 being also disposed between the inlet and outlet sides of the pump as shown. The plunger controls the bypass of fluid to the inlet 16 of the pump through ports 31, 32. A seal 41 comprising a metal wear plate 42 having a rubber member 44 vulcanized thereto is positioned as shown and urged against the gears by pressure fluid introduced through a port 50 (see also Fig. 5, not shown). The insert 24 may have metal shoulder pieces bonded thereto (see Fig. 6, not shown). In a modification, Fig. 8, the pump incorporates a metal sealing plate 60, a resilient cushion 60<SP>1</SP>, a seal 69, 70 and a sealing block 61 having a passage 63 communicating with a spring-loaded plunger 66, 67. In a second modification, Figs. 9 and 10 (not shown), the gears bear against a resilient crescent-shaped block which is sustained by a metal plate. In a third modification, Fig. 11, a pair of metal sealing shoulders 90 are arranged adjacent the outlet zone Z as shown, each shoulder having a seal 103 and a cavity 101 which communicates with the zone Z through a passage 102. In a final modification, Fig. 13, a metal seal 104 is urged by adjustable spring means 111 against the gear teeth.