GB1172579A - Pressure Loaded Hydraulic Gear Pumps or Motors - Google Patents

Abstract

1,172,579. Rotary positive-displacement pumps. BORG-WARNER CORP. July 19, 1967 [Aug. 15, 1966], No.33265/67. Heading F1F. A rotary positive-displacement hydraulic pump of the externally-meshing gear-wheel type comprises an axially-movable wear-plate 30, Fig. 2, between a pair of pumping-gears 13, 14 and an inner surface 31 of a housing or body furnished with an end cover 12, grooves 77, 78, Fig. 8, in the wear-plate being substantially filled by a resilient member 80 made of e. g. an elastomeric material, and a sealing member 81, which together with the surface 31 and the wear-plate forms two separate chambers to facilitate pressure-loading. Partially-conical projections (85, Fig. 10 not shown), formed on the member 80 abut the bottom of the groove 77 to hold the wear-plate in contact with the gears. Spaces between the member 80 and the walls of the grooves 77, 78 are charged with liquid from the high-pressure side of the pump through radial grooves 79 and a gap between the housing and an edge 65 of the wear-plate. so as press the member 81 against the surface 31 and projecting edges 66 of the wear-plate against the housing to minimize leakage of liquid from the high-pressure side of the pump to the low-pressure side. The aforementioned chambers are rendered in communication with the high-pressure and low-pressure sides, respectively, by recesses (51, 56, Fig. 6, not shown), in the housing adjacent edges 70, 71 of the wear-plate. Recesses (74, Fig.7, not shown), in the face of the wear-plate adjacent the gears permit lubrication of bearing bores 21 for journals 16 on the gears. Further recesses (45, 46, 48, 49, Fig. 5, not shown), in the wearplate and the end cover 12 communicate with the recesses (51, 56) to facilitate escape of liquid trapped between the meshing gear-teeth. Arcuate recesses (47, Fig. 4, not shown), distribute liquid to the gear-tooth spaces from the recess (45). In a modification of the wear-plate, Fig. 13, members that are similar to the members 80, 81 are lodged in a groove 77a, a sealing member 95 made of an elastomeric material being lodged in another groove 98 to minimize leakage of liquid from the bearing bores to the low-pressure side.