GB683678A - Improvements in or relating to gear pumps - Google Patents

Abstract

683,678. Rotary pump. BORG-WARNER CORPORATION. June 1, 1951 [June 16, 1950], No. 13050/51. Class 110(ii) In a gear pump having fluid-pressed bushes at one end, for sealing purposes, radial packing pieces are provided to divide up the external. surfaces of the bushes, the areas between such pieces being subjected to different pressures. In general the area opposite the delivery area within the pump, is subjected to fluid at delivery pressure. The packing pieces may be of metal, plastic material, rubber or neoprene. Fig. 2 shows bushes 32, 33 in which fluid under delivery pressure from the pump outlet 35 passes through a duct 36 to act on segmental surfaces 32a, 33a. Three sealing pieces 40, 41, 42 of U-shaped cross-section restrict the pressure areas with the open or lip portions facing towards the right. Semi-circular plates 43, 44, which are slightly thinner than the packing pieces, prevent lateral. movement of the pieces. The latter may be placed off the vertical axis passing through the gear centres. Fluid leaking past the pieces may be vented to the suction side of the pump through a duct 45. A modification, Fig. 5, uses radial pins 51, 54 provided in V-shaped or otherwise shaped grooves 53 of the pressure-loaded bushes 32, 33, the plates 43, 44 being dispensed with. Fig. 7 shows the use of blade-type seals involving a modification of the housing bore. Blades 61, 62, of rectangular cross-section, are supported by two pairs of half rings 63, 64, which act similarly to the plates 43, 44 in Fig. 2, but prevent lateral movement of the blades in either direction, the pump being reversible. Pair of semi-circular. washer-type springs 65, 66 are provided with each pair of half rings and also load the blades to give initial axial pressure against the bushes and thus against the side of the gears. Fig. 9 shows another modification in which bushes 71, 72 contain packing blades pressed upon initially by springs 84. Bushes 74 contain sealing rings and are pressed laterally by spring 75. Further modifications include spring-pressed circular pistons acting as seals or unitary seals of rubber or the like comprising bushes, Fig. 15 (not shown) having integral, radial sealing blades. The bush areas under different pressures may be greater than two, i.e. there may be three or more segmental areas on each bush. Various cross-sections of packing pieces are illustrated in Fig. 21 (not shown).