GB1074029A - - Google Patents

Abstract

1,074,029. Rotary pumps, motors and meters. TRW, Inc. Dec. 9, 1965 [Sept. 3, 1965], No. 52314/65 Heading F1F. A rotary pump, (or meter) of the internalexternal gear type, comprises a body 10, Fig. 1, having a shaft 11 rotatably supported therein connected by a wobble shaft 21, to drive (or be driven by) a rotor 13, Fig. 2, which has external teeth 23 and rotates about its axis 26 in one direction and orbits about the axis 28 of a ring 12 held stationary between a wear-plate 14 and a cover 15, in the opposite direction. The ring 12 is formed with a plurality of recesses 51, one more in number than the number of teeth 23, loosely mounting rollers 50 which co-operate with the teeth to form variable volume pockets A ..... G. A sleeve-valve 20 driven by the shaft 11 by means of a recess 34 and pin 33 is formed with circumferentially-spaced radial passages 47 and axially-extending grooves 49 which cooperate with passages 40, 41 in the housing and a plurality of ports 43 in the wear-plate to supply and discharge hydraulic fluid to and from the pockets. As the rotor rotates and orbits the pressure difference in adjacent pockets urges the rollers 50 into sealing contact with the gear teeth and the recesses and prevents any noise that would otherwise occur due to "chatter". The differential pressure acting on the rollers allows any wear to be taken up without impairing sealing. The rollers are preferably provided with hardened surfaces to resist wear whilst the ring 12 may be made of less-hardened, easy-machined, high strength metal. In a modified embodiment, the recesses 51 in the ring 12 are rectangular in cross-section with the rollers 50 replaced by members having complementary-shaped surfaces loosely fitting the recesses and a rounded surface co-operable with the teeth 23.