GB1177733A - Improvements in and relating to Hydraulic Rotary Motors or Pumps - Google Patents

Abstract

1,177,733. Rotary hydraulic pumps and motors. RELIANCE ELECTRIC & ENG. CO. April 22, 1968 [May 4, 1967], No. 18837/68. Heading F1F. A rotary hydraulic pump or motor, comprises a housing 12, Fig. 3, having fluid passages (26, 28, Fig. 7, not shown), one an inlet and the other an outlet, a stationary internally-toothed outer gerotor element 34, Fig. 4, an externally-toothed inner gerotor element 40 keyed to an input or output shaft 30, an externally and internally-toothed intermediate gerotor element 50 disposed between the outer and inner elements and in operative engagement therewith for relative orbital movement and forming expanding chambers and contracting chambers therebetween, with the number of external teeth on the inner and intermediate elements being less than the number of internal teeth on the intermediate and outer elements respectively, as shown one less, and valve porting means continually connecting the expanding chambers between the outer and intermediate elements to one of said fluid passages and the contracting chambers between these elements to the other of said fluid passages. Operating as a pump with the shaft 30 rotating counter-clockwise, the inner element 40 imparts an orbital movement to the intermediate element 50 to thereby expanding chambers 60 and contract chambers 62. As element 50 orbits a cam surface 76, Fig. 3, thereon by engagement with a cam surface 78 on a ported plate 70 rotates the latter which is freely mounted on the shaft to maintain an arcuate slot 82, Fig. 5, in synchronous relationship with the expanding chambers and an arcuate slot 90 in synchronous relationship with the contracting chambers. The slot 82 communicates with the inlet passage (26) through radial ports 84, annular passage 86 surrounding the plate 70 and an annular channel 72 in the housing part 14. The slot 90 communicates with the outlet passage (28) through an annular groove 93 and an annular channel 74 in the housing part 14. A port 95 extending through the plate 20 substantially hydraulically balances this member. The number of external teeth on the intermediate element is twice the number of teeth on the inner element. The cavities between the elements 40 and 50 are maintained at the same pressure through an annular space 96 in the intermediate element 50. A modified rotatable ported plate 109, Fig. 10, (not shown) includes further arcuate slots connected to the slots 82, 90 by passages respectively so that the cavities between the intermediate and inner elements may be utilized for pumping or augmenting the motor torque.