GB1071097A - Improvements in and relating to vane type pumps and motors - Google Patents

Abstract

1,071,097. Rotary pumps and motors. AMERICAN BRAKE SHOE CO. July 1, 1, 1964 [July 18, 1963], No. 27205/64. Heading F1F. A rotary pump, or motor, of the outwardlysliding vane type has inlet and outlet passages 24, 25 in a housing 20, 21 containing a cylindrical rotor 42 carrying a plurality of radial vanes 45 provided with pressure-balancing grooves 84, the radially-inner most surface 95 of each vane being in engagement with one end of a tubular valve-element 92, which is slidably lodged in a radial bore 88 extending between an annular passage 89 and an axial bore 86 at the base of a slot containing the vane, whereby each vane is pressed outwardly into contact with the inner peripheral surface 46 of a cam ring 32 by the pressure of working fluid within the passage 89. The profile of the surface 46 is substantially elliptical, Fig. 2 (not shown), the minor axis thereof being substantially equal to the diameter of the rotor so that two crescent shaped working spaces are formed. The extremities of each working space are in register with pairs of inlet and outlet ports (72, 73), Fig. 3 (not shown), and 76, 77, the ports 72, 77 being formed in a pressure loaded check-plate 43 whereas the others are formed in the housing port 21. The outlet ports 76, 77 communicate with additional outlet ports 78, which are in register with the bores 86, and the inlet ports (72, 73) communicate with additional inlet ports (74), Figs. 3, 4 and 5 (not shown), which are generally similar to the ports 78. The passage 24 is connected to the inlet ports by annular passages 37, 38 surrounding the ring 32. Pressure-loading chambers 68 for the plate 43 are connected to the outlet ports by axial bores 66 and transverse or radial passages 82. Pressure in the passage 89 is kept substantially constant and equal to that in the outlet ports by working fluid entering this passage through a radial bore 93 each valve-element 92 when the associated vane passes one of the outlet ports, the valveelement being depressed radially-inwardly when the pressure in the passage 89 is less than that in the outlet ports. In a modification, Figs. 6, 6A and 6B (not shown), passages (123) in the rotor between vane slots (110) are in register with a chamber (122) in the centre of each vane (119) and contain working fluid at a pressure kept substantially constant and equal to that in the outlet ports by a tubular valve-element (124) slidably lodged in each vane, the valve-element having a radial bore 125 therein and being deflected radially-outwards when the pressure in the working spaces exceeds that in the said passages. The radially-innermost end (126) of each valve-element normally engages with the surface (112) of a rectangular axial bore (111) at the base of the associated slot (110). A bore (115) extends obliquely between each bore (111) and the periphery (116) of the rotor without intersecting the adjacent passage (123). When pressure in each bore (115) exceeds that in the passages (123) the adjacent valve-member is deflected away from the associated surface (112) to allow fluid to enter the passages (123) through the bore (125). In another modification, Fig. 7 (not shown), each vane (141) is pressed against the cam ring by the pressure of working fluid in an annular passage (133) within the rotor acting on a valve-element (135) having grooves (136) therein for admitting the fluid to said passage from a space (137) beneath the vane, the pressure in said passage being kept substantially constant by radially inward deflection of each valve-element when the associated vane passes an outlet port and the pressure therein exceeds that in said passage. In a further modification, Fig. 8 (not shown), each vane (147) is pressed against the cam ring by compression springs (143) and the pressure of working fluid in a passage (157) associated with valve-elements (153), which are generally similar to the valve-elements 92 save that they are loosely attached to the vanes. Two or more valve-elements may be provided for each vane, and each valve-element may be kept in contact with the associated vane by a spring. The portion 21 of the housing and the check plate 43 can be placed in any one of four different angular positions relative to the portion 20 of the housing to effect forward or reverse operation of the pump or motor.