GB1296775A - - Google Patents

Abstract

1296775 Rotary pumps and motors ABEX CORP 10 April 1970 [21 April 1969] 17249/70 Heading F1F In a multiple abutment sliding vane pump or motor in which each vane 29, Fig. 2, is formed with grooves 54 in its radial outer surface 70 and opposite side surfaces 71 so that each vane is in hydraulic balance. Each vane is acted upon by a piston 59 subjected on its inner face to the pressure within an internal annular pressure chamber 57 which communicates with the high-pressure side of the pump or motor to urge the vanes radially outwards into sealing engagement with the cam surface 30 of the cam ring 20. A spring-loaded non- return valve 65, Fig. 1, is inserted between the said chamber and the high-pressure side of the pump or motor and opens only when the pressure on the high-pressure side of the pump or motor exceeds that in the said chamber. Instead of the chamber 57 being formed in a resiliant member 58 of, e.g., neoprene disposed between a splined shaft 15 and rotor 25 (as shown) the shaft and rotor may be of unitary construction and the chamber formed in the rotor. A check plate 27 is subjected on its rear face to pressure at the high-pressure side of the pump or motor to seal the axial end faces of the rotor.