GB1206464A - Improvements in rotary positive-displacement pumps and motors - Google Patents

Abstract

1,206,464. Rotary positive-displacement pumps and motors. J. THOMSON. May 9, 1968 [Feb.10, 1967], No.6621/67. Heading F1F. A rotary positive-displacement pump, or motor, includes an annular chamber 16, Figs.1 and 2, defined by a rotor 12 and a stator 14 attached to a housing 52, the rotor being furnished with two pairs of radial vanes 26 with notches, or cut-outs, 27 therein to allow passage of a fixed abutment 18, which is provided with inlet and outlet ports 20, 22 for the working fluid. To effect radial reciprocation of the vanes in synchronizm with the rotary motion of the rotor, the vanes that are diametrically opposed to each other are coupled together by a member 25, which engages with a respective cam 38 attached to a rotatable shaft 40, that latter being eccentric relative to the rotor and a driving shaft 56 therefor. The abutment is fixed to the stator so that during operation of the pump or motor it virtually travels in a circumferential direction through the chamber 16 and co-operates with the vanes to effect a pumping action or rotation of the rotor. To relieve pressure in the notch 27 of the vane adjacent the abutment, a slot (51), Fig. 3 (not shown), may be formed at either end of the abutment. In a modification, Fig.7 (not shown), the notch in each of the vanes is situated radially beyond the annular chamber whenever the respective vane is diametrically opposite the abutment. In another modification, Fig. 9, the notches aforesaid are omitted, the vanes being such that they lie wholly within the portion of the rotor that is radially inward of the chamber 16 when they are adjacent the abutment. Mutually adjacent slots 108 into which the vanes project when they are remote from the abutment are connected to each other by ducts 50 to prevent fluid being trapped therein. Axial balancing of pressures in the chamber 16 is effected by arcuate recesses (60), Fig. 8 (not shown), in the rotor adjacent the housing 52 being connected to said chamber by axial conduits (62) in the rotor. Leakage fluid in a cavity 72 escapes through an outlet 72 to which a further cavity (74) in the housing circumjacent the shaft 56 and a chamber 24, Fig.2, are also connected to effect removal of leakage fluid therefrom. The recesses (60) and the arrangements for escape of leakage fluid may be included in the pump or motor according to Figs.1 and 2.