GB1406633A - Rotary pumps and compressors - Google Patents

Abstract

1406633 Rotary positive-displacement fluid-machines COPELAND CORP 26 Oct 1972 [29 Oct 1971 18 Oct 1972] 49373/72 Heading F1F In a pump or compressor comprising a planetary rotor the latter is cooled by the working fluid e.g. a refrigerant, flowing through the interior thereof before entering spaces wherein it is compressed externally of the rotor. One embodiment comprises identical hollow rotors 71, 72, 73 separated by fixed hollow plates 50, 51, co-operating with epitrochoidal surfaces 120 of fixed bodies 55, 56, 57 and revolving on eccentrics 75, 76, 77 secured to a shaft 26, the latter being furnished with balance weights 152, 153 and driven by an electric motor 24, 25 that is cooled by the working fluid as it flows to inlet ports 90, 91, 129. The fluid issuing from the ports 90, 91 enters compression spaces 110, 111, 112 circumjacent the rotor 71 through the interior of said rotor and ports 100, 101, 102 controlled by reed-type check-valves, outlet ports 113, 114 being controlled by valvemembers 115. The remainder of the incoming fluid enters the space circumjacent the rotors 72, 73 by way of the ports 129, passages 139, 140, chambers 170 in the plates 50, 51, ports 132, 133, 134 in each of said plates, and the interiors of said rotors, each of the ports 132 being controlled by a valve-member 126 that can be moved to a closed position (so as to unload the respective rotor) by fluid-pressure against the action of a compression spring 128. Fluid-pressure is applied to the member 126 from outlet passages 121, 122, 123 when a solenoid-operated valve-ball 148 is removed from an orifice 143. Gears 78, 80 to regulate the planetary motion of the rotor 71 are said to act as a pump, which feeds lubricating oil from a sump 23 to bearings 42, 44, 46, 48 by way of a passage 160, leakage oil being returned to the sump through a passage 155, a hole 162 in a retainer 34 for a screen 33 through which the incoming fluid passes from an inlet port 32, and an anti-foaming valve 164. In another embodiment, Figs. 11 to 15 (not shown), the ports 100, 101, 102 are dispensed with and transfer ports (165, 166) are provided in the fixed plates separating the rotors. In a further embodiment, Fig. 17 (not shown), each of said plates is furnished with two unloading valves located in diametrically-opposite positions and capable of being closed independently of each other so as to vary the output of the corresponding rotor.