GB637942A - Improvements in rotary compressors of the gear wheel type - Google Patents

Abstract

637,942. Rotary compressors. MARBLE, J. C. Feb. 26, 1948, No. 5755. Convention date, May 31, 1941. [Class 110(ii)] A meshing-screw compressor has cooperating rotors with male and female threads, clearances being provided between the rotor and the casing, the inlet ports such as 56, 58 directing the incoming fluid along an opening groove at high velocity, the fluid column striking an end wall 62, 64 with a ramming effect which produces a counter-wave in the fluid back towards the inlets. The peripheral extent of an inlet port 56, a, b,...f, a, Fig. 3 allows mainly axial fluid admission through the curved inlet, Fig. 1, and has a small portion of the inlet extending inwardly from an end wall. The outlet port 66 extends inwards to a line j, k, l...p, q on the edge of a partition 60 which provides the end wall surfaces 62, 64. Details of the axial and radial shapes of the port 66 and the action of the two rotors in co-acting with the port edges, are given in the Specification. The compressor casing may be single-ended. The male rotor 38 runs on bearings 16, 18 being driven by a shaft 50 through a key 48, a gear 44 driving a gear on the second shaft upon which the female rotor is mounted. Cooling fluid flows through a jacket 12 and is supplied to the interior of the rotors through hollow shafts 20 by way of Venturi tubes 26. Outlets 22 are provided in the shaft 20. The fluid leaves through an annular space 30 leading to a chamber 32 and an external cooler. Other kinds of cooling means may be used. The pitch circles lie on the root circle of the male rotor and on the periphery of the female rotor.