GB366604A - Improvements in rotary compressors, exhausters and pumps - Google Patents

Abstract

366,604. Rotary compressors. SANDERS, J. M., Shannon Court, Corn Street, Bristol, and TAIT, J. D., 25, Victoria Street, London. Aug. 11, 1930, Nos. 24038/30 and 9557/31. [Class 110 (ii).] A rotary compresser or exhauster comprises a multithreaded worm or spiral gear 1 and a toothed ring 4 with their axes inclined to one another, the two members fitting a casing 2, 6, and rotating in mesh so that the teeth of the ring act as pistons in the grooves of the spiral gear, to compress the fluid contained therein. The two rotors closely fit the portions of the casings 2, 6, and an oil or glycerine seal is also provided. The top casing 2 has a spigot 8 which locates the.position of the toothed ring 4, and the lower casing 6 has its walls extended upwards at 11 into the ring chamber 5, the wall on one side being cut away to provide an opening in which the teeth of the rotors mesh. Oil is fed to the space 12 from a pipe 15 and drained off through an outlet 18. The oil is carried round by the teeth to seal the spaces between the rotors, and the casing walls, and also acts as a lubricant through channels 16 and gutters 17. A groove 20 drains off oil squeezed from between meshing teeth. Air to be compressed is admitted under the ring 4 through an inlet 13 and delivered through a port situated above the ring. A packing ring 9 is provided. Plain or ball bearings may be used. The compressed air may be delivered to an oil separator. In another arrangement the axes of the ring and spiral gear are inclined to one another at an angle less than 90‹. In this case a larger driving shaft 3 can be used. Fig. 8 illustrates a further arrangement. A casing 21 contains an oil bath through which moves the toothed ring 4, which is vertical but inclined at 30‹ to the axis of the rotor. The rotor casing 22 has projecting members 25 which form bearings for a portion of the ring 4. Inlet and outlet ports 13, 14 are provided. In modified constructions, two or more rings co-operate with one spiral gear, and a corresponding number of inlet and outlet ports are provided. The latter arrangement may constitute a multi-stage compressor. A further arrangement describes a toothed ring which is cup-shaped with long teeth formed on its inner curved surface, and is thick enough to envelop about a quarter of the circumference of the gear 1. All compressors are reversible. Provisional Specification 9557 of 1931 states that the ring may have outer teeth which are driven by an external gear.