GB680922A - Improvements relating to compressor units for refrigerating apparatus - Google Patents

Abstract

680,922. Refrigerating. GARDINER, L. A. J. Feb. 8, 1951 [Jan. 4, 1950], No. 204/50. Class 29 [Also in Groups XXVIII and XXXV] A motor-compressor unit for refrigerating apparatus comprises a casing 1 carrying the stator 4 of the electric motor, a separate compressor housing 8 in the form of a casting having the cylinder or cylinders 27 of a reciprocating compressor formed in it, and an intermediate bearing structure 14 for a shaft 19 which carries at opposite ends the rotor 17 of the motor and the driving element 45 of the compressor, the casing 1 and housing 8 being releasably connected by screws 12 to form a fluid-tight closure. The intermediate structure comprises a bearing 13 with six spider arms 14 which rest upon webs 15 formed inside the housing 8 and are secured by studs 16. The casing 1 has heat dissipating vanes 7 and carries the motor terminals 5. The small clearance 21 between the rotor 17 and stator causes oil to be thrown down from the vapour-oil mist rising between the spider arms 14, the vapour passing back to the compressor through a connection 24 provided with a filter 25. An eccentric sheave 46 secured on a threaded part 47 of the shaft 19 drives a piston 43 in the cylinder 27 bored in a thickened part 26 of the housing 8. A valve cover 30 secured to the housing encloses the suction and delivery valves 34', 34<SP>2</SP> and service valves. A spiral groove 52' in the lowermost part of the shaft 19 acts as a pump to force oil down into a cup 53 and thence through an axial bore 19' and cross bores to the spider bearing 13, the eccentric and the small end bearing. A multicylinder compressor is also described in which seven cylinders are spaced around the housing 8, one piston rod being integral with the eccentric strap and the other rods connected thereto by pivots, the valve chambers for the cylinders being coupled by ring pipes.