GB447318A - Improvements in and relating to refrigerating machines - Google Patents

Abstract

447,318. Rotary compressors. BRITISH THOMSON - HOUSTON CO., Ltd., Crown House, Aldwych, London. June 14, 1935, No. 8243/36. Convention date, June 14, 1934. Divided out of 447,859, [Group XIII]. [Class 110 (ii)] In a refrigerating-plant, a compressor has outwardly-sliding vanes which do not take up a loading position until oil under pressure from a second pump seals each end of the pump rotor and also forces out the vanes to make contact with the working chamber bore. The compressor is contained in a block 43 and is driven by an electric motor 37 by a shaft 38, which also drives an oil pump 58 which delivers oil from a sump 30 to counter-bores 66, 67, and to slots 53a behind the vanes 53, for sealing, lubricating, and vane-ejecting means. A spring 61 presses the diametral vane 59 of the oil pump, against a plate 47. The oil passes through a strainer 63 to an inlet 62, and is delivered through conduits 64, 65, to the compressor. The compressor rotor has vanes 53 which force refrigerant from an intake 56 provided with a strainer 57, to a delivery pipe 18 by way of a valve 54. The refrigerant re-enters the casing 15 through a pipe 29. Members forming casings for motor and compressor may be welded together as at 41, 44, 46. The leading edges of the blades 53 are rounded 53b in order that compressed gas in the working chamber will provide a small radial component of force tending to move the vanes inwards. The trailing edges of the vanes are relieved to reduce friction. To provide a substantialy constant pressure in the oil passages, the oil is delivered to a chamber 69 and forced through a sharp-edged orifice 68 in a vessel 72. Refrigerant vapour collecting in the latter vessel will form a cushion to damp out pulsations in the oil flow. The oil passes down a pipe 31 to be cooled, and re-enters the casing through a pipe 73 into a depression 74 from whence it flows over a hood 75, and past a baffle 42, which it cools, and falls to the sump 30. The space below the shell 75 is filled with refrigerant vapour which is circulated by a fan 37a for cooling purposes.