GB785092A - Rotary compressor - Google Patents

Abstract

785,092. Centrifugal compressors. YORK SHIPLEY, Ltd. Oct. 11, 1955 [May 23, 1955], No. 28950/55. Class 110 (1). [Also in Group XXXIV] A centrifugal compressor comprises a shaft 66 which drives a compressor impeller 65 and a centrifugal oil pump impeller 69, the shaft being mounted in bearings in a housing 14 provided with a reservoir 37 for lubricant separated by a partition 35 from a sump 36. The impeller 69 discharges lubricant to chamber 88 from which it flows through passage 108 and pipe 109, to a filter, then through pipe 112 and passage 113, part of the lubricant flowing to a bearing 68 and part through part 57 and channel 56 to a bearing 46. Some oil from bearing 68 returns to the pump and some flows by passage 114 and valve 115 to the reservoir 37. When there is considerable pressure of oil at the bearing 46 a spring-pressed seal ring 74 is moved back allowing oil to enter space 58 and flow by way of port 59 to sump 36. Oil is delivered from sump 36 to chamber 37 through pipe 116 under pressure caused by compressed vapour which flows between the shroud plate of impeller 65 and plate 51, past a seal 79 and through space 58 and passage 59 to the sump 36. Some of the oil in channel 56 flows past a thrust bearing 44 to a space 91 and through nozzle 117 to line 118 entraining oil from the chamber 37. The oil from line 118 passes through a cooler before returning by pipe 121 and passage 122 to the pump inlet. The impeller shaft 66 has the thrust bearing 44 engaged by an elastic disc 48 which carries the bearing 46. An enlarged portion 71 of the shaft 66 is formed with two diametrically-opposite ratchet notches 92 for engagement by a pawl 93 which prevents reverse rotation when the compressor is shut down and when the compressor is in action, acts as a valve and closes port 96. It also prevents rotation of shaft 66 when drive-shaft 98 is being unscrewed to disassemble the compressor. A unit 123 interposed between pump discharge 88 and chamber 37 comprises a ball valve 124 which may close against an upper seat 126 and is sustained by a slotted bushing 125. It passes air bubbles when new oil is being used but soon closes to prevent a free path for oil flow. In a refrigerant compressor, any refrigerant dissolved in the oil is boiled off through a spring-loaded relief valve 64 with a restricted port, the valve being connected by a pipe 62 to the inlet throat 23 of the compressor.