| 摘要 |
PURPOSE:To prevent defective lubrication of respective compressors, a loss of lubricating oil and contamination of refrigerant, by connecting spaces on the gas sides of lubricating oil chambers with an inlet side of a compressor with the minimum inlet pressure for minimizing the amount of lubricating oil solved into the refrigerant. CONSTITUTION:The entire device comprises respective compressors 8, 9 for low pressure and high pressure, respective motors 10, 11 and respective oil chambers 12, 13 for accommodating speed increasing gears 14, 15 serving also as an speed increasing chamber. In this case, spaces on the gas side of the respective oil chambers 12, 13 are connected by communicating pipes 20, 21 having switching valves 22, 23 disposed at the side of an inlet port 16 of the low pressure compressor 8. Further, the respective oil chamber 12, 13 have liquid sides connected by a communicating passage 24 provided with a switching valve 25. With such an arrangement, the oil chambers in the compressors have a pressure identical with the lowest pressure in a system, the minimum amount of refrigerant is solved into lubricating oil and the refrigerant already solved can be removed, whereby defective lubrication, a loss of the lubricating oil and contamination of the refrigerant can be prevented.
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