Compressor motors for turbo refrigerators

Abstract

The present invention provides a motor for a compressor of a turbo refrigerating machine, which can prevent liquid refrigerant from leaking from a portion of a labyrinth seal that seals a shaft of a rotating shaft of a motor that drives a turbo compressor to a housing having an oil storage portion. Decrease in oil viscosity due to decrease in oil temperature and prevent reduction in efficiency of refrigerators. In the turbo refrigerator, the motor (11) driving the turbo compressor (1) is provided with a labyrinth seal member (20) having a Facing the labyrinth seal composed of tooth rows for shaft sealing, the labyrinth seal member (20) is located closer to the axial center of the rotating shaft (12) than the labyrinth seal composed of tooth rows. The position includes an extension part (21e) having a substantially truncated conical inner peripheral surface expanding toward the central part side of the rotation shaft (12).

Description

technical field [0001] The present invention relates to a motor for a compressor of a turbo refrigerator, and more particularly, to a motor for a compressor in which a part of refrigerant is guided from a refrigeration cycle to an electric motor driving a turbo compressor in a turbo refrigerator to cool the motor. Background technique [0002] Conventionally, turbo refrigerators used in refrigerating and air-conditioning equipment and the like are constituted by a closed system in which a refrigerant is sealed, and are configured as an evaporator that absorbs heat from cold water (fluid to be cooled) to evaporate the refrigerant to exert a cooling effect, A compressor that compresses the refrigerant gas evaporated by the evaporator to become a high-pressure refrigerant gas, a condenser that cools the high-pressure refrigerant gas with cooling water (cooling fluid) to condense it, and The expansion valve (expansion mechanism) that depressurizes the refrigerant and expands it ...

AI Technical Summary

Problems solved by technology

The gear case 18 having the oil storage part 19 communicates with the motor case 17 through the through hole through which the rotating shaft 12 passes, so there is a problem that the oil leaks into the refrigerant system and lowers the oil level of the oil storage part 19, thereby damaging the supply. Oil function, or refrigerant leakage into the oil system lowers the temperature of the oil, making it impossible to ensure the specified oil viscosity, and refrigerant gas that does not contribute to the refrigeration capacity flows from the high-pressure part of the refrigeration cycle to the low-pressure part, causing the efficiency of the refrigerator to drop

[0014] Nevertheless, since a large amount of liquid refrigerant in the motor leaks into the gear case 18 having the oil storage portion 19 through the labyrinth seal LS, as described above, the viscosity of the oil decreases and the efficiency of the refrigerator decreases. A structure in which liquid refrigerant does not stay near the teeth of the labyrinth seal LS as much as possible

Images