To obviate any noise being produced by a rotor effectively upon keeping up a pressure differential between both upper and lower basins of a motor, to the minimum by forming plural pieces of passages, where refrigerant gas flows in the axial direction of a shaft, on an outer surface of this shaft.
A shaft 21 is set up in keeping the same concentricity as a rotor core 11 of a motor 9. Plural pieces of third passes 22 for coolant gas use along the axial direction are formed on an outer surface of this shaft 21. This high temperature-high pressure refrigerant gas flow into the upper resin of a motor 9 by way of both first and second passages 12 and 13 from the lower basin of this motor 9, while it flows into the upper basin by way of the third passages 22 for refrigerant gas use. In addition to the passages hetetofore in use, a desired passage area is securable, and also a pressure differential between both these upper and lower basins of the motor is able to keep smaller than even before. Thus, any possible noise being produced by what a rotor is forcibly pressed upward, is effectively preventable.
HAGIWARA MAYUMI
MIYATA MAYUMI
