Rotary-type fluid machine and refrigeration cycle apparatus

A rotary-type fluid machine comprising:

• a closed casing having a bottom portion defining an oil reservoir;
• a rotary-type fluid mechanism provided in an upper portion of the closed casing, the rotary-type fluid mechanism having a cylinder forming a working chamber and a partitioning member, the working chamber partitioned into a suction side working chamber and a discharge side working chamber by the partitioning member;
• a shaft having therein an oil supply passage for supplying oil to the fluid mechanism, the shaft connected to the fluid mechanism and extending to the oil reservoir;
• an oil pump provided at a lower portion of the shaft;
• and
• an oil retaining portion for retaining oil, supplied by the oil pump through the oil supply passage, in a surrounding region around the fluid mechanism to allow the partitioning member of the fluid mechanism to be lubricated, the oil retaining portion formed so that a liquid level of the oil retained therein is positioned higher than a lower face of the partitioning member, wherein:
• the oil retaining portion is formed by (i) an inner circumference surface of the closed casing, (ii) a support for supporting the fluid mechanism, the support being fixed to the closed casing, and (iii) an overflow pipe for allowing excessive oil to flow down to a region below the support when the liquid level of the oil retained in the surrounding region around the fluid mechanism exceeds a predetermined height, the overflow pipe being attached to the support;
• the overflow pipe has an upper opening that is at a position higher than the lower face of the partitioning member;
• the predetermined height corresponds to the height of the upper opening,
• the oil retaining portion is located lower than the upper opening of the overflow pipe;
• the fluid mechanism comprises an upper bearing member fixed to an upper portion of the cylinder so as to support the shaft rotatably;
• the oil supply passage is open at an upper end face of the shaft;
• the shaft vertically penetrates the upper bearing member, so that the oil supply passage directly communicates with an upper space, which is defined by the inner circumference surface of the closed casing, around the fluid mechanism;
• and
• the upper space is a space to which the overflow pipe opens.