A hermetic type compressor includes a compressor main body container that is a vertical type having a cylindrical shape, an accumulator container, a compression section that is arranged inside the compressor main body container, that compresses the refrigerant, sucked from the accumulator container, and that discharges the compressed refrigerant. The accumulator container includes an accumulator shell having a cup shape and a weld portion in which an opening side of the accumulator shell is bonded to the compressor main body container. A partition member, which partitions an interior portion of the accumulator shell, is provided in the interior portion, and a thermal insulation section, which blocks a heat transfer from the compressor main body container to the accumulator container, is formed between the partition member and a bottom shell, included in the compressor main body container. A thermal insulation member is provided in the thermal insulation section.

A rotor assembly and a compressor are provided. The rotor assembly has a crankshaft, a rotor core, a balance weight and an oil baffle shield. The rotor core is provided with a vent hole. The vent hole extends through the rotor core along an axial direction of the rotor core. The balance weight is located at one end of the rotor core approximate to an oil sump of the compressor. The oil baffle shield is arranged to cover the balance weight and is provided with a central opening. The crankshaft extends through the central opening. An accommodating space is defined between the oil baffle shield and the rotor core. The accommodating space is communicated with the vent hole.

A rotary compressor and a refrigeration cycle apparatus are provided that: can reliably reduce pressure pulsation and vibration in an intermediate pipe connecting a discharge side of a low-stage compression mechanism and a suction side of a high-stage compression mechanism; and can downsize the apparatus including a muffler. A rotary compressor includes: a first cylinder having a first compression chamber that compresses introduced low-pressure refrigerant gas to medium pressure and discharges the compressed refrigerant gas; a second cylinder having a second compression chamber that compresses introduced medium-pressure refrigerant gas; an upstream intermediate pipe guiding the medium-pressure refrigerant gas, discharged from the first compression chamber, to an outside of the sealed container; and an external muffler connected to the upstream intermediate pipe. Relationship between outlet area S1 of the upstream intermediate pipe and flow path cross-sectional area S2 of the external muffler is 0.01(S1S2)0.04.

A compressor unit includes a compressor body including a compression mechanism, and an accumulator connected to the compressor body. The compression mechanism includes a cylinder, a piston to rotate eccentrically in the cylinder, and a blade partitioning an interior of a compression chamber of the cylinder into low and high pressure chambers. A frequency one time an operation frequency n of the compressor body and a frequency three times the operation frequency n of the compressor body are a 1n frequency and a 3n frequency, respectively. A phase difference between a phase of a transfer function of the 1n frequency of the accumulator and a phase of a transfer function of the 3n frequency of the accumulator is 2060 with respect to a peak of the 1n frequency where the phase lag is positive, at a maximum number of revolutions of the compressor body.