Abstract: A hermetic motor compressor comprises a casing which includes a dome-like upper casing and a dome-like lower casing. Each of the upper and lower casings has an engagement portion for telescopically engaging with each other. The stiffness of the upper casing is increased by making at least three corner portions close to the engagement portion. Crescent-shaped portions, curved surfaces, an apex portion and crest lines are also provided for the upper casing. This specific structure of the upper casing may be made also for the lower casing, and when both of the upper and lower casings have such construction, the corner portions of the upper casing and the corner portions of the lower casing are arranged alternatively so that the vibrating modes of respective casings offset each other. The shape of the entire casing may be spherical or ellipsoidal.

Abstract: A heat pump including an indoor heat exchanger, a main outdoor heat exchanger and an auxiliary outdoor heat exchanger provided underneath the main outdoor heat exchanger and connected between the indoor and main outdoor heat exchangers in a closed refrigerant flow circuit. The refrigerant flow circuit includes a compressor and a reversal valve which can be adjusted (1) during cooling operation to direct the hot compressed gaseous refrigerant from the compressor to the main outdoor heat exchanger and thence to the auxiliary heat exchanger acting as a sub-cooler into the indoor heat exchanger for extracting heat from air of the interior of a building and (2) during heating operation to direct the hot compressed gaseous refrigerant to the indoor heat exchanger to supply heat to the indoor air and then to the auxiliary heat exchanger now acting as a defroster for melting a block of ice which may have accumulated under the main outdoor heat exchanger and into the main outdoor heat exchanger.