MULTISTAGE COMPRESSION DEVICE

PROBLEM TO BE SOLVED : To solve a problem of a conventional multistage compression device that, since a temperature of an electric element rises, winding resistance increases and it is difficult to use a rare earth magnet because of the temperature rise, so that efficiency may be lowered. SOLUTION : In a high-pressure shell type multistage compression device constituted by connecting a plurality of compression mechanisms in series, in at least an electric element driving an uppermost stage side compression mechanism out of the plurality of compression mechanisms, a stator is a split core concentrated winding motor as a concentrated winding type stator in which a coil is wound around a split core in a concentrated manner, or in at least an electric element for driving a lowermost stage side compression mechanism, a rotor is a brushless DC motor using the rare earth magnet, or at least in electric element driving an uppermost stage side compression mechanism, a rotor is a brushless DC motor using a ferrite magnet.