Magnetic refrigeration device and liquefaction device using low-temperature pump

A magnetic refrigeration device adapted to cool an object to be cooled, comprising:

• a cryostat with an inside evacuated to be heat insulative;
• a cryogenic pump installed inside the cryostat to circulate a heat exchange gas;
• a magnetic refrigerator installed inside the cryostat to cool using a magnetic working substance having a magnetocaloric effect;
• a drive mechanism including a drive shaft to feed the heat exchange gas from the cryogenic pump to the magnetic refrigerator and to feed back the heat exchange gas to the cryogenic pump;
• and
• a thermal anchor provided between the cryogenic pump and the magnetic refrigerator to cool the heat exchange gas,
• wherein
• the cryogenic pump has an upper bellows and a lower bellows facing each other via a partitioning plate,
• at least a part of an inner side of each of the upper bellows and the lower bellows is opened to a vacuum chamber side of the cryostat, and
• with the heat exchange gas, under pressure, contained in an upper bellows chamber and a lower bellows chamber that are respectively formed on outer sides of the upper bellows and the lower bellows, the upper bellows and the lower bellows are alternately expanded and contracted so that the heat exchange gas in one of the upper bellows chamber and the lower bellows chamber is pushed out to a magnetic refrigerator side by the drive shaft, and the heat exchange gas in another of the upper bellows chamber and the lower bellows chamber is sucked from the magnetic refrigerator side by the drive shaft.