Abstract: A cryogenic refrigerator comprises a compressor including a compressor housing within which a cylinder is mounted, and a piston reciprocal within the cylinder, and a cold finger including a low temperature cylinder within which a displacer is reciprocable, and a regenerater mounted within the displacer. A plurality of flat piston suspension springs include a plurality of spiral slits to provide a plurality of spiral arms deflectable as the piston is reciprocated within the compressor cylinder. A plurality of annular inner retainers are secured to the piston and adapted to sandwich the inner peripheral edges of the piston suspension springs. A plurality of annular outer retainers are secured to the compressor housing and include a plurality of projections extending inwardly from the outer ends of the spiral slits to sandwich the outer peripheral edges of the flat piston suspension springs.

Abstract: A refrigerator comprising a first cylinder and a second cylinder which are coaxially arranged, a first movable coil and a second movable coil which are oppositely arranged in a magnetic flux produced by a magnet, and which can be reciprocated by applying an a.c.

Abstract: A refrigerator comprises a compressor including a first cylinder having an inner cylindrical surface, a piston reciprocating in the first cylinder, and a linear motor for having a.c. electric input power applied thereto to drive the piston; a cold finger including a second cylinder having an elongated inner cylindrical surface, a displacer reciprocating in the second cylinder, and a cold space and a hot space which are divided by the displacer; a temperature detector for detecting the temperature in the cold space; an electric input power decision unit for having a detection signal inputted from the temperature detector and for deciding the electric input power to be applied to the linear motor so that the electric input power grows greater and greater as the temperature in the cold space decreases; and a power source for providing the electric input power to the linear motor based on the output from the electric input power decision unit.