Patent ID: 6886348

Claim:
A Stirling refrigerator comprising: a casing ( 15 ); a cylinder ( 3 ) provided in said casing ( 15 ); a piston ( 1 ) provided in said cylinder ( 3 ) to be made movable in a reciprocating manner in the axial direction of said cylinder ( 3 ) by a linear motor ( 16 ) provided externally to said cylinder ( 3 ); and a displacer ( 2 ) provided in said cylinder ( 3 ) to form a compression space between itself and said piston ( 1 ) in said cylinder ( 3 ) and to be movable in a reciprocating manner in the axial direction, said linear motor ( 16 ) including an inner yoke ( 13 ) provided on an outer periphery of said cylinder ( 3 ), an outer yoke assembly ( 9 ) placed externally to said inner yoke ( 13 ) to face said inner yoke ( 13 ), and a permanent magnet ( 12 ) placed in a gap between said inner yoke ( 13 ) and said outer yoke assembly ( 9 ) and coupled to said piston ( 1 ), and said outer yoke assembly ( 9 ) including a bobbin/coil ( 9 a ) placed to face said inner yoke ( 13 ), an outer yoke ( 9 b ) provided to cover said bobbin/coil ( 9 a ) from said casing and in the axial direction, and a pair of ring-shaped holding members ( 10 a , 10 b ) provided to hold said outer yoke ( 9 b ) therebetween in the axial direction.