Patent ID: 7225859

Claim:
The heat exchanger element for a Stirling cycle refrigerator, comprising: an annular corrugate fin produced by forming a sheet material, corrugated so as to have a large number of grooves, into a cylindrical shape with the grooves parallel to an axis of the cylindrical shape; and an inner ring-shaped member placed in contact with an inner periphery of the annular corrugate fin, wherein the annular corrugate fin is integrally attached to the inner ring-shaped member; wherein the annular corrugate fin is formed such that an external diameter of the annular corrugate fin is slightly larger than an internal diameter of the tubular body prior to insertion of the corrugate fin into the tubular body, and wherein at least one end of the tubular body is tapered so that the internal diameter of the body becomes greater toward that end along the axis, a maximum internal diameter of the taper is greater than the external diameter of the annular corrugate fin, and the annular corrugate fin is inserted into the taper axially from an end thereof.