Cryogenic refrigerator

Abstract

A cryogenic refrigerator according to an embodiment of the present invention is used in cooling a superconducting magnet. The cryogenic refrigerator includes a crankpin bearing of a scotch yoke. The crankpin bearing is made of a cylindrical nonmagnetic resin material. The crankpin bearing includes a cylindrical inner wall and a cylindrical outer wall. The cylindrical inner wall supports a crankpin. The crankpin is eccentrically attached to an output shaft of a motor slidably in a circumferential direction. The cylindrical outer wall contacts with an inner wall of a window portion of the scotch yoke. The cylindrical inner wall is made of another nonmagnetic resin material different from the nonmagnetic resin material of the cylindrical outer wall. Hardness of the cylindrical inner wall is higher than hardness of the cylindrical outer wall.

Dependencies are inferred from the claim text.