Cryogenic refrigerator

Abstract

The present invention provides a cryogenic refrigerator which is not influenced by complication of the structure and can restrain a motor against synchronized separation. The cryogenic refrigerator includes a compressor (1) that compresses a working gas; a displacer (3) to which the working gas compressed by the compressor is supplied; a dog link mechanism (22) that includes a drive shaft (33) and is configured to drive the displacer (3); a motor (15) that drives the dog link mechanism; a housing (23) that accommodates the dog link mechanism; and a valve mechanism (V1, V2) that adjusts a pressure of the working gas supplied to the displacer (3), wherein a supply pipe (1a) that supplies the working gas from the compressor (1) to the valve mechanism (V1) is provided with a branch pipe (40) that branches out from the supply pipe (1a), and the branch pipe (40) is connected to an auxiliary space formed between the drive shaft (33a) and the housing (23).

Description

technical field [0001] This application claims priority based on Japanese Patent Application No. 2013-008755 filed on January 21, 2013. The entire content of this application is incorporated in this specification by reference. [0002] The invention relates to an ultra-low temperature refrigerator which drives a displacer through a motor. Background technique [0003] A Gifford-McMahon (GM) refrigerator is known as a refrigerator that generates ultralow temperatures. The GM refrigerator is a refrigerator that uses the volume change of the space produced by the displacer that reciprocates in the cylinder using a drive mechanism, and obtains a cooling effect based on the Gifford-McMahon refrigeration cycle. [0004] Therefore, the high-pressure working gas generated by the compressor is supplied to the displacer using the valve mechanism at a predetermined timing. Furthermore, in order to improve cooling efficiency, a cold storage material is arranged inside the displacer. ...

AI Technical Summary

Problems solved by technology

[0009] However, this GM refrigerator has problems such as its complicated structure and the danger of refrigerant gas leakage in the gas flow path.

[0010] In addition, as the cooling capacity increases with respect to the capacity of the driving source, the driving torque may temporarily increase during the operation cycle.

This is caused by the pressure loss generated in the displacer, and there is a risk of out-of-synchronization (slippage) of the motor driving the scotch yoke due to the increased amount of drive torque

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