Micro-expanded thermal switch

Abstract

The invention discloses a micro-expanded thermal switch, which comprises a heat conducting ring, a cold platform, an inner cylinder body, an outer cylinder body and connecting screws; the heat conducting ring is flexibly connected with a cold finger of a refrigerator; and the cold platform is rigidly connected with a detector support. When the refrigerator works, cold air is transmitted to the outer cylinder body, the inner cylinder body and the cold platform through the heat conducting ring, so that the outer cylinder body drives the heat conducting ring to move downwards to realize the turn-on of the thermal switch; and conversely, the thermal switch is turned off. The micro-expanded thermal switch has the advantages that: the outer cylinder body plays a role in realizing the displacement when the thermal switch is turned on, and plays a role in increasing turn-off thermal resistance when the thermal switch is turned off; the heat conducting ring is directly connected with the cold finger of the refrigerator, the heat transfer path is short, and the turn-on thermal resistance is small and is only the contact thermal resistance between Cu and Cu; and the micro-expanded thermal switch has simple and compact structure, light weight, small volume, and high reliability, can reduce the working pressure of the refrigerator, and decreases total thermal leakage of a backup system.

Description

technical field [0001] The invention relates to space mechanical refrigeration technology, in particular to a micro-expansion thermal switch, which is used in backup technology in space mechanical refrigeration systems. Background technique [0002] The rapid development of space infrared detection technology requires the refrigeration system to provide lower temperature and higher cooling capacity, so mechanical refrigeration technology has been widely used. However, there are moving parts in the mechanical refrigerator, which limits its service life. Due to the unmaintainability of the space refrigerator, in order to improve the reliability and life of the refrigeration system, it is necessary to use two or more refrigerators in the same system, one of which is It is in working condition, while the rest are in standby condition; when one of them fails or reaches the end of life, the other refrigerator starts to work. [0003] Multiple refrigerating machines are directly c...

AI Technical Summary

Problems solved by technology

See Chinese patent: 02150896.8, because its structure requires strict symmetry, so the processing precision is very high, otherwise it will cause the switch to fail to meet the performance requirements, and at the same time, the instability of the performance of the memory alloy makes the reliability of this type of thermal switch lower.

[0007] The two-way displacement type thermal switch uses thermal expansion and contraction of materials to realize the performance of the switch. See Chinese patent: 200710047625.3. Since the structure is designed as two sets of supports and contractions, the mechanical stability of the structure is complex and the reliability is low. , the weight is heavy, and the requirements for machining precision and assembly precision are high

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