Expander for stirling engines and cryogenic coolers

摘要

The invention is directed to an improved cryogenic cooler with an expander where the regenerator matrix is decoupled from the displacer or piston, thereby allowing the design of each to be optimized substantially independently. The regenerator matrix is preferably positioned spaced apart from the displacer and can be designed to enhance thermal exchanges and flow rates of the working gas. In one embodiment, the regenerator matrix has a serpentine shape or U-shape disposed around the displacer and the cold finger. Preferably, the regenerator matrix is static. The thermal lengths of the cold finger and/or the displacer can be extended by minimizing their geometrical lengths. Additionally, the structural integrity or stiffness of the cold finger and/or displacer can be strengthened.

主权项

1. An expander for a cooler comprising:
an outer cylinder; a displacer disposed in the outer cylinder and adapted for reciprocal motion relative to the outer cylinder; an expansion space adapted to expand a working fluid, wherein the expansion space is defined at a distal end of the expander between the outer cylinder and the displacer; a regenerator matrix disposed spaced apart from the displacer and static relative to the outer cylinder, wherein the regenerator matrix comprises a serpentine shape or a plurality of U-shape paths and a thermal effective length longer than a length of the outer cylinder along a direction of the reciprocal motion of the displacer; an end cap located at the distal end of the outer cylinder to conduct the working fluid from the regenerator matrix to the expansion space; and an infrared sensor of an infrared camera thermally coupled to the end cap, wherein the cooler cools the infrared sensor of the infrared camera.