THERMODYNAMIC RECIPROCATING ENGINE

PURPOSE:To utilize an engine also as a compressor by providing a passage transfer section communicating or cutting off between a high-temperature side operation space and a low-temperature side operation space and also providing the intake and discharge mechanisms in either space. CONSTITUTION:A low-temperature side operation space 4 encircled by a displacer 1 and a cylinder head section 3 is communicated to a high-temperature side operation space 6 encircled by the displacer 1, a piston 2, and a cylinder wall section 5 through a low-temperature side communicating port 7, a reclaimer 8, and a high-temperature side communicating port 7. A passage transfer section 19 movable up and down with a bolt 20 is provided on the cylinder head section 3. When the engine is used as a refrigerator, the low-temperature side communicating port 7 and the low-temperature side operation space 4 are communicated. When it is used as a compressor, the passage transfer section 19 is lowered, then the low-temperature side operation space 4 is cut off from the low-temperature side communicating port 7 and is also communicated to an intake passage and a discharge passage through an intake valve and a discharge valve.