Patent ID: 10072608

Abstract:
The displacer 2d . . . has a gas retention space Hg . . . formed therein. The gas retention space Hg . . . enables a working gas G to be alternately moved between a heating unit 3h side and a cooling unit 3c side of a displacer cylinder 2c . . . by the movement of the displacer 2d . . . . The displacer 2d . . . and the displacer cylinder 2c . . . have an outer circumferential surface 2df and an inner circumferential surface 2ci, respectively, formed into such shapes as to be able to permit the movement of the displacer 2d . . . and inhibit passage of the working gas G. The displacer 2d . . . has a gas passageway 7 which is formed on its outer circumferential surface 2df and includes a gas passage groove that allows the gas retention space Hg to communicate with a working gas inlet/outlet 6 . . . provided in the displacer cylinder 2c . . . and connected to a power cylinder 5c.