Stirling engine

#The present invention relates to a Stirling cycle engine provided with a regenerator that offers improved heat exchange efficiency.

#A conventional Stirling cycle engine is provided with, for example, a regenerator as shown in FIG. 6, which is composed of a cylindrical bobbin 3 around the outer surface of which is wound a resin film 2 having very fine irregularities 11 formed on the surface thereof so that gaps are left between different layers of the resin film 2. These gaps result from the resin film 2 having the fine irregularities 11 between different layers thereof. FIG. 7 is a side sectional view of an example of a free-piston-type Stirling cycle refrigerator provided with such a regenerator 1. First, the structure and operation of this free-piston-type Stirling cycle refrigerator 14 will be described.

#As shown in FIG. 7, the free-piston-type Stirling cycle refrigerator 14 is provided with an enclosure 6 having working gas such as helium sealed therein, a displacer 17 and a piston 18 that divide the space inside the enclosure 6 into an expansion space 20 and a compression space 19, a linear motor 21 for driving the piston 18 to reciprocate, a heat absorber 12 provided by the side of the expansion space 20 so as to absorb heat from outside, and a heat rejector 13 provided by the side of the compressed space 19 so as to reject heat to outside.

#FIG. 1 is a perspective view showing the manufacturing process of the regenerator used in a first embodiment of the invention.

#FIG. 2 is a perspective view of the regenerator used in the first embodiment of the invention.

#FIG. 3 is a side sectional view of the regenerator used in a third embodiment of the invention and a portion around it.

#In the embodiments described hereinafter, the overall structure is substantially the same as that of the conventional free-piston-type Stirling cycle refrigerator 14 shown in FIG. 7, with only the structure of the regenerator 1 varying from one embodiment to another. Therefore, in the following descriptions, such members as are referred to with the same names are identified with the same reference numerals, and overlapping explanations will not be repeated. It is to be noted that, in the present specification, a bobbin denotes a substantially cylindrical hollow or solid core around which a resin film is wound.

#FIG. 1 is a perspective view showing the manufacturing process of the regenerator 1 used in a first embodiment of the invention. A cylindrical bobbin 3 is put through a support stand 25, and around the cylindrical bobbin 3 is fitted a thin-walled cylindrical sheath 4 having a larger diameter than the cylindrical bobbin 3. The thin-walled cylindrical sheath 4 is fixed to the support stand 25 with stoppers 24. The thin-walled cylindrical sheath 4 has a slit 5 formed vertically therein.

#Next, one end of a resin film 2 is inserted through the slit 5 and is fixed to the outer surface of the cylindrical bobbin 3, and then the cylindrical bobbin 3 is rotated in the direction indicated by arrow F1 so that the resin film is farther inserted through the slit 5 as indicated by arrow F2 and is wound around the outer surface of the cylindrical bobbin 3. When the resin film 2 so would reaches the inner surface of the thin-walled cylindrical sheath 4, the rotation of the cylindrical bobbin 3 is stopped. Then, the resin film 2 is cut, and this end of the resin film 2 is fixed to an end surface of the slit 5 or to the outer surface of the thin-walled cylindrical sheath 4.