| 摘要 |
PURPOSE:To prevent a piston from sticking due to the thermal-expansion of a wear ring 1 by forming cut portions at upper and lower edges of a groove for receiving a wear ring of a Stirling engine. CONSTITUTION:A annular groove 3a receiving a wear ring 1 for sealing a lublicating oil or the like is formed in the lower portion of a piston 3 of a Stirling engine. The upper and lower portions of the annular groove 3a are respectively provided with cut portions 3c which introduce thereinto thermally expanded portions of the over-heated wear ring 1. There has been a trend that the wear ring 1 is thermally expanded by heating so that it protrudes from the annular groove 3a into the clearance between a piston 1 and a cylinder 6. However, the provision of the cut portions eliminates the above-mentioned trend so that the piston 3 is prevented from sticking. |
