Abstract: A Stirling engine seal assembly includes a seal ring body and an expander. The seal ring body consists of a matrix made of polytetrafluoroethylene compounded and filled with carbon fibers and at least one powder selected from the group consisting of carbon powder, boron nitride powder and molybdenum disulfide powder. The plate expander is in abutting contact with the inner peripheral surface of the seal ring body for urging the seal ring body in the direction of its outer circumference.

Abstract: An oil seal assembly includes an oil seal having a lip contacting the outer peripheral surface of a reciprocating shaft, a holder for holding the oil seal about the shaft, and an annular spring for urging the lip against the outer peripheral surface of the shaft. The lip has a flat surface which is inclined with respect to the outer peripheral surface of the shaft. When the oil seal is mounted on the shaft, the flat surface is brought into surface contact with the outer peripheral surface of the shaft by an urging force applied by the spring.

Abstract: A sealing ring assembly comprises a synthetic resin sealing ring body having two opposing stepped cut surface portions including respective planer portions in sliding contact with each other, a synthetic resin gas sealing ring in contact with the inner circumferential surface of the sealing ring body, and a metal ring in contact with the inner circumferential surface of the gas sealing ring. To prevent the stepped cut surface portions from sticking to each other at the planar portions thereof, a metal film layer is provided on a planar portion of one of the stepped cut surface portions.