Piston Assembly for a Stirling Engine
OwnerStefan Johansson, Christopher Domanskiinventors
Life of this patent
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Abstract
A piston assembly for a double-acting engine such as a double-acting Stirling engine. A pair of sealing rings located on opposite sides of a land ring are positioned between a base section and a dome section of a piston head. These sealing rings are alternatively urged into sealing engagement with the cylinder bore as the piston reciprocates. The ring assembly further features selected rings with radial gaps used with annular non-split rings. An expander ring is further provided to radially bias the sealing rings with radial gaps. The piston assembly further features assembly features and component configurations providing excellent piston gas sealing and durability performance.
Claims29
A piston assembly for a Stirling cycle engine of the type having two or more of the piston assemblies reciprocating within cylinder bores, each of the piston assemblies separating isolated cycle volumes of a working gas contained within the engine, the piston assembly comprising:
- a piston dome forming a top end and a bottom end, the dome having a hollow interior,
- a base affixed to the piston dome bottom end,
- a connecting rod affixed to the base,
- an upper and a lower ring set positioned within a ring groove for sealing with the cylinder bore, and
- a land ring positioned within the ring groove between the upper and lower ring sets, a first ring of the upper ring set positioned on a side of the land ring toward the dome top end and the second ring of the upper ring set positioned below the first ring and adjacent to the land ring, a first ring of the lower ring set positioned on a side of the land ring toward the base, and a second ring of the lower ring set positioned between the first ring of the lower ring set and the land ring.
A piston assembly for a Stirling cycle engine of the type having two or more of the piston assemblies reciprocating within cylinder bores, each of the piston assemblies separating isolated cycle volumes of a working gas contained within the engine, the piston assembly comprising:
- a piston dome forming a top end and a open bottom end, the dome having a hollow interior,
- a base affixed to the piston dome at the bottom end,
- a connecting rod affixed to the base,
- upper and lower ring sets positioned within a ring groove, and
- a land ring positioned within the ring groove between the upper and lower ring sets, the land ring having an outer diameter surface which has a radial clearance with the surface of the cylinder bore, a first ring of the upper ring set positioned on a side of the land ring toward the dome top end and the second ring of the upper ring set positioned below the first ring and adjacent to the land ring, a first ring of a lower ring set positioned on a side of the land ring toward the base, and a second ring of the lower ring set positioned between the first ring of the lower ring set and the land ring, and
- an upper expander ring and a lower expander ring each respectively positioned radially inboard of the upper and lower ring sets and each formed of an elastomeric material and each having a lip engaging respectively the first ring of each of the upper and the lower ring sets.
Dependencies are inferred from the claim text.