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US 4,681,326 AGranted
Gas lubricated piston ring assembly
AssigneeCummins Engine Company, Inc.
InventorIsoroku Kubo
Life of this patent
Estimating the term…
Abstract
A piston ring assembly wherein a piston member operating within a cylinder is lubricated by means of gas rather than oil films or solid lubricants. One ring (located near the lower end of piston) or two rings (one located near the lower end and the other near the top end of piston) trap gas between the piston and the cylinder wall to form a gas bearing area. The rings are designed to permit gas flow in one direction into the gas bearing area.
Claims6
A piston ring assembly comprising:
- a piston member,
- an annular groove in said piston member positioned proximate to the lower end of said piston member,
- a circumferentially extending ring positioned in said annular groove adapted for sealing engagement with said cylinder wall,
- said ring being dimensioned to provide a clearance between said annular groove and the bottom and the radially inward surfaces of said ring and having gas flow means on the upper surface thereof whereby upon downward movement of the said piston member gas is permitted to flow up and around said ring so as to be trapped in the axial space between said piston and said cylinder wall above said ring to thereby form a gas bearing for the piston.
1 more element
A piston ring assembly comprising:
- a piston member,
- an upper annular groove in said piston member positioned proximate to the upper end of said piston member,
- an upper circumferentially extending ring positioned in said upper annular groove adapted for sealing engagement with said cylinder wall,
- a lower annular groove in said piston member positioned proximate to the lower end of said piston member,
- a lower circumferentially extending ring positioned in said annular groove adapted for sealing engagement with said cylinder wall,
- said lower ring being dimensioned to provide a clearance between said annular groove and the bottom and the radially inward surfaces of said ring and having gas flow means on the upper surface thereof whereby upon downward movement of the said piston member gas is permitted to flow up and around said ring so as to be trapped in the axial space between said piston and said cylinder wall above said ring to thereby form a gas bearing for the piston.
3 more elements
A piston ring assembly comprising:
- a piston member,
- an upper annular groove in said piston member positioned proximate to the upper end of said piston member,
- an upper circumferentially extending ring positioned in said upper annular groove adapted for sealing engagement with said cylinder wall,
- said upper ring being dimensioned to provide a clearance between said annular groove and the top and the radially inward surfaces of said ring and having gas flow means on the lower surface thereof whereby upon upward movement of the said piston member gas is permitted to flow down and around said ring so as to be trapped in the axial space between said piston and said cylinder wall below said ring to thereby form a gas bearing for the piston,
- a lower annular groove in said piston member positioned proximate to the lower end of said piston member,
- a lower circumferentially extending ring positioned in said annular groove adapted for sealing engagement with said cylinder wall,
- said lower ring being dimensioned to provide a clearance between said annular groove and the bottom and the radially inward surfaces of said ring and having gas flow means on the upper surface thereof whereby upon downward movement of the said piston member gas is permitted to flow up and around said ring so as to be trapped in the axial space between said piston and said cylinder wall above said ring to thereby form a gas bearing for the piston.
4 more elements
Dependencies are inferred from the claim text.