Powder-lubricant piston ring for diesel engines

Claim 2

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; and p1 at least one powder-lubricated ring circumferentially extending around said piston head, said at least one powder-lubricated ring including means for providing a wedge profile impinging against said cylinder during movement of said piston with respect to said cylinder, wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder, and wherein said lubricant powder achieves quasi-hydrodynamic flow between the piston and the cylinder.

Claim 3

The piston of claim 1 further including a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a chamber within the piston.

Claim 4

In a diesel engine fueled by coal-water slurry, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a debris chamber within the piston; said distal portion including a particulate return valve communicating from said debris chamber to said combustion chamber wherein residue from said coal-water slurry is returned from said debris chamber to said combustion chamber; and at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder.

Claim 5

In a diesel engine fueled by coal-water slurry, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a debris chamber within the piston; said distal portion including a particulate return valve communicating from said debris chamber to said combustion chamber wherein residue from said coal-water slurry is returned from said debris chamber to said combustion chamber; and at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder.

Claim 6

The piston of claim 3 further including at least one ring circumferentially extending around said proximal end impinging against said wall of said cylinder.

Claim 7

The piston of claim 4 wherein said at least one ring of said proximal end is lubricated by liquid hydrocarbons.

Claim 8

The piston of claim 3 wherein an outer diameter of said piston head is reduced to allow mixing of ash of the coal-water slurry with said lubricant powder.

Claim 9

The piston of claim 3 wherein said at least one powder-lubricated ring includes an L-shaped radial cross section with a first portion extending perpendicular to said wall of said cylinder into a lateral circumferential channel in said piston head and a second portion extending parallel to said wall of said cylinder toward said combustion chamber, wherein said second portion extends outward toward said wall of said cylinder in response to combustion-generated pressure in said combustion chamber.

Claim 10

The piston of claim 7 wherein a diameter of said piston head adjacently distal to said lateral circumferential channel is less than a diameter of said piston head adjacently proximal to said lateral circumferential channel.

Claim 11

The piston of claim 3 wherein said at least one powder-lubricated ring includes a T-shaped radial cross section with a leg portion extending perpendicular to said wall of said cylinder into a lateral circumferential channel in said piston head and a distal wedge-shaped arm portion and a proximal wedge-shaped arm portion extending parallel to said wall of said cylinder, wherein said distal wedge-shaped arm portion flexes outward toward said wall of said cylinder in response to combustion-generated pressure in said combustion chamber.

Claim 12

The piston of claim 2 wherein the diesel engine uses a substantially adiabatic cycle and wherein said at least one powder-lubricated ring reaches temperatures in excess of 500° F.

Claim 13

The piston of claim 10 further including at least one ring circumferentially extending around said proximal end impinging against said wall of said cylinder.

Claim 14

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; at least one ring circumferentially extending around said proximal end impinging against said wall of said cylinder; a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a chamber within the piston; at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder; and wherein at least one ring of said proximal end is lubricated by liquid hydrocarbons.

Claim 15

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; at least one ring circumferentially extending around said proximal end impinging against said wall of said cylinder; a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a chamber within the piston; at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder; and wherein at least one ring of said proximal end is lubricated by liquid hydrocarbons.

Claim 16

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a chamber within the piston; at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder; and wherein said at least one powder-lubricated ring includes an L-shaped radial cross section with a first portion extending perpendicular to said wall of said cylinder into a lateral circumferential channel in said piston head and a second portion extending parallel to said wall of said cylinder toward said combustion chamber, wherein said second portion extends outward toward said wall of said cylinder in response to combustion-generated pressure in said combustion chamber.

Claim 17

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; a heat dam between said distal end and said proximal end, said heat dam including a portion of substantially decreased diameter thereby forming a chamber within the piston; at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder; and wherein said at least one powder-lubricated ring includes an L-shaped radial cross section with a first portion extending perpendicular to said wall of said cylinder into a lateral circumferential channel in said piston head and a second portion extending parallel to said wall of said cylinder toward said combustion chamber, wherein said second portion extends outward toward said wall of said cylinder in response to combustion-generated pressure in said combustion chamber.

Claim 18

The piston of claim 13 wherein a diameter of said piston head adjacently distal to said lateral circumferential channel is less than a diameter of said piston head adjacently proximal to said lateral circumferential channel.

Claim 19

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; a heat dam between said distal end and said proximal end, said head dam including a portion of substantially decreased diameter thereby forming a chamber within the piston; at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder; and wherein said at least one powder-lubricated ring includes a T-shaped radial cross section with a leg portion extending perpendicular to said wall of said cylinder into a lateral circumferential channel in said piston head and a distal wedge-shaped arm portion and a proximal wedge-shaped arm portion extending parallel to said wall of said cylinder, wherein said distal wedge-shaped arm portion flexes outward toward said wall of said cylinder in response to combustion-generated pressure in said combustion chamber.

Claim 20

In a diesel engine, a piston comprising: a distal end including a piston head impinging upon a combustion chamber formed between the piston and a cylinder of the diesel engine; a proximal end including means for attaching the piston to a reciprocating arm means; a heat dam between said distal end and said proximal end, said head dam including a portion of substantially decreased diameter thereby forming a chamber within the piston; at least one powder-lubricated ring circumferentially extending around said piston head wherein lubricant powder is disposed between said powder-lubricated ring and a wall of said cylinder; and wherein said at least one powder-lubricated ring includes a T-shaped radial cross section with a leg portion extending perpendicular to said wall of said cylinder into a lateral circumferential channel in said piston head and a distal wedge-shaped arm portion and a proximal wedge-shaped arm portion extending parallel to said wall of said cylinder, wherein said distal wedge-shaped arm portion flexes outward toward said wall of said cylinder in response to combustion-generated pressure in said combustion chamber.

Claim 21

The piston of claim 12 wherein the diesel engine uses a substantially adiabatic cycle and wherein said at least one powder-lubricated ring reaches temperatures in excess of 500° F.

Claim 22

The piston of claim 13 wherein the diesel engine uses a substantially adiabatic cycle and wherein said at least one powder-lubricated ring reaches temperatures in excess of 500° F.

Claim 23

The piston of claim 15 wherein the diesel engine uses a substantially adiabatic cycle and wherein said at least one powder-lubricated ring reaches temperatures in excess of 500° F.