Multi-layered piston crown for opposed-piston engines
AssigneeAchates Power, Inc.
InventorsBryant A. Wagner, Ryan G. MacKenzie
Life of this patent
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Abstract
A piston crown for a piston of a pair of pistons in a two-stroke, opposed-piston, compression ignition combustion engine has a barrier layer and a conductive layer. The barrier layer at least partially surrounds a combustion chamber formed by the piston crown and an end surface of an opposing piston. The conductive layer connects the crown to the rest of the piston body. The barrier layer and the conductive layer are joined either through welding or through the fabrication process. Optionally, the piston crown includes an insulating layer between the barrier and conductive layers.
Claims19
An internal combustion engine including at least one cylinder with longitudinally-separated exhaust and intake ports and a pair of pistons disposed in opposition to one another in a bore of the cylinder, each piston including:
- a piston body with a crown at one end;
- and
- an end surface on the crown, in which an end surface of a first piston has a bowl that cooperates with the end surface of an opposing piston to define a combustion chamber,
- the crown comprising:
- a barrier layer located in the end surface such that the combustion chamber is enclosed at least in part by the barrier layer;
- an insulating layer;
- and
- a conductive layer located adjacent to the barrier layer, the conductive layer connecting the crown to the piston body by welding above piston ring grooves,
- in which:
- the insulating layer is between the barrier layer and the conductive layer,
- the barrier layer and the conductive layer each have a bowl, a pair of notches, and a sidewall portion, and
- the insulating layer does not have a sidewall portion and has a circumference that fits within the sidewall portion of the barrier layer.
A piston for a two-stroke, opposed-piston, internal combustion engine, comprising:
- a piston body with a crown at one end, the crown including;
- an end surface formed on the crown, the end surface including an elongated bowl that cooperates with an opposing piston end surface to define a combustion chamber, a barrier layer located in the end surface such that the combustion chamber is enclosed at least in part by the barrier layer;
- an insulating layer between the barrier layer and the conductive layer, the insulating layer having a thermal conductivity of 2 W/m-C or less;
- a conductive layer located adjacent to the barrier layer, the conductive layer connecting the crown to the rest of piston body;
- and at least one void formed from a discontinuity between the barrier layer and the conductive layer, in which:
- the barrier layer and the conductive layer each have a bowl, a pair of notches, and a sidewall portion, the barrier layer and the conductive layer are joined along their respective sidewall portions, and the crown is attached to the piston body above piston ring grooves by welding.
A method of making a piston crown for a piston for a two-stroke, opposed-piston, internal combustion engine, the method comprising:
- forming a barrier layer configured to at least partially enclose a combustion chamber formed by the piston crown and an end surface of an opposing piston;
- forming a conductive layer configured to connect the piston crown to other components of the piston;
- forming an insulating layer configured for insertion between the barrier layer and the conductive layer;
- and
- joining the barrier layer and the conductive layer,
- in which:
- the barrier layer and the conductive layer each have a bowl, a pair of notches, and a sidewall portion;
- and
- the insulating layer does not have a sidewall portion and has a circumference that fits within the sidewall portion of the barrier layer.
Dependencies are inferred from the claim text.