Oil-cooled piston for a heat engine
AssigneeDAMPERS Societe Anonyme
InventorAndre Cornet
Life of this patent
Estimating the term…
Abstract
A piston for a heat engine has a chamber adjacent the piston head, for receiving cooling oil for cooling parts of the piston that in operation are subjected to elevated thermal stress. An oil inlet and an oil outlet provide for a suitable flow of oil into and out of the chamber, to ensure controlled cooling of the piston in particular of the piston head surface and the piston ring area. The chamber can be of annular shape so that the central part of the head surface remains uncooled. The invention is particularly suitable for a composite-structure piston.
Claims24
An oil-cooled piston comprising a crown, a radial flange and means axially offsetting said flange beneath said crown, a ring section rigidly secured to said crown and flange for piston-ring support and defining therewith a circumferentially continuous annular oil chamber axially between said flange and crown and radially within the piston-ring support region of said ring section, a cylindrical skirt rigid with said flange and extending axially downward therefrom, two laterally spaced downward projections independent of said skirt and rigid with said crown and flange at opposed radial offsets from the piston axis and in radial clearance relation with said skirt, transversely aligned wrist-pin bearing means in said projections at a location axially beneath said flange and ring section, each of said projections having an upwardly open cavity extending from the region of said wrist-pin bearing means and upwardly through said flange and thus forming a local axially downwardly extending region of the oil chamber, and inlet and outlet flow-circulating means communicating with the chamber.
An oil-cooled cylindrical piston, comprising a crown part, a ring part, and a skirt part;
- said crown part comprising a head-end closure wall, a relatively short axially downward cylindrical wall of substantially less than the outer diameter of the piston and integrally connected to said closure wall, said crown part further including a radially outward circumferentially continuous flange integrally connected to the lower end of said cylindrical wall, the outer diameter of said flange being the outer diameter of the piston, and two like laterally spaced axial projections extending downwardly from and integrally connected to said flange and cylindrical wall, said projections being at opposed radial offsets from the piston axis and having a maximum radial extent which is less than that of the piston, transversely aligned wrist-pin bearing means in said projections at a location axially offset from said flange, and each of said projections having a cavity formation which extends to the region of said bearing means and is upwardly open through said flange and external to said cylindrical wall;
- said ring part having an outer diameter matching that of the piston and an inner diameter substantially exceeding that of said cylindrical wall, said ring part having piston-ring retaining grooves in its outer wall and being peripherally continuously secured to said flange and to said closure wall to define an annular oil-cooling chamber with local extension of the chamber within said projections in the direction of said bearing means;
- said skirt part being secured to said flange and extending axially downward beyond and in radial clearance with said projections, and said crown part having inlet and outlet flow-circulating passage means communicating between the chamber and the space within said skirt part.
A cylindrical piston comprising an assembly of three separate component parts, namely, a head part of a given diameter, an annular ring part, and a cylindrical skirt part;
- said head part comprising a crown portion, a radial-flange portion, an inner peripherally continuous wall portion substantially inward of the piston diameter and integrally connecting said crown and flange portions in axially spaced relation, and two laterally spaced downward projections depending from said flange portion and inner-wall portion at opposed radial offsets from the piston axis and of maximum radial extent to clear the bore of said cylindrical skirt part, transversely aligned wrist-pin bearing means in said projections at a location axially offset from said flange portion, each of said downward projections flaring outwardly at juncture with said flange portion and having an upwardly and outwardly flaring cavity which extends through said flange portion;
- said ring part and said head part being rigidly secured to each other by two circular welds and cooperatively defining with said flaring cavities a circumferentially continuous oil chamber which extends circumferentially around said inner wall portion and which also extends locally downwardly to the region of said wrist-pin bearing means, said skirt part being rigidly secured to said flange portion and extending in axially overlapped and radially spaced relation to said downward projections, and inlet and outlet flow-circulating means communicating with said chamber.
Dependencies are inferred from the claim text.