Piston for internal combustion engines and like machines
OwnerJean F. Melchiorinventor
Life of this patent
Estimating the term…
Abstract
The space within the interior cavity (7) of the piston (1) limited by the partially spherical head (5) of the connecting rod (6) is filled with a viscous, pasty or plastically ductile fluid (13), practically incompressible at the operating temperatures and pressures of the piston (1), the diameter (D) of the cylindrical support (8) which limits laterally the cavity (7) being very slightly greater than the diameter (d) of the partially spherical head (5) of the connecting rod (6) so that the clearance during operation between said support (8) and said head (5) is sufficiently minor to prevent any leakage of said fluid (13) from said space at the operating temperatures and pressures of the piston.
Claims25
A piston for sliding in cylinders of reciprocating two-stroke or four-stroke internal or external combustion engines and compressors, i.e. machines in which the working gas contained in the or each cylinder (2) by a transverse surface (10) of the piston (1) is at both high pressure and high temperature, which piston (1) has, within an externally cylindrical skirt (3), a partly spherical bearing surface (4) for receiving in the manner of a ball joint a partly spherical head (5) of a connecting rod (6), characterized in that said piston comprises an inner cavity (7) open at an end opposed to said transverse surface (10) and laterally defined at least partly by a cylindrical bearing surface of revolution (8);
- in that a space (12) defined inside the cavity (7) by the partly spherical head (5) of the rod (6) is filled with a fluid (13) which is practically incompressible and which is viscous, pasty or plastically deformable at the high operating temperatures and pressures of the piston (1);
- and in that the diameter (D) of the cylindrical bearing surface (8) is very slightly larger than the diameter (d) of the partly spherical head of the rod (6) so that the operational clearance between said cylindrical bearing surface (8) and said partly spherical head (5) is small enough to prevent any migration of said fluid (13) out of said space at the operating temperatures and pressures of the piston.
A piston for sliding in the cylinders of reciprocating two-stroke or four-stroke internal or external combustion engines and compressors, i.e. machines in which a working gas contained in the or each cylinder (2) by a transverse surface (10) of the piston (1) is at both high pressure and high temperature, which piston (1) receives in the manner of a ball joint a partly spherical head (5) of a connecting rod (6), characterized in that said piston comprises, within an externally cylindrical skirt (3), an inner cavity (7) which is open at an end opposed to said transverse surface (10) and laterally defined at least partly by a cylindrical bearing surface of revolution (8) which is coaxial with the piston (1);
- in that there is placed in said cavity (7) a thin fluidtight metal shell (9) whose shape is cylindrical in a lower part (11) thereof, which is an interference fit in the cylindrical bearing surface (8) of revolution of the piston (1) and substantially hemispherical in an upper part thereof against which bears the rod head (5);
- in that the metal shell defines, by an outer surface (9b) of the substantially hemispherical part thereof, inside the inner cavity (7) of the piston (1), a space (12) filled with a viscous, pasty or plastically-deformable fluid which is practically incompressible at the operating temperatures and pressures of the piston (1);
- and in that the outside diameter (d) of the partly spherical head (5) of the rod (6) is slightly less than the diameter (D) of the cylindrical bearing surface (8) of the piston (1) so that the cylindrical part (11) of the shell (9) is an interference fit in the aforementioned manner and any migration of said fluid out of said space (12) is prevented at the operating temperatures and pressures of the piston (1).
Dependencies are inferred from the claim text.