Piston ring with inlaid DLC coating and method of manufacturing
AssigneeTenneco Inc.
InventorBlair Matthew Jenness
Life of this patent
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Abstract
A piston ring providing improved performance during operation, including reduction in blowby gases and improved oil control, is provided. The piston ring includes an upper layer, a lower layer, and a middle layer each formed from a powder metal material. An exposed sharp first corner is present between an upper ring surface and an upper outer diameter surface, and an exposed sharp second corner is present between a lower ring surface and a lower outer diameter surface. The piston ring also comprises a coating including diamond-like carbon (DLC). The DLC coating is inlaid. Thus, the coating is disposed on the middle layer but is spaced from the upper and lower corners, so that the upper and lower corners of the piston ring are exposed.
Claims18
A piston ring, comprising:
- an upper layer extending circumferentially around a center axis, said upper layer formed of an upper powder metal material, said upper layer presents an upper ring surface, said upper layer presents an upper outer diameter surface, and a first corner is present between said upper ring surface and said upper outer diameter surface;
- a lower layer extending circumferentially around said center axis, said lower layer formed of a lower powder metal material, said lower layer presents a lower ring surface opposite said upper ring surface, said lower layer presents a lower outer diameter surface, a second corner is present between said lower outer diameter surface and said lower ring surface;
- a middle layer extending circumferentially around said center axis and disposed between said upper layer and said lower layer, said middle layer being formed of a middle powder metal material, said middle layer presenting a middle outer diameter surface between said upper outer diameter surface and said lower outer diameter surface;
- a coating including diamond-like carbon disposed on an entirety of said middle outer diameter surface of said middle layer, said coating being spaced from at least one of said corners such that said at least one corner is exposed, and wherein a coating outer diameter surface, said upper outer diameter surface, said upper ring surface, said lower ring surface, and said lower outer diameter surface are outermost surfaces on three sides of said piston ring.
A method of manufacturing a piston ring, comprising the steps of:
- providing an upper layer formed of an upper powder metal material extending circumferentially around a center axis, the upper layer presenting an upper ring surface, the upper layer presenting an upper outer diameter surface, and a first corner is present between the upper ring surface and the upper outer diameter surface;
- disposing a middle layer formed of a middle powder metal material extending circumferentially around the center axis along the upper layer, the middle layer presenting a middle outer diameter surface;
- disposing a lower layer formed of a lower powder metal material extending circumferentially around the center axis along the middle layer, the lower layer presenting a lower ring surface opposite the upper ring surface, the lower layer presenting a lower outer diameter surface, and a second corner is present between the lower outer diameter surface and the lower ring surface;
- and
- disposing a coating including diamond-like carbon on an entirety of the middle outer diameter surface of the middle layer, the coating being spaced from at least one of the corners such that the at least one corner is exposed, and wherein a coating outer diameter surface, the upper outer diameter surface, the upper ring surface, the lower ring surface, and the lower outer diameter surface are outermost surfaces on three sides of the piston ring.
Dependencies are inferred from the claim text.