Piston ring and method of manufacture
AssigneeMahle International GmbH
InventorsJose Valentim Lima Sarabanda, Fabio Mendes de Araujo
Life of this patent
Estimating the term…
Abstract
A piston ring may include a split annular body having a plurality of exterior surfaces, an intermediate coating disposed on and directly contacting at least one exterior surface of the split annular body, and a tribological coating. The tribological coating may include a first layer disposed on and directly contacting the intermediate coating, and a second layer disposed on and directly contacting the first layer. The first layer may have a first hardness and a first porosity. The second layer may have a second hardness and a second porosity. The second hardness may be less than the first hardness. The second porosity may be greater than the first porosity.
Claims16
A piston ring, comprising:
- a split annular body having a plurality of exterior surfaces;
- an intermediate coating disposed on and directly contacting at least one surface of the plurality of exterior surfaces;
- a tribological coating including:
- a first layer disposed on and directly contacting the intermediate coating, the first layer having a first hardness and a first porosity;
- and
- a second layer disposed on and directly contacting the first layer, the second layer having a second hardness and a second porosity;
- wherein the second hardness is less than the first hardness;
- wherein the second porosity is greater than the first porosity;
- wherein the first layer has a first material composition;
- and
- wherein the second layer has a second material composition that is the same as the first material composition.
A piston ring, comprising a split annular body having a plurality of exterior surfaces, wherein:
- at least one surface of the plurality of exterior surfaces includes a first intermediate coating layer disposed directly thereon;
- at least one other surface of the plurality of exterior surfaces includes a second intermediate coating layer disposed directly thereon, a first tribological coating layer disposed on and directly contacting the second intermediate coating layer, and a second tribological coating layer disposed on and directly contacting the first tribological coating layer;
- the first tribological coating layer has a first hardness;
- the second tribological coating layer has a second hardness;
- the second hardness is less than the first hardness;
- the first tribological coating layer has a first material composition;
- and
- the second tribological coating layer has a second material composition that is the same as the first material composition.
Dependencies are inferred from the claim text.