Variable thickness coatings for cylinder liners

1. A cylinder liner for an internal combustion engine comprising:

a liner body comprising an annular wall having a first variable width along a longitudinal axis of the liner body, wherein the annular wall has a first end, a second end, and a middle portion; and

a coating disposed on an interior surface of the annular wall and having a second variable width along the longitudinal axis, wherein a combination of both the annular wall and the coating define a width of the cylinder liner in a direction perpendicular to the longitudinal axis, the width being defined by both the first and second variable widths, and the width is constant along the longitudinal axis, wherein the second variable width of the coating on the annular wall decreases from the first end to the middle portion and increases from the middle portion to the second end.

2. The cylinder liner of claim 1 , wherein the coating is thicker on the interior surface near the first end and the interior surface near the second end, and the interior surface of the middle portion is not coated.

3. The cylinder liner of claim 1 , wherein the coating comprises a coating material selected from among a group consisting of ceramics, composites of ceramics and metals, metal alloys, and metal compounds.

4. The cylinder liner of claim 1 , wherein the coating on the interior surface is thicker in a region of the interior surface corresponding to a top dead center position of a piston.

5. The cylinder liner of claim 1 , wherein the coating on the interior surface is thicker in a region of the interior surface corresponding to a bottom dead center position of a piston.

6. An internal combustion engine assembly comprising:

a piston;

a liner having a liner body comprising an annular wall having a first variable width along a longitudinal axis of the liner body; and

a coating disposed on an interior surface of the annular wall having a second variable width along the longitudinal axis, wherein a combination of both the annular wall and the coating define a width of the cylinder liner in a direction perpendicular to the longitudinal axis, the width being defined by both the first and second variable widths, and the width is constant along the longitudinal axis, wherein the second variable width of the coating decreases from a first end to a middle portion of the liner and increases in width from the middle portion to a second end of the liner.

7. The internal combustion engine assembly of claim 6 , wherein the coating comprises a smaller dimension at a midstroke position of the piston than the coating adjacent at least one longitudinal end of the liner body.

8. The internal combustion engine assembly of claim 6 , wherein the coating varies linearly along the longitudinal axis of the liner body.

9. The internal combustion engine assembly of claim 6 , wherein the coating tapers from a thicker coating from the first end to a thinner coating at the middle portion of the liner.

10. The internal combustion engine assembly of claim 6 , wherein the coating comprises a coating material comprising ceramics, composites of ceramics, composites of metals, metal alloys, metal compounds, or any combination thereof.

11. The internal combustion engine assembly of claim 6 , wherein the coating on the interior surface is thicker in a region of the interior surface corresponding to a top dead center position of the piston.

12. The internal combustion engine assembly of claim 6 , wherein the coating on the interior surface is thicker in a region of the interior surface corresponding to a bottom dead center position of the piston.

13. An internal combustion engine assembly comprising:

a piston;

a liner body comprising an annular wall having a first variable width along a longitudinal axis of the liner body, wherein the annular wall has a first end, a second end, and a middle portion; and

a coating disposed on an interior surface of the annular wall and having a second variable width along the longitudinal axis, wherein a combination of both the annular wall and the coating define a width of the cylinder liner in a direction perpendicular to the longitudinal axis, the width being defined by both the first and second variable widths, and the width is constant along the longitudinal axis, wherein the second variable width of the coating on the annular wall decreases linearly from the first end to the middle portion and increases linearly from the middle portion to the second end.

14. The internal combustion engine assembly of claim 13 , wherein the coating comprises a coating material selected from among a group consisting of ceramics, composites of ceramics and metals, metal alloys, and metal compounds.

15. The internal combustion engine assembly of claim 13 , wherein the second variable width of the coating is thicker in a region of the interior surface corresponding to a top dead center position of the piston than the coating in a region of the interior surface corresponding to the middle portion.

16. The internal combustion engine assembly of claim 13 , wherein the second variable width of the coating is thicker in a region of the interior surface corresponding to a bottom dead center position of the piston than the coating in a region of the interior surface corresponding to the middle portion.

17. The internal combustion engine assembly of claim 13 , wherein the piston is configured to be coupled to a connecting rod and comprises compression rings and an oil control ring disposed on a periphery of the piston.

18. The internal combustion engine assembly of claim 13 , wherein the second variable width of the coating on the annular wall decreases linearly in a substantially straight line.

19. The internal combustion engine assembly of claim 13 , wherein the second variable width is predetermined to ensure protection of the liner body from heat and contact.