Cylinder cooling in opposed-piston engines

1. A cylinder assembly for an opposed-piston engine, comprising:

a cylinder liner with a sidewall, comprising:

longitudinally-spaced exhaust and intake ports opening through the cylinder liner sidewall;

a bore; and

a sleeve sidewall with:

a first plurality of cooling feed channels that extend along the cylinder sidewall from a combustion area of the cylinder liner toward the exhaust port; and

a second plurality of cooling feed channels that extend along the cylinder sidewall from the combustion area of the cylinder liner toward the intake port; and

a sleeve covering a center section of the cylinder sidewall, the sleeve comprising:

a sleeve sidewall with a plurality of impingement jet ports that are arranged in at least one sequence extending around the combustion area and that are in liquid communication with the plurality of cooling feed channels; and

an inside surface with spaced-apart first and second annular recesses defining liquid coolant reservoirs on the cylinder sidewall, the first annular recess in liquid communication with the first plurality of feed cooling channels and the second annular recess in liquid communication with the second plurality of feed cooling channels,

each cooling feed channel comprising a tangential outlet that curves into one of the coolant reservoirs in a direction that is tangential to the coolant reservoir.

2. The cylinder assembly of claim 1 , further comprising a central rib in the combustion area of the cylinder liner.

3. The cylinder assembly of claim 1 , further comprising:

a first annular groove in the cylinder liner sidewall located between the exhaust port and the first plurality of cooling feed channels, the first annular groove located adjacent to the first plurality of cooling feed channels; and

a second annular groove in the cylinder liner sidewall located between the intake port and the second plurality of cooling feed channels, the second annular groove located adjacent to the second plurality of cooling feed channels.

4. The cylinder assembly of claim 3 , further comprising one or more bypass ports that provides a fluid flow path from a coolant reservoir formed by the first annular recess in the cylinder liner and the first annular recesses of the sleeve, through the sleeve sidewall on an exhaust side of the cylinder liner, each bypass port having sidewalls that are at an angle ⊖ E from a line perpendicular to a tangent line taken on an inner surface of the sleeve at the bypass port.

5. The cylinder assembly of claim 3 , wherein each cooling feed channel, including its tangential outlet, is configured so that in use:

coolant flow through cooling feed channels between the combustion area and the first annular groove in the cylinder liner sidewall is in a first direction; and

coolant flow through cooling feed channels between the combustion area and the second annular groove in the cylinder liner sidewall is in a second direction.

6. The cylinder assembly of claim 5 , wherein the first direction is different from the second direction.

7. The cylinder assembly of claim 6 , wherein the first direction is substantially opposite that of the second direction.

8. The cylinder assembly of claim 6 , wherein the first direction is from the combustion area toward the intake port and the second direction is from the combustion area toward the exhaust port.

9. The cylinder assembly of claim 6 , wherein:

the tangential outlet of each coolant feed channel located between the combustion area and the first annular groove is configured to cause coolant flow in a clockwise direction in a first coolant reservoir defined by the first annular groove and the first annular recesses of the sleeve; and

the tangential outlet of each coolant feed channel located between the combustion area and the second annular groove is configured to cause coolant flow in a counterclockwise direction in a second coolant reservoir defined by the second annular groove and the second annular recesses of the sleeve.

10. The cylinder assembly of claim 6 , wherein:

the tangential outlet of each coolant feed channel located between the combustion area and the first annular groove is configured to cause coolant flow in a counterclockwise direction in a first coolant reservoir defined by the first annular groove and the first annular recesses of the sleeve; and

the tangential outlet of each coolant feed channel located between the combustion area and the second annular groove is configured to cause coolant flow in a clockwise direction in a second coolant reservoir defined by the second annular groove and the second annular recesses of the sleeve.

11. A cylinder for an opposed-piston engine, comprising:

a sidewall;

a bore;

longitudinally-spaced exhaust and intake ports opening through the sidewall, into the bore; and

a first plurality of cooling feed channels that extend along the sidewall from a combustion area of the cylinder toward the exhaust port;

a first annular coolant reservoir on the sidewall in liquid communication with the first plurality of cooling feed channels;

a second plurality of cooling feed channels that extend along the sidewall from a combustion area of the cylinder toward the intake port; and,

a second annular coolant reservoir on the sidewall in liquid communication with the second plurality of cooling feed channels; wherein,

each of the first cooling feed channels comprises a tangential outlet that curves into the first coolant reservoir in a direction that is tangential to the first coolant reservoir; and,

each of the second cooling feed channels comprises a tangential outlet that curves into the second coolant reservoir in a direction that is tangential to the second coolant reservoir.

12. The cylinder of claim 11 , further comprising a central rib in the combustion area of the cylinder liner.

13. The cylinder of claim 11 , further comprising:

a first annular groove in the cylinder liner sidewall located between the intake port and the plurality of cooling feed channels, the first annular groove located adjacent to the plurality of cooling feed channels; and

a second annular groove in the cylinder liner sidewall located between the exhaust port and the plurality of cooling feed channels, the second annular groove located adjacent to the plurality of cooling feed channels.

14. The cylinder of claim 13 , further comprising one or more bypass ports that provides a fluid flow path from a coolant reservoir formed by the second annular recess in the cylinder liner and one of the spaced-apart annular recesses of the sleeve, through the sleeve sidewall on an exhaust side of the cylinder liner, each bypass port having sidewalls that are at an angle ⊖ E from a line perpendicular to a tangent line taken on an inner surface of the sleeve at the bypass port.

15. The cylinder of claim 13 , wherein each cooling feed channel, including its tangential outlet, is configured so that in use:

coolant flow through cooling feed channels between the combustion area and the first annular groove in the cylinder liner sidewall is in a first direction; and

coolant flow through cooling feed channels between the combustion area and the second annular groove in the cylinder sidewall is in a second direction.

16. The cylinder of claim 15 , wherein the first direction is different from the second direction.

17. The cylinder of claim 16 , wherein the first direction is substantially opposite that of the second direction.

18. The cylinder of claim 16 , wherein the first direction is from the combustion area toward the intake port and the second direction is from the combustion area toward the exhaust port.

19. The cylinder of claim 16 , wherein:

the tangential outlet of each coolant feed channel located between the combustion area and the first annular groove is configured to cause coolant flow in a clockwise direction in a first coolant reservoir defined by the first annular groove and a first of the spaced-apart annular recesses of the sleeve; and

the tangential outlet of each coolant feed channel located between the combustion area and the second annular groove is configured to cause coolant flow in a counterclockwise direction in a second coolant reservoir defined by the second annular groove and a second of the spaced-apart annular recesses of the sleeve.

20. The cylinder assembly of claim 16 , wherein;

the tangential outlet of each coolant feed channel located between the combustion area and the first annular groove is configured to cause coolant flow in a counterclockwise direction in a first coolant reservoir defined by the first annular groove and a first of the spaced-apart annular recesses of the sleeve; and

the tangential outlet of each coolant feed channel located between the combustion area and the second annular groove is configured to cause coolant flow in a clockwise direction in a second coolant reservoir defined by the second annular groove and a second of the spaced-apart annular recesses of the sleeve.