Sealing ring assemblies configured for pressure locking

1. A sealing ring assembly comprising:

a first sealing element comprising a first mating surface; and

a second sealing element comprising a second mating surface;

a high-pressure boundary extending across at least a portion of the first sealing element and across at least a portion of the second sealing element;

a low-pressure boundary extending across at least a portion of the first sealing element and across at least a portion of the second sealing element;

a rear axial face configured to seal against a land of a piston; and

a radially outer face configured to seal against a bore of a cylinder between the high-pressure boundary and the low-pressure boundary;

wherein at least one of the first mating surface and the second mating surface comprises a recess open to the low-pressure boundary and not open to the high-pressure boundary, such that the first mating surface is configured to be sealed against the second mating surface by a first force acting on the first sealing element and a second force acting on the second sealing element.

2. The sealing ring assembly of claim 1 , wherein the first force acting on the first sealing element is directed opposite to the second force acting on the second sealing element.

3. The sealing ring assembly of claim 1 , wherein the recess is configured to cause the first and second forces to maintain a relative position of the first sealing element and the second sealing element.

4. The sealing ring assembly of claim 1 , wherein the recess comprises a groove.

5. The sealing ring assembly of claim 1 , wherein the recess is a first recess of the first mating surface, and wherein the second mating surface comprises a second recess configured to interface with the first recess.

6. The sealing ring assembly of claim 1 , wherein the first sealing element comprises a first ring segment, and wherein the second sealing element comprises a second ring segment.

7. the sealing ring assembly of claim 1 , wherein the first sealing element comprises a ring segment, and wherein the second sealing element comprises a gap cover element.

8. The sealing ring assembly of claim 1 , wherein at least one of the first and second sealing elements comprises a radial pressure-balancing feature, configured to cause a radially inward force.

9. The sealing ring assembly of claim 1 , wherein the first and second mating surface seal against each other to prevent the recess from being open to the high-pressure boundary.

10. A piston assembly comprising:

a piston comprising a circumferential groove; and

a sealing ring assembly arranged in the circumferential groove, the sealing ring assembly comprising:

a first sealing element comprising a first mating surface; and

a second sealing element comprising a second mating surface;

a high-pressure boundary extending across at least a portion of the first sealing element and across at least a portion of the second sealing element; and

a low-pressure boundary extending across at least a portion of the first sealing element and across at least a portion of the second sealing element;

wherein at least one of the first mating surface and the second mating surface comprises a recess open to the low-pressure boundary and not open to the high-pressure boundary, such that the first mating surface is sealed against the second mating surface by a first force acting on the first sealing element and a second force acting on the second sealing element.

11. The piston assembly of claim 10 , wherein the first force acting on the first sealing element is directed opposite to the second force acting on the second sealing element.

12. The piston assembly of claim 10 , wherein the recess is configured to cause the first and second force to maintain a relative position of the first sealing element and the second sealing element.

13. The piston assembly of claim 10 , wherein the piston further comprises a land and is configured to move within a bore of a cylinder, and wherein the sealing ring assembly further comprises:

a rear axial face configured to seal against the land; and

a radially outer face configured to seal against the bore between the high-pressure boundary and the low-pressure boundary.

14. The piston assembly of claim 10 , wherein the recess comprises a groove.

15. The piston assembly of claim 10 , wherein the recess is a first recess of the first mating surface, and wherein the second mating surface comprises a second recess configured to interface with the first recess.

16. The piston assembly of claim 10 , wherein the first sealing element comprises a first ring segment, and wherein the second sealing element comprises a second ring segment.

17. The piston assembly of claim 10 , wherein the first sealing element comprises a ring segment, and wherein the second sealing element comprises a gap cover element.

18. The piston assembly of claim 10 , wherein at least one of the first and second sealing elements comprises a radial pressure-balancing feature, configured to cause a radially inward force.

19. The piston assembly of claim 10 , wherein the first and second mating surfaces seal against each other to prevent the recess from being open to the high-pressure boundary.

20. A device comprising:

a cylinder comprising a bore comprising a high-pressure region and a low-pressure region;

a piston comprising a circumferential groove, wherein the piston is configured to move axially within the bore;

a sealing ring assembly arranged in the circumferential groove and configured to seal against the bore to define the high-pressure region and the low-pressure region, the sealing ring assembly comprising;

a first sealing element comprising a first mating surface; and

a second sealing element comprising a second mating surface;

wherein at least one of the first and second mating surfaces comprises a recess open to the low-pressure region and not open to the high-pressure region, such that the first mating surface is sealed against the second mating surface by a first force acting on the first sealing element and a second force acting on the second sealing element.

21. The device of claim 20 , wherein:

the circumferential groove further comprises an axially rear land; and

the sealing ring assembly is further configured to seal against the axially rear land.

22. The device of claim 20 , wherein the first force acting on the first sealing element is directed opposite to the second force acting on the second sealing element.

23. The device of claim 20 , wherein the recess is configured to cause the first and second forces to maintain a relative position of the first sealing element and the second sealing element.

24. The device of claim 20 , wherein the sealing ring assembly further comprises a radially outer face configured to seal against the bore.

25. The device of claim 20 , wherein the sealing ring assembly further comprises:

a first boundary extending across at least a portion of the first sealing element and at least a portion of the second sealing element, and that is open to the high-pressure region; and

a second boundary extending across at least a portion of the first sealing element and at least a portion of the second sealing element, and that is open to the low-pressure region, wherein the recess is open to the boundary and not open to the second boundary.

26. The device of claim 20 , wherein the first sealing element comprises a first ring segment, and wherein the second sealing element comprises a second ring segment.

27. The device of claim 20 , wherein the first sealing element comprises a ring segment, and wherein the second sealing element comprises a gap cover element.

28. The device of claim 20 , wherein the first and second mating surface are configured to seal against each other to prevent the recess from being open to the high-pressure region.