Sealing ring gland and fuel pump including the same

1. A sealing ring gland which receives a sealing ring therein, said sealing ring gland comprising:

an inner wall surface which circumferentially surrounds an axis, said inner wall surface being configured to circumferentially seal against an inner periphery of said sealing ring;

an outer wall surface which circumferentially surrounds said axis and is radially offset from said inner wall surface, said outer wall surface being configured to circumferentially seal against an outer periphery of said sealing ring;

an upper wall surface which is transverse to said axis and which is configured to axially compress said sealing ring; and

a lower wall surface which is transverse to said axis and axially offset from said upper wall surface and which is configured to axially compress said sealing ring when said sealing ring is axially compressed by said upper wall surface;

wherein at least one of said upper wall surface and said lower wall surface includes an expansion volume which is recessed into said at least one of said upper wall surface and said lower wall surface, thereby providing space for said sealing ring to expand upon swelling of said sealing ring; and

wherein said expansion volume comprises a plurality of circumferentially spaced recesses which are recessed into said at least one of said upper wall surface and said lower wall surface.

2. A sealing ring gland as in claim 1 , wherein said at least one of said upper wall surface and said lower wall surface is circumferentially segmented by said plurality of circumferentially spaced recesses.

3. A sealing ring gland as in claim 2 , wherein said plurality of circumferentially spaced recesses cumulatively extend at least 90° around said axis.

4. A sealing ring gland as in claim 2 , wherein:

said upper wall surface and said lower wall surface are axially offset from each other by a first distance; and

each of said plurality of circumferentially spaced recesses are recessed into said at least one of said upper wall surface and said lower wall surface a second distance which is which is greater than or equal to 10% of said first distance and which less than or equal to 50% of said first distance.

5. A sealing ring gland which receives a sealing ring therein, said sealing ring gland comprising:

an inner wall surface which circumferentially surrounds an axis, said inner wall surface being configured to circumferentially seal against an inner periphery of said sealing ring;

an outer wall surface which circumferentially surrounds said axis and is radially offset from said inner wall surface, said outer wall surface being configured to circumferentially seal against an outer periphery of said sealing ring;

an upper wall surface which is transverse to said axis and which is configured to axially compress said sealing ring; and

a lower wall surface which is transverse to said axis and axially offset from said upper wall surface and which is configured to axially compress said sealing ring when said sealing ring is axially compressed by said upper wall surface;

wherein at least one of said upper wall surface and said lower wall surface includes an expansion volume which is recessed into said at least one of said upper wall surface and said lower wall surface, thereby providing space for said sealing ring to expand upon swelling of said sealing ring; and

wherein said expansion volume comprises a first plurality of circumferentially spaced recesses which are recessed into said upper wall surface and also comprises a second plurality of circumferentially spaced recesses which are recessed into said lower wall surface.

6. A sealing ring gland as in claim 5 , wherein:

said at said upper wall surface is circumferentially segmented by said first plurality of circumferentially spaced recesses; and

said at said lower wall surface is circumferentially segmented by said second plurality of circumferentially spaced recesses.

7. A sealing ring gland as in claim 6 , wherein each of said first plurality of circumferentially spaced recesses are axially aligned with a respective one of said second plurality of circumferentially spaced recesses.

8. A sealing ring gland as in claim 5 , wherein each of said first plurality of circumferentially spaced recesses are axially aligned with a respective one of said second plurality of circumferentially spaced recesses.

9. A sealing ring gland as in claim 5 , wherein:

said first plurality of circumferentially spaced recesses cumulatively extend at least 90° around said axis; and

said second plurality of circumferentially spaced recesses cumulatively extend at least 90° around said axis.

10. A sealing ring gland as in claim 5 , wherein:

said upper wall surface and said lower wall surface are axially offset from each other by a first distance;

each of said first plurality of circumferentially spaced recesses are recessed into said upper wall surface a second distance which is greater than or equal to 10% of said first distance and which is less than or equal to 50% of said first distance; and

each of said second plurality of circumferentially spaced recesses are recessed into said lower wall surface a third distance which is less than or equal to 50% of said first distance.

11. A fuel pump comprising:

an upper plate having an upper plate flow channel formed in a lower surface thereof;

a lower plate having a lower plate flow channel formed in an upper surface thereof such that said upper surface of said lower plate faces toward said lower surface of said upper plate;

a pumping element located axially between said upper plate and said lower plate such that rotation of said pumping element causes fuel to be drawn into, and pressurized within, said upper plate flow channel and said lower plate flow channel; and

a sealing ring which is resilient and compliant and located within a sealing ring gland, said sealing ring gland comprising:

an inner wall surface which circumferentially surrounds an axis such that said sealing ring circumferentially seals against an inner periphery of said sealing ring;

an outer wall surface which circumferentially surrounds said axis and is radially offset from said inner wall surface, said outer wall surface seals circumferentially sealing against an outer periphery of said sealing ring;

an upper wall surface which is transverse to said axis and which is configured to axially compress said sealing ring; and

a lower wall surface which is transverse to said axis and axially offset from said upper wall surface, said sealing ring being axially compressed by said upper wall surface and said lower wall surface such that axial compression of said sealing ring compresses said upper plate and said lower plate against each other;

wherein at least one of said upper wall surface and said lower wall surface includes an expansion volume which is recessed into said at least one of said upper wall surface and said lower wall surface, thereby providing space for said sealing ring to expand upon swelling of said sealing ring;

wherein said expansion volume comprises a plurality of circumferentially spaced recesses which are recessed into said at least one of said upper wall surface and said lower wall surface.

12. A fuel pump as in claim 11 wherein:

said plurality of circumferentially spaced recesses is a first plurality of circumferentially spaced recesses which are recessed into said upper wall surface; and

said expansion volume further comprises a second plurality of circumferentially spaced recesses which are recessed into said lower wall surface.

13. A fuel pump as in claim 12 , wherein:

said at said upper wall surface is circumferentially segmented by said first plurality of circumferentially spaced recesses; and

said at said lower wall surface is circumferentially segmented by said second plurality of circumferentially spaced recesses.

14. A fuel pump as in claim 13 , wherein each of said first plurality of circumferentially spaced recesses are axially aligned with a respective one of said second plurality of circumferentially spaced recesses.

15. A fuel pump as in claim 12 , wherein each of said first plurality of circumferentially spaced recesses are axially aligned with a respective one of said second plurality of circumferentially spaced recesses.

16. A fuel pump as in claim 12 , wherein:

said first plurality of circumferentially spaced recesses cumulatively extend at least 90° around said axis; and

said second plurality of circumferentially spaced recesses cumulatively extend at least 90° around said axis.

17. A fuel pump as in claim 12 , wherein:

said upper wall surface and said lower wall surface are axially offset from each other by a first distance;

each of said first plurality of circumferentially spaced recesses are recessed into said upper wall surface a second distance which is greater than or equal to 10% of said first distance and which is less than or equal to 50% of said first distance; and

each of said second plurality of circumferentially spaced recesses are recessed into said lower wall surface a third distance which is less than or equal to 50% of said first distance.

18. A fuel pump as in claim 11 , wherein said at least one of said upper wall surface and said lower wall surface is circumferentially segmented by said plurality of circumferentially spaced recesses.

19. A fuel pump as in claim 11 , wherein said plurality of circumferentially spaced recesses cumulatively extend at least 90° around said axis.

20. A fuel pump as in claim 11 , wherein:

said upper wall surface and said lower wall surface are axially offset from each other by a first distance; and

each of said plurality of circumferentially spaced recesses are recessed into said at least one of said upper wall surface and said lower wall surface a second distance which is greater than or equal to 10% of said first distance and which is less than or equal to 50% of said first distance.