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 such that said expansion volume intersects with said at least one of said upper wall surface and said lower wall surface, wherein said expansion volume either (i) intersects with said upper wall surface, extends radially outward from said inner wall surface, and terminates radially outward at a location between said inner wall surface and said outer wall surface, or (ii) intersects with said lower wall surface, extends radially inward from said outer wall surface, and terminates radially inward at a location between said inner wall surface and said outer wall surface, or (iii) both (i) and (ii), and said expansion volume has a width in the radial direction that is less than 50% of a diameter of said sealing ring, thereby providing space for said sealing ring to expand upon swelling of said sealing ring.

2. A sealing ring gland as in claim 1 , wherein:

said upper wall surface is annular in shape and extends uninterrupted for 360° around said axis;

said lower wall surface is annular in shape and extends uninterrupted for 360° around said axis; and

said expansion volume comprises a first recess which is annular in shape and which intersects with said upper wall surface and also comprises a second recess which is annular in shape and which intersects with said lower wall surface.

3. 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;

said first recess is recessed into said upper 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; and

said second recess is recessed into said lower wall surface a third 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.

4. A sealing ring gland as in claim 1 , wherein one or both of said upper wall surface and said lower wall surface is annular in shape and extends uninterrupted for 360° around said axis.

5. A sealing ring gland as in claim 1 , wherein said expansion volume is annular in shape.

6. A sealing ring gland as in claim 1 , wherein:

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

said expansion volume is 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.

7. A sealing ring gland as in claim 1 , wherein:

said expansion volume intersects with both said upper wall surface and said lower wall surface;

said expansion volume extends radially outward from said inner wall surface and terminates radially outward at a location between said inner wall surface and said outer wall surface; and

said expansion volume extends radially inward from said outer wall surface and terminates radially inward at a location between said inner wall surface and said outer wall surface.

8. A sealing ring gland as in claim 1 , wherein said upper wall surface and said lower wall surface each define a shoulder having a width that is greater than 50% of the diameter of said sealing ring.

9. 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, such that said expansion volume intersects with said at least one of said upper wall surface and said lower wall surface, wherein said expansion volume either (i) intersects with said upper wall surface, extends radially outward from said inner wall surface, and terminates radially outward at a location between said inner wall surface and said outer wall surface, or (ii) intersects with said lower wall surface, extends radially inward from said outer wall surface, and terminates radially inward at a location between said inner wall surface and said outer wall surface, or (iii) both (i) and (ii), and said expansion volume has a width in the radial direction that is less than 50% of a diameter of said sealing ring, thereby providing space for said sealing ring to expand upon swelling of said sealing ring.

10. A fuel pump as in claim 9 , wherein:

said upper wall surface is annular in shape and extends uninterrupted for 360° around said axis;

said lower wall surface is annular in shape and extends uninterrupted for 360° around said axis; and

said expansion volume comprises a first recess which is annular in shape and which intersects with said upper wall surface and also comprises a second recess which is annular in shape and which intersects with said lower wall surface.

11. A fuel pump as in claim 10 , wherein:

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

said first recess is recessed into said upper 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; and

said second recess is recessed into said lower wall surface a third 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.

12. A fuel pump as in claim 9 , wherein one or both of said upper wall surface and said lower wall surface is annular in shape and extends uninterrupted for 360° around said axis.

13. A fuel pump as in claim 9 , wherein said expansion volume is annular in shape.

14. A fuel pump as in claim 9 , wherein

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

said expansion volume is 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.

15. A fuel pump as in claim 9 , wherein:

said expansion volume intersects with both said upper wall surface and said lower wall surface;

said expansion volume extends radially outward from said inner wall surface and terminates radially outward at a location between said inner wall surface and said outer wall surface; and

said expansion volume extends radially inward from said outer wall surface and terminates radially inward at a location between said inner wall surface and said outer wall surface.

16. A fuel pump as in claim 9 , wherein said upper wall surface and said lower wall surface each define a shoulder having a width that is greater than 50% of the diameter of said sealing ring.