Self-optimizing seal for turbomachinery, and associated systems and methods

Patent metadata

Field	Value
Publication number	US-12104699-B2
Application number	US-202217715781-A
Country	US
Kind code	B2
Filing date	Apr 7, 2022
Priority date	Apr 7, 2022
Publication date	Oct 1, 2024
Grant date	Oct 1, 2024

Abstract

A representative seal system (such as a seal system for a turbopump of a rocket engine) automatically adjusts a balance ratio of a seal. The system can include a ring element encircling an axis. A front side of the ring element contacts a revolving surface to form a seal with the revolving surface. The front side can include a stepped surface having two or more steps. Each step includes a sealing surface configured to contact the revolving surface to form a sealing area that is different from a sealing area of each other sealing surface. Each step is positioned and configured to wear away during operation of the machine to expose an underlying surface to the revolving surface, to change the sealing area and the balance ratio of the seal. A representative method of operating a turbomachinery system includes changing the balance ratio of a seal while rotating a rotor.

First claim

We claim:

1. A seal system for turbomachinery, wherein the seal system comprises a ring element encircling an axis, wherein the ring element comprises:
a radially inward surface;
a radially outward surface;
a back side extending between the radially inward surface and the radially outward surface; and
a front side positioned opposite the back side and extending between the radially inward surface and the radially outward surface, wherein the front side is positioned to contact a revolving surface of the turbomachinery;
wherein:
the front side comprises a stepped surface having two or more steps;
each step comprises a sealing surface positioned along the axis at a location that is different from a sealing surface of each other step;
each sealing surface is configured to contact the revolving surface, wherein contact between the revolving surface and the sealing surface is within a sealing area;
each sealing surface comprises a sealing area that is different from a sealing area of each other sealing surface of the two or more steps; and
the seal system further comprises a closing area sized with respect to a face area according to a balance ratio which changes between 0.5 and 1.2 as each step wears away during operation of the turbomachinery, wherein the balance ratio is expressed as a ratio of the closing area, receiving a closing force between the ring element and the revolving surface, with respect to the face area of contact between the front side and the revolving surface.

2. The seal system of claim 1 , wherein the ring element comprises a ceramic material.

3. The seal system of claim 2 , wherein the ceramic material includes carbon.

4. The seal system of claim 1 , wherein each of the two or more steps provides a balance ratio, and wherein each of the two or more steps provides a different balance ratio than each other step of the two or more steps.

5. The seal system of claim 1 , wherein the two or more steps comprises four steps.

6. The seal system of claim 1 , further comprising a biasing element positioned to bias the front side toward the revolving surface.

7. The seal system of claim 6 , wherein the biasing element comprises a spring or metal bellows.

8. A seal system for turbomachinery, wherein the seal system comprises a ring element encircling an axis, wherein the ring element comprises:
a radially inward surface;
a radially outward surface;
a back side extending between the radially inward surface and the radially outward surface; and
a front side positioned opposite the back side and extending between the radially inward surface and the radially outward surface, wherein the front side is positioned to contact a revolving surface of the turbomachinery;
wherein:
the front side comprises a stepped surface having two or more steps, wherein the two or more steps comprise a first step positioned farther from the back side than a second step;
each step comprises a sealing surface positioned along the axis at a location that is different from a sealing surface of each other step;
each sealing surface is configured to contact the revolving surface, wherein contact between the revolving surface and the sealing surface is within a sealing area;
each sealing surface comprises a sealing area that is different from a sealing area of each other sealing surface of the two or more steps;
the seal system further comprises a closing area sized with respect to a face area according to a balance ratio which changes between 0.5 and 1.2 as each step wears away during operation of the turbomachinery, wherein the balance ratio is expressed as a ratio of the closing area, receiving a closing force between the ring element and the revolving surface, with respect to the face area of contact between the front side and the revolving surface;
a portion of the radially inward surface on the first step is positioned radially outward relative to a portion of the radially inward surface on the second step; and
a portion of the radially outward surface on the first step is positioned radially inward relative to a portion of the radially outward surface on the second step.

9. The seal system of claim 8 , wherein each of the two or more steps provides a balance, and wherein each of the two or more steps provides a different balance ratio than each other step of the two or more steps.

10. The seal system of claim 8 , wherein the two or more steps comprise a third step adjacent to the second step, and wherein a radial position of the portion of the radially outward surface on the second step is the same as a radial position of a portion of the radially outward surface on the third step.

11. The seal system of claim 8 , wherein the ring element comprises a ceramic material.

12. The seal system of claim 11 , wherein the ceramic material includes carbon.

13. The seal system of claim 8 , wherein the two or more steps comprise four steps.

14. The seal system of claim 8 , further comprising a biasing element positioned to bias the front side toward the revolving surface.

15. The seal system of claim 14 , wherein the biasing element comprises a spring or metal bellows.

16. The seal system of claim 8 , wherein at least one step of the two or more steps provides a balance ratio greater than 1.0.

Assignees

• Blue Origin Llc

Inventors

• Linderman Ryan
• Mills Jacob

Classifications

• F01D11/003

  by packing rings; Mechanical seals · CPC title

• F16J15/346 Primary

  the pressing force varying during operation · CPC title

• F16J15/3412

  with cavities (F16J15/3424 takes precedence) · CPC title

• F16J15/34

  with slip-ring pressed against a more or less radial face on one member · CPC title

• F16J15/3408

  at least one ring having an uneven slipping surface · CPC title