FLEXIBLE FILM-RIDING SEAL

• US 20160115805A1
• Filed: 10/08/2015
• Published: 04/28/2016
• Est. Priority Date: 10/28/2014
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: BIDKAR, Rahul Anil, GIBSON, Nathan Evan McCurdy, THATTE, Azam Mihir, SHASTRY, Narayana, MANICKAVASAGAM SAROJINI, Hariharan
• Granted Patent: US 10,161,259 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 11/001 for sealing space between stator blade and rotor
• CPC Class Codes: F01D 11/02 by non-contact sealings, e.g. of labyrinth type for sealing space between rotor blade tips and stator F01D11/08
• CPC Class Codes: F01D 11/025 Seal clearance control; Floating assembly; Adaptation means to differential thermal dilatations
• CPC Class Codes: F01D 11/04 using sealing fluid, e.g. steam
• CPC Class Codes: F01D 11/08 for sealing space between rotor blade tips and stator specially-shaped blade tips therefor F01D5/20
• CPC Class Codes: F01D 11/10 using sealing fluid, e.g. steam
• CPC Class Codes: F01D 11/12 using a rubstrip, e.g. erodible. deformable or resiliently-biased part
• CPC Class Codes: F01D 11/14 Adjusting or regulating tip-clearance, i.e. distance between rotor-blade tips and stator casing rotors with blades adjustable in operation F01D7/00
• CPC Class Codes: F01D 11/16 by self-adjusting means F01D11/12 takes precedence
• CPC Class Codes: F16J 15/441 with floating ring

Abstract

A seal apparatus for a rotary machine, including a plurality of sealing assembly segments surrounding a rotor element which is mounted for rotation about a longitudinal axis and has an outer surface. Each of the segments includes a shoe with one or more labyrinth teeth facing the outer surface and a shoe plate disposed downstream of the one or more labyrinth seal teeth and configured to generate an aerodynamic force between the shoe plate and the outer surface of the rotor element. The shoe is further configured to be flexible in a radial-axial plane in response to fluid film forces generated by interaction of the sealing assembly segment and the rotor element, and an axially-oriented beam spring connects the shoe to a stationary seal body.

Claims

1. A seal apparatus for a rotary machine, comprising:

a plurality of sealing assembly segments surrounding a rotor element which is mounted for rotation about a longitudinal axis and has an outer surface, each of the segments comprising;

a shoe including;

one or more labyrinth teeth facing the outer surface; and

a shoe plate disposed downstream of the one or more labyrinth seal teeth and configured to generate an aerodynamic force between the shoe plate and the outer surface of the rotor element, wherein the shoe is further configured to be flexible in a radial-axial plane in response to fluid film forces generated by interaction of the sealing assembly segment and the rotor element; and

an axially-oriented beam spring connecting the shoe to a stationary seal body.

2. The seal apparatus of claim 1 wherein the seal body comprises an annular array of segments.

3. The seal apparatus of claim 1 further including a secondary seal including a leaf contacting the seal body and the shoe at upstream ends thereof, so as to seal leakage therebetween while permitting relative movement of the seal body and the shoe.

4. The seal apparatus of claim 1 wherein the shoe plate is connected to the spring by a beam so as to prevent longitudinal tilting of the shoe plate.

5. The seal apparatus of claim 4 wherein the beam is axially-oriented, with a forward end connected to a forward end of the spring, and an aft end connected to the shoe plate.

6. The seal apparatus of claim 1 wherein:

the outer surface includes a forward second and an aft section, with an aft-facing step defined therebetween;

the one or more labyrinth teeth are disposed opposite the forward section; and

the shoe plate is disposed opposite the aft section.

7. A rotary machine apparatus, comprising:

a rotor element mounted for rotation about a longitudinal axis, the rotor element having a cylindrical outer surface,

an annular stationary seal body surrounding the rotor element;

an array of axially-oriented beam springs extending from the seal body;

a shoe coupled to each of the beam springs, disposed between the rotor element and the seal body, each shoe comprising;

an annular labyrinth seal tooth facing the outer surface;

a shoe plate disposed downstream of the labyrinth seal tooth and configured to generate an aerodynamic force between the shoe plate and the outer surface, wherein the shoe is further configured to be flexible in a radial-axial plane in response to fluid film forces generated by interaction of the shoe plate and the rotor element; and

a beam interconnecting the seal tooth and the shoe plate.

8. The apparatus of claim 7 wherein the seal body comprises an annular array of segments.

9. The apparatus of claim 7 further including a secondary seal including a leaf contacting the seal body and the shoe at upstream ends thereof, so as to seal leakage therebetween while permitting relative movement of the seal body and the shoe.

10. The apparatus of claim 7 wherein the beam is configured so as to prevent longitudinal tilting of the shoe plate.

11. The apparatus of claim 10 wherein the beam is axially-oriented, with a forward end connected to the seal tooth, and an aft end connected to the shoe plate.

12. The apparatus of claim 7 wherein:

the outer surface includes a forward second and an aft section, with an aft-facing step defined therebetween;

the labyrinth tooth is disposed opposite the forward section; and

the shoe plate is disposed opposite the aft section.