Patent Application
20140154060
The subject matter disclosed herein relates to turbomachines, and more particularly to turbomachine seal assemblies, as well as a method of sealing a rotor region.
Dynamic sealing between a rotor (e.g., rotating shaft) and a stator (e.g., static shell or casing) is an important concern in turbomachinery. Numerous sealing approaches have been employed and typically include a primary seal structure that is prone to wearing and potentially failure. Secondary seal structures may be included to account for potential failure of the primary seal structure, but significant spatial requirements for the secondary seal structures often negatively constrain rotor design architecture. Large axial and/or radial spaces may be required to properly accommodate the secondary seal structure.
According to one aspect of the invention, a turbomachine seal assembly includes a rotor disposed about an axial centerline, the rotor having an outer surface. Also included is a stationary component extending circumferentially about the rotor. Further included is at least one primary annular seal ring operably coupled to the stationary component and extending radially inwardly to close proximity with the outer surface of the rotor. Yet further included is a secondary annular seal ring operably coupled to the stationary component and integrally formed with the at least one primary annular seal ring, the secondary annular seal ring extending radially inwardly to close proximity with the outer surface of the rotor.
According to another aspect of the invention, a method of sealing a rotor region of a turbomachine is provided. The method includes integrally forming a primary annular seal ring and a secondary annular seal ring. Also included is operably coupling the primary annular seal ring and the secondary annular seal ring to a stationary component extending circumferentially about a rotor, wherein the primary annular seal ring and the secondary annular seal ring extend radially inwardly to close proximity with an outer surface of the rotor.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
Referring to
Although illustrated and described above as a gas turbine engine, an alternative embodiment of the turbine system 10 comprises a steam turbine engine. Also, the embodiments described below may be employed with any turbomachine having a rotor region benefitting from sealing thereabout.
Referring now to
In the exemplary embodiment, the seal assembly 30 reduces axial leakage between the rotor 18 and a stationary component 34. A housing 36 is coupled to the stationary component 34, such that the rotor 18 rotates relative to the housing 36 about an axial centerline. The housing 36 may be coupled to the stationary component 34 in a number of ways, and in the illustrated embodiment the housing 36 is disposed within an annular cavity 40 of the stationary component 34 that may be characterized as having a T-shaped geometry. At least one biasing member 42 is disposed between the housing 36 and the stationary component 34 to bias the seal assembly 30 away from the rotor 18. The at least one biasing member 42 may be a coil spring, a leaf spring or any other biasing mechanism that enables the seal assembly 30 to function as described herein.
The housing 36 includes a primary seal system comprising a primary annular seal ring 50 and a plurality of plate members 52, both extending radially inwardly from the housing 36 and stationary component 34 toward the outer surface 32 of the rotor 18. As illustrated, it is to be appreciated that a plurality of primary annular seal rings may be integrally formed with or operably coupled to the housing 36. The primary annular seal ring 50 is situated at least partially within the plurality of plate members 52. Specifically, each of the plurality of plate members 52 includes a slot 54 in which the primary annular seal ring 50 is disposed within. Each of the plurality of plate members 52 is operably coupled to the housing 36 at a root end 55 and is substantially planar is geometry. The plurality of plate members 52 are spaced circumferentially around the rotor 18, thereby forming a gap 56 between each of the plurality of plate members 52. The primary annular seal ring 50 extending through the slot 54 reduces axial leakage flow between the gap 56.
The seal assembly 30 also includes a secondary annular seal ring 60 that is integrally formed with the primary annular seal ring 50. The secondary annular seal ring 60 is also integrally formed with or is operably coupled to the housing 36, extending radially inwardly therefrom. The secondary annular seal ring 60 is a robust, durable plate that provides a sealing redundancy in the event the primary annular seal ring 50 is rendered ineffective. The secondary annular seal ring 60 may be formed of any material suitable for withstanding system operating temperatures.
Although illustrated and described above as a configuration having the plurality of plate members 52, the primary annular seal ring 50 and the secondary annular seal ring 60 connected to the housing 36, it is to be appreciated that one or all of these components may be integrally formed with, or operably coupled to, the stationary component 34. In one embodiment, the housing 36 is not present.
Referring now to
The secondary annular seal ring 60 includes a first end 68 and a second end 70, with the first end 68 in close proximity to the stationary component 34. As described in detail above, the first end 68 may be coupled to, or integrally formed with, the housing 36 or the stationary component 34, but in either event is integrally formed with the primary annular seal ring 50. The second end 70 is disposed in close proximity to the outer surface 32 of the rotor 18. In one embodiment (
As illustrated in the flow diagram of
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
