Method and apparatus for turbine interstage seal ring

A seal assembly for a gas turbine engine including a seal member and an interstage seal ring including an axially forward member coupled to a first radially inward surface of a first disk and an axially aft member coupled to a second radially inward surface of a second disk, wherein the seal ring is configured to move in an axial direction while the upstream and downstream arms are coupled to the first and second disk respectively.

BACKGROUND OF THE INVENTION

This invention relates generally to gas turbine engines, and more specifically to seal assemblies used with gas turbine engine rotor assemblies.

At least some known gas turbine engines include a core engine having, in serial flow arrangement, a fan assembly and a high pressure compressor, which compress airflow, entering the engine. A combustor ignites a fuel-air mixture, which is then channeled towards low and high pressure turbines that each include a plurality of rotor blades that extract rotational energy from airflow exiting the combustor. The high pressure compressor is coupled by a shaft to the high pressure turbine.

Generally, high pressure turbines include a first stage coupled to a second stage disk by a bolted connection. More specifically, the rotor shaft extends between a last stage of the multi-staged compressor and the web portions of the turbine first stage disk. The first and second stage turbine disks are isolated by a forward faceplate that is coupled to a forward face of the first stage disk, and an aft seal that is coupled to a rearward face of the second stage disk web. An interstage seal assembly extends between the first and second stage disks to facilitate sealing flow around a second stage turbine nozzle.

Commonly, interstage seal assemblies include an interstage seal and a separate blade retainer. The interstage seal is coupled to the first and second stage disks with a plurality of bolts. The blade retainer includes a split ring that is coupled to an axisymmetric hook assembly extending from the turbine stage disk. However, because the seal assemblies are complex, such interstage seal assemblies may be difficult to assemble. To facilitate reducing the assembly time and costs of such seal assemblies, other known interstage seal assemblies include an integrally-formed interstage seal and blade retainer. However, these seal assemblies while cheaper and easier to assemble, do not allow for inspection of the rotor sub-assemblies after assembly and prior to final location of the interstage seal.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a seal assembly for a gas turbine engine includes a seal member and an interstage seal ring including an axially forward member coupled to a first radially inward surface of a first disk and an axially aft member coupled to a second radially inward surface of a second disk, wherein the seal ring is configured to move in an axial direction while the upstream and downstream arms are coupled to the first and second disk respectively.

In another aspect, a method for assembling a seal assembly for a gas turbine engine rotor assembly includes coupling a seal ring to a first disk such that an upstream arm of the seal ring engages a first radially inward surface of the first disk and coupling the seal ring to a second disk such that a downstream arm of the seal ring engages a second radially inward surface of the second disk, wherein the seal ring is configured to move in an axial direction while the upstream and downstream arms are coupled to the first and second disk, respectively.

In a further aspect, a gas turbine engine includes a fan and combustor in serial flow communication and a rotor assembly comprising, a first disk, a second disk, and a seal assembly extending between the first disk and the second disk. The seal assembly includes a seal member and an interstage seal ring, the interstage seal ring includes, a forward member coupled to a radially inward surface of the first disk and an aft member coupled to a radially inward surface of the second disk wherein the seal ring is configured to move in an axial direction while the upstream and downstream arms are coupled to the first and second disk. respectively.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a schematic illustration of an exemplary gas turbine engine100. Engine100includes a compressor assembly102and a combustor assembly104. Engine100also includes a turbine108and a common compressor/turbine shaft110(sometimes referred to as a rotor110).

In operation, air flows through compressor assembly102such that compressed air is supplied to combustor assembly104. Fuel is channeled to a combustion region and/or zone (not shown) that is defined within combustor assembly104wherein the fuel is mixed with the air and ignited. Combustion gases generated are channeled to turbine108wherein gas stream thermal energy is converted to mechanical rotational energy. Turbine108is rotatably coupled to shaft110. It should also be appreciated that the term “fluid” as used herein includes any medium or material that flows, including, but not limited to, gas and air.

FIG. 2is an enlarged partial cross-sectional view of a portion of gas turbine engine100. Specifically,FIG. 2illustrates an enlarged partial cross-sectional view of turbine108. Turbine108includes a first stage disk202and a second stage disk204.

An interstage seal assembly215extends axially between turbine first and second disks202and204. More specifically, seal assembly215includes a seal member201, a seal ring205, and a retainer203. In one embodiment, seal ring205is generally cylindrical and includes a mid portion227, a first seal assembly surface228, and a second seal assembly surface229. However, in other embodiments, seal ring205may be an assembly of parts coupled together. Additionally, although in the exemplary embodiment the seal ring205comprises a cylindrical cross-section seal ring205is not limited to a cylindrical cross-section and for example, could have a catenary cross-section. Seal assembly surfaces228and229extend axially forward and aft, respectively from mid portion227to provide a contact area between seal ring205and first and second stage disks202and204. Seal assembly surfaces228and229are configured to create interference or rabbetted fits between first stage disk surface230and second disk surface231respectively. In various other embodiments, other fastener or attachment means may be used. In the exemplary embodiment the seal ring205includes a male rabbeted fit configured to engage a female rabbet on at least one of the first disk202and the second disk204. Mid portion227includes a plurality of seal teeth213which engage with seal member201.

FIG. 3is an enlarged view of a portion of the gas turbine engine shown inFIG. 1. More specifically,FIG. 3illustrates a positioning of seal ring205during assembly. During assembly, a spacer209is coupled to an aft edge232of first disk202. Then seal ring205is cooled to a substantially cooler temperature than first disk202. This temperature difference allows assembly surface228to slideably engage a radially interior surface230of first disk202. While still cooled, seal ring205is slid forward. This allows spacer209to be coupled to assembly surface233of second disk204. Next, seal ring205is again cooled, to a substantially lower temperature than both first disk202and second disk204and slid aft so that assembly surface231engages seal assembly surface229and seal ring205is axially restrained from further aft movement by surface211on second disk202. Finally, a retainer203may be coupled to second disk204at cutout240to restrain the axially forward movement of seal ring205. In the exemplary embodiment retainer203is a pin. In other embodiments retainer203could use any other means of attachment, such as, but not limited to bolts, wire retention, and bucket retention

FIG. 4is an enlarged partial view ofFIG. 2illustrating seal ring205after installation. After installation, seal ring205may be easily relocated to allow inspection of surfaces232and233. In another embodiment, seal ring205may be relocated to allow assembly and disassembly of parts that are inaccessible when seal ring205is in the installed position. First, retainer203, if used, is removed. Then seal ring205is cooled to a substantially lower temperature than first and second disks.202and204. After cooling, seal ring205may be slid forward to allow inspection of surfaces232and233.

Exemplary embodiments of rotor assemblies are described above in detail. The rotor assemblies are not limited to the specific embodiments described herein, but rather, components of each assembly may be utilized independently and separately from other components described herein. For example, each interstage seal assembly component can also be used in combination with other interstage seal assembly components and with other rotor assemblies.