Patent Application
20100247294
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.
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.
In operation, air flows through compressor assembly 102 such that compressed air is supplied to combustor assembly 104. Fuel is channeled to a combustion region and/or zone (not shown) that is defined within combustor assembly 104 wherein the fuel is mixed with the air and ignited. Combustion gases generated are channeled to turbine 108 wherein gas stream thermal energy is converted to mechanical rotational energy. Turbine 108 is rotatably coupled to shaft 110. 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.
An interstage seal assembly 215 extends axially between turbine first and second disks 202 and 204. More specifically, seal assembly 215 includes a seal member 201, a seal ring 205, and a retainer 203. In one embodiment, seal ring 205 is generally cylindrical and includes a mid portion 227, a first seal assembly surface 228, and a second seal assembly surface 229. However, in other embodiments, seal ring 205 may be an assembly of parts coupled together. Additionally, although in the exemplary embodiment the seal ring 205 comprises a cylindrical cross-section seal ring 205 is not limited to a cylindrical cross-section and for example, could have a catenary cross-section. Seal assembly surfaces 228 and 229 extend axially forward and aft, respectively from mid portion 227 to provide a contact area between seal ring 205 and first and second stage disks 202 and 204. Seal assembly surfaces 228 and 229 are configured to create interference or rabbetted fits between first stage disk surface 230 and second disk surface 231 respectively. In various other embodiments, other fastener or attachment means may be used. In the exemplary embodiment the seal ring 205 includes a male rabbeted fit configured to engage a female rabbet on at least one of the first disk 202 and the second disk 204. Mid portion 227 includes a plurality of seal teeth 213 which engage with seal member 201.
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.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
