The disclosure relates generally to gas turbine engines, and more particularly to vane assemblies in gas turbine engines.
Vane assemblies are usually provided in gas turbine engines downstream of a fan and/or may be part of a low pressure compressor. Vane assemblies may be used to re-direct an air stream such as, for example, reducing a swirl movement of an air stream in a compressor of a gas turbine engine.
Vane assemblies may comprise radially inner and/or outer shrouds or supports to which vanes are secured. The vanes may be secured to inner and/or outer shrouds via resilient grommets that provide both a seal between the vanes and the shroud(s) and damping of vibrations. Grommets usually need to be molded to fit the exact shape of the vanes either before or during installation. Also, in order to maintain an adequate sealing function, such grommets usually require a radial pre-load of the vanes to be maintained. Accordingly, the use of such grommets can render the installation and assembly of such vane assemblies relatively complex and labor intensive.
Improvement in vane assemblies is therefore desirable.
There is provided, in accordance with one aspect of the present disclosure, a vane assembly for use in a gas turbine engine, the assembly comprising: at least one shroud having at least one vane-receiving portion; at least one vane having at least one end portion received in the at least one vane-receiving portion of the at least one shroud; and at least one sealing member having an uncompressed cross-section that is substantially circular, the at least one sealing member being disposed between and in contact with the at least one end portion of the at least one vane and the at least one vane-receiving portion of the at least one shroud.
There is also provided, in accordance with another aspect, a gas turbine engine comprising: at least one inlet, compressor, combustor and turbine section in serial flow communication; and at least one vane assembly disposed downstream from the at least one inlet, the at least one vane assembly including: at least one radially inner shroud having at least one inner vane-receiving portion; at least one radially outer shroud having at least one outer vane-receiving portion; at least one vane having at least one inner end portion received in the at least one inner vane-receiving portion of the inner shroud and at least one outer end portion received in the outer vane-receiving portion of the at least one outer shroud; and at least one sealing member having an uncompressed cross-section that is substantially circular, the at least one sealing member being disposed between the at least one vane and at least one of the at least one inner vane-receiving portion of the at least one inner shroud and the at least one outer vane-receiving portion of the at least one outer shroud.
There is further provided, in accordance with another aspect, a method for assembling a vane assembly for use in a gas turbine engine wherein the vane assembly comprises at least one vane and at least one shroud, the method comprising: installing at least one sealing member having an uncompressed cross-section that is substantially circular on one of: at least one end portion of the at least one vane; and at least one vane-receiving portion on the at least one shroud; and installing the at least one end portion of the at least one vane in the at least one vane-receiving portion to establish contact of the at least one sealing member with the at least one end portion of the at least one vane and the at least one vane-receiving portion.
Further details of these and other aspects of the subject matter of this application will be apparent from the detailed description and drawings included below.
Reference is now made to the accompanying drawings, in which:
Aspects of various embodiments are described through reference to the drawings.
Outer vane-receiving portion(s) 26 of outer shroud(s) 24 may comprise at least one opening configured to receive outer end portion(s) 36 of vane(s) 32. Accordingly, outer end portion(s) 36 of vane(s) 32 may extend through outer shroud(s) 24. At least one sealing member(s) 40 may be provided between outer end portion(s) 36 of vane(s) 32 and outer vane-receiving portion(s) 26 of outer shroud(s) 24 to hinder or substantially prevent air from leaving bypass duct 22 through outer vane-receiving portion(s) 26. Sealing member(s) 40 may also provide vibration damping and support for vane(s) 32. Sealing member(s) 40 may be positioned radially away (e.g. outward) from bypass duct(s) 22 in order to be out of the stream of air (e.g. gas path) flowing through bypass duct(s) 22. Accordingly, sealing member(s) 40 may not be directly exposed to rapidly flowing air which could potentially cause lifting, deterioration, erosion and/or other types of wear or performance degradation of sealing member(s) 40. Sealing member(s) 40 may be in the form of a compressible packing having an uncompressed cross-section that is substantially circular (e.g. O-shaped). Sealing member(s) 40 may have an uncompressed cross-section that is substantially uniform along a substantially entire sealing length. For example, sealing member(s) 40 may comprise one or more conventional or other types of pre-formed packings such as o-rings. Sealing member(s) 40 may be made from a material that is compressible (e.g. deformable), resilient and of appropriate stiffness to provide some degree of sealing between vane(s) 32 and outer shroud(s) 24 and also provide some vibration damping and support for vane(s) 32. Sealing member(s) 40 may also be made from a material capable of reasonably withstanding the environmental conditions in the applicable region(s) of engine 10. Sealing member(s) 40 may be made from any suitable material(s) conventionally used to produce o-rings and suitable for use in gas turbine applications. For example, sealing member(s) 40 may be made from an electrically insulating material. Sealing member(s) 40 may be made from materials such as, for example, rubber-like material(s), elastomeric material(s), polyurethane, ethylene propylene rubber, nitrile butadiene rubber, silicone rubber, and elastomeric synthetic polymer or copolymer material(s).
Outer end portion(s) 36 of vane(s) 32 may comprise groove(s) 42 for receiving at least a portion of sealing member(s) 40 and outer vane-receiving portion(s) 26 may comprise cooperating contact surface(s) 44. Groove(s) 42 may extend completely around (i.e. peripherally) outer end portion(s) 36 of vane(s) 32. Accordingly, sealing member(s) 40 may comprise o-ring(s) installed in groove(s) 42. Sealing member(s) 40 may be disposed between and configured to contact outer end portion(s) 36 of vane(s) 32 and outer vane-receiving portion(s) 26 of outer shroud(s) 24. For example, a clearance provided between outer end portion(s) 36 of vane(s) 32 and outer vane-receiving portion(s) 26 and groove(s) 42 may be configured so that sealing member(s) 40 make contact with bottom surface(s) 46 of groove(s) 42 and also contact surface(s) 44 of outer vane-receiving portion(s) 26. The clearance between outer end portion(s) 36 of vane(s) 32 and outer vane-receiving portion(s) 26 and groove(s) 42 may also be configured so that sealing member(s) 40 is/are compressed (i.e. deformed) by a desired amount when installed between bottom surface(s) 46 of groove(s) 42 and contact surface(s) 44 of outer vane-receiving portion(s) 26 in order to maintain a desired sealing performance. Accordingly, a radially inward biasing force may not be necessary to maintain a desired sealing performance.
Strap(s) 47 may extend circumferentially about centerline CL of engine 10 and serve to secure vane(s) 32 in position. For example, strap(s) 47 may provide radial support to restrain radial movement of vane(s) 32. Strap(s) 47 may also be configured to exert a radially inward biasing force on vane(s) 32 in order to keep vane(s) 32 properly seated against back wall(s) 48 of inner vane-receiving potion(s) 30 of inner shroud(s) 28. However, any radially inward biasing force provided by strap(s) 47 may not be required to maintain the sealing function of sealing member(s) 40. Accordingly, installation of vane assembly(ies) 20 and strap 47 may be simplified since radial pre-loading of vane(s) 32 may not be necessary to maintain proper sealing function of sealing member(s) 40.
Inner vane-receiving portion(s) 30 of inner shroud(s) 28 may comprise at least one opening configured to receive inner end portion(s) 38 of vane(s) 32. Inner vane-receiving portion(s) 30 of inner shroud(s) 28 may be closed and may be in the form of a recess having back wall(s) 48. Back wall(s) 48 may be integrally formed with inner shroud(s) 28 or may comprise a separate member attached to inner shroud(s) 28. Accordingly, inner end portion(s) 38 of vane(s) 32 may be received in inner vane-receiving portion(s) 30 of inner shroud(s) 28. As described above in relation to outer vane-receiving portion(s) 26, another/other sealing member(s) 40 may be provided between inner end portion(s) 38 of vane(s) 32 and inner vane-receiving portion(s) 30 of inner shroud(s) 24 and be configured in a similar manner or practically identically to the arrangement of outer end portion(s) 36 of vane(s) 32 and outer vane-receiving portion(s) 26. Hence, inner end portion(s) 38 of vane(s) 32 may also comprise groove(s) 42 in which at least a portion of sealing member(s) 40 may be received and inner vane-receiving portion(s) 30 may also comprise contact surface(s) 44 against which sealing member(s) 40 may be in contact and compressed. Groove(s) 42 may be configured (e.g. suitable length, width and depth) to receive at least a portion of sealing member(s) 40. Another portion of sealing member(s) 40 not received in (i.e. protruding from) groove(s) 42 may serve to contact with contact surface(s) 44. Sealing member(s) 40 between inner end portion(s) 38 and inner vane-receiving portion(s) 30 may serve to reduce losses by hindering or substantially preventing air in bypass duct 22 from flowing through a clearance between inner end portion(s) 38 and inner vane-receiving portion(s) 30. Sealing member(s) 40 between inner end portion(s) 38 and inner vane-receiving portion(s) 30 may also serve to damp vibrations. As described above, the clearance between inner end portion(s) 38 of vane(s) 32 and inner vane-receiving portion(s) 30 and groove(s) 42 may also be configured so that sealing member(s) 40 is compressed (i.e. deformed) by a desired amount when installed between bottom surface(s) 46 of groove(s) 42 and contact surface(s) 44 of inner vane-receiving portion(s) 26 in order to maintain a desired sealing, damping and/or support function(s).
Vane assembly(ies) 200 may comprise outer shroud(s) 240A, 240B including outer vane-receiving portion(s) 260; inner shroud(s) 280A, 280B including inner vane-receiving portion(s) 300; and vane(s) 320. Outer shroud(s) 240A, 240B may, for example, include a radially outer casing of compressor 14. Outer shroud(s) 240A, 240B may comprise multiple pieces. For example, outer shroud(s) 240A, 240B may comprise forward outer shroud portion(s) 240A and aft outer shroud portion(s) 240B. Forward outer shroud portion(s) 240A and aft outer shroud portion(s) 240B may each have an annular configuration and be disposed about (e.g. coaxial to) centerline CL of engine 10. Forward outer shroud portion(s) 240A and aft outer shroud portion(s) 240B may be secured to each other at outer shroud interface(s) 240C. At least one of forward outer shroud portion(s) 240A and aft outer shroud portion(s) 240B may comprise groove(s) 420 for receiving at least a portion of sealing member(s) 400. Groove(s) 420 may extend circumferentially around forward outer shroud portion(s) 240A and/or aft outer shroud portion(s) 240B about centerline CL of engine 10.
Inner shroud(s) 280A, 280B may, for example, include a radially inner casing of compressor 14. Similar to outer shroud(s) 240A, 240B, inner shroud(s) 280A, 280B may also be provided in multiple pieces. For example, inner shroud(s) 280A, 280B may comprise forward inner shroud portion(s) 280A and aft inner shroud portion(s) 280B. Forward inner shroud portion(s) 280A and aft inner shroud portion(s) 280B may also each have an annular configuration and also be disposed about (e.g. coaxial to) centerline CL of engine 10. Forward inner shroud portion(s) 280A and aft inner shroud portion(s) 280B may be secured to each other at inner shroud interface(s) 280C. At least one of forward inner shroud portion(s) 280A and aft inner shroud portion(s) 280B may comprise groove(s) 420 for receiving sealing member(s) 400. Groove(s) 420 may extend circumferentially around forward inner shroud portion(s) 280A and/or aft outer shroud portion(s) 280B. Groove(s) 420 may extend circumferentially around forward outer shroud portion(s) 280A and/or aft outer shroud portion(s) 280B about centerline CL of engine 10.
Vane(s) 320 may include airfoil-shaped body(ies) 340, outer end portion(s) 360 and inner end portion(s) 380. Vane(s) 320 may be stationary and may be used to re-direct a stream of air through compressor 14. Outer end portion(s) 360 and/or inner end portion(s) 380 may comprise contact surface(s) 440. Contact surface(s) 440 may contact sealing member(s) 400. Contact surface(s) 440 and groove(s) 420 may cooperate together to compress sealing member(s) 400 by a desired amount to provide a desired sealing, vibration damping and/or support function(s) between inner/outer shrouds 240A, 240B, 280A, 280B and vane(s) 320. Sealing member(s) 400 between outer end portion(s) 360 and outer vane-receiving portion(s) 260 and/or between inner end portion(s) 380 and inner vane-receiving portion(s) 300 may serve to reduces losses by hindering or substantially preventing air in compressor 14 from flowing through a clearance provided between outer end portion(s) 360 and outer vane-receiving portion(s) 260 and/or between inner end portion(s) 380 and inner vane-receiving portion(s) 300.
Sealing member(s) 400 may be of similar or substantially identical construction as sealing member(s) 40 and may also be made from suitable materials as listed above in regards to sealing member(s) 40. For example, sealing member(s) 40, 400 may have a substantially circular and uniform uncompressed cross-section and may comprise one or more o-rings of suitable dimensions (e.g. cross-sectional diameter and outer diameter/length) to be installed in respective groove(s) 42, 420.
The use of sealing member(s) 40, 400 of a substantially circular cross-section between vane(s) 32, 320 and shroud(s) 24, 240A, 240B, 28, 280A, 280B may facilitate assembly of vane assembly(ies) 20, 200. In particular, the assembly of vane assembly(ies) 20, 200 may be relatively more straightforward and quicker. As mentioned above, radial pre-loading of vanes may not be required for the purpose of maintaining a proper sealing function of sealing member(s) 40, 400. For example a method for assembling vane assembly(ies) 20, 200 may comprise: (1) installing sealing member(s) 40, 400 having an uncompressed cross-section that is substantially circular on one of: at least one of end portion(s) 36, 360, 38, 380 of at least one of vane(s) 32, 320; and at least one of vane-receiving portion(s) 26, 260, 30, 300 of at least one of shroud(s) 24, 240A, 240B, 28, 280A, 280B; and (2) installing at least one of end portion(s) 36, 360, 38, 380 of the at least one vane(s) 32, 320 in the at least one vane-receiving portion(s) 26, 260, 30, 300 to establish contact of sealing member(s) 40, 400 with at least one of end portion(s) 36, 360, 38, 380 of the at least one of vane(s) 32, 320 and the at least one vane-receiving portion(s) 26, 260, 30, 300.
Vane(s) 32, 320 could be made by various manufacturing processes including forging, die casting and/or injection molding. For example, vane(s) 32, 320 could be made from materials including an aluminum-based alloy or a polymer material such as polyether ether ketone (PEEK) or Nylon. Vane(s) 32, 320 may, for example, comprise carbon fiber. A structural coating such as a nano-coating may be applied to vane(s) 32, 320 to obtain desired properties (e.g. stiffness and strength) and performance characteristics of vane(s) 32, 320. Groove(s) 42 on vane(s) 32 may be forged or formed simultaneously with the molding of vane(s) 32. Alternatively, groove(s) 42 on vane(s) 32 could be formed (e.g. machined) subsequently to the forming of airfoil-shaped body(ies) 34 of vane(s) 32. Similarly, groove(s) 420 on shroud(s) 240A, 240B, 280A, 280B could be formed by forging or casting during the manufacture of shroud(s) 240A, 240B, 280A, 280B or formed subsequently by machining for example. Shroud(s) 24, 240A, 240B, 28, 280A, 280B may, for example, comprise an aluminum-based alloy.
As mentioned above, sealing member(s) 40, 400 may comprise material(s) that is/are substantially electrically insulating and therefore may allow for dissimilar materials having different electrode potentials to be used for vane(s) 32, 320 and shroud(s) 24, 240A, 240B, 28, 280A, 280B. For example, sealing member(s) 40, 400 may also serve to electrically isolate vane(s) 32, 320 from shroud(s) 24, 240A, 240B, 28, 280A, 280B and prevent risks of galvanic corrosion between vane(s) 32, 320 and shroud(s) 24, 240A, 240B, 28, 280A, 280B.
During use, vane(s) 32, 320 may serve to re-direct air flowing through bypass duct(s) 22 and/or compressor 14. Sealing member(s) 40, 400 disposed between vane(s) 32, 320 and shroud(s) 24, 240A, 240B, 28, 280A, 280B may serve to reduce losses by hindering or substantially preventing air from flowing through a clearance between vane(s) 32, 320 and shroud(s) 24, 240A, 240B, 28, 280A, 280B. Sealing member(s) 40, 400 may also serve to damp vibrations and provide support of vane(s) 32, 320. As described above, sealing member(s) 40, 400 may be compressed (i.e. deformed) by a desired amount when installed between vane(s) 32, 320 and shroud(s) 24, 240A, 240B, 28, 280A, 280B in order to maintain desired sealing, damping and/or support function(s).
The term “at least one” as used herein is intended to mean “one or more than one” of the identified elements.
The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. For example, the specific configurations of vane assemblies 20 and 200 are not limited respectively for use in bypass duct(s) 22 and compressor 14. It is also intended that aspects from vane assembly(ies) 20 and vane assembly(ies) 200 may be combined (i.e. interchanged). For example, the above description is intended to also include vane assemblies that comprise outer end portion(s) 36, 360 and outer vane-receiving portion(s) 26, 260 as configured in vane assembly(ies) 20 combined with inner end portion(s) 38, 380 and inner vane-receiving portion(s) 30, 300 as configured in vane assembly(ies) 200, or vice versa.
Still other modifications which fall within the scope of the present invention will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.