The present disclosure relates to variable area vanes in gas turbine engines.
Gas turbine engines typically include a compressor section, a combustor section, and a turbine section. During operation, air is pressurized in the compressor section, and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.
Typically, both the compressor and turbine sections include alternating arrays of vanes and rotating blades that extend into a core airflow path of the gas turbine engine. For example, in the compressor section, compressor blades rotate to pull air into the compressor section for compression. The compressor vanes guide the airflow between different arrays (also called stages) of rotating blades and prepare the airflow for a downstream array of blades. Some compressor sections include variable area vanes, which include vanes that are moveable to vary the area or direction of the flow of the core airflow path between two stages of rotating blades. Movement of the variable area vanes is controlled to optimize the performance of the gas turbine engine during various operating conditions.
In one aspect of the invention, a vane stage includes a ringcase extending circumferentially about a center axis of the vane stage. The ringcase extends completely about the center axis to form a first ring. An inner shroud extends circumferentially about the center axis of the vane stage. The inner shroud extends completely about the center axis to form a second ring positioned radially within the ringcase relative the center axis. A plurality of stationary half vanes extend radially between the ringcase and the inner shroud, and are circumferentially spaced about the center axis. The plurality of stationary half vanes are integral with the ringcase and the inner shroud.
In another aspect of the invention, a vane stage includes a ringcase extending circumferentially about a center axis of the vane stage. The ringcase extends completely about the center axis to form a first non-segmented ring. An inner shroud extends circumferentially about the center axis of the vane stage. The inner shroud extends completely about the center axis to form a second non-segmented ring radially within the ringcase relative the center axis. A plurality of stationary half vanes extend radially between the ringcase and the inner shroud. The plurality of stationary half vanes are circumferentially spaced about the center axis and are integrally connected to the ringcase and the inner shroud. Each of the plurality of stationary half vanes includes both a leading edge extending radially from the inner shroud to the ringcase, and a groove extending radially from the inner shroud to the ringcase aft of the leading edge. A partial suction surface extends radially from the inner shroud to the ringcase and extends axially from the leading edge to the groove. A partial pressure surface extends radially from the inner shroud to the ringcase and extends axially from the leading edge to the groove opposite the partial suction surface. The groove is positioned between the partial suction surface and the partial pressure surface.
In another aspect of the invention, a vane stage includes a ringcase extending circumferentially about a center axis of the vane stage. The ringcase extends completely about the center axis to form a first non-segmented ring. An inner shroud extends circumferentially about the center axis of the vane stage. The inner shroud extends completely about the center axis to form a second non-segmented ring positioned radially within the ringcase relative the center axis. A plurality of stationary half vanes extend radially between the ringcase and the inner shroud, and are circumferentially spaced about the center axis. The plurality of stationary half vanes are integral with the ringcase and the inner shroud. A plurality of trunnion holes are formed in the ringcase aft of the plurality of stationary half vanes. Each trunnion hole of the plurality of trunnion holes is circumferentially aligned with one of the plurality of stationary half vanes and extends radially through the ringcase.
Persons of ordinary skill in the art will recognize that other aspects and embodiments of the present invention are possible in view of the entirety of the present disclosure, including the accompanying figures.
While the above-identified drawing figures set forth one or more embodiments of the invention, other embodiments are also contemplated. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features and components not specifically shown in the drawings. Like reference numerals identify similar structural elements.
The present disclosure provides a vane stage with an integral half vane structure with an outer ringcase, and inner shroud, and a plurality of stationary half vanes. Rotating variable half vanes are assembled onto the integral half vane structure aft of the stationary half vanes. Together, the stationary half vanes and the variable half vanes form an array of vanes where each vane has a fixed leading edge and an adjustable trailing edge that can be controlled to optimize the performance of a gas turbine engine during various operating conditions. Because the plurality of stationary half vanes, the outer ringcase and the inner shroud are integral, the position of stationary half vanes within integral half vane structure can be tightly controlled, which leads to tighter tolerances between the stationary half vanes and the variable half vanes. Tighter tolerances between the stationary half vanes and the variable vanes reduce flow irregularities across the vane stage. Making the ringcase, the inner shroud, and the plurality of stationary half vanes integral also reduces the number of parts and the weight of the vane stage when compared to traditional vane stages where vanes and shroud segments are fastened together into a vane pack.
The example gas turbine engine 20 generally includes low speed spool 30 and high speed spool 32 mounted for rotation about center axis CA of gas turbine engine 20 relative to engine static structure 36 via several bearing assemblies 38. It should be understood that various bearing assemblies 38 at various locations may alternatively or additionally be provided.
Low speed spool 30 generally includes inner shaft 40 that connects fan 42 and low pressure (or first) compressor 44 to low pressure (or first) turbine 46. Inner shaft 40 drives fan 42 through a speed change device, such as geared architecture 48, to drive fan 42 at a lower speed than low speed spool 30. High-speed spool 32 includes outer shaft 50 that interconnects high pressure (or second) compressor 52 and high pressure (or second) turbine 54. Inner shaft 40 and outer shaft 50 are concentric and rotate via bearing assemblies 38 about center axis CA.
Combustor 56 is arranged between high pressure compressor 52 and high pressure turbine 54. Mid-turbine frame 57 of engine static structure 36 can be arranged generally between high pressure turbine 54 and low pressure turbine 46. Mid-turbine frame 57 further supports bearing assemblies 38 in turbine section 28 as well as setting airflow entering the low pressure turbine 46. Mid-turbine frame 57 includes airfoils 59 which are in core flow path C. The air in core flow path C is compressed first by low pressure compressor 44 and then by high pressure compressor 52. Next, the air is mixed with fuel and ignited in combustor 56 to produce high speed exhaust gases that are then expanded through high pressure turbine 54, mid-turbine frame 58, and low pressure turbine 46. As discussed below with reference to
Ringcase 62 extends circumferentially about center axis CA. Ringcase 62 extends completely about center axis CA to form a first complete and non-segmented ring. Ringcase 62 extends axially from forward edge 88 to aft edge 90. Forward flange 68 is formed on forward edge 88 of ringcase 62 and extends radially outward from ringcase 62. Aft flange 70 is formed on aft edge 90 of ringcase 62 and extends radially outward from ringcase 62. Forward flange 68 and aft flange 70 are configured to allow ringcase 62 to be mounted between two axially-adjacent structures (not shown) in gas turbine engine 20. Inner shroud 64 also extends circumferentially about center axis CA. Similar to ringcase 62, inner shroud 64 extends completely about center axis CA to form a second complete and non-segmented ring. Inner shroud 64 is smaller in diameter than ringcase 62 and is positioned radially within ringcase 62 such that ringcase 62 and inner shroud 64 are concentric on central axis CA. Inner shroud 64 extends axially from forward edge 82 to aft edge 84. Mounting tabs 72 are formed on a radially inner surface of inner shroud 64 between forward edge 82 and aft edge 84. Mounting tabs 72 are circumferentially spaced from one another and extend radially inward from inner shroud 64. Mounting tabs 72 are provided to connect inner shroud 64 to forward and aft adjacent structures (such as aft ring 96 shown in
The plurality of stationary half vanes 66 extend radially between ringcase 62 and inner shroud 64 and connect ringcase 62 and inner shroud 64 together. Stationary half vanes 66 are spaced circumferentially about center axis CA. Stationary half vanes 66 are integral with ring case 62 and inner shroud 64. Integral half vane structure 60 can be formed by machining ringcase 62, inner shroud 64 and stationary half vanes 66 from a single piece of metal. Integral half vane structure 60 can also be made by first forming ringcase 62, welding a cylindrical plate (not shown) inside ringcase 62, and machining the cylindrical plate to form inner shroud 64 and stationary half vanes 66. Integral half vane structure 60 can also be made by separately forming ringcase 62, inner shroud 64, and stationary half vanes 66, and welding ringcase 62, inner shroud 64, and stationary half vanes 66 together. Integral half vane structure 60 can also be formed through additive manufacturing.
As shown best in
The plurality of outer trunnion holes 92 are formed in ringcase 62 aft of the plurality of stationary half vanes 66. Each of the outer trunnion holes 92 is circumferentially aligned with one of the plurality of stationary half vanes 66 and extends radially through ringcase 62 just aft of groove 76. A boss can be formed around each of the outer trunnion holes 92 to reinforce the circumference of the outer trunnion holes 92. The plurality of sockets 86 are formed on aft edge 84 of inner shroud 64. Each socket 86 of the plurality of sockets 86 is circumferentially aligned with one of the plurality of stationary half vanes 66. As shown best in
Each variable half vane 100 is assembled onto integral half vane structure 60 immediately aft of one of stationary half vanes 66. On each of variable half vanes 100, trailing edge 102 extends radially between inner shroud 64 and ringcase 62. Joining edge 104 is forward of trailing edge 102 and aft of groove 76. Joining edge 104 extends radially from inner shroud 64 to ringcase 62. As shown best in
On each of variable half vanes 100, first trunnion 106 extends radially outward proximate joining edge 104 and into one of outer trunnion holes 92 on ringcase 62. Trunnion nut 112 is fastened to first trunnion 106 to fasten variable half vane 100 to ringcase 62. Second trunnion 108 extends radially inward proximate joining edge 104 and is positioned aft of aft edge 84 (shown in
Aft ring 96 forms an inner diameter flow surface aft and downstream of stationary half vanes 66. Aft ring 96 also forms the inner diameter flow surface under at least a portion of variable half vanes 100. As shown in
In the embodiment of
In view of the foregoing description, it will be recognized that the present disclosure provides numerous advantages and benefits. For example, the present disclosure provides integral half vane structure 60 with ringcase 62, inner shroud 64, and a plurality of stationary half vanes 66. Stationary half vanes 66 are integral with ring case 62 and inner shroud 64. Because stationary half vanes 66 are integral with ring case 62 and inner shroud 64, the position of each stationary half vane 66 can be tightly controlled during manufacturing and does not shift or vary like prior art vane assemblies. Furthermore, by making stationary half vanes 66 integral with ringcase 62 and inner shroud 64, fewer parts, fasteners, and overall mass are required to assemble a vane stage that incorporates integral half vane structure 60 than prior art vane assemblies.
The following are non-exclusive descriptions of possible embodiments of the present invention.
In one embodiment, a vane stage includes a ringcase extending circumferentially about a center axis of the vane stage. The ringcase extends completely about the center axis to form a first ring. An inner shroud extends circumferentially about the center axis of the vane stage. The inner shroud extends completely about the center axis to form a second ring positioned radially within the ringcase relative the center axis. A plurality of stationary half vanes extend radially between the ringcase and the inner shroud, and are circumferentially spaced about the center axis. The plurality of stationary half vanes are integral with the ringcase and the inner shroud.
The vane stage of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
each of the plurality of stationary half vanes comprises: a leading edge extending radially from the inner shroud to the ringcase; a concave groove extending radially from the inner shroud to the ringcase and aft of the leading edge; a partial suction surface extending radially from the inner shroud to the ringcase and extending axially from the leading edge to the concave groove; and a partial pressure surface extending radially from the inner shroud to the ringcase and extending axially from the leading edge to the concave groove opposite the partial suction surface, and wherein the concave groove is positioned between the partial suction surface and the partial pressure surface;
each of the plurality of stationary half vanes further comprises: a first undercut formed between the concave groove and the inner shroud; and a second undercut formed between the concave groove and the ringcase;
a plurality of trunnion holes formed in the ringcase, wherein each trunnion hole of the plurality of trunnion holes is circumferentially aligned with one of the plurality of stationary half vanes and extends radially through the ringcase aft of the concave groove;
a plurality of sockets formed on an aft edge of the inner shroud, wherein each socket of the plurality of sockets is circumferentially aligned with one of the plurality of stationary half vanes;
a plurality of variable half vanes, wherein each of the plurality of variable half vanes comprises: a trailing edge extending radially between the inner shroud and the ringcase; a convex edge extending radially from the inner shroud to the ringcase, wherein the convex edge is forward of the trailing edge and configured to mate with the concave groove of one of the plurality of stationary half vanes; a first trunnion extending radially from the convex edge into one of the plurality of trunnion holes; a second trunnion extending radially from the convex edge opposite the first trunnion, wherein the second trunnion is aft of the aft edge of the inner shroud; and a button formed on the second trunnion, wherein a portion of the button is received by one of the plurality of sockets;
the ringcase is axially longer than the inner shroud and increases in diameter aft of the plurality of stationary half vanes;
the ringcase comprises a plurality of ribs formed on an outer surface of the ringcase aft of the plurality of stationary half vanes;
each of the plurality of ribs increases in radial thickness in an aft direction;
the plurality of ribs comprises: an axial rib extending parallel to the center axis; a first angled rib intersecting the axial rib at a node; and a second angled rib intersecting the axial rib and the first angled rib at the node; and/or
the node is not centered on the axial rib.
In another embodiment, a vane stage includes a ringcase extending circumferentially about a center axis of the vane stage. The ringcase extends completely about the center axis to form a first non-segmented ring. An inner shroud extends circumferentially about the center axis of the vane stage. The inner shroud extends completely about the center axis to form a second non-segmented ring radially within the ringcase relative the center axis. A plurality of stationary half vanes extend radially between the ringcase and the inner shroud. The plurality of stationary half vanes are circumferentially spaced about the center axis and are integrally connected to the ringcase and the inner shroud. Each of the plurality of stationary half vanes includes both a leading edge extending radially from the inner shroud to the ringcase, and a groove extending radially from the inner shroud to the ringcase aft of the leading edge. A partial suction surface extends radially from the inner shroud to the ringcase and extends axially from the leading edge to the groove. A partial pressure surface extends radially from the inner shroud to the ringcase and extends axially from the leading edge to the groove opposite the partial suction surface. The groove is positioned between the partial suction surface and the partial pressure surface.
The vane stage of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
the groove of each of the plurality of stationary half vanes is a concave groove with a surface that curves axially forward into the respective stationary half vane;
a plurality of trunnion holes formed in the ringcase, wherein each trunnion hole of the plurality of trunnion holes is circumferentially aligned with one of the plurality of stationary half vanes and extends radially through the ringcase aft of the groove;
a plurality of sockets formed on an aft edge of the inner shroud, wherein each socket of the plurality of sockets is circumferentially aligned with one of the plurality of stationary half vanes;
a plurality of variable half vanes, wherein each of the plurality of variable half vanes comprises: a trailing edge extending radially between the inner shroud and the ringcase; a joining edge extending radially from the inner shroud to the ringcase, wherein the joining edge is forward of the trailing edge and configured to mate with the groove of one of the plurality of stationary half vanes; a first trunnion extending radially from the joining edge into one of the plurality of trunnion holes; a second trunnion extending radially from the joining edge opposite the first trunnion, wherein the second trunnion is aft of the aft edge of the inner shroud; and a button formed on the second trunnion, wherein a portion of the button is received by one of the plurality of sockets; and/or
the ringcase is axially longer than the inner shroud.
In another embodiment, a vane stage includes a ringcase extending circumferentially about a center axis of the vane stage. The ringcase extends completely about the center axis to form a first non-segmented ring. An inner shroud extends circumferentially about the center axis of the vane stage. The inner shroud extends completely about the center axis to form a second non-segmented ring positioned radially within the ringcase relative the center axis. A plurality of stationary half vanes extend radially between the ringcase and the inner shroud, and are circumferentially spaced about the center axis. The plurality of stationary half vanes are integral with the ringcase and the inner shroud. A plurality of trunnion holes are formed in the ringcase aft of the plurality of stationary half vanes. Each trunnion hole of the plurality of trunnion holes is circumferentially aligned with one of the plurality of stationary half vanes and extends radially through the ringcase.
The vane stage of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
each of the plurality of stationary half vanes comprises: a leading edge extending radially from the inner shroud to the ringcase; a groove extending radially from the inner shroud to the ringcase and aft of the leading edge, wherein the groove has a concave cross-sectional profile; a partial suction surface extending radially from the inner shroud to the ringcase and extending axially from the leading edge to the groove; and a partial pressure surface extending radially from the inner shroud to the ringcase and extending axially from the leading edge to the groove opposite the partial suction surface, and wherein the groove is positioned between the partial suction surface and the partial pressure surface; and/or
a plurality of variable half vanes, wherein each of the plurality of variable half vanes comprises: a trailing edge extending radially between the inner shroud and the ringcase; a joining edge extending radially from the inner shroud to the ringcase, wherein the joining edge is forward of the trailing edge and configured to mate with the groove of one of the plurality of stationary half vanes; a first trunnion extending radially from the joining edge into one of the plurality of trunnion holes; a second trunnion extending radially from the convex edge opposite the first trunnion, wherein the second trunnion is aft of an aft edge of the inner shroud.
Any relative terms or terms of degree used herein, such as “substantially”, “essentially”, “generally”, “approximately”, and the like, should be interpreted in accordance with and subject to any applicable definitions or limits expressly stated herein. In all instances, any relative terms or terms of degree used herein should be interpreted to broadly encompass any relevant disclosed embodiments as well as such ranges or variations as would be understood by a person of ordinary skill in the art in view of the entirety of the present disclosure, such as to encompass ordinary manufacturing tolerance variations, incidental alignment variations, transitory vibrations and sway movements, temporary alignment or shape variations induced by operational conditions, and the like.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. For example, while
This invention was made with Government support awarded by the United States. The Government has certain rights in this invention.
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