Abstract:
One embodiment of the present invention is a unique variable geometry vane system. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and turbomachinery variable geometry vane systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims benefit of U.S. Provisional Patent Application No. 61/428,631, filed Dec. 30, 2010, entitled Variable Geometry Vane System For Gas Turbine Engines, which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to turbomachinery, and more particularly, to a variable geometry vane system for gas turbine engines. 
     BACKGROUND 
     Variable geometry vane systems for gas turbine engines and other turbomachinery systems remain an area of interest. Some existing systems have various shortcomings, drawbacks, and disadvantages relative to certain applications. Accordingly, there remains a need for further contributions in this area of technology. 
     SUMMARY 
     One embodiment of the present invention is a unique variable geometry vane system. Another embodiment is a unique gas turbine engine. Other embodiments include apparatuses, systems, devices, hardware, methods, and combinations for gas turbine engines and turbomachinery variable geometry vane systems. Further embodiments, forms, features, aspects, benefits, and advantages of the present application will become apparent from the description and figures provided herewith. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein: 
         FIG. 1  schematically illustrates some aspects of a non-limiting example of a gas turbine engine in accordance with an embodiment of the present invention. 
         FIG. 2A  illustrates a perspective view of some aspects of a non-limiting example of a portion of a variable geometry vane system in accordance with an embodiment of the present invention, showing one variable geometry vane of a plurality of variable geometry vanes of the variable geometry vane system. 
         FIG. 2B  is an exploded view illustrating some aspects of a non-limiting example of the variable geometry vane system of  FIG. 2A  in accordance with an embodiment of the present invention. 
         FIG. 3  is a perspective view of some aspects of a non-limiting example of the variable geometry vane system of  FIG. 2A  in accordance with an embodiment of the present invention. 
         FIG. 4  is a perspective view of some aspects of a non-limiting example of the variable geometry vane system of  FIG. 2A  in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nonetheless be understood that no limitation of the scope of the invention is intended by the illustration and description of certain embodiments of the invention. In addition, any alterations and/or modifications of the illustrated and/or described embodiment(s) are contemplated as being within the scope of the present invention. Further, any other applications of the principles of the invention, as illustrated and/or described herein, as would normally occur to one skilled in the art to which the invention pertains, are contemplated as being within the scope of the present invention. 
     Referring to the drawings, and in particular  FIG. 1 , there are illustrated some aspects of a non-limiting example of a gas turbine engine  20  in accordance with an embodiment of the present invention. In one form, engine  20  is a propulsion engine, e.g., an aircraft propulsion engine. In other embodiments, engine  20  may be any other type of gas turbine engine, e.g., a marine gas turbine engine, an industrial gas turbine engine, or any aero, aero-derivative or non-aero gas turbine engine. In one form, engine  20  is a two spool engine having a high pressure (HP) spool  24  and a low pressure (LP) spool  26 . In other embodiments, engine  20  may include three or more spools, e.g., may include an intermediate pressure (IP) spool and/or other spools. In one form, engine  20  is a turbofan engine, wherein LP spool  26  is operative to drive a propulsor  28  in the form of a turbofan (fan) system, which may be referred to as a turbofan, a fan or a fan system. In other embodiments, engine  20  may be a turboprop engine, wherein LP spool  26  powers a propulsor  28  in the form of a propeller system (not shown), e.g., via a reduction gearbox (not shown). In yet other embodiments, LP spool  26  powers a propulsor  28  in the form of a propfan. In still other embodiments, propulsor  28  may take other forms, such as one or more helicopter rotors or tilt-wing aircraft rotors. 
     In one form, engine  20  includes, in addition to fan  28 , a bypass duct  30 , a compressor  32 , a diffuser  34 , a combustor  36 , a high pressure (HP) turbine  38 , a low pressure (LP) turbine  40 , a nozzle  42 A, a nozzle  42 B, and a tailcone  46 , which are generally disposed about and/or rotate about an engine centerline  49 . In other embodiments, there may be, for example, an intermediate pressure spool having an intermediate pressure turbine. In one form, engine centerline  49  is the axis of rotation of fan  28 , compressor  32 , turbine  38  and turbine  40 . In other embodiments, one or more of fan  28 , compressor  32 , turbine  38  and turbine  40  may rotate about a different axis of rotation. 
     In the depicted embodiment, engine  20  core flow is discharged through nozzle  42 A, and the bypass flow is discharged through nozzle  42 B. In other embodiments, other nozzle arrangements may be employed, e.g., a common nozzle for core and bypass flow; a nozzle for core flow, but no nozzle for bypass flow; or another nozzle arrangement. Bypass duct  30  and compressor  32  are in fluid communication with fan  28 . Nozzle  42 B is in fluid communication with bypass duct  30 . Diffuser  34  is in fluid communication with compressor  32 . Combustor  36  is fluidly disposed between compressor  32  and turbine  38 . Turbine  40  is fluidly disposed between compressor  32  and turbine  38 . Turbine  40  is fluidly disposed between turbine  38  and nozzle  42 A. In one form, combustor  36  includes a combustion liner that contains a continuous combustion process. In other embodiments, combustor  36  may take other forms, and may be, for example, a wave rotor combustion system, a rotary valve combustion system, a pulse detonation combustion system or a slinger combustion system, and may employ deflagration and/or detonation combustion processes. 
     Fan system  28  includes a fan rotor system  48  driven by LP spool  26 . In various embodiments, fan rotor system  48  may include one or more rotors (not shown) that are powered by turbine  40 . In various embodiments, fan  28  may include one or more fan vane stages (not shown in  FIG. 1 ) that cooperate with fan blades (not shown) of fan rotor system  48  to compress air and to generate a thrust-producing flow. Bypass duct  30  is operative to transmit a bypass flow generated by fan  28  around the core of engine  20 . Compressor  32  includes a compressor rotor system  50 . In various embodiments, compressor rotor system  50  includes one or more rotors (not shown) that are powered by turbine  38 . Compressor  32  also includes a plurality of compressor vane stages (not shown in  FIG. 1 ) that cooperate with compressor blades (not shown) of compressor rotor system  50  to compress air. In various embodiments, the compressor vane stages may include a compressor discharge vane stage and/or a diffuser vane stage. 
     Turbine  38  includes a turbine rotor system  52 . In various embodiments, turbine rotor system  52  includes one or more rotors (not shown) operative to drive compressor rotor system  50 . Turbine  38  also includes a plurality of turbine vane stages (not shown in  FIG. 1 ) that cooperate with turbine blades (not shown) of turbine rotor system  52  to extract power from the hot gases discharged by combustor  36 . Turbine rotor system  52  is drivingly coupled to compressor rotor system  50  via a shafting system  54 . Turbine  40  includes a turbine rotor system  56 . In various embodiments, turbine rotor system  56  includes one or more rotors (not shown) operative to drive fan rotor system  48 . Turbine  40  also includes a plurality of turbine vane stages (not shown in  FIG. 1 ) that cooperate with turbine blades (not shown) of turbine rotor system  56  to extract power from the hot gases discharged by turbine  38 . Turbine rotor system  56  is drivingly coupled to fan rotor system  48  via a shafting system  58 . In various embodiments, shafting systems  54  and  58  include a plurality of shafts that may rotate at the same or different speeds and directions for driving fan rotor system  48  rotor(s) and compressor rotor system  50  rotor(s). In some embodiments, only a single shaft may be employed in one or both of shafting systems  54  and  58 . Turbine  40  is operative to discharge the engine  20  core flow to nozzle  42 A. 
     During normal operation of gas turbine engine  20 , air is drawn into the inlet of fan  28  and pressurized by fan rotor  48 . Some of the air pressurized by fan rotor  48  is directed into compressor  32  as core flow, and some of the pressurized air is directed into bypass duct  30  as bypass flow. Compressor  32  further pressurizes the portion of the air received therein from fan  28 , which is then discharged into diffuser  34 . Diffuser  34  reduces the velocity of the pressurized air, and directs the diffused core airflow into combustor  36 . Fuel is mixed with the pressurized air in combustor  36 , which is then combusted. The hot gases exiting combustor  36  are directed into turbines  38  and  40 , which extract energy in the form of mechanical shaft power to drive compressor  32  and fan  28  via respective shafting systems  54  and  58 . The hot gases exiting turbine  40  are discharged through nozzle system  42 A, and provide a component of the thrust output by engine  20 . 
     Referring now to  FIGS. 2A and 2B , some aspects of a non-limiting example of a variable geometry vane system  60  in accordance with an embodiment of the present invention is illustrated. In one form, variable geometry vane system  60  is a variable geometry compressor vane system. In other embodiments, variable geometry vane system  60  may be a variable geometry fan vane system or a variable geometry turbine vane system. In various embodiments, engine  20  may include instances of variable geometry vane system  60  adapted for use in one or more of fan  28 , compressor  32 , turbine  38  and/or turbine  40 . In still other embodiments, variable geometry vane system  60  may be employed in other types of turbomachines, e.g., including turbopumps or other types of turbomachinery that employs vanes and employ components which rotate about the turbomachine&#39;s axis of rotation. 
     Variable geometry vane system  60  includes a plurality of variable vanes  62  disposed between an inner flowpath wall  64  and an outer flowpath wall  66 . A flowpath wall is a structure that establishes a boundary for core flow or bypass flow in a turbomachine, such as a gas turbine engine. In an axial flow machine, flowpath walls bound the flow in the radial direction, forcing the flow into a generally axial direction, which may or may not include radial direction components, depending upon the particular engine configuration. In one form, inner flowpath wall  64  includes a fixed inner flowpath wall portion  68  and a rotatable flowpath wall portion  70 , each of which extend circumferentially around centerline  49  to form rings that are centered about centerline  49 . In other embodiments, rotatable flowpath wall portion  70  may be an outer flowpath wall, e.g., centered about centerline  49 . Rotatable flowpath wall portion  70  is configured to rotate about the compressor  32  axis of rotation, which in the present embodiment is centerline  49 . Rotatable flowpath wall portion  70  is configured to function as an integral flowpath wall/synchronization ring to synchronize the rotation of vanes  62  about respective vane axes of rotation (discussed below). In other embodiments, one or more portions of outer flowpath wall  66  may be configured as rotatable flowpath wall/synchronization ring in addition to or in place of rotatable flowpath wall portion  70 . 
     In one form, each vane  62  is split into a fixed vane leading edge portion  72  and a rotatable vane trailing edge portion  74 . Fixed vane leading edge portion  72  extends radially inward from a forward flowpath wall portion  76  of outer flowpath wall  66  to fixed inner flowpath wall portion  68 . Trailing edge portion  74  is configured to rotate (pivot) about a vane axis of rotation  78 . In other embodiments, vane  62  may take other forms, including without limitation, a rotatable leading edge portion with a fixed or rotatable trailing edge portion; or may be formed of three or more components, e.g., a leading edge portion, a central portion and a trailing edge portion, wherein the central portion is fixed, and the leading edge portion and trailing edge portion are rotatable. The rotation of one or more portions of vanes  62  may be accomplished via one or more types of mechanisms, for example and without limitation, those described herein. 
     Rotatable vane trailing edge portion  74  includes a tip pivot shaft  80  and a root pivot shaft  82 . In one form, pivot shafts  80  and  82  are integral with trailing edge portion  74 . In other embodiments, one or both of pivot shafts  80  and  82  may be otherwise coupled to or affixed to trailing edge portion  74 . Pivot shaft  80  is received into and piloted by a bushing  84 . Bushing  84  is received into an opening  86  of an aftward flowpath wall portion  88  of outer flowpath wall  66 . Pivot shaft  82  is received into and piloted by a bushing  90 . Bushing  90  is received into an opening  92  formed by sides  94  and  96  of a split inner ring  98 . Sides  94  and  96  of split inner ring  98  are clamped together and secured to a flange  100  extending from fixed inner flowpath wall portion  68  by a plurality of bolts  102  spaced apart circumferentially around split inner ring  98 . The locations and dimensions of openings  86  and  92 , bushings  84  and  90  and pivot shafts  80  and  82  form the axis of rotation  78  for each vane  62 . 
     Rotatable flowpath wall portion  70  includes a driving member  104 . Rotatable vane trailing edge portion  74  includes a driven member  106 , that when rotated, imparts rotation to rotatable vane trailing edge portion  74  about axis of rotation  78 . Driving member  104  is configured to engage driven member  106  and to impart rotation to driven member  106  upon a rotation of flowpath wall portion  70  about centerline  49 . In one form, driving member  104  is formed integrally with flowpath wall portion  70 . In other embodiments, driving member  104  may be formed separately and may be coupled or affixed to flowpath wall portion  70 . In one form, driving member  104  extends circumferentially along flowpath wall portion  70 . In a particular form, driving member  104  extends continuously along flowpath wall portion  70 . In other embodiments, driving member  104  may be subdivided into a plurality of portions, which in some embodiments may be spaced apart circumferentially along flowpath wall portion  70 . 
     In one form, driving member  104  is a gear having a plurality of teeth, e.g., a circumferential rack gear, and driven member  106  is a gear having a plurality of teeth, e.g., a pinion gear, that is in mesh with driving member  104 . In other embodiments, driving member  104  and driven member  106  may take other forms, e.g., metallic and/or composite belt drives, bell-crank drives or other suitable mechanical drive types. In one form, driven member  106  is formed integrally with rotatable vane trailing edge portion  74 , e.g., as part of pivot shaft  82 . In a particular form, driven member  106  extends from a larger diameter portion  82 A of pivot shaft  82 . In other embodiments, driven member may be formed separately and coupled or affixed to trailing edge portion  74  and/or pivot shaft  82 . 
     Referring to  FIG. 3  in conjunction with  FIGS. 2A and 2B , driving member  104  is retained in engagement with driven member  106  via a bearing  108 . For clarity of illustration, side  94  of split inner ring  118  is not shown in  FIG. 3 . In one form, bearing  108  is a rolling element bearing having a plurality of rolling elements  110  disposed between a forward race  112  and an aft race  114  and spaced apart circumferentially around bearing  108 . In other embodiments, bearing  108  may be one or more bearing surfaces that do not include rolling elements. Bearing  108  is retained in engagement with an aft face  116  of flowpath wall portion  70  by a retaining ring  118 , which is secured to side  94  of split inner ring  98  via a plurality of bolts  120  spaced apart circumferentially around retaining ring  118 . In particular, bolts  120  secure a lower lip  122  of retaining ring  118  to side  94  of split inner ring  98 . Lower lip  122  is disposed radially inward of bearing  108  and driving member  104 . 
     Referring to  FIG. 4  in conjunction with  FIGS. 2A ,  2 B and  3 , an actuator  124  is coupled between static structure, e.g., retaining ring  118 , and rotatable flowpath wall portion  70 . In one form, a linear actuator is employed. In other embodiments, actuator  124  may take one or more other forms. Actuator  124  is configured to impart rotation to flowpath wall portion  70  about centerline  49 , which transmits rotation to trailing edge portion  74  via driving member  104  and driven member  106 . Thus, variable geometry vane system  60  is configured to rotate at least part of each vane  62  (e.g., trailing edge portion  74 ) about its vane axis of rotation  78  with a rotation of the flowpath wall portion  70  about centerline  49 . The rotation of trailing edge portion  74  of vane  62  provides variable geometry to vane  62 . In some embodiments, a sensor  126  configured to sense an amount of the rotation of trailing edge portion  74  about vane axis of rotation  78  may be attached to one or more portions of trailing edge portion  74  or other component(s) that rotate with trailing edge portion  74 . The output of sensor  126  may be employed by a control systems, such as an engine control system, to aid in rotating trailing edge portion  74  to a desired degree. In one form, sensor  126  is an RVDT (rotary variable differential transformer). In other embodiments, other sensor types may be employed to detect the amount of rotation of trailing edge portion  74 . 
     Embodiments of the present invention include a variable geometry vane system for a vane stage of a turbomachine, comprising; a plurality of vanes, wherein each vane has a vane axis of rotation and is configured to rotate, at least in part, about the vane axis of rotation; and wherein each vane has a driven member configured, that when rotated, to impart rotation of at least part of the vane about the vane axis of rotation; and a flowpath wall configured to rotate about an axis of rotation of the turbomachine, wherein the flowpath wall has a driving member configured to engage the driven member and configured to impart rotation to the driven member upon rotation of the flowpath wall about a turbomachine axis of rotation. 
     In a refinement, the driving member is a first gear; and wherein the driven member is a second gear in mesh with the first gear. 
     In another refinement, the second gear extends circumferentially along the flowpath wall. 
     In yet another refinement, the flowpath wall forms an integral synchronization ring configured to synchronize the rotation of the plurality of vanes. 
     In still another refinement, the driving member is coupled to the synchronization ring. 
     In yet still another refinement, the flowpath wall is an inner flowpath wall. 
     In an additional refinement, the flowpath wall extends circumferentially about the turbomachine axis of rotation. 
     In a further refinement, wherein the flowpath wall forms a ring centered about the turbomachine axis of rotation. 
     In a yet further refinement, each vane includes a pivot shaft; and wherein the driven member is formed integrally with the pivot shaft. 
     In a still further refinement, the driven member is formed integrally with at least a part of each vane. 
     Embodiments of the present invention include a gas turbine engine, comprising: a fan having a fan axis of rotation; a compressor in fluid communication with the fan and having a compressor axis of rotation; a combustor in fluid communication with the compressor; a turbine in fluid communication with the combustor and having a turbine axis of rotation; and a variable geometry vane system, including: a plurality of vanes, wherein each vane has a vane axis of rotation and is configured to rotate, at least in part, about the vane axis of rotation; a flowpath wall configured to rotate about the fan and/or the compressor and/or turbine axis of rotation, wherein the variable geometry vane system is configured to rotate at least part of each vane about the vane axis of rotation with a rotation of the flowpath wall about the fan, compressor and/or the turbine axis of rotation. 
     In a refinement, each vane has a driven member configured, that when rotated, to impart rotation to at least part of the vane about the vane axis of rotation; wherein the flowpath wall has a driving member configured to engage the driven member and configured to impart rotation to the driven member upon rotation of the flowpath wall about the fan, compressor and/or turbine axis of rotation. 
     In another refinement, the driving member is integral with the flowpath wall. 
     In yet another refinement, the driven member of each vane is integral with the each vane. 
     In still another refinement, the gas turbine engine further comprises an actuator configured to impart rotation to the flowpath wall about the fan, compressor and/or the turbine axis of rotation. 
     In yet still another refinement, the gas turbine engine further comprises a sensor configured to sense an amount of the rotation of at least part of at least one vane about the vane axis of rotation. 
     In a further refinement, the sensor is a rotary variable differential transformer. 
     In a yet further refinement, each vane has a leading edge and a trailing edge portion, and wherein the trailing edge portion is configured to rotate about the vane axis of rotation. 
     In a still further refinement, the leading edge portion is stationary and not configured to rotate about the vane axis of rotation. 
     Embodiments of the present invention include a gas turbine engine, comprising: a fan having a fan axis of rotation; a compressor in fluid communication with the fan and having a compressor axis of rotation; a combustor in fluid communication with the compressor; a turbine in fluid communication with the combustor and having a turbine axis of rotation; and a variable geometry vane system, including: a plurality of vanes, wherein each vane has a vane axis of rotation and is configured to rotate, at least in part, about the vane axis of rotation; and means for rotating at least a part of each vane about its vane axis of rotation. 
     In a refinement, the means for rotating includes a flowpath wall configured to rotate about the fan, compressor and/or turbine axis of rotation. 
     In another refinement, the flowpath wall forms an integral synchronization ring configured to synchronize the rotation of the plurality of vanes. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.