Abstract:
An assembly system for assembling a gas turbine engine including a support beam defining a horizontal plane for assembly of engine components along a horizontal axis substantially parallel with the support beam. A forward arm is supported on the support beam for supporting a forward portion of an engine component. An aft arm is supported on the support beam for supporting an aft portion of the engine component. An aft mounting ring is attachable to an aft end of an engine assembly. A forward mounting ring is attachable to a forward end of the engine assembly. A drive is mounted to the aft arm engageable to the aft mounting ring for rotating the engine assembly about the horizontal axis. A roller is supported on the forward arm and engageable to the forward mounting ring to support the first end of the engine assembly during rotation about the horizontal axis. A method is also disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to U.S. Provisional Application No. 62/011,894 filed on Jun. 13, 2014. 
     
    
     BACKGROUND 
       [0002]    A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines. 
         [0003]    A gas turbine engine includes several components that are housed in casings that are assembled together through bolted flanges. In some systems, the gas turbine engine is assembled along a vertical axis and can complicate access to structures about the engine. Moreover, during engine assembly not only are specific components assembled to each other along a common axis, but accessory components and devices are attached to outer casing structures. Engine assembly requires assembling specific case structures together and assembly of accessory components to the case structures. Each accessory component may require wiring for electrical communication and tubing to communicate fluids. The quantity of wires and tubing required for each accessory component can complicate the assembly process. 
         [0004]    Accordingly, it is desirable to design a system for assembling an engine that provides repeatability while easing access to each component and section to speed and simplify assembly. 
       SUMMARY 
       [0005]    In one exemplary embodiment, an assembly system for assembling a gas turbine engine including a support beam defining a horizontal plane for assembly of engine components along a horizontal axis substantially parallel with the support beam. A forward arm is supported on the support beam for supporting a forward portion of an engine component. An aft arm is supported on the support beam for supporting an aft portion of the engine component. An aft mounting ring is attachable to an aft end of an engine assembly. A forward mounting ring is attachable to a forward end of the engine assembly. A drive is mounted to the aft arm engageable to the aft mounting ring for rotating the engine assembly about the horizontal axis. A roller is supported on the forward arm and engageable to the forward mounting ring to support the first end of the engine assembly during rotation about the horizontal axis. 
         [0006]    In a further embodiment of the above, includes at least one additional arm disposed between the forward arm and the aft arm for supporting a portion of the engine assembly. 
         [0007]    In a further embodiment of any of the above, the at least one additional arm includes a first arm and a second arm movable vertically relative to the support beam. 
         [0008]    In a further embodiment of any of the above, includes an end assembly supported on one of the at least one additional arm. The end assembly includes a lateral adjustment linkage for aligning an engine component secured thereto in a direction transverse to the horizontal axis. 
         [0009]    In a further embodiment of any of the above, the end assembly includes first and second clamps set apart from each other on opposite sides of an engine centerline. 
         [0010]    In a further embodiment of any of the above, includes a first mount secured to the engine assembly and engageable with the first arm and a second mount secured to the engine assembly and engageable with second arm. 
         [0011]    In a further embodiment of any of the above, each of the forward arm and the aft arm are supported on a sliding support movable along the support beam. 
         [0012]    In a further embodiment of any of the above, the aft arm and the forward arm are each movable between a stowed position and a mount position. 
         [0013]    In a further embodiment of any of the above, includes a motor corresponding with each of the forward arm and the aft arm for driving a linkage to move the corresponding one of the forward arm and the aft arm between the stowed position and the mount position. 
         [0014]    In a further embodiment of any of the above, the aft arm is movable about a pivot between the stowed and mount positions. 
         [0015]    In a further embodiment of any of the above, the forward arm is movable vertically to adjust spacing between the support beam and the roller. 
         [0016]    In a further embodiment of any of the above, the aft mounting ring includes locking features engageable to the drive mounted on the aft arm. 
         [0017]    In a further embodiment of any of the above, the forward mounting ring includes a groove receiving a roller of the roller assembly for supporting the forward portion of the engine assembly. 
         [0018]    In a further embodiment of any of the above, includes at least one cart for supporting an engine component relative to the horizontal axis that enables positioning of the supported engine component in at least two directions. 
         [0019]    In another exemplary embodiment, a method of assembling a gas turbine engine includes attaching an aft mounting ring to an aft portion of an aft engine section, attaching a forward mounting ring to a forward portion of a forward engine section, supporting a first intermediate engine section along a horizontal axis, attaching the aft engine section to the intermediate engine component, supporting a portion of the aft engine section along a horizontal axis with a drive supported on an aft arm by attaching the aft mounting ring to the drive, supporting a portion of the forward engine section along the horizontal axis with a roller assembly supported on a forward arm by coupling the roller assembly to the forward mounting ring, rotating the aft, first intermediate and forward engine sections about the horizontal access with the drive supported on the aft arm, and performing assemble operations on the aft, first intermediate, and forward engine sections. 
         [0020]    In a further embodiment of the above, the drive includes a motor driving a gear assembly and the aft mounting ring includes gear teeth engaged by the gear assembly for driving rotation of the aft engine section about the horizontal axis. 
         [0021]    In a further embodiment of any of the above, the forward mounting ring includes a track for receiving rollers of the roller assembly and supporting the forward engine section includes inserting the rollers into the track of the forward mounting ring. 
         [0022]    In a further embodiment of any of the above, supporting the first intermediate engine section along the horizontal axis includes fixing a first arm to a first mount attached to the first intermediate engine and a second arm to a second mount attached to the first intermediate engine section. 
         [0023]    In a further embodiment of any of the above, includes detaching the first arm and the second arm from the corresponding first mount and second mount prior to rotating the aft, first intermediate, and forward engine sections about the horizontal axis. 
         [0024]    In a further embodiment of any of the above, includes aligning the aft engine section along the horizontal axis with a cart, wherein the cart enables positioning of the aft engine section in at least two axes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a schematic illustration of an example gas turbine engine. 
           [0026]      FIG. 2  is a schematic illustration of an example assembly system for assembling a gas turbine engine. 
           [0027]      FIG. 3  is a schematic view of an initial step for assembling a gas turbine engine. 
           [0028]      FIG. 4  is a further schematic illustration of the first assembly step. 
           [0029]      FIG. 5  is a perspective view of an example end assembly for supporting a subassembly of a gas turbine engine. 
           [0030]      FIG. 6  is a schematic illustration of a subsequent step for installing a low pressure turbine section. 
           [0031]      FIG. 7  is a schematic illustration of a subassembly of a gas turbine engine supported by the example assembly system. 
           [0032]      FIG. 8  is a perspective view of an example fan case mount ring. 
           [0033]      FIG. 9  is a schematic illustration of an assembly step for assembling a fan compressor section. 
           [0034]      FIG. 10  is another schematic illustration showing an engine subassembly supporting forward and aft positions. 
           [0035]      FIG. 11  is a perspective view of an example mount ring attachable to provide and support rotation about a horizontal axis. 
           [0036]      FIG. 12  is an enlarged view of a roller assembly and mount ring. 
           [0037]      FIG. 13  is a perspective view of an example roller assembly. 
           [0038]      FIG. 14  is a schematic view of a preparation step for attaching a fan section. 
           [0039]      FIG. 15  is a schematic view of an initial assembly operation for attaching a fan case section to another engine subassembly. 
           [0040]      FIG. 16  is a schematic view of the engine subassembly supported by the assembly system. 
       
    
    
       [0041]    The embodiments, examples and alternatives of the preceding paragraphs, the claims, and the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible. 
       DETAILED DESCRIPTION 
       [0042]      FIG. 1  schematically illustrates an example gas turbine engine  20  that includes a fan  22 , a compressor  24 , a combustor  26  and a turbine  28 . Alternative engines might include an augmenter section (not shown) among other systems or features. The fan  22  drives air along a bypass flow path B while the compressor  24  draws air in along a core flow path C where air is compressed and communicated to a combustor  26 . In the combustor  26 , air is mixed with fuel and ignited to generate a high pressure exhaust gas stream that expands through the turbine  28  where energy is extracted and utilized to drive the fan  22  and the compressor  24 . 
         [0043]    The example gas turbine engine  20  includes several sections that are attached to each other during assembly. In this example, the gas turbine engine  20  includes a core engine section  30 , a low pressure turbine section  46 , a fan drive/compressor (FDC) section  54  and a fan section  62 . The core engine section  30  includes combustor  26 , a high spool  34  and a mid-turbine frame  44 . The high spool  34  includes a high pressure compressor  36  coupled to a high pressure turbine  38  through high spool shaft  40 . The components of the core engine section  30  are mounted within several cases that are secured to each other and are referred to in this disclosure as an intermediate case  42 . 
         [0044]    The low pressure turbine section  46  includes low pressure turbine  48  and the low spool shaft  50  supported within a low pressure turbine case  52 . The FDC section  54  includes the low pressure compressor  58  and fan drive gear system  56  supported within a FDC case  60 . The fan  22  is housed within a fan case of the fan section  62 . The fan  22  includes a plurality of blades  66  supported for rotation about the engine axis A. Each of the sections  30 ,  46 ,  54  and  62  are disposed about the engine axis A. 
         [0045]    It should be appreciated, that components of each of the disclosed sections  30 ,  46 ,  54  and  62  are described by way of example and different and/or additional components could be included in the various sections. Moreover, although the disclosed non-limiting embodiment depicts a turbofan gas turbine engine, it should be understood that the concepts described herein are not limited to use with turbofans as the teachings may be applied to other types of turbine engines; for example a turbine engine including a three-spool architecture in which three spools concentrically rotate about a common axis and where a low spool enables a low pressure turbine to drive a fan via a gearbox, an intermediate spool that enables an intermediate pressure turbine to drive a first compressor of the compressor section, and a high spool that enables a high pressure turbine to drive a high pressure compressor of the compressor section. 
         [0046]    Referring to  FIG. 2 , an example assembly system  68  provides for the horizontal assembly and disassembly of engine sections  30 ,  46 ,  54  and  62 . Horizontal assembly enables each of the sections  30 ,  46 ,  54  and  62  to be supported and assembled along a horizontal axis such that each section and component about the entire circumference of the engine  20  is easily accessible to a technician during assembly. 
         [0047]    The example system  68  includes sliding supports  72  extending from a beam  70 . Each of the supports  72  is movable horizontally along the beam  70  and includes a lock  82  for holding the support in place along the beam  70 . Each of the supports  72  holds an arm that includes features for attachment to the engine sections. In this example a first arm  74  includes an end  86  attachable to a forward mount  45  attached to the core engine section  30 . A second arm  76  includes an end assembly  88  for attachment to an aft mount  85  attached to the core engine section  30 . The supports  72  are movable horizontally along the beam  70  prior to attachment to an engine section. The supports  72  lock in place to prevent horizontal movement. 
         [0048]    A third or aft arm  90  is movable between a stowed position ( FIG. 3 ) and a mounting position shown in  FIG. 2 . The third arm  90  supports a motor  92  that drives a gear assembly  138 . A fourth or forward arm  102  includes a roller assembly  114 . A controller  150  is in communication with sensors and load cells mounted throughout the system  68  to provide information indicative of the position of components during assembly and the loads on each part of the system  68 . This information is utilized to execute safety protocols and proper alignments. 
         [0049]    The example system  68  includes features enabling complete 360 degree rotation of subassemblies of the engine about the horizontal axis A. The horizontal axis A and the engine axis in this disclosed example are the same. Continuous 360 degree rotation about the axis A aids and simplifies assembly and eases access to portions of the engine sections to facilitate assembly of the engine. Rotation is enabled by mount rings  106  and  116  for a forward part of an engine subassembly and the gear assembly  138  and mount ring  100  at the aft end. The mount ring  100  attaches to a geared ring  94  that is driven by the gear assembly  138  driven by the motor  92 . The motor  92  drives rotation of the engine during assembly and the roller assembly  114  supports and enables rotation of the forward part of the engine subassembly. In various stages of assembly the roller assembly  114  will be engaged to the mount ring  106  or the fan case mount ring  100 . 
         [0050]    Referring to  FIGS. 3 and 4 , assembly begins by moving the core engine section  30  into position under the first arm  74  and the second arm  76 . The core engine section  30  is supported on a first cart  120  that enables movement of the core engine section  30  along all axes for aligning the core engine section  30  with the first and second arms  74 ,  76 . 
         [0051]    The core engine section  30  includes a forward flange  122  and a rear flange  124 . Once the core engine section  30  is in position, the first arm  74  is moved downward by a jack screw shaft  75  ( FIG. 4 ) driven by an electric motor  78 . The forward mount  45  and aft mount  85  are attached to the case  42  and are adapted to the configuration of the core case  42 . Each of the forward mount  45  and aft mount  85  includes features for attachment to the corresponding one of the first arm  74  and the second arm  76 . The first arm  74  attaches to the forward mount  45  and the second arm  76  attaches to the aft mount  85 . Attachment between the first and second arms  74 ,  76  and the forward and aft mounts  45 ,  85  are fixed and do not enable rotation about the horizontal axis. 
         [0052]    Referring to  FIG. 5  with continued reference to  FIG. 4 , the second arm  76  is moved downward toward the core engine section  30  with the gas spring  80  compensating for the weight of the second arm  76  to enable manual adjustment. Further movement of the arm  76  is enabled to provide fine alignment with the engine section. The gas spring  80  relieves weight on the scissor mechanism  126  and controls movement by slowing momentum. The attachment mechanism  126  holds a vertical position of the arm  76  once it is attached to the core engine section  30 , and the core engine section  30  is set at a desired height. It should be understood, that other mechanisms for moving the attachment mechanism  88  into place relative to the core engine section  30  are within the contemplation of this disclosure. 
         [0053]    The attachment mechanism  88  further includes a lateral slide  128  that includes first and second lock pins  132 A and  132 B disposed on either circumferential side of a centerline of the engine core section  30 . The lock pins  132 A and  132  B engage the engine mounts  45  and  85  to support the core engine section  30 . The lateral slide  128  centralizes the load and provides for lateral adjustment of the core engine section  30  once suspended from the beam  70 . It should be understood that other configurations for interfacing with the engine mounts  45  and  85  are within the contemplation of this disclosure. 
         [0054]    Referring to  FIGS. 6 and 7 , the low pressure turbine (LPT) section  46  is then moved along the horizontal axis for assembly to the core engine section  30 . The LPT section  46  is supported on a second cart  136  that provides movement of the LPT section  46  along all axes to enable alignment along the horizontal axis with the core engine section  30 . The core engine section  30  is supported on the first and second arms  74 ,  76  suspended from the upper support beam  70  and the LPT section  46  is supported on the cart  136  during assembly. Each of the arms  74 ,  76  is movable vertically to aid in alignment with the LPT section  46 . In this example, the LPT section  46  includes the shaft  50  that extends along the horizontal axis and is assembled through the core engine section  30 . 
         [0055]    Once the LPT section  46  is aligned with the core engine section  30  and the shaft  50  is inserted therethrough, the sections  46  and  30  are attached to each other. Attachment in this example includes attachment of the rear flange  124  of the core engine section  30  to a forward flange  134  of the LPT section  46 . The shaft  50  extends out a forward end of the core engine section  30 . The aft flange  124  and the forward flange  134  form a connection  140  ( FIG. 7 ) between the core engine section  30  and the LPT section  46 . 
         [0056]    Once the connection  140  is complete, the aft portion of the LPT section  46  is mounted to the aft arm  90 . The aft arm  90  is pivoted to the mount position by actuation of a motor  96  that drives jack screw  93  to drive link  95  and move arm  90  into position. The arm  90  includes a geared ring  94  that attaches to the mount ring  100  secured to the LPT section  46 . The fan case mount ring  100  ( FIG. 8 ) is an adaptor that is not part of the completed engine and is utilized to facilitate assembly on the arm  90 . The fan case mount ring  100  includes a slots  107  that provide for mating engagement of an aft portion of the engine to other assembly or test systems. 
         [0057]    Referring back to  FIGS. 6 and 7 , the arm  90  is pivoted downward to the mount position by the electric motor  96  that drives the jack screw  93  to drive link  95  such that the geared ring  94  engages the mount  100  ring. An electric motor  92  is supported on the arm  90  and drives the gear assembly  138  in driving engagement with the geared ring  94 . The electric motor  92  includes a sensor that provides information indicative of a rotational position of the assembly to the controller  150 . The gear assembly  138  enables rotation of the engine subassembly about the engine axis A. 
         [0058]    However, in the state illustrated in  FIG. 7 , it should be appreciated that although the LPT section  46  is mounted for rotation, the subassembly is not yet rotatable because the first and second arms  74 ,  76  are attached to fixed points on the core engine section  30 . The motor  92  is therefore locked from rotation until a further rotational support link is provided. 
         [0059]    Referring to  FIG. 9  once the LPT section  46  is attached to the core section  30 , the FDC section  54  is installed. A mounting ring  106  ( FIG. 11 ) is attached to the FDC section  54  for engagement with a roller assembly  114  ( FIG. 13 ) to support rotation of the front portion of the engine subassembly. The mounting ring  106  is engageable with the roller assembly  114  that facilitates rotational movement. 
         [0060]    The FDC section  54  is supported on a third cart  142  that also provides for movement in all axes to facilitate alignment with the core section  30 , and the shaft  50  of the LPT section  46 . In this step, the FDC section  54  is aligned with the core engine section  30  and the shaft  50 . An aft flange  146  of the FDC section is attached to the forward flange  122  of the core engine section  30 . The shaft  50  is coupled to the fan drive gear system  56  (not shown here) disposed within the FDC case  60 . 
         [0061]    Referring to  FIGS. 10 , and  12 , once the FDC section  60  is attached to the core section  30 , the forward arm  102  is engaged to the ring  106 . The forward arm  102  supports the roller assembly  114 . The roller assembly  114  is moved into position utilizing motor  110  that drives ball screw  115  to move the support  72  into horizontal position. Motor  108  is utilized to move the arm  102  vertically once the motor  110  has moved the arm  102  into a horizontal position. Rollers  112  of the roller assembly  114  are inserted into a groove  105  of the ring  106  to support the engine subassembly and rotation. 
         [0062]    Referring to  FIG. 13 , with continued attention to  FIGS. 10 and 12 , the roller assembly  114  includes two rollers  112  that are received within the groove  105  of the ring  106 . The rollers  112  are spaced apart horizontally to provide stability in support of the engine subassembly. Sensors schematically indicated at  104  are provided to verify correct positioning of the roller assembly  114  within the groove  105  of the mount ring  106 . The sensor  104  provides information to the controller  150  that is in communication and control over the actuators and various sensors of the assembly system  68 . 
         [0063]    Once the roller assembly  114  is engaged with the ring  106 , the first and second arms  74 ,  76  can be disconnected from the core engine section  30 . Once the first and second arms  74 ,  76  are disconnected the entire engine subassembly is supported between the forward arm  102  and the third arm  90 . Accordingly, full 360 degree rotation around the horizontal axis of the engine subassembly is enabled. Rotation of the subassembly is provided by actuating the motor  92  to drive the gear assembly  138  to rotate the gear ring  94 . The gear assembly  138  includes gear teeth that engage gear teeth defined on the gear ring  94 . 
         [0064]    Referring to  FIG. 15 , once assembly operations on the subassembly are complete including operations on the core section  30 , LPT section  46  and FDC section  54  the subassembly is prepared for installation of the fan section  62 . Installation of the fan section includes coupling to the FDC section  54  and attachment of sub components of the fan case  64  to the FDC case  60 . 
         [0065]    In preparation for assembly of the fan section, the first arm  74  is reattached to the core section  30 . The first arm  74  is rigidly attached meaning that rotation is not possible. Accordingly, the subassembly is supported by the first arm  74  and by the aft arm  90 . Once the subassembly is supported by the first arm, the arm  102  can be disconnected by removing the roller assembly  114  from the ring  106  and move the arm  102  forward and upward. Each of the arms  74  and  90  are raised to place the subassembly in a position that enables alignment with the fan case  64 . The mount ring  106  is removed and subassembly is ready for assembly of the fan case section  62 . 
         [0066]    Referring to  FIGS. 15 and 16 , the fan case  64  is moved along the horizontal axis into alignment with the FDC section  30  on cart  148 . The cart  148  includes features that enable movement of the fan case  64  for alignment along the horizontal axis with the other subassembly components supported by arms extending from the upper beam  70 . The fan case  64  includes a mounting ring  116  configured to receive the rollers  112  of the roller assembly  114 . 
         [0067]    Once the fan case  62  is attached to the FDC case  54 , the roller assembly  114  is lowered into position and the rollers  112  ( FIGS. 12 and 13 ) are inserted into grooves defined within the mounting ring  116 . The mounting ring  116  includes a configuration similar to that of the mount ring  106 , except that the mounting ring  116  is a size appropriate for the fan case  64  and features compatible with attachment to the fan case  64 . The engine subassembly is therefore supported at the forward end by the roller assembly  114  and at the aft end by the gear assembly  138  and ring gear  94 . In this supported condition, the engine subassembly may then be rotated around the horizontal axis a full 360 degrees to enable access to all portions of the outer engine assembly for mounting the accessory components to each of the outer case portions and surfaces. 
         [0068]    Accordingly, the example assembly system enables efficient assembly operation in a reduced vertical space that simplifies access to components. 
         [0069]    Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure.