Abstract:
A system and methods for disassembling a rotary machine are provided. The rotary machine includes a casing having a plurality of arcuate channels. The system includes a reaction bridge that is configured to couple to the casing of the rotary machine such that the reaction bridge is moveable along a length of the casing. The reaction bridge includes a front support and a rear support that is substantially parallel to the front support. Each of the supports includes a first leg, a second leg, and a support beam extending therebetween. A force device including an actuator and an engaging rod extending therefrom is coupled to the reaction bridge. The force device is configured to apply a force substantially tangentially to a segment positioned in one of the casing arcuate channels.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation and claims priority to U.S. patent application Ser. No. 12/110,729 filed Apr. 28, 2008 for “METHODS AND SYSTEM FOR DISASSEMBLING A MACHINE,” which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The field of the invention relates generally to gas turbine engines, and more particularly, to a system and methods for removing stator vane segments from a turbine engine. 
     At least some known gas turbine engines include, in serial flow arrangement, a high-pressure compressor for compressing air flowing through the engine, a combustor wherein fuel is mixed with the compressed air and ignited to form a high temperature gas stream, and a high pressure turbine. Hot combustion gases are channeled downstream from the combustor towards the turbine, wherein energy is extracted from the combustion gases for use in powering the compressor, as well as producing useful work to propel an aircraft in flight or to power a load, such as in an electrical generator. Some known gas turbine engines may also include a low-pressure compressor, or booster compressor, to supply compressed air to the high pressure compressor. 
     Known compressors include a compressor casing that may include upper and lower casing sections that are coupled about a rotor assembly. Known compressors include a plurality of alternating rows of circumferentially-spaced stator and rotor blades. Each row of rotor and stator blades includes a series of airfoils that each include a pressure side and a suction side that are coupled together at leading and trailing edges. Each stator blade airfoil extends radially inward from a stator support ring that is inserted into channels that are circumferentially formed in axial succession within a radially-inner side of the combustor casing. Each stator ring is sized and shaped to receive a plurality of stator blade segments that extend circumferentially in a row between a pair of adjacent rows of rotor blade assemblies. 
     During operation, leading and trailing edges and/or an outer tip of the stator blade may deteriorate or become damaged due to oxidation, thermal fatigue cracking, or erosion caused by abrasives and corrosives in the flowing gas stream. Over time such deterioration may cause some known stator blades to fail, resulting in the airfoil portion becoming detached from a dovetail portion of the blade. In some instances, blade failures have caused catastrophic damage within their engine. To facilitate mitigating such operational effects, blades are periodically inspected for damage, to enable a determination of an amount of damage and/or deterioration to be made. Blades are generally replaced if the damage and/or deterioration meets a certain pre-determined threshold. Alternatively, if the blades have not lost a substantial quantity of material, the blades may be repaired. 
     For example, at least one known method of replacing stator support ring segments requires the removal of the upper compressor section casing and rotor assemblies. Following rotor assembly removal, each stator blade segment is heated and after reaching a desired temperature, the segment is quenched to facilitate rapid cooling. Each segment is then withdrawn from its respective channel using, for example, a pneumatic peening hammer. A newly fabricated segment is then inserted into the casing channel. Alternatively, after being removed from the rotor assembly, each damaged or deteriorated segment is repaired and refurbished prior to being replaced within the casing channel. However, rotor assembly removal, reinsertion, and compressor reassembly may be a time-consuming and expensive process that may significantly increase repair time and power generator outages. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one aspect, a method for disassembling a rotary machine is provided. The method includes at least partially disassembling a casing of the rotary machine to provide access to an arcuate channel defined in the casing. The method also includes coupling a reaction bridge to the casing of the rotary machine. The reaction bridge includes a first leg, a second leg, and a support beam extending therebetween. The reaction bridge also includes a force device removably coupled to the reaction bridge. The method further includes engaging a segment positioned in the arcuate channel using a force device, applying a force to the segment such that the segment is repositioned within a portion of the arcuate channel, and removing the segment from the arcuate channel. 
     In another aspect, a system for disassembling a rotary machine is provided. The rotary machine includes a casing including a plurality of arcuate channels defined therein. The system includes a reaction bridge configured to removably couple to the casing of the rotary machine such that the reaction bridge is moveable along a length of the casing. The reaction bridge includes a front support and a rear support that is substantially parallel to the front support. Each of the front and rear supports include a first leg, a second leg, and a support beam extending therebetween. The system also includes a force device including an actuator and an engaging rod extending therefrom. The force device is removably coupled to the reaction bridge. The force device is configured to apply a force substantially tangentially to a segment positioned in one of the casing arcuate channels. 
     In yet another aspect, a method for disassembling a rotary machine is provided. The rotary machine includes a casing having an arcuate channel defined therein. The method includes applying an inward force to a segment positioned in the arcuate channel of the rotary machine using a first force device that is removably coupled to a reaction bridge. The reaction bridge is coupled to the casing of the rotary machine and includes a first leg, a second leg, and a support beam extending therebetween. The inward force is applied such the segment is repositioned within a portion of the arcuate channel. The method also includes determining that the segment is mechanically frozen within the channel, and applying an outward force to the segment using a second force device removably coupled to the reaction bridge such that the segment is further repositioned within a portion of the arcuate channel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of an exemplary gas turbine engine; 
         FIG. 2  is an enlarged cross-sectional view of a portion of a compressor that may be used with the gas turbine engine shown in  FIG. 1  and taken along area  2 ; 
         FIG. 3  is a perspective view of an exemplary stator blade ring segment that may be used with the compressor shown in  FIG. 2 ; 
         FIG. 4  is a top view of an exemplary drilling system. 
         FIG. 5  a fragmentary elevation view of the drilling system shown in  FIG. 4 . 
         FIG. 6  is an end perspective view of a segment removal system coupled to the compressor shown in  FIG. 2 . 
         FIG. 7  is a side perspective view of the segment removal system coupled to the compressor shown in  FIG. 2 . 
         FIG. 8  is an elevation view of an exemplary force device that may be used with the segment removal system shown in  FIGS. 6 and 7 . 
         FIG. 9  is a side perspective view of the force device used with the segment removal system shown in  FIGS. 6 and 7 . 
         FIG. 10  is an elevation view of a force device used with segment removal system shown in  FIGS. 6 and 7 . 
         FIG. 11  is a side view of the force device shown in  FIG. 10  and used with segment removal system shown in  FIGS. 6 and 7 . 
         FIG. 12  is an assembly view of an exemplary clevis assembly used with the force device shown in  FIGS. 10 and 11 . 
         FIG. 13  is a partial elevation view of the exemplary clevis assembly shown in  FIG. 12 . 
         FIG. 14  is an elevation view of a pivot cradle assembly that may be used with the force device shown in  FIGS. 10 and 11 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a schematic illustration of an exemplary gas turbine engine  100 . Engine  100  includes a compressor  102  and a plurality of combustors  104 . Combustor  104  includes a fuel nozzle assembly  106 . Engine  100  also includes a turbine  108  and a common compressor/turbine rotor  110  (sometimes referred to as rotor  110 ). 
       FIG. 2  is an enlarged cross-sectional view of a portion of compressor  102  taken along area  2  (shown in  FIG. 1 ). Compressor  102  includes a rotor assembly  112  and a stator assembly  114  that are positioned within a casing  116  that at least partially defines a flow path  118  in cooperation with at least a portion of a casing radially inner surface  119 . In the exemplary embodiment, rotor assembly  112  forms a portion of rotor  110  and is rotatably coupled to a turbine rotor (not shown). Rotor assembly  112  also partially defines an inner flow path boundary  120  of flow path  118 , and stator assembly  114  partially defines an outer flow path boundary  122  of flow path  118 , in cooperation with inner surface  119 . Alternatively, stator assembly  114  and casing  116  are formed as a unitary and/or integrated component (not shown). 
     Compressor  102  includes a plurality of stages  124 , wherein each stage  124  includes a row of circumferentially-spaced rotor blade assemblies  126  and a row of stator blade assemblies  128 , sometimes referred to as stator vanes. Rotor blade assemblies  126  are coupled to a rotor disk  130  such that each blade assembly  126  extends radially outwardly from rotor disk  130 . Moreover, each assembly  126  includes a rotor blade airfoil portion  132  that extends radially outward from a blade coupling portion  134  to a rotor blade tip portion  136 . Compressor stages  124  cooperate with a motive or working air including, but not limited to, air, such that the motive air is compressed in succeeding stages  124 . 
     Stator assembly  114  includes a plurality of rows of stator rings  137 , sometimes referred to as segmented stators, stator-in-rings, stator support rings, and/or stator dovetail rings. Rings  137  are inserted into passages or channels  139  that extend circumferentially, in axial succession, within at least a portion of casing  116 . Each channel  139  is defined to be substantially axially adjacent to a portion of casing  116  that is radially outward from and opposite rotor blade tip portions  136 . Each stator ring  137  is sized and shaped to receive a plurality of stator blade assemblies  128  such that each row of blade assemblies  128  is positioned between a pair of axially adjacent rows of rotor blade assemblies  126 . In the exemplary embodiment, each blade assembly  128  includes an airfoil portion  140  that extends from a stator blade dovetail portion (not shown in  FIG. 2 ) to a stator blade tip portion  144 . Compressor  102  includes one row of stator vanes  138  per stage  124 , some of which are bleed stages (not shown in  FIG. 2 ). Moreover, in the exemplary embodiment, compressor  102  is substantially symmetric about an axial centerline  152 . 
     In operation, compressor  102  is rotated by turbine  108  via rotor  110 . Air collected from a low pressure region  148  via a first stage of compressor  102  is channeled by rotor blade airfoil portions  132  towards airfoil portions  140  of stator blade assemblies  128 . The air is at least partially compressed and a pressure of the air is at least partially increased as the air is channeled through flow path  118 . More specifically, the air continues to flow through subsequent stages that are substantially similar to the first stage  124  with the exception that flow path  118  narrows with successive stages to facilitate compressing and pressurizing the air as it is channeled through flow path  118 . The compressed and pressurized air is subsequently channeled into a high pressure region  150  for use within turbine engine  100 . 
       FIG. 3  is a perspective view of an exemplary stator blade ring segment  154  that may be used with compressor  102  (shown in  FIG. 2 ). In the exemplary embodiment, segment  154  includes a plurality of stator blade passages  156  that are each defined within segment  154 . Moreover, each passage  156  is sized and shaped to receive a stator blade assembly  128  therein. Each assembly  128  includes a stator blade dovetail portion  158  that enables stator blade assemblies  128  to be coupled to casing  116  via stator blade passages  156 . In the exemplary embodiment, each stator blade ring segment  154  is coupled to casing  116  via coupling methods that include, but are not limited to, a friction fit, the use of retention hardware (not shown), a welding process, and/or any other mechanical coupling means, and forming segments  154  integrally with casing  116 . A plurality of ring segments  154  are inserted into each channel  139  such that segments  154  extend substantially circumferentially within compressor casing  116  and such that circumferentially adjacent segments  154  abut each other. As such, ring segments  154  form at least a portion of outer path flow boundary  122 . 
     Referring to  FIGS. 4 and 5 ,  FIG. 4  is a top view of an exemplary compressor  200  that includes a casing section  202  and an exemplary drilling system  203 .  FIG. 5  is a fragmentary elevation view of compressor  200  and drilling system  203 , and illustrates five stator blade stages S 0 , S 1 , S 2 , S 3  and S 4  within casing section  202 . Arrow  204  represents an airflow direction through compressor  200 . In the exemplary embodiment, casing section  202  includes a first horizontal flange  206  and a second horizontal flange  208  that each extend radially outward from a mid compressor case  209 . Casing section  202  includes a plurality of channels  210 , including channel ends  211 , that are circumferentially defined in axial succession within at least a portion of casing section  202 . A plurality of blade segments  212  including stator blades (not shown) are inserted into each channel  210  such that segments  212  extend substantially circumferentially within casing section  202  and such that circumferentially adjacent segments  212  abut each other. In the exemplary embodiment, each channel  210  includes three segments  212 . Alternatively, each channel  210  may include any number of segments  212  that enables compressor  200  to function as described herein. 
     In preparation for removing blade segments  212 , at least one mounting plate  214  including a top surface  215 , is coupled to either first horizontal flange  206  and/or to second horizontal flange  208 . Mounting plate  214  includes a plurality of holes  216  that enable drilling system  203  to be coupled securely thereto, as described in detail below. A mounting plate inner surface  218  includes a series of recessed portions  220  that substantially align with channel ends  211 . Mounting plate inner surface  218  is aligned with segment inner surface  221  at a mating surface  222  and is coupled thereto. In the exemplary embodiment, mounting plate  214  is fabricated from steel. Alternatively, mounting plate  214  may be fabricated from any material that enables drilling system  203  to function as described herein. 
     In the exemplary embodiment, drilling system  203  includes at least one drill  230 , a bushing locator plate  232 , a plurality of drill guide bushings  234  and a plurality of fasteners  236  extending therebetween. Bushing locator plate  232  is sized to be positioned upon mounting plate top surface  215  such that plate  232  is substantially aligned with mounting plate  214  and such that a plurality of recessed sections  238  defined within plate  232  are aligned with mounting plate recessed portions  220 . In the exemplary embodiment, drill  230  is magnetically coupled to mounting plate  214 . Alternatively, drill  230  may be coupled to mounting plate  214  using any means that enables drill  230  to function as described herein. In the exemplary embodiment, drill guide bushings  234  are positioned at each channel end  211 , and coupled to bushing locator plate  232  via a plurality of fasteners  236 . 
     In operation, drilling system  203  facilitates removal of stator vane segment  212 . Specifically, in the exemplary embodiment, drill  230  forms a reference bore (not shown) in segment end  240 . Bushing locator plate  232 , drill guide bushings  234 , and fasteners  236  are then removed and drill  230  forms three holes (shown in  FIG. 12 ) in segment end  240  that each extend from a predetermined depth. More specifically, in the exemplary embodiment, the three holes are bored into segment outer portion  241 , through stator blade dovetail portion  242 , and partially into an adjacent stator blade segment portion  244 . 
     Referring to  FIGS. 6 and 7 ,  FIGS. 6 and 7  are a respective end perspective view and a side perspective view of compressor  200  with an exemplary segment removal system  300  installed. As described herein, compressor  200  includes casing section  202  and rotor  110 . In the exemplary embodiment, segment removal system  300  includes a reaction bridge  305  that includes a forward support  308  and rear support  310  that are substantially parallel to each other. Moreover, each support  308 ,  310  includes a first leg  312  that includes an upper end  314  and a lower end  316 , a second leg  318  that includes an upper end  320  and a lower end  322 , and a support beam  323  that, in the exemplary embodiment, extends between upper end  314  and upper end  320 . In the exemplary embodiment, reaction bridge  305  is coupled to casing section  202  via mounting plate  214 . More specifically, and in the exemplary embodiment, lower end  316  is coupled to first horizontal flange  206  via mounting plate  214 , and lower end  322  is coupled to second horizontal flange  208  via mounting plate  214 , such that reaction bridge  305  extends over casing section  202  and rotor  110 . Moreover, in the exemplary embodiment, segment removal system  300  includes a pair of multi-position slides  324  that are each coupled to first leg upper end  314  and a pair of multi-position slides  324  that are coupled to second leg upper end  320 . Multi-position slides  324  each include a plurality of placement holes  326 , as described in more detail herein. Alternatively, segment removal system  300  may include any number of multi-position slides  324  that enables segment removal system  300  to function as described herein. In operation, reaction bridge  305  is movable along a length L 1  of mounting plate  214 , and is coupled to mounting plate  214  using holes  216  and at least one fastening mechanism (not shown). 
     Referring to  FIGS. 8 and 9 ,  FIG. 8  is an elevation view of compressor  200  and segment removal system  300 , with an exemplary force device  400  installed.  FIG. 9  is a side perspective view of compressor  200  and segment removal system  300  with force device  400  installed. In the exemplary embodiment, force device  400  includes an actuator  410  and an engaging rod  420  that extends therefrom. Rod  420  has a defined stoke length L 2 . In the exemplary embodiment, actuator  410  is a 75-ton hydraulic ram and force device has a 13 inch stroke length. Alternatively, force device  400  maybe any device that enables segment removal system  300  to function as described herein. Force device  400  is coupled to reaction bridge  305  via multi-position slide  324 . Specifically, multi-position slide  324  is configured, via placement holes  326 , to enable force device  400  to be positioned at a various positions along a length L 3  along multi-position slide  324  depending on a location of reaction bridge  305  relative to mounting plate  214 . 
     In operation, and in the exemplary embodiment, actuator  410  forces engaging rod  420  against segment outer end  240  (see  FIGS. 4 and 5 ) to facilitate removing segment  212  from channel  210 . More specifically, in the exemplary embodiment, engaging rod  420  induces pressure substantially tangentially against segment end  240  for a stroke length L 2 . Upon achieving the maximum stroke length L2, engaging rod  420  is retracted and a mock segment  430  is inserted into segment  212  to enable force device  400  to maintain contact with the segment end  240  beyond the maximum stroke length L2. In the exemplary embodiment, actuator  410  then pushes engaging rod  420  to re-engage segment end  240  via mock segment  430 . In the exemplary embodiment, force is applied against segment end  240  until segment  212  is fully removed from channel  210 . Alternatively, force is applied to segment end  240  until segment  210  reaches a position where it may be pulled from channel  210 , as described herein. 
     Referring to  FIGS. 10 and 11 ,  FIG. 10  is an elevation view of compressor  200  and segment removal system  300 , with an exemplary force device  500  installed.  FIG. 11  is a side perspective view of compressor  200  and segment removal system  300  with force device  500  installed. In the exemplary embodiment, force device  500  includes an actuator  510 , a clevis assembly  512  and an engaging rod assembly  514  that extends therebetween. In the exemplary embodiment, actuator  510  is coupled to reaction bridge  305  and multi-position slide  324  via a pivot cradle assembly  516 . Actuator  510  includes an enclosed axial channel (not shown). In the exemplary embodiment, engaging rod assembly  514  includes a threaded rod  522  that includes a first end  524  and an opposite second end  526  and is coupled to actuator such that first end  524  extends through axial chamber (not shown) of actuator  510  and extends a length L 4  outward from actuator  510 . In the exemplary embodiment, attachment rod second end  526  is threadedly coupled to clevis assembly  512 , as described in detail herein. Moreover, in the exemplary embodiment, actuator  510  is a 30 ton hydraulic actuator. Alternatively, actuator  510  may be any pneumatic, mechanical or electrical actuator that enables segment removal system to function as described herein. 
     Referring to  FIGS. 12 and 13 ,  FIG. 12  is an exploded view of an exemplary clevis assembly  512 .  FIG. 13  is a partial elevation view of exemplary casing section  202  with exemplary clevis assembly  512  coupled to segment outer end  240 . In the exemplary embodiment, clevis assembly  512  includes a first component  602 , a second component  604  and a joint component  606 . First component  602  includes a first end  608  and a second end  610  and is threadedly coupled to attachment rod second end  526  via threaded hole  612 . In the exemplary embodiment, first component second end  610  includes a T-shaped extension  614  and mating hole  616  defined therein. 
     In the exemplary embodiment, second component  604  has a substantially rectangular cross-sectional profile and includes a first side  630 , a second side  632 , a third side  634  that is opposite first side  630 . Moreover, component  604  also includes a forth side  636  that is opposite second side  632 , and an upper portion  640  that includes an open channel  642  passing from second side  632  to fourth side  636 . Upper portion first side  630  and third side  634  each include a mating hole  644  defined therein that are aligned such that mating hole  644  extends through channel  642 . In the exemplary embodiment, channel  642  includes a lower surface  646  and second component  604  includes a bottom surface  648 . Three bolt holes  650  extend between channel lower surface  646  and bottom surface  648 . Bolt holes  650  enable second component  604  to be coupled to blade segment  212  to facilitate removing segment  212  from stator channels  210 . 
     Joint component  606 , in the exemplary embodiment, includes a cubic portion  660  and an extension portion  662 . Cubic portion  660  includes a first side  664 , a second side  666 , a third side  668  that is opposite first side  664 , and a fourth side  670  that is opposite second side  666 . Portion  660  also includes a mating hole  672  that extends from second side  666  to fourth side  670 . Cubic portion  660  includes an open channel  674  that extends from first side  664  to third side  668 , and that is sized and oriented to receive first component extension  614  such that first component mating hole  616  and cubic portion mating hole  672  are aligned and receive a first clevis pin  675  when assembled, such that components  602  and  606  are rotatable about pin  675 . Extension portion  662  includes a hole  676  defined therein. Second component open channel  642  is sized and oriented to receive joint component extension portion  662  and is oriented such that second component mating hole  644  and extension portion mating hole  676  are aligned to receive a second clevis pin  678  when assembled, such that components  604  and  606  are rotatable about pin  678 . In the exemplary embodiment, first clevis pin  675  and second clevis pin  678  are substantially perpendicular to each other. 
       FIG. 14  is an elevation view of actuator  510  with pivot cradle assembly  700 . Reaction bridge  702  includes a forward support  704  and rear support  706  that is substantially parallel to support  704 . A multi-position slide  708  is coupled to forward support  704  and to rear support  706 . A trunnion assembly  710  is coupled to a top surface  712  of each multi-position slide  708 . Trunnion assembly  710  includes a first support  720 , a second support  722  and a rotatable support  724  coupled therebetween. Rotatable support  724  includes a first side  726 , a second side  728 , a third side  730  that is opposite first side  726 , a fourth side  732  that is opposite second side  728 , a top surface  734  and a bottom surface  736 . In the exemplary embodiment, a trunnion pin (not shown) extends substantially perpendicularly outward from both second side  728  and fourth side  732 . First support  720  has a hole  738  defined therein that is sized to receive a second side trunnion pin (not shown). Similarly, second support  722  has a hole defined therein that is sized to receive fourth side trunnion pin (not shown). 
     Rotatable support  724  includes a channel (not shown) defined therein that extends from top surface  734  to bottom surface  736  and that is sized and oriented to receive threaded rod  522 . Actuator  510  is positioned against rotatable member top surface  734  such that actuator axial channel (not shown) and rotatable support channel (not shown) are substantially aligned. Threaded rod  522  is positioned within the actuator axial channel and the rotatable support channel such that a length extends L 3  from actuator  510 . An encapsulating bushing assembly  800  is coupled to the length L 3  of exposed rod  522 . 
     During operation, actuator  510  exerts a pulling force to threaded rod  522 , that, when coupled to segment outer end  240 , facilitates the removal of segment  212  from channel  210 . Encapsulating bushing assembly  800  is positioned upon the length of exposed threaded rod to facilitate preventing threaded rod  522  from disconnected from the system, should thread rod  522  experience a structural failure during operations. Pivot cradle assembly  700  and trunnion assembly  710  facilitate rotation of actuator  510  during operations. 
     The above-described methods and system provide a cost-effective and reliable means to facilitate the disassembly of gas turbine engine components. Specifically, stator vane segment removal may be accomplished without removing the rotor assembly from the engine. As such, system outage duration due to repairs may be significantly reduced. Additionally, the segment removal system described herein facilitates reducing segment removal time by enabling a user to quickly change from a segment pushing device to a segment pulling device. 
     Exemplary embodiments of a process and system for disassembling a machine, particularly removing stator vane sections from a gas turbine engine is described above in detail. The process and system are not limited to the specific embodiments described herein, but rather, steps of the process and components of the system may be utilized independently and separately from other steps and components described herein. 
     While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.