Abstract:
This disclosure describes embodiments of an apparatus for use to extract a rotor from a generator. The apparatus can include a central mount element that secures to the end of the rotor. A pair of support members coupled to the sides of the central mount element. The support members can include a load bearing element that permits travel of the apparatus on a surface, e.g., a platform proximate to the turbine generator. During implementation, the apparatus is configured to direct pulling forces along the center axis of the rotor to restrict movement of the rotor and, in particular, limit rotation of the rotor that can result in inadvertent contact with the stator or other parts of the generator.

Description:
BACKGROUND OF THE INVENTION 
     The subject matter disclosed herein relates to generators and repair of the same and, in particular, to an apparatus that restricts movement of a rotor (or “field generator”) during extraction of the rotor, e.g., from a gas turbine generator. 
     Generators include a stator and a rotor that rotates relative to the stator to generate electricity. Technicians often need to extract the rotor from the stator to perform repair and maintenance on the generator. In conventional practice, this task requires overhead cranes and rigging in combination with certain implements (e.g., field support shoes and core skid pans) to guide and support the rotor during extraction from the generator. The configuration of the rigging, however, is not typically standardized, but rather the construction of the generator and the experience and know-how of the technicians that are to complete the repairs and maintenance ultimately determine the way the rigging secures to the rotor. 
     The rigging often engages the rotor at points that are radially outside of the centerline of the rotor. This engagement directs the pulling forces, which extract the rotor from the stator, off-center from the centerline of the rotor. The resulting offset may cause the rotor to become unstable during extraction and, in some cases, prone to movement (e.g., rolling). Such movement can shift the weight of the rotor off of the field support shoes that are meant to prevent contact between the rotor and the stator or other components of the generator. In some cases, the resulting moment of inertia can cause inadvertent contact between the rotor and the stator, which can lead to extensive damage as well as substantial repair costs and machine downtime. 
     The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. 
     BRIEF DESCRIPTION OF THE INVENTION 
     This disclosure describes embodiments of an apparatus for use to extract the rotor from a generator that restricts movement of the rotor during extraction across a wide range of configurations and installations of generators. The apparatus can include a central mount element that secures to the end of the rotor. A pair of support members coupled to the sides of the central mount element. The support members can include a load bearing element that permits travel on a surface, e.g., a platform proximate to the generator. An advantage that practice of one or more embodiments of the present disclosure is to direct forces along the centerline of the rotor to facilitate straight and level travel of the rotor during extraction. 
     The present disclosure describes, in one embodiment, an apparatus for extracting a rotor from a generator. The apparatus comprises a central mount element comprising a center pull plate with a center axis and a force coupler for receiving a load. The force coupler secures to the center pull plate and aligns with the center axis. The apparatus also comprises a first support member and a second support member coupled to, respectively, a first side and a second side of the central mount element. The first support member and the second support member have a top end and a bottom end, wherein the center pull plate is located proximate to the top end when secured to the rotor. The apparatus further comprises load bearing elements disposed on the bottom ends of the first support member and the second support member. 
     The present disclosure also describes, in one embodiment, an apparatus for extracting a rotor from a generator. The apparatus comprises a center pull plate that comprises a first plate and a second plate that couples with the first plate. The apparatus also comprises a pair of support members coupled to the center pull plate, one support member on a first side of the center pull plate and one support member on a second side of the center pull plate. The support members comprise vertical upright elements that have a top end and a bottom end and an adapter element that translates vertically on the vertical upright element. The apparatus further comprises a plurality of rolling elements disposed on the bottom ends of the vertical upright elements. 
     The present disclosure further describes, in one embodiment, an apparatus for extracting a rotor from a generator. The apparatus comprises a welded frame with a first side and a second side. The welded frame comprises a plurality of frame members and a plate with a center axis disposed on the centerline. The apparatus further comprises a first support member and a second support member slidably engaging at least one of the frame members. The first support member and the second support member are located, respectively, on the first side and the second side of the welded frame. The apparatus further comprises load bearing elements disposed on bottom ends of the first support member and the second support member. 
     This brief description of the invention is intended only to provide a brief overview of the subject matter disclosed herein according to one or more illustrative embodiments, and does not serve as a guide to interpreting the claims or to define or limit the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce an illustrative selection of concepts in a simplified form that are further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which: 
         FIG. 1  depicts a perspective view of an exemplary embodiment of an apparatus for removing a rotor from a generator; 
         FIG. 2  depicts a front view of the apparatus of  FIG. 1 ; 
         FIG. 3  depicts a perspective view of another exemplary embodiment of an apparatus for removing a rotor from a generator; 
         FIG. 4  depicts a perspective view of the apparatus of  FIG. 3  in position next to a generator; 
         FIG. 5  depicts a front view of yet another exemplary embodiment of an apparatus for removing a rotor from a generator; 
         FIG. 6  depicts a side, cross-section view of the apparatus of  FIG. 5 ; 
         FIG. 7  depicts a side view of an adapter plate for use in an apparatus for removing a rotor from a generator, e.g., the apparatus of  FIGS. 5 and 6 ; 
         FIG. 8  depicts a front view of the adapter plate of  FIG. 7 ; and 
         FIG. 9  depicts a front view of a primary plate for use in an apparatus for removing a rotor from a generator, e.g., the apparatus of  FIGS. 5 and 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Broadly, the discussion below focuses on embodiments of an apparatus that secures to an end of a rotor found in a generator (e.g., a turbine generator). When in position, the apparatus directs forces (e.g., pulling forces) along the centerline of the rotor. These forces move the rotor during repair and maintenance of the generator. Configurations of the apparatus, however, eliminate the need for extensive rigging and other implements that couple the rotor to an overhead gantry and/or crane system. As discussed more below, for example, designs for the apparatus maintain the orientation of the rotor during extraction to promote straight and level travel of the rotor and, effectively, reduce the likelihood of movement (e.g., rolling) of the rotor in response to changes in moment of inertia during extraction. 
       FIG. 1  illustrates an exemplary embodiment of an apparatus  100  in position next to a generator  102 . The apparatus  100  resides on a structural platform  104  that abuts the generator  102 . In one example, the generator  102  has a stator  106  and a rotor  108  with a rotor axis  110 . The rotor  108  has a driver end  112  and a collector end  114 . On the driver end  112 , the rotor  108  can mate with a gas or steam turbine and/or other power generating equipment that rotates the rotor  108  relative to the stator  106 . 
     During repair and/or maintenance, technicians can secure the apparatus  100  to the rotor  108  proximate to the collector end  114 . Examples of the apparatus  100  transmit a force (e.g., a pulling force F IN  and/or a pushing force F OUT ) to the rotor  108  along the rotor axis  110 . The forces F IN  and F OUT  change the position of the rotor  108  in relation to the stator  106 . For example, application of the force F as a pulling force F OUT  can extract the rotor  108  from the stator  106  to expose portions of the generator  102  for technicians to perform repair and maintenance tasks. After the requisite tasks are complete, application of the force F as a pushing force F IN  returns the rotor  108  back into position inside of the stator  106 . 
       FIG. 2  illustrates a front view of the exemplary apparatus  100 . In the example of  FIG. 2 , the apparatus  100  has a central mount element  116  with a first side  118 , a second side  120 , and a center line  122  disposed therebetween. The central mount element  116  supports a rotor mount  124  with a center axis  126 . The apparatus  100  also has a plurality of support members (e.g., a first support member  128  and a second support member  130 ) on the first side  118  and the second side  120  of the central mount element  116 . The support members  128 ,  130  have a top end  132  and a bottom end  134  and are spaced apart from the center line  122 . The support members  128 ,  130  include load bearing elements (e.g., a first load bearing element  136  and a second load bearing element  138 ). Examples of the load bearing elements  136 ,  138  incorporate devices (e.g., castors, wheels, sliders, bearings, etc.) that support loads and facilitate movement of the apparatus  100 , e.g., over surfaces of platform  104 . 
     In one embodiment, the apparatus  100  has a plurality of adjustments (e.g., a first adjustment  140  and a second adjustment  142 ). The adjustments  140 ,  142  allow changes to the position of certain elements and members of the apparatus  100 . For example, the first adjustment  140  changes the horizontal position of the support members  128 ,  130  relative to the center line  118 . This feature can increase and decrease the spacing of the support members  128 ,  130  relative to one another, e.g., to fit the apparatus  100  to areas on the support platform  104  and/or to balance loading and prevent rolling of the rotor  108  of  FIG. 1 . On the other hand, the second adjustment  142  changes the vertical position of the central mount element  116  relative to the structural platform  104 . This feature is useful to locate mounting features on the rotor mount  120  with corresponding mounting features on the rotor  108  of  FIG. 1 . 
     With reference to both  FIGS. 1 and 2 , securing of the central mount element  116  to the rotor  108  may utilize fasteners (e.g., bolts) that engage the rotor mount  120  to the rotor  108 . Exemplary fasteners can carry loads of magnitude necessary to allow extraction of the rotor  108  from the generator  102 . In one example, mounting the rotor mount  120  to the rotor  108  aligns the center axis  126  with the rotor axis  112 . This configuration directs pulling forces along the rotor axis  112  to promote straight and level extraction of the rotor  108  from the generator  102 . 
     In one embodiment, technicians can apply the pulling force F OUT  directly to the central mount element  116  and, in one particular construction, directly on the rotor mount  124 . The central mount element  116  may be equipped, for example, to allow the technicians to couple peripheral equipment to the apparatus  100 . Examples of these peripheral devices include winches, pulleys, come-alongs, and like devices that can generate forces sufficient to move the rotor  108  from its position in the generator  102 . 
       FIG. 3  illustrates another exemplary embodiment of an apparatus  200  for removing a rotor from a generator. In  FIG. 3 , the central mount element  216  includes a frame  244  with one or more frame members  246 . The rotor mount  220  includes a center pull plate  248  with a plurality of openings  250  and a force coupler  252  (e.g., a hoist ring, a hitch, etc.). The support members  228 ,  230  include vertical upright elements (e.g., a first vertical upright element  254  and a second vertical upright element  256 ) and adapter elements (e.g., a first adapter element  258  and a second adapter element  260 ). The adapter elements  258 ,  260  can transit vertically on the vertical upright elements  254 ,  256  and horizontally on the frame members  246 . The load bearing elements  236 ,  238  have sets of rolling elements (e.g., a first set  262  and a second set  264 ) disposed on foot elements (e.g., a first foot element  266  and a second foot element  268 ) that couple proximate to the bottom end  234  of the vertical upright elements  254 ,  256  on the support members  228 ,  230 . 
     In one embodiment, the apparatus  200  also includes a plurality of releasable fasteners  270 , which couple the elements of the apparatus  200  together. Examples of the releasable fasteners  270  include bolts and screws as well as pull-pins and related “quick-release” devices that can penetrate through openings in multiple elements (e.g., the frame members  246  and the adapter elements  258 ,  260 ). This feature of the apparatus  200  facilitates adjustment, e.g., of the horizontal position of the adapter elements  258 ,  260  on the frame members  246  and the vertical position of the adapter elements  258 ,  260  on the vertical upright elements  254 ,  256 . For example, the frame members  246  may include frame openings (e.g., holes) at locations spaced apart a defined increments relative to center pull plate  248  (or centerline  118  of  FIG. 2 ). The position of the adapter elements  258 ,  260  can be changed relative to the center pull plate  248  by aligning openings (e.g., holes) on the adapter elements  258 ,  260  with the frame openings and inserting the releasable fasteners  270 . 
     Moreover, use of releasable fasteners  270  allows construction of the apparatus  200  as a plurality of piece parts. Such construction alleviates issues with shipping and transport of the apparatus  200  into position at the generator (e.g., generator  102  of FIG.  1 ). For example, the apparatus  200  can ship in an unassembled form, which has a form factor that is conducive to shipment in one or more boxes, for the technicians to assemble the pieces together on site. 
     Construction of the apparatus  200  can utilize manufacturing techniques that are known to provide secure connection of elements and meet the desired strength characteristics for equipment of this type. For example, the frame  244 , the frame members  246 , and the adapter elements  258 ,  260  can take the form of one or more weldments (e.g., a welded frame) and/or like construction that use welds to secure one or more elements (e.g., the center pull plate  248  and the frame members  246 ) together. This disclosure contemplates materials that include metal (e.g., steel) tubes and plates of selected dimensions (e.g., thickness) and arrangements deemed appropriate for purposes of carrying loads. 
       FIG. 4  illustrates the apparatus  200  in position on the generator  202 . In the example of  FIG. 4 , the apparatus  200  includes a plurality of fasteners  272 , which penetrate the openings  250  to affix the center pull plate  248  with the rotor  208 . A peripheral device  274  couples with the force coupler  252 . The rolling elements  262 ,  264  travel in a set of channels  276  that mount to the structural platform  204 . Examples of the channels  276  can comprise U-channel steel members and/or I-beams. The structural platform  204  may incorporate the channels  276 , e.g., for purposes of carrying an overhead crane that is used during maintenance and repair of the generator  202 . In one example, the location of the channels  276  relative to the generator  202  and/or relative to one another may require horizontal adjustment (e.g., first adjustment  140  of  FIG. 1 ) of the adapter elements  258 ,  260  to position the rolling elements  262 ,  264  in the channels  272 . 
       FIGS. 5 and 6  illustrate another exemplary embodiment of an apparatus  300  that can facilitate extraction of a rotor from a generator.  FIG. 5  shows a front view of the apparatus  300  in which the center pull plate  348  is split into two separate pieces that includes an adapter plate  378  and a primary plate  380 . In one example, the primary plate  380  is itself integrated (e.g., welded) as part of the frame  344 . The apparatus  300  utilizes a first set  382  of fasteners (e.g., bolts, screws, etc.) to secure the adapter plate  378  in position on the rotor  308  ( FIG. 6 ). In one example, the apparatus  300  also utilizes a second set  384  of fasteners (e.g., bolts, screws, etc.), which secure the adapter plate  378  to the primary plate  380 . This configuration of the center pull plate  348  allows the apparatus  300  to engage the rotor  308  ( FIG. 6 ) independent of the orientation of the rotor  308  ( FIG. 6 ) at the time of repair. 
     For example, as best shown in the cross-section of  FIG. 6 , during installation, technicians can first secure the adapter plate  378  using the first set  382  of fasteners onto the exposed end of the rotor  308 . Next, technicians can move the apparatus  300  to position the primary plate  380  proximate to the adapter plate  378 . Using the second set  384  of fasteners, technicians can secure the adapter plate  378  to the primary plate  380 . In the example of  FIG. 6 , the force coupler  352  threads into the adapter plate  378 . Once the apparatus  300  is properly secured to the rotor  308 , a force (e.g., a pulling force F OUT  and/or a pushing force F IN ) can be applied to the force coupler  352  and/or the apparatus  300  generally. 
       FIGS. 7 and 8  depict an example of an adapter plate  400  for use as the adapter plate  378  ( FIGS. 5 and 6 ). As shown in the side view of  FIG. 7 , the adapter plate  400  includes an adapter body  402  with a first side  404  and a second side  406  that abuts the rotor (e.g., rotor  308  of  FIG. 6 ) when the adapter plate  400  is installed thereon. In one example, the adapter plate  400  includes a stepped profile with an inner step  408  and an outer step  410 . 
       FIG. 8  shows a front view of the adapter plate  400  of  FIG. 7 . As shown in the front view, the adapter plate  400  has a central threaded aperture  412 . The stepped profile takes the form of a pair of annular disc shapes (e.g., a first annular disc  414  and a second annular disc  416 ) and a square or rectangular shape  420  that forms the second side  406  ( FIG. 7 ). The adapter plate  400  also has a first array  422  of openings  424  that circumscribe the central threaded aperture  412  and a second array  426  of threaded openings  428  that are radially outside the first array  422  as measured from the central threaded aperture  412 . 
       FIG. 9  shows an example of a primary plate  500  (e.g., for use as the primary plate  380  of  FIGS. 5 and 6 ). The primary plate  500  includes a plate body  502  and a central opening  504  that extends therethrough. The plate body  502  also includes a third array  506  of openings  508  that circumscribe annularly about the central opening  504 . 
     With reference to the examples of  FIGS. 7 ,  8 , and  9 , features of the adapter plate  400  and the primary plate  500  allow for appropriate fit and function of these two elements in combination, e.g., to form the center pull plate  348  of  FIGS. 5 and 6 . In one example, the central opening  504  is sized to receive at least a portion of the adapter plate  400 . For example, the diameter of the central opening  504  is larger than the outer diameter of the second annular disc  416 . These dimensions allow the outer step  410  of the adapter plate  400  to abut the surface of the primary plate  500 . The adapter plate  400  can be secured to the primary plate with fasteners that extend through the primary plate  500  (e.g., through the openings  508  of  FIG. 9 ) and into the adapter plate  400  (e.g., into threaded openings  438  of  FIG. 8 ). 
     Examples of the openings in the adapter plate  400  and the primary plate  500  include cylindrical holes as well as elongated slots. The cylindrical holes can, as set forth above, include threads of varying characteristics (e.g., pitch) to receive fasteners that secure the adapter plate  400  to the primary plate  500 . The elongated slots are useful to accommodate for tolerances, misalignment, and differences in orientation that technicians may encounter during installation of embodiments of the apparatus disclosed herein. By using elongated slots and/or comparably configured features in the adapter plate  400  and the primary plate  500  (and the central pull plate in general), designs for the apparatus (e.g., the apparatus  100 ,  200 ,  300  of  FIGS. 1 ,  2 ,  3 ,  4 ,  5 , and  6 ) simplify installation on the rotor and/or generator. The slots provide a larger target opening, as compared to a cylindrical hole. The larger opening accommodates misalignment, which may prevent fasteners from appropriately securing the apparatus to one or more of the rotor, the primary plate  500 , and the adapter plate  400 . 
     As used herein, an element or function recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or functions, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the claimed invention should not be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.