Abstract:
A method of installing a rotor assembly in a generator stator including a central bore is provided. The method includes coupling at least one of a first rotor section and a second rotor section of the rotor assembly to a conveyor such that at least a portion of the rotor assembly is supported by the conveyor. The method also includes moving the rotor assembly into position within the stator bore using the conveyor.

Description:
BACKGROUND OF THE INVENTION 
   This invention relates generally to generators, and more particularly, to methods and apparatus for installation and removal of a generator rotor assembly. 
   During at least some known methods of installation and removal of a rotor assembly within a generator stator bore, the rotor assembly is slid along a track using straps attached to the rotor assembly. However, sliding the rotor assembly may subject the core of the rotor assembly to the full weight of the rotor assembly. 
   At least some known field assemblies include a core that is fabricated from steel and copper that provides enough strength to the core to enable the core to withstand the weight of the rotor sections. However, other known rotor assembly cores are fabricated from materials that generally lack the material strength to withstand the weight of the rotor sections. Accordingly, such rotor assembly cores limit the installation and removal methods that may be used. 
   Generally, known methods of installing and removing a rotor assembly require a tremendous amount of effort and manipulation on the part of the technicians. Specifically, known methods may require the rotor assembly to be manipulated at several different angles with respect to the stator bore. Moreover, known methods may require the rotor assembly to be repeatedly manipulated and/or repositioned several times before it can be installed or removed. 
   BRIEF DESCRIPTION OF THE INVENTION 
   In one aspect, a method of installing a rotor assembly in a generator stator including a central bore is provided. The method includes coupling at least one of a first rotor section and a second rotor section of the rotor assembly to a conveyor such that at least a portion of the rotor assembly is supported by the conveyor. The method also includes moving the rotor assembly into position within the stator bore using the conveyor. 
   In a further aspect, a method of removing a rotor assembly from a generator stator including a central bore is provided. The method includes coupling at least one of a first rotor section and a second rotor section of the rotor assembly to a conveyor such that at least a portion of the weight of the rotor assembly is supported by the conveyor. The method also includes removing the rotor assembly from the stator bore using the conveyor. 
   In another aspect, a system to facilitate installation and removal of a rotor assembly of a generator stator is provided. The system includes a support frame assembly and a conveyor coupled to the support frame assembly and configured to couple to a first rotor section and a second rotor section of the rotor assembly such that at least a portion of the rotor assembly is supported by the conveyor. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an assembly system for use in installing and removing a generator stator rotor assembly; 
       FIG. 2  is a side view of the assembly system shown in  FIG. 1 ; 
       FIG. 3  is a side view of the assembly system shown in  FIG. 2  and coupled to a rotor assembly prepared for insertion into a stator bore; 
       FIG. 4  is a side view of the rotor assembly shown in  FIG. 3 , and initially inserted into the stator bore; 
       FIG. 5  is a side view of the rotor assembly shown in  FIG. 3  and inserted through the stator bore such that an outer stub clamp shown in  FIG. 3  is accessible at a gear end of the generator stator; 
       FIG. 6  is a side view of the rotor assembly shown in  FIG. 3  and inserted through the stator bore such that a first rotor is substantially flush with the gear shown in  FIG. 5 ; 
       FIG. 7  is a side view of the rotor assembly shown in  FIG. 3  and coupled to the gear; 
       FIG. 8  is a side view of the rotor assembly shown in  FIG. 7  and being prepared for removal from the stator bore; 
       FIG. 9  is a side view of the rotor assembly shown in  FIG. 8  and disconnected from the gear; 
       FIG. 10  is a side view of the rotor assembly shown in  FIG. 8  and positioned such that the rotor assembly shown in  FIG. 8  is supported by a shoe and a trolley; 
       FIG. 11  is a side view of the rotor assembly shown in  FIG. 8  and positioned at an entry end of the stator bore; and 
       FIG. 12  is a side view of the rotor assembly shown in  FIG. 8  and removed from the generator stator. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  is a perspective view of an assembly system  100  for use in installing and removing a generator rotor assembly (not shown in  FIG. 1 ) through a generator stator (not shown in  FIG. 1 ).  FIG. 2  is a side view of assembly system  100 . Assembly system  100  is configured to position the rotor assembly at an entry end of the generator stator. Specifically, assembly system  100  facilitates aligning the rotor assembly within and with respect to a bore defined in the generator stator. Assembly system  100  includes a support assembly  120  and a support rail  140 . Support assembly  120  includes a plurality of supports  160  coupled together in a framework  170 . Supports  160  extend generally vertically. Specifically, framework  170  includes a pair of opposed lateral support members  174  that extend along a full length of assembly system  100  and that are coupled to supports  160 . Framework  170  also includes a plurality of auxiliary support members  178  that are arranged in X-orientations between adjacent vertical supports  160 . The combination of auxiliary support members  178  and pairs of vertical supports  160  form leg assemblies  180  for assembly system  100 . Each leg assembly  180  also includes a base  190  extending substantially horizontally across a bottom end  194  of vertical supports  160 . In the exemplary embodiment support assembly  120  includes four leg assemblies  180 . In other embodiments, support assembly  120  may include more or less than four leg assemblies  180 . 
   In the exemplary embodiment, each vertical support  160  includes a first portion  200  and a second portion  210 . Each first portion  200  is hollow and is telescopically coupled to second portion  210  such that second portion  210  is slidably received within first portion  200 . As such, second portion  210  is slidable within first portion  200  such that a height  212  of support assembly  120 , measured from base  190  to an outer tip  214  of vertical support  160 , can be adjusted. In the exemplary embodiment, a plurality of fastening mechanisms  216  are used to set height  212  of assembly system  100 . In alternative embodiments, vertical supports  160  can be adjusted using any of hydraulically adjustable supports, screw actuators, and/or any other adjustable supports that enable height  212  of system  100  to be adjusted as described herein. 
   In the exemplary embodiment, leg assemblies  180  are coupled in a rectangular orientation such that a first pair of leg assemblies  180  define a front section  220  of assembly system  100 , and such that a second pair of leg assemblies  180  define a rear section  230  of assembly system  100 . A plurality of top supports  240  extend between, and are coupled to, each pair of leg assemblies  180 . Support rail  140  is also coupled to top supports  240  such that rail  140  extends through, and is centered within, assembly system  100  and extends from rear section  230  to front section  220 . Assembly system  100  is positioned such that rail  140  and lateral support members  174  extend outward from legs  180  towards the entry end of the generator stator bore. 
   Assembly system  100  includes a conveyor  260  that is coupled to rail  140  such that conveyor  260  is moveable either towards, or away from, the generator stator bore along a full length of rail  140 . In the exemplary embodiment, conveyor  260  includes a pair of trolleys  262  and  264  that are each coupled to rail  140  by a pair of wheels  268 . In an alternative embodiment, conveyor  260  may be, but is not limited to being, a wheel assembly, a slide assembly, a rack and pinion assembly, or any other assembly that enables conveyor  260  to function as described herein. In a further embodiment, conveyor  260  may be, but is not limited to being, one of any combination of a wheel assembly, a slide assembly, a rack and pinion assembly, and/or any other assembly that enables conveyor  260  to function as described herein. 
   Conveyor  260  includes an attachment mechanism  280  that is suspended from trolleys  262  and  264  and is configured to couple a rotor assembly (not shown in  FIG. 2 ) to assembly system  100  such that the rotor assembly is suspended from rail  140 . Specifically, the rotor assembly is coupled to conveyors  260  such that it is suspended within assembly system  100  between opposing pairs of legs  180 . More specifically, when coupled to assembly system  100 , the rotor assembly is suspended below rail  140  a distance off the ground and is substantially centered between lateral supports  174 . Lateral supports  174  provide structural support to assembly system  100  such that swaying of the rotor assembly within assembly system  100  when it is suspended from rail  140  is facilitated to be prevented. 
   Before use, vertical supports  160  are adjusted to facilitate positioning the rotor assembly with respect to the generator stator bore. The rotor assembly is then coupled to conveyor  260 . Through conveyor  260 , the rotor assembly is moved into position within the stator bore. Furthermore, the alignment of the rotor assembly may be adjusted at any time by adjusting a height of vertical supports  160 . 
     FIGS. 3-7  illustrate subsequent stages of installation of a rotor assembly  300  into a bore  340  of a generator stator  320  using assembly system  100 . For clarity, support assembly  120  is not illustrated in  FIGS. 3-7 . Specifically,  FIG. 3  is a side view of rotor assembly  300  prepared to be inserted into stator bore  340 ,  FIG. 4  is a side view of an initial insertion of rotor assembly  300  within stator bore  340 , and  FIG. 5  is a side view of subsequent installation of rotor assembly  300  within stator bore  340 , and positioned such that an outer stub clamp  520  is accessible at a gear end  640  of generator stator  320 .  FIG. 6  illustrates rotor assembly  300  within stator bore  340  and positioned such that a first rotor  380  is substantially flush against a generator gear  700 , and  FIG. 7  is a side view of rotor assembly  300  coupled to generator gear  700 . 
   Assembly system  100  supports rotor assembly  300  such that no pressure or weight is induced to a rotor assembly core  360 . Specifically, rotor assembly core  360  includes a first rotor  380  and a second rotor  400 . Core  360  is coupled to assembly system  100  such that rotor assembly  300  is suspended from rail  140  and is substantially centered within assembly system  100 . More specifically, when suspended within assembly system  100 , first rotor  380  is coupled to a first clamp  420  suspended from first trolley  262 , and second rotor  400  is coupled to a second clamp  460  suspended from second trolley  264 . In this orientation, rotor assembly  300  can be moved into stator bore  340  via trolleys  262  and  264 . 
   An inner stub clamp or stub shaft  500  and an outer stub clamp or stub shaft  520  extend from first rotor  380 . Inner stub clamp  500  and outer stub clamp  520  provide additional coupling points for assembly system  100  that facilitate positioning of rotor assembly  300  within stator bore  340 . Outer stub clamp  520  includes a shoe  540  that extends downward therefrom, and a tension member  560  that extends axially therefrom. In the exemplary embodiment, tension member  560  is a tow cable. Alternatively, tension member  560  may be, but is not limited to being, a tension rod, a hydraulic shaft, or any other device that facilitates positioning rotor assembly  300  as described herein. 
   A second shoe  570  extends outward from first rotor  380 . Second shoe  570  facilitates supporting rotor assembly  300  as rotor assembly  300  is inserted within stator bore  340 . In addition, inner stub clamp  500  includes a stabilizer  580  coupled thereto. A second stabilizer  581  is coupled to second rotor section  400  via a third clamp  590 . Stabilizers  580  and  581  contact lateral support members  174  to facilitate preventing swaying of rotor assembly  300  such that rotor assembly  300  remains substantially centered within assembly system  100 . 
   Before inserting rotor assembly  300  within bore  340 , a skid pan (not shown) is positioned substantially flush against an outer surface  600  defining bore  340 , and vertical supports  160  are adjusted to facilitate aligning rotor assembly  300  with respect to bore  340 . Trolleys  262  and  264  are translated along rail  140  while tension applied to tension member  560  causes rotor assembly  300  to move towards bore  340 . During movement, swaying of rotor assembly  300  is prevented by stabilizers  580  and  581 , and by lateral supports  174 . Rotor assembly  300  is then moved until shoe  540  is positioned above the skid pan. Vertical supports  160  are adjusted to position shoe  540  substantially flush against the skid pan. As such, rotor assembly  300  is supported by both trolleys  262  and  264 , and by shoe  540 . 
   Rotor assembly  300  is then also temporarily supported by a support member  610  positioned under second rotor section  400 . Both trolleys  262  and  264  are then uncoupled from rotor assembly  300 . Specifically, trolley  264  and clamp  460  are uncoupled from second rotor  400 , and trolley  262  and clamp  420  are uncoupled from first rotor section  380 . Trolley  264  is repositioned at an end  620  of rail  140 , and trolley  262  is repositioned from a first position  624 , aligned with first rotor  380 , to a second position  628 , aligned with second rotor  400 . Trolley  262  is then coupled to second rotor  400  via third clamp  590 . Stabilizer  581  is also uncoupled from inner stub clamp  500  to enable rotor assembly  300  to be inserted within bore  340 . 
   Support member  610  is removed from beneath second rotor  400  such that rotor assembly  300  is supported by trolley  262  and by shoe  540 . Rotor assembly core  360  is moved into bore  340  by sliding trolley  262  and through tension applied to tension member  560 . As core  360  approaches bore  340  a measurement gauge (not shown) is used to ensure an adequate circumferential gap  636  is defined between a circumference of core  360  and bore surface  600 . Specifically, the gauge is used to ensure that core  360  is substantially centered within stator bore  340 . If necessary, assembly system  100  is adjusted to reposition core  360  relative to bore  340 . During installation of core  360  within bore  340  adjustments may be made to assembly system  100  to prevent core  360  from contacting bore  340 . 
   During subsequent insertion, tension member  560  and shoe  540  are removed. During this phase of installation, rotor assembly  300  is supported by second shoe  570  and trolley  262  via third clamp  590 . A second conveyor  680  is located at a gear end  640  of generator stator  320  and is coupled to outer stub clamp  520 . Conveyor  680  may be, but is not limited to being, a trolley assembly, a wheel assembly, a slide assembly, a rack and pinion assembly and/or any device that enables rotor assembly  300  to move as described herein. In an alternative embodiment, conveyor  680  may be, but is not limited to being, one of any combination of a wheel assembly, a slide assembly, a rack and pinion assembly, and/or any other assembly that enables conveyor  260  to function as described herein. 
   Movement of second conveyor  680  and trolley  262  causes rotor assembly  300  to be moved further into bore  340  and causes outer stub clamp  520  to contact a generator gear  700 . Outer stub clamp  520  is then coupled to generator gear  700  to facilitate supporting rotor assembly  300 . More specifically, at this phase of installation, rotor assembly  300  is supported by generator gear  700  and trolley  262 , and conveyor  680  may be uncoupled from outer stub clamp  520  and coupled to inner stub clamp  500 . Outer stub clamp  520  is then uncoupled from both generator gear  700  and first rotor  380 . 
   Rotor assembly  300  is supported by trolley  262  and second conveyor  680  via inner stub clamp  500 . Second conveyor  680  and trolley  262  are then moved to cause rotor assembly  300  to move further into bore  340  and to cause inner stub clamp  500  to contact generator gear  700 . Inner stub clamp  500  is then coupled to generator gear  700  such that rotor assembly  300  is supported by generator gear  700  and trolley  262 . Conveyor  680  is then uncoupled from inner stub clamp  500  and coupled to first rotor  380  via a fourth clamp  720 . Furthermore, a stabilizer  580  is connected to fourth clamp  720  to facilitate preventing swaying of rotor assembly  300 . Inner stub clamp  500  is uncoupled from first rotor  380  and generator gear  700  such that rotor assembly  300  is supported by trolley  262  and conveyor  680 . Conveyor  680  and trolley  262  are then moved causing rotor assembly  300  to be inserted further into bore  340  and such that first rotor  380  contacts generator gear  700 . First rotor  380  is then coupled to generator gear  700 . 
   A pedestal  760  is positioned under second rotor  400  such that rotor assembly  300  is supported by generator gear  700  and pedestal  760 . Skid pan  740  is then removed from between rotor assembly core  360  and stator bore surface  600 , and second shoe  570  is also removed. Next, both trolley  262  and conveyor  680  are uncoupled from rotor assembly  300 , and stabilizers  580  and  581  are removed. Finally, fourth clamp  720  and second clamp  460  are removed. Rotor assembly  300  is now positioned within stator bore  340  and prepared for operation. 
   The above-described methods and system facilitate the installation of a rotor assembly within a generator stator bore. Specifically, the above-described methods and system enable the rotor assembly to be inserted without requiring excessive or awkward repositioning of the rotor assembly. More specifically, repeated manipulation at several different angles is limited by the above-described methods and system. Furthermore, the above-described methods and system facilitate providing a means to insert a rotor assembly without having to apply pressure or weight to the rotor assembly core. As a result, the rotor assembly can be inserted by a means that is both reliable and cost effective. 
     FIGS. 8-12  illustrate subsequent stages of removal of a rotor assembly  300  from a bore  340  of a generator stator  320  using assembly system  100 . For clarity, support assembly  120  is not illustrated in  FIGS. 8-12 . Specifically,  FIG. 8  is a side view of rotor assembly  300  prepared to be removed from stator bore  340 ,  FIG. 9  is a side view of an initial removal of rotor assembly  300 , and  FIG. 10  is a side view of subsequent removal of rotor assembly  300  from stator bore  340  and positioned such that rotor assembly  300  is supported by shoe  540  and trolley  262 .  FIG. 11  is a side view of rotor assembly  300  moved to an entry end of stator bore  340  and  FIG. 12  is a side view of rotor assembly  300  completely removed from generator stator  320 . 
   Prior to removal, trolley  262  is coupled to second rotor  400  via third clamp  590 . Third clamp  590  includes a stabilizer  580  coupled thereto to make contact with lateral support members  174  to facilitate preventing swaying of rotor assembly  300  during removal. Pedestal  760  is removed from second rotor  400  causing rotor assembly  300  to be supported by generator gear  700  and trolley  262  via third clamp  590 . Skid pan  740  is positioned between rotor assembly core  360  and stator bore surface  600  to enable translation of rotor assembly  300  through bore  340 . 
   First rotor  380  is coupled to conveyor  680  via fourth clamp  720 , and a tension member  800  is extended axially from second rotor  400 . First rotor  380  is then uncoupled from generator gear  700  such that rotor assembly  300  is supported by conveyor  680  and trolley  262 . A stabilizer  581  is coupled to fourth clamp  720  and shoe  570  is coupled to first rotor  380 . First rotor  380  is then uncoupled from generator gear  700  such that tension applied to tension member  800  and translation of conveyor  680  and trolley  262  enable rotor assembly  300  to move out of stator bore  340 . Rotor assembly  300  is moved until a distance between generator gear  700  and first rotor  380  is wide enough to enable inner stub clamp  500  to be coupled to first rotor  380 . 
   Inner stub clamp  500  is coupled to first rotor  380  and then to generator gear  700  such that rotor assembly  300  is supported by generator gear  700  and trolley  262 . Conveyor  680  is uncoupled from fourth clamp  720  and coupled to inner stub clamp  500 . Inner stub clamp  500  is removed from generator gear  700 , and stabilizer  580  is also removed, enabling rotor assembly  300  to move due to tension applied to tension member  800  and due to translation of conveyor  680  and trolley  262 . Rotor assembly  300  is moved until a distance between generator gear  700  and inner stub clamp  500  is wide enough to enable outer stub clamp  520  to be coupled to inner stub clamp  500 . 
   Outer stub clamp  520  is coupled to inner stub clamp  500  and then to generator gear  700  such that rotor assembly  300  is supported by generator gear  700  and trolley  262 . Conveyor  680  is uncoupled from inner stub clamp  500  and coupled to outer stub clamp  520 . Outer stub clamp  520  is removed from generator gear  700  such that rotor assembly  300  is moved by tension applied to tension member  800  and by translation of conveyor  680  and trolley  262 . 
   Rotor assembly  300  is moved until shoe  540  contacts skid pan  740 . Conveyor  680  is removed from outer stub clamp  520 . During subsequent removal of rotor assembly  300 , shoe  540  slides along skid pan  740  such that rotor assembly  300  is supported by trolley  262  and shoe  540 . When rotor assembly  300  reaches an entry end  820  of stator bore  340 , support member  610  is positioned beneath second rotor  400  such that rotor assembly  300  is supported by support member  610  and by shoe  540 . 
   Trolley  262  is uncoupled from second rotor  400  and repositioned from a second position  628 , aligned with second rotor  400 , to a first position  624 , aligned with first rotor  380 . Trolley  262  is then coupled to first rotor  380  via clamp  420 , and trolley  264  is coupled to second rotor  400  via clamp  460 . Support member  610  is removed such that rotor assembly  300  is supported by trolleys  262  and  264 . Tension applied to tension member  800  and translation of trolleys  262  and  264  facilitates removing rotor assembly  300  from generator stator  320 . 
   The above-described methods and system facilitate the removal of a rotor assembly from a generator stator bore. Specifically, the above-described methods and system enable the rotor assembly to be removed without requiring excessive or awkward repositioning of the rotor assembly. More specifically, repeated manipulation at several different angles is limited by the above-described methods and system. Furthermore, the above-described methods and system facilitate providing a means to remove a rotor assembly without having to apply pressure or weight to the rotor assembly core. As a result, the rotor assembly can be removed by a means that is both reliable and cost effective. 
   As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. 
   Although the methods and systems described herein are described in the context of inserting and removing a rotor assembly for a generator, it is understood that the methods and systems described herein are not limited to field assemblies or generators. Likewise, the system components illustrated are not limited to the specific embodiments described herein, but rather, components of the system can be utilized independently and separately from other 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.