Abstract:
An assembly for lifting and supporting a journal body with respect to a stationary body including: a support bracket for being secured to said stationary body; an elongated support member to engage and support a bottom facing surface of the journal body; first and second support studs operatively coupled at a distal end thereof to a respective longitudinal end of said elongated support member and adjustably coupled at the proximal end thereof via a respective lift assembly to said support bracket, wherein each said lift assembly comprises a hydraulic cylinder operatively coupled to said proximal end of said support stud so as to selectively determine a position of said support stud with respect to support bracket thereby to selectively adjust and determine a position of said journal body with respect to said stationary body.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to an assembly and method for lifting and supporting the generator field in the stator frame to allow the insertion or removal of the hydrogen seal casing, inner oil deflector, field body shoe, skid pan, and other generator or field hardware.  
           [0002]    With reference to FIGS. 1 and 2, conventionally, the generator field  10  is positioned and moved using support studs  12  installed through a support assembly with spherical nuts  14 , in order to raise and lower the generator field. More specifically, a support bracket, sometimes as referred to as an eyebrow  16 , is bolted to the stator frame  18  with bolts  20 . The bracket has spaced bores  22  and spherical receptacles  24  for receiving the support studs  12  and spherical nuts  14 , respectively. The distal end  26  of each support stud is secured to a respective clevis  28  coupled to a respective longitudinal end of a cable  30  that extends below the generator field  10 . As illustrated, a protective journal shim  32  is provided between the cable  30  and the generator field  10 . The spherical nuts  14  are threaded to the support studs  12  for selectively adjusting their position relative to the eyebrow  16  to in turn adjust the position of the cable and the generator field supported thereby. Thus, in the conventional structure, by rotating the spherical nuts  14 , the position of the generator field  10  can be adjusted up and down to position and move the generator field as required.  
           [0003]    With this conventional design, there is a significant amount of weight on each of the spherical nuts. This results in a large friction force and makes it difficult to turn the nuts to adjust the stud position. Indeed, large impact wrenches have to be utilized along with torque multipliers to turn the nuts. As a result, in most cases, the station crane must used to elevate the field, removing weight from the studs/nuts so that the required length adjustment can be made. Thus, the current system is labor intensive and difficult to perform. It would be desirable to eliminate crane usage and make the process faster, easier and less labor intensive.  
         BRIEF DESCRIPTION OF THE INVENTION  
         [0004]    The present invention provides an assembly and method for accurate and controllable positioning of the generator field while it is still in the stator frame. The assembly of the invention allows on-site personnel to make elevation adjustments in a much quicker, easier and safer way then the above-described conventional system. Indeed, the assembly and method of the invention eliminates crane usage at this stage of generator assembly or disassembly; shortens the duration for generator disassembly and assembly while making the adjustment safer, easier and quicker; and makes the generator field movement easier, which allows more accurate positioning.  
           [0005]    The invention achieves these objectives by modifying the conventional design to provide for lifting via hydraulic cylinders. Thus, the invention is embodied in an assembly for lifting and supporting a journal body with respect to a stationary body comprising: a support bracket for being secured to said stationary body; an elongated support member to engage and support a bottom facing surface of the journal body; at least one hydraulic lift assembly mounted to said support bracket, each said lift assembly including a hydraulic cylinder; a support stud operatively coupled, adjacent a proximal end thereof, to each said hydraulic lift assembly; and each said support stud being operatively coupled, adjacent a distal end thereof, to said elongated support member; whereby actuation of said hydraulic cylinder selectively lifts said support stud and said support member coupled thereto, thereby to selectively lift and determine a position of said journal body with respect to said stationary body.  
           [0006]    The invention may also be embodied in a method for lifting and supporting a journal body with respect to a stationary body comprising: securing a support bracket to said stationary body; disposing an elongated support member to engage a bottom facing surface of the journal body; mounting at least one hydraulic lift assembly to said support bracket, each said lift assembly including a hydraulic cylinder; operatively coupling a support stud, adjacent a proximal end thereof, to each said hydraulic lift assembly; operatively coupling each said support stud, adjacent a distal end thereof to said elongated support member; and selectively actuating said at least one hydraulic lift assembly to selectively raise and lower said support stud to selectively adjust and determine a position of said journal body with respect to said stationary body.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    These and other objects and advantages of this invention, will be more completely understood and appreciated by careful study of the following more detailed description of the presently preferred exemplary embodiments of the invention taken in conjunction with the accompanying drawings, in which:  
         [0008]    [0008]FIG. 1 is an elevational view of a conventional lift and support assembly for a generator field;  
         [0009]    [0009]FIG. 2 is a side view, partly broken away for clarity, of the assembly of FIG. 1;  
         [0010]    [0010]FIG. 3 is a schematic cross-sectional view of a lift and support assembly provided as an embodiment of the invention; and  
         [0011]    [0011]FIG. 4 is an exploded perspective view of a portion of the lift assembly of the FIG. 3 embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]    The assembly and process of the invention can be applied to any system where a journal body or core needs to be lifted and positioned or supported with respect to a stationary body, to allow the assembly and removal of associated components between the core and the stationary body. By way of non-limiting example, the assembly and process of the invention are applied to generator assemblies in which the generator field needs to be positioned with respect to the stator frame to allow for the assembly and removal of the hydrogen seal casing, inner oil deflector, seal body shoe, skid pan and/or other equipment. The assembly of the invention allows the generator field to be raised up or set down within the stator frame quickly and easily for these and any other purpose. The invention may be readily applied to any generator that presently has a rotor sling  30  and support assembly (eyebrow) rig  16  of the type generally described above with reference to FIGS. 1 and 2.  
         [0013]    In an exemplary embodiment described hereinbelow, the lift assembly  100  of the invention is similar in some respects to the conventional lift assembly. For that reason generally corresponding parts are identified with corresponding reference numerals incremented by 100.  
         [0014]    In an exemplary embodiment of the proposed assembly two support studs  112  are provided as in the conventional assembly, each coupled to an associated hydraulic lifting assembly. However, for ease of description, only a single hydraulic lifting assembly  100  is illustrated and described hereinbelow. Moreover, it is to be understood that in some adaptations, the advantages of the invention may be realized with a single hydraulic lifting assembly suitably coupled to a sling assembly.  
         [0015]    As mentioned above, in an embodiment of the invention, the displacement of the support studs  112  to lift the journal body (not shown in FIGS. 3-4), for example, a generator field, with respect to a stationary body (not shown in FIG. 3-4), for example a stator frame, is facilitated with hydraulic cylinders  134  (only one of which is shown in FIG. 3), one associated with each support stud  112 . Collars, washers and nuts are secured to the hydraulic cylinder  134  and support stud  112  as set forth in greater detail below. The hydraulic cylinders can then raise and lower the respective support stud, adjusting the generator field or other journal body up and down.  
         [0016]    Referring to FIG. 3, one of the two support studs  112  provided to support and position a core or journal body is schematically illustrated. The stud has a proximal end  138  operatively coupled to a coupling and lift assembly  114  and a distal end  126 , which is operatively coupled to the sling engaged with the core body. Reference will be made hereinafter, by way of example and not limitation, to the lifting and supporting of a generator field.  
         [0017]    In an exemplary embodiment, the sling is comprised of a cable  30  having a support eye  34  defined at each longitudinal end, as shown in FIGS. 1 and 2 which is engaged with and supported by a respective clevis  128 . Thus, in this exemplary embodiment, the support stud  112  is operatively coupled at distal end  126  thereof to the clevis  128  that in turn pivotally supports the cable  30  defining the journal body sling.  
         [0018]    As in the conventional assembly, a support bracket or eyebrow  116  is secured, e.g., with bolts  120  to the stationary body (stator frame). As such, the support bracket  116  includes a vertical flange  140  which is secured with respect to the stator frame (not shown) by bolts  120  and has horizontal flange  142  having bores  122  for receiving the first and second support studs  112 . In an exemplary embodiment, the support bracket  116  is modified from the conventional configuration to space the support stud hole  122  away from the stator frame and the threaded portion  136  on the proximal end  138  of the support stud  112  is longer than in the conventional system, to accommodate a hydraulic cylinder  134 . As in the conventional structure, supports (not shown in FIG. 3) similar to the supports  44  that extend between the vertical wall  40  and the horizontal flange  42  of the support bracket  16 , extend between the vertical flange  140  and the horizontal flange  142  of the support bracket  116  to brace and reinforce the assembly.  
         [0019]    The coupling and lift assembly  114  is advantageously supported on the support bracket  116  in a manner that allows pivotal displacement of stud  112  with respect to the support bracket  116  as required to accommodate the orientation of the cable and cleavis assemblies, which may not be perfectly vertical. To this end, a pivot support is placed between the distal end of the hydraulic cylinder  134  and the horizontal flange  142  of the support bracket.  
         [0020]    In the illustrated embodiment the pivot assembly  156  is comprised of a pivot shoe  144  having a flat surface  146  engaging the horizontal flange  142  of the support bracket and a part spherical surface  148 . The pivot assembly further includes a pivot leg  150  having a generally flat surface  152  for engaging the lift assembly components disposed thereabove and a part spherical surface  154  for engaging the part spherical surface  148  of the pivot shoe. In the illustrated embodiment, the part spherical surface of the pivot shoe is concave and the part spherical surface of the pivot leg is convex. It is to be understood that the pivot assembly of the lift assembly of the invention is not limited to the number and configuration of pivot parts illustrated and described above.  
         [0021]    In the illustrated embodiment, the hydraulic cylinder  134  is seated directly on the pivot assembly  156 . It is to be understood, however, that additional spacer structures, e.g., washers, may be interposed between the pivot assembly  156  and the hydraulic cylinder  134  as deemed necessary or desirable to vertically dispose the hydraulic cylinder  134  to minimize interference between the coupling and lift assembly  114  and the support bracket  116  and associated coupling structures  120 .  
         [0022]    The hydraulic cylinder  134  is preferably a hollow plunger cylinder so that the support stud  112  may be disposed to extend through the hydraulic cylinder. In an exemplary embodiment, the cylinder capacity is 60 tons and has e.g., a 6-inch stroke. A suitable such cylinder is available from Enerpac, as Model Number RCH-606. By way of example, that cylinder has an outside diameter of about 6.25 inches, a center hole diameter of about 2.12 inches, and a height of about 18.75 inches. When such a cylinder is utilized in the assembly of the invention, the stud  112  advantageously has an outer diameter of about 2 inches. Further, in an exemplary embodiment, the support stud has a length on the order of 48 inches, the distal portion  126  being threaded, as at  158 , along approximately 4 inches of its length and the proximal end  138  of the stud being threaded, as at  160 , along approximately 28 inches of its length.  
         [0023]    In an exemplary embodiment, the pivot leg  150  has an outer diameter of about 6 inches and a height of about 4 inches and the pivot shoe  144  has an outer diameter of about 7 inches. To accommodate relative pivoting movement of the support stud, in an exemplary embodiment, the inner diameters of the pivot shoe and the pivot leg are about 3 inches.  
         [0024]    In the illustrated embodiment, the coupling and lift assembly  114  for the support stud  112  includes a stop ring  162  which is threadedly engaged with the hydraulic cylinder  134 , which is itself threaded as at  164  on the exterior surface of its proximal end, and then locked with respect thereto by set screws  166  threaded through radial bores  168  defined at spaced locations about the circumference of the stop ring  162 . A stop collar  170  is then threadably engaged to a threaded outer surface  172  of the stop ring  162 . Radial turning holes  174  are defined at spaced locations about the circumference of the stop collar  170  to facilitate proper positioning of the stop collar, as described in greater detail below. A stop washer  176  is seated atop the stop collar  170  and has an outer diameter generally corresponding to that of the stop collar. The stop collar may be adjusted with respect to the stop ring/hydraulic cylinder to determine the position of the stop washer  176  on or above the piston  135  of the hydraulic cylinder. The support stud  112  is threaded through the lift assembly  114  and a hex nut  178  is threaded to the support stud  112 , operatively coupling support stud to the coupling and lift assembly  114 . As will be appreciated, when the hydraulic cylinder  134  is actuated to extend piston  135 , stop washer  176  and nut  178  seated thereon are lifted by the piston  135 , thereby lifting the associated support stud  112  and sling coupled thereto. When the hydraulic cylinder is (de) actuated to withdraw piston  135 , the stop washer will be selectively lowered until it engages the stop collar  170 , so that the stop collar  170  defines the end of the downward stroke of the support stud  112 .  
         [0025]    As can be seen in FIG. 3, the stop collar  170  has a length that is about 3 times that of the stop ring  162  to determine with greater flexibility the supported position of the support stud. In the illustrated embodiment, the stop ring  162  has a length of about 2 inches and an outer diameter of about 8.375 inches, whereas the stop collar  170  has a length on the order of about  6  inches. The inner diameter of the stop ring  162  is sized and threaded to mate with the threads on the outer surface of the hydraulic cylinder  134 .  
         [0026]    The hydraulic lifting assembly  100  of the invention is set up as follows. The stop ring  162  is threaded onto the hydraulic cylinder  134  and the set screws  166  are installed to lock the stop ring  162  with respect to the cylinder  134 . As will be understood, the setscrews help prevent rotation of the stop ring with respect to the cylinder. The stop collar  170  is then threaded onto the stop ring. The support bracket or eyebrow  116  is installed on the generator (stator) frame (not shown in FIGS. 3 and 4), e.g. with bolts  120 . A hydraulic cylinder  134 , pivot leg  150  and pivot shoe  144  for each stud is then seated onto the support bracket  116 , concentrically aligned to a respective stud hole  122 . If required, additional washers or spacers may be added between the base of the hydraulic cylinder  134  and the pivot leg  150  in order to prevent interference between the support bracket  116  and/or bolts  120  and the stop collar  170 , as mentioned above.  
         [0027]    Next, the large stop washer  176  is placed on top of the stop collar  170 . The support stud  112  is threaded through the stop washer  176 , hydraulic cylinder  134 , pivot leg  150 , pivot shoe  144 , and support bracket  116 , and. The hex nut  178 , threadably engaged with the stud  112 , prevents the stud from sliding through the hydraulic cylinder. The clevises  128  are then attached to the distal end  126  of the studs. Using the sling and clevis hardware (not shown in FIGS. 3 and 4), the sling is disposed around the generator field and secured at each longitudinal end to the respective clevis. The hex nuts are then adjusted to remove any excess slack in the sling. Hydraulic lines (not shown) are then attached to the cylinders  134  at one end and operatively coupled at the opposite end to a suitable electric/hydraulic pumping system (not shown). T-fitting or a suitable hydraulic manifold may b provided to couple the hydraulic lines to the pumping system. The hydraulic cylinders are both actuated at the same time through the supply lines whereby the generator field may be lifted and lowered via the hydraulic cylinders.  
         [0028]    While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.