Abstract:
A manipulator assembly for supporting and manipulating a nozzle segment, for example of a gas turbine or a steam turbine. The assembly includes a vertical support member and a horizontal support member. The vertical support member is mounted for selective vertical displacement relative to a base and the horizontal support member is operatively coupled at a proximal end thereof to the vertical support member so as to be vertically displaced therewith and so as to be pivotable about a vertical axis of the vertical support member. A nozzle segment fixture is operatively coupled to a distal end of the horizontal support member for selectively supporting and manipulating a nozzle segment.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to turbine repair engineering and, more particularly, to a manipulator for manipulating a nozzle assembly of a turbine during brazing and welding.  
         [0002]     Nozzles, which typically weigh up to 200 pounds, cannot be safely manipulated by hand on a work bench. Furthermore, attempts to move a nozzle assembly can result in damage to the parts and injury to the operator.  
       BRIEF DESCRIPTION OF THE INVENTION  
       [0003]     A manipulator is provided in accordance with an example embodiment of the invention to support a nozzle segment, for example from a gas turbine or from a steam turbine, and allow it to be moved vertically, horizontally and rotated for proper positioning, and then held motionless during welding or brazing.  
         [0004]     Thus, the invention may be embodied in a manipulator assembly for supporting and manipulating a nozzle segment, comprising: a manipulator including a vertical support member and a horizontal support member, the vertical support member being mounted for selective vertical displacement relative to a base, the horizontal support member being operatively coupled at a proximal end thereof to said vertical support member so as to be vertically displaced therewith and so as to be pivotable about a vertical axis of said vertical support member; and a nozzle segment fixture, said fixture being operatively coupled to a distal end of said horizontal support member and having coupling components respectively complimentary to first and second radial ends of a nozzle segment to selectively engage the nozzle segment.  
         [0005]     The invention may also be embodied in a method of manipulating a nozzle segment during brazing, welding and/or inspection, comprising: providing a manipulator including a vertical support member, a horizontal support member, and a nozzle segment fixture operatively coupled to a distal end of said horizontal support member, the vertical support member being mounted for selective vertical displacement relative to a base, the horizontal support member being operatively coupled at a proximal end thereof to said vertical support member so as to be vertically displaced therewith and so as to be pivotable about a vertical axis of said vertical support member; coupling a nozzle segment at each longitudinal end thereof to said nozzle segment fixture; and selectively at least one (a) a vertically displacing said vertical support member and (b) pivoting said horizontal support member about a vertical axis of said vertical support member so as to selectively, vertically and horizontally displace said nozzle segment fixture with respect to a work surface. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     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:  
         [0007]      FIG. 1  is a schematic top plan view of a nozzle manipulator assembly supporting a nozzle segment over a bench according to an example embodiment of the invention;  
         [0008]      FIG. 2  is a side elevational view of the manipulator assembly of  FIG. 1 ;  
         [0009]      FIG. 3  is a front view of a manipulator embodying the invention with the nozzle segment supporting fixture omitted for clarity;  
         [0010]      FIG. 4  is a view taken along line  4 - 4  of  FIG. 3 ;  
         [0011]      FIG. 5  is a plan view of a nozzle segment supporting fixture according to an example embodiment of the invention with nozzle specific tooling omitted for clarity;  
         [0012]      FIG. 6  is a rear elevational view of the fixture of  FIG. 5 ;  
         [0013]      FIG. 7  is a perspective view, from the rear and above, of the fixture of  FIG. 5 , with tooling omitted for clarity;  
         [0014]      FIG. 8  is a plan view of another nozzle segment supporting fixture including examples of nozzle specific tooling;  
         [0015]      FIG. 9  is a rear elevational view of the fixture and tooling of  FIG. 8 ;  
         [0016]      FIG. 10  is a side elevational view of the fixture and tooling of  FIG. 9 ; and  
         [0017]      FIG. 11  is a view taken along line  11 - 11  of  FIG. 10 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]     A manipulator assembly  10  for supporting and moving a nozzle segment during welding, brazing or other inspection or repair is schematically illustrated in  FIGS. 1 and 2 . As illustrated therein, in an example embodiment of the invention, the manipulator assembly includes a manipulator  12  and a nozzle segment supporting fixture  14 . The manipulator is disposed to allow a nozzle segment  16  supported in the nozzle fixture  14  to be moved vertically as shown by arrow V and horizontally over, e.g., a bench  18 . In the illustrated example embodiment, horizontal movement is accomplished by providing a manipulator  12  including a vertical segment  20  and a horizontal segment  22 , the horizontal segment  22  being pivotably mounted (B) with respect to the vertical segment  20 . In this embodiment, a nozzle segment fixture mount  24  is in turn pivotally mounted (D) to the distal end  26  of the horizontal segment  22 . Thus, simultaneous pivoting movement about axis A and axis C, as shown by arrows B and D, results in movement of the nozzle segment fixture  14  in a horizontal plane, while maintaining the orientation of the nozzle segment  16  with respect to the operator X.  
         [0019]     The vertical segment  20  of the manipulator  12  in the illustrated embodiment is comprised of a pillar or post and base assembly  28  and a support tube  30  that is electively displaced upwardly and downwardly along the post according to actuation of the hydraulic cylinder  32 .  
         [0020]     As mentioned above, the horizontal segment  22  is mounted to pivot about axis A of the vertical segment  20 . To this end, in the illustrated example embodiment, the horizontal segment  22  includes a generally cylindrical receptacle  34  that is rotatably disposed on a sleeve  36  seated on the support tube  30  so that as the support tube  30  is raised and lowered (V) by the hydraulic cylinder  32 , the proximal end  38  of the horizontal segment  22  is likewise raised and lowered. As mentioned above, the fixture mount  24  is mounted to pivot about axis C at the distal end of the horizontal segment. To this end, in the illustrated example embodiment, the distal end  26  of the horizontal segment  22  includes a vertical oriented sleeve  40  to which the mounting assembly of the nozzle segment fixture is pivotally mounted as with the cylindrical bands  42 , 44  schematically depicted in  FIGS. 2 and 4 .  
         [0021]     In the illustrated example embodiment, movement of the nozzle segment fixture  14  and mount  12  about pivot C and movement of horizontal segment  22  about pivot A is effected manually. Further, in an example embodiment the rotational axes are supported on taper roller bearings with load controls to regulate ease of manual movement. The rotational axes also advantageously have locks (not shown in detail) in order to immobilize each axis independently. It is to be understood, however, that pivoting movement of the horizontal segment  22  and/or of the fixture mount  24  can be automated without departing from this invention. Furthermore, although the horizontal segment  22  is schematically depicted as being of fixed length, those skilled in the art will appreciate that the horizontal arm can be formed from e.g., telescoping tubes to selectively provide for elongation and contraction of the horizontal arm along its axis. Extension of the horizontal arm can be automated by the inclusion of a suitable hydraulic cylinder or other drive mechanism(s) known in the art.  
         [0022]     As noted above, the manipulator  12  and fixture  14  are adapted to support and manipulate a nozzle segment  16  weighing, for example, in excess of two hundred pounds. Therefore, in the illustrated example embodiment, the fixture  14  is configured as a rigid support to resist bending loads due to the cantilever support of the nozzle segment with respect to the horizontal segment  22 . Furthermore, in an example embodiment of the invention, more than one nozzle segment fixture  14 , 114  may be provided to be selectively mounted to the manipulator  12  to accommodate nozzle segments of differing sizes/lengths. The nozzle segment fixtures  14 , 114  in the illustrated embodiments are generally U-shaped having a base  50 , 150  mounted to the fixture mount  24  and first and second arms  52 , 54 ; 152 , 154  extending horizontally therefrom for being secured to respective radial ends of the nozzle segment.  
         [0023]     To secure the nozzles respectively to the nozzle fixture, interchangeable tooling or ears  56 , 58 ; 156 , 158  that are nozzle specific are provided to be selectively secured to each arm of the fixture. Thus the interchangeable tooling  56 , 58 ; 156 , 158  is specific to the nozzle segment configuration, and the fixtures  14 , 114  are respectively configured for accepting a variety of nozzles of generally similar size/length. The interchangeable tooling is mounted to the fixture arms so that the nozzle segment, once secured to the tooling, can be selectively rotated (N) with respect to the fixture arms. As noted above, with respect to the manipulator structure, advantageously a bearing structure for rotating the nozzle is designed so as to preclude free rotation of the supported part, so that manual intervention is required to effect rotation of the nozzle segment. The nozzle segment may then be locked in a particular orientation so that unintended rotation is precluded. Once again, selective, powered movement, in this case rotation of the nozzle segment, can be accommodated by providing a suitable drive mechanism for selectively rotating the nozzle specific tooling with respect to the fixture arms.  
         [0024]     In the illustrated example embodiment, the work bench  18  over which the nozzle segment  16  is suspended by the fixture  14 , 114  is a downdraft table having an opening or cutout  19 , which will generally have a grate (not shown) therein, through which air is sucked downwards to remove e.g. dust particles and solvent fumes during braze application. The invention is not limited to the inclusion of a work bench, or the particulars thereof.  
         [0025]     To provide yet a further degree of freedom, the fixture mount  24  may be rotatably disposed with respect to horizontal so as to provide for a selective rotation (F) of the fixture  14 , 114  about an axis (E) perpendicular to pivot axis C. This allows the nozzle segment to be selectively inclined at an angle to horizontal if deemed necessary or desirable to facilitate welding, brazing or inspection. Rotation F about horizontal axis E also selectively facilitates attachment of the nozzle to the fixture. Once again, manual rotation is proposed, with a locking mechanism to selectively preclude manual rotation, but powered rotation is an alternative.  
         [0026]     In one example embodiment of the invention a foot pedal is used to control the hydraulic cylinder  32  for lifting and lowering the horizontal segment  22  of the manipulator  12 . In another example, a two button controller is used, e.g. with an up button and a down button that are selectively depressed for corresponding control of the hydraulic cylinder  32 .  
         [0027]     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.