Abstract:
The present disclosure relates to the technical field of tools for generators or machines and to methods for assembling parts to electrical generators or machines by means of tools. Objects of the invention are to ensure an easy, safe, and time-consuming assembly of an inner enclosure to a generator or a machine. The objects are solved by a tool for the assembly of an inner enclosure of a generator or a machine, whereby the tool comprises a first part and a second part, the first part comprises a plate which comprises at one side a half-ring, the second part comprises a half-ring corresponding to the half-ring of the first part to be assembled to a full-ring to encompass the shaft of the generator or the machine and be fixed to the inner enclosure in maintenance operation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to European application 14160295.3 filed Mar. 17, 2014, the contents of which are hereby incorporated in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present disclosure relates to the technical field of tools for generators or machines and to methods for assembling parts to electrical generators or machines by means of tools. 
         [0003]    The electric generator is in particular a rotating electric generator such as a synchronous generator to be connected to a gas or steam turbine (turbogenerator) or a synchronous generator to be connected to a hydro turbine (hydro generator) or an asynchronous generator or a synchronous or asynchronous electric motor, or also other types of electric machines. The invention refers to a generator or machine and especially to a certain part surrounding the end of the outer area of the shaft of the generator or machine, the inner enclosure. 
       BACKGROUND 
       [0004]    Assembling an electric generator or machine for high or medium power is based on handling heavy weight parts to be connected in a precise and safe manner. Parts to be assembled are big in size and have a weight making it necessary to use cranes to move the several parts. Heavy weight cranes moving heavy parts in an assembly area are nevertheless a source of danger for persons and material. A certain part to be assembled is the so called inner enclosure which is a part surrounding the outer area at the end of the shaft of the generator or machine. When performing the assembly of the inner enclosure especially the rotor fan blade of the generator is endangered to damage. One prior art uses six prefabricated parts to be assembled to the single inner enclosure and accordingly six assembly processes to add all these parts. Next to the danger handling these parts the many fabrication steps are time consuming and expensive. 
         [0005]    An object of the invention is to avoid the aforesaid problems in assembly procedures to assure a safe and precise assembly of parts for generators or machines. 
       SUMMARY 
       [0006]    Provided is a tool for the assembly of a generator or machine according to claim  1 . Further, a use of a tool and a method for assembling a generator or machine is provided according to claims  6  and  7 , respectively. 
         [0007]    In one example the tool is provided with holes through the plate fitting to corresponding holes at the inner enclosure for connecting the plate to the inner enclosure. By means of pins or bolts a secure connection between the plate and the inner enclosure is established. The inner enclosure together with the tool comprising the plate can then be assembled to the generator or machine. 
         [0008]    In another example ribs are connected to the plate of the first part and/or to the half-ring of the second part projecting perpendicular from the corresponding first part or second part. The ribs mainly have a rectangular cross-section. The main function of the ribs is to stabilize the plate and the first part of the tool and to stiffen it. 
         [0009]    In another example of the invention the plate of the first part has at least one cut-out. Advantage of this measure is that a reduced weight is achieved. Several cut-outs can be designed along the area of the plate with different shapes and sizes. Here, three round cut-outs are designed as an example. 
         [0010]    In a further example of the invention the first part and the second part of the tool each have a connection plate at their ends to be joint and with which the first part and the second part are to be connected by screws to create a full-ring. The connection plates have bores, e.g. each connection plate has two bores through which the screws can project and be fixed by a screw nut each. By this measure the first part and the second part have a secure and detachable connection. 
         [0011]    Furthermore, a method to assemble a generator or a machine with a tool according to the invention is provided. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Further characteristics and advantages will be more apparent from the description of a preferred but non-exclusive embodiment of the tool, illustrated by way of non-limiting example in the accompanying drawings, in which: 
           [0013]      FIG. 1  is a schematic perspective view of a tool according to an example of the invention comprising a first part below having a plate with a first half-ring at the above side of the plate and a second part above having a second half-ring, the plate having three cut- outs, and the first part and the second part being connected; 
           [0014]      FIG. 2  is a draft of a schematic front view showing the tool connected to a first half of an inner enclosure to be assembled to a generator or machine; 
           [0015]      FIG. 3  is a draft of a schematic front view similar to  FIG. 2 , the inner enclosure assembled to the generator or machine, and showing the tool moved to the downside; 
           [0016]      FIGS. 4-10  show perspective schematic views of a generator or machine in subsequent phases of the assembly procedure to assemble the inner enclosure to the generator or machine by means of the tool. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    With reference to the figures like reference numerals designate identical or corresponding parts throughout the several views. 
         [0018]      FIG. 1  is a schematic perspective view of a tool  1  according to an example of the invention. Shown is a plate  2  comprised by a first part  10  of the tool  1  in this view below. The plate  2  of the first part  10  is cut at its above side in shape of a half-ring which is opened in the direction above in this perspective. At the edge of the first part  10  a curved face projects along the edge of the cut-out. The face has a certain width perpendicular to the plate  2  and has the shape of a half-ring, the face is denominated as first half-ring  11  in the following. In the example of  FIG. 1  the plate  2  has three cut-outs  25  projecting completely through the plate  2 . Ribs  55  are connected to the plate  2  starting from the first half-ring  11  and projecting with an angle to each other along the plate  2 . A main function of the ribs  55  is to provide a stiffness to the plate  2 . Further, plate  2  has several holes  26 , in this example eight holes  26  distributed along the lower side of the plate  2  in this perspective, distant to the half-ring cut-out  25  and the first half-ring  11 . The holes  26  serve as a means for establishing a connection to an inner enclosure  5 ,  6  as will be described below. The tool  1  comprises a second part  20  in the view above essentially comprising a second curved face formed as half- ring, in the following denominated as second half-ring  13 . Regarding size and flection the second half-ring  13  is similar to the first half-ring  11 . The first half-ring  11  and the second half-ring  13  each comprise connection plates  30  at each end, as shown in  FIG. 1 . The connection plates  30  are formed perpendicular to the end of the half-rings  11 ,  13  and have the same width as these. Connection plates  30  have plane faces to be joint in a way that the half-rings  11 ,  13  being assembled to form a full- ring  22 . To the end of fixing together the half-rings  11 ,  13  in a force closure, bores are provided in the connection plates  30  for including screws  33  or bolts through the connection plates  30  of the half-rings  11 ,  13 . Screw nuts are connected with the screws to establish a removable connection between the first half-ring  11  and the second half-ring  13  of the tool  1 . In  FIG. 1  the second part  20  comprises two ribs  55  projecting from the two ends of the first half-ring  11  along a section of the second part  20 . The first part  10  and the second part  20  create a full ring in  FIG. 1 , which serves for enclosing a shaft  41  of a generator  40  or machine  40 . 
         [0019]      FIG. 2  shows a draft of a schematic front view of the tool  1  connected to a part of an inner enclosure  5 ,  6 . The inner enclosure  5 ,  6  is a part of the generator  40  or machine  40  at one end to essentially close the running parts of the generator  40  or machine  40  against the environment. The inner enclosure  5 ,  6  has a circular shape, in  FIG. 2  one half of the inner enclosure  5  is shown. The second half of the inner enclosure  6  is to be assembled as will be described below. Here, the tool  1  is put onto the shaft  41  and the first part  10  and the second part  20  of the tool  1  are assembled to a full-ring similar to  FIG. 1  and described above. 
         [0020]      FIG. 3  shows a draft of a schematic front view similar to  FIG. 2 . Here, the second half of the inner enclosure  6  is assembled to the full inner enclosure  5 ,  6 . In this front view the generator  40  or machine  40  is put onto the support  43 , the inner enclosure  5 ,  6  fills most of the open area in the axial direction of the generator  40  or machine  40  and thus in the direction of the shaft  41 . It is visible in  FIG. 3  that the tool  1  is turned down, the first part  10  of the tool  1  is directed to the bottom. This is due to the assembling process in which the tool  1  with the first half of the inner enclosure  5  is turned to the other side of the shaft  41  to enable the assembly of the second half of the inner enclosure  6  as is described below. 
         [0021]      FIG. 4  shows a perspective schematic view of a generator  40  or machine  40  in a first phase of the assembly procedure to assemble the inner enclosure  5 ,  6  to the generator  40  or machine  40  by means of the tool  1 . The generator  40  or machine  40  rests on a support  43 , commonly fixed to the ground of a generator hall. In this first method step the first part  10  of the tool  1  is releasably connected to the first half of the inner enclosure  5  by means of pins or bolts reaching through the holes  26  in the plate  2  of the first part of the tool  10 . Also shown in  FIG. 4  is the second half of the inner enclosure  6  below the first part of the tool  10  connected to the first half of the inner enclosure  5 . 
         [0022]      FIG. 5  shows a second step of manufacturing of the inner enclosure  5 ,  6  to the generator  40  or machine  40 . Here, the first part  10  of the tool  1  releasably connected to the first half of the inner enclosure  5  is assembled to the shaft  41  of the generator  40  or machine  40 . The first part  10  and the second part  20  of the tool are bolt together to encompass the shaft  41 . The half-ring  11  of the first part  10  of the tool  1  abuts the shaft  41 , there is a gap between the first half  5  of the inner enclosure  5 ,  6  and the shaft  41 . In this view the plate  2  and the first half  5  of the inner enclosure  5 ,  6  are directed upwards. The two parts, the tool  1  and the first half  5  of the inner enclosure  5 ,  6  are typically mounted to the generator  40  or machine  40  by a crane. 
         [0023]      FIG. 6  shows a third step of the method to assemble the inner enclosure  5 ,  6  to the generator  40  or machine  40 . Hereby, the first half  5  of the inner enclosure  5 ,  6  as well as the connected tool  1  are turned by around 180° a half turn around the shaft  41  by turning the plate  2 . This means, the plate  2  and the first half  5  of the inner enclosure  5 ,  6  are directed to the bottom now. The upper part of the housing of the generator  40  or machine  40  is open in this position in an axial direction, the lower part of the housing is closed by the first half  5  of the inner enclosure  5 ,  6 . 
         [0024]      FIG. 7  shows a fourth step of the fabrication method by means of the tool  1 . In this step a second half  6  of the inner enclosure  5 ,  6  is carried to the generator  40  or machine  40  according to  FIG. 6 . This is usually done by a crane because of the high weight of the parts involved in medium or high power generators  40  or machines  40 . The second half  6  of the inner enclosure  5 ,  6  is attached flush with the first half  5 , so the two parts constitute a full circle or full-ring  22 , which is the complete inner enclosure  5 ,  6 . It is to be understood that in an example of the invention the inner enclosure  5 ,  6  is prefabricated out of the first half  5  and the second half  6 . The fabrication step is shown in  FIG. 8 , at which the two halves  5 ,  6  are connected to each other in a common way. At this step the inner enclosure  5 ,  6  is completely assembled with the generator  40  or machine  40 . The inner enclosure  5 ,  6  is assembled supported by the tool  1  as described. The tool  1  arranges for a secure introduction, a smooth adjustment of the two halves  5 ,  6  of the inner enclosure  5 ,  6  and an improved manufacturing process. In this assembled condition the clearance between heavy fan blades of the rotor of the generator  40  and the inner enclosure  5  is about 2-3 mm. 
         [0025]      FIG. 9  shows a sixth step of the manufacturing method using the tool  1 . The tool  1  is turned by an angle of around 45°, so the plate  2  is directed to a side of the generator  40  or machine  40 . The tool  1  is divided into its first part  10  and second part  20  by loosening the screws  33  and removing the parts  10 ,  20 . 
         [0000]    Modifications and variants in addition to those already stated are possible. 
         [0026]    The tool and the method conceived in this manner are susceptible to numerous modifications and variants, all falling within the scope of the inventive concept; moreover all details can be replaced by technically equivalent elements.