Tool and a method for the assembly of a generator

A tool for assembly of an inner enclosure of a generator or a machine comprises a first part and a second part. The first part comprises a plate with one edge constructed to form a first half-ring. The second part comprises a second half-ring corresponding to the first half-ring of the first part. Upon assembly of the first part and the second part, the first half-ring and the second half-ring form a full-ring to encompass a shaft of the generator or the machine and to connect to an inner enclosure of the generator or the machine.

CROSS-REFERENCE TO RELATED APPLICATIONS

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

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.

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

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.

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

Provided is a tool for the assembly of a generator or machine according to claim1. Further, a use of a tool and a method for assembling a generator or machine is provided according to claims6and7, respectively.

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.

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.

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.

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.

Furthermore, a method to assemble a generator or a machine with a tool according to the invention is provided.

DETAILED DESCRIPTION

With reference to the figures like reference numerals designate identical or corresponding parts throughout the several views.

FIG. 1is a schematic perspective view of a tool1according to an example of the invention. Shown is a plate2comprised by a first part10of the tool1in this view below. The plate2of the first part10is 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 part10a curved face projects along the edge of the cut-out. The face has a certain width perpendicular to the plate2and has the shape of a half-ring, the face is denominated as first half-ring11in the following. In the example ofFIG. 1the plate2has three cut-outs25projecting completely through the plate2. Ribs55are connected to the plate2starting from the first half-ring11and projecting with an angle to each other along the plate2. A main function of the ribs55is to provide a stiffness to the plate2. Further, plate2has several holes26, in this example eight holes26distributed along the lower side of the plate2in this perspective, distant to the half-ring cut-out25and the first half-ring11. The holes26serve as a means for establishing a connection to an inner enclosure5,6as will be described below. The tool1comprises a second part20in the view above essentially comprising a second curved face formed as half-ring, in the following denominated as second half-ring13. Regarding size and flection the second half-ring13is similar to the first half-ring11. The first half-ring11and the second half-ring13each comprise connection plates30at each end, as shown inFIG. 1. The connection plates30are formed perpendicular to the end of the half-rings11,13and have the same width as these. Connection plates30have plane faces to be joint in a way that the half-rings11,13being assembled to form a full-ring22. To the end of fixing together the half-rings11,13in a force closure, bores are provided in the connection plates30for including screws33or bolts through the connection plates30of the half-rings11,13. Screw nuts are connected with the screws33to establish a removable connection between the first half-ring11and the second half-ring13of the tool1. InFIG. 1the second part20comprises two ribs55projecting from the two ends of the first half-ring11along a section of the second part20. The first part10and the second part20create a full ring inFIG. 1, which serves for enclosing a shaft41of a generator40or machine40.

FIG. 2shows a draft of a schematic front view of the tool1connected to a part of an inner enclosure5,6. The inner enclosure5,6is a part of the generator40or machine40at one end to essentially close the running parts of the generator40or machine40against the environment. The inner enclosure5,6has a circular shape, inFIG. 2one half of the inner enclosure5is shown. The second half of the inner enclosure6is to be assembled as will be described below. Here, the tool1is put onto the shaft41and the first part10and the second part20of the tool1are assembled to a full-ring similar toFIG. 1and described above.

FIG. 3shows a draft of a schematic front view similar toFIG. 2. Here, the second half of the inner enclosure6is assembled to the full inner enclosure5,6. In this front view the generator40or machine40is put onto the support43, the inner enclosure5,6fills most of the open area in the axial direction of the generator40or machine40and thus in the direction of the shaft41. It is visible inFIG. 3that the tool1is turned down, the first part10of the tool1is directed to the bottom. This is due to the assembling process in which the tool1with the first half of the inner enclosure5is turned to the other side of the shaft41to enable the assembly of the second half of the inner enclosure6as is described below.

FIG. 4shows a perspective schematic view of a generator40or machine40in a first phase of the assembly procedure to assemble the inner enclosure5,6to the generator40or machine40by means of the tool1. The generator40or machine40rests on a support43, commonly fixed to the ground of a generator hall. In this first method step the first part10of the tool1is releasably connected to the first half of the inner enclosure5by means of pins or bolts reaching through the holes26in the plate2of the first part of the tool10. Also shown inFIG. 4is the second half of the inner enclosure6below the first part of the tool10connected to the first half of the inner enclosure5.

FIG. 5shows a second step of manufacturing of the inner enclosure5,6to the generator40or machine40. Here, the first part10of the tool1releasably connected to the first half of the inner enclosure5is assembled to the shaft41of the generator40or machine40. The first part10and the second part20of the tool are bolt together to encompass the shaft41. The half-ring11of the first part10of the tool1abuts the shaft41, there is a gap between the first half5of the inner enclosure5,6and the shaft41. In this view the plate2and the first half5of the inner enclosure5,6are directed upwards. The two parts, the tool1and the first half5of the inner enclosure5,6are typically mounted to the generator40or machine40by a crane.

FIG. 6shows a third step of the method to assemble the inner enclosure5,6to the generator40or machine40. Hereby, the first half5of the inner enclosure5,6as well as the connected tool1are turned by around 180° a half turn around the shaft41by turning the plate2. This means, the plate2and the first half5of the inner enclosure5,6are directed to the bottom now. The upper part of the housing of the generator40or machine40is open in this position in an axial direction, the lower part of the housing is closed by the first half5of the inner enclosure5,6.

FIG. 7shows a fourth step of the fabrication method by means of the tool1. In this step a second half6of the inner enclosure5,6is carried to the generator40or machine40according toFIG. 6. This is usually done by a crane because of the high weight of the parts involved in medium or high power generators40or machines40. The second half6of the inner enclosure5,6is attached flush with the first half5, so the two parts constitute a full circle or full-ring22, which is the complete inner enclosure5,6. It is to be understood that in an example of the invention the inner enclosure5,6is prefabricated out of the first half5and the second half6. The fabrication step is shown inFIG. 8, at which the two halves5,6are connected to each other in a common way. At this step the inner enclosure5,6is completely assembled with the generator40or machine40. The inner enclosure5,6is assembled supported by the tool1as described. The tool1arranges for a secure introduction, a smooth adjustment of the two halves5,6of the inner enclosure5,6and an improved manufacturing process. In this assembled condition the clearance between heavy fan blades of the rotor of the generator40and the inner enclosure5is about 2-3 mm.

FIG. 9shows a sixth step of the manufacturing method using the tool1. The tool1is turned by an angle of around 45°, so the plate2is directed to a side of the generator40or machine40. The tool1is divided into its first part10and second part20by loosening the screws33and removing the parts10,20.

Modifications and variants in addition to those already stated are possible.

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.