WO2012061856A2

WO2012061856A2 - Winding overhang support of a generator

Info

Publication number: WO2012061856A2
Application number: PCT/AT2011/000440
Authority: WO
Inventors: David Lerchbaum; Günther MUSSBACHER
Original assignee: Andritz Hydro Gmbh
Priority date: 2010-11-10
Filing date: 2011-10-31
Publication date: 2012-05-18
Also published as: AT510678A1; WO2012061856A3

Abstract

The present invention relates to a winding overhang support for the rotor (1) of an electric generator, comprising at least one ring (4), which absorbs the centrifugal forces of the windings (3) in the winding overhang area. According to the invention, the ring (4) is produced from a composite material, wherein the ring is produced before the ring (4) is installed. The present invention further relates to a corresponding method for producing a winding overhang support for a generator.

Description

Winding head support for a generator

The subject of this invention forms a

Winding head support for the rotor of an electric

Generator having at least one ring which receives the centrifugal forces of the windings in the winding head area.

The subject of this invention also forms

corresponding method for producing a

Winding head support for a generator.

In electric generators, in particular at

Synchronous machines, the centrifugal forces must

Rotor windings are added to prevent undue deformation of the windings. This happens in the rotor ball area via slot wedges, which initiate the forces in the rotor bale.

The centrifugal forces in the winding head area are in

conventional generators via rotor caps made of steel or, in the case of smaller machines, by means of taped bands of glass or carbon fiber composites. The occurring centrifugal forces are among others of the

Speed of the rotor dependent. The speed is determined by the number of pole pairs of the rotor and the required power frequency.

Depending on the cooling concept, the steel cap can also use the

Take over the function of the ventilation of the winding overhang. This then takes place via radial bores in the steel cap. In order to prevent losses and heating of the rotor cap, these rotor caps must also made of non-magnetic

Material to be made.

Due to the demand for non-magnetic behavior and the high required strength, these are Steel caps made of nonmagnetic work hardened austenite. As a result, only the material costs of these steel caps cause a considerable proportion of the

Total cost. In addition, the drilling of the

Ventilation holes in the high-strength steel cap high

Costs.

For smaller generators (up to approx. 9 MW) the bandage design is currently used. This bandages are made

Fiberglass polyester resin composite wound on the rotor winding head. Subsequently, the rotor is heated in an oven, wherein the matrix material (e.g., polyester resin) first liquefies and then cures to join the individual bandages. This creates a ring of composite material. To compensate for the loss of thickness occurring, the bandages must be wound up under a relatively high bias. In addition, one uses an elongated slot wedge, on the one hand fixes the bandages axially and on the other hand pressure peaks of the

Copper winding absorbs without damaging the bandages.

Since the bandaging already a bias in the

Material must be introduced to compensate for the loss of thickness, is only the reduced by this bias strength of the bandage for receiving the Wickelkopffliehkräfte available. At the same time, the maximum height and therefore the cross section of the bandage are limited by the loss of thickness and the prestressing, so that this design variant can only be used up to limited centrifugal forces. The invention is therefore based on the object, a

To provide winding head support, on the one hand cost in the production and on the other hand, easy to install and still high centrifugal forces

withstand.

This object is achieved by a winding head support with at least one ring made of composite material, wherein the at least one ring is made prior to its mounting on the winding head.

So instead of winding the composite material on the rotor and then curing it, the multi-phase cured ring is made of composite materials and then applied to the rotor. Since the ring is no longer made on the rotor, this can be wound almost without bias, so that almost the entire strength of the ring is available for receiving the winding forces.

When winding the rings separately from the machine, it is possible to optimize the effect of loss of thickness and thus produce higher rings with a large cross-section.

This makes it possible to use these rings even for large machines, which are currently still made with expensive steel caps.

It is advantageous if the winding head support has a plurality of rings made of composite material. These individual rings can be spaced apart by spacers in the axial direction. The cooling air can then be passed between the individual rings. In addition, the spacers can be integrated into the rings, resulting in a reduction in manufacturing complexity. If the entire winding head support consists of several identical rings, results in a high lot size in the

Manufacturing, so that a series process for the

Ring production can be developed. This reduces the cost of each ring at the same time higher

Process security.

Preferably, a resin-impregnated felt or a felt-like material is arranged between the at least one ring or the rings and the winding overhang. The felt and the impregnating resin take over the function of the connection between the ring or the rings and the windings. You can also connect several rings with each other.

By attaching a preimpregnated felt to the inside of the rings is a simplified

Manufacturing process without full impregnation of the rotor possible. It is favorable if a pressure-tip-resistant layer is attached to the ring on its inside, which has a higher pressure peak resistance than the composite material of the ring. This layer consists for example of hard tissue and has the function of damaging the composite material of the ring by pressure peaks of

To prevent windings, and in the case of an electrically conductive composite material (for example carbon fiber) an electrical insulation layer between winding and

Produce composite material. In addition, spacers can be incorporated in this layer, which define an axial distancing of the individual rings.

The composite material or the composite material is

preferably a glass, aramid or carbon fiber composite. 0

The invention also provides a method for producing a winding head support for a generator, wherein the winding head support at least one ring

having. According to the invention, the at least one ring is made of a composite material before being mounted on the rotor.

It is advantageous if the at least one ring is made with optimized bias, so that almost the entire strength of the ring for receiving the

Winding forces is available.

The following is an embodiment of the

winding head support according to the invention by means of

Drawings described. Show it:

Fig. 1 is a schematic sectional view through the

Winding head of a generator;

2 shows a cross section through a single ring.

In the individual figures, the same reference numerals designate the same components.

FIG. 1 shows an embodiment of the invention

inventive winding head support shown with multiple rings 4 made of composite material.

The individual windings 3 of the rotor 1 run in the

Roterballen 5 in the axial direction and are secured by slot wedges against the centrifugal forces. In the area of

Winding head 2, the windings 3 are deflected in a known manner. The individual windings 3 are in present example on a winding support 8, which in turn is welded to a rib 6 of the rotor shaft. Outside the winding head 2 is an end plate. 7

The centrifugal forces in the winding head area are absorbed by the rings 4, in the present example, a total of seven rings 4 are provided, wherein the respective outside

lying rings 4 slightly wider than the inner ring 4 are executed. The individual rings 4 are made of a composite material, for example of glass fibers or carbon fibers, which are connected to one another via a resin. The production of the rings 4 takes place individually in a separate step before mounting the rings 4 on the

Winding head 2. In this case, for example, individual layers of resin-impregnated carbon fibers or glass fibers are wound over a corresponding mold and then cured in an oven.

Between the individual rings 4 and the windings 3, on the one hand, a resin-impregnated felt 9 and

on the other hand, a pressure-tip-resistant layer 10 of hard tissue arranged. The felt 9 ensures on the one hand for a good connection of the rings 4 with each other and on the other hand for a good connection between the rings 4 and the winding head 2. The felt 9 may have 4 holes in the area between the individual rings, so that cooling air through the holes and through the Ring space can flow through. The hard tissue consists for example of several layers of a textile linen or cotton fabric, which is glued with a thermoset phenolic resin.

The pressure spike resistant layer 10 has greater pressure tip resistance than the composite of FIG This layer 10 thus protects the composite material of the rings 4, which can absorb high tensile forces in the rule, but sensitive to pressure peaks of the

Windings is ..

Fig. 2 shows a cross section through a single ring 4 made of composite material. You can see that well

Pressure spike resistant layer 10, which at the

Ring inside 13 is attached and the felt 9, which is impregnated with resin. In addition, the spacer 11

shown, which provides for an axial spacing of the individual rings 4 with each other. The spacer 11 is here directly in the pressure-tip resistant layer 10th

incorporated.

The embodiments shown in the drawings represent only a preferred embodiment of the invention. The invention also includes other embodiments in which, for example, only one ring 4 made of composite material is used.

Claims

claims

1. winding head support for the rotor (1) a

electric generator with at least one ring (4), which receives the centrifugal forces of the windings (3) in the winding head region, characterized in that the ring (4) is made of a composite material and that this

Manufacturing before assembly of the ring (4) is done.

Second winding head support according to claim 1, characterized

characterized in that the winding head support comprises a plurality of rings (4) made of composite material.

3. winding head support according to claim 2, characterized

characterized in that the individual rings (4) over

Spacers (11) are spaced from each other.

4. winding head support according to one of claims 1 to 3, characterized in that between the at least one ring (4) and the winding head (2) a resin-impregnated felt (9) is arranged.

5. winding head support according to one of the preceding claims 1 to 4, characterized in that on

at least one ring (4) on its inner side (13) a pressure spike resistant layer (10) is mounted, which has a higher pressure peak resistance than the

Composite of the ring (4).

6. winding head support according to one of the preceding claims 1 to 5, characterized in that the

Composite is a glass, aramid or carbon fiber composite.

7. A method for producing a winding head support for a generator, wherein the winding head support at least one ring (4), characterized in that the at least one ring (4) is made prior to its mounting on the rotor (1) made of a composite material.

8. The method according to claim 7, characterized in that the at least one ring (4) is made at least partially almost free of bias, so that almost the entire strength of the ring (4) for receiving the

Winding forces is available.