EP1529332A1

EP1529332A1 - Rotor for an electric machine

Info

Publication number: EP1529332A1
Application number: EP03739953A
Authority: EP
Inventors: Alain Lacaze
Original assignee: Alstom Technology AG
Current assignee: General Electric Technology GmbH
Priority date: 2002-08-16
Filing date: 2003-07-30
Publication date: 2005-05-11
Also published as: CH695973A5; AU2003285623A1; JP4431037B2; US20050184614A1; WO2004017493A1; JP2005536175A; CN1698248B; US7342341B2; CN1698248A

Abstract

The invention relates to a rotor (14) for an electrically rotating machine, comprising a rotor core (5) having axial slots (9) for receiving axial conductors (13), and a method for assembling such a rotor. The aim of the invention is to build a very stable and reliable rotor while creating a high field. Said aim is achieved by disposing first means (10) on the axial slots (9) and arranging corresponding second means (18) on the axial conductors (13). The first means (10) and the second means (18) effectively cooperate with each other in order to fix the axial conductors (13) in the axial slots (9) particularly in relation to centrifugal and torsional forces. Conductors are normally inserted into slots from a radial direction and are then fixed therein with the aid of special means of the conductors. However, the special configuration of the inventive rotor within the slots and the corresponding configuration of the conductors allow the conductors to be assembled in a simple and direct manner in the rotor core, rendering additional fixing means unnecessary.

Description

Rotor for an electrical machine

TECHNICAL AREA

The present invention relates to a rotor for a rotating electrical machine comprising a rotor core with axial slots for receiving conductors. It also relates to a method for assembling such a rotor.

STATE OF THE ART

The rotating field of an electrical rotating machine is generated by a rotor core which has grooves into which windings of electrical conductors are inserted. Such a rotor core is normally made of steel, while the windings are made of copper or another electrically conductive material. The field is generated by driving these windings with a direct current, which is either generated separately and then contacted with the conductors via brushes on the shaft of the rotor, or which is generated directly on the shaft in a so-called brushless excitation.

As a result of the high centrifugal forces that must be borne by such a rotor and its components, it is extremely important to firmly attach the conductors to the rotor core. At the same time, it is also important to ensure efficient cooling of these conductors due to the heat generated in the conductors during operation.

A rotor is normally produced accordingly by providing grooves, by inserting the conductors into these grooves from the radial direction and by Then, on the radially outer, peripheral side, these grooves are closed with the help of wedges or rings, thereby simultaneously fixing the conductors in relation to centrifugal forces. The stack of conductors is retained in the radial direction by these wedges or rings. The cooling of such arrangements is achieved either by leaving gaps between the conductors and the side walls of the grooves, or by arranging axial and / or radial holes in the conductor or between the conductors through which cooling gas is circulated. Such an arrangement is e.g. B. in CH 638349 or in CH 649422.

PRESENTATION OF THE INVENTION

Accordingly, the objective problem underlying the present invention is to provide an alternative, simple and reliable rotor construction in which the conductors of the windings are well fixed and which is capable of generating high fields. This is for a rotor for a rotating electrical machine with cutouts between the poles for receiving axial conductors.

The present invention solves the aforementioned problem in that axial slots are formed in the recesses to form first means, and in that the axial conductors are formed with corresponding second means, the first means and the second means being operatively connected so that the axial conductors be fixed in the axial slots, in particular with regard to centrifugal and torsional forces.

The present invention accordingly relates to a rotor according to claim 1 and a method according to claim 14.

The essence of the present invention is accordingly, instead of simply inserting the conductors into grooves in the rotor core, structuring the cutouts through the slots mentioned, wherein first means are provided in these slots, which allow direct fastening of the axial conductors. To make this possible, the leaders are speaking structured with second means which, by interacting with the first means, allow the conductors to be fixed directly in the slots. While according to the prior art the conductors are normally fixed in the grooves by providing special wedges or rings which are inserted on top of the conductors (peripheral side), and which wedges / rings correspond to the total centrifugal load, which at In this case, the centrifugal load during operation of the rotor is carried directly by interaction of the first means with the second means. Accordingly, no additional parts such as wedges or rings are required, which reduces the costs and, moreover, as a result of the direct fixing of the conductors to the rotor core, a simple, robust construction can be provided which is simple to assemble and maintain. Furthermore, the conductors will have a larger cross section than normal, which allows low-voltage insulation. The insulation between adjacent conductors, which are arranged in adjacent slots, can be ensured by an air gap / slot through which cooling air is guided.

In a first preferred embodiment of the present invention, the first means are designed in the form of shoulders in the slots. These shoulders have at least one surface which allows the second means to rest in the radial direction, which gives a direct possibility of absorbing the centrifugal force which acts on the conductors. These shoulders preferably extend essentially along the entire axial slots (by preferably providing surfaces which are tangential to the axis of the shaft) and are preferably arranged symmetrically on both sides of these slots. Accordingly, the second means are designed to interact with these shoulders in the shooters. The second means are in the form of recesses (or shoulders) in the axial conductors, which in turn come to rest on the shoulders of the slots. These cutouts preferably extend essentially along the entire axial conductor and are preferably arranged symmetrically on both sides of these axial conductors. A particularly simple construction is possible if the first and second means are arranged close to the shaft, ie close to the bottom of these recesses between the pole zones. This is for example possible if, as preferred, the recesses in the conductors are arranged in the radially inner area (with respect to the rotor) of the axial conductors, and accordingly the shoulders! are arranged in the slots near the bottom of the recesses of the rotor, ie close to the axis of the rotor. The axial conductors can then protrude essentially from these slots into the cutouts (free-standing conductors) and end flush with the diameter which corresponds to the outside diameter of the pole zones. A space remains in the peripheral, protruding region of the conductors between adjacent conductors in adjacent slots.

Another preferred embodiment of the present invention is characterized in that the axial slots are designed as dovetail slots in the rotor core (T-shaped or V-shaped or similar), and that the axial conductors have a corresponding dovetail area (correspondingly also T-shaped or V-shaped or similar), which fits into said dovetail slots. In particular, T-shaped slots, i. H. Slots with two symmetrical shoulders on both sides can easily be made from a forged shaft and allow the ladder to be securely and firmly attached. The corresponding T-shape on the conductors can also be easily milled or pulled.

A very particularly simple embodiment is characterized in that in each case a single axial conductor is arranged in an axial slot (according to the prior art, a plurality of conductors are normally arranged in a groove), and that the radial height (ie in the radial direction) is particularly preferred the axial conductor is considerably larger than its circumferential width (which corresponds at least in the lower part essentially to the width of the slot). Preferably, the conductors have a trapezoidal shape, i.e. H. the axial conductor is narrower on the radially inner side on the radially outer side. A single conductor is then only arranged in the radial direction for a given angular position of the rotor.

Another particularly simple construction of a rotor according to the invention allows the axial conductors in the rotor core to be inserted into the axial slots in an axial direction with respect to the rotor. This is particularly the case when the first means and the second means run along the entire slot and along the entire line. E s ¬

ters extend, which on the one hand allows a firm and direct contact between the rotor core and the conductors, and at the same time enables simple manufacture and assembly.

Another preferred embodiment of the present invention is characterized in that the depth of the axial slots is substantially smaller than the free-standing radial height of the axial conductors, i.e. H. that the axial conductors protrude from the slots in the rotor core into those areas where the recesses for the conductors are located. Preferably, these protruding portions of the axial conductors, between which a deep space remains (which ensures electrical insulation and allows the circulation of cooling air) are fixed in this situation relative to each other and also with respect to the poles of the rotor core, where no conductors are arranged. This is achieved in that third means are arranged on the radially outer side between adjacent axial conductors in order to keep them at a certain distance and to stabilize these conductors in the circumferential direction.

Preferably, the third means are in the form of wedges or rods which interact with recesses provided in the axial conductors, these wedges preferably extending substantially along the length of the axial conductors, so that axial channels between the rotor core and the wedges remain for the circulation of cooling air. Optionally, the wedges additionally have radial bores or are partially interrupted in order to allow at least partial circulation of cooling air in the radial direction. This design allows a particularly efficient cooling of the rotor.

With regard to the material from which the axial conductors and their end connections are made, aluminum or copper come into question or alloys based on at least one of these metals. A single axial conductor is preferably arranged in an axial slot, an axial conductor having a cross section in the range from 1000 to 4500 mm ² , preferably in the range from 2000 to 4000 mm ² .

In another preferred embodiment of the present invention, conductor-free zones (pole zones) are arranged on the rotor, around which the conductors are wound in at least one winding, the axial regions of the windings being called axial conductors are formed, which are arranged in said axial slots, and wherein the radial regions of the windings are formed by at least one end connection (usually in the form of a ring segment) which are arranged at the end outside of the pole zones, ie adjacent to these. This at least one end connection is also provided with second means for interacting with the first means in order to fix the end connections in the axial contactors, in particular with regard to centrifugal and torsional forces. The slots in the rotor core are longer than the axial conductors, which also makes it possible to fasten the end connections in these slots with the aid of the shoulders which are provided in the slots. Fastening the end connections in a manner analogous to that of the axial conductors has the advantage that displacements of conductors (both axial conductors and end connections) as a result of rotational forces or torsional forces are the same for both the axial conductors and the end connections. This avoids loads on the connections between the end connections and the axial conductors. In order to improve the stabilization of these end connections, it is possible to additionally arrange further axial slots with first means on the end outside the conductor-free zones, with further second means correspondingly being arranged on the at least one end connection. These first means are preferably designed in the form of shoulders, as described above, which preferably extend symmetrically on both sides of the slots. Accordingly, the second means are designed in the form of corresponding recesses, which run perpendicular to the main direction of the end connections, in projections (which are arranged on the shaft side on the ring segment) of the end connections.

A particularly simple construction of the end connections is also possible if these end connections are individual conductors with the same height as the individual (per slot) axial conductors, the radial height of the end connections preferably being substantially greater than their axial width. If there is only one winding, only one end connection is required on each side of the pole zones, if there are several windings, the end connections are arranged parallel to one another and perpendicular to the main axis of the shaft. According to a further preferred embodiment of the present invention, the end connections are conductively connected to the axial conductors with the aid of pins or screws. The connection can also be welded, brazed or glued, preferably with the aid of a conductive adhesive. Combinations of the connecting means mentioned can also be used. For example, the combination of pins or screws with a conductive adhesive can enable a particularly simple and reliable connection between the end connections and the axial conductors.

Not only are the axial conductors pushed into the rotor core from the axial direction, but the end connections can also be pushed into the axial slots from the axial direction in the rotor core.

Further preferred embodiments of the present invention are described in the dependent claims.

The present invention also relates to a method for assembling a rotor as described above. This method is characterized in that individual solid axial conductors are inserted into the axial slots in the rotor core from the axial direction. This assembly is particularly simple and inherently provides a very stable connection between the rotor core and the conductors. The axial conductors can additionally be fixed in the slots with the aid of wedges or inflatable tubes which connect the shoulders of the second means, which are provided on the axial conductors, to the corresponding first means, i. H. z. B. also shoulders, which are arranged at the slots of the rotor core, press. This results in a preload against the centrifugal forces. Because of the small number of parts and because no special tools are required, such an assembly can also be easily carried out on site, the conductors and the rotor core then being supplied separately.

Another preferred embodiment of the method according to the invention is characterized in that individual solid axial conductors and end connections are inserted step by step in the rotor core in the axial direction with respect to the rotor into the axial slots. The axial conductors and the end Connections are conductively connected to each other after each step, so that successive windings form around the conductor-free areas of the rotor. An axial conductor is gradually inserted into the corresponding slot next to the pole zone of the rotor core, then a corresponding end connection with an angular (circumferential) extension, so that the end of the axial conductor abuts the inner surface of the end connections, into the axial slots inserted in the axial direction. The axial conductor is then electrically connected to the end connection, be it by bolting, brazing, welding (e.g. MIG, TIG, electron beam welding, laser welding etc.), gluing (conductive adhesive) or screwing etc. or combinations thereof are used. If this is necessary, third means can be inserted in the radially outer region of the axial conductors between adjacent axial conductors from the axial direction with respect to the rotor, in order to keep the axial conductors at a certain distance and to stabilize these axial conductors in the circumferential direction.

Further embodiments of the method according to the present invention are described in the dependent claims.

BRIEF EXPLANATION OF THE FIGURES

In the accompanying figures, preferred embodiments of the invention are shown, wherein

1 is a perspective view of a forged blank;

Figure 2a) is a perspective view of a machined forged rotor; b) is a side view of the shaft; c) is a section along the line A-A in Fig. 2b); d) is a section along the line B-B in Fig. 2b); e) is a section along the line C-C in Fig. 2b); f) is a section corresponding to D in Fig. 2c); g) is a section corresponding to E in Fig. 2 e);

3 a) is a perspective view of a rotor with the first end connection inserted; b) is a perspective view of the collector rings with the conductors connecting them to the end connections; Fig. 4 a) is a perspective view of a rotor with all axial conductors and

End connections inserted; b) is a side view of a rotor with all axial conductors and end connections inserted;

Fig. 5 is a perspective view of a section of Fig. 4;

Fig. 6 is an axial section through an axial conductor; and

Fig. 7 shows an axial section through the rotor with all axial conductors inserted and an end connection (above) inserted.

WAYS OF CARRYING OUT THE INVENTION

With reference to the drawings, which serve to illustrate and not to limit the present preferred embodiments of the invention, Fig. 1 shows a perspective view of a forged tube of a rotor 1 which has not yet been machined, i.e., has not been machined. H. without slots. One can already see the drive end 2 of the shaft, at which the coupling to the turbine is arranged. At the other end of the shaft is the so-called non-drive end 3 of the shaft, where the exciter or the slip rings are usually arranged. The conductor-free areas or pole zones 4 of the rotor can already be seen in the central area. The rotor core is made of steel.

Fig. 2 shows the rotor core 5 after it has been machined. FIG. 2a shows a perspective view of the rotor core 5, while FIG. 2b) shows a side view of such a rotor core 5. In the central area there are two pole zones 4 which remain free of conductors and around which the windings of the conductors are wound. Depending on the number of poles, there may also be 4, 6 etc. such conductor-free regions 4. Two recesses 8 are arranged between these conductor-free regions 4, in which the axial conductors come to lie. At the end of the shaft directly next to the conductor-free areas 4, the area of the end connections at the drive end 6 and the area of the end connections at the non-drive end 7 are arranged. The cutouts 8 for the axial conductors and also the end regions 6 and 7 are provided with axial slots. The length a of the entire shaft is carries 5100 mm, the length s of the pole zones is approximately 2400 mm.

Fig. 2 c) shows a section along the line A-A in Fig. 2b), i. H. a section orthogonal to the axis of the shaft through the area of the end connections at the drive end. The axial slots 9, which extend along the entire central region of the rotor core, that is to say both in the cutouts 8 for the axial conductors and in the regions 6 and 7, are designed as dovetail slots. The shorter slots 24, which only extend in the area of the end connections at the drive end 6, have the same cross section. Fig. 2f) shows the detail D as indicated in Fig. 2c). The contactors 9 have a width h of 22 mm, which narrows to a width i of 13 mm at the exit of the slot. Accordingly, there are two symmetrical shoulders 10 on each side of the slot. The thickness 1 of these shoulders in the radial direction is 10 mm. There is a wall of width k of 5.9 mm between the slots and a slot is arranged every five degrees, i. H. around the entire circumference there are 72 contactors 9.

Fig. 2d) shows a section along the line BB in Fig. 2b) orthogonal to the axis of the shaft. It can be seen here that in the central region there are only contactors 9 in the cutouts 8 for the axial conductors. The diameter e in the region of the recesses 8 is 660 mm, while it is 900 mm in the conductor-free areas. Fig. 2e) shows a section along the line CC in Fig. 2b). The corresponding section E is shown in Fig. 2g). In the area of the end connections at the non-drive end 7, the slots 9 are formed deeper around the entire circumference of the shaft. This can be seen in Fig. 2g), where the depth g of the slot is 40 mm. Apart from the depth, these slots have the same geometry as those shown in Fig. 2f). The greater depth of the slots can be used to connect the innermost winding of the conductor (in particular the innermost end connection) to the exciter, which is arranged at the non-drive end 3 of the shaft. In addition, the deeper slots can be used to supply cooling air in the axial direction to the central area of the rotor core when the conductors are inserted into the slots. If this is provided, the slots at the drive end 2 can also be made deeper. FIG. 3 shows a perspective view of a rotor core, in which the first axial conductor (not visible, hidden behind the upper conductor-free region 4) is inserted into the first slot 9 immediately next to the conductor-free region 4. The connection between the axial conductors and the end connections is preferably reactivated such that the end of the axial conductor abuts a side face of an end connection.

In addition, the first end connection 11 is inserted into the contactors 24 in the region of the end connections at the non-drive end 7 of the rotor. The first end connection 11 has an angular (circumferential) extension, which on one side (on the side facing the viewer) is flush with the side of the conductor-free area 4, while on the other side (not visible) it stops the end face of the axial conductor with the side surface of the end connection 11. The end connection 11 has small projections on the inner radius which fit into the slots 24 and which fasten the end connection 11 to the rotor core. Also visible in FIG. 3 are the collector rings 12, which are electrically connected to the windings of the conductors. In particular, one of these rings 12 is connected to the first end connection 11 by arranging conductors in the deep slots as mentioned above.

3b) shows how the rings 12 are connected to the poles of the windings by means of conductors, which are arranged in the deep slots 25, with the end connections 11.

In order to additionally fasten the end connections with respect to centrifugal forces, it is possible to provide circumferential grooves on the peripheral side of the end connections, and to insert circumferential retaining rings into these grooves after the rotor has been completely assembled. These retaining rings can be metal cables or fiber-reinforced plastic strands, which can even be cast directly into these grooves when assembling, by inserting strands of reinforcing material (carbon fibers, glass fibers, aramid fibers, etc.) and adding matrix material.

The electrical and mechanical connection between the axial conductors and the end connections (both made of copper or aluminum), whereby both conductors have individual cables. ter are (no stack of conductors), which have a height that corresponds essentially to the difference in radius between the conductor-free areas 4 and the recesses 8 for the conductors, is realized by welding, pins, bolts, screws or combinations thereof. A combination of pins / bolts with an electrically conductive adhesive is particularly suitable. The use of an adhesive allows a much easier assembly and provides a sufficient electrical connection between the conductors. Possible electrically conductive adhesives are listed in Table 1.

Table 1: conductive glue for connecting the conductors.

Fig. 4a) shows a fully assembled rotor 14 in a perspective view and Fig. 4b) in a side view, wherein all axial conductors 13 and all end connections 11 are inserted. The tight packing of the conductors 11, 13, which form the windings around the conductor-free zones 4 on both sides, can be recognized. The individual conductors can be insulated from one another by a lacquer layer or by an insulating surface layer, and in particular air gaps can be provided between the conductors, which allow the circulation of cooling air in the axial or radial direction. 5 shows a detailed perspective view of the area of the end connections at the drive end 6. At the non-drive end 3 of the shaft (for an even number of windings, this would be on the drive side 2 for an odd number of windings) there is a full 360 degree connecting ring 26 for the poles, which is only half as wide as it is two creates symmetrical paths. This is the connection that connects the conductors located on the central plane. This ring 26 ensures the connection between the two poles of the rotor windings (Fig. 4a).

Fig. 6 shows an axial section through an axial conductor 13. The axial conductor has a conical shape, i. H. its width n on the inner side, on the side close to the central axis of the shaft, is 18.5 mm, while the width w on the peripheral side is 31.3 mm. At a distance of approximately o = 15 mm from the lower end there is a recess 18 on both sides of the conductor which are intended to interact with the shoulders 10 of the rotor core. The recess 18 is located between the lower part 17 and the middle part 19 of the conductor 13. In the radial direction, these recesses have a width p of 12 mm, which leaves a central solid width q of the conductor of 11 mm.

Between the middle part 19 and the upper part 21 of the conductor there is another pair of recesses 20 on both sides of the conductor 13. These recesses are spaced from the upper edge of the conductor by u - 8 mm and have a width v in the radial direction of 6 mm. After the conductor 13 has been inserted in the axial direction into the rotor core, or rather into the axial slots 9 of the rotor core, adjacent conductors are spaced apart from one another, with an air gap remaining between them, which extends in the radial direction (cf. FIG. 7). In order to fasten the individual axial conductors to one another in the circumferential direction and to ensure a controlled circulation of cooling air between the individual, parallel conductors, axially extending wedges or rods 22 are also inserted between the conductors 13 from the axial direction, using the cutouts 20 become. This is shown in the left part of FIG. 7. The axial channels 23 thereby provided between the conductors (and the conductors and the conductor-free area 4 of the rotor core at the edge of the cutouts 8) allow cooling air to be circulated in the axial direction. If the wedges 22 also have holes in the radial direction cooling air, which circulates in these axial channels, can be at least partially diverted in the radial direction.

In this special case, the conductor 13 is not structured any further, but it is also possible to provide axial cooling holes in the conductors in order to allow the conductor to be centrally cooled.

In addition, it is possible to use such a rotor for assembling a superconducting rotor.

Of course, the 2-pole arrangement as described here should not limit the scope of the idea. Higher numbers of poles can also be easily realized.

LIST OF REFERENCE NUMBERS

1 forged blank of the rotor

2 drive end of the shaft

3 Non-drive end of the shaft

4 conductor-free areas or pole zones of the rotor

5 rotor core

6 Area of the end connections at the drive end Area of the end connections at the non-drive end

8 recess for the axial conductor axial dovetail slots

10 shoulder of 9

11 end connection

12 rotating rings, collector rings

13 axial conductors

14 rotor Dovetail area of the end connections Recesses between 15 dovetail area of 13 lower cutout of 13 middle area of 13 upper cutout of 13 head area of 13 wedge axial / radial channel for coolant (gaseous or liquid, e.g. cooling air) axial slots for the end connections recessed slot for the supply of coolant connection ring for the poles

Claims

PATENT CLAIMS

1. Rotor (14) for a rotating electrical machine comprising a rotor core (5) with axial slots (9) for receiving conductors (13), characterized in that the axial slots (9) with the formation of first means (10) are formed, and that the axial conductors (13) are formed with corresponding second means (18), the first means (10) and the second means (18) being operatively connected so that the axial conductors (13) are in the axial slots (9) in particular with regard to centrifugal and torsional forces.

2. Rotor (14) according to claim 1, characterized in that the first means are designed in the form of shoulders (10), these shoulders (10) preferably essentially along the entire axial slots (9) and preferably symmetrically on both Sides of these slots (9) extend in such a way that the second means are designed in the form of recesses (18) in the axial conductors (13), which preferably extend essentially along the entire axial conductors (13) and preferably symmetrically on both sides of these axial ones Extend conductors (13), the recesses (18) preferably being arranged in the radially inner region of the axial conductors (13).

3. Rotor (14) according to one of the preceding claims, characterized in that the axial slots (9) are designed as dovetail slots (9, 10) in the rotor core (5), and that the axial conductors (13) have a corresponding dovetail area ( 17) which fit into said dovetail slots (9).

4. Rotor (14) according to any one of the preceding claims, characterized in that in each case a single axial conductor (13) is arranged in an axial contactor (9), and that the radial height (s) of the axial conductor (13) is substantially large - ser than their circumferential width (n, w), preferably this width (n) on the radially inner side of the axial conductor (13) is narrower than the width (w) on the radially outer side of the axial conductor (13).

5. Rotor (14) according to any one of the preceding claims, characterized in that the axial conductors (13) in the rotor core (5) in the axial slots (9) can be inserted in an axial direction with respect to the rotor.

6. rotor (14) according to any one of the preceding claims, characterized in that the depth (f, g) of the axial slots (9) is substantially smaller than the radial height (s) of the axial conductor (13) and that on the radial outer side of the axial conductors (13) third means (22) are arranged between adjacent axial conductors (13) to keep them at a certain distance and to stabilize these conductors (13) in the circumferential direction.

7. rotor (14) according to claim 6, characterized in that the third means are designed in the form of wedges (22) which interact with recesses (20) which are provided in the axial conductors (13), preferably these Wedges (22) extend along the length of the axial conductors (13), axial channels (23) for the circulation of cooling air remaining between the rotor core (5) and the wedges (22) and optionally the wedges (22) additionally have radial bores have, which allow an at least partial circulation of the cooling air in the radial direction.

8. rotor (14) according to any one of the preceding claims, characterized in that the axial conductors (13) are made of aluminum or copper, and that preferably a single axial conductor (13) is arranged in an axial slot (9), wherein an axial conductor (13) has a cross section in the range from 1000 to 4500 mm, preferably in the range from 2000 to 4000 mm.

9. Rotor (14) according to one of the preceding claims, characterized in that conductor-free zones (4) are arranged on the rotor, around which the conductors (11, 13) are wound in at least one winding, that the axial regions of the Windings are formed by the axial conductors (13), which are arranged in the axial slots (9), that the radial regions of the windings are formed by at least one end connection (11), which are arranged on the end outside of the conductor-free zones (4), and that at least one of these end connections (11) is also provided with second means (18) for interacting with the first means (10) in order to fix the end connections (11) in the axial slots (9), in particular with regard to centrifugal and torsional forces ,

10. The rotor (14) according to claim 9, characterized in that additional axial slots (24) with first means (10) are arranged at the ends (6, 7) outside the conductor-free zones (4), and in that further second means (18 ) are arranged on the at least one end connection (11), the first means being designed in the form of shoulders (10) which preferably extend symmetrically on both sides of the slots (24), and the second means being in the form of corresponding, Recesses (18) extending perpendicular to the main direction of the end connections (11) are formed in projections of the end connections (11).

11. Rotor (14) according to one of claims 9 or 10, characterized in that the end connections (11) are individual conductors with the same height as the individual axial conductors (13), and that the radial height of the end connections (11) is substantially greater is as their axial width.

12. Rotor (14) according to any one of claims 9 to 11, characterized in that the end connections (11) are conductively connected to the axial conductors (13) with the aid of pins, screws, welding, brazing, gluing, preferably with the aid of a conductive adhesive, or combinations of these connecting means.

13. Rotor according to one of claims 9 to 12, characterized in that the end connections (11) from the axial direction in the rotor core (5) in the axial Contactors (9, 24) can be pushed.

14. Rotor (14) according to any one of the preceding claims, characterized in that the axial slots (9) are at least partially deeper than the foot regions (17) of the axial conductors (13), so that recessed slots (25) remain, through which coolant can be guided or in which conductors can be inserted, which do not belong directly to the windings.

15. A method for assembling a rotor (14) according to any one of the preceding claims, characterized in that individual solid axial conductors (13) are inserted from the axial direction into the rotor core (15) into the axial slots (9).

16. The method according to claim 15 for assembling a rotor according to one of claims 9 to 14, characterized in that alternately individual solid axial conductors (13) and end connections (11) gradually in the rotor core (5) in the axial direction with respect to the rotor in the axial contactors (9, 24) are inserted, the axial conductors (13) and the end connections (11) being conductively connected to one another after each step, so that successive windings form around the conductor-free regions (4) of the rotor, and optionally in the radial direction outer area of the axial conductors (13) third means (22) are inserted between adjacent axial conductors (13) from the axial direction with respect to the rotor in order to keep the axial conductors (13) at a certain distance and around these axial conductors (13) stabilize in the circumferential direction.

17. The method according spoke 16, characterized in that the end connections (11) are conductively connected to the axial conductors (13) with the aid of pins, screws, welding, preferably using MIG or TIG, gluing, preferably with the aid of a conductive Glue, or combinations of these connecting means.