DE102008016758A1 - Cooled stator for e.g. generator, has distance bars used as bar sections and turbulence elements for local increase of heat transfer between cooling agent and stator, where bar sections and elements are provided in gaps in area of teeth - Google Patents

Abstract

The stator has radial winding grooves (14) distributed at an inner circumference and separated by teeth (13). Gaps conducting a cooling agent e.g. cooling air, are formed between stator plates (11) in certain distances by inserting distance bars (16-18) extending in a radial direction and lying in a plane perpendicular to a machine axis. Bar sections (17b, 18b) and turbulence elements are provided in the gaps in an area of the teeth. The bars are used as the bar sections and the turbulence elements for local increase of heat transfer between the cooling agent and the stator.

Description

TECHNICAL AREA

The The present invention relates to the field of electrical Machinery. It concerns a stator for an electric Machine, such as a generator or a motor, according to the preamble of claim 1 and an electric machine with such a stator.

STATE OF THE ART

In the stator of electric machines (generators or motors), as for example from the publication EP-A2-0 899 856 are known, heat is generated during operation, which is removed from a certain size of the machine via special ventilation plates. These ventilation plates are made - as in the 1 and 2 is shown - from a stator 11 , on which distance bars 12 are attached. Through the distance bridge gap 15 a cooling medium, for example air, is guided, which is the stator 10 ' cools.

The stator 10 ' Warms up irregularly over the entire (radial) length of the stator 11 , in the between the winding grooves 14 located teeth 13 more than on the back 13 ' , It is therefore desirable to improve the stator cooling that the air resistance in such "hat spots" is increased to locally get a better heat dissipation.

In the publication EP-B1-0 893 871 It has already been proposed to produce a locally increased air turbulence in order to improve the local heat transfer by means of stamped lobes in the stator lamination. However, such a change to the stator laminations themselves requires complex additional punching processes. In addition, areas of low flow velocity are formed by the stamped lobes, in which particles in the cooling medium can easily deposit and impede the cooling flow.

On the other hand, it is known to use spacer webs which extend in the radial direction between the winding grooves, but are curved towards the back of the stator core in the stator plate plane ( EP-A1-0 039 049 ). A change in the cooling medium flow in the teeth is not connected.

Finally, special embodiments of the spacer webs are known ( WO-A1-2004 / 027960 ), in which a curvature is present in order to direct the cooling medium in targeted areas of the winding (between two winding bars). However, this branched stream is then missing for cooling the tooth area.

PRESENTATION OF THE INVENTION

It Object of the invention, a cooled stator for to create an electric machine, in a simple way the heat generated in the teeth of the stator core is dissipated particularly effective.

The The object is solved by the totality of the features of claim 1. Essential to the invention is that in the interstices in the field of teeth means of local increase the heat transfer between the cooling medium and stator are provided, and that as a means of local increase the heat transfer to the formation of the interstices Serving distance bridges themselves be used. This can in a particularly simple and effective way when installing the necessary Spacers without additional heat transfer be directly improved in the tooth area by the spacer bars be trained accordingly.

According to An embodiment of the invention, the spacer bars at least in the field of teeth deviates from the rectilinear shape embodiment on.

Especially The spacer bars can do this in the area of the teeth be formed zigzag.

It is also conceivable and effective if the spacer bars in the Region of the teeth are wave-shaped.

Farther It is possible that the spacer bars in the area of the teeth are formed meandering.

According to In another embodiment, the spacer bars are in the area of Teeth one or two sides with side mounted on the webs swirling elements provided, wherein the swirling preferably two-sided are mounted on the gap at the spacer bars.

Especially can thereby the swirling elements laterally from the Stand off spacer bars.

According to another embodiment of the invention is that of the rectilinear Shape deviating configuration of the spacer webs on the area limited to the teeth.

But it is also possible that the spacer webs in the teeth in Verwirbelungselemen in the form of baffles.

A Another embodiment of the invention is characterized in that the spacer bars in the teeth a curvature have, or that the spacer bars in the area of the teeth tilted out of the radial direction by a predetermined angle are.

BRIEF EXPLANATION OF THE FIGURES

The Invention will be described below with reference to embodiments explained in more detail in connection with the drawing become. Show it

1 Seen in the axial direction, a stator with radial spacer bars according to the prior art;

2 Seen in the radial direction according to the distance webs 1 clamped gap for cooling the stator core;

3 in one too 1 Comparative illustration of three embodiments of spacer bars according to the invention;

4 in one too 3 comparable representation of three further embodiments of spacer bars according to the invention; and

5 in one too 3 Comparative illustration of two further embodiments of spacer bars according to the invention.

WAYS TO EXECUTE THE INVENTION

In 3 are shown in a representation side by side three different embodiments of the inventive influence of cooling in the tooth region of the stator laminations of an electric machine by a special design of the spacer bars used. The starting point is again a stator plate 11 , Distributed on the inner circumference arranged evenly spaced teeth 13 between which winding grooves 14 are formed.

In the first embodiment, which is designated A, the spacer webs extend 16 in the radial direction continuously from the outer edge of the stator plate 11 to the teeth 13 into the inner edge of the stator lamination 11 , The distance bridges 16 are uniformly zigzag-shaped with equal long straight sections, which are oriented alternately in two different directions. As a result, the radial flow is disturbed, in particular in the tooth region, and a turbulence is caused which enhances the heat transfer between the sheet metal or the winding bars and the cooling medium. At the same time results from the zigzag shape of the spacer bars 16 a wider support of the sheets.

In the second embodiment, which is designated B, have the spacer webs 17 the same radial length as in Example A. In contrast to Example A are the spacer webs 17 formed outside the tooth region as straight webs (web section 17a ) and only shortly before entering the dental area ( 13 ) in a wavy shape over (bridge section 17b ), which works without kinks and oscillates with a regular period and amplitude. The influence of the cooling flow through the web section 17b in the field of teeth 13 depends on the period and amplitude of the waveform and can be changed by their choice.

In the third, denoted by C embodiment of 3 are also spacer bridges 18 used outside the teeth 13 a simple straight bridge section 18a which, shortly before entering the tooth area in a meandering web section 18b with a waveform that is composed of piecewise straight web sections, go over. Again, the period and amplitude of the waveform exert an influence on the turbulence and thus on the heat transfer.

Other embodiments, as denoted by the designation D, E and F in 4 are shown, go unchanged from straight spacer bars 19 . 20 . 21 out, to which swirling elements 19a . 20a and 21a be added: In the embodiment D of the 4 become at the (straight) distance webs 19 in the field of teeth 13 laterally alternating and arranged on gap vortex elements 19a attached, which are bent outwards and engage in the cooling flow accordingly. It may vary in the swirling elements 19a to the distance bridges 19 welded sheet metal strips or the like. Act. In the embodiment E of 4 are in place of the swirled outward swirl elements 19a simple small blocks as turbulence elements 20a used. In the embodiment F of 4 Finally, the straight spacer bars already end in front of the tooth area and are replaced by small baffles, which serve as swirling elements 21a are arranged in an alternating manner obliquely to the flow direction in the flow direction one behind the other. The baffles or turbulators 21a In this case, in order to be able to absorb the stator pressure adequately, they can be connected to one another via strips which, however, are connected in 4 are not shown.

Still other embodiments are known from 5 can be seen and denoted by G and H. In the embodiment G, the Dis run dancing webs 22 oblique to the radial direction and point in the area of the teeth 13 a curvature 22a on, which changes the flow of the cooling medium and thus the heat transfer in the tooth area. In the embodiment H straight spacer bars are in itself 23 used, however, which are arranged tilted by an angle w from the radial direction and in the teeth 13 accordingly oblique. This configuration is particularly easy to implement because the spacer bars themselves do not need to be changed, but only their mounting direction.

All in all results with the invention a simple and effective improvement the cooling in the area of the stator teeth, which with Advantage used in large, refrigerated electrical machines can be.

10 10 '

stator (electric machine)

11

stator lamination

12

distance web

13

tooth (Stator core)

13 '

move (Stator core)

14

winding groove

15

gap (Coolant channel)

16, .., 23

distance web

17a, b

web section

18a, b

web section

19a, 20a, 21a

swirling

22a

curvature

w

angle

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0899856 A2 [0002]
• - EP 0893871 B1 [0004]
• EP 0039049 A1 [0005]
• WO 2004/027960 A1 [0006]

Claims (13)

Stator ( 10 ) for an electric machine, which stator ( 10 ) distributed on the inner circumference by teeth ( 13 ) separate radial winding grooves ( 14 ) and a plurality of stacked in the axial direction of the machine stator plates ( 11 ), between which at certain intervals by inserting in each case in a plane perpendicular to the machine axis and extending substantially in the radial direction spacer webs ( 16 .., 23 ) Spaces ( 15 ) for passing a cooling medium, in particular cooling air, are formed, wherein in the spaces ( 15 ) in the area of the teeth ( 13 ) Medium ( 17b . 18b . 19a . 20a . 21a ) for locally increasing the heat transfer between cooling medium and stator ( 10 ) are provided, characterized in that as means for locally increasing the heat transfer, the spacer webs ( 16 .., 23 ) yourself. Stator according to claim 1, characterized in that the spacer webs ( 16 . 17 . 18 . 22 ) at least in the area of the teeth ( 13 ) have a different design from the rectilinear shape. Stator according to claim 2, characterized in that the spacer webs ( 16 ) in the area of the teeth ( 13 ) are formed zigzag. Stator according to claim 2, characterized in that the spacer webs ( 17 ) in the area of the teeth ( 13 ) wavy ( 17b ) are formed. Stator according to claim 2, characterized in that the spacer webs ( 18 ) in the area of the teeth ( 13 ) meandering ( 18b ) are formed. Stator according to claim 2, characterized in that the spacer webs ( 20 . 21 ) in the area of the teeth ( 13 ) on one or two sides with swirling elements attached laterally to the webs ( 19a . 20a ) are provided. Stator according to claim 6, characterized in that the swirling elements ( 19a . 20a ) on two sides to gap at the spacer webs ( 19 . 20 ) are mounted. Stator according to claim 6 or 7, characterized in that the swirling elements ( 19a . 20a ) laterally from the spacer webs ( 19 . 20 ) stand out. Stator according to one of claims 2 to 8, characterized in that the deviating from the rectilinear configuration of the spacer webs ( 16 . 17 . 18 . 22 ) on the area of the teeth ( 13 ) is limited. Stator according to claim 2, characterized in that the spacer webs ( 21 ) in the area of the teeth in swirling elements ( 21a ) in the form of baffles. Stator according to claim 2, characterized in that the spacer webs ( 22 ) in the area of the teeth a curvature ( 22a ) exhibit. Stator according to claim 2, characterized in that the spacer webs ( 23 ) are tilted in the region of the teeth out of the radial direction by a predetermined angle (w). Electric machine, in particular a generator or motor, with a rotor and a rotor concentrically surrounding the cooled stator ( 10 ), characterized in that the stator is designed according to one of claims 1 to 12.