WO2013110648A2

WO2013110648A2 - Rotating electric machine

Info

Publication number: WO2013110648A2
Application number: PCT/EP2013/051225
Authority: WO
Inventors: Michael Bulatow; Knut Welke; Dirk WESCHE
Original assignee: Continental Automotive Gmbh
Priority date: 2012-01-26
Filing date: 2013-01-23
Publication date: 2013-08-01
Also published as: WO2013110648A3

Abstract

The invention relates to a rotating electric machine (100) comprising the following elements: a housing part (6) with an opening (9), a rotor (1) with a rotor sheet stack (3) arranged in an inner part of the housing (5) of the electric machine (100) and mounted on a rotor shaft (2) which extends out from the housing part (6) through the opening (9); a plurality of slip rings (7) mounted on the rotor shaft (2), outside the housing of the inner chamber (5); a blade wheel (10) which is mounted on the rotor shaft (2) and rotationally fixed thereto, arranged outside of the inner part of the housing (5) between the inner part of the housing (5) and the slip rings (7), which is used to generate an air flow for guiding the dust away from the opening (9) and the slip rings (7).

Description

description

Rotating electrical machine

The present invention relates to a rotary electric machine, in particular an electric motor or a generator. It further relates to a motor vehicle with such a rotating electrical machine.

In modern motor vehicles are increasingly installed electric motors. They are used in particular as drive trains fully integrated in the drive train or in hybrid applications, for example as starter generators. In some cases, externally excited synchronous machines are used which have a rotor made of a laminated core provided with a field winding. The ends of the excitation winding via two slip rings, which are arranged on the rotor shaft, led out. The excitation voltage is applied to the excitation winding via carbon brushes. The two slip rings together with the basic body carrying them are often simply called "slip rings".

In such rotary electric machines, the problem arises that the abrasion of the brush penetrates into the engine interior. This dust of electrically conductive particles can settle, for example as a conductive layer on machine elements and lead to electrically conductive creepage distances.

DE 10014310 AI discloses a floating gap seal for sealing the housing interior. Although such a seal may make it difficult to penetrate dust in the housing interior, there is a need to protect the housing interior even better against the ingress of brush dust. The object of the invention is therefore to provide a rotating electrical machine in which the penetration of brush dust into the housing interior is prevented as much as possible in a technically simple and at the same time particularly effective manner.

According to one aspect of the invention, there is provided a rotary electric machine comprising:

a housing part with an opening,

a rotor having a rotor core arranged in a housing interior of the electric machine and on a rotor shaft guided out through the opening out of the housing part;

a number of slip rings arranged outside the housing interior on the rotor shaft;

- Between the housing interior and the slip rings outside of the housing interior space on the rotor shaft rotatably connected to the rotor shaft paddle wheel is arranged, which serves to generate an air flow for the removal of dust from the opening and / or the slip rings.

Here, a paddle wheel is understood here and below to mean a device which rotates with the rotor shaft and has blades or other flow guide elements in order to generate an air flow during operation. The impeller is outside the housing interior and thus on the side facing the slip rings of housing parts which delimit the housing interior and on which the rotor shaft can be mounted, arranged. It can be arranged, for example, in the brush compartment.

In such a rotating electric machine, the penetration of accumulating brush dust into the engine interior be prevented by the fact that the dust is carried away by an air flow generated by the paddle wheel. For this purpose, the impeller is designed and arranged such that dust accumulating on the brushes is carried away, for example, substantially radially from the rotor shaft to the outside by the airflow generated during operation, or that an air flow is generated from the opening through which the rotor shaft emerges Housing interior is led out, is directed away.

In this embodiment, dust particles are substantially removed before they can penetrate into the housing interior. By means of the co-rotating paddle wheel, an air flow is relatively easy to produce.

The air flow generated by the impeller may also contribute to the cooling of elements outside the housing interior and possibly of the housing interior bounding housing parts, because it causes a temperature compensation.

In one embodiment, at least one labyrinth seal is provided between the housing interior and the slip rings.

Under a labyrinth seal is here and below understood a non-contact seal whose sealing effect is based on the significant extension of the path through the labyrinth. The path extension can be achieved by a meshing of form elements on the rotor shaft and a fixed housing part.

In such a rotating electric machine, the penetration of accumulating brush dust into the engine interior can be prevented by the distance traveled by the dust way up into the housing interior and significantly extended Labyrinthwindungen is provided, which prevents unimpeded penetration of dust through the opening.

The labyrinth seal may in particular be designed as a multi-groove labyrinth seal and have a plurality of series-connected in series sealing elements of intermeshing mold elements.

In one embodiment, the labyrinth seal is formed from molded elements on the rotor shaft and with these combing mold elements on a housing part, wherein the mold elements have a surface made of an electrically insulating material, for example plastic. The mold elements may also be formed entirely from plastic.

The housing part typically has an opening for the passage of the rotor shaft. In this opening, the

Labyrinth seal be arranged concentrically around the rotor shaft around.

The provision of a labyrinth seal additionally increases the sealing effect and thus advantageously complements the effect of the paddle wheel.

In this case, the impeller and / or the labyrinth seal can be arranged within a brush space which surrounds the rotor shaft in the region of the slip rings and brushes.

In one embodiment, the paddle wheel is the

Labyrinth seal upstream dust flow side. In this embodiment, coming from the slip rings dust flow thus enters first in the sphere of action of the paddle wheel, which is a large part of the dust particles from the critical area away. Only a very dense dust flow thus still hits the labyrinth seal.

In an alternative embodiment, the impeller of the labyrinth seal downstream of the dust flow side. It can also be provided several paddle wheels and / or labyrinth seals.

If the slip rings are designed as dry-running slip rings, the use of the paddle wheel and possibly also of the labyrinth seal is particularly advantageous.

In one embodiment, the impeller is attachable to the rotor shaft. In this embodiment, the impeller can be easily attached to the rotor shaft during assembly, so that little additional installation effort is necessary.

In one embodiment, the rotating electric machine is designed as an electric motor. It can also be designed as a generator or be operable both as a motor and as a generator.

Such rotating electrical machines are suitable for use in a motor vehicle. They can be used both as drive in the drive fully integrated drive motors, for example as wheel or axle motors, as well as, for example, as a starter generators. According to one aspect of the invention, therefore, there is provided a motor vehicle having the described rotary electric machine. The motor vehicle can be designed as an electric or hybrid vehicle.

Embodiments of the invention will now be described in more detail with reference to the accompanying figures. Figure 1 shows schematically a rotor for a rotary electric machine according to a first embodiment of the invention and Figure 2 shows schematically a rotor for a rotary electric machine according to a second embodiment of the invention.

Identical parts are provided in both figures with the same reference numerals.

FIG. 1 shows a rotor 1 for an electric machine 100, which is designed as a separately excited synchronous machine. The stator of the electric machine 100 is not shown. The rotor 1 comprises a rotor laminated core 3 arranged on a rotor shaft 2.

The rotor core 3 is arranged in a housing interior 5. The rotor shaft 2 is rotatably mounted in the housing interior 5, wherein only one bearing 4 is shown. The rotor shaft 2 is led out of the housing interior 5 through an opening 9 in a housing part 6, for example a bearing plate.

Outside the housing interior 5, two slip rings 7 are arranged on the rotor shaft 2, via which the exciter voltage is applied to the excitation windings of the rotor 1, not shown, by means of carbon brushes 8.

A slip ring capsule, not shown, can surround the slip rings 7 and the carbon brushes 8 and thus the brush space 12.

During operation of the rotor 1, electrically conductive carbon dust is generated by the carbon brushes 8 in the brush chamber 12. Through the opening 9, for example, the coal dust in the housing Se interior 5 penetrate there settle as an electrically conductive layer and lead to leakage currents.

To prevent this, the rotor 1 has a paddle wheel 10 in the region of the opening 9 on the rotor shaft 2. The paddle wheel 10 is rotatably connected to the rotor shaft 2, so in operation with this rotates. It generates an air flow, which carries away dust particles from the opening 9. In the opening 9 an inlet contour 11 is provided which supports the action of the paddle wheel 10. In particular, the inlet contour 11 can leave a larger diameter at the end of the opening 9 facing the slip rings 7 than at the end facing the housing interior 5 in order to facilitate the venting of carbon dust and to improve the outflow of the air.

FIG. 2 shows the rotor 1 according to a second embodiment. This embodiment differs from the first shown in Figure 1 in that in addition to the paddle wheel 10 is still a labyrinth seal 13 is provided to prevent the ingress of dust into the housing interior 5. In this case, the paddle wheel 10 of the labyrinth seal 13 is upstream of the dust flow side, that is, it is first passed by air flowing in the direction of the housing interior 5.

In one embodiment, not shown, the paddle wheel 10 of the labyrinth seal 13 downstream of the dust flow side. It can also be several paddle wheels 10 and / or

Labyrinth seals 13 may be provided.

The labyrinth seal 13 is formed by a first mold element 14 which is connected to the housing part 6 and arranged in the opening 9, and by a second mold element 15 which is non-rotatably connected to the rotor shaft 2. The mold elements 14, 15 have intermeshing and non-contacting "sealing lips" 16 and are formed from a plastic or from another electrically non-conductive material A path is formed between these sealing lips 16, which, however, is significantly longer than the length the opening 9. The distance to be traveled by the coal dust in the housing interior 5 is thus significantly extended by the labyrinth seal 13, resulting in the sealing effect.

In an embodiment not shown, the

Labyrinth seal on a larger number of successively arranged, intermeshing sealing lips. As a result, the path to be traveled by the coal dust is additionally lengthened and the sealing effect is increased.

Although at least one exemplary embodiment has been shown in the foregoing description, various changes and modifications may be made. The above embodiments are merely examples and are not intended to limit the scope, applicability, or configuration in any way. Rather, the foregoing description provides those skilled in the art with a scheme for practicing at least one example embodiment, and various changes may be made in the operation and arrangement of elements described in an exemplary embodiment without departing from

Scope of the attached claims and their legal equivalents. LIST OF REFERENCE NUMBERS

100 rotating electrical machine

1 rotor

2 rotor shaft

3 rotor core

4 bearings

5 housing interior

6 housing part

7 slip ring

8 carbon brush

9 opening

10 paddle wheel

11 inlet contour

12 brush room

13 labyrinth seal

14 first mold element

15 second mold element

16 sealing lip

Claims

A rotary electric machine (100) comprising:

- A housing part (6) having an opening (9),

- A rotor (1) with a in a housing interior (5) of the electric machine (100) and on a through the opening (9) from the housing part (6) led out rotor shaft (2) arranged rotor core (3);

- A number of outside the housing interior (5) on the rotor shaft (2) arranged slip rings (7);

- Between the housing interior (5) and the slip rings (7) outside of the housing interior (5) on the rotor shaft (2) with the rotor shaft (2) rotatably connected paddle wheel (10) arranged to generate an air flow for removing dust from the opening (9) and / or the slip rings (7).

A rotary electric machine (100) according to claim 1, wherein between the housing interior (5) and the

Slip rings (7) at least one labyrinth seal (13) is provided.

A rotary electric machine (100) according to claim 1 or

2, wherein the paddle wheel (10) and / or the

Labyrinth seal (13) within a brush space (12) are arranged.

A rotary electric machine (100) according to claim 2 or

3, wherein the paddle wheel (10) of the labyrinth seal (13) upstream of the dust flow side.

5. Rotary electric machine (100) according to claim 2 or 3, wherein the paddle wheel (10) of the labyrinth seal (13) downstream of the dust flow side.

6. Rotary electric machine (100) according to one of

Claims 3 to 5, wherein the labyrinth seal (13) is designed as a multi-groove labyrinth seal.

7. Rotary electric machine (100) according to one of

Claims 2 to 6, wherein the labyrinth seal (13) of the form elements (15) on the rotor shaft (2) and with these combing mold elements (14) on a housing part (6) is formed, wherein the mold elements (14, 15) has a surface an electrically insulating material.

8. Rotary electric machine (100) according to one of

Claims 1 to 7, wherein the paddle wheel (10) on the rotor shaft (2) can be plugged.

9. Rotary electric machine (100) according to one of

Claims 1 to 7, which is designed as an electric motor.

10. Motor vehicle with a rotating electrical machine (100) according to one of claims 1 to 9.