WO2010069644A1

WO2010069644A1 - Commutator for an electric machine and the electric machine

Info

Publication number: WO2010069644A1
Application number: PCT/EP2009/063744
Authority: WO
Inventors: Roland Oesterlein; Heiko Sponar; Juergen Tempel; Maxim Sukhman
Original assignee: Robert Bosch Gmbh
Priority date: 2008-12-17
Filing date: 2009-10-20
Publication date: 2010-06-24
Also published as: DE102008054791A1

Abstract

The invention relates to a commutator (1) for an electric machine, having multiple commutator segments (3), each of which has a holding element (9) for a winding wire (13) of a rotor winding on an extended segment end (6). It is provided that the segment end (6) as the holding element (9) has a substanitally fork-shaped winding wire receptacle (10). The invention also relates to an electric machine having a rotor, which has at least one rotor winding comprising multiple winding wires (13), wherein at least one winding wire (13) is held on a holding element (9) of an extended segment end (6) of a commutator segment (3) of a commutator (1).

Description

description

title

Commutator for an electric machine and electric machine

The invention relates to a commutator for an electric machine, with a plurality of commutator fins, each having at a prolonged fin end a holding element for a winding wire of a rotor winding.

Furthermore, the invention relates to an electrical machine having a rotor, which has at least one rotor winding comprising a plurality of winding wires, wherein at least one winding wire is held on a holding element of an extended fin end of a commutator lamination of a commutator.

State of the art

Commutators of the type mentioned are known. Commutators serve to reverse the direction of current of DC electric machines. The commutator has arranged on a support member commutator fins, which cooperate with carbon brushes and are each electrically and mechanically connected to a winding wire of a rotor winding of the electric machine. The winding wires of the rotor winding are thus supplied with current via the carbon brushes and the commutator. The attachment of the winding wires to the commutator or to the respective commutator lamella is of particular importance in this case, since an electric motor is used

Permanent connection must be ensured even under high loads. For this purpose, different solutions have already been developed. Such a solution is also the so-called hook commutator, in which the commutator slats have an extended fin end, so are formed extended over the normal range of use of the commutator, and at this fin end a holding element in the form of a hook, the is formed by the corresponding bent fin end itself. This allows a simple and inexpensive connection of the winding wires to the commutator. However, in order to be able to be attached to the hook, the winding wires must have a loop geometry, with the result that the spacing between the adjacent loop geometries or winding wires is very small. The loops of the winding wires are substantially tangential to the commutator. In order to ensure a permanent electrical contact between the winding wire and the corresponding commutator lamella, a contacting process is usually carried out in which, for example, the winding wire is connected by means of resistance welding to the commutator lamella materially. However, the smaller the distances between the loop geometries, the higher the risk of a short circuit due to the contacting process. As a result, the number of commutator fins and thus ultimately the power of the electric machine is limited for a given installation space.

Disclosure of the invention

Due to the advantageous embodiment of the commutator according to the invention these problems are avoided. For this purpose, the invention provides that the fin end has a substantially fork-shaped winding wire receptacle as a holding element. It is therefore provided that the extended lamellar end has a winding wire receptacle which is fork-shaped. Wherein under the fork-shaped training two substantially parallel and spaced from each other extending legs of the fin end are to be understood. The intermediate space located between the legs forms a receptacle, namely the winding wire receptacle. In contrast to the hook-commutator solution of the prior art, the winding wire does not have to be looped around the holding element. Instead, as described above, the holding element is designed such that it receives the winding wire or, advantageously, a winding wire end. Due to the fork-shaped design of the extended fin end of such a disadvantageous space-demanding geometry of the winding wire is not necessary. Conveniently, the winding wire receiving radially and / or axially aligned. This means that the winding wire receptacle or ultimately the legs forming the fork shape extend in the longitudinal direction of the fin end, that is to say essentially axially to the commutator. The orientation of the winding wire receptacle allows correspondingly a radial and / or axial insertion (with respect to the commutator) of a winding wire, in contrast to a substantially tangential looping of the retaining element according to the prior art. The advantageous winding wire recording thus allows for a constant space a higher number of commutator fins and thus winding wires, which allows implementation of previously impossible magnetic circuit or motor designs, especially in connection with electrical machines having a high number of pole pairs. The bifurcated design of the winding wire receptacle results in an advantageous U-shape for receiving a winding wire or a winding wire end.

According to a development of the invention, the winding wire receptacle is formed at least partially elastically deformable. This has the advantage that a winding wire can be clamped in the assembly of the electrical machine in the winding wire receiving, whereby the winding wire remains safe in its desired position after the winding process and a subsequent contacting process for establishing the permanent electrical and mechanical connection can be easily performed without an additional holding the winding wire in the winding wire recording is needed. In addition, by the elastic deformation manufacturing and assembly tolerances can be compensated in a simple manner.

Advantageously, the winding wire receptacle is formed as an edge-open recess produced by milling and / or punching out in the fin end.

According to an advantageous development, the winding wire receptacle is designed as a receiving pocket. Advantageously, the receiving pocket is essentially formed by two opposite bent side edges of the blade end. In this case, it is provided that by forming or bending the fin end the fork-shaped winding wire Recording is formed. The main difference of the receiving pocket to the open-edged recess is that now a longer portion of a winding wire end can be held by the winding wire receiving. On the one hand, this leads to increased mechanical safety and to an increased contact surface between the corresponding commutator

Slat and the winding wire. Also, the rigidity of the fin end is increased because the bent side edges act like stiffening ribs. In addition, the winding wire receptacle produced by deformation of the fin end allows a particularly simple and cost-effective production of the commutator blades, in particular simple flat parts.

Furthermore, it is provided that the lamella has a bilateral taper in the boundary region to the extended lamella end. There is thus a narrowing or a constriction between the main part of the commutator lamella and the fin end, so that the lamella is narrower in the border area than the rest of the commutator lamella. The side edges of the fin end, insofar as they are wider than the taper, thereby bendable in a simple manner for forming the receiving pocket. In this case, the side edges of the fin end are expediently bent over their entire longitudinal extent. The taper can be made in a simple manner by punching and / or milling.

According to a preferred development of the invention, the commutator lamella is bent over in the boundary region in such a way that the lamella end is oriented substantially radially, in particular outward-pointing. The fin end is thus substantially perpendicular to the rest of the commutator lamella. Of course, any other (angular) alignment of the fin end is conceivable. Since commutator lamellae generally have a curvature when viewed in cross-section, the taper promotes the bending of the fin end.

Finally, it is provided that the winding wire receptacle is designed to receive one or more winding wire ends. The winding wire receptacle is expediently designed to be correspondingly wide and / or deep. The electric machine according to the invention is characterized by the design of the commutator as described above. This results in the abovementioned advantages, in particular a higher number of commutator lamellae.

For this purpose, the respective winding wire advantageously lies with its winding wire end in the winding wire receptacle and / or is clamped in the winding wire receptacle. The pinching can be realized in different ways. On the one hand by the above-described, at least partially elastic deformability of the winding wire receptacle or the corresponding leg, on the other hand, the winding wire end in the winding wire recording by subsequent deformation of the winding wire recording, in particular by embossing and / or pressing, are attached.

Particularly preferably, the respective winding wire end is electrically and mechanically connected to the corresponding winding wire receptacle by means of a material bond. The material bond is advantageously produced / produced by means of a contactless contacting process. As a corresponding method, for example, a fusion welding method such as laser welding (micro) flame welding, (micro) plasma welding, electron beam welding, and / or any other suitable non-contact welding method may be used. Of course, however, any contacting method, such as, for example, the so-called hot-staking method, resistance welding or also soldering, can be considered as the contacting method. The advantageous embodiment of the winding wire receiving allows the preferred non-contact contacting method, which results in significant process time advantages and thereby cost savings, since electrical contacts can be generated by the non-contact method compared to touching method in a very short time.

In the following, the invention will be explained in more detail with reference to several embodiments. Show this

1 shows a first embodiment of an advantageous commutator in a perspective view, FIG. 2 shows the commutator in a top view,

FIG. 3 shows an enlarged representation of a winding wire receptacle of the commutator,

4 shows a second embodiment of the advantageous commutator in a perspective view,

Figure 5 shows a third embodiment of the advantageous commutator in a perspective view and

Figure 6 shows a fourth embodiment of the advantageous commutator in a perspective view.

1 shows a perspective view of a first embodiment of an advantageous commutator 1, which has a plurality of arranged on the lateral surface of a substantially cylindrical support member 2 commutator fins 3. For reasons of clarity, only some of the commutator lamellae 3 are provided with reference numerals here. The commutator

Slats 3 extend in the axial direction over the entire length of the carrier element 2. At a first end face 4 of the carrier element 2, they are flush with it. On the end face 4 opposite end face 5 of the support member 2, the commutator slats 3 each have an extended fin end 6, which extends beyond the support member 2 addition. The lamella ends 6 are oriented substantially radially outward. For this purpose, each commutator lamella 3 in its boundary region 7 or transition to the extended lamella end 6 on both sides of a taper 8, which allows easy bending of the commutator lamella 3 in the boundary region 7.

Each of the commutator lamellae 3 has at its lamella end 6 as a holding element 9 a substantially fork-shaped winding wire receptacle 10. In the present exemplary embodiment, the winding wire receptacle 10 is formed in each case by two legs extending essentially parallel to each other, so that the winding wire receptacle 10 has a U-shape. in this connection arises a fork of the fin end 6 in the direction of its longitudinal extent, wherein the winding wire receiving 10 of the present embodiment is radially aligned. The winding wire receptacle 10 is presently designed as open-edged recess 1 1 in the fin end 6. A winding wire of a rotor winding of an electric machine having the commutator 1 can now be inserted in a simple manner into one of the winding wire receptacles 10 with its winding wire end. A space-consuming looping like a hook commutator is eliminated. The winding wire end is initially held substantially positively in the winding wire receptacle 10 because of its advantageous embodiment.

In a subsequent contacting process, the winding wire end is advantageously determined by means of a non-contact method finally at the corresponding blade end 6 in the respective winding wire receptacle 10. Since the winding wire with its winding wire end can be easily inserted into the winding wire receptacle 10, without a special loop-shaped deformation of the winding wire end must take place, which would increase the risk of short circuit with an adjacent winding wire, it is possible with the advantageous commutator 1 at the same space, a higher number of commutator lamellae 3 vorzusehen.

2 shows the commutator 1 in a plan view of the end face 4. Due to the advantageous orientation of the blade ends 6 radially outward, the winding wire receptacles 10 are on a larger radius or diameter than the commutator blades 3 itself

Installation of an electrical machine with the commutator 1 much easier because there is more space available in the area of the winding wire receptacles 10. In the plan view, the fork-shaped design of the winding wire receptacle 10 or of the holding element 9 can be seen particularly well.

FIG. 3 shows, in an enlarged detail from FIG. 2, one of the winding wire receptacles 10 in which a winding wire end 12 of a winding wire 13 of the rotor winding of an electrical machine rests. In this case, the diameter of the winding wire end 12 is advantageously made larger than the winding wire receptacle 10 is wide, so that the winding wire end 12 is held in the winding wire receptacle 10 by means of a press fit is. Conveniently, the winding wire end 12 and / or the winding wire receptacle 10 is elastically and / or plastically deformed. In the assembly of the electrical machine thereby pinching of the winding wire end 12 in the respective winding wire receptacle 10 is possible, whereby the winding wire end 12 is held in a form-locking and force-locking manner in the winding wire receptacle 10 even before a final contacting process. In addition or as an alternative, the winding wire end 12 in the winding wire receptacle 10 is fixed by means of subsequent clamping or embossing, that is to say by subsequent deformation of the fin end 6 in the region of the winding wire receptacle 10, as indicated by arrows. As a final contacting process, methods known to those skilled in the art can be used. Advantageously, contacting methods which can be carried out without contact, such as, for example, fusion welding methods, such as laser welding (for example with solid-state, gas, semiconductor or fiber lasers), (micro) flame welding (for example by combustion of a stoichiometric oxygen and hydrogen mixture), To use (micro) plasma welding, electron beam welding and / or any other suitable non-contact welding process. Alternatively, established contacting methods, such as hot staking, resistance welding or brazing as a contacting method into consideration. The advantageous embodiment of the commutator 1 allows easy access to the winding wire end 12, so that the currently selected contacting method is easy to carry out. Particularly preferably, the winding wire receptacle 10 is designed such that a plurality of winding wire ends (12) can be received by it.

In FIG. 4, the commutator 1 is shown in perspective in a second exemplary embodiment. Identical parts are provided with the same reference numerals, so that reference is essentially made to the description of the preceding figures and here only the differences are explained. In contrast to the previous exemplary embodiment, the commutator lamellae 3 now have no taper 8 and a flat lamella end 6. Of course, the other, in particular the embodiments described above without the taper 8 may be formed. Otherwise, the winding wire receptacle 10 corresponds to the previous exemplary embodiment. Due to the flat design of the commutator blade or the fin end 6, so by the axial orientation of the blade lenendes 6, the winding wire receptacle 10 is axially aligned. Since the lamella ends 6 extend beyond the end face 5 of the carrier element 2, there is a free space on the inner side of the lamella ends 6 through which a winding wire end can pass or into which a winding wire end can protrude. During assembly, the winding wire end 12, for example, as shown in Figure 4, placed over the recess 1 1 of the winding wire receptacle 10 and optionally then partially introduced by means of a corresponding tool in the winding wire receptacle 10. Also in this embodiment, the commutator 1 allows easy assembly and a high number of commutator fins third

5 shows a third exemplary embodiment of the commutator 1 in a perspective view. Again, the same elements are provided with the same reference numerals, so that only the differences should be discussed. Essentially, the present embodiment differs from the first embodiment in that the winding wire receptacles 10 are not formed as recesses 1 1, but as receiving pockets 15. For this purpose, the lamella ends 6 each have two oppositely bent side edges 16, which ultimately form the legs of the fork-shaped winding wire receptacle 10. The winding wire shots

10 of the third embodiment are thus again substantially radially aligned, wherein a winding wire end can be inserted into the receiving pockets 15 after the winding process in a simple manner by it is bent into the receiving pocket 15 so that it is substantially perpendicular to the support element 2 shows. Due to the advantageous embodiment of the receiving pockets 15, a larger contact area between the respective winding wire end 12 and the corresponding winding wire receptacle 10 is ensured in comparison with the preceding embodiments.

FIG. 6 shows a perspective illustration of a fourth exemplary embodiment of the advantageous commutator 1, which substantially corresponds to a combination of the first and the third embodiment. The same elements are provided with the same reference numerals. In contrast to the third embodiment, the lamella ends 6 next to the

Receiving pocket 15 on the front side an open-edged recess 17 which in the We- sentlichen the recess 11 corresponds. As a result, an even greater hold on the commutator 1 after the winding process and before the contacting process is provided for a winding wire end. During assembly, for example, the winding wire end can now first be inserted axially into the recess 17 and then bent into the receiving pocket 15. The winding wire is thereby held after the winding process in the winding wire receiving 10, so that the subsequent contacting process is easy to carry out. In addition, it is conceivable to form the receiving pockets 15 such that they are at least partially elastic, so that one (or more) winding wire end (s) 12 can be clamped in this (are). Even with the receiving pockets 15 is a subsequent pressing / embossing of the winding wire ends after insertion is conceivable.

Claims

claims

1. commutator (1) for an electrical machine, with a plurality of commutator lamellae (3), each having at a prolonged fin end (6) a holding element (9) for a winding wire (13) of a rotor winding, characterized in that the fin end (6) as a holding element (9) has a substantially fork-shaped winding wire receptacle (10).

2. Commutator according to claim 1, characterized in that the winding wire receptacle (10) is radially and / or axially aligned.

3. Commutator according to one of the preceding claims, characterized in that the winding wire receptacle (10) is formed at least partially elastically deformable.

4. Commutator according to one of the preceding claims, characterized in that the winding wire receptacle (10) is designed as an open-edged recess (1 1) in the fin end (6).

5. Commutator according to one of the preceding claims, characterized in that the winding wire receptacle (10) is designed as a receiving pocket (15).

6. Commutator according to one of the preceding claims, characterized in that the receiving pocket (15) is essentially formed by two oppositely bent side edges (16) of the fin end (6).

7. Commutator according to one of the preceding claims, characterized in that the lamella (3) in the boundary region (7) to the extended fin end (6) has a two-sided taper (8).

8. Commutator according to one of the preceding claims, characterized in that the commutator blade (3) in the boundary region (7) is bent such that the fin end (6) is oriented substantially radially, in particular outwardly facing.

9. Commutator according to one of the preceding claims, characterized in that the winding wire receptacle (10) for receiving one or more winding wire ends (12) is formed.

10. Electrical machine with a rotor having at least one winding winding comprising a plurality of winding wires, wherein at least one winding wire (13) on a holding element (9) of an extended fin end (6) of a commutator blade (3) of a commutator (1) held characterized by the formation of the commutator (1) according to one or more of the preceding claims.

1 1. Electrical machine according to claim 10, characterized in that the winding wire (13) rests in the winding wire receptacle (10) and / or is clamped.

12. Electrical machine according to one of the preceding claims, characterized in that the winding wire (13) with the winding wire recording (10) by means of a material connection is electrically and mechanically connected.