DE2312646A1 - DRUM-SHAPED COMMUTATOR FOR ROTATING ELECTRICAL MACHINERY AND THE PROCESS FOR THE PRODUCTION THEREOF - Google Patents

Description

28 * 2.1973 Sa / Sz

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ROBERT BOSCH GMBH, Stuttgart

Drum-shaped commutator for rotating electrical machines and process for their production

The invention relates to a drum-shaped commutator for rotating electrical machines with an insulating hub anchored lamellas, the connection-side end section of which has hooks for hanging and contacting winding ends of the machine runner is provided.

With commutators of this type, it is customary to use the relevant winding end to be connected to the hook assigned to it by welding (hot staking) after it has been hooked into the hook. To do this, a Electrode placed on the free end of the hook and the in

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This hanging winding end is welded to the hook by means of electrical heat. The end of the winding hanging in the hook loses it on both sides of the hook its isolation over a certain area, so that, to avoid touching two uninsulated, each other To avoid adjacent winding ends, a certain safety distance between these ends must not be undershot allowed. This safety distance is determined by the hook distance, which in turn is determined by the collector diameter and the The number of lamellas is specified within certain limits. The wire diameter also plays a role in determining the safety distance the winding ends to be contacted play a role.

In order to keep this safety distance as large as possible, one has in a known commutator made of individual lamellas, each lamella near its facing away from the lamellar track End set by 90 ° and the connecting hook molded onto it. As a result, the hook spacing was significantly increased, so that the hook width now only corresponded to the lamellar sheet thickness. However, the hot staking welding process requires a certain one Coordination between wire diameter and hook width, so that the known collector lamellae are used for welding thicker wires would also have to be manufactured from thicker sheets, but this is not economical.

The invention is based on the problem of collectors of the type mentioned at the outset in relation to their track diameter large number of lamellas to maintain the so-called safety distance between the adjacent winding ends, when the wire diameter is large. In determining "The thickness of the lamellae should only be made based on the considerations that are common with unrestricted lamellas.

According to the invention this is achieved in that the collector lamellae diverge from the raceway for the carbon brushes to the contact hooks.

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By this measure, the hook spacing and thus also the Safety distance can be adapted to the circumstances without difficulty, so that that occurs in the hot-staking welding process Burning off the wire insulation has no adverse consequences, such as B. short circuit in the machine rotor has. It is also the case when certain minimum distances between hooks are not exceeded It is possible to attach the winding ends to the connection hook by machine.

With such a commutator, the diameter in the area of the contact hook is advantageously greater than in the area of the track for the carbon brushes.

So that the commutator retains a compact design, the increase in diameter can advantageously be achieved by that the lamellae are stepped down in the direction of the contact hook.

To ensure that the individual lamellas are well anchored in a commutator hub ensure, according to the invention, it is also advantageous to use V7 € mn on the surfaces facing away from the connecting hooks The lamellas are provided with holding claws machined from the lamellar sheet.

In a further development of the inventive concept, an advantageous one Process for the production of the commutators according to the invention seen in the fact that a pipe section at its one with the Contact hook widened to the end to be provided, equipped on its inner wall with the retaining claws and with a plastic hub and that the pipe section is then split in its axial direction into the required number of lamellas, the contact hooks are formed and at least the track for the carbon brushes is post-treated.

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A convenient manufacturing process for such commutators however, it can also be seen in the fact that a predetermined number of individual lamellas placed in a mold and pressed be held with a plastic hub in their correct position and that the commutator blank thus formed at least is post-treated in the area of the raceway for the carbon brushes.

The invention is explained in more detail below with reference to an embodiment shown in the drawing.

Show it:

Fig. 1 shows a commutator according to the invention in a view, shown enlarged,

FIG. 2 shows a longitudinal section through a commutator according to FIG. 1, where the cut in the upper half is through a lamella and in the lower half between two lamellas has been passed through.

A commutator 10 has a hub 11 made of plastic, and thy circumference a number of copper segments 12 by means of retaining claws 1J _t are anchored 14 and 15 (Fig. 2). Each collector lamella 12 has a running surface 16 extending from its one end for the carbon brushes and at the other end of the lamella 12 a contact hook 17 is bent into which the winding ends 18 (FIG. 2) are hooked and contacted by armature windings. Near the connecting hook 17, each collector lamella 12 has an outwardly directed shoulder 19, to which the contact hook 17 connects, so that the diameter of the commutator 10 in the area of the contact hook 17 is greater than in the area of the track formed by the individual running surfaces 16 for the Carbon brushes. As a result, the distance between the individual contact hooks 17 is greater than between the individual lamellae in the area of their running surfaces 16, so that the safety distance 20 even in the case of collectors with very small diameters and / or a large number of lamellae

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can be maintained between the individual winding ends 18.

In an advantageous method for producing the described Collector, a piece of copper pipe is widened at its one end portion, so that the shoulder 19 is formed. After that will be the retaining claws 13, Ή and 15 worked out of its inner wall, preferably peeled out. The plastic hub 11 is then pressed into this pipe section, with the aid of the retaining claws 13, 14 and 15 pressed together between the two Parts 11 and 12 a secure connection is guaranteed. With With the help of a cutting tool, the pipe is now in the ev / 'orderliche Number of lamellas 12 separated, with the lower cut 21 is guided in the axial direction of the hub 11. The separating cuts 21 are placed so that each collector lamella 12 for itself by retaining claws 13 »14 and 15 is held. Then v / ground to the individual Collector lamellas 12 formed the contact hooks 17 and through the running surfaces 16 of the individual lamellae 12 are post-treated for the carbon brushes.

However, another method for producing the commutators according to the invention is also conceivable. After that there will be a number of pre-formed individual lamellae 12 placed in a mold and pressed with a plastic hub 11 in kept in their proper position. In this case too, the connection between the hat 11 and the collector lamellas 12 caused by the retaining claws 13, 14 and 15 provided on the lamellae 12. The commutator blank coming out of the press mold is then reworked in a further operation in the area of the running surface 16 of the copper lamellae 12, so that a flawless raceway is formed for the carbon brushes of the machine.

409838/0128

BATH ORIGINAL

Claims (6)

- 6 - row 1 3 7 8 Expectations M. Drum-shaped commutator for rotating electrical machinery. NEN, with lamellae anchored in an insulating hub, the connection-side end section of which with hooks for hanging and contacting provided by winding ends of the machine runner is characterized in that the collector lamellas (12) diverge from the raceway for the carbon brushes to the contact hooks (.17). 2. Commutator according to claim 1, characterized in that the diameter of the commutator (10) in the region of the contact hook (17) is larger than in the area of the raceway for the carbon brushes. 3. Commutator according to one of claims 1 or 2, characterized in that that the lamellae (12) are stepped off in the direction of the contact hooks (17). 4-, commutator according to one of claims 1 to 3 »characterized in that that on the surfaces of the lamellae (12) facing away from the connecting hook (17) worked out of the lamellar plate Retaining claws (13 »14 and 15) are provided. 4098 3 8/0128 - 7 - ^Ε 1 3 7 8 5. A method for producing commutators according to one of claims 1 to 4, characterized in that a pipe section is widened at its one end to be provided with the contact hook (17), on its inner wall with the retaining claws (15 »1 ^» 15) and is equipped with a plastic hub (11) and that the pipe section is then separated in its axial direction into the required number of lamellae (12), the contact hooks are formed and at least the raceway for the carbon brushes is post-treated. 6. A method for producing commutators according to one of the Claims 1 to 4, characterized in that one is provided Number of λ ^ οη individual lamellas (12) inserted into a press mold and are held in their correct position by pressing with a plastic hub (11) and that the so formed commutator hollow ring is post-treated at least in the area of the track for the carbon brushes. 409838/0128 Blank page