WO2010009959A2

WO2010009959A2 - Commutator for an electrical machine and system

Info

Publication number: WO2010009959A2
Application number: PCT/EP2009/058270
Authority: WO
Inventors: Daniel Klumpp; Michael Huber
Original assignee: Robert Bosch Gmbh
Priority date: 2008-07-25
Filing date: 2009-07-01
Publication date: 2010-01-28
Also published as: EP2308155A2; DE102008040717A1; WO2010009959A3

Abstract

The invention relates to a commutator (1) for an electrical machine, comprising a plurality of juxtaposed laminations (5) which are separated by respective lamella slots (6) for interaction with wiping contacts and a central passage (3) for sliding the commutator (1) onto an armature shaft of an electric motor. The invention is characterized in that the commutator (1) has a front geometry (10) which is designed to form-lock with a displacement and/or alignment device. The invention further relates to a system.

Description

description

title

Commutator for an electric machine as well as system

State of the art

The invention relates to a commutator according to the preamble of claim 1 and to a system according to claim 8.

From WO 2003075436 Al a commutator for an electric machine is known. In such, also referred to as a commutator or commutator commutator is a device for current application in electrical machines see. The current application generates a current that flows from armature winding to armature winding of a rotor of the electric machine or to change the current in order to generate a torque during a rotational movement of the armature winding. Commutators have a multiplicity of copper lamellae which are arranged next to one another in the circumferential direction and interact with sliding contacts for making electrical contact. Known commutators have a central passage opening, by means of which they can be pushed onto an armature shaft of the electric machine and fixed by pressing seats at this. Both when sawing the individual copper lamellae from each other electrically insulating lamella slots as well as when joining the commutator to the armature shaft, the commutator on the geometry of the circumferentially arranged lamellar slots is oriented (aligned). The position detection takes place optically or mechanically. The known approach to alignment of the commutator results in position inaccuracies between the armature winding slots in the armature package and the commutator of up to about ± 1.5 °. On the one hand, this is due to production inaccuracies of the commutator, in particular to pitch tolerances between the slat slots, as well as to positional tolerances during assembly. If the commutator is pushed further, the radial alignment may additionally deteriorate.

The described position inaccuracies between the commutator and the armature package lead to significant fluctuations in characteristic curve, in particular in the case of high-power electrical machines.

DISCLOSURE OF THE INVENTION Technical Problem

The invention is therefore based on the object to propose a commutator, can be at least largely avoided with the position inaccuracies between the commutator and another element, such as the anchor assembly of an electric machine or a sawing device for producing the Lammellenschlitze. Furthermore, the object is a system for avoiding position inaccuracies between the commutator and another element.

Technical solution

This object is achieved in terms of the commutator with the features of claim 1 and in terms of the system with the features of claim 8. Advantageous further Formations of the invention are specified in the subclaims. All combinations of at least two features disclosed in the description, the claims and / or the figures fall within the scope of the invention.

The invention is based on the idea, in addition to the slat slots provide a reliable and accurate geometry on an end face of the commutator, which is designed for positive cooperation with a displacement and / or alignment. In other words, a commutator designed according to the concept of the invention has a geometry (alignment geometry) on a front side remote from the armature packet, preferably in the mounted state, which is designed for positive connection to a counter-geometry of a displacement and / or alignment device , In this case, the geometry must be designed such that torques acting on it in the circumferential direction, which occur, for example, during the sliding of the commutator, can be supported and / or introduced.

Under a displacement device is a means for axial displacement of the commutator, in particular along the armature shaft of an electric machine in the assembly of an electric machine to understand. By intervening in the geometry of the commutator adapted to the geometry of the commutator counter-geometry in the geometry of the commutator twisting of the commutator can be avoided relative to the displacement device during the displacement process.

An alignment device is to be understood as a device with which the commutator can be pivoted about its longitudinal center axis, in order to thereby move the commutator in the circumferential direction. tion to an element, in particular an anchor assembly of an electrical machine or a saw of a manufacturing device for producing the slat slots to align exactly. Very particular preference is given to an embodiment in which an axial displacement possibility and a pivoting possibility in the circumferential direction are combined in a common displacement and alignment device.

By providing a corresponding end-face geometry for aligning the commutator and for preventing a rotation of the commutator during axial displacement, position inaccuracies can be caused both in the manufacture of the commutator and in the assembly of an electrical commutator

Machine, in particular a motor for parking tasks in motor vehicles, be avoided. Likewise, by the

Holding the commutator on its geometry at the on the

Winding process subsequent Axialverschiebungsschritt twisting of the commutator relative to the anchor packet can be safely avoided. Due to the higher positional accuracy of a fully assembled, formed according to the concept of the invention commutator characteristic fluctuations are reduced from electrical machine to electrical machine.

In a development of the invention, it is advantageously provided that the geometry (alignment geometry) of the commutator is arranged in a hub section of the commutator surrounding the passage opening radially on the outside. This hub portion (main body) is preferably made of plastic, for example by compression or injection molding, preferably as a sintered part. Preferably, the geometry is located at a radial distance from, preferably formed of copper, preferably arranged on the outer circumference, lamellae. It is conceivable to design the geometry with respect to an end plane of the commutator sublime and / or deepened. With regard to a minimization of the space, it is particularly preferable to have an exclusively recessed configuration of the geometry, that is to say axially, extending into the commutator.

In a further development of the invention is advantageously provided that the geometry (alignment geometry) of the commutator is designed as a tooth geometry with extending in the radial direction and circumferentially juxtaposed teeth. The provision of a multiplicity of teeth which are arranged next to one another in the circumferential direction makes it possible to securely support or pass on torques acting in the circumferential direction.

In order to be able to realize an exact alignment of the commutator relative to a further element, in particular to the anchor packet of an electrical machine, an embodiment is preferred in which the tooth geometry has a number of teeth corresponding to the number of lamellae. In other words, the number of not necessarily, but preferably, radially tapered teeth corresponds to the number of louver hooks for fixing and electrically contacting the armature winding, so that the relative position of a geometry cooperating displacement and / or alignment device defines exactly relative to each hook is. In this case, an embodiment in which the teeth are each arranged in a region in the circumferential direction between two adjacent lamellae or on a hook in each case is particularly preferred. Particularly preferred is an embodiment of the commutator in which the respective lamellae having lamellae are arranged on the outer circumference of the commutator, wherein the lamellae slots extend in the axial and radial directions. In other words, the lamellae form, at least in sections, preferably completely, the lateral surface of the, at least approximately, hollow-cylindrical commutator.

The invention also leads to a system comprising a commutator formed according to the concept of the invention. In addition to the commutator having an end-face geometry (alignment geometry), the system comprises a displacement and / or alignment device for axially displacing and / or rotating the commutator in the circumferential direction. In this case, the displacement and / or alignment device comprises a counter-geometry corresponding to the end-side geometry of the commutator, wherein the geometry and the counter-geometry are designed and matched to one another such that they can support torques acting in the circumferential direction. An embodiment of the system can be realized in which, in addition to the commutator, it has exclusively a displacement device or exclusively an alignment device, or else a displacement device and an alignment device. Particularly preferred is an embodiment of the system in which a combined displacement and / or alignment device is provided in addition to the commutator.

In order to be able to effect an exact alignment of the commutator to a further element, it is preferred if the counter-geometry of the displacement and / or alignment device is formed congruent to the frontal geometry of the commutator.

The displacement and / or alignment device can be a component of a mounting device for axially positioning the commutator relative to an armature package on the armature shaft and / or for aligning the commutator in the circumferential direction on the armature shaft relative to the armature core. The anchor package is preferably a sheet-metal lamination stack.

Additionally or alternatively, the displacement and / or alignment device may be a component of a production device, in particular a sawing device, wherein the displacement and / or alignment device in particular for aligning the commutator relative to at least one saw of the sawing device for introducing the slats electrically mutually insulating slat slots is formed.

Short description of the drawing

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and with reference to the drawing. This shows in the only one

1 shows a perspective view of a commutator with an end-face geometry for aligning the commutator in the circumferential direction.

Embodiment of the invention In Fig. 1, a commutator 1 for a non-illustrated, known per se electric machine, in particular for a small electric motor for adjustment tasks in motor vehicles, for example for a window lift drive shown. The commutator 1 consists of a base body 2 made of plastic, which forms a hub portion 4, which is bounded radially inwardly by the inner circumference of a running in the axial direction, circular contoured through hole 3. The passage opening 3 serves to receive an armature shaft of an electric machine, on which the commutator 1 is preferably fixed in a rotationally fixed manner by means of a press fit.

On the outer circumference of the base body 2, a plurality of circumferentially spaced lamellae 5 are arranged made of copper. In each case, two lamellae 5 arranged next to one another are separated from one another and thus electrically insulated from one another in the axial and also somewhat in the radial direction into the basic body 2 extending lamellar slots 6. The lamellae 5 are made of a metal strip which was anchored during spraying of the base body 2 in this. By introducing the slat slots 6 by means of a sawing device in the manufacture of the commutator 1, the individual slats 5 were made from the copper strip.

Each lamella 5 has an axially projecting, curved lamella hooks 7. The lamella hooks 7 are used for fixing and electrical contacting of an armature winding, not shown. The armature winding is clamped by hot caulking of the lamella hooks 7. The lamellae 5 form the lateral surface 8 of the substantially hollow-cylindrical commutator 1, which is interrupted by the lamellae slots 6, wherein sliding contacts, which electrically contact the lamellae 5, slide on the outer surface 8 during operation of the electrical machine.

In Fig. 1, the commutator 1 is shown in a view of an end face 9, which faces away from an anchor packet when mounted in the electric machine commutator 1. The front side 9 plays in the commutator 1 shown a crucial role both in the manufacture of the commutator 1, in particular during insertion (sawing) of the lamellae slots 6 and when joining the commutator 1 on the armature shaft, in particular during axial displacement of the commutator 1 after the winding process.

In the front page 9, a recessed geometry 10 is introduced. This is located in the main body 2 or in the hub portion 4 and was introduced as an integral geometry during the manufacture of the main body 2, in particular during injection molding, by a corresponding tool molding. The geometry 10 is aligned concentrically to the longitudinal central axis L of the commutator 1 and has a circumferential toothing structure 11 with a plurality of teeth 12 arranged next to one another in the circumferential direction. The number of teeth 12 corresponds to the number of lamellae 5 and thus the lamellae slots 6 and the lamellar hooks 7. The teeth 12 taper in the radial direction outwardly pointed, wherein between each two circumferentially spaced lamellae 5, a slat slot 6 is provided. The flanks 13, 14 of the teeth 12 of the toothing structure 11 form engagement surfaces for supporting a torque.

To the geometry 10 there is a not shown, corresponding, preferably conforming counter-geometry on a displacement and / or alignment, said counter-geometry is formed for the shown commutator 1 as a raised geometry with a tooth structure, wherein the teeth form congruent in as recesses formed teeth 12 of the geometry 10 can be inserted. From the counter-geometry to the flanks 13, 14 matching counter flanks (Gegenabstützflachen) are provided.

The displacement and / or alignment device can displace the commutator 1 axially along its longitudinal central axis L and prevent the commutator 1 from rotating about the longitudinal central axis L due to the engagement of the counter-geometry in the geometry 10. If the commutator 1 is to be aligned with another element, in particular an armature plate of the electric machine or a saw during the production of the commutator 1, the displacement and / or alignment device can rotate the commutator 1 about the desired angle of rotation about the longitudinal central axis L be realized.

Claims

claims

1. commutator for an electrical machine, with a plurality of juxtaposed by slat slots (6) separated slats (5) for interacting with sliding contacts and with a central through hole (3) for sliding the commutator (1) on an armature shaft of an electric motor,

characterized,

in that the commutator (1) has an end face geometry (10) designed for positive engagement with a displacement and / or alignment device.

2. Commutator according to claim 1, characterized in that the geometry (10) in a passage opening (3) radially outer surrounding hub portion (4) of the commutator (1), preferably during injection molding, is introduced.

3. Commutator according to one of claims 1 or 2, characterized in that the geometry (10) is raised and / or recessed formed.

4. Commutator according to one of the preceding claims, characterized in that the geometry (10) is formed as a tooth geometry with extending in the radial direction and in the circumferential direction adjacent teeth (12).

5. Commutator according to one of the preceding claims, characterized in that the tooth geometry has a number of lamellae (5) corresponding number of teeth (12).

6. Commutator according to claim 5, characterized in that the teeth (12) in each case in an area in the circumferential direction between two adjacent slats (5) or on a slat hook (7) are arranged facing.

7. Commutator according to one of the preceding claims, characterized in that the respective one lamella hooks (7) having, from each other over the axially extending louver slots (6) electrically insulated, lamellae (5) on the outer circumference of the commutator (1) are arranged ,

8. System comprising a commutator (1) according to any one of the preceding claims, whose frontal Geomet- rie (10) cooperates with a corresponding counter-geometry of a displacement and / or alignment means form fit.

9. System according to claim 8, characterized in that the counter-geometry is formed congruent with the geometry (10) of the commutator (1).

10. System according to any one of claims 8 or 9, characterized in that the displacement and / or alignment device part of a mounting device for the axial positioning of the commutator (1) relative to an anchor assembly on the armature shaft and / or for aligning the commutator ( 1) in the circumferential direction on the armature shaft relative to an armature core.

11. System according to one of claims 8 to 10, characterized in that the displacement and / or alignment device part of a sawing device for aligning the commutator (1) relative to a saw for introducing the slats (5) electrically mutually insulating slat slots (6 ).