WO2014195002A2

WO2014195002A2 - Stator for an electric motor

Info

Publication number: WO2014195002A2
Application number: PCT/EP2014/001476
Authority: WO
Inventors: Peter Pszola; Daniel FIEDERLING
Original assignee: Brose Fahrzeugteile GmbH & Co. Kommanditgesellschaft, Würzburg
Priority date: 2013-06-05
Filing date: 2014-06-02
Publication date: 2014-12-11
Also published as: WO2014195002A3; DE102013009407A1

Abstract

The invention relates to a stator (8) for an electric motor, having a star-shaped laminated stator core (13) and a cylindrical stator yoke (7) composed of stacked metal rings (1) in which the star-shaped laminated stator core (13) can be inserted or is inserted, wherein a number of the metal rings (1) each have at least one bending lug (3) on the outer circumference.

Description

description

Stator for an electric motor

The invention relates to a stator for an electric motor, with a star-shaped laminated stator core and with a cylindrical Statorjoch formed from stacked annular plates, in which the star-shaped stator lamination stack is used or used. It further relates to an electric motor with such a stator and a corresponding annular plate.

An electric motor as an energy converter of electrical energy into mechanical energy comprises a stator which forms the stationary motor part, and a rotor which forms the moving motor part. In an internal rotor motor, the stator is usually provided with a stator yoke, on which radially to the center, inwardly projecting stator teeth are arranged, whose rotor facing the free ends form the so-called pole piece. On the stator teeth windings are applied, which generate a magnetic field in the electromotive operation. For guiding and amplifying the magnetic field generated by the energized windings, the stator material is usually metallic, for example made of soft magnetic iron.

In order to avoid a complicated winding process, a multi-part structure of the stator is common. For this purpose, first of all a laminated core with star-shaped stator teeth is produced, which are connected to each other on the pole shoe via pole shoe webs, which are also referred to below as scattering segments, in order to achieve a mechanically stable bond. The stator is made of individual, stamped stator laminations by being packaged to the star-shaped sheet stack in a mechanically stable composite.

Following the assembly of the externally accessible stator teeth with the windings (coil windings), the laminated core is inserted into the stator yoke forming a yoke ring and joined by means of compression or shrinkage. Such a stator is known from DE 10 2009 056 647 A1.

CONFIRMATION COPY When mounting the electric motor with such a stator of this is pressed or shrunk over the entire axial stator length in a cylindrical housing (motor housing) using decoupling rings, which disadvantageously requires the provision of separate decoupling rings and a correspondingly complex joining operation.

The invention has for its object to provide a particularly suitable stator for an electric motor while avoiding the disadvantages mentioned. Here, the stator should be simple and - especially with regard to a necessary centering - reliable in a housing can be used or mounted.

This object is achieved by the features of claim 1. Advantageous embodiments and further developments are the subject of the dependent claims.

For this purpose, the stator provided for an electric motor has a star-shaped laminated stator core made of axially stacked stator laminations and a cylindrical stator yoke formed from stacked annular laminations into which the star-shaped laminated stator core can be inserted. The or individual ring plates are provided on the outside circumference each with at least one subsequently also referred to as a clamping or sheet metal tab or as a clamping or sheet nose bending tab.

The advantageously formed in the course of the punching process of the ring plates circumferentially bending tabs extend in the initial state, preferably radially and can - relative to the central stator or motor axis - are bent axially. Within the annular plate stack, the ring plates are expediently arranged mutually rotated relative to each other about the central stator or motor axis by a certain angle. As a result, one or more bending tabs can be positioned in certain circular sectors along the corresponding circular arcs. The bending tabs will be positioned on the outer circumference of the respective ring plate in such a way that they generate additional pressing forces in the assembled state of the stator and bring about improved thermal and / or mechanical contact between the stator teeth and the stator yoke. This also allows an improved acoustic behavior of the stator and thus of the electric motor having this. For this purpose, the bending tabs in the assembled state of the stator can be aligned with its stator teeth. Also, the bending tabs can be positioned on the outer peripheral side in each case between two adjacent stator teeth.

The arranged on the outer circumference of the ring plates and thus the Statorjochs bending tabs further allow compensation of expansion differences between the stator and a motor housing of the electric motor due to temperature influences. This is particularly advantageous if these components consist of different materials or materials, such as steel or aluminum, with different coefficients of expansion.

Particularly preferred within the annular sheet stack are provided only in the axially upper and lower region with such bending tabs provided ring plates, suitably rotated against each other. Also, in addition or alternatively, such bending tabs or ring laminations may be provided with such bending tabs only in the axially middle region of the annular sheet stack. In addition, the bending tabs within the annular plate stack and thus on the outer circumference of the Statorjochs arranged spirally stiffened, d. H. be positioned.

The ring plates also advantageously have outer peripheral side ratcheting. Within the annular plate stack these notches correspond with bending tabs of axially adjacent annular plates such that the bending tabs at least partially engage in the course of their bending into the notches and thus do not protrude peripherally or only comparatively slightly out of the stack periphery of the annular plate stack. Suitably, the number of notches of a corresponding ring plate is greater than the number of bending tabs. For example, a total of one of the number of the star-shaped Stator laminated core formed stator teeth corresponding number of bending tabs and notches can be provided. For example, in a suitable embodiment, the number of bending tabs is three, while the number of notches is nine. In this embodiment, the stator lamination stack has, for example, twelve stator teeth.

The bending tabs serve primarily as spacers and / or contact points of the stator via its stator yoke formed by the annular stack of stacks with respect to a housing (motor housing) into which the stator is inserted in the course of assembly. In this context, the bending tabs preferably form in the axially upper and lower and additionally or alternatively in the axially middle region, for example, three azimuthally equidistant exposed contact points with which the stator yoke with integrated laminated stator core rests against the housing on the inside. Also, a spiral arrangement in the axial direction of bending tabs and thus a practically approximately point-like positioning of abutment points on the outer circumference of the stator yoke as a suitable embodiment is conceivable.

The advantages achieved by the invention are in particular that by means of the ring plates of a Statorjochs formed of a ring plate stack stator with star-shaped Statorblechpaket circumferentially molded, radially extending bending tabs a reliable fixation at the same time automatic centering and reliable positioning of the stator is made possible in a housing , The stator is in the joining state only with provided at exposed points investment points, which are formed by the bending tabs, on the Gehäuseinnenwandung. A full system of the stator on the inner wall of the housing is thus reliably avoided. In addition, the use of separate decoupling rings is not required.

In the course of the joining process of the stator with the housing, the bending tabs are bent axially. This allows the automatic centering of the stator in the housing. Are the individual ring laminations provided with notches into which the bending tabs are inserted before or during the joining process of the stator with the Housing can be inflected, also allows a particularly space-saving design of an electric motor with a stator inserted in the housing.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

Fig. 1 in perspective view a ring plate with circumferentially radial

Bending ears,

2 is a perspective exploded view of four axially superposed and against each other twisted ring plates of FIG. 1,

Fig. 3 is a side view of a formed from ring plates of FIG. 1 ring stack as Statorjoch in a direction indicated in a schematic sectional view of the housing, and

4 shows a perspective view of a stator with a stator yoke according to FIG. 3 and star-shaped laminated stator core inserted therein.

Corresponding parts are provided in all figures with the same reference numerals.

Fig. 1 shows a stator or return ring plate 1 with an annular sheet metal body 2 and on the outer peripheral side integrally formed, hereinafter referred to as bending tabs 3 sheet metal or clamping straps (clamping lugs). In the exemplary embodiment, three such sheet metal tabs 3 are distributed uniformly on the circumference, ie, offset from each other at an angle of 120 °. In the embodiment, a total of nine such notches 4 are provided, of which three notches 4 are provided between two adjacent sheet metal tabs 3. On the inner peripheral side, a number of obtuse-angled notches 5 are introduced into the annular sheet-metal body 2. The annular plate 1 is a manufactured by punching single sheet for Production of a stator yoke 6 shown in FIGS. 3 and 4 of a stator 7 for an electric motor.

Fig. 2 shows a number of four in the embodiment, in the axial direction A superposed ring plates 1, the bending tabs 3 extending in the radial direction R. The ring plates 1 are arranged around a dashed line indicated central axis 8 to a certain, same angular amount of 30 ° in the embodiment rotated against each other. Visible aligned with each sheet metal tab 3 one or more notches 4 axially adjacent ring plates 1. When bending the metal tabs 3 in the axial direction A, these can thus at least partially engage in the notches 4. Also, for example, individual metal tabs 3 are completely inflected into the notches 4.

The ensemble shown with four ring plates 1, for example, can form an axially upper and / or lower stack section 9a or 9b of a ring plate stack 10 produced from a plurality of ring plates 1, which is shown in FIG. Within this respective stacking section 9a, 9b, the metal tabs 3 are arranged practically helically along the stack periphery.

The annular sheet stack 10 shown in FIG. 3 is formed from a multiplicity of ring laminations 1, wherein annular laminations with bending tabs 3 are provided only in the axially upper and upper stack area 9a and lower stack area 9b. The central stack area of the annular sheet stack 10 may be designed with ring plates without bending tabs. Also provided in this middle stack area ring plates 1 may be used with bending tabs 3, then suitably at least some, preferably all remaining bending tabs 3 are inflected into the associated notches 4.

The annular sheet stack 10 shown in Fig. 3 is inserted into a housing 11 indicated in longitudinal section. The housing 11 is for example a pot-like motor housing. Recognizable form the particular in the upper and lower stacking section 9a and 9b arranged ring plates 1 by means of bent in the axial direction A bending tabs 3 practically point-shaped contact points 12 of the Stator yoke 6 forming annular sheet stack 10 on the housing 11, ie on the inner wall. The contact points 12 formed by the bending tabs 3 are designated as such in FIG. 3 only in the four corner regions between the housing 11 and the annular sheet stack 10.

The annular sheet stack 10 is automatically centered within the housing 11 in the course of the insertion or joining of the annular sheet stack 10 as a stator yoke 6 having stator 7 in the housing 11. The bending of the bending tabs 3 can take place before or during the insertion of the ring plate stack 10 having stator 7 in the housing 11. With the exception of the punctiform contact points 12, which are formed by the corresponding bending tabs 3, the remaining areas of the annular sheet stack 10 are not contacted with the inner wall of the housing 11. In other words, the predominant circumferential or circumferential region of the annular sheet stack 10 does not abut against the inner wall of the housing 11. This non-contact region of the annular sheet stack 10 with respect to the inner wall of the housing 11 is symbolized as distance D.

FIG. 4 shows a perspective view of the stator yoke 6 formed from the annular sheet stack 10 with the plurality of individual ring laminations 1 into which a star-shaped laminated stator core 13 is inserted. This has a number of twelve stator teeth 14 in the exemplary embodiment. These stator teeth 14, which in turn are formed from individual sheets, are provided with obtuse-angled tips 15 on the free-end side, which correspond to the obtuse-angled notches 5 of the ring laminations 1 or of the annular sheet stack 10 and thus of the stator yoke 6.

A pole shoe 16, which is common to the stator teeth 14 on the inner peripheral side, is provided with pole shoe-side gaps 17, which are delimited by the pole shoe webs 18. The pole piece 16 of the stator 8 shown in FIG. 4 delimits a central, cylindrical opening 19, which surrounds the rotor of the electric motor in a manner not shown, and in which the rotor around the central stator or motor axis 8 during operation of the electric motor rotates. The invention is not limited to the embodiment described above. Rather, other aspects of the invention may be deduced therefrom by those skilled in the art without departing from the scope of the invention. In particular, individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without leaving the article.

LIST OF REFERENCE NUMBERS

1 ring plate

2 sheet metal body

3 clamping / bending tab

4 notch

5 notch

6 stator yoke

7 stator

8 stator / motor shaft 9a upper stack section 9b lower stack section

10 ring stacks

11 housing

12 investment point

13 stator core

14 stator tooth

15 tip

16 pole shoe

17 gap

18 pole piece

19 cylindrical opening

A axial direction

D distance

R radial direction

Claims

claims

Stator (7) for an electric motor, with a star-shaped laminated stator core (13) and with a cylindrical stator yoke (6) formed from stacked ring laminations (1) into which the star-shaped laminated stator core (13) can be inserted or inserted,

characterized,

a number of the ring plates (1) has at least one bending tab (3) on the outer peripheral side in each case.

Stator (7) according to claim 1,

characterized,

that the respective bending tab (3) extends in the radial direction (R) and in the axial direction (A) is bendable.

Stator (7) according to claim 1 or 2,

characterized,

that the ring plates (1) in the ring plate stack (10) against each other twisted are arranged axially one above the other.

Stator (7) according to one of claims 1 to 3,

characterized,

in that the bending tabs (3) are arranged at different azimuthal and / or axial positions of the annular sheet stack (1).

Stator (7) according to one of claims 1 to 4,

characterized, the ring plates (1) have a number of notches (4) on the outer peripheral side.

6. stator (7) according to claim 5,

characterized,

in that the ring laminations (1) are arranged oriented within the annular sheet stack (10) in such a way that the bending tabs (3) are aligned with notches (4) of axially adjacent annular laminations (1).

7. stator (7) according to claim 5 or 6,

characterized,

in that the bending tabs (3) are at least partially inflected into axially adjacent notches (4) within the annular sheet stack (10).

8. annular plate (1) for a stator yoke (6) of a stator (7), with at least one circumferential bending tab (3).

9. ring sheet stack (10) of ring plates (1) according to claim 8, wherein the bending tabs (3) of the ring plates (1) are arranged at axially and / or at circumferentially different positions.

10. Electric motor with a housing (11) for receiving a stator (7) according to one of claims 1 to 7,

characterized,

that the bending tabs (3) of the annular plates (1) of the annular plate stack (10) are axially bent when the stator (7) is inserted into the housing (11), the stator (7) being housed only with the or some of the bending tabs (3). inside the housing (11) rests.