WO2008040642A1

WO2008040642A1 - Laminate stack of an electrical machine

Info

Publication number: WO2008040642A1
Application number: PCT/EP2007/059974
Authority: WO
Inventors: Gerald Roos
Original assignee: Robert Bosch Gmbh
Priority date: 2006-10-04
Filing date: 2007-09-20
Publication date: 2008-04-10
Also published as: DE102006046904A1

Abstract

The invention relates to a laminate stack of an electrical device, in particular an electrical machine, with a large number of faces which rest flat one on the other and are connected to one another. It is provided that, in order to reduce eddy currents, in each case only a fraction of the total number of laminates (8) of the laminate stack (3) are connected to one another so as to form partial laminate stacks (A, B, C, D, E, F, G, H) in each case by means of at least one partial connection (11), and that the partial connections (11) of adjacent partial laminate stacks (A, B, C, D, E, F, G, H), when viewed in the plane of the laminate, are positioned at a distance in relation to one another.

Description

description

Title BLECH PACKAGE OF AN ELECTRICAL MACHINE

The invention relates to a laminated core of an electrical device, in particular an electric machine, with a plurality of flat superposed, interconnected sheets.

State of the art

A laminated core of the type mentioned is known. It serves, for example, as an armature of an electrical machine, such as a DC motor. Such an armature is provided with armature windings and is constructed to reduce eddy currents occurring during operation of the electrical machine as a laminated core. The sheets of the laminated core are electrically isolated from each other, this insulation is lifted at joints where the sheets are interconnected. In general, all the laminations of the laminated core are connected to each other by all the laminations in sheet stacking axially continuous connections, creating a stable laminated core that is "plated" through the joints Due to the "plated-through hole" at the connection points, however, the eddy currents during operation of the electric machine are quite high and there are significant eddy current losses.

Disclosure of the invention

In the inventively designed laminated core is provided that for reducing eddy currents in each case only a part number, the total number of sheets of the laminated core to form partial laminated cores are each connected by at least one partial connection and that the partial connections of adjacent partial laminated cores - seen in the sheet metal plane - with distance to each other. The sheets of the laminated core are connected by means of partial connections to partial laminated cores, wherein there is at least one connecting plate per connection of two partial laminated cores, which is assigned to two partial laminated cores. In this case, the partial connection of this connection plate with one partial plate stack - as seen in the plane of the plate - is arranged at a distance from the partial connection of the connecting plate with the other partial plate packet. The partial connections of the partial laminated cores together ensure that all sheets of the laminated core are connected to each other. The sheets of each partial lamination stack can be connected to each other in the sheet stacking direction (axially) continuously

However, the connection from one partial plate packet to an adjacent partial plate packet always takes place via a partial connection which is spaced apart in the plane of the metal sheet This results in an increase of the electrical resistance of the eddy currents and a reduction in the eddy current loss, whereby the eddy currents within the laminated core are created by induction.

Furthermore, it is provided that each partial connection is designed as a mechanical connection and an electrical connection. By connecting the total number of sheets of the laminated core by means of partial connections all sheets of the laminated core are mechanically connected to each other, so that the laminated core forms a unit. In addition to the mechanical connection results in an electrical connection via the sub-connections, so that each sheet metal of the laminated core is electrically connected to each other sheet of the laminated core.

In particular, it is provided that the sheets have an insulating coating on their surface. This insulating coating is used for electrical insulation and is only interrupted at the sub-connections, so that results in the spaced position of the partial connections of adjacent partial plate stacks an extended current path of the eddy currents. According to a development of the invention it is provided that the laminated core is a core body of a rotor or stator of the electrical device, wherein the core body has circumferentially arranged grooves and teeth. The electrical device is preferably an electrical machine, such as an electric motor or a generator. The core body is provided with at least one winding. The winding is provided with sections provided in the grooves of the core body. In such a core body of the electrical device produced during operation by eddy currents occurring eddy current losses, which reduce the efficiency of the electrical device. The material of the sheets is a ferromagnetic material, preferably an iron alloy.

It is advantageously provided that the partial connection is a stamped connection. Since the sheets are preferably made by punching, each of the partial joints can be easily manufactured by stamping.

Furthermore, it is provided that the partial connection of the partial laminated cores takes place in each case in the region of the teeth. This partial connection is preferably located at the respective end of the teeth, the so-called tooth heads. If the laminated core is designed, for example, as an armature of a rotor, then the partial connection takes place in particular on the outer circumference of the teeth. For the production of the partial compounds parts of the preferably stamped sheets are connected by stamped packetization to partial laminated cores.

It is advantageously provided that the distance between the partial connections of adjacent partial laminated cores corresponds at least to a distance from one tooth to a circumferentially adjacent tooth. Adjacent partial laminated cores may have, for example, at least one common connecting plate, which is connected within the one partial laminated core in the region of a tooth by means of a partial connection and is connected within the other partial laminated core by means of another partial junction in the region of an adjacent tooth. In this case, the sheets of a partial laminated core are preferably connected to one another by a plurality of partial connections. The distance between these partial connections within a partial laminated core is preferably at least as great as the distance from one tooth to the next but one Tooth of the core body. Due to this greater distance within each of a partial laminated core, a high mechanical stability is achieved within the partial laminated core.

Furthermore, it is provided that each of the partial laminated cores has at least two sheets. In the case of two metal sheets per partial laminated core, each of these metal sheets can serve as a connecting sheet to a respective adjacent partial sheet metal core. In this case, the resulting laminated core in particular complete with a single, no laminated core associated sheet.

Finally, it is provided that each of the partial laminated cores has the same number of sheets or approximately the same number of sheets. Due to the uniform thickness of the partial laminated cores, with a uniform electrical resistance, a particularly stable laminated core can be produced.

Brief description of the drawings

The invention will be explained in more detail with reference to the accompanying drawings. Show it:

FIG. 1 shows a side view of a ten-tooth laminated core designed as a rotor of an electrical machine,

FIG. 2 shows a plan view of a tooth tip of one of the teeth of the rotor of FIG. 1,

3 shows a plan view of a tooth tip of a tooth and a plan view of a tooth tip of another, adjacent tooth of a laminated core according to a first exemplary embodiment,

4 shows a plan view of a tooth head of a tooth and a plan view of a tooth tip of another, adjacent tooth of a laminated core according to a second embodiment, and 5 shows a plan view of a tooth tip of a tooth and a plan view of a tooth tip of another, adjacent tooth of a laminated core according to a third embodiment.

Description of the embodiments

FIG. 1 shows a laminated core 3, which is designed as a core body 1 of a rotor 2, of a not completely illustrated electrical device 4 in a side view. The core body 1 has ten teeth 5, 5 'and ten respectively between the teeth 5, 5' arranged grooves 7. Each tooth 5, 5 'has at its the outer periphery of the core body 1 end facing a widened tooth head 6. In the side view of Figure 1, only the first sheet 8 of the laminated core 3 is visible.

FIG. 2 shows a non-inventive connection 9 of the sheets 8 in the region of the tooth head 6 of a tooth 5, 5 'of the core body 1. The sheets 8 designed as stamped sheets are connected to the tooth head 6 by stamped packetization to form a laminated core 3. The connection 9 connects axially (perpendicular to the metal planes) continuously all the sheets 8 of the laminated core 3. In this case, all the sheets 8 are connected directly and without spacing in the sheet metal plane mechanically and electrically. Outside the connection 9, the sheets 8 are electrically insulated from each other. The insulation takes place via an electrically insulating coating 10 on the surface of the sheets 8. The axial "through-connection" of the connection 9 results in operation of the electrical device 4 eddy currents and associated eddy current losses.

FIG. 3 shows a tooth 5 at the top and a tooth 5 ', adjacent to the tooth 5, at the bottom, of a laminated core 3 according to the invention in a first exemplary embodiment. The two teeth 5, 5 'are exemplary of the odd teeth 5 and the straight teeth 5' of the laminated core 3. The laminated core 3 of the embodiment of Figure 3 has seventeen plates 8.1 - 8.17. In the odd teeth 5 (Figure 3 above) form the second plate 8.2 and the third plate 8.3 a partial plate package B, the fourth plate 8.4 and the fifth plate 8.5 a partial plate package D, the sixth plate 8.6 and the seventh Sheet 8.7 a partial laminated core F, the eighth sheet 8.8 and the ninth sheet 8.9 a partial laminated core H, the tenth sheet 8.10 and the eleventh sheet 8.11 a partial laminated core J, the twelfth sheet 8.12 and the thirteenth sheet 8.13 a partial laminated core L, the fourteenth sheet 8.14 and the fifteenth plate 8.15 a partial plate package N and the sixteenth plate 8.16 and the seventeenth plate 8.17 a partial plate package P. In the straight teeth 5 '(Figure 3 below), the sheet is 9.1 with the partial plate package B through the partial connection 11 of the partial laminated core A, the partial laminated core B with the partial laminated core D through the partial connection 11 of the partial laminated core C, the partial laminated core D with the partial laminated core F through the partial connection 11 of the partial laminated core E, the partial laminated core F with the partial laminated core H through the partial connection 11 of the partial laminated core G, the partial laminated core H with the partial laminated core J. through the partial connection 11 of the partial laminated core I, the partial laminated core J with the partial laminated core L through the partial junction 11 of the partial laminated core K, the partial laminated core L with the partial laminated core N through the partial connection 11 of the partial laminated core M, as well as the partial laminated core N with the partial laminated core P through the partial connection 11 of the partial laminated core O connected. The partial connections 11 within the individual partial laminated cores B, D, F, H, J, L, N, P are located respectively on the tooth head 6 of the one teeth 5 (odd teeth) and on the partial laminated cores A, C, E, G, I, K, M, O on the tooth head 6 of the adjacent teeth 5 '(straight teeth). In this case, the partial connections 11 of the plates 8 formed as stamped plates are realized by stamped packetization.

FIG. 4 shows at the top the odd-numbered teeth 5 and at the bottom the straight teeth 5 'of a core body 1 of the electrical device 4 formed from a laminated core 3 with the sheets 8.1 to 8.19 in a second exemplary embodiment. In the odd teeth 5 form by partial connections 11, the first sheet 8.1, the second sheet 8.2 and the third sheet 8.3 a sheet package A, the fourth sheet 8.4, the fifth sheet 8.5, the sixth sheet 8.6 and the seventh sheet 8.7 a laminated core C, the eighth plate 8.8, the ninth plate 8.9, the tenth plate 8.10 and the eleventh plate 8.11 a partial plate package E, the twelfth plate 8.12, the thirteenth plate 8.13, the fourteenth plate 8.14 and the fifteenth plate 8.15 a partial plate package G and the sixteenth plate 8.16 , the seventeenth plate 8.17, the eighteenth plate 8.18 and the nineteenth plate 8.19 a partial laminated core I. Starting from the in the odd teeth 5 contacted partial laminated cores A, C, E, G, I these are in the straight teeth 5 'by partial connections 11 of the partial laminated cores B, D, F, H, J contacted with each other. The partial laminated core A is connected to the partial laminated core C by the partial connection 11 between the first metal sheet 8.1, the second metal sheet 8.2, the third metal sheet 8.3 and the fourth metal sheet 8.4 (partial laminated core B), the partial laminated core C with the partial laminated core E through the partial connection 11 between the fifth plate 8.5, the sixth plate 8.6, the seventh plate 8.7 and the eighth plate 8.8 (partial plate package D), the partial plate package E and the partial plate package G through the partial connection 11 between the ninth plate 8.9, the tenth plate 8.10, the eleventh 8.11 sheet metal and the twelfth sheet 8.12 (partial laminated core F) connected and the partial laminated core G and the partial laminated core I through the partial connection 11 between the thirteenth plate 8.13, the fourteenth plate 8.14, the fifteenth plate 8.15 and the sixteenth plate 8.16 (Part H plate) connected. At the partial laminated core I closes the

Partial laminated core J to that a partial connection between the seventeenth plate 8.17, the eighteenth plate 8.18 and the nineteenth plate 8.19. Also in this embodiment, the partial connections 11 of the sheet metal formed as stamped plates 8 are realized by stamped package. The sheets 8 are provided with on their surface in each case with an insulating coating 10 which the sheets 8 with each other. Only at the partial connections there is a contacting of the sheets. 8

FIG. 5 shows a further embodiment in which the laminated core 3 is shown in FIG. 5 at the top in the odd-numbered teeth 5 and in FIG. 5 at the bottom in the straight teeth 5 '. By partial connections 11 in the odd teeth 5, the first sheet 8.1, the second sheet 8.2 and the third sheet 8.3 form a sheet package A, the fourth sheet 8.4, the fifth sheet 8.5, the sixth sheet 8.6, the seventh sheet 8.7, the eighth sheet 8.8, the ninth plate 8.9, the tenth plate 8.10 and the eleventh plate 8.11 a partial plate packet C, the twelfth plate 8.12, the thirteenth plate 8.13, the fourteenth plate 8.14, the fifteenth plate 8.15, the sixteenth plate 8.16, the seventeenth plate 8.17, the eighteenth sheet 8.18 and the nineteenth sheet 8.19 a partial laminated core E. Starting from the definition of the partial laminated cores A, C, E on the partial connections 11 in the odd teeth 5, the result Partial connections 11 of the adjacent partial lamination packages A and C in the straight teeth 5 'by a partial connection of the first sheet 8.1, the second sheet 8.2, the third sheet 8.3, the fourth sheet 8.4, the fifth sheet 8.5, the sixth sheet 8.6 and the seventh sheet 8.7 of the partial laminated core B. The adjacent partial laminated cores C and E are in the straight teeth 5 'via a partial connection 11 between the eighth plate 8.8, the ninth plate 8.9, the tenth plate 8.10, the eleventh plate 8.11, the twelfth plate 8.12, the thirteenth Sheet 8.13, the fourteenth sheet 8.14 and the fifteenth sheet 8.15 of the partial laminated core D given. The partial laminated core E is adjoined to the partial laminated core E in that the partial connection 11 in the straight teeth 5 'connects the sixteenth sheet 8.16, the seventeenth sheet 8.17, the eighteenth sheet 8.18 and the nineteenth sheet 8.19. Also in this embodiment, the partial connections 11 of the sheet metal formed as stamped plates 8 are realized by stamped package. The sheets 8 are provided with an insulating coating 10 on their surface.

This results in the following function of the formation of partial laminated cores A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P and their partial compounds 11 with each other: Since in the inventive Embodiments of Figures 3, 4 and 5, the laminated core 3 is divided into partial lamination packages A to P (or A to J and A to F), which are plated within the respective partial lamination stack in the odd teeth 5 on the tooth head 6, but only in the straight Teeth 5 'are contacted with each other, there is a current path of the eddy currents through the laminated core 3, which leads alternately through the odd teeth 5 and the straight teeth 5'. This results in a significantly longer current path compared to a completely plated-through laminated core, as shown for example in FIG. The lengthening of the current path results in increased resistance, so that the eddy current and associated eddy current losses within the laminated core 3 are reduced.

Claims

claims

1. laminated core of an electrical device, in particular an electric machine, with a plurality of flat superposed, interconnected sheets, characterized in that to reduce eddy currents in each case only a part number of the total number of sheets (8) of the laminated core (3) for the formation of Partial laminated cores (A ₁ B ₁ CD ₁ E ₁ F ₁ G ₁ H ₁ I ₁ J ₁ K ₁ L ₁ M ₁ N ₁ O ₁ P) are connected to each other by means of at least one partial connection (11) and that the partial connections (11) adjacent partial lamination packages (A ₁ B ₁ CD ₁ E ₁ F ₁ G ₁ H ₁ I ₁ J ₁ K ₁ L ₁ M ₁ N ₁ O ₁ P) - as viewed in the sheet metal plane - lie at a distance from each other.

2. laminated core according to claim 1, characterized in that the partial connection (11) is designed as a mechanical connection and an electrical connection.

3. laminated core according to one of the preceding claims, characterized in that the sheets (8) on their surface an insulating coating (10).

4. laminated core according to one of the preceding claims, characterized in that the laminated core (3) is a core body (1) of a rotor (2) or stator of the electrical device (4), wherein the core body (1) circumferentially arranged grooves (7) and teeth (5,5 ').

5. laminated core according to one of the preceding claims, characterized in that the partial connections (11) of the partial laminated cores (A ₁ B ₁ CD ₁ E ₁ F ₁ G ₁ HJ ₁ J ₁ K ₁ L ₁ M ₁ N ₁ O ₁ P) each in the area of the teeth (5,5 ') takes place.

6. laminated core according to one of the preceding claims, characterized in that the distance between the partial connections (11) of adjacent partial laminated cores (A ₁ B ₁ CD ₁ E ₁ F ₁ G ₁ HJ ₁ J ₁ K ₁ L ₁ M ₁ N ₁ O ₁ P) corresponds to at least one distance from a tooth (5) to a circumferentially adjacent tooth (5 ').

7. laminated core according to one of the preceding claims, characterized in that the partial connection (11) is a punched connection.

8. laminated core according to one of the preceding claims, characterized in that each of the partial laminated cores

(A ₁ B ₁ CD ₁ E ₁ F ₁ G ₁ H ₁ I ₁ J ₁ K ₁ L ₁ M ₁ N ₁ O ₁ P) has at least two sheets (8).

9. laminated core according to one of the preceding claims, characterized in that each of the partial laminated cores (A ₁ B ₁ CD ₁ E ₁ F ₁ G ₁ H ₁ I ₁ J ₁ K ₁ L ₁ M ₁ N ₁ O ₁ P) the same number of sheets (8) or approximately the same number of sheets (8).