WO2008142001A2

WO2008142001A2 - Module for the primary part of an electric machine

Info

Publication number: WO2008142001A2
Application number: PCT/EP2008/055983
Authority: WO
Inventors: Zeljko Jajtic; Michael Menhart
Original assignee: Siemens Aktiengesellschaft
Priority date: 2007-05-21
Filing date: 2008-05-15
Publication date: 2008-11-27
Also published as: WO2008142001A3; DE102007023606A1

Abstract

The invention relates to a module (1) for a primary part (14) of an electric machine. Said module (1) has at least one coil (2) and a permanent magnet (3) and a thermal contact resistance (6) is formed between the coil (2) and the permanent magnet (3).

Description

description

Tooth module for a primary part of an electrical machine

The invention relates to a tooth module for a primary part of an electrical machine, wherein the tooth module has at least one coil and a permanent magnet. Furthermore, the invention relates to a primary part with one or more tooth modules and an electrical machine with a primary part, which has one or more tooth modules.

Electrical machines have a primary part and a secondary part. In this case, electrical machines can be constructed in such a way that the primary part and / or the secondary part can have permanent magnets. The primary part is the part which has electrically energizable windings. The primary part is formed for example as a stator of a rotary electric machine or as a moving part of a linear electric machine with a single or multi-phase winding. The secondary part is, for example, a rotor of a rotary electric machine or a fixed part of a linear motor. In linear motors, both the primary part and the secondary part may be formed as a moving part.

Stator and rotor for electrical machines generally have a laminated core, consisting of individual electric sheets, wherein the winding or permanent magnets for generating magnetic fields are arranged on the laminated core. The individual sheets for stator and rotor are usually individually punched and joined together, for example via stamping package, welding, stapling or riveting to laminated cores.

In order to guide the main magnetic flux between the stator and the rotor, toothed plates are usually used in winding-carrying stators and / or rotors. In grooves of the laminated core, the winding is arranged. From DE 10 2004 045 992 Al an electric machine is known whose secondary part has no active means, such as energizable windings or permanent magnets, for generating magnetic fields. In a permanent magnet synchronous linear motor with a permanent magnet-free secondary part, the primary part energizable windings and permanent magnets, the secondary part having only a tooth structure of, for example, a ferrous material.

From WO 2007/033857 Al a tooth module for a permanent magnet excited primary part of an electric machine is known, wherein the tooth module has a permanent magnet and a coil. By means of such tooth modules, a primary part of an electrical machine can be modularly constructed.

Since the coil or the winding is arranged directly on the tooth module, there is a thermal coupling between the coil and the permanent magnet in the tooth module. However, such a thermal connection between the coil and the permanent magnet is disadvantageous since the integrated permanent magnets may only be heated up to a specified temperature. Exceeding this specified temperature there is a risk that the permanent magnets are damaged. Furthermore, such strong permanent magnets are expensive, the cost of the permanent magnets increases, the higher this specified temperature is applied. So far, attempts have been made, inter alia, to achieve the best possible heat coupling from the winding to the laminated core. The heat can then be applied to the surface via the laminated core, e.g. via air cooling, or to other cooling elements, e.g. a water cooling, be dissipated.

The object of the present invention is to provide a tooth module for an electrical machine, which is designed such that excessive heating of the permanent magnet is avoided. Other objects of the invention are to provide a primary part and an electric machine with such a tooth module.

This object is solved by the features of claims 1, 15 and 16. Advantageous developments can be found in the dependent claims.

The tooth module according to the invention for a primary part of an electrical machine has at least one coil and a permanent magnet, wherein a thermal contact resistance is formed between the coil and the permanent magnet.

A thermal contact resistance or heat transfer resistance arises between at least two different materials or media. The thermal contact resistance is dependent on the heat-transferring surface and the surface condition, the temperature and the contact pressure.

According to the invention, the coil and the permanent magnet are thermally decoupled from each other, which ensures that the permanent magnet heats only minimally or to a small extent. As a result, the permanent magnet is spared and its life extended. In addition, more cost-effective permanent magnets can be used by forming a thermal contact resistance, since now only a slight warming of the permanent magnet occurs. Alternatively, but could also be a stronger energization of the coil.

Advantageously, the tooth module has a first laminated core and a second laminated core. Each laminated core has a plurality of individual electrical sheets. The permanent magnet is arranged on the first laminated core and the coil on the second laminated core. Due to the formation of at least two laminated cores, each of which carries a means for generating magnetic fields, a first thermal decoupling of coil and permanent magnet already takes place. Preferably, the first laminated core and the second laminated core are formed such that the thermal contact resistance between the two laminated cores is present.

Such a thermal contact resistance can be formed, for example, by means of a narrow air gap between the permanent magnet-carrying first laminated core and the coil-carrying second laminated core. Such an air gap is at least partially present between the first and second sheet metal package. Preferably, the air gap is formed so that a thermal contact resistance is formed over the portion in which the permanent magnet and the coil face each other and have a small or small distance from each other. However, this air gap is formed over as long as possible.

In a further embodiment, the thermal contact resistance can also be formed by means of a thermally and / or electrically insulating material between the first and second laminated core. Such material may be plastic, for example.

The resulting in operation of the electrical machine heat loss in the coil is derived from the second laminated core carrying the coil. The heat is then dissipated to the surface or to other cooling elements, such as cooling coil, cooling plate, or water cooling via the coil-carrying laminated core.

The second laminated core preferably has one or more cooling elements for cooling the coil. Such a cooling element is for example a cooling tube, wherein the cooling tube, for example, with a cooling medium, for example water, flows through. Such cooling elements in the coil-carrying laminated core are advantageous, since in the coil during operation of the electrical machine, in particular a linear motor, high heat loss is generated, which can affect the operation or the operating time of the electrical machine. In a further embodiment of the invention, the tooth module is constructed in several parts. It is the first laminated core and the second laminated core each constructed at least two parts. The first laminated core, on which the permanent magnet is arranged, has two laminated core halves, which are arranged perpendicular to a running direction of the primary part next to each other and wherein the permanent magnet between the laminated core halves is also arranged perpendicular to the direction. Such a structure of the first laminated core allows a simple arrangement of the permanent magnet in the tooth module. Of the

Permanent magnet can be inserted for example between the laminated core halves.

The second laminated core, which carries the coil is also constructed at least in two parts, wherein the two laminated core halves are also arranged perpendicular to a direction of the primary part next to each other. In particular, the two laminated core halves of the second laminated core are arranged such that in each case a laminated core part of the second laminated core is arranged next to a laminated core part of the first laminated core. The two laminated core halves of the second laminated core abut respectively on the outer sides of the laminated core halves of the first laminated core. Both the first and the second laminated cores could also be constructed in one piece.

The tooth module preferably has a fastening groove for attaching the tooth module to a housing of the primary part. For this purpose, for example, has a housing part a corresponding counterpart, which is referred to as a sliding block, on, wherein the sliding block engages in the mounting groove of the tooth module.

A primary part according to the invention for an electrical machine has one or more tooth modules, which each have a thermal contact resistance between the coil and the permanent magnet. In this case, a plurality of tooth modules are preferably arranged side by side in the running direction. In this case, any number of tooth modules can be arranged. By such Tooth modules can be modular build a primary part, whereby various variants can be provided with respect to, for example, the length of a primary part.

The electric machine according to the invention has a primary part and a secondary part, wherein the primary part and the secondary part are spaced apart by an air gap. The electric machine in this case has a primary part, which is composed of several tooth modules according to the invention. Since the primary part already has a plurality of active means for generating magnetic fields, the secondary part has no active means for generating magnetic fields, but is merely a toothed structure, for example made of iron.

The electric machine is preferably designed as a permanent magnet synchronous linear motor. The primary part is designed as a moving part, wherein the tooth modules according to the invention are arranged next to one another in the direction of the linear motor and essentially form the primary part. Such moving primary parts can be produced inexpensively, since the permanent magnets are present only in the primary part and do not have to be arranged over the entire length of the fixed secondary part.

In a further embodiment of the invention, the electrical machine can also be designed as a rotary permanent magnet synchronous motor, wherein the primary part is preferably designed as a fixed part, i. as a stator.

In the following description of further features and details of the invention in conjunction with the accompanying drawings using exemplary embodiments are explained in more detail. In this case, features and relationships described in individual variants can in principle be applied to all exemplary embodiments. In the drawings show: 1 shows a first embodiment of a tooth module according to the invention,

2 shows a second embodiment of a tooth module according to the invention and FIG. 3 shows a detail of a primary part according to the invention.

1 shows a first embodiment of a tooth module 1 according to the invention. The tooth module 1 has a coil 2 and a permanent magnet 3. The coil 2 is preferably designed as a tooth coil, also referred to as a pole coil. Furthermore, the tooth module 1 has the first laminated core 4 and the second laminated core 5. The first laminated core 4 carries the permanent magnet 3. The second laminated core 5 carries the coil. 2

The first laminated core 4 is according to the first embodiment of several parts, in particular two parts, constructed. The first laminated core 4 has two laminated core parts 4a, which are divided in a running direction 9 of a linear motor, not shown. Between the two laminated core parts 4a of the permanent magnet 3 is arranged. The permanent magnet 3 is also arranged perpendicular to the running direction 9. The permanent magnet 3 could also be arranged horizontally to the running direction 9 or in any other direction and shape in the tooth module 1 or in the first laminated core 4.

The first laminated core 4 could for example also be integrally formed. In a one-piece embodiment of the first laminated core 4, the two laminated core parts 4a could be connected to one another, for example by means of webs in the region of the end regions of the permanent magnet 3.

The second laminated core 5, which carries the coil 2, is constructed in two parts according to this embodiment. In this case, the two laminated core parts 5a of the second laminated core 5 are also divided perpendicular to the running direction 9 and arranged next to the laminated core parts 4a. In each case, a laminated core part 5a is arranged next to a laminated core part 4a. In particular a laminated core part 5a arranged to the left and right of a laminated core part 4a, so that the laminated core parts 5a 5a enclose the laminated core parts 4a from the outside.

There are the laminations of the laminated cores 4 and 5 are formed such that between these two laminated cores, a thermal contact resistance 6 is present. The thermal contact resistance 6 is realized by means of the air gap 7. The air gap 7 is formed as narrow as possible in order to enable thermal decoupling between coil 2 and permanent magnet 3 with the least possible disturbance of the magnetic fluxes.

Furthermore, the second laminated core 5 is formed so that it forms the yoke 13, wherein the laminated core 5 in the region of

Jochs 13 directly abuts in a portion of the laminated core parts 4a of the first laminated core 4. The yoke 13 of the second laminated core 5 forms a common conclusion with the laminated core parts 4a.

The coil 2 surrounds the second laminated core 5 and lies on two sides completely on the second laminated core 5. This ensures optimal heat transfer from the coil 2 to the second laminated core 5.

FIG. 2 shows a second embodiment of a tooth module 1 according to the invention. The tooth module 1 according to FIG. 2 essentially corresponds to the embodiment according to FIG. 1, wherein the second laminated core 5 with its two laminated core parts 5 a has a cooling element, which is designed as a cooling tube 8. The cooling tube 8 is provided for the flow through with a cooling medium, such as water, wherein the two cooling tubes 8 are connected to each other on the outer sides, for example, the front sides of the tooth module in the direction 9.

3 shows a detail of an electric machine 16 according to the invention with a primary part 14 according to the invention and a secondary part 15. The electric machine 16 is designed as a permanent-magnet synchronous linear motor. The primary part 14 has a plurality of tooth modules 1 according to the invention, which are arranged side by side in the running direction 9 of the primary part 14. The tooth modules 1 are arranged on a housing part 11. The housing part 11 has, at a predeterminable distance, sliding blocks 12, by means of which the toothed modules 1 are fastened to the housing part 11. The tooth module 1 is held by means of the sliding block 12, which engages in the fastening groove 10 of the tooth module 1. A tooth module 1 is inserted transversely to the direction of movement 9 of the primary part 14.

Furthermore, the tooth modules 1 are arranged such that in each case the second laminated cores 5 abut one another, so that optimum grooves for receiving the coils 2 are provided.

Furthermore, the tooth modules 1, the cooling tubes 8, which are connected to each other on the outer sides, so that a flow of a cooling medium can take place.

It is also possible to equip the housing part 11 with a further cooling circuit. The length of the primary part 14 can be made variable. It can toothed modules 1 are strung together to a desired length. In this case, the tooth modules 1 can be lined up in any desired number and direction, whereby a modular construction of a primary part 14 is provided.

Claims

claims

1. tooth module (1) for a primary part (14) of an electrical machine, wherein the tooth module (1) at least one coil (2) and a permanent magnet (3), characterized in that between the coil (2) and the permanent magnet (3 ) A thermal contact resistance (6) is formed.

2. tooth module (1) according to claim 1, characterized in that the tooth module (1) has a first laminated core (4) and a second laminated core (5), wherein on the first laminated core (4) of the permanent magnet (3) and on the second Laminated core (5) the coil (2) is arranged.

3. tooth module (1) according to claim 2, characterized in that the thermal Übergangsswi ^¬ resistance (6) between the first laminated core (4) and the two ^¬ th laminated core (5) is formed.

4. tooth module (1) according to claim 2 or 3, characterized in that the thermal contact resistance ^¬ (6) at least partially between the first and second laminated core (4, 5) is formed, wherein the thermal contact resistance (6) at least over a Ab ^¬ is formed, in which the permanent magnet (3) and the coil (2) are arranged opposite one another.

5. Tooth module (1) according to one of the preceding claims, characterized in that the thermal contact resistance (6) by means of an air gap (7) is formed.

6. tooth module (1) according to any one of the preceding claims, characterized in that the thermal contact resistance (6) is formed by means of a thermally and / or electrically insulating material.

7. tooth module (1) according to one of claims 2 to 6, since ^{¬ characterized in} that a heat ^¬ dissipation of the coil (2) to the second laminated core (5) he follows ^¬ .

8. tooth module (1) according to one of claims 2 to 7, since ^{¬ characterized in} that the second laminated core (5) has one or more cooling elements (8).

9. tooth module (1) according to claim 8, dadurchge ^¬ indicates that the cooling element (8) is designed as a cooling tube (9).

10. Tooth module (1) according to one of claims 2 to 9, d a c h e c e n e c e s that the second

Sheet metal package (5) is arranged such that the heat dissipation from the coil (2) via the second laminated core (5) to a Ge ^¬ housing the electric machine.

11. tooth module (1) according to any one of the preceding claims, characterized in that the Spu ^¬ le (2) is designed as a toothed coil.

12. tooth module (1) according to one of claims 2 to 11, d a c h e c e n e c e s that the first

Laminated core (4) on which the permanent magnet (3) is arranged, is constructed in two parts, wherein two laminated core parts (4a) perpendicular to a running direction (9) of the primary part are arranged side by side and wherein the permanent magnet (3) between the laminated core parts (4a) is arranged perpendicular to the running direction (9).

13. tooth module (1) according to one of claims 2 to 12, since ^{¬ characterized in} that the second laminated core (5) on which the coil (2) is arranged, is constructed in two parts, wherein two laminated core parts (5a) are arranged such in that, in addition to a laminated core part (4a) of the first laminated core (4), a laminated core part (5a) of the second laminated core (5) is arranged in the running direction (9).

14. Tooth module (1) according to one of the preceding claims, characterized in that the

Tooth module (1) has a fastening groove (10) for attaching the tooth module (1) on the housing of the primary part.

15 primary part (14) for an electrical machine, characterized in that the primary ^¬ part (14) has a plurality of tooth modules (1) according to any one of patent claims ^¬ 1 to 13.

16. Electrical machine with a primary part (14) and a secondary part (15), dadurchgekennzeich ^¬ net, that the primary part (14) a plurality of tooth modules (1) according to one of the claims 1 to 13.

17. Electrical machine according to claim 16, characterized in that the electrical machine as a permanent magnet synchronous linear motor (16) is formed, wherein the tooth modules (1) in a predeterminable An ^¬ number on the primary part (14) (in the running direction (9) of the linear motor 16) can be arranged side by side.

18. An electric machine according to claim 16, characterized in that the electric machine is designed as a rotary permanent magnet synchronous motor, the tooth modules (1) being arranged side by side in a predeterminable number on a stator designed as a primary part in the direction of rotation of a rotor.