DE102019205101A1 - Method for manufacturing an electromechanical component - Google Patents

Abstract

The invention relates to a method for producing an electromechanical component (2) for an electric machine from a laminated core which has several pole teeth (4), a groove (12) extending between each two directly adjacent pole teeth (4), the grooves ( 12) and pole teeth (4) each have a surface which, in an injection molding process, are encapsulated with plastic at least within the grooves (12), an insulating layer (14) with grooves (16) on at least one surface of each groove (12) Reception of wire is provided.

Description

The invention relates to a method for producing an electromechanical component, for example a rotor or stator, for an electric machine and an electromechanical component for an electric machine.

A rotor of an electric motor has a laminated core which is arranged on a shaft of the rotor. The laminated core comprises grooves for receiving wires, the wires having to be insulated from the laminated core within the grooves.

For example, copper windings are wrapped around a laminated core. To prevent the wires from rubbing, two plastic washers are used axially. As slot base insulation, d. H. As a rule, standard insulating paper with aramid fibers is used to insulate the wires from the earthed core.

A method and an injection molding tool for producing a rotor for an electric motor are in the document DE 36 13 842 A1 described.

The pamphlet DE 10 2011 090 081 A1 describes a disk pack for an electrical machine.

A method for producing a positively balanced internal rotor for use in an electric motor is disclosed in the document DE 10 2016 121 766 A1 known.

A stator for a mains-operated EC motor is from the publication DE 10 2016 121 856 A1 known.

The publication describes another stator for an electric motor DE 20 2017 100 616 U1 .

Against this background, it was an object to arrange wires for a winding or a coil of an electromechanical component for an electrical machine in slots of this component in an electrically insulated manner.

This object is achieved by a method and a component with the features of the independent claims. Embodiments of the method and the component emerge from the dependent claims.

The method according to the invention is provided for producing an electromechanical component for an electric machine from an axially symmetrical or rotationally symmetrical laminated core, for example, which has several pole teeth, a groove usually extending axially between each two immediately adjacent pole teeth. The grooves and pole teeth each have a surface which, in an injection molding process, is encapsulated with plastic, for example coated, at least within the grooves, the plastic being applied to the laminated core at least within the grooves. A respective groove can be at least regionally, i. H. For example, at least in a groove base or completely encapsulated with plastic. In this case, an insulation layer with grooves for receiving wire is provided at least on one surface of a respective groove, the grooves being introduced or molded into the insulation layer during the injection molding process. The groove base of a respective groove, for example, is limited by two lateral inner walls of the groove, depending on the definition.

In the method, in addition to the groove base, at least one surface of the laminated core formed as the inner wall of each or one groove in the injection molding process is encapsulated with plastic, for example coated, with one in each case in the insulating layer made of plastic on or on the inner wall Groove, for example, axially oriented grooves are introduced or formed. The groove base of a respective groove is limited, depending on the definition, by two lateral inner walls of the groove.

Furthermore, it is also possible for a surface of the laminated core formed as the outer wall of each or one pole tooth to be encapsulated with plastic during the injection molding process, for example coated, with a respective pole tooth in the insulation layer made of plastic that is applied on or on the outer wall in the circumferential direction or in the angular direction or angular and / or tangentially oriented grooves are introduced or formed. It is possible that an inner wall of a groove and an outer wall of a pole tooth, the groove being arranged between and / or delimited by two immediately adjacent pole teeth, are at least partially identical.

Depending on the definition, an axially oriented outer wall of a pole tooth corresponds to a lateral inner wall of a groove; an outer wall of a pole tooth oriented in the circumferential direction or angularly and / or tangentially differs from this. The direction of rotation corresponds to a direction of a movement of a point of the laminated core, for example a point on the outer wall of a respective pole tooth when the laminated core rotates about the axis. This direction of rotation can, for example, be circular and / or curved.

In the method, wire is arranged in the grooves and wound around the pole teeth, a section of the wire being arranged in each groove, a layer of wire being formed within each groove and / or around a respective pole tooth, in each case a section of the wire is passed through each groove.

In the process, the laminated core is initially arranged between two star disks, with surfaces of the star disks also being able to be overmolded with plastic in the injection molding process.

In an embodiment of the method, an injection mold is used in which the laminated core is optionally arranged with the star disks, the injection mold having a negative mold formed from several mold cores for the plastic to be applied, which are shaped negatively or inversely, with one mold core of the negative mold in each case is arranged in a groove, wherein a respective mold core, for example. Relative to a groove in which it is arranged, is negatively or inversely shaped. In addition, the injection mold can have two covers as further negative molds, one cover being arranged axially on the laminated core and possibly a respective star washer and enclosing an outer wall oriented tangentially or in the circumferential direction of a respective pole tooth. In addition, it is possible that each mold core touches a section of each cover, with all mold cores and the two covers each forming a cavity which each completely encloses an outer wall of a pole tooth. On an outer wall, outer side or outer surface of a respective mold core, opposing grooves are arranged as negative molds for the grooves, which are introduced into the insulation layer during the injection molding process.

In the process, the plastic is injected into a cavity between the inner wall of a respective groove and the respective mold core of the negative mold. Accordingly, plastic is also injected into the cavity between the outer wall of one pole tooth and one mold core and one cover.

In the method, both an electromechanical component of the electric machine designed as a rotor and also as a stator can be produced.

The component according to the invention for an electric machine has, for example, an axially symmetrical or rotationally symmetrical laminated core with several pole teeth, a groove usually extending axially between each two directly adjacent pole teeth, the grooves and pole teeth each having a surface that is at least within the grooves are partially encapsulated with plastic, for example coated, with an insulation layer with grooves for receiving wire being arranged on at least one surface of each groove, the grooves being introduced or molded into the insulation layer during the injection molding process.

With the method it is possible to implement a plastic encapsulation as slot base insulation with integrated wire guide for a rotor of an externally excited synchronous machine, with the slot base or slot base in the groove, e.g. as part of the inner wall of the groove, of the laminated core for the rotor under implementation The plastic coating is coated and thus electrically isolated, the grooves being applied in or on the groove base.

Using the plastic encapsulation, the radial and axial insulation of the at least one wire, for example made of copper, can be realized in one cast. At the same time, the grooves or grooves or relations can be implemented as guides for the at least one wire with the injection mold. With the additional use of a fast winding technology, for example through flyer winding or needle winding, at least one neat and guided winding can be built up from the at least one wire.

One advantage of the method presented is that the insulation provided can be implemented quickly and reliably in one pour. The grooves or grooves or relations additionally provided as part of the method facilitate the winding of the component, for example designed as a rotor. Thermal conductivity can be controlled with the help of a material and is, for example, a factor of three better than that of a standard insulating paper. A thermoplastic or a flowable synthetic resin, for example, can be used as the material, which can additionally have a filler and / or a reinforcement, for example glass fibers.

In the process, the laminated core including axial star disks is placed in an injection mold and overmolded.

The plastic encapsulation is provided as slot base insulation with integrated wire guide for the rotor of an externally excited electric machine, for example a synchronous machine.

The component of the electrical machine, for example designed as a rotor, comprises a cylinder-like laminated core made of a plurality of star disks, the laminated core having axially extending grooves for inserting wire windings and / or Has conductor windings, the grooves having on their surfaces and / or inner walls an electrically profiled insulation layer made of a plastic that is applied by means of the injection molding process. At least one star disk can also have an insulating layer made of plastic that is applied by means of an injection molding process. In one embodiment of the method for producing the component provided, for example, as a rotor, a cylinder-like laminated core is provided from a multiplicity of star disks. The laminated core is then placed in an injection mold provided for this purpose. The laminated core is at least partially encapsulated with the plastic. The grooves are additionally injected into the groove base of a respective groove.

The component presented can, for example, be used as a rotor for an externally excited synchronous machine, which generates a magnetic field externally excited by means of copper windings.

With regard to high power densities of the electric machine when used in the automotive sector, for example for driving a vehicle, particularly high speeds, for example 18,000 to 20,000 revolutions / minute, are aimed for. For this reason, axial star washers made of steel are used to axially press the laminated core between them. These electrically conductive axial star disks are also insulated in the plastic encapsulation process.

The method differs from a procedure in which only coatings are provided, especially since coatings of this type have proven to be unsuitable because they tear open due to the different coefficients of expansion and no process-reliable thicknesses can be achieved.

With the presented method, in comparison to known coating methods, guides for windings or coils, for example made of copper, can be realized that are used for e.g. B. orthocyclic windings are important or essential, since a high copper fill factor can be provided. When producing an orthocyclic winding, the wire is alternately wound clockwise and counterclockwise around the pole teeth, in particular alternately around two directly adjacent pole teeth.

It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention.

• 1 zeigt in schematischer Darstellung eine erste Ausführungsform des erfindungsgemäßen elektromechanischen Bauteils sowie ein Detail dieses elektromechanischen Bauteils.
• 2 zeigt in schematischer Darstellung Details einer Spritzgussform, die zum Herstellen einer zweiten Ausführungsform des erfindungsgemäßen elektromechanischen Bauteils verwendet wird.

The invention is shown schematically on the basis of embodiments in the drawings and is described schematically and in detail with reference to the drawings.

• 1 shows a schematic representation of a first embodiment of the electromechanical component according to the invention and a detail of this electromechanical component.
• 2 shows a schematic representation of details of an injection mold which is used to produce a second embodiment of the electromechanical component according to the invention.

The figures are described in a coherent and comprehensive manner, the same components are assigned the same reference numbers.

In the 1a schematically shown first embodiment of the electromechanical component according to the invention 2 is designed for an electric machine. Details of this electromechanical component 2 are in 1b shown schematically.

This component includes 2 here a total of six pole teeth 4th . All pole teeth are here 4th formed from a laminated core. At one axial end of this laminated core there is a star washer 6th arranged. Furthermore, the component 2 three wire guide modules 8th on that between a central axis of the component 2 and the pole teeth 4th are arranged. In addition, each pole tooth has 4th a cover module on the outside 10 on. In addition, there is between two immediately adjacent pole teeth 4th one groove each 12 arranged. By definition, it is provided here that each pole tooth 4th has an outer wall with a surface. Furthermore, each groove 12 between two pole teeth 4th corresponding to an inner wall with a surface.

In the embodiment of the method according to the invention, at least the inner wall is in each case one groove 12 encapsulated with plastic and thus coated, with at least one groove on the inner wall 12 an insulation layer 14th provided. In addition, each pole tooth is also on the outer wall 4th an insulation layer in the injection molding process 14th upset. This also includes the insulation layer 14th additional grooves 16 brought in. These grooves 16 are designed to receive wire, which continues to be around the pole teeth 4th wrapped and through the grooves 12 is guided, the wire in particular in grooves 16 is performed, which at a groove bottom of a respective groove 12 are arranged.

It is provided here that every pole tooth 4th within the scope of usual manufacturing tolerances a largely cuboid body or a Has body with a largely rectangular base with rounded corners or edges. There are two first, here longer sides of each pole tooth 4th or the body of the pole tooth 4th oriented axially to the central axis. Two second, here shorter sides of the respective pole tooth 4th or the body of the pole tooth 4th are here curved and / or bent and oriented perpendicular to the first sides, depending on the definition, tangentially and / or in the circumferential direction or angularly to the central axis. When overmolding the mentioned sides of a respective pole tooth 4th are in the provided insulation layer 14th the grooves 16 introduced or inserted, each with a section of a groove 16 the pole tooth 4th or enclosing both first and second sides, with grooves 16 axially oriented on the first sides and grooves 16 on the second pages, depending on the definition, can be oriented in the direction of rotation and / or tangentially.

2a shows a schematic representation of six mold cores 20th and a shell 22nd an injection mold 24 , which is used when carrying out an embodiment of the method according to the invention for producing a second embodiment of the component according to the invention, in a schematic representation. Furthermore shows 2 B a lid 26th for this injection mold. It shows 2a that each mold core 20th is designed as a counterpart or negative shape of a groove of a component to be manufactured and here has a largely cuboid base body, the largely square base of which is curved like a section of a circular ring. Thus, each base area has a respective mold core 20th an inner curved long side 28 and an outer curved long side 30th , furthermore has a base area of a respective mold core 20th two straight broadsides 32 on. On each inner long side 28 and every broadside 32 are counter grooves 34 molded. The case 22nd the injection mold 24 has a cylindrical inner wall 36 on. How 2 B shows, has the lid 26th a circular ring section 38 on, which in turn has six blank sections 40 and six mold sections 42 having, which extends along the circular ring section 38 alternate in one direction of rotation. It is provided here that on one surface of each mold section 42 also counter grooves 34 are arranged.

To manufacture the component, it is initially provided that in each groove in the axial direction of a sheet metal core, as a blank, there is a respective mandrel 20th is placed, each mandrel 20th a respective groove except for a cavity between the inner wall of the respective groove and an outer wall of an inner longitudinal side 28 of the mold core 20th , and between a respective broadside 32 of the mold core 28 and fills the inner wall of the respective groove. It is also provided that the laminated core is also in the envelope 22nd arranged and thus from the inner wall 36 is enclosed. In the process, a cover is also placed on each axial end of the laminated core 26th arranged, here in each case a mold section 42 is arranged on a pole tooth of the laminated core. One blank section each 40 is on each one groove and thus on each mold core 20th arranged, it being possible that in each case one end of a mold core 20th a blank section 40 touched flush. Overall, an inner wall of a respective groove is made up of the two broad sides 32 and an inner long side 28 a mandrel inserted therein 20th enclosed. An axially oriented outer wall of a respective pole tooth of a respective broad side is also corresponding 32 a mandrel 20th enclosed. Correspondingly, an outer wall oriented tangentially or in the circumferential direction of each pole tooth is also formed by a shaped section 42 a lid 26th enclosed.

In the injection molding process, the now between the laminated core and the mold cores continues 20th , as well as the lids 26th provided cavities injection-molded plastic, which forms an insulation layer on each outer wall of a pole tooth and thus also on each inner wall of a slot, which due to the countergrooves 34 on the mold cores 20th and the lids 26th which has grooves for receiving wire. After hardening of the plastic or the insulation layer and removal of the embodiment of the component that is or has been formed from the plastic-coated laminated core, wire is placed in the grooves provided within the insulation layer on the inner walls of the grooves and the outer walls of the pole teeth.

List of reference symbols

2

Component

4th

Pole tooth

6th

Star disc

8th

Wire guide module

10

cover

12

Groove

14th

Insulation layer

16

groove

20th

Mold core

22nd

Shell

24

Injection mold

26th

cover

28, 30

Long side

32

Broadside

34

Counter grooves

36

Inner wall

38

Annulus section

40

Blank section

42

Mold sections

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 3613842 A1 [0004]
• DE 102011090081 A1 [0005]
• DE 102016121766 A1 [0006]
• DE 102016121856 A1 [0007]
• DE 202017100616 U1 [0008]

Claims (8)

A method for producing an electromechanical component (2) for an electrical machine from a laminated core which has several pole teeth (4), a groove (12) extending between each two immediately adjacent pole teeth (4), the grooves (12) and pole teeth (4) each have a surface which, in an injection molding process, are encapsulated with plastic in areas at least within the grooves (12), an insulation layer (14) with grooves (16) for receiving wire on at least one surface of each groove (12) provided. Procedure according to Claim 1 , in which a surface of the laminated core formed as the inner wall of a groove (12) is overmolded with plastic during the injection molding process, with axially oriented grooves (16) being made in the plastic insulating layer (14). Procedure according to Claim 1 or 2 , in which a surface of the laminated core formed as the outer wall of each pole tooth (4) is encapsulated with plastic during the injection molding process, with grooves (16) oriented in the circumferential direction and / or tangentially being introduced into the plastic insulation layer (14). Method according to one of the preceding claims, in which wire is arranged in the grooves (12) and wound around the pole teeth (4), a section of the wire being arranged in a respective groove (16). Method according to one of the preceding claims, in which the laminated core is initially arranged between two star disks (6), surfaces of the star disks (6) also being overmolded with plastic during the injection molding process. Method according to one of the preceding claims, in which an injection mold (24) is used, in which the laminated core is arranged, the injection mold having a negative mold formed from several mold cores (20) for the plastic to be overmolded, one mold core (20) in each case. the negative mold is arranged in a groove (12), the plastic being injected into a cavity between the inner wall of a respective groove (12) and the respective mold core (20) of the negative mold. Method according to one of the preceding claims, with which an electromechanical component (2) of the electric machine designed as a rotor or as a stator is produced. Component for an electric machine, which has a laminated core with several pole teeth (4), a groove (12) extending between each two immediately adjacent pole teeth (4), the grooves (12) and pole teeth (4) each having a surface, which is overmolded with plastic at least within the grooves (12) by an injection molding process, an insulation layer (14) with grooves (16) for receiving wire being arranged on at least one surface of each groove (12).

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