WO2013156307A2

WO2013156307A2 - Molded part for pre-fastening a permanent magnet in a rotor or stator, fastening of the permanent magnet by means of a curable medium, and thermal protection of the permanent magnet during the fastening

Info

Publication number: WO2013156307A2
Application number: PCT/EP2013/057021
Authority: WO
Inventors: Juergen Koeninger; Mirco Beier; Stavroula Kritharidou; Stefan Stoermer; Thomas Heid; Otto Klementis; Ferenc Simon; Norbert Kupke; Bjoern Nommensen
Original assignee: Robert Bosch Gmbh
Priority date: 2012-04-19
Filing date: 2013-04-03
Publication date: 2013-10-24
Also published as: CN104471835B; DE102012206475A1; WO2013156307A3; CN104471835A

Abstract

The invention relates to a molded part for a rotor or stator of an electric machine, which molded part extends concentrically about an axis and has a face plate and at least one retaining strand, which is arranged on the face plate, wherein the retaining strand has a contact surface at the end of the retaining strand facing the face plate. The invention further relates to a rotor or stator for an electric machine having the molded part. The invention further relates to a rotor or stator for an electric machine, comprising a main body, which extends concentrically about an axis, and which comprises a permanent magnet, which is arranged in a cavity of the main body, wherein a retaining means is arranged on the permanent magnet, which retaining means has a retaining strand and a face plate, on which the retaining strand is arranged and which extends perpendicularly to the axial direction, wherein the retaining means is at least partially made from a curable medium. The invention further relates to methods for fastening a permanent magnet in such a rotor or stator.

Description

description

Molding for prefixing a permanent magnet in a rotor or stator, fixing the permanent magnet by means of a curable medium, and thermal protection of the permanent magnet during fixation

State of the art

The present invention relates to a molded part for a rotor or stator of an electric machine, which extends concentrically around an axis and has an end plate, and at least one holding strand, which is arranged on the end plate. The present invention further relates to a rotor or stator for an electric machine with the molding. The present invention further relates to a rotor or stator for an electric machine comprising a permanent magnet, which is arranged in a recess, wherein the retaining magnet, a holding means is arranged, which has a holding strand and an end plate. The present invention further relates to methods of attaching a permanent magnet in such a rotor or stator.

Electric machines are, for example, electric motors, starters, generators or auxiliary drives, for example adjusting drives for motor vehicles. In such electrical machines, it is known to provide the rotor or the stator for generating an electromagnetic field with permanent magnets. The attachment of permanent magnets in such permanent magnet-excited electrical machines depends on the geo- metric shape of the permanent magnets and the arrangement of the permanent magnets in or on the rotor or stator.

In the case of permanent magnets arranged in the shape of a spoke, it is known, for example, to provide clamping lugs on the main body of the rotor or stator with which the permanent magnets are radially clamped in their recess. The clamping is usually provided so that the permanent magnets are thereby simultaneously fixed axially and therefore can not be displaced along the axis. The permanent magnets are pressed into their recess and punctually very heavily loaded, which can lead to voltage peaks and damage, in particular a magnetic fracture or scratching of the magnetic surface and / or its coating both during assembly and under operating conditions of the electric machine. A damaged coating can no longer protect the permanent magnets against corrosion and / or the damage leads to an irregular magnetic field course and an increased leakage flux, so that the cogging torques and the torque ripple of the electrical machine are increased.

In addition, a high, in particular punctual, load of the permanent magnets lead to chipping and magnetic breakage. The chipping and debris can come off the permanent magnet and fall out of the recess, and then not only affect the performance of the electrical machine, but cause damage or even destruction of the electrical machine.

A likewise known fastening means of a spring element leads to such high mechanical loads.

The publication DE 10 2010 039 334.7 discloses a rotor or stator for an electric machine, which is used for fixing the permanent magnet in its recess has a separate elastic fixing means which is inserted after arranging the permanent magnet in the recess. Due to its elasticity, the fixing means has a defined spring behavior and / or mechanical clamping behavior. Thus, it is still sufficiently elastic after a distortion of the permanent magnet to compensate for component tolerances and the temperature behavior of the permanent magnet over the bandwidth of the temperatures occurring. The fixing means is made of a metal or a plastic.

It is also known to glue the permanent magnet in its recess. In these bonding methods, however, it is unknown whether enough adhesive is still arranged between the permanent magnet and the main body of the rotor or stator after the permanent magnet has been fitted into the recess. In addition, not all surface coatings with which the permanent magnets are coated, for example, to protect against corrosion, can be glued.

The document EP 1 921 734 A1 discloses a method for fixing the permanent magnets in the rotor, in which these are added powerless in a recess of the rotor and fixed by filling a plastic in order to reduce the risk of damage. In this method, it is possible that the permanent magnets are demagnetized due to the thermal stress during filling of the plastic and therefore flow losses.

Disclosure of the invention

The object of the present invention is to provide an electric machine and a method for producing the electrical machine, in which the risk of impairment of the operating behavior, or so even the damage or destruction of the electrical machine is reduced by magnetic fragments and chipping, in which the demagnetization risk for the permanent magnets is as low as possible, and which has the lowest possible torque ripple and / or small detent torque, the electric machine also inexpensive to produce and easy can be mounted. Another object of the invention is to provide a secure bonding method for bonding permanent magnets into a recess of a rotor or stator of an electrical machine, in particular for bonding permanent magnets into a recess of a spoke rotor.

The object is achieved with a molded part for a rotor or stator of an electrical machine, which extends concentrically around an axis and has an end plate, which is annular and arranged transversely to the axis, and at least one support strand, which at one of the end plate facing the end is arranged on this, and which extends in an axial direction of the axis, wherein the support strand has a contact surface, with which it is provided at least at its the end plate facing end for abutment with the permanent magnet, wherein the support strand two side legs and connecting the side legs Cross leg has.

In a preferred embodiment, which is referred to below as the first embodiment variant, the molding according to the invention is provided for prefixing the permanent magnet in a recess of a main body of a rotor or stator. In this first embodiment, the molding is prefabricated and is inserted before or after the insertion of the permanent magnet in the recess in this. The molded part of this embodiment is designed so that the permanent magnet, when it is joined in front of the molding in the body, is powerless in its recess fügbar. Powerless in the sense of the invention means that the permanent magnet is not clamped or pressed during assembly, but so inserted, in particular inserted or inserted, that he is not mechanically stressed as possible. As a result, it is gently inserted into the body, so that its surface and / or its coating are not damaged during assembly.

The molded part has an end plate which is provided transversely to the axis, and for arranging a retaining strand. In addition, it has the retaining strand, which reduces a free space of the recess between the permanent magnet and the base body. At least on its side facing the end plate, the support strand has a contact surface which pre-positions the permanent magnet radially, that is to say in a direction radiating from the axis. As a result, the permanent magnet is arranged on its opposite side of the molding substantially free of play in the recess.

According to the invention, the support strand also has two side legs and a side leg connecting the transverse leg. The side legs preferably extend in the axial and radial directions of the axle, with the transverse leg also preferably extending in the axial and tangential directions of the axle. In cross section of the support strand is therefore preferably formed U-shaped.

The molded part of the first embodiment variant, in particular the retaining strand of the molded part, is preferably elastic. As a result, it has a defined spring behavior and / or mechanical clamping behavior. It is particularly preferably elastic and / or plastically deformable. Preferably, after a plastic deformation, the molded part still has sufficient elasticity, by means of which it rests against a return deformed force and holds the permanent magnet with the restoring force in its position.

Further preferably, the support strand has recessed grooves relative to the contact surface, which extend in the axial direction. The grooves are preferably provided in the transverse leg. Also preferably, the support strand also has on its side facing away from the end plate on a free end on which a recessed relative to the contact surface countersink is provided. The grooves as well as the countersink surface enable the molded part to deform elastically and / or plastically upon insertion into the recess so that the contact surface bears against the permanent magnet. As a result, the permanent magnet is not only pre-positioned radially and / or axially in the recess, but in the area of the contact surface, the recess is also sealed.

Due to the radial pre-positioning of the permanent magnet, the molded part also causes the recess above the free end of the retaining strand forms a reservoir into which a curable medium is provided, which is provided for fixing the permanent magnet in its prepositioned position. The reservoir allows the introduction of a defined amount of the curable medium in the recess. Therefore, this first embodiment of the molding allows that the curable medium can be targeted zoomed to the permanent magnet zoom. Although the curable medium capped when filling into the recess, although in spaces between the molding and the permanent magnet and / or the main body of the rotor or stator. Since the molding reduces the free space of the recess between the permanent magnet and the main body, but the amount of curable in the interstices curable medium is low. In addition, the molding seals the recess in the area of the contact surface sealing. The curable medium thus does not flow out of the recess again. The term "sealing" is therefore to be understood in the sense of the invention, which prevents outflow of the selected hardenable medium during filling into the reservoir.

In order to be able to insert the molded part more easily into the recess, it is also preferred for the contact surface to run at least partially in the shape of a ramp. In one embodiment, the countersinking surface preferably extends along the support strand for this purpose. In this case, the transition between the contact surface and the countersink is preferably formed obliquely, so that it forms the ramp by the insertion of the permanent magnet in the recess between the support strand and the body, or the insertion of the molding in the recess between the permanent magnet and the Body is relieved. However, it is also preferred an embodiment in which the counterbore itself is formed obliquely relative to the contact surface and thus forms the ramp. In addition, also preferably the side legs are at least partially ramped and thus simplify the insertion of the molded part or the permanent magnet in the recess.

The molded part preferably has several holding strands distributed uniformly in the tangential direction. In this embodiment, the face plate is also provided for connecting the holding strands, so that not several holding strands are to be added individually in the body, but only a single molded part. It is preferred that the shaped part comprises a holding strand for each permanent magnet. In principle, however, an embodiment of the molding is conceivable in which a support strand is provided for a plurality of permanent magnets, when a plurality of permanent magnets are joined in the same recess of the main body of the rotor or stator. In a further preferred embodiment, which is referred to below as the second embodiment, the molding according to the invention for fixing the permanent magnet is provided in its recess of the main body of a rotor or stator. In this embodiment, the molding is formed by injecting or pouring a curable medium. This second embodiment also makes it possible to insert the permanent magnet powerless in its recess.

Also in this second embodiment, the molded part has an end plate which is provided transversely to the axis, and here for the axial fixation of the permanent magnet, as well as a support strand which extends in the axial direction. The face plate secures the permanent magnet in an axial direction, while the retaining strand limits movement of the permanent magnet in a radial direction. The attachment of the permanent magnet is based in this embodiment on a positive connection.

The support strand of the second embodiment also has two side legs and a transverse leg connecting the side legs, the side legs preferably extending in the axial and radial directions of the axis, and the transverse leg also preferably extending in the axial and tangential directions of the axis , In cross-section of the support strand of this embodiment is therefore also formed u-shaped.

The molded part of the second embodiment, in particular the retaining strand of the molded part, is preferably elastic, so that it has a defined spring behavior and / or mechanical clamping behavior. It is also particularly preferably elastic and / or plastically deformable. Preferably, after a plastic deformation, the molded part still has sufficient elasticity by which it can be deflected against a ne restoring force deformed and holds the permanent magnet with the restoring force in its position.

The molded part of this embodiment variant has the advantage that it holds the entire rotor or stator together, in particular in the case of a rotor or stator package made of lamellae.

Particularly preferably, the molding of the second embodiment for two end plates, which are arranged on both sides of the support strand. In a rotor or stator formed to reduce eddy current losses from a plurality of rotor or stator parts slightly twisted in the tangential direction, it is preferred that at least the shaped part of the outer rotor or stator parts forming the lateral surface of the rotor or stator have an end face. In this embodiment, the lamellae of a centrally located rotor or stator are held axially by its adjacent rotor or stator, or the molded part of all rotor or stator is integrally formed.

Also in this embodiment, it is preferred that the molded part evenly distributed in the tangential direction has a plurality of holding strands, preferably for each permanent magnet a holding strand. But here, too, an embodiment of the molding is preferred in which a support strand is provided for a plurality of permanent magnets, provided that the same recess of the base body is provided for the plurality of permanent magnets.

The object is further achieved with a rotor or stator for an electric machine, in particular a spoke rotor, which has a base body which extends concentrically about an axis, and which comprises a permanent magnet, which is arranged in a recess of the base body, wherein the rotor or Stator also has a includes molded part. The molded part preferably extends concentrically around the same axis. The contact surface of the molding is preferably provided on the side facing the permanent magnet side of the support strand. In the first embodiment, the permanent magnet is pre-positioned with the molding in the body. The contact surface is preferably applied to the permanent magnet. In the second embodiment, it is positively secured in the recess, wherein it is preferred that the contact surface rests against the permanent magnet at least during operation of the electric machine.

In a preferred embodiment, which further solves the problem, the rotor or stator has a concentric about an axis extending base body, and a permanent magnet, which is arranged in a recess of the base body, wherein on the permanent magnet, a holding means is arranged, which a support strand which extends in the axial direction in the recess, and which also has an end plate on which the support strand is arranged, and which extends transversely to the axial direction.

It is inventively provided that the holding means is at least partially made of a curable medium, in particular of a plastic or resin. As a result, the recess is at least partially filled with the curable medium.

A curable medium in the context of the invention is a material or a mixture of materials, which is added to the body, for example as granules or in liquid form, and only then hardens. In a preferred embodiment, the inventive molding of the first embodiment and the curable medium together form the retaining means. In this embodiment, it is preferable that the curable

Medium cohesively connects with the molding, the permanent magnet and the body. As a result, it ensures a permanent connection of the permanent magnet with the main body. Since the holding means rests with its contact surface of the holding strand and / or the curable medium at least partially flat against the permanent magnet, there is a flat contact area between the holding means and the permanent magnet, so that the surface pressure and the clamping force of the holding means spread over the permanent magnet and already With a low surface pressure a large clamping force is effected. Particularly preferably, the surface pressure runs continuously along the permanent magnet in the contact region. Most preferably, the surface pressure and / or the clamping force on the permanent magnet in the axial direction are constant.

Since the clamping force acts on these at least approximately distributed over the length of the permanent magnet, a relatively small surface pressure is sufficient. It is therefore preferred that the ratio of the spring stiffness to the contact surface is small. As a result, component tolerances only insignificantly affect the clamping force. In addition, the permanent magnet is thereby very gently clamped and its surface and / or coating neither damaged during assembly nor under operating conditions. Since the surface and / or coating of the permanent magnet is not damaged, the magnetic field in the rotor or stator runs evenly. In addition, the permanent magnet can be effectively protected against corrosion by the undamaged coating. The molded part of this embodiment is preferably formed from a plastic, in particular a monopox, an elastomer or a thermoplastic, and has an elasticity and / or plasticity. The curable medium is preferably formed from a resin or adhesive that cures upon contact with air and / or with metal contact, preferably a cast resin or an anaerobic adhesive. Only the arrangement of the molding for prefixing the permanent magnet allows the use of such a curable medium for fixing the permanent magnet.

The prefixing of the permanent magnet in the body with the help of the molding according to the invention also allows magnetic surfaces are used, on the one hand provide sufficient corrosion protection for the permanent magnet, but on the other hand, due to their nature have not sufficient protection against mechanical stresses. Such permanent magnets are relatively inexpensive to produce. The fixation of the permanent magnet over the life of the electric machine takes place in this embodiment of the rotor or stator ultimately on the curable medium and its cohesive connection with the permanent magnet, the molding and the body.

In a further preferred embodiment, the holding means is integrally formed from the curable medium. As a curable medium, a plastic is preferably used. In principle, a preparation of a resin, in particular a casting resin, conceivable. Most preferably, however, the holding means of this embodiment is formed from a thermoset or a thermoplastic. It is therefore non-magnetic, not electrically conductive and very inexpensive to produce. In this embodiment, it is further preferred that the holding means comprises two mutually parallel end plates which abut against opposite lateral surfaces of the rotor or stator, and which are interconnected by the support strand. The holding means is preferably produced by encapsulation or encapsulation of the permanent magnet prepositioned in the recess with the curable medium. In addition, it is preferred that the permanent magnet has an end face which is provided flush with the lateral surface of the rotor or stator. The permanent magnet is then bordered by the holding means through the end plates after curing of the hardenable medium. In this embodiment, the holding means preferably surrounds the permanent magnet in a form-fitting manner.

Since the end plates preferably abut against a lateral surface of the rotor or stator, they also fix the permanent magnet axially even if there is an air gap between the permanent magnet and the main body of the rotor or stator due to a relaxation of the plastic. Under operating conditions, relaxation of the plastic is also compensated by the centrifugal forces pushing the permanent magnet outwards.

In the case of a basic body produced as a disk pack, this embodiment of the rotor or stator has the advantage that the holding means holds the disk pack together, so that the disks can no longer move in the axial direction after arranging the clamping means, and therefore no longer spring against one another.

In a rotor or stator formed to reduce eddy current losses from a plurality of rotor or stator parts slightly twisted in a tangential direction to one another, it is preferred that at least the outer rotor or stator forming the lateral surface of the rotor or stator

Stator parts have a holding means with an end face. At this Guidance form, the lamellae of a rotor or stator on one side, where the holding means has no face plate, held axially by the adjacent rotor or stator. Or the holding means of all rotor or stator parts is integrally formed.

In a holding means produced in one piece from a hardenable medium, in a further embodiment it is preferred that a protective component is arranged between the holding means and the permanent magnet. The protective component is preferably made of a material with low thermal conductivity and low magnetic conductivity, in particular made of a plastic. Particularly preferably, the protective component is made of a thermoplastic or of a duroplastic.

Preferably, the protective member is placed in the slot prior to insertion of the permanent magnet. Depending on the method of attachment of the protective component to the permanent magnet, however, arranging the protective component in the recess is also possible after the permanent magnet has been arranged in its recess.

Particularly preferably, the protective component is glued to the permanent magnet, shrunk, molded or molded. In this case, injection molding or casting is very preferably carried out prior to arranging the permanent magnet in its recess, and also before magnetizing the permanent magnet in order to prevent demagnetization of the permanent magnet, since the permanent magnet is thermally stressed in this method. The protective component protects the permanent magnet during the encapsulation or encapsulation before the thermal load, in particular when using thermoplastic as a curable medium. In principle, as a protective component, a corrosion protection for the permanent magnet is conceivable, which has a sufficient thickness on its side facing the contact surface of the holding means side.

The face plate is preferably annular. In a preferred embodiment, it completely covers the end face of the permanent magnet. As a result, no chipping of the permanent magnet escape from the recess and lead to uneven running behavior or even damage to the electrical machine.

The following statements apply to all previously described embodiments of the rotor or stator.

The main body of the rotor or stator is preferably made as a disk set of a plurality of fins. However, the invention also includes a body made of a solid body. In addition, the invention also includes basic body, which are made of several in the axial direction one behind the other arranged basic body parts.

The object is also achieved with an electric machine with such a rotor or stator. An electric machine is, for example, an electric motor, an adjustment drive, in particular for motor vehicles, a generator or a starter. The object is likewise achieved with an electric motor, in particular a synchronous machine, which comprises such a rotor or stator. The object is further achieved with a hand tool with such an electric motor, for example with a drill, a jig saw or the like. The object is also achieved with an adjustment drive for a motor vehicle, in particular a steering drive, or with an adjustment drive for an electric bicycle, with such an electric motor. The object is further achieved with a method for fastening a permanent magnet in a rotor or stator of an electrical machine, wherein the rotor or stator has a base body with a recess for the permanent magnet, comprising the following steps:

Inserting the permanent magnet into the recess,

- Inserting a molding according to the invention of the first embodiment in the recess, so that the contact surface radially and / or axially prefixed the permanent magnet, and

- Fill a hardenable medium in the recess.

By the molding of the first embodiment of the permanent magnet is pre-positioned in the recess, that in the recess a reservoir between the permanent magnet and the main body of the rotor or stator or the molding remains. This allows a filling of a defined amount of the curable medium into the recess, so that the curable medium, although at least partially capillaries in intermediate spaces between the permanent magnet and the molding or between the body and the molding, but does not flow out of the recess. As the curable medium, a resin is preferably used. The positioning of the permanent magnet in the base body takes place in this process by the molding, the fixation of the permanent magnet is carried out by the curable medium, which preferably connects cohesively and positively with the body, the molding and the permanent magnet during curing.

The method has the advantage that the permanent magnet is powerless inserted into the recess, since the molding is particularly preferably inserted after the insertion of the permanent magnet in the recess. In addition, the surface of the molding is such that the permanent magnet is not damaged by the molded part, for example, scratched is. Farther allows only the use of the molding for sealing the recess, the use of such resins for bonding permanent magnets in the recess.

The object is further achieved with a method for fastening a permanent magnet in a rotor or stator of an electrical machine, wherein the rotor or stator has a base body with a recess for the permanent magnet, comprising the following steps:

Arranging a protective component on the permanent magnet,

- magnetizing the permanent magnet,

- Inserting the permanent magnet into the recess, and

- filling a curable medium in the recess,

wherein the protective member is at least partially disposed between the permanent magnet and the curable medium.

The protective component is preferably formed from a plastic having a low thermal conductivity and a low magnetic conductivity. It is arranged at least on all the curable medium-facing sides of the permanent magnet. Thus, it protects the permanent magnet during encapsulation or encapsulation with the curable medium from the resulting temperature stress. Because the Entwärmrichtung the injection molding compound is due to the low thermal conductivity of the

Protective device directed towards the tool and not towards the permanent magnet. The risk that the permanent magnet is at least partially demagnetized by too high a temperature load during the encapsulation or encapsulation is thereby considerably reduced.

Particularly preferably, the protective component is arranged in the recess before insertion of the permanent magnet. It is preferably formed from a sprayed frame, which is positioned on the magnet, or likewise preferably by a coating of the permanent magnets formed. It is particularly preferably adhered to the permanent magnet, molded, molded or shrunk. In this case, the permanent magnet can be protected only partially or on more than one side by the protective component, for example on 3 or 4 sides of the permanent magnet, depending on how the overmolding process is carried out. In a preferred embodiment, the protective component is arranged on the magnet before the magnetizing of the permanent magnet, so that the arrangement of the protective component can not lead to a Teilentmagnetisierung.

In the following the invention will be described with reference to figures. The figures are merely exemplary and do not limit the general idea of the invention.

1 shows in (a) a molded part according to the invention in a perspective view, and in (b) an enlarged detail of the molded part from (a),

FIG. 2 shows a rotor with the molded part from FIG. 1 in a perspective view, FIG.

3 shows a section through the rotor of FIG. 2 in the region of a contact surface of the molded part, FIG.

4 shows a section B-B through the rotor of FIG. 2,

5 shows in (a) a further embodiment of a molded part according to the invention in a perspective view, which forms a holding means for permanent magnets of a rotor formed entirely of a hardenable medium, and in (b) a section of the holding means from (a), Fig. 6 shows in (b) another completely made of a hardenable

Medium formed holding means for permanent magnets of a rotor in a perspective view, in (a) the rotor with a holding means of (b), and in (c) a section C-C through the rotor of (a),

7 shows in (a) a further section through a rotor with the holding means from FIG. 5, and in (b) a further section through a rotor with the holding means from FIG. 6, FIG.

Fig. 8 shows in (a) a section of the rotor of Fig. 7 (a),

and in (b) a section of a rotor with protective component, FIG. 9 shows in (a) - (d) respective permanent magnets with one or more protective components,

Fig. 10 shows in (a) and (b) two different embodiments for main bodies of a spoke rotor,

Fig. 11 shows a section through a rotor with a holding means, which is made in one piece from a curable medium, and Fig. 12 shows a section of a further embodiment of a rotor with a likewise integrally made of a curable medium holding means.

The molded part 1 of FIG. 1 extends concentrically about an axis 2 and has an end plate 1 1, which is annular and arranged transversely to the axis 2, and a plurality of retaining strands 12, which at the end plate 1 1 are arranged, and extend in an axial direction 21 of the axis 2. The holding strands 12 are uniformly distributed in a tangential direction 23 around the face plate 1 1 around. This molded part 1 is provided for pre-positioning of permanent magnets 4 in a recess 5 of a main body 35 of a rotor 3 of an electric machine (not shown) (see Fig. 2). It is therefore in this molding 1 to a molding 1 of the first embodiment. The number of holding strands 12 corresponds to the number of permanent magnets to be positioned before 4. The molded part 1 is elastic and / or plastic and made of a plastic.

The holding strands 12 each have two side legs 125 and a side leg 125 connecting transverse leg 126, wherein the side legs 125 in the axial direction 21 and a radial direction 22 to the axis 2 and the transverse leg 126 in the axial direction 21 and the tangential direction 23rd extend. The holding strands 12 are therefore formed approximately U-shaped in cross section.

At one of the end plate 1 1 facing the end 128, each of the holding strand 12 has a contact surface 122 which is provided for abutment with a permanent magnet 4 and disposed in an installed state of the molded part 1 in the rotor 3 on a permanent magnet 4 facing side 123 of the support strand 12 , With the contact surface 122, the permanent magnet 4 is pre-fixed in the radial direction 22 and possibly also in the axial direction 21 in the recess 5 (see Fig. 2). As a result, the permanent magnet 4 is in the installed state of the molded part 1 on a side facing away from the support strand 12 on the main body 35.

At its end 129 facing away from the end plate 1 1, each of the holding strands 12 has a free end 13, on which a countersink surface 120 which is recessed relative to the contact surface 122 is provided, which extends flat along its support strand 12. The countersink 120 allows an elastic beautiful and / or plastic deformation of the retaining strand 12 during insertion of the molded part 1 in the recess 5 of the rotor. 3

The sinking surface 120 is connected to the contact surface 122 via a ramp 1201, which is the insertion of the molded part 1 in the recess 5 of

Rotor 3 facilitates, in particular in already arranged in the recess 5 permanent magnet. 4

In addition, 12 grooves 121 are arranged on each of the holding strand, which extend in the axial direction 21, and here provided both on the permanent magnet 4 facing side 123 of each support strand 12, and on the side facing away from the permanent magnet 4 side 124 of each support strand 12 are. The grooves 121 are provided on the permanent magnet 4 facing side 123 of each retaining strand 12 recessed relative to the contact surface 122. They also allow an elastic and / or plastic deformation of the retaining strand 12 during insertion of the molded part 1 in the recess 5 of the rotor 3. In addition, allow the arranged on the permanent magnet 4 side 123 grooves 121 and an engagement of webs 351 1 (s. FIG. 2) of the base body 35 in the grooves 121, which are provided for collecting the useful magnetic flux.

At their end face 1 1 facing the end 128 of each support strand 12 and the side legs 125 are ramp-shaped to facilitate the introduction of the molded part 1 in the recess 5. In addition, the side legs 125 have there widenings 127, so that they rest in the installed state in this area sealingly on the base body 35.

At their end face 1 1 facing the end 128, the holding strands 12 are formed at least in a region of the contact surface 122 so corresponding to the shape of the base body 35 that they the recess 5 in 3, 4), which is filled into the recess 5 above the free end 13 of each of the retaining strands 12. This area is referred to below as sealing area 130.

Fig. 2 shows a rotor 3 with the molded part 1 of Fig. 1. The rotor 3 has a base body 35 which extends concentrically about the axis 2 and in which a plurality of recesses 5 are arranged, in which permanent magnets 4 are provided. The permanent magnets 4 are designed as flat magnets and are here arranged like a spike in the base body 35, so that they extend parallel to a fictitious plane (not shown) spanned in the radial 22 and the axial 21 direction. The rotor 3 shown here is therefore a spoke rotor. Between the recesses 5 and permanent magnets 4, the rotor 3 has rotor segments 30. On the side facing away from the axis 2 of the permanent magnet 4, the rotor segments 30 are connected by transverse webs 33 with each other. The transverse webs 33 are provided in a blade made of rotor 3 on at least some of the fins.

At the axis 2 facing side of the permanent magnets 4, the rotor segments 30 are connected by longitudinal webs 32 with a shaft portion 31 of the main body 35. The shaft region 31 has, in the center of the main body 3, a through-hole 34 for a shaft (not shown) extending along the axis 2.

Shown in Fig. 2, one of the end plate 1 1 of the molded part 1 facing away from lateral surface 351 of the rotor 3. In the recesses 5 between the permanent magnet 4 and the main body 35 of the rotor 3, therefore, the free ends 13 of the holding strands 12 are visible. The molded part 1 causes the permanent magnets 4 in the radial direction 22 in each case on its side facing away from the molded part 1 on the main body 35 create. Above the free end 13 of each retaining strand 12, the recess therefore forms a reservoir 9 into which a defined amount of the curable medium 6 can be filled. Here, the holding strands 12 are provided here so that even at the side facing away from the permanent magnet 4 side 124 of the holding strands 12 each free space for arranging the curable medium 6 is provided. The curable medium 6 therefore also chaplets into intermediate spaces (see FIG. 3) between the permanent magnets 4 and the retaining strands 12 of the molded part 1 holding them, as well as into intermediate spaces between the main body 35 and the retaining strands 12. This is facilitated by the grooves 121 extending in the axial direction 21. 3 shows a section AA through a rotor 3, in which the permanent magnets 4 are fixed by means of a holding means 60, which is formed from a molded part 1 according to FIG. 1 and a curable medium 6. FIG. 3 shows approximately the section labeled AA of FIG. 1 b. In the sectional view is that between the support strand 12 of the molding 1 and the permanent magnet 4 and between the support strand 12 of the

Shaped part 1 and the base body 35 arranged curable medium 6 shown schematically.

The molded part 1 and the curable medium 6 together form the holding means 60. In this case, the shaped part 1 is provided for pre-positioning of the permanent magnets 4 and for radial and optionally axial fixing of the permanent magnets 4 in their recess 5. The hardenable medium 6 preferably bonds to the molded part 1, the permanent magnet 4 and the main body 35 in a materially bonded manner and therefore fixes the permanent magnet 4 over the service life of the electrical machine in the main body 35. FIG. 4 shows a section BB through the rotor of FIG. 2. The reservoir 9 formed above the free end of the retaining strand is visible, into which the defined quantity of curable medium 6 can be filled.

The filling takes place in an insertion direction shown by an arrow 7. Here, the curable medium 6 is sufficiently thin during filling, so that it is distributed in the insertion direction 7 in the spaces between the molded part 1 and the permanent magnet 4 and the main body 35. In the sealing region 130, the contact surface 122, the spacers 127 and the end plate 1 1 prevent the hardenable medium 6 from escaping from the rotor 3. The grooves 121 and the countersink 120 assist and facilitate the distribution by being arranged so that they move hardenable medium 6 lead specifically to the permanent magnet 4 and the main body 35.

A caused by the support strand 12 clamping force on the permanent magnet 4 is represented by arrows 14.

Fig. 5 shows in (a) an integrally made of the curable medium 6 holding means 60 without rotor 3, and in (b) an enlargement of a support strand 602 of the holding means 60 on one of the end plate 601 of the holding means 60 side facing. This holding means 60 is an embodiment of a molded part 1 of the second embodiment variant.

Also, this holding means 60 has a plurality of uniformly distributed in the tangential direction 23 holding strands 602, which are each provided for a permanent magnet 4. 1, the holding strands 602 of this holding means 60 are U-shaped with two side limbs 6025 extending in the axial 21 and radial 22 directions, which are tangentially formed by an axial 21 and a radial direction 23 direction extending transverse leg 6026 are connected together.

On its side facing the axis, the holding means 60 have webs 6028 which engage in grooves (not shown) of the main body 35 (see FIGS. 6 a and c) and improve the adhesion of the holding means 60 to the main body 35.

The holding means 60 is formed by encapsulation or encapsulation of the permanent magnets 4 prepositioned in the rotor 3. It is made of a plastic, in particular a thermoset or a thermoplastic. FIGS. 5 a and b show the holding means 60 after curing without the main body 35 of the rotor 3 arranged around it and without the permanent magnets 4.

Fig. 6 shows in (a) a rotor with a holding means made in one piece from the hardenable medium according to (b). FIG. 6c shows the section C - C through the rotor of FIG. 6a. This holding means 60 is also an embodiment of a molded part 1 of the second embodiment variant. This holding means 60 is also formed by encapsulation or encapsulation of the permanent magnets 4 prepositioned in the rotor 3. It is also made of a plastic, in particular a thermoset or a thermoplastic. FIG. 6 b shows the holding means 60 after curing without the main body 35 of the rotor 3 arranged around it and without the permanent magnets 4.

This rotor 3 also has the rotor segments 30 interconnected by transverse webs 33 and the shaft region 31 with the through bore 34 arranged in the center of the rotor 3. Furthermore, the rotor segments 30 are connected to one another here by the longitudinal webs 32, which are shown in the illustrations shown here but not visible are. And in the recesses 5 of the main body 3 are formed here as flat magnets permanent magnets 4 are provided, which are arranged like a spoke.

In contrast to the retaining means 60 of FIG. 3 formed from the molded part 1 and the hardenable mass 6, the retaining means of FIGS. 5 and 6, however, have an end plate 601 at both ends 6028, 6029 of the retaining strand 602. The end plates 601 are in each case on an end face 40 of the permanent magnet 4 and a lateral surface 351 of the rotor 3, which are preferably arranged flush to each other, flat. Thereby, the holding means 60 of these embodiments holds the rotor 3 in and against the axial direction 21. This has the advantage that neither the permanent magnet 4, nor the fins of the rotor 3 after hardening of the holding means 60 can still move axially to each other.

The holding means 60 of FIG. 6b differs from that of FIG. 5a by higher end plates 601. This is shown in FIG. 7, which shows in (a) a section through a rotor 3 with the holding means 60 from FIG. 5a and in (b) a section through the rotor 3 with the holding means 60 from FIG. 6b.

Namely, a height 601 1 of the end plate 601 at its side facing the permanent magnet 4 side 6012 in the embodiment of Fig. 7b in contrast to the embodiment of Fig. 7a is higher than a height 401 of the permanent magnet 4. In the embodiment of Fig. 7b The front plate 601 therefore covers the end face 40 of the permanent magnet 4. Magnetic fragments which could form, for example, under operating conditions can therefore not fall out of the recess 5 in the rotor 3 of the embodiment of FIG. 7b. The end plates 601 can also be used for balancing the rotor 3 in this embodiment of the rotor 3.

For the integrally formed from a curable medium 6 molding or holding means 60 of FIG. 5-7 is preferably either a thermoplastic or a thermoset used.

A thermoplastic is usually present as granules. The granules are melted so that the molecules combine. Then, the pre-positioned in the recess 5 permanent magnet 4 is encapsulated with the molten thermoplastic. In contrast, a thermoset is present as a viscous material, ie in the liquid state. In order for the molecules to connect, the permanent magnet 4 prepositioned in the recess 5 must be encapsulated with heated thermoset. The thermal load of the permanent magnet when using a thermoset is therefore higher than when using a thermoplastic. In the formed of a thermoset retaining means 60 but a greater dimensional accuracy is possible. The holding means 60 formed from a thermoplastic, however, is more elastic.

FIG. 8 shows in (a) a further detail of a rotor 3 with the holding means 60 of the embodiment of FIG. 5a. Shown is the end face 40 of the permanent magnet 4 in the radial direction 22 only partially overlapping end plate 601 of the holding means 60th

FIG. 8b shows a detail of a rotor 3 with protective component 8. It can be seen here that a protective component 8 is arranged between the permanent magnet 4 and the holding strand 602 of the holding means 60. The protective component 8 has a low thermal conductivity and is formed, for example, from a plastic. It is arranged in the recess 5 on the permanent magnet 4 before the filling of the hardenable mass 6, preferably also before the magnetization of the permanent magnet 4, and protects it during the encapsulation or over-molding before the high temperature load. As a result, the risk of demagnetization of the permanent magnet 4 is greatly reduced.

FIG. 9 shows permanent magnets 4 with one or more protective components 8 arranged on its sides 41-44. The protective components 8 are formed from metal sheets.

10a and b show various embodiments of base bodies 35 for spoke rotors 3. In this case, the main body 35 shown in FIG. 10a corresponds to the main body 35 used in FIGS. 2 and 6a.

In the case of a retaining means 60 formed integrally from hardenable medium 6, however, a base body 35 of the embodiment of FIG. 10b can also be used. This main body 35 has in comparison to the main body 35 of FIG. 10a no shaft portion 31 and no shaft portion 31 with the rotor segments 30 connecting longitudinal webs 32. As a result, stray fluxes are avoided, which flow from the rotor segments 30 via the longitudinal webs 32 in the shaft member 31.

In the center of this base body 35, therefore, only a single recess 5, 34 is arranged, which is provided both for receiving the permanent magnet 4 and for receiving the shaft 20.

FIG. 11 shows a section through a rotor 3 with a main body 35 of the embodiment of FIG. 10b. Accordingly, the holding means 60 has only one holding strand 602 extending concentrically around the shaft 20. The end plates 601 of this holding means 60 are not visible in the sectional view. On the shaft 20 positive locking means 21 are provided which improve the torque transmission.

In the case of the rotor of FIG. 12, in each case positive locking means 301 are provided on the rotor segments 30, which improve the positive locking of the retaining strand 12 of the holding means 60 with the rotor segments 30. In addition, a sleeve 200 is provided between the shaft 20 and the holding means 60. Also, the sleeve 200 has positive locking means 201, which improve the positive connection to the holding means 60. By the positive locking means 201, 301, the torque transmission is also improved. The positive locking means 201, 301 are preferably T-shaped or dovetail-shaped.

In the spoke rotors 3 shown here, the permanent magnets 4 are magnetized in the tangential direction 23, so that magnetic poles N, S are formed between the permanent magnets 4 (see FIG. An integrally formed from hardenable medium 6 retaining means 60 is also suitable for rotors or stators with radially magnetized magnet 22 permanent magnet 4 (not shown), in which the useful flux leading magnetic poles N, S in the case of rotors on the shaft 20 facing away from the permanent magnets 4, and in the case of stators on the shaft 20 facing side of the permanent magnets 4 form.

Claims

claims

1 . Molded part (1, 60) for a rotor (3) or stator of an electrical machine, which concentrically extends about an axis (2) and an end plate (1 1, 601), which is annular and arranged transversely to the axis (2) is, as well as at least one holding strand (12, 602), which at one of the end plate (1 1, 601) facing the end (128, 6028) is arranged on this, and in an axial direction (21) of the axis (2) extends, wherein the support strand (12, 602) has a contact surface (122, 6022) which at least at its the end plate (1 1, 601) facing the end (128, 6028) for abutment with a permanent magnet (4) of the rotor (3 ) or stator is provided,

characterized in that

the retaining strand (12, 602) has two side legs (125, 6025) and a side leg (125, 6025) connecting transverse leg (126, 6026).

2. molding (1, 60) according to claim 1, characterized in that the transverse limb (126, 6026) relative to the contact surface (122, 6022) recessed grooves (121, 6021) extending in the axial direction (21, 6021 ).

3. Molding (1) according to one of the preceding claims, characterized in that the holding bar (12) on one of the end plate (1 1) facing away from the end (129) has a free end (13) on which a relative to the contact surface (122 ) countersunk sinking surface (120) is provided.

4. molding (1) according to one of the preceding claims, characterized in that the contact surface (122) extends at least partially ramped.

5. molded part (1) according to one of claims 1 - 2, characterized in that it comprises two end plates (601, 603) which are arranged on both sides of the support strand (602).

6. rotor (3) or stator for an electrical machine, in particular

Spoke rotor which concentrically extends about an axis (2) and which comprises a permanent magnet (4) which is arranged in a recess (5) of the rotor (3) or stator, wherein the rotor (3) or stator also a molding (1, 60) according to one of the preceding claims.

7. rotor (2) or stator for an electric machine, in particular according to claim 6, which has a base body (35) concentrically extending about an axis (2) in its axial direction (21), and a permanent magnet ( 4), which is arranged in a recess (5) of the main body (35), wherein in the recess (5) a holding means (60) is arranged, which has a holding strand (12, 602) which extends in the axial direction (21) into the recess (5) extends into it, and an end plate (1 1, 601) on which the support strand (12, 602) is arranged, and which extends transversely to the axial direction (21)

characterized in that

the holding means (60) is at least partially formed from a hardenable medium (6, 60), in particular from a plastic or resin.

8. rotor (3) or stator according to claim 7, characterized in that the holding means (60) from a molded part (1) according to one of claims 1-4 and the curable medium (6) is formed.

9. rotor (3) or stator for an electric machine according to claim 7, characterized in that the holding means (60) is integrally formed from the curable medium.

10. rotor (3) or stator for an electric machine according to claim 9, characterized in that between the holding means (60) and the permanent magnet (4) a protective component (8) is arranged.

1 1. Rotor (3) or stator for an electric machine according to claim 10, characterized in that the protective component (8) is made of a material with low thermal conductivity, in particular of a plastic.

12. rotor (3) or stator for an electric machine according to any one of claims 9 - 1 1, characterized in that the holding means (60) rests positively on the permanent magnet (4) or on the protective component (8).

13. Rotor (3) or stator according to one of claims 6 - 1 1, characterized in that the end plate (12, 602) rests against a transversely to the axial direction (21) arranged end face (40) of the permanent magnet (4).

14. rotor (3) or stator according to one of claims 6 - 12, characterized in that the end plate (12, 602) completely covers the end face (40) of the permanent magnet (4).

15. A method for fixing a permanent magnet (4) in a rotor (3) or stator of an electric machine, wherein the rotor (3) or stator has a base body (35) with a recess (5) for the permanent magnet (4), with following steps:

Inserting the permanent magnet (4) into the recess (5),

• insertion of a molded part (1) according to one of claims 1 - 4 in the recess (5), so that the contact surface (122) of the molded part (1) the permanent magnet (4) radially prefixed, and

• filling a curable medium (6) in the recess (5).

16. A method for fixing a permanent magnet (4) in a rotor (3) or stator of an electric machine, wherein the rotor (3) or stator has a base body (35) with a recess (5) for the permanent magnet (4), with following steps:

Arranging a protective component (8) on the permanent magnet (4),

Magnetizing the permanent magnet,

• Inserting the permanent magnet (4) into the recess (5), and

• filling a curable medium (6) in the recess (5), so that the protective component (8) between the permanent magnet (4) and the curable medium (6) is arranged.