WO2020119846A1

WO2020119846A1 - Cage for the relative positioning of magnetic bodies on a laminated core of an electric machine

Info

Publication number: WO2020119846A1
Application number: PCT/DE2019/100956
Authority: WO
Inventors: Markus Dietrich; Christian Brunner
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2018-12-12
Filing date: 2019-11-06
Publication date: 2020-06-18
Also published as: DE102018131847A1

Abstract

The invention relates to a cage (1) for the relative positioning of magnetic bodies on a laminated core or on a solid material component of an electric machine, having: a hollow-cylindrical main body (2) and at least one holder (3) for a magnetic body (11) . The invention further relates to a rotor (10) of an electric machine having a cage (1), and a method for mounting a rotor of an electric machine.

Description

Cage for the relative positioning of magnetic bodies on a laminated core of an electrical machine

The invention relates to a cage for the relative positioning of magnetic bodies on a laminated core or on a solid material component of an electrical machine, egg NEN rotor of an electrical machine with a cage and a method for mounting a rotor of an electrical machine.

In known rotors of electrical machines, there is the problem of the positioning of the magnets with each assembly of a rotor for an electric motor or for an electrical machine with surface magnets.

Good positioning is necessary to ensure that the magnetic flux across the rotor circumference is as uniform as possible.

In order to achieve this, it is described, for example, in the publication US Pat. No. 4,954,736 A, to provide a sheet metal guide or metal webs between the magnets and additionally to fill the magnets with plastic.

The problem in solving, such as B. described in US 4,954,736 A, is that the positioning during the injection molding process, in which the magnets are connected to the rotor, is very complex.

Furthermore, the metal webs, between which the magnets are arranged, create magnetic short circuits, as a result of which the magnetic flux in the air gap between the rotor and stator decreases and the motor or the electrical machine has less power.

Furthermore, it is known that in the case of wet-running rotors with a non-circular or non-smooth or non-continuous, flush surface or surface which comprises a cavity, a so-called pump effect occurs, as a result of which the power of the motor or the electrical one Machine is reduced and the magnets can be damaged.

Thus, when assembling a rotor with permanent magnets, it is also important to ensure that the magnets are well positioned with respect to one another. It is therefore an object of the present invention to provide a device and a method with which or with which magnets can be easily positioned with respect to one another, preferably a magnetic short circuit between magnets can be avoided, as a result of which the performance of an electrical machine can be increased , and preferably also a round or smooth surface can be afforded to avoid pumping effects or cavities, whereby a higher power density can be achieved.

This object is achieved by the features of the independent Pa tent Claims. Further advantageous developments are the subject of the subclaims.

According to the invention, in a first aspect of the present invention, a cage for the relative positioning of magnetic bodies on a laminated core or on a solid material component of an electrical machine comprises a hollow cylindrical base body.

The cage, in particular its hollow cylindrical base body, preferably comprises at least one receptacle for a magnetic body. As a result, a magnet or a magnetic body can be optimally positioned relative to the cage or its hollow cylindrical base body, which also enables an optimal positioning of the magnetic body on a laminated core of a rotor or on a solid material component of a rotor.

Furthermore, it is preferred that the at least one receptacle at least partially penetrates the cylinder wall of the hollow cylindrical base body, in particular penetrates completely continuously, in order to form a passage from the outside inwards. It is thus possible for a magnet or a magnetic body to make direct contact with a laminated core of a rotor of an electrical machine or with a solid material component of a rotor of an electrical machine.

The cage preferably has a plastic material.

It is also favorable if the hollow cylindrical base body comprises a central part along its height, which is arranged between two axial end faces arranged opposite one another. Advantageously, at least one axial end face can be releasably attached to the central part in order to provide axial access to the at least one receptacle. Axial insertion of a magnetic body into a receptacle is thus possible.

It is also advantageous if an axial end face is circular.

It can also be provided that the at least one receptacle laterally comprises at least one insertion bevel which guides a magnetic body that can be inserted therein to its intended position relative to the hollow cylindrical base body.

Conveniently, the insertion bevel extends across the entire thickness of the cylinder wall of the hollow cylindrical base body.

It is also favorable if the insertion bevel is wedge-shaped.

The at least one receptacle preferably comprises two insertion bevels which are arranged opposite one another. This ensures optimal guidance of a magnetic body in its correct position relative to the cage or to its hollow cylindrical base body.

Two insertion bevels are preferably designed such that they taper in a wedge shape in the radial direction, in particular inwards in the radial direction, so that the at least one receptacle tapers inwards in the radial direction.

Alternatively, it is advantageous if two insertion bevels are designed such that they taper in a wedge shape in the radial direction, in particular outwards in the radial direction, so that the at least one receptacle tapers outwards in the radial direction.

It is further preferred that the at least one receptacle is polygonal, in particular rectangular, in the surface of the hollow cylindrical receptacle.

The at least one receptacle preferably comprises four sides, an insertion bevel being formed on at least one side.

Furthermore, it is advantageous if the at least one receptacle comprises four sides, an insertion bevel being formed on each side.

Advantageously, two sides of the at least one receptacle are arranged opposite each other. It is also expedient if the sides of the at least one receptacle have a different length, the preferably shorter sides of the at least one receptacle being arranged at the axial ends of the cage.

The relatively longer sides of the at least one receptacle preferably extend from an axial end face of the hollow cylindrical base body to the opposite axial end face thereof.

A second aspect of the present invention includes a rotor of an electrical machine.

It is expressly pointed out that the features of the cage, as mentioned under the first aspect, can be used individually or in combination with one another in the rotor.

In other words, the features relating to the cage mentioned above under the first aspect of the invention can also be combined with further features under the second aspect of the invention.

A rotor of an electrical machine preferably comprises:

- a cage according to the first aspect,

- a laminated core to avoid eddy currents or a solid material component made of solid material,

- Wherein the cage is arranged on the outside on the laminated core or the solid material component, in particular is attached to the laminated core or on the solid material construction part.

Furthermore, it is preferred that the cage and the laminated core are designed in such a way that they have a transition or press fit. Instead of the laminated core, the cage and the solid material component can also be formed from one another in such a way that they have a transition or press fit.

It can further be provided that a magnetic body is arranged in the at least one receptacle, in particular in a form-fitting manner.

The at least one receptacle and the magnetic body are preferably geometrically matched to one another in such a way that the cage clamps a magnetic body in the at least one receptacle in order to secure the magnetic body in the receptacle for a fastening. conditions, in particular for gluing with an adhesive, to be centered and temporarily fixed, in particular until the adhesive has hardened.

Furthermore, it is advantageous if the cage forms a continuous surface together with a magnetic body as the outside.

Advantageously, the cage forms a continuous, flush surface together with a magnetic body on the outside of the cage, as a result of which a cavity and a pump effect during operation of the rotor can be avoided.

In other words, the surface, which is formed on the outside by a magnetic body and the cage, is preferably round or smooth or continuous, flush, so that the outside of the rotor, for. B. no cavity is formed and a so-called pumping effect is avoided.

In other words, it is advantageous if the cage forms a hollow cylinder on the outside together with a magnetic body or a plurality of magnetic bodies, which acts as if it were made from one piece.

A shaft is advantageously connected to the laminated core or to the solid material component.

A third aspect of the present invention includes a method for assembling a rotor of an electrical machine.

It is expressly pointed out that the features of the cage, as mentioned in the first aspect, can be used individually or in combination with one another in the method for mounting a rotor of an electrical machine.

Furthermore, it is pointed out that the features of the rotor, as mentioned under the second aspect, can be used individually or in combination with one another in the method for assembling a rotor of an electrical machine.

In other words, the features mentioned above under the first aspect of the invention relating to the cage and the features mentioned above under the second aspect of the invention relating to the rotor can also be combined here with further features under the third aspect of the invention. The method according to the invention for assembling a rotor of an electrical machine preferably comprises the following steps.

Advantageously, a step comprises creating a rotor according to the second aspect.

The laminated core or the solid material component is preferably joined to the shaft when it is being created.

Furthermore, the cage and the laminated core or the solid material component are advantageously aligned coaxially and axially displaced relative to one another in such a way that the cage is arranged on the outside of the laminated core or the solid material component after the displacement and is preferably fastened.

A step of the method for assembling a rotor of an electrical machine preferably includes positioning a magnetic body in a receptacle of the cage.

When positioning, a magnetic body is advantageously moved in the radial direction, preferably from the outside inwards.

Alternatively, it is also possible that a magnetic body is inserted into a receptacle in the axial direction during positioning, preferably an axial end face of the hollow cylindrical base body of the cage being releasably attachable to the central part thereof in order to open and close axial access to a receptacle close.

Provision can also be made for the insertion bevels to guide the magnet body during positioning, so that it reaches its intended position.

Furthermore, an insertion bevel has the advantage that a magnetic body can only be used in the cage with a certain spatial orientation to the cage. Incorrect assembly of a magnetic body on a laminated core or on a solid material component can thus be avoided.

Advantageously, in both of the aforementioned alternatives, the further step of fastening follows, in which a magnetic body is fastened with a receptacle of the cage, in particular by means of adhesive. In the following, the inventive idea presented above is additionally expressed in other words.

This idea preferably relates to - in simplified form - a cage through which a magnet or a magnetic body can be positio ned during assembly on a rotor and is preferably firmly glued.

The cage is preferably a plastic cage.

Furthermore, it is favorable if the plastic cage in the case of wet-running rotors, such as in pumps, for example, contributes to a reduction in the splash losses, as a result of which the performance of the motor can also be increased.

The invention is explained in more detail below on the basis of exemplary embodiments in conjunction with associated drawings. Here show schematically:

Fig. 1 is a sectional view in the radial direction on a erfin

rotor according to the invention after a first (on the left side of the line ll-ll) and a second (on the right side of the line ll-ll) exemplary embodiment; and

2 shows a sectional view in the axial direction of the cage according to the invention from FIG. 1.

In the following description, the same reference numerals are used for the same objects.

For the sake of simplicity and brevity, FIGS. 1 and 2 are described below with one another.

Figure 1 shows a sectional view in the radial direction R on a rotor 10 according to the invention according to a first (left side of the line II-II) and a second (right side of the line II-II) embodiment, wherein Figure 2 is a sectional view in the axial direction on the inventive Cage 1 of Figure 1 shows.

1 and 2 show a rotor 10 of an electrical machine with a cage 1 for the relative positioning of magnetic bodies and a laminated core 12 to avoid eddy currents. Here, the cage 1 is attached to the outside of the laminated core 12.

The cage 1 and the laminated core 12 are designed with respect to one another in such a way that they have a transition or interference fit.

Furthermore, the cage 1 has a hollow cylindrical base body 2 and various receptacles 3 for the magnetic body 1 1 (magnetic body 1 1 only shown).

Each receptacle 3 penetrates the cylinder wall of the hollow cylindrical Grundkör pers 2 completely to form a passage from the outside to the inside.

Furthermore, the hollow cylindrical base body 2 has a central part along its height, which is arranged between two axial end faces S1, S2 arranged opposite one another.

One of the axial end faces S1, S2 of the exemplary embodiment shown on the right of the line II-II can be releasably attached to the central part in order to form an axial access to the receptacles 3.

In both exemplary embodiments, the axial end face S1, S2 are of circular design.

As shown in FIGS. 1 and 2, each receptacle 3 has insertion bevels 4 on the side, which guide a magnetic body 11 which can be inserted therein to its intended position relative to the hollow cylindrical base body 2 of the cage 1.

The insertion bevels 4 extend over the entire thickness of the cylinder wall of the hollow cylindrical base body 2 and are wedge-shaped, two insertion bevels 4 being arranged opposite each other.

Furthermore, the two insertion bevels 4 are designed such that they taper in a wedge shape in the radial direction R, in particular inwards in the radial direction R, so that the receptacles 3 for the exemplary embodiment taper inwards in the radial direction R on the right-hand side of the line II-II.

To the left of the line II-II, the insertion bevels 4 are designed such that they run in a wedge shape in the radial direction R, in particular outwards in the radial direction R, so that the receptacles 3 taper outwards in the radial direction R. Each receptacle 3 is polygonal, in particular rectangular, wherein each receptacle 3 also has four sides with at least two insertion bevels 4 which are arranged opposite one another.

As can be seen in the comparison of FIGS. 1 and 2, the sides of a receptacle 3 have different lengths, the shorter sides of a receptacle 3 being arranged on the axial end faces S1, S2 of the cage 1.

The relatively shorter sides of a receptacle 3 are thus formed by the axial end faces of the hollow cylindrical base body 2.

The cage 1 has a plastic material.

As can also be seen from FIGS. 1 and 2, a magnetic body is arranged in a form-fitting manner in a receptacle 3.

In other words, a receptacle 3 and a magnetic body 11 are matched to one another in such a way that the cage 1 clamps a magnetic body 11 in the receptacle 3 in order to center the magnetic body 11 in the receptacle 3 for gluing with an adhesive and temporarily until fixie to harden the adhesive.

As shown in particular in Figure 1, the cage 1 forms a continuous surface together with a magnetic body 11 as the outside.

Described in more detail, the cage 1 together with the magnetic bodies 11 forms a continuous, flush surface on the outside of the cage 1, as a result of which a pump effect and a cavity can be avoided during operation of the rotor 10.

In the middle of the laminated core 12, a shaft 13 is shown in Figure 1, which is connected to the laminated core 12.

A method for assembling the rotor 10 of an electrical machine is briefly explained below.

This includes the step of creating a rotor 10, which comprises joining the laminated core 12 to the shaft 13.

Furthermore, when the cage 1 and the laminated core 12 are created, they are aligned coaxially and axially displaced relative to one another in such a way that the cage 1 is fastened to the outside of the laminated core 12 after the displacement. Thereupon, magnetic bodies 11 are positioned in the receptacles 3 of the cage 1, where a magnetic body 11 is moved in the radial direction R during positioning, preferably from the outside inwards.

This applies e.g. B. for the embodiment on the left side of the line ll-ll of Figure 1.

A further exemplary embodiment is shown on the right-hand side of line II-II in FIG. 1, magnetic bodies 11 being inserted into each receptacle 3 in the axial direction A during positioning.

For this purpose, an axial end face of the hollow cylindrical base body 2 of the cage 1 can be detachably fastened to its central part in order to close or release axial access to the receptacles 3.

Thus, when positioning the lead-in chamfers 4 of a receptacle 3, the magnetic body 11, so that it reaches its intended position.

For final assembly, the two further alternatives are followed by the further step of fastening, in which the magnetic bodies 11 are glued to the receptacles 3 of the cage 1.

In the following, FIGS. 1 and 2 are described again in other words.

The laminated core 12 of the rotor 10 is joined to the shaft 13 in a manner not specified in any more detail.

Then the cage 1 is pushed over the rotor laminated core 12 and joined.

Through chamfers 4 on the cage 1, the surface magnets 11 and the magnetic bodies 11 can now be added to the rotor laminated core 12 from the radially outside (relates to the exemplary embodiment on the left-hand side of the line II-II of FIG. 1).

The cage 1 guides the surface magnets 11 or the magnetic bodies 11 during the assembly process, so that incorrect positioning can be avoided.

The magnets 11 and the magnetic body 11 are, for. B. connected with adhesive to the rotor laminated core 12.

The cage 1, which is designed as a plastic cage 1, can also have a slight pretension so that the magnets 11 can be mounted and fixed in the center of the gap 3 or in the receptacle 3 (when the plastic is curing or later in operation). If the fabric is relaxed, this has no influence on the positioning, since the glue or adhesive or the adhesive has taken over the fixation here).

The cage 1 fills the space between two adjacent surface magnets 11.

This can prevent fluid from getting into this space and causing splashing losses.

The presented embodiments are not limited to wet running applications. The cage 1 also serves as a positioning aid in a dry-running application.

Reference list

1 cage

2 hollow cylindrical body

3 recording

4 lead-in chamfers

10 rotor

11 magnetic body

12 sheet package

13 wave

51 axial end face

52 axial end face

A axial direction

R radial direction

Claims

1. Cage (1) for the relative positioning of magnetic bodies on a laminated core or on a solid material component of an electrical machine, comprising:

- A hollow cylindrical base body (2), and

- At least one receptacle (3) for a magnetic body (11).

2. cage according to claim 1,

- wherein the hollow cylindrical base body (2) comprises the at least one receptacle for a magnetic body (11),

the at least one receptacle (3) preferably at least partially penetrates the cylinder wall, in particular completely, in order to form a passage from the outside inwards,

- Preferably, the cage (1) has a plastic material.

3. cage according to claim 1 or 2,

- The hollow cylindrical base body (2) along its height comprises a central part, which is arranged between two axially end faces (S1, S2) arranged opposite one another,

- Preferably, an axial end face (S1, S2) on the central part can be detachably fastened to form axial access to the at least one receptacle (3),

- Preferably, an axial end face (S1, S2) is annular.

4. Cage according to one of the preceding claims,

- The at least one receptacle (3) laterally at least one insertion

Inclined (4) which leads a magnetic body (11) which can be inserted therein to its intended position relative to the hollow cylindrical base body (2), - The insertion slope (4) preferably extends over the entire thickness of the cylinder wall of the hollow cylindrical base body (2),

- The insertion slope (4) is preferably wedge-shaped,

- The at least one receptacle (3) preferably comprises two insertion bevels (4) which are arranged opposite one another.

5. Cage according to one of the preceding claims,

- Two insertion bevels (4) are designed such that they wedge-shaped in the radial direction (R), in particular inwards in the radial direction (R), so that the at least one inward in the radial direction (R) 3) tapered,

or

- Wherein two insertion bevels (4) are designed such that they wedge-shaped in the radial direction (R), in particular outwards in the radial direction (R), so that outwards in the radial direction (R) the at least one acceptance ( 3) tapered.

6. Rotor (10) of an electrical machine comprising:

a cage (1) according to one of the preceding claims,

- a laminated core to avoid eddy currents or a solid material component made of a solid material,

- The cage (1) is arranged on the outside of the laminated core (12) or the solid material component, in particular is fastened to the laminated core (12) or the solid material component,

- Wherein preferably the cage (1) and the laminated core (12) or the Vollmateri albauteil are designed such that they have a transition or press fit.

7. Rotor according to claim 6,

- A magnetic body (11) is arranged in the at least one receptacle (3), in particular in a form-fitting manner, - The at least one receptacle (3) and the magnetic body (11) are preferably geometrically matched to one another in such a way that the cage (1) clamps a magnetic body (11) in the at least one receptacle (3) in order to hold the magnetic body (11) in Center the holder (3) for gluing with an adhesive and fix it temporarily.

8. Rotor according to claim 6 or 7,

- The cage (1) together with a magnetic body (11) as the outside forms a continuous surface,

the cage (1), together with a magnetic body (11) on the outside of the cage (1), forms a continuous, flush surface, as a result of which a pump effect or a cavity can be avoided during operation of the rotor (10),

- Preferably, a shaft (13) with the laminated core (12) or the Vollma material component is connected.

9. Method for assembling a rotor of an electrical machine with the steps:

- creating a rotor according to one of claims 6 to 8,

- Preferably, the laminated core (12) or the solid material component is added to the shaft (13) when it is being created,

- Whereby when creating the cage (1) and the laminated core (12) or the solid material rialbauteil be coaxially aligned and axially displaced to each other such that after moving the cage (1) on the outside of the laminated core (12) or the solid material component and is preferably attached.

10. The method according to claim 9 with the further steps:

- positioning a magnetic body (11) in a receptacle (3) of the cage (1),

- A magnetic body (11) is moved in the radial direction (R) during positioning, preferably from the outside inwards,

or - When positioning a magnetic body (11) in the axial direction (A) is inserted into a receptacle (3), and preferably an axial end face of the hollow cylindrical base body (2) of the cage (1) is releasably attachable to the central part thereof, to open and close axial access to a receptacle (3),

- And in the case of both of the aforementioned alternatives, the further step of fastening preferably follows, in which a magnetic body (11) with a holder (3) of the cage (1) is fastened, in particular by means of adhesive.