DE102020101849A1 - A rotor for an axial flux machine, a method for producing a rotor for an axial flux machine and an axial flux machine - Google Patents

Abstract

The invention relates to a rotor (1) for an axial flux machine (2) that can be operated electrically, as a motor and / or as a generator, comprising a carrier (3) which is used to hold a plurality of magnetic elements (4) and to hold flux guide elements which conduct the magnetic flux (5) is formed. According to the invention, the carrier (3) comprises a ring pot-like carrier part (6) with a ring pot receptacle (A), which is at least partially open in the axial direction and extends circumferentially, for receiving the plurality of magnetic elements (4) and for receiving the flux guiding elements ( 5).

Description

The present invention relates to a rotor for an electrical, motor-driven and / or generator-driven axial flux machine, comprising a carrier which is designed to accommodate a plurality of magnetic elements and to accommodate a plurality of flux guide elements which conduct the magnetic flux. The invention also includes a method for producing such a rotor and an axial flow machine having such a rotor.

From the DE 10 2013 218 829 A1 a rotor for an axial flux machine is already known. In this rotor, the rotor laminations form a type of frame into which inlays are integrated. The rotor laminations have individual punchings for both the magnets and the inlays.

Further structures of rotors for axial flux machines or of axial flux machines themselves are described, inter alia, by the DE 10 2017 204 434 A1 , the DE 10 2005 053 119 A1 or the DE 10 2004 038 884 A1 .

The magnetic flux in an axial flux motor (electric motor) is axially directed in the air gap between the stator and rotor. A laminated rotor for high speeds and frequencies is layered in the axial direction. The axial magnetic flux has to overcome the adhesive layers, as a result of which the magnetic circuit experiences a shear (additional air gap) and loses its efficiency. This in turn causes the engine to lose power. For the axial magnetic flux, SMC (soft magnetic components / soft magnetic powder) is often used, since a 3D flux without significant eddy currents is possible here. A homogeneous SMC rotor is possible for smaller rotors as long as the mechanical load does not exceed the low strength of the SMC.

The present invention is based on the object of providing a rotor, in particular a rotor with mechanically unstable flux guide elements as rotor material, for an axial flux machine, which is further improved with regard to its mechanical strength properties. Furthermore, the invention is based on the object of providing a method for producing such a rotor and an axial flux machine with such a rotor.

This object is achieved by a rotor with the features of claim 1, a method for producing a rotor with the features of claim 12 and an axial flow machine with the features of claim 13. Advantageous developments of the invention are defined by the dependent claims. A rotor according to the invention for an electrical, motor-driven and / or generator-driven axial flux machine comprises a carrier which is designed to accommodate a plurality of magnetic elements and to accommodate a plurality of flux guiding elements which conduct the magnetic flux. The carrier comprises a ring pot-like carrier part with a ring pot receptacle, which is at least partially open in the axial direction and extends circumferentially, for receiving the plurality of magnetic elements and for receiving the plurality of flux guiding elements which conduct the magnetic flux. This creates a rotor for an axial flow machine which is further improved in terms of its mechanical strength. This is particularly important in the case of axial flux machines with a higher output. The rotor according to the invention is advantageously designed for axial flux machines with an output of 1 kilowatt to approximately 1000 kilowatts. An axial flux machine with the structure according to the invention is designed to provide up to approximately 500 Nm of torque.

An axial flux machine in the sense of the invention is characterized in that the magnetic flux generated in the air gap between the rotor and stator extends in the axial direction parallel to the axis of rotation of the machine.

According to an advantageous embodiment of the invention, it can be provided that the carrier part is designed in one piece, which in turn improves the mechanical strength of the rotor.

According to a further preferred further development of the invention, it can also be provided that the carrier part is designed to be completely open in the axial direction, as a result of which the magnetic flux conducting properties are further improved.

According to a particularly preferred embodiment of the invention, it is provided that the carrier comprises at least two carrier parts which are arranged with their bases next to one another and connected to one another on the base side, in particular welded or riveted to one another. The two carrier parts are advantageously designed to be identical. In such a rotor design, the axial flux motor has a stator on each of the two axial end faces of the rotor, which stator generates, for example, a rotating magnetic field while forming a respective axial air gap. The advantageous effect of this embodiment is based in particular on the fact that the magnetic forces within the rotor cancel each other out or are eliminated in the carrier due to the one-piece carrier with two firmly connected carrier parts.

It can also be provided that the bottoms of the two carrier parts have corresponding positive locking means, via which mutual rotation of the two carrier parts can be prevented, for example when the two carrier parts are riveted, then this riveted connection can be relieved.

Furthermore, the invention can also be further developed in such a way that the carrier part has an essentially S-shaped profile when viewed in an axial longitudinal section. In particular, the two axially open ring pot-like areas of the carrier part are of different sizes or have different radial widths, with the large number of magnetic elements and the flux-conducting elements conducting the magnetic flux being arranged in the larger of the two ring-pot-like areas. In this way, a receiving space for the magnetic elements and the flux guide elements can be created in a structurally simple manner, and the smaller S-bend section can be used to create a spring-elastic receiving in the radial direction for arrangement on a rotor shaft.

It can also be advantageous to further develop the invention in such a way that the magnetic elements and the flux guiding elements which conduct the magnetic flux are arranged circumferentially alternately and radially in a star shape in the carrier part, whereby an advantageous guidance of the magnetic field lines can be achieved. Alternatively, the magnet elements and the flux guide elements can also be arranged circumferentially inclined at an angle. The two carrier parts of the carrier are preferably equipped identically, so that when arranged as a one-piece carrier in which the two carrier parts are connected to one another at the bottom, the magnets and the flux guide elements of the two carrier parts point in different directions at an angle.

According to a further preferred embodiment of the subject matter of the invention, it can be provided that the magnetic elements and the flux guiding elements which conduct the magnetic flux are firmly connected to one another, in particular in such a way that the formation of an air gap between the magnetic element and the flux guiding element is reliably prevented. This fixed connection can be made for example by gluing. Finally, the invention can also be implemented in an advantageous manner in such a way that the flux guiding elements which conduct the magnetic flux are firmly attached to the inner surface of the outer radial support wall, advantageously no fixed connection or connection with or on the inner surface of the inner radial support wall and there is no fixed connection or connection with or on the inner support wall on the side of the pot bottom. The advantage that results from this is in particular that, on the one hand, there is a firm connection of the magnetic elements and the flux guide elements in the support part, and on the other hand, any tension forces that may occur in the event of a slight bending of the support parts - for example due to high centrifugal forces at high speeds of the Axial flux machine - do not occur because the magnetic elements are not glued to other places within the carrier part.

Finally, the invention can also be implemented in an advantageous manner to the effect that the magnet elements are designed to be divided, in particular that the magnet elements are divided in a plane parallel to their contact surface with the flux guiding elements which conduct the magnetic flux and / or in a plane perpendicular to the contact surface with the the magnetic flux conducting flux guide elements are divided. Such a construction or such a divided construction of the magnet elements can compensate for expansions of the carrier parts in an improved manner and avoid damage.

According to a further advantageous embodiment of the invention, it can be provided that the carrier part has elements for positioning the magnetic elements and / or the flux guiding elements which conduct the magnetic flux, these elements being formed in one piece with the carrier part. The advantage of this configuration is that a further improved strength of the connection between the carrier part and the magnet and flux guide elements arranged therein can be achieved.

According to a further preferred development of the invention, it can also be provided that the carrier is designed to be magnetically non-conductive, as a result of which the magnetic flux properties of the rotor can be further improved. The carrier is preferably formed from magnetically non-conductive steel, in particular from stainless steel.

• - Formen und Bereitstellen eines topfringförmigen Trägers aus einem nichtmagnetischen Material,
• - Bereitstellen der Magnetelemente und der den Magnetfluss leitenden Flussleitelemente,
• - Herstellen einer festen Verbindung zwischen den Magnetelementen und den Flussleitelementen,
• - Einbringen der Magnetleitelemente und der Flussleitelemente in den ringtopfförmigen Träger und Befestigen der Flussleitelemente und der Magnetelemente an der inneren Mantelfläche der äußeren radialen Trägerwand.

Furthermore, the object is achieved by a method for manufacturing a rotor for an axial flux motor, comprising the following method steps:

• - Forming and providing a cup ring-shaped carrier made of a non-magnetic material,
• - Provision of the magnetic elements and the flux guiding elements that conduct the magnetic flux,
• - Establishing a firm connection between the magnetic elements and the flux guide elements,
• - Introducing the magnet guide elements and the flux guide elements into the ring-pot-shaped carrier and fastening the flux guide elements and the magnet elements to the inner surface of the outer radial carrier wall.

A corresponding steel or a corresponding steel alloy is preferably used as the non-magnetic material.

Furthermore, the object of the invention is achieved by an axial flux machine that can be operated as a motor and / or generator and has a rotor, designed as described above.

• - einen Rotor mit einem ersten Träger mit einem ringtopfartig ausgebildeten Trägerteil und mit einer Vielzahl von Magnetelementen und einer Vielzahl von den Magnetfluss leitenden Flussleitelementen, die in einer ringtopfartigen Ausnehmung des Trägerteils angeordnet sind, und mit einem zweiten im Wesentlichen identisch zum ersten Träger ausgebildeten Träger, wobei der erste Träger und der zweite Träger mit ihren Böden aneinander angeordnet und bodenseitig miteinander fest verbunden sind, sowie
• - einen ersten Stator mit einer Mehrzahl von Spulenmagneten, der an einer ersten axialen Rotorseite unter Bildung eines ersten Luftspalts angeordnet ist, und der ein Magnetfeld erzeugt, welches sich im Wesentlichen in axialer Richtung in Richtung Rotor erstreckt, und
• - einen zweiten Stator mit einer Mehrzahl von Spulenmagneten, der an einer zweiten axialen Rotorseite unter Bildung eines zweiten Luftspalts angeordnet ist, und der ein Magnetfeld erzeugt, welches sich im Wesentlichen in axialer Richtung in Richtung Rotor erstreckt. Die Trägerteile können alternativ auch gegeneinander verdreht sein, wobei die Statoren dann entsprechend verdreht zueinander angeordnet sind. Bevorzugt sind die Trägerteile derart ausgestaltet und miteinander fest verbunden, dass eine spiegelsymmetrische Anordnung gegenüber einer zwischen den beiden Böden angeordneten Spiegelebene gegeben ist.

The axial flow machine preferably comprises

• a rotor with a first carrier with a carrier part designed like a ring pot and with a plurality of magnet elements and a plurality of flux guiding elements which conduct the magnetic flux, which are arranged in a ring pot-like recess of the carrier part, and with a second carrier that is essentially identical to the first carrier, wherein the first carrier and the second carrier are arranged with their bases next to one another and are firmly connected to one another on the base side, as well as
• a first stator with a plurality of coil magnets, which is arranged on a first axial rotor side with the formation of a first air gap, and which generates a magnetic field which extends essentially in the axial direction in the direction of the rotor, and
• a second stator with a plurality of coil magnets, which is arranged on a second axial rotor side with the formation of a second air gap, and which generates a magnetic field which extends essentially in the axial direction in the direction of the rotor. The carrier parts can alternatively also be rotated with respect to one another, the stators then being arranged correspondingly rotated with respect to one another. The carrier parts are preferably designed and firmly connected to one another in such a way that there is a mirror-symmetrical arrangement with respect to a mirror plane arranged between the two floors.

Overall, a high level of effectiveness is achieved by reducing the eddy currents at high frequencies. For this purpose, SMC is used in the form of flux guide elements. These allow effective three-dimensional flow guidance. In combination with stainless steel sheets to mechanically hold the SMC flux guide elements, the parasitic magnetic short circuit is minimized. The bent sheet metal parts made of stainless steel absorb the centrifugal forces and torques in the rotors of high-performance motors. The arrangement of the spokes in the magnetic elements allows the motor to have an increased power density while at the same time using less magnetic material. The rotor designed for this purpose contains two cup-shaped support parts, in particular made of stainless steel, into which the flux guide elements, which are designed as SMC components, and the magnetic elements in a spoke arrangement are inserted and glued. The carrier parts formed as stainless steel rings have high rigidity and strength because they preferably consist of one piece. The cup shape of the rings allows the magnetic elements and the flux guide elements to be held securely. The continuous radial ring surface is suitable for transmitting a high torque. The two-sided support parts distribute the force input symmetrically. Formed and cut sheet metal parts and uniform SMC sintered parts can be used for cost-effective production.

The invention is explained in more detail below with reference to figures without restricting the general inventive concept.

• 1 einen erfindungsgemäßen Rotor in einem Teil-Axialschnitt in perspektivischer Darstellung,
• 2 ein Trägerteil des erfindungsgemäßen Rotors in einem Teil-Axialschnitt in perspektivischer Darstellung,
• 3 eine erfindungsgemäße Axialflussmaschine in perspektivischer Darstellung, wobei in der oberen Zeichnungsfigur ein erster Stator und in der unteren Darstellung ein zweiter Stator nebst dem zwischen dem ersten und zweiten Stator anzuordnenden schematisch dargestellten Rotor prinzipiell veranschaulicht ist, und
• 4 die Axialflussmaschine gemäß 3 in Perspektivdarstellung.

Show it:

• 1 a rotor according to the invention in a partial axial section in a perspective view,
• 2 a support part of the rotor according to the invention in a partial axial section in a perspective view,
• 3 an axial flux machine according to the invention in a perspective representation, wherein a first stator is illustrated in the upper drawing figure and a second stator in addition to the schematically illustrated rotor to be arranged between the first and second stator is illustrated in principle in the lower drawing, and
• 4th the axial flux machine according to 3 in perspective view.

1 shows a rotor 1 for an axial flux machine that can be operated electrically, as a motor and / or as a generator 2 , comprising a carrier 3 , which is used to hold a large number of magnetic elements 4th and for receiving a plurality of flux guide elements which conduct the magnetic flux 5 is trained. The carrier 3 has a carrier part designed like a ring pot 6th with a ring pot receptacle which is at least partially open in the axial direction and extends circumferentially A. to accommodate the large number of magnetic elements 4th and for receiving the plurality of flux guiding elements which conduct the magnetic flux 5 on. In the illustrated embodiment, the carrier is 3 formed by two identically designed carrier parts 6th and 60 , with the two support parts 6th , 60 Arranged back to back and with their pot base parts of the ring pot holder A. lie against one another and are connected to one another in one piece via a welded connection or via rivets or the like are. In 2 is the carrier part 6th , 60 shown as such, with holes being provided in the bottom of the pot in the embodiment shown, for example around two support parts via rivets 6th , 60 to connect with each other. The carrier part 6th , 60 is S-shaped seen in an axial longitudinal section. The two axially open ring pot-like areas of the carrier part created by the S-bend shape 6th , 60 are of different sizes. They have different radial widths, with the large number of magnetic elements in the larger of the two ring pot-like areas 4th as well as the large number of flux guiding elements which conduct the magnetic flux 5 are arranged. The smaller S-bend area (in the picture below) serves as a spring-elastic area over which the rotor 1 can be arranged by means of a press fit on a rotor shaft.

The magnetic elements 4th and the flux guiding elements which conduct the magnetic flux 5 are circumferentially alternating and radially star-shaped in the carrier part 6th arranged. The magnetic elements 4th and the flux guiding elements which conduct the magnetic flux 5 are firmly connected to each other. The axially arranged stator (s. 3 ) generated magnetic field is in principle by the magnetic flux shown in the form of arrows B. shown. The magnetic field lines run within the two air gaps 10 , 13th between the rotor 1 and the two stators arranged axially on the end face 8th , 11 essentially axially perpendicular in the flux guide elements 5 , further through an adjacent magnetic element 4th into the adjacent flux guide element 5 and straight back out towards the stator 8th , 11 .

The flux guide elements that conduct the magnetic flux 5 are common with the magnetic elements 4th inside the ring pot holder A. , arranged circumferentially alternating and essentially star-shaped and firmly glued to the inner surface of the outer radial support wall (in the picture above). All other contact surfaces between the carrier part 6th , 60 and flux guide elements 5 and magnetic elements 4th remain disconnected. The flux guide elements 5 are alternately magnetized circumferentially, so that on a north pole N a south pole S. follows and vice versa. Between two adjacent flux guide elements 5 is in each case a magnetic element designed as a square disk 4th arranged, each magnetic element 4th is magnetized in such a way that the circumferentially opposing surfaces of the magnetic element 4th form different magnetic poles. Here are the magnetic elements 4th aligned or arranged in such a way that they have the same magnetic polarity as the adjacent flux guide element 5 facing this. A flux guide element magnetized with N. 5 thus has a magnetic element on each of the two sides aligned in the circumferential direction 4th arranged adjacent, each of which rests with its N-magnetized side. Accordingly, one has with S. magnetized flux guide element 5 one magnetic element each on both sides aligned in the circumferential direction 4th arranged adjacent, which with his S. magnetized side.

In the 3 and 4th is an axial flow machine 2 shown in their basic structure. The axial flow machine 2 includes a rotor 1 , the one here schematically without its support parts 6th , 60 , but with circumferentially alternating magnetic elements 4th and flux guide elements 5 is shown. In the illustration above is a first stator 8th shown in a plan view from the inside, so that here the individual stator coils are good 9 of the stator 8th are recognizable. Two adjacent stator coils are advantageous in each case 9 interconnected, with a total of six adjacent stator coils 9 result in three stator coil packs, each controlled at an angle of 120 degrees. Would be the first stator 8th , the upper illustration folded down by 180 degrees and forming a first air gap 10 from the rotor 1 kept axially spaced, the in 4th Axial flux motor shown schematically 2 result. In the illustration below, from 3 A top view of the remaining stator-rotor core is shown, with the second stator 11 , axially through a second air gap 13th spaced, the rotor 1 wearing.

The invention is not limited to the embodiments shown in the figures. The above description is therefore not to be regarded as restrictive, but rather as explanatory. The following patent claims are to be understood in such a way that a named feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. If the patent claims and the above description define “first” and “second” features, this designation serves to distinguish between two similar features without defining an order of precedence.

List of reference symbols

1

rotor

2

Axial flow machine

3

carrier

4th

Magnetic elements of a first group

40

Magnetic elements of a second group

5

Flux guide elements of a first group

50

Flux guide elements of a second group

6th

first carrier part

60

second support part

8th

first stator

9

first group of coil magnets

10

first air gap

11

second stator

12th

second group of coil magnets

13th

second air gap

A.

Ring pot holder

B.

Magnetic flux

N

Magnetic north pole

S.

Magnetic south pole

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 102013218829 A1 [0002]
• DE 102017204434 A1 [0003]
• DE 102005053119 A1 [0003]
• DE 102004038884 A1 [0003]

Claims (14)

A rotor (1) for an axial flux machine (2) that can be operated electrically, as a motor and / or as a generator, comprising a carrier (3) which is used to hold a plurality of magnetic elements (4) and a plurality of flux guide elements (5 ), characterized in that the carrier (3) has a first ring pot-like carrier part (6) with a ring pot receptacle (A), which is at least partially open in the axial direction and extends circumferentially, for receiving a plurality of magnetic elements (4) of a first group and for receiving the flux guiding elements (5) of a first group which conduct the magnetic flux. Rotor (1) Claim 1 , characterized in that the carrier part (6) is designed in one piece. Rotor (1) according to one of the preceding claims, characterized in that the carrier part (6) is designed to be completely open in the axial direction. Rotor (1) according to one of the preceding claims, characterized in that the carrier (3) comprises a second carrier part (60), the first carrier part (6) and the second carrier part (60) being arranged with their bottoms against one another and connected to one another at the bottom , in particular welded or riveted together. Rotor (1) according to one of the preceding claims, characterized in that the carrier part (6) has a substantially S-shaped profile when viewed in an axial longitudinal section. Rotor (1) according to one of the preceding claims, characterized in that the magnetic elements (4) and the flux guiding elements (5) conducting the magnetic flux alternate circumferentially and are advantageously arranged radially in a star shape in the carrier part (6). Rotor (1) according to one of the preceding claims, characterized in that the magnetic elements (4) and the flux guiding elements (5) which conduct the magnetic flux are firmly connected to one another. Rotor (1) according to one of the preceding claims, characterized in that the flux guiding elements (5) conducting the magnetic flux are firmly connected to the inner surface of the outer radial support wall, advantageously no fixed connection to the inner surface of the inner radial support wall and none There is a fixed connection with the inner support wall on the side of the pot bottom. Rotor (1) according to one of the preceding claims, characterized in that the magnet elements (4) are designed to be divided, in particular that the magnet elements (4) are divided in a plane parallel to their contact surface with the flux guide elements (5) which conduct the magnetic flux and / or are divided in a plane perpendicular to the contact surface with the flux guiding elements (5) which conduct the magnetic flux. Rotor (1) according to one of the preceding claims, characterized in that the carrier part (6; 60) has elements for positioning the magnetic elements (4; 40) and / or the flux guiding elements (5) conducting the magnetic flux, these elements being integral with the Support part (6; 60) are formed. Rotor (1) according to one of the preceding claims, characterized in that the carrier (3) is designed to be magnetically non-conductive. Method for producing a rotor (1) according to one of the preceding claims, comprising the following method steps: - Shaping and providing a cup ring-shaped carrier (3) made of a magnetically non-conductive material, - Provision of the magnetic elements (4) and the flux guiding elements (5) which conduct the magnetic flux, - connecting the magnetic elements (4) to the flux guide elements (5), - Introducing the magnet elements (4) and the flux guide elements (5) into the ring-pot-shaped carrier (3) and attaching the flux guide elements (4) and the magnet elements (4) to the inner surface of the outer radial carrier wall. Axial flux machine (2) which can be operated as a motor and / or generator, characterized by a rotor according to one of the preceding Claims 1 - 11 . Axial flux machine (2) according to Claim 13 , comprising - a rotor (1) with a first carrier (3) with a ring pot-like carrier part (6) and with a plurality of magnetic elements (4) and a plurality of the magnetic flux conducting flux guide elements (5), which are in a ring pot-like recess of the Carrier part (6) are arranged, and with a second carrier (3) which is essentially identical to the first carrier (3), the first carrier (3) and the second carrier (3) being arranged with their bases next to one another and firmly connected to one another at the base are, preferably such that a mirror-symmetrical arrangement is given with respect to a mirror plane arranged between the two floors, and - a first stator (8) with a plurality of coil magnets (9), which is arranged on a first axial rotor side with the formation of a first air gap (10), and which generates a magnetic field which extends essentially in the axial direction towards the rotor (1 ), and - a second stator (11) with a plurality of coil magnets (12), which is arranged on a second axial rotor side with the formation of a second air gap (13), and which generates a magnetic field which is essentially in the axial direction extends in the direction of the rotor (1).

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