DE102021114577A1 - Electrical machine and method for manufacturing an electrical machine - Google Patents

Abstract

Electrical machine (10), in particular for a vehicle, and a method for producing an electrical machine (10), having a housing (12), a stator (14) and a rotor (16), the stator (14) and/or or rotor (16) is at least partially enclosed by the housing (12), with a large number of slots (18) for receiving conductor sections (20) being formed in the stator (14), with a number of slots (18), preferably in A slot insulation element (22) is arranged in each slot (18), which extends through the slot (18) and surrounds the conductor piece(s) (20) arranged in the slot (18) to the outside, with the slot insulation element (22 ) has a first end (24) and a second end (26), wherein the slot insulation element (22) has a first end plate (28) at its first end (24) and a second end plate (30 ) is formed in each case fluid-tightly connected.

Description

The invention relates to an electrical machine, in particular for a vehicle, and a method for producing an electrical machine.

Electrical machines have a stator arranged in a stator space and a rotor arranged in a rotor space. There is an air gap between the stator and the rotor. The stator has slots in which electrically conductive conductor pieces are arranged. When the electrical machine is in operation, electrical current flows through the electrical conductor sections, generating heat in the process. There are different concepts to dissipate this heat. For example, DE 10 2017 101 094 A1 before flushing the conductor sections with a cooling liquid. To prevent this coolant from entering the rotor space, the rotor space must be sealed.

The object of the invention is to provide an electrical machine that is improved in comparison.

The object is achieved by an electrical machine according to claim 1.

The electrical machine, in particular for a vehicle, has a housing, a stator and a rotor. In this case, the stator and/or rotor are/is at least partially enclosed by the housing. A plurality of slots (stator slots) for receiving conductor pieces are formed in the stator. In several slots, preferably in all slots, a slot insulation element is arranged in each case, which extends through the slot and surrounds or encloses the conductor piece(s) arranged in the slot laterally outwards (i.e. towards the slot walls).

The slot insulation element has a first end and a second end. The slot insulation element is designed to be connected in a fluid-tight manner at its first end to a first end disk and at its second end to a second end disk. As a result, direct cooling of the conductor sections or of a winding formed from the conductor sections can be achieved. With the proposed configuration, a flow channel is formed cost-effectively and reliably around the conductor pieces arranged in a groove, so that the fluid cannot get into the rotor chamber (and thus into the air gap between the stator and rotor).

The slot isolation element is in particular connected in a fluid-tight manner to the first and/or second end disk such that no fluid can escape from the interior of the slot isolation element at the transition between the slot isolation element and the first and/or second end disk.

The stator can have a stator body which is designed in one piece or comprises a plurality of disc-shaped elements as a laminated stator core. The disk-shaped elements of the laminated stator core can be welded and/or stamped. The stator body extends along an axial direction and has an essentially sleeve-shaped or hollow-cylindrical structure.

The conductor pieces can, for example, be in the form of copper conductors and/or have a rectangular conductor cross section. The conductor pieces can be electrically connected to one another outside the stator body, in particular welded to one another.

The slot insulation element can preferably be designed and arranged within the slot of the stator in such a way that the slot insulation element projects out of the slot with its first end and its second end. This favors positioning and fastening of the end plates on the slot insulation element. The end of the slot insulation element that protrudes from the slot can protrude from the slot by at least the axial thickness of the first or second end disk.

The slot insulation element, the first end plate, the second end plate and the housing can preferably be designed and arranged in such a way that they at least partially delimit a flow channel through which a fluid for cooling the conductor sections can flow. A first flow channel section can be formed by the housing and the first end plate. A second flow channel section can be formed by the slot isolation element, in particular by all slot isolation elements. A third flow channel section can be formed by the housing and the second end plate.

The fluid can be introduced into the electric machine, into the first flow channel section. The fluid can then be conducted further through the second flow channel section and thus reach the third flow channel section. The fluid can be conducted out of the electric machine from the third flow channel section. In this way, the conductor pieces can be flushed and cooled by the fluid.

The fluid can be a liquid and/or gas which is/are suitable for cooling the conductor pieces (e.g. water, oil).

The first end disk and/or the second end disk can preferably each comprise an axial section and a radial section. The axial section and the radial section of the first end disk and/or the second end disk can each be designed as separate elements that are connected to one another in a fluid-tight manner. The axial section and the radial section of the first end disk and/or the second end disk can be connected to one another in a fluid-tight manner such that no fluid can flow at the transition from the radial section to the axial section, e.g. to the rotor space and/or into the air gap between the stator space and the rotor space can escape.

It is also conceivable that the axial section and the radial section of the first end disk are designed in one piece. Alternatively or additionally, the axial section and the radial section of the second end disk can be formed in one piece.

In the present case, “axial” means an alignment arranged parallel to the axial direction of the stator. Correspondingly, “radial” means an orientation perpendicular to the axial direction of the stator.

The first end disk and/or the second end disk can preferably be designed to be connected to the stator in a fluid-tight manner. In particular, the first end disk and/or the second end disk, together with its axial and/or radial section, can be designed to be connected to the stator in a fluid-tight manner. The fluid-tight attachment of the first end disk and/or the second end disk to the stator can be produced in that the first end disk and/or the second end disk are "injected" onto an end face of the stator, manufactured separately and glued (locally as a "ring" or over the entire surface ) or manufactured separately and attached to the face of the stator in conjunction with a conventional seal (O-ring, flat seal, etc.).

The slot insulation element, the first end plate and/or the second end plate can preferably be made/formed from a non-ferromagnetic material, in particular from plastic, in particular from polyetheretherketone (PEEK).

As an alternative to this, the slot insulation element, the first end disk and/or the second end disk can be made from a fiber-reinforced plastic, in particular from glass-fiber-reinforced plastic, carbon-fiber-reinforced plastic or a mixture thereof.

Preferably, a sleeve-shaped insulation element can optionally be arranged between the stator and the rotor. In particular, the sleeve-shaped insulation element can be arranged in the air gap between the stator and the rotor.

A seal can preferably be arranged between the housing and the first end disk and/or between the housing and the second end disk. This can be arranged in particular between the axial section of the first and/or the second end plate and the housing.

In particular, a vehicle, in particular a motor vehicle, with an electric machine according to the above statements can be proposed. With regard to the advantages that can be achieved in this way, reference is made to the relevant statements on the electrical machine. The measures described in connection with the electric machine can serve to further refine the vehicle.

• Zunächst erfolgt ein Einbringen von fluiddichten Nutisolationselementen, wobei jeweils ein Nutisolationselement in eine der im Stator ausgebildeten Nuten eingebracht wird. Die Nutisolationselemente können jeweils derart in die Nuten eingebracht werden, dass diese an ihrem ersten und/oder zweiten Ende zu den Stirnseiten des Stators jeweils bündig sind. Ebenso ist es denkbar, dass die Nutisolationselemente mit ihrem ersten und/oder zweiten Ende jeweils stirnseitig aus dem Stator herausragen, wobei das herausragende Ende der Nutisolationselemente jeweils insbesondere der Materialdicke einer anzubringenden ersten und/oder zweiten Stirnscheibe entsprechen kann.

The method for producing an electrical machine with a stator, a rotor and a housing can have the steps explained below:

• First, fluid-tight slot insulation elements are introduced, with one slot insulation element being introduced into one of the slots formed in the stator. The slot insulation elements can each be introduced into the slots in such a way that they are flush at their first and/or second end with the end faces of the stator. It is also conceivable for the first and/or second end of the slot insulation elements to protrude from the front of the stator, with the protruding end of the slot insulation elements being able to correspond in particular to the material thickness of a first and/or second end plate to be attached.

A first end disk and/or a second end disk is then attached, the first and/or the second end disk being connected in a fluid-tight manner to the slot insulation elements and in a fluid-tight manner to an end face of the stator.

Furthermore, one or more conductor pieces are introduced into the slots formed in the stator, with the one or more conductor pieces being in each case separated by a slot iso lation element are surrounded to the outside. In other words, the slot insulation element is arranged in each case between the slot or the slot walls and the respective conductor piece (or conductor pieces) arranged in the slot.

Furthermore, the conductor pieces are electrically contacted with one another. This can be implemented according to a desired circuit diagram, in particular by means of welding the ends of the conductor pieces together.

The method can in particular be a method for producing an electrical machine with one or more of the aspects described above.

The slot insulation elements can preferably be injected into the slots of the stator or manufactured separately and positioned (eg pushed in, inserted) into the slots of the stator.

The slot isolation elements and the first and/or second end disk can each be connected to one another in a fluid-tight manner by welding, by gluing or by spraying the first and/or the second end disk onto the slot isolation elements.

The first and/or the second end plate can be formed by molding the first and/or second end plate onto the end face of the stator, by gluing the first and/or second end plate to the end face of the stator or by sealing the first and/or second end plate relative to the Face of the stator, are fluid-tightly connected to each other.

• 1 einen Ausschnitt eines Längsschnitts einer elektrischen Maschine zwischen zwei Statornuten gemäß Schnitt B-B in 3;
• 2 einen Ausschnitt eines Längsschnitts der elektrischen Maschine gemäß 1 entlang einer Statornut gemäß Schnitt A-A in 3;
• 3 einen Ausschnitt eines Querschnitts der elektrischen Maschine gemäß 1 ;
• 4 einen Ausschnitt einer perspektivischen Ansicht auf den Stator der elektrischen Maschine gemäß 1 mit mehreren Nutisolationselementen;
• 5 einen Ausschnitt einer perspektivischen Ansicht auf die elektrische Maschine gemäß 1 mit einer ersten Stirnscheibe und
• 6 einen Ausschnitt einer perspektivischen Ansicht auf die elektrische Maschine gemäß 1 mit Leiterstücken.

Further advantageous configurations result from the following description and the drawing. The drawing shows, each schematically,

• 1 a section of a longitudinal section of an electrical machine between two stator slots according to section BB in 3 ;
• 2 according to a section of a longitudinal section of the electrical machine 1 along a stator slot according to section AA in 3 ;
• 3 according to a section of a cross section of the electrical machine 1 ;
• 4 according to a section of a perspective view of the stator of the electrical machine 1 with several slot insulation elements;
• 5 according to a section of a perspective view of the electrical machine 1 with a first end plate and
• 6 according to a section of a perspective view of the electrical machine 1 with ladder pieces.

1 shows a detail of a longitudinal section of an electrical machine 10 between two stator slots (according to section BB in 3 ). For the sake of clarity, only the longitudinal section of half the electrical machine 10 is shown. The electrical machine 10 extends along an axial direction 11, which in 1 is indicated by a broken line.

The electric machine 10 has a housing 12 , a stator 14 and a rotor 16 . In the present case, the stator 14 and the rotor 16 are enclosed by the housing 12 . The stator 14 comprises a stator lamination packet 17 in which a multiplicity of slots 18 for accommodating conductor pieces 20 is formed. In the example, four conductor sections 20 are arranged in each slot 18 (cf. 3 and 6 ).

In the present case, a slot insulation element 22 is arranged in each of the slots 18 and extends through the slot in each case.

2 shows a detail of a longitudinal section of the electrical machine 10 1 along a slot or stator slot 18 (according to section AA in 3 ). A longitudinal section through a wall of a slot insulation element 22 is shown. Analogous to 1 is in 2 also only half the electrical machine 10 is shown.

Each slot insulation element 22 surrounds the, for example, four conductor sections of a slot 18 laterally outwards. In other words, each slot insulation element 22 is arranged in the form of a sleeve inside the slot 18 and between the slot 18 and the conductor pieces 22 arranged inside the slot 18 . In the present case, the slots 18, the slot insulation elements 22 and the conductor pieces 22 each have a rectangular cross section (cf. 3 and 6 ).

Each slot insulation element 22 has a first end 24 and a second end 26 . Each slot insulation element 22 is connected in a fluid-tight manner at its first end 24 to a first end disk 28 and at its second end 26 to a second end disk 30 .

In the present case, the first end disk 28 and the second end disk 30 each have an axial section 34 and a radial section 36 . With their radial sections 36, the first end disk 28 and the second end disk 30 are each arranged in a fluid-tight manner on the end face 15 of the laminated core 17 of the stator. Between the two end plates 28, 30 and the respective end face A seal (O-ring, flat seal, etc.) can optionally be arranged in each case 15 of the stator laminated core 17 .

The first end disk 28 and the second end disk 30 rest with their axial sections 34 on the housing 12 (e.g. on a housing web), with a seal 40 being arranged between the housing 12 and the axial sections 34 of the two end disks 28, 30 , Which seals the connection between the axial sections 34 of the two end plates 28, 30 and the housing 12 in a fluid-tight manner.

This creates a fluid-tight flow channel 32 through which a fluid for cooling the conductor pieces 20 can flow. In the present case, the flow channel 32 has three sections.

The first flow channel section 21 is formed by the housing 12 and the first end plate 28 . The second flow channel section 23 is formed by the slot isolation elements 22 . The third flow channel section 25 is formed by the housing 12 and the second end plate 30 .

The fluid for cooling the conductor pieces 20 is introduced into the electrical machine 10 in the first flow channel section 21 . This is in the 1 and 2 indicated by an arrow. The fluid flows from the first flow channel section 21 through the second flow channel section 23 (ie through the slot insulation elements 22) into the third flow channel section 25. This is shown in FIGS 1 and 2 indicated by another arrow. The fluid is discharged from the electrical machine 10 again from the third flow channel section 25 . This is in the 1 and 2 indicated by a third arrow.

As the fluid flows along the flow channel 32 , it absorbs the heat from the conductor pieces 20 and transports it further along the flow channel 32 and out of the electric machine 10 . The fluid can then give off the heat, for example by means of a heat exchanger, and (cooled down) be fed back into the electric machine 10, into the first flow channel section 21. A cooling circuit can be implemented in this way.

In the example, an optional sleeve-shaped insulation element 38 is arranged between the stator 12 and the rotor 16 . The sleeve-shaped insulating element 38 is in the 1 and 2 only indicated by a dotted line. In the event of the fluid escaping from the flow channel 32 into the rotor chamber, the sleeve-shaped insulation element 38 serves as an optional additional seal for the rotor chamber.

3 shows a detail of a schematic cross section of the electrical machine 10 according to FIG 1 . The plan view of the end face 15 of the laminated stator core 17 is shown. The cross section 3 is therefore perpendicular to the longitudinal sections 1 and the 2 oriented. In 3 is the section AA, which corresponds to the longitudinal section of the 2 and the section BB, which corresponds to the longitudinal section of the 1 corresponds, shown.

In 3 three grooves 18 can be seen in each case, in each of which four conductor sections 20 are arranged in a row. A slot insulation element 22 is arranged in each case within the slots 18 . In the present case, the shape of the cross section of each slot insulation element 22 corresponds to the shape of the cross section (rectangular) of the respective slot 18.

The first end plate 28 is also shown. For the sake of clarity, this has only been shown partially, so that it partially provides a view of the end face 15 of the laminated core 17 of the stator.

the 4 until 6 illustrate the method steps for producing the electrical machine 10 using the example of the first end disk 28, these statements applying analogously to the second end disk 30. It is in each case a section of a perspective view of the end face 15 of the electrical machine 10 or its stator 14 according to FIG 1 shown.

As in 4 shown, the fluid-tight slot insulation elements 22 are introduced into the slots 18 in a first step. The slot insulation elements 22 can be injected into the slots 18 of the stator 14 or can be manufactured separately and positioned (eg pushed in, inserted) into the slots of the stator 14 . In the present case, the first ends 24 of the slot insulation elements each protrude from the face side of the laminated core 17 of the stator.

As in 5 shown, the first end plate 28 is attached in a next step. The first end plate 28 is connected in a fluid-tight manner to the slot insulation elements 22 and in a fluid-tight manner to the end face 15 of the laminated core 17 of the stator. For this purpose, the first end plate 28 can be injection molded, manufactured separately and glued on (locally as a "ring" or over the entire surface) or manufactured separately and attached to the end face 15 of the stator core 17 in conjunction with a conventional seal (O-ring, flat seal, etc.). .

In the present case, the sections of the first ends 24 of the slot insulation elements 22 that protrude from the stator core 17 correspond to the material thickness of the radial section 36 of the first end disk 28. In other words, the first ends 24 of the slot insulation elements 22 and the side of the radial section 36 of the first end disk 28 facing away from the stator core 17 are flush with one another.

As in 6 illustrated, the conductor pieces 20 are inserted into the grooves 18 in a further step. Subsequently, the conductor pieces 20 are contacted with one another according to a desired circuit diagram, in particular welded.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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 102017101094 A1 [0002]

Claims (11)

Electrical machine (10), in particular for a vehicle, having a housing (12), a stator (14) and a rotor (16), the stator (14) and/or rotor (16) being at least partially separated from the housing (12 ) are enclosed, with a plurality of slots (18) for receiving conductor pieces (20) being formed in the stator (14), characterized in that in a plurality of slots (18), preferably in all slots (18), one slot insulation element each (22) which extends through the groove (18) and surrounds the conductor piece(s) (20) arranged in the groove (18) to the outside, the groove insulation element (22) having a first end (24) and a has a second end (26), the slot insulation element (22) being connected in a fluid-tight manner to a first end plate (28) at its first end (24) and to a second end plate (30) at its second end (26). Electrical machine (10) after claim 1 , characterized in that the slot insulation element (22) is designed and arranged within the slot (18) in such a way that the slot insulation element (22) protrudes with its first end (24) and its second end (26) from the slot (18) protrudes. Electrical machine (10) after claim 1 or claim 2 characterized in that the slot insulation element (22), the first end plate (28), the second end plate (30) and the housing (12) are designed and arranged in such a way that they at least partially delimit a flow channel (32) through which a fluid can flow to cool the conductor pieces (20). Electrical machine (10) according to one of the preceding claims, characterized in that the first end plate (28) and / or the second end plate (30) each have an axial section (34) and a radial section (36), in particular the axial Section (34) and the radial section (36) of the first end plate (28) and/or the second end plate (30) are each formed as separate elements which are connected to one another in a fluid-tight manner. Electrical machine (10) according to the preceding claim, characterized in that the first end plate (28) and/or the second end plate (30), in particular together with its axial and/or radial section (34, 36), is fluid-tight with the stator (14) is formed connected. Electrical machine (10) according to one of the preceding claims, characterized in that the slot insulation element (22), the first end plate (28) and/or the second end plate (30) are made of a non-ferromagnetic material, in particular plastic, in particular polyetheretherketone ( PEEK) is formed. Electrical machine (10) according to one of Claims 1 until 5 , characterized in that the slot insulation element (22), the first end plate (28) and/or the second end plate (30) is made from a fiber-reinforced plastic, in particular from glass-fiber-reinforced plastic, carbon-fiber-reinforced plastic or a mixture thereof. Electrical machine (10) according to one of the preceding claims, characterized in that a sleeve-shaped insulating element (38) is arranged between the stator (14) and the rotor (16). Electrical machine (10) according to one of the preceding claims, characterized in that between the housing (12) and the first end plate (28) and/or between the housing (12) and the second end plate (30) there is a seal (40) is arranged. Method for producing an electrical machine (10) with a stator (14), a rotor (16) and a housing (12), in particular an electrical machine (10) according to one of the preceding claims, with the following steps: - Introducing fluid-tight slot insulation elements (22), in each case one slot insulation element (22) being introduced into one of the slots (18) formed in the stator (14); - Attaching a first end disk (28) and/or a second end disk (30), the first and/or the second end disk (28, 30) each being fluid-tight with the slot insulation elements (22) and fluid-tight with an end face (15) of the stator (14) is connected; - Insertion of one or more conductor sections (20) in the slots (18) formed in the stator (14), with the one or more conductor sections (20) in a slot (18) being surrounded on the outside by a slot insulating element (22). are and - Electrical contacting of the conductor pieces (20) with one another. Method according to the preceding claim, characterized in that the slot insulation elements (22) are injected into the slots (18) of the stator (14) or are manufactured separately and positioned in the slots of the stator (14), and/or that the slot insulation elements (22) and the first and/or second end plate (28, 30) in each case by welding, by gluing or by injection molding the first and/or the second end disk (28, 30) to the slot insulation elements (20) are connected to one another in a fluid-tight manner, and/or that the first and/or the second end disk (28, 30) are injection molded onto the first and/or second end disk (28, 30) to the end face (15) of the stator (14), by gluing the first and/or second end disc (28, 30) to the end face (15) of the stator (14) or by sealing the first and/or second end plate (28, 30) relative to the end face (15) of the stator (14), are connected to one another in a fluid-tight manner.

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