DE102020119805A1 - Process for manufacturing a rotor, assembly system and electrical machine - Google Patents

Abstract

Method for manufacturing a rotor for an electrical machine, comprising the steps:- providing a rotor;- providing a guide tube with different diameters for expanding a holding element when pushed onto the rotor;- arranging a holding element on the guide tube and pushing the holding element in the direction of the rotor by laterally applying a force to the holding element with a tool, the tool being supported circumferentially on the holding element in such a way that it automatically adapts to the changing diameter of the holding element.

Description

The present invention relates to a method for producing a rotor for an electrical machine, an assembly system and an electrical machine.

Sufficiently high speed stability is an ever-increasing challenge for the rotors of electrical machines EP 2 149 965 A1 proposes in this context a rotor of a permanently excited synchronous machine, with the rotor being surrounded by a steel bandage on its lateral surface. This not only serves to fix the permanent magnets that are arranged on the surface of the rotor, but also to fix the entire package. The steel strip is wound with a certain pretensioning force. In practice, however, it has been shown that the prestressing forces that can be achieved during winding are not sufficiently high and are also difficult to adjust during winding. This also applies when the bandage or casing is not made of steel but of a carbon fiber reinforced material, such as in EP 0 212 552 B1 , which discloses a method for manufacturing a rotor for an electric motor with a wound bandage. the EP 0 631 364 A3 relates to a rotor for an electrical machine with a rotor core and a rotor jacket, which comprises a bandage made of fiber-reinforced plastic that radially supports the rotor core. The rotor core has an outer lateral surface with a small cone angle, on which the rotor casing is supported with an inner lateral surface having the same cone angle. However, this configuration is already very complex in terms of construction. In addition, the expected preload forces are also rather low here.

It is therefore an object of the present invention to specify a method for producing a rotor, an assembly system and an electrical machine which can withstand the highest speeds and can be produced cost-effectively and reliably.

This object is achieved by a method according to claim 1, by an assembly system according to claim 5 and by an electrical machine according to claim 10. Further advantages and features emerge from the subclaims and the description and the attached figures.

• - Bereitstellen eines Rotors;
• - Bereitstellen eines Führungsrohrs mit unterschiedlichen Durchmessern zum Aufweiten eines Halteelements, insbesondere einer Bandage, beim Aufschieben auf den Rotor;
• - Anordnen eines Halteelements auf dem Führungsrohr und Aufschieben des Halteelements in Richtung Rotor durch seitliches Aufbringen einer Kraft auf das Halteelement mit einem Werkzeug, wobei sich das Werkzeug derart umfänglich am Halteelement abstützt, dass es sich automatisch dem sich ändernden Durchmesser des Halteelements anpasst.

According to the invention, a method for manufacturing a rotor for an electrical machine comprises the steps:

• - Providing a rotor;
• - Providing a guide tube with different diameters for expanding a holding element, in particular a bandage, when pushed onto the rotor;
• - Arranging a holding element on the guide tube and sliding the holding element in the direction of the rotor by laterally applying a force to the holding element with a tool, the tool being supported on the holding element in such a way that it automatically adapts to the changing diameter of the holding element.

This enables a particularly process-reliable assembly of the holding element, in particular also of holding elements which have a small wall thickness. With the reduction in the wall thickness of the holding elements, the axial contact surface on the holding elements is reduced during joining. This inevitably leads to increased surface pressure on the holding elements and can result in damage to the material. This is made more difficult by the fact that there must be a clearance between the tool and the guide tube when the holding element is joined. In the past, this could lead to the retaining element being pinched between the tool and the mounting sleeve. By using a tool that rests against the holding element so that it automatically adapts to the changing diameter of the holding element during joining, it can be ensured that the tool rests securely even with very thin holding elements, with wall thicknesses of less than 1 mm, for example .

According to one embodiment, the rotor is a rotor of or for a permanently excited synchronous machine, comprising a multiplicity of permanent magnets arranged in or on the rotor. According to another embodiment, the rotor is a rotor for a current-excited synchronous machine. In principle, the rotor is not limited to the two aforementioned types of electrical machines. The method can be applied to all types of rotors for electrical machines.

According to a preferred embodiment, the holding element is in particular a ring-shaped or sleeve-shaped holding element. The holding element is preferably formed from a multi-component or composite material, in particular from a reinforced plastic, and in particular from a glass (GFK—glass fiber reinforced plastic) and/or carbon fiber reinforced plastic. In particular, the ring-shaped holding element is a CFRP bandage (CFRP—carbon fiber reinforced plastic). This is advantageously very light, stiff and also has good damping properties. Alternatively are also Mixed structures made of GRP and CFRP are possible, although this list is not to be understood as exhaustive. Further examples (in particular for fiber materials) are in particular Zylon or Aramid.

According to a preferred embodiment, the bandage has a wall thickness between 0.5 and 1.5 mm, particularly preferably between 0.6 and 1.0 mm, very particularly preferably in a range from 0.8 to 0.9 mm.

According to one embodiment, the holding element or the bandage can also be made of a metal material, such as steel, for example, or have or comprise a metal material.

• - Umfängliches Kontaktieren des Halteelements mit dem Werkzeug an einer Vielzahl von Stellen.

Dadurch wird ein gleichmäßiges Aufweiten des Werkzeugs ermöglicht bzw. erreicht.According to one embodiment, the method comprises the step:

• - Circumferential contact of the holding element with the tool at a large number of points.

This allows or achieves a uniform expansion of the tool.

• - Seitliches Kontaktieren des Halteelements bzw. axiales Aufbringen einer Kraft auf das Halteelement mit dem Werkzeug an einer Vielzahl von Stellen.

Hierdurch kann sichergestellt werden, dass es zu keinem Verkanten oder dergleichen beim Aufschieben kommt. Zudem kann die Flächenpressung gering gehalten werden.According to one embodiment, the method comprises the step:

• - Lateral contacting of the holding element or axial application of a force to the holding element with the tool at a large number of points.

In this way it can be ensured that there is no canting or the like when pushed on. In addition, the surface pressure can be kept low.

According to the invention, an assembly system for arranging a retaining element on a rotor of an electrical machine comprises a guide tube and an assembly sleeve, the guide tube having an outer diameter that changes in such a way that a retaining element can be expanded when it is arranged on the rotor, and the assembly sleeve has a radially movable assembly section for has contact with a holding element to be mounted, and wherein the mounting section has a multiplicity of end faces which are designed for frontal contact with the holding element, and wherein the mounting section has a multiplicity of contact surfaces which are designed for circumferential contact with the holding element, whereby the Mounting section can automatically adapt to changing diameters of the holding element. The advantages and features mentioned in connection with the method also apply analogously and correspondingly to the assembly system, or vice versa.

According to one embodiment, the mounting section is formed by a multiplicity of tabs, which extend along a longitudinal axis of the mounting sleeve. During assembly of the holding element, the longitudinal axis of the assembly sleeve extends along a rotor axis of the rotor. The contact surfaces and the end faces are advantageously formed on the ends of the tabs. Correspondingly, a tab advantageously has a contact surface and a front surface. According to one embodiment, the mounting sleeve is formed from a tubular section which is slotted in the area of the mounting section or has a large number of slots, as a result of which the aforementioned tabs can be formed.

Both metallic and non-metallic materials can be used as the material for the mounting sleeve.

According to one embodiment, the tabs are inclined towards the longitudinal axis in the initial state. In other words, in the initial state, the tabs are aligned at a slight angle with respect to the longitudinal axis of the assembly sleeve, in particular towards it.

According to one embodiment, a prestress, in particular a radially directed prestress, can be generated on the holding element via the mounting section, as a result of which a secure contact with the holding element can be ensured.

According to one embodiment, the tabs are designed and/or arranged to be resilient. In particular, the tabs or the mounting section are designed to be elastic or flexible, as a result of which the diameter can be adjusted.

According to one embodiment, the end faces and/or the contact faces are curved. As a result, reliable tracking and reliable contact of the mounting section can be achieved even with changing diameters of the holding element.

Such a mounting system can be operated by hand. Alternatively, the assembly system can also be part of a device, such as a machining center or a corresponding assembly plant. Alternatively, the assembly system can also be operated automatically using an industrial robot.

The invention further relates to an electrical machine, comprising a rotor which is produced using the method according to the invention. According to one embodiment, the electrical machine can be a permanently excited one act synchronous machine. Alternatively, it is a current-excited synchronous machine, with the possible types of electrical machines not being limited to the two aforementioned types of embodiment.

The electrical machine is preferably an electric motor, as is used in electrified motor vehicles, in particular in partially or fully electrified vehicles, that is to say in particular hybrid vehicles or electric vehicles. These can be motorcycles, commercial vehicles or, in particular, passenger cars. The electrical machine is preferably a traction motor for a motor vehicle.

Further advantages and features emerge from the following description of embodiments of the method with reference to the accompanying figures.

• 1: eine schematische Ansicht eines Rotors mit einer Vielzahl von umfänglich angeordneten Bandagen;
• 2: eine Ausführungsform eines Montagesystems;
• 3: eine Ausführungsform einer Montagehülse.

Show it:

• 1 1: a schematic view of a rotor with a multiplicity of circumferentially arranged bandages;
• 2 : an embodiment of a mounting system;
• 3 : an embodiment of a mounting sleeve.

1 shows a rotor 10 in a schematic view, comprising a rotor shaft 12 which extends along a rotor axis R. It can be seen that a multiplicity of bandages 20 are arranged on a laminated core 14 .

2 shows an embodiment of a mounting system, comprising a mounting sleeve 40 and a guide tube 30, which extend along a longitudinal axis L. The mounting sleeve 40 has a tube section 50 and a mounting section 42 adjoining it. The mounting section 42 has a contact surface 46 and an end face 44 . The end face 44 is intended to apply an axial force to a holding element or a bandage, which is not shown here. The bandage can be pushed along the longitudinal axis L via the guide tube 30 onto a rotor (not shown here) via the axial force. In order to ensure a secure contact of the end face 44, possibly also several, on the bandage, the contact surface 46 or several are provided. The contact surface bears circumferentially against the bandage, as a result of which the mounting section 42 expands when the bandage expands. A type of centering of the assembly sleeve 40 or of the assembly section 42 is advantageously effected via the contact surface 46, which enables working with extremely small joint clearances, cf. reference number 52. As a result, even thin and very thin bandages can be mounted without the risk of them jamming between the mounting section 42 and the guide tube 30 . In the embodiment shown here, the guide tube 30 has two conical sections 32 which are provided for increasing the diameter of the bandage. The pretension of the bandage can ultimately be built up by increasing the diameter.

3 shows an embodiment of a mounting sleeve 40, comprising a tube section 30 and a mounting section 42, which has a plurality of tabs 48. Slots 49 are formed analogously between the tabs 48 . Correspondingly, for example, such a mounting sleeve 40 can be produced by correspondingly slotting a suitably dimensioned tube. Each tab expediently has a contact surface or an end face at the end, cf 2 .

Such a mounting system can be operated by hand. Alternatively, the assembly system can also be part of a device, such as a machining center or a corresponding assembly plant. Alternatively, the assembly system can also be operated automatically using an industrial robot.

Reference List

10

rotor

12

rotor shaft

14

laminated core

20

retaining element, bandage

30

guide tube

32

conical section

40

mounting sleeve, tool

42

assembly section

44

face

46

contact surface

48

tab

49

slot

50

pipe section

52

joining game

R

rotor axis

L

longitudinal axis

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

• EP 2149965 A1 [0002]
• EP 0212552 B1 [0002]
• EP 0631364 A3 [0002]

Claims (10)

Method for manufacturing a rotor (10) for an electrical machine, comprising the steps: - Providing a rotor (10); - Providing a guide tube (30) with different diameters for expanding a holding element (20) when pushed onto the rotor (10); - Arranging a holding element (20) on the guide tube (30) and pushing the holding element (20) in the direction of the rotor (10) by laterally applying a force to the holding element (20) with a tool (40), the tool (40 ) is supported so circumferentially on the holding element (20) that it automatically adapts to the changing diameter of the holding element (20). procedure after claim 1 , wherein the holding element (20) is a CFRP bandage. procedure after claim 1 or 2 , comprising the step of: - peripherally contacting the holding element (20) with the tool at a plurality of points. Method according to one of the preceding claims, including the step: - Lateral contacting of the holding element (20) with the tool (40) at a large number of points. Mounting system for arranging a holding element (20) on a rotor of an electrical machine, comprising a guide tube (30) and a mounting sleeve (40), wherein the guide tube (30) has external diameters that change in such a way that a holding element (20) can be expanded when it is arranged on the rotor (10), and wherein the mounting sleeve (40) has a radially movable mounting section (42) for bearing against a holding element (20) to be mounted, and wherein the mounting section (42) has a multiplicity of end faces (44) which can be used for frontal bearing on the holding element (20 ) are trained, and wherein the mounting section (42) has a plurality of contact surfaces (46) which are designed for peripheral contact with the holding element (20), whereby the mounting section (42) can automatically adapt to changing diameters of the holding element (20). mounting system claim 5 , wherein the mounting portion (42) is formed by a plurality of tabs (48) which extend along a longitudinal axis (L) of the mounting sleeve (40). mounting system claim 6 , wherein the tabs (48) are inclined toward the longitudinal axis (L) in the initial state. Mounting system according to one of Claims 6 - 7 , wherein the tabs (48) are designed or arranged to be resilient. Mounting system according to one of Claims 5 - 8th , wherein the end faces (44) and / or the contact surfaces (46) are curved. Electrical machine, comprising a rotor, produced by a method according to one of Claims 1 - 4 .

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