DE102021206596A1 - Rotor for an electric machine - Google Patents

Abstract

The invention relates to a rotor for an electrical machine having a shaft (1) with a first shaft element (2), the first shaft element (2) having a first bearing seat (4) of the shaft (1) and a joining stop (7), wherein laminated cores (9) are joined against the joining stop (7) on the first shaft element (2).

Description

The invention relates to a rotor for an electrical machine having a shaft with a first shaft element, the first shaft element having a first bearing seat of the shaft and a joining stop, laminated cores being joined against the joining stop on the first shaft element.

Furthermore, the invention relates to an electrical machine with the inventive rotor and a method for producing a rotor.

Known rotors for electrical machines have laminated stacks of laminations that are joined, fixed and, if necessary, braced on a shaft. This requires complex joining processes with a large number of additional elements, such as spacer rings, union nuts and retaining rings, in order to fix the laminated core and to brace it axially. In a known reduction of the additional elements, for example by replacing union nuts with caulking of balancing disks, this leads to an uncertain design of the axial tension, since the axial pretensioning force has a greater variance when caulking.

A manufacturing process and an electrical machine of the type mentioned by the DE 10 2018 204 436 A1 famous. Disk packs are arranged for assembly on a hollow shaft and clamped axially between two radial projections. The hollow shaft has a radial projection and the other radial projection has a plug-in shaft arranged coaxially in the hollow shaft. By pressing the stub shaft into the hollow shaft, the hollow shaft is expanded radially, so that the disk packs enter into a press connection with the hollow shaft in the radial direction.

From the JP 2005 - 184 957 A a weight-reduced rotor of an electrical machine with improved heat dissipation is known, the improved heat dissipation and the face reduction being made possible by cutouts in the iron core.

the DE 10 2016 211 246 A1 discloses an electric machine with a two-part shaft, with the rotor being arranged between and connected to the shaft ends. The rotor has a magnetic element receptacle that accommodates a magnetic element.

From the DE 10 2019 113 596 A1 an electric machine for driving a motor vehicle is known, which provides for fastening of rotor laminations on a rotor shaft in such a way that tolerance compensation is made possible. Tolerance compensation is effected by an end plate.

Against this background, the invention is based on the object of designing a rotor of the type mentioned at the outset in such a way that a rotor can be produced with a smaller number of components and in a simpler, safer process.

This object is achieved with a stator according to the features of patent claim 1 and an electrical machine and a production method according to the independent claims. The dependent claims relate to particularly useful developments of the invention.

According to the invention, a rotor for an electrical machine is therefore provided which has a shaft with a first shaft element, the first shaft element having a first bearing seat of the shaft and a joining stop. On the first shaft element, laminated cores are joined against the joining stop and preferably preassembled, for example in the form of a transverse interference fit, a longitudinal interference fit or by means of a positive fit. A second shaft element is connected to the first shaft element by means of a mechanical connection, the second shaft element bracing the laminated cores against the joining stop and having a second bearing seat of the shaft.

The two shaft elements thus form the shaft, or they assume the function of the shaft and additional elements by supporting, fixing and bracing the laminated cores and also forming the bearing seats of the shaft. This means that additional elements such as union nuts or spacer rings can be omitted, which simplifies production and saves costs.

The joining stop is preferably designed as a shaft shoulder, a locking ring or a spacer ring.

A preferred embodiment provides that the mechanical connection, which connects the two shaft elements to one another, is designed as a securing element, preferably as a pin or a bayonet lock. This enables a particularly cost-effective and reliable mechanical connection.

It has proven to be advantageous for the first shaft element and/or the second shaft element to have external teeth, since this means that additional components, in this case a gear wheel, are not required can be tet, whereby the manufacturing process is further simplified and reduced.

The first shaft element and/or the second shaft element preferably has a radial snug fit for a balancing disk and/or for rotor assemblies. A radial fit in the sense of a transition fit or press fit of the shaft elements with a balancing disk and/or a rotor stack enables a defined position of the balancing disk and/or the rotor stack and a slight imbalance in the stator.

A preferred embodiment of the rotor has a first shaft element and/or a second shaft element which has an oil bore so that oil for cooling the end winding can be guided axially along the shaft elements and can exit radially from the shaft elements.

A particularly practical embodiment has a first shaft element and/or a second shaft element, which has balancing surfaces for removing and/or applying material. As a result, the function of a balancing disk can be integrated into the shaft elements and the number of components can be further reduced by dispensing with a balancing disk.

A preferred embodiment of the rotor has a spring element for axially bracing the laminated cores, which is preferably a cup spring. This enables process-reliable clamping of laminated cores with particularly low compressibility, even with high manufacturing tolerances.

It has turned out to be advantageous that the first shaft element and the second shaft element have fits for concentric alignment of the first shaft element to the second shaft element, since this enables small tolerances of the rotor, in particular a small imbalance.

Furthermore, an electrical machine has a rotor according to the invention.

The method according to the invention for producing a rotor preferably serves to produce a rotor according to the invention. Laminated cores are joined onto a first shaft element, the laminated cores being axially braced. A second shaft element is mechanically connected to the first shaft element in order to brace the laminated core against a joining stop of the first shaft element.

• 1 einen Rotor einer elektrischen Maschine im Schnitt.

The invention permits numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and is described below. This shows in

• 1 a rotor of an electrical machine in section.

1 shows a rotor of an electrical machine, for example a traction machine for motor vehicles, with a shaft 1 with a first shaft element 2 and a second shaft element 3. The first shaft element 2 has a first bearing seat 4 for mounting the stator in the electrical machine and external teeth 5 mechanical power transmission. An oil bore 6 is provided for conducting oil axially through the first shaft member 2 and for radial exit onto the end winding. The first shaft element 2 also has a joining stop 7, which is designed as a shaft shoulder, for forming a snug fit for a balancing disk 8. The laminated laminated cores 9 are arranged between two balancing disks 8 on the first shaft element 2 .

The laminated cores 9 and the balancing discs 8 are clamped against the joining stop 7, with the second shaft element 3 being connected to the first shaft element 2 by a mechanical connection 10, which is designed as a bayonet lock, and the laminated cores 9 and the balancing discs 8 being clamped against the joining stop 7 tense. The second shaft element 3 forms a fit 11 with the area designed as a hollow shaft and the area of the first shaft element 2 in contact therewith, whereby a concentric alignment of the first shaft element 2 with the second shaft element 3 is made possible. The second shaft element 3 forms the second bearing seat 12 of the shaft 1 for mounting the stator in the electrical machine. Furthermore, the second shaft element 3 has an oil bore 6 and an interface 13 to a resolver rotor.

Reference List

1

Wave

2

first wave element

3

second wave element

4

first camp seat

5

external teeth

6

oil drilling

7

joining stop

8th

balancing disc

9

laminated core

10

mechanical connection

11

fit

12

second bearing seat

13

interface

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 102018204436 A1 [0004]
• JP2005184957A [0005]
• DE 102016211246 A1 [0006]
• DE 102019113596 A1 [0007]

Claims (10)

Rotor for an electrical machine having a shaft (1) with a first shaft element (2), the first shaft element (2) having a first bearing seat (4) of the shaft (1) and a joining stop (7), on the first shaft element (2) laminated cores (9) are joined against the joining stop (7), characterized in that a second shaft element (3) is connected to the first shaft element (2) by means of a mechanical connection (10), the second shaft element (3) the laminated core (9) braced against the joining stop (7) and has a second bearing seat (12) of the shaft (1). rotor after claim 1 , characterized in that the mechanical connection (10) is designed as a securing element, preferably as a pin or as a bayonet catch. rotor after the claims 1 or 2 , characterized in that the first shaft element (2) and / or the second shaft element (3) has an external toothing (5). Rotor according to one of the preceding claims, characterized in that the first shaft element (2) and/or the second shaft element (3) has a radial snug fit for a balancing disc (8) and/or the laminated core (9). Rotor according to one of the preceding claims, characterized in that the first shaft element (2) and/or the second shaft element (3) has an oil bore (6). Rotor according to one of the preceding claims, characterized in that the first shaft element (2) and/or the second shaft element (3) has balancing surfaces for removing and/or applying material. Rotor according to one of the preceding claims, characterized in that a spring element, preferably a disc spring, is braced with the laminated core (9). Rotor according to one of the preceding claims, characterized in that the first shaft element (2) and the second shaft element (3) have fits (11) for concentrically aligning the first shaft element (2) with the second shaft element (3). Electrical machine, characterized in that the electrical machine has a rotor according to one of the preceding claims. Method for producing a rotor, preferably according to one of the preceding claims, characterized in that laminated cores (9) are joined to a first shaft element (2), the laminated cores (9) being clamped axially, a second shaft element (3) being connected to the first Shaft element (2) is mechanically connected to brace the laminated core (9) against a joining stop (7) of the first shaft element (2).

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