WO2021047719A1

WO2021047719A1 - Drive train device, electric motor, and rotor

Info

Publication number: WO2021047719A1
Application number: PCT/DE2020/100741
Authority: WO
Inventors: Patrick Wisbar; Alexandre Fischer; Thomas Fritz
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2019-09-10
Filing date: 2020-08-25
Publication date: 2021-03-18
Also published as: DE102019124189A1

Abstract

The invention relates to a rotor (24) for an electric motor (10), said rotor comprising: a rotor carrier (28) which can be rotated about a rotational axis (14); and a rotor laminated core (26) which is connected to the rotor carrier (28) via a toothing, can be rotated about the rotational axis (14), and has at least one first and second rotor lamination (38, 38.1, 38.2) arranged axially adjacent to one another, a plurality of magnets (40) being inserted in a peripherally distributed manner in the first and second rotor laminations (38.1, 38.2) in an arrangement (42) of mutually corresponding magnets. The invention also relates to: an electric motor (10) for a drive train of a vehicle, said motor comprising a stator (12) and a rotor (24) which can be rotated relative to the stator (12); and a drive train device for a vehicle, said drive train device comprising a drive having an electric motor (10) for applying a drive torque to an output.

Description

Powertrain device, electric motor and rotor

The invention relates to a rotor according to the preamble of claim 1. Furthermore, the invention relates to an electric motor and a drive train device with an electric motor.

An electric motor is known, for example, from WO 2016/155718 A1. This describes an electric motor which has a rotor with a laminated rotor stack composed of several rotor laminations and a rotor carrier. The laminated rotor core is connected to the rotor arm via a cross interference fit and a tongue and groove connection. The laminated rotor core has two radially opposite springs which engage in respective grooves in the rotor arm. One of these two tongue and groove connections causes torque to be transmitted in the pushing direction and the other in the pulling direction.

The object of the present invention is to manufacture and build a rotor for an electric motor more cost-effectively and to make it more reliable and efficient. The torque ripple during operation of the rotor is intended to be reduced.

At least one of these objects is achieved by a rotor having the features according to claim 1. As a result, the magnet arrangement of the first rotor lamination can be rotated circumferentially with respect to the magnet arrangement of the second rotor lamination and this circumferential offset can be precisely set and unchanged via the first and second toothing. As a result, a reliable and constant reduction in torque ripple in the operation of the rotor can be realized. The rotor can be manufactured and assembled more cheaply. The rotor laminations do not heat up during assembly.

The rotor can be operated without current. The rotor lamination packet can have a plurality of rotor laminations axially lined up next to one another. The magnets can be permanent magnets. The permanent magnets can be constructed from rare earth material. The magnets can be introduced into the respective rotor lamination in a non-positive, positive and / or cohesive manner.

The first toothing can be arranged on an inner circumference of the first rotor lamination. The second toothing can be arranged on an inner circumference of the second rotor lamination.

In a preferred embodiment of the invention, the first toothing is designed as a radial projection on the first rotor lamination, which positively engages in a radial recess in the rotor carrier. The radial projection can be made in one piece with the first rotor lamination. The radial projection can be punched from the first rotor lamination.

In a special embodiment of the invention, the second toothing is designed as a radial projection on the second rotor lamination, which positively engages in a radial recess in the rotor arm. The radial projection can be made in one piece with the second rotor lamination. The radial projection can be stamped from the second rotor lamination.

In a further special embodiment of the invention, the first and / or second toothing causes a torque transmission between the rotor core and the rotor carrier. In this way, a cost-effective torque transmission can be implemented. In addition, the material stresses that occur during torque transmission are reduced and better distributed. The stability of the rotor is increased.

The magnetic field acting on the rotor from outside can be converted into a torque on the rotor core via the magnets. The torque can be transmitted to the rotor arm via the first and / or second toothing.

In a preferred embodiment, the first and second teeth are aligned in the axial direction with respect to the rotor arm and, when the rotor is assembled, cause the first and second rotor laminations to be positioned relative to one another and in each case relative to the rotor arm. This allows the rotor easier and faster to assemble and the alignment of the first and second rotor laminations can be adjusted more reliably.

In a special embodiment of the invention, the first rotor lamination has a total of two toothings, on the one hand the first toothing and a further toothing, both of which are offset from one another in a first circumferential direction by a first spacing angle and in an opposite second circumferential direction by a second different from the first spacing angle Distance angles are offset from one another on. As a result, incorrect alignment of the respective rotor lamination with respect to the rotor arm when it is attached to the rotor arm can be prevented during assembly.

In a further special embodiment of the invention, the second rotor lamination has a total of two toothings, on the one hand the second toothing and another toothing, both of which are offset from one another in a first circumferential direction by a first spacing angle and in an opposite second circumferential direction by a second different from the first spacing angle Distance angles are offset from one another on.

In a preferred embodiment of the invention, a difference between the first and second offset angles is less than 90 °, preferably less than 45 °, in particular less than 30 °. As a result, the torque ripple of the electric motor can be reduced while still providing a sufficient number of poles.

Furthermore, an electric motor for a drive train of a vehicle, having a stator and a rotor which is rotatable with respect to the stator and having at least one of the features specified above is proposed to solve at least one of the aforementioned objects.

The drive train can be a hybrid drive train. The electric motor can produce a drive torque for moving the vehicle. A further drive element can alternatively or additionally produce a further drive torque. The further drive element can be an internal combustion engine. The electric motor can be a permanent magnet synchronous motor. The stator can convert the electrical energy introduced via the motor phase lines into a magnetic field acting on the rotor.

Furthermore, to solve at least one of the above objects, a drive train device for a vehicle, having a drive with a

Proposed electric motor with at least one of the features specified above for effecting a drive torque on an output.

The output can be a differential gear, a vehicle axle and / or a vehicle wheel. Further advantages and advantageous configurations of the invention emerge from the description of the figures and the illustrations.

The invention is described in detail below with reference to the figures. They show in detail:

Figure 1: A three-dimensional view of an electric motor in a special embodiment of the invention.

FIG. 2: A cross section through the electric motor from FIG. 1. FIG. 3: A three-dimensional view of a laminated rotor core of a rotor in a special embodiment of the invention.

FIG. 4: The detail A from FIG. 3 in an enlarged illustration. FIG. 5: A cross section through a rotor in a further special embodiment of the invention.

FIG. 1 shows a three-dimensional view of an electric motor 10 in a special embodiment of the invention. The electric motor 10 is designed as a permanent-magnet synchronous motor and has a stator 12 and a rotor arranged radially inside of the stator 12 so as to be rotatable about an axis of rotation 14. The rotor is non-rotatably connected to a motor shaft 16. The motor shaft 16 has a

Toothing 18 for connection to a connection component for transmitting the drive torque coming from the rotor. The stator 12 is supplied with electrical energy via three motor phase lines 20. In the stator 12, a plurality of coils constructed by wire winding are arranged, via which the electrical energy is converted into a magnetic field acting on the rotor. The resulting thermal energy during operation of the electric motor 10 is dissipated via a motor cooling system.

FIG. 2 shows a cross section through the electric motor 10 from FIG. The stator 12 comprises several coils 22 for converting the electrical energy into an electromagnetic rotating field on the rotor 24 arranged radially inside of the stator 12. The rotor 24 is constructed from a rotor core 26 and a rotor carrier 28 connected to the rotor core 26 in a rotationally fixed manner. The rotor arm 28 is connected to the motor shaft 16 in a rotationally fixed manner, in particular made in one piece.

The electric motor 10 is designed as an internal rotor and has a motor flange 30 for attachment to a receiving component for receiving the electric motor 10. The motor flange 30 is screwed to the stator 12 and receives a first bearing 32, here a roller bearing, on an inner circumference, through which the rotor arm 28 is mounted. Another bearing 34, here a roller bearing, is arranged on a side opposite the motor flange 30 between the rotor carrier 28 and a motor cover 36 screwed to the stator 12. The rotor arm 28 is supported radially and axially with respect to the stator 12 by the first and second bearings 32, 34.

The laminated rotor core 26, which is rotatable about the axis of rotation 14, comprises a plurality of laminated rotor laminations 38 which are arranged axially next to one another and which are connected to the rotor carrier 28 in a rotationally fixed manner via a toothing. The rotor laminations 38 are received on the rotor arm 28 on a section located axially between the first and second bearings 32, 34.

FIG. 3 shows a three-dimensional view of a laminated rotor core 26 of a rotor 24 in a special embodiment of the invention. The three rotor laminations 38 arranged axially next to one another are in an installation position as if the toothing with the rotor arm, not shown here, had been implemented in a form-fitting manner. A plurality of magnets 40 are introduced into the rotor laminations 38, distributed around the circumference, in a magnet arrangement 42 corresponding to one another. The magnets 40 are arranged in respective magnet recesses 44 in the respective rotor lamination 38. The magnets 40 can be introduced into the respective magnet recess 44 in a non-positive, positive and / or cohesive manner. The magnets 40 can be permanent magnets, for example made of rare earth material. Each of the magnets 40 in a rotor lamination 38 is arranged at a circumferential distance from the adjacent magnet 40.

A first rotor lamination 38.1 has, at a first circumferential position P1 rotated with a first offset angle relative to the magnet arrangement 42, a first toothing Z1 for a form-fitting connection with the rotor arm. A second rotor lamination 38.2 has, at a second circumferential position P2 rotated with a second offset angle relative to the magnet arrangement 42, a second toothing Z2 for a form-fitting connection with the rotor arm. The first and second circumferential positions P1, P2 are identical with respect to the rotor arm and are aligned in the axial direction, that is, parallel to the axis of rotation 14.

The first and second offset angles, however, are different for the mutually rotated alignment of the magnet arrangements 42 of the first and second rotor lamination 38.1, 38.2. As a result, the magnet arrangement 42 of the first rotor lamination 38.1 can be offset circumferentially with respect to the magnet arrangement 41 of the second rotor lamination 38.2 and this offset can be precisely set and unchanged via the first and second teeth Z1, Z2. As a result, a reliable and constant reduction in the torque ripple in the operation of the rotor 24 can be realized. The rotor 24 can be manufactured and assembled more cheaply. The rotor laminations 38 cannot be heated during assembly.

The first toothing Z1 is arranged on an inner circumference of the first rotor lamination 38.1 and the second toothing Z2 is arranged on an inner circumference of the second rotor lamination 38.2. The teeth Z1, Z2 are made in one piece from the respective rotor sheet 38.1, 38.2 as a radial projection. The radial projection is form-fitting with a corresponding radial recess in the rotor arm for torque transmission between the rotor core 26 and the rotor arm connectable. As a result, a more cost-effective torque transmission can be implemented. In addition, the material stresses occurring in the transmission of torque in the laminated rotor core 26 are reduced and better distributed. The stability of the rotor 24 is increased.

In Figure 4, the detail A from Figure 3 is shown in an enlarged view. The first rotor lamination 38.1 has a total of two circumferentially offset toothings, on the one hand the first toothing Z1 and another toothing Zn opposite second circumferential direction R2 offset from one another by a second spacing angle WA2 different from the first spacing angle WA1.

In this way, when assembling the laminated rotor core, incorrect alignment of the respective laminated rotor 38 with respect to the rotor carrier can be prevented. In the circumferential direction, the rotor lamination 38 can only assume the position predetermined by the first and further toothing Z1, Zn.

FIG. 5 shows a cross section through a rotor 24 in a further special embodiment of the invention. The rotor 24 is set up by the laminated rotor core 26 attached to the rotor carrier 28 to transmit the torque triggered by the magnets 40 to a motor shaft. The first rotor lamination 38.1 is connected to the rotor carrier 28 in a form-fitting and rotationally fixed manner via the first toothing Z1 and the further toothing Zn.

The first toothing Z1 of the first rotor lamination 38.1 is rotated via the first offset angle W1 with respect to the magnet arrangement 42 of the first rotor lamination 38.1 and is arranged at the first circumferential position P1. The second toothing Z2 of the second rotor lamination 38.2 shown in dashed lines is rotated via the second offset angle W2 with respect to the magnet arrangement 42 of the second rotor lamination 38.2 and is arranged at the second circumferential position P2. The first and second circumferential positions P1, P2 are the same with respect to the rotor arm 28 and are aligned in the axial direction. The first and second offset angles W1, W2, however, are different for the mutually rotated alignment of the magnet arrangements 42 of the first and second rotor lamination 38.1, 38.2. The first toothing Z1 is arranged on an inner circumference of the first rotor lamination 38.1 and the second toothing Z2 is arranged on an inner circumference of the second rotor lamination 38.2. The teeth Z1, Z2 are made in one piece from the respective rotor lamination 38.1, 38.2 as a radial projection and are positively received in an axially continuous radial recess 46 in the rotor carrier 28.

List of reference symbols

10 electric motor 12 stator 14 axis of rotation

16 motor shaft 18 toothing 20 motor phase line 22 coil 24 rotor

26 Laminated rotor core 28 Rotor arm 30 Motor flange 32 Bearing 34 Bearing

36 Motor cover 38 Rotor sheet

38.1 first rotor lamination

38.2 second rotor sheet 40 magnet

42 Magnet arrangement 44 Magnet recess 46 Recess P1 first circumferential position

P2 second circumferential position R1 first circumferential direction R2 second circumferential direction W1 first offset angle

W2 second offset angle

WA1 first spacing angle

WA2 second spacing angle Z1 first toothing Z2 second toothing

Zn further teeth

Claims

1. Rotor (24) for an electric motor (10), comprising a rotor arm (28) which can be rotated about an axis of rotation (14) and a rotor arm (28) connected to the rotor arm (28) via a toothing and around the

Axis of rotation (14) rotatable rotor lamination stack (26) with at least one first and second rotor lamination (38, 38.1, 38.2) arranged axially next to one another, wherein in the first and second rotor lamination (38.1, 38.2) several magnets (40) in a mutually corresponding magnet arrangement ( 42) are introduced distributed circumferentially, characterized in that the first rotor plate (38.1) has a first toothing (Z1) for a form-fitting connection with the first circumferential position (P1) at a first circumferential position (P1) rotated with a first offset angle (W1) relative to the magnet arrangement (42) The rotor arm (28) and the second rotor lamination (38.2) have a second toothing (Z2) for a positive connection with the rotor arm (28) at a second circumferential position (P2) rotated circumferentially with a second offset angle (W2) relative to the magnet arrangement (42), wherein the first and second circumferential position (P1, P2) with respect to the rotor arm (28) equal and the first and second offset angles (W1, W2) to r mutually rotated alignment of the magnet arrangements (42) of the first and second rotor lamination (38.1, 38.2) are different.

2. Rotor (24) according to claim 1, characterized in that the first toothing (Z1) is designed as a radial projection on the first rotor plate (38.1) which positively engages in a radial recess (46) in the rotor carrier (28) .

3. rotor (24) according to claim 1 or 2, characterized in that the second toothing (Z2) as a radial projection on the second rotor plate (38.2), which engages positively in a radial recess (46) in the rotor arm (28).

4. rotor (24) according to any one of the preceding claims, characterized in that the first and / or second toothing (Z1, Z2) causes a torque transmission between the rotor core (26) and the rotor carrier (28).

5. Rotor (24) according to one of the preceding claims, characterized in that the first and second teeth (Z1, Z2) are aligned in the axial direction with respect to the rotor carrier (28) and a positioning when assembling the rotor (24) of the first and second rotor lamination (38.1, 38.2) to one another and in each case to the rotor arm (28).

6. rotor (24) according to any one of the preceding claims, characterized in that the first rotor plate (38.1) has a total of two toothings, on the one hand the first toothing (Z1) and a further toothing (Zn), both in a first circumferential direction (R1 ) are offset from one another by a first spacing angle (WA1) and offset from one another in an opposite second circumferential direction (R2) by a second spacing angle (WA2) different from the first spacing angle (WA1).

7. Rotor (24) according to one of the preceding claims, characterized in that the second rotor plate (38.2) has a total of two toothings, on the one hand the second toothing (Z2) and another toothing (Zn), both in a first circumferential direction (R1 ) are offset from one another by a first spacing angle (WA1) and offset from one another in an opposite second circumferential direction (R2) by a second spacing angle (WA2) different from the first spacing angle (WA1).

8. rotor (24) according to claim 6 or 7, characterized in that a difference between the first and second offset angle (WA1, WA2) is less than 90 °.

9. Electric motor (10) for a drive train of a vehicle, comprising a stator (12) and a rotor (24) rotatable with respect to the stator (12) according to one of the preceding claims.

10. Drive train device for a vehicle, comprising a drive with an electric motor (10) according to claim 9 for effecting a drive torque on an output.