ELECTRIC MOTOR, DRIVE ASSEMBLY AND ELECTROMECHANICAL BRAKE DEVICE

Abstract

An electric motor, in particular for an electromechanical brake device of a vehicle, includes a stator and a multi-pole rotor with an odd number of rotor poles. Recesses are defined in the central region of the rotor poles, drive assembly, and electromechanical brake device for a vehicle.

Claims

1. An electric motor comprising a stator and a multi-pole rotor with an odd number of rotor poles, wherein recesses are defined in the central region of the rotor poles.

2. The electric motor according to claim 1, wherein the recesses are formed and/or arranged in such a way that the magnetic field, is influenced and/or modified.

3. The electric motor according to claim 1 wherein the stator is designed as a permanently magnetic stator, and the stator has at least two opposite magnet poles.

4. The electric motor according to claim 1, wherein a cylindrical air gap is formed between the stator and the rotor.

5. The electric motor according to claim 1, wherein the rotor is arranged rotatably inside the stator.

6. The electric motor according to claim 1 wherein the rotor poles are designed so that they are T-shaped and/or anchor-shaped.

7. The electric motor according to claim 6, wherein the rotor poles have T side arms having a curved design.

8. The electric motor according to claim 1, wherein the rotor poles are spaced apart from one another circumferentially and an in particular axially continuous groove is formed between in each case two adjacent rotor poles.

9. The electric motor according to claim 1, wherein the rotor poles each have a core section situated radially on the inside with coil windings and/or a coil.

10. The electric motor according to claim 1, wherein the recesses are formed so that they are axially continuous.

11. The electric motor according to claim 1, wherein the recesses are formed as grooves or slots.

12. The electric motor according to claim 1, wherein the recesses are formed so that they are at least in some places essentially rectangular, triangular, or curved in cross-section.

13. The electric motor according to claim 1, wherein each recess is arranged between the two edges of the respective core section of the rotor pole.

14. The electric motor according to claim 1, wherein each recess is arranged centrally relative to the respective core section of the rotor pole.

15. The electric motor according to claim 1, wherein the recesses are arranged radially on the outside of the core sections of the rotor poles.

16. The electric motor according to claim 1, wherein the recesses extend radially inwards, starting from the outer circumference of the rotor poles.

17. The electric motor according to claim 1, wherein the recesses are open in the axial direction and/or open radially to the outside.

18. The electric motor according to claim 1, wherein the recesses and the grooves formed between adjacent rotor poles are arranged essentially opposite one another in the radial direction.

19. The electric motor according to claim 1, wherein the number of recesses corresponds to the number of rotor poles and/or each rotor pole. has in particular exactly and/or only one recess in its central region.

20. The electric motor according to claim 1, wherein the rotor and/or the rotor poles have at least one lamination stack consisting of layers of laminations or are produced therefrom.

21-26. (canceled)

Description

BRIEF DESCRIPTION OF DRAWINGS

[0027] Exemplary arrangements of the disclosure are described in detail below with reference to the drawings, in which, schematically and by way of example:

[0028] FIG. 1 shows a known electric motor with three different rotor positions;

[0029] FIG. 2 shows the magnetic field at a rotor pole of the electric motor according to FIG. 1;

[0030] FIG. 3 shows an electric motor according to a variant of the present disclosure with three different rotor positions;

[0031] FIG. 4 shows a rotor pole of the electric motor according to FIG. 3 with a variant of the recess and, schematically, the magnetic field which is formed; and

[0032] FIG. 5 shows a rotor pole of the electric motor according to FIG. 3 with a further variant of the recess and, schematically, the magnetic field which is formed.

DETAILED DESCRIPTION

[0033] FIG. 1 shows schematically a known electric motor 1 with three different rotor positions in which in each case attraction and/or repulsion take place. The electric motor 1 has a permanently magnetic stator 2 with a permanent magnet ring 3 with a positive pole 4 and a negative pole 5.

[0034] The electric motor 1 moreover has a rotor 6 arranged rotatably inside the stator 2. The rotor 6 has three T-shaped rotor poles 7 with coils 8. An air gap 9 is formed between the rotor 6 and the stator 2. The rotor 6 moreover has an odd number of grooves 10, in this case three grooves 10, or of rotor poles 7, in this case three rotor poles 7, each with one coil 8.

[0035] The magnetic force in the air gap 9 can increase significantly when the front edge of the coil core of a rotor pole 7 enters the magnetic field of one of the magnet poles 4, 5. The magnetic force differs significantly at the opposite side of the rotor. As a result, a vibration-exciting bending torque is generated which makes the rotor vibrate and causes undesired noises.

[0036] FIG. 2 shows schematically the magnetic field which is formed at a rotor pole 7 of the electric motor 1 according to FIG. 1.

[0037] At the edge of the rotor pole 7 and also of the magnet 3, the field lines run not only in a radial direction but also have tangential components. As the rotor 6 continues to rotate, the magnetic force in the air gap 9 between the magnet 3 and the coil core continues to increase. However, the tangential force component decreases markedly because the field lines run largely parallel in a radial direction inside the magnet 3 and also the central region of the T-shaped rotor pole 7.

[0038] FIG. 3 shows an electric motor 11 according to a variant of the present disclosure with three different rotor positions, in which in each case the attraction and repulsion essentially cancel each other out and hence vibration-exciting bending torques are prevented or at least significantly reduced.

[0039] The electric motor 11 has a permanently magnetic stator 12 with a permanent magnet ring 13 with a positive pole 14 and a negative pole 15. The positive pole 14 and the negative pole 15 are arranged radially opposite each other.

[0040] The electric motor 11 moreover has a rotor 16 arranged rotatably about an axis of rotation 22 inside the stator 12. The rotor 16 has three T-shaped rotor poles 17 with coils 18. A cylindrical air gap 19 is formed between the rotor 16 and the stator 12. The rotor 16 moreover has an odd number of grooves 20, in this case three grooves 20, or rotor poles 17, in this case three rotor poles 17, each with one coil 18.

[0041] The rotor poles 17 each have a core section 21 situated radially on the inside and T side arms arranged radially on the inside, attached to the latter and curved circumferentially. The coils 18 have coil windings which are wound about the core sections 21. The rotor poles 17 or their T side arms 22 are spaced apart circumferentially, wherein the groove 20 is formed between in each case two adjacent rotor poles 17 or T side arms 22. The grooves 20 are formed so that they are axially continuous.

[0042] Recesses 25 are defined in the central region 24 of the rotor poles 17. Each recess 25 is arranged circumferentially between the two edges of the respective core section 21 of the rotor pole 17 and centrally with respect to the respective core section 21 of the rotor pole 17. The recesses are formed as axially continuous grooves and arranged radially on the outside of the core sections 21 of the rotor poles 17. Moreover, the recesses 25 extend radially inwards, starting from the outer circumference of the rotor poles 17, and are open radially to the outside in the axial direction.

[0043] Each recess 25 and a groove 20 formed between adjacent rotor poles 17 or T side arms 22 are arranged essentially opposite one another in the radial direction or diametrically opposite. The number of recesses 25 therefore corresponds to the number of rotor poles 17 and the number of grooves 20. In particular, there is an odd number, such as 3, 5 or more. In the present exemplary arrangement according to FIG. 3, three recesses 25, three rotor poles 17 and three grooves 20 are defined. Each rotor pole 17 thus has exactly and only one recess 25 in its central region.

[0044] The recesses 25 are formed and arranged in such a way that the magnetic field, in particular the flux and/or the field line pattern of the magnetic field, is influenced or modified. As a result, when they enter the magnetic field, a magnetic force in the opposite direction is generated at the opposite recess 25 such that the resulting total force and hence also the vibration-exciting bending torque is reduced.

[0045] FIG. 4 shows schematically the magnetic field which is formed at a rotor pole 17 of the electric motor 11 according to FIG. 3 with a variant of the recess 25.

[0046] The recess 25 is here formed as a groove which is rectangular in cross-section.

[0047] By virtue of the recess 25, the magnetic flux and hence also the local magnetic force density can be modified, for example reduced. The magnetic force in the air gap can therefore initially decrease when the recess 25 enters the magnetic field. The magnetic flux can be higher again on the rear side of the recess 25. The magnetic force in the air gap 19 can therefore increase again after the recess 25 enters the magnetic field.

[0048] Otherwise, for further information reference should be made in particular to FIG. 3 and the associated description.

[0049] FIG. 5 shows schematically the magnetic field which is formed at a rotor pole 17 of the electric motor 11 according to FIG. 3 with a different variant of the recess 25.

[0050] The recess 25 is here formed with an essentially triangular cross-section.

[0051] Otherwise, for further information reference should be made in particular to FIGS. 3 and 4 and the associated description.

[0052] In particular, optional features of the disclosure are designated by “can”. Therefore, there are also developments and/or exemplary arrangements of the disclosure which additionally or alternatively have the respective feature or the respective features.

[0053] Isolated features can as required, also be singled out from combinations of features disclosed in this document and, by breaking a structural and/or functional link which may exist between the features, be used in combination with other features in order to define the subject-matter of a claim.