Permanent magnet energized motor with rotatable bar magnets

Abstract

A rotor for an electrical machine includes a rotor body and an axis of revolution which extends in an axial direction and about which the rotor body is rotatable. The rotor further includes an outer casing surface which delimits the rotor body, at least one pole arrangement, and a movement mechanism for the at least one pole arrangement. The movement mechanism is designed such that the at least one pole arrangement is movable about a rotation axis which is oriented substantially parallel to the axis of revolution of the rotor. The at least one pole arrangement is also movable about the rotation axis in addition to rotation about the axis of revolution of the rotor.

Claims

1. A rotor for an electrical machine, comprising: a rotor body, an axis of revolution which extends in an axial direction and about which the rotor body is rotatable, an outer casing surface which delimits the rotor body, at least one pole arrangement configured to be movable about a rotation axis which is oriented substantially parallel to the axis of revolution of the rotor, wherein the at least one pole arrangement is also movable about the rotation axis in addition to rotation about the axis of revolution of the rotor, and wherein at least three pole arrangements have different distances from the outer casing surface of the rotor, wherein only two of the at least three pole arrangements with the smallest distance from the outer casing surface are moveable about a respective rotation axis.

2. The rotor as claimed in claim 1, wherein the at least one pole arrangement is movable between at least a first and a second adjustment position, wherein, in one adjustment position a distance between a first pole body element of the pole arrangement and the outer casing surface is less than the distance between a second pole body element of the pole arrangement and the outer casing surface.

3. The rotor as claimed in claim 1, wherein the at least one pole arrangement has a first pole and/or a second pole, and wherein the at least one pole arrangement comprises at least one magnetic pole body element.

4. The rotor as claimed in claim 1, wherein the at least one pole arrangement has a symmetrical shape, of which a geometric center and a center of mass coincide in order to allow rotation about the rotation axis, wherein the at least one pole arrangement is configured as a rotatable bar, wherein the at least one pole arrangement has a circular cross-sectional surface, wherein the at least one pole arrangement is formed from at least two pole body elements which each form half a shape of the at least one pole arrangement, and wherein the least three pole arrangements form a V-shaped arrangement or a spoke-like arrangement.

5. The rotor as claimed in claim 1, wherein the rotor comprises at least one magnetic flux block, wherein the at least one magnetic flux block is arranged between two pole arrangements, wherein the at least one magnetic flux block extends in a radial direction and/or in a circumferential direction.

6. An electrical machine comprising: a rotor and a stator surrounding the rotor, wherein the rotor and the stator are spaced apart from each other in a radial direction in order to form an air gap therebetween, wherein the electrical machine comprises an axis of revolution about which the rotor is rotatable, wherein the rotor has a rotor body and an outer casing surface which delimits the rotor, wherein the rotor comprises at least one pole arrangement, wherein the at least one pole arrangement comprises a magnetic and/or magnetizable pole, wherein the magnetic and/or magnetizable pole of the pole arrangement is formed so as to be rotatable relative to the stator and the rotor, and wherein at least three pole arrangements have different distances from the outer casing surface of the rotor, wherein only two of the at least three pole arrangements with the smallest distance from the outer casing surface are movable about a respective rotation axis.

7. The electrical machine as claimed in claim 6, wherein the stator comprises at least one stator pole arrangement for generating a magnetic field, wherein the at least one pole arrangement is movable between at least a first and a second adjustment position, wherein, in the first adjustment position, a first pole of the at least one pole arrangement is oriented towards the stator, wherein, in the second adjustment position, a second pole of the at least one pole arrangement is oriented towards the stator, and wherein, within a definable time interval, the at least one stator pole arrangement generates an electromagnetic counter-field to the electromagnetic field of the at least one pole arrangement of the rotor, in order to allow rotation of the pole arrangement according to forces produced by the electromagnetic fields, whereby the at least one pole arrangement can be rotated from the first adjustment position into the second adjustment position and then locked.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure is now explained in more detail below with reference to exemplary embodiments in conjunction with associated drawings. The drawings show diagrammatically:

(2) FIG. 1 a sectional view of a rotor according to the disclosure in a first exemplary embodiment;

(3) FIGS. 2 to 4 a sectional view of an electrical machine according to the disclosure in a first exemplary embodiment;

(4) FIG. 5 a sectional view of an electrical machine according to the disclosure in a second exemplary embodiment; and

(5) FIGS. 6 to 8 a sectional view of an electrical machine according to the disclosure in the first exemplary embodiment, with a rotor according to a second exemplary embodiment.

DETAILED DESCRIPTION

(6) In the description which follows, the same reference signs are used for the same objects.

(7) FIG. 1 shows a sectional view of a rotor 1 according to the disclosure in a first exemplary embodiment.

(8) More precisely, FIG. 1 shows a motor 1 of the electrical machine 20 formed as an internal rotor motor.

(9) The rotor 1 has a rotor body 10 and an axis of revolution D which extends in the axial direction and about which the rotor 1 or the rotor body 10 can be rotated.

(10) The rotor 1 furthermore has an outer casing surface AM which delimits the rotor 1 or the rotor body 10.

(11) The rotor 1 furthermore has various pole arrangements 2, 3, 4, 5, 6, 7, 8, 9, wherein each pole arrangement 2-9 has a magnetic pole N, S or a first pole N and a second pole S.

(12) Here, each pole arrangement 2-9 or each pole of the pole arrangements 2-9 is formed by a magnetic pole body element or a permanent magnet.

(13) According to FIG. 1, each pole arrangement 2-9 or its pole body element is formed as a bar and has a circular cross-sectional surface. The bar form extends in the direction of the axis of revolution D.

(14) Here, two pole body elements N, S in each case form a pole arrangement 2-9, wherein the pole body elements each form approximately half the shape of a pole arrangement 2-9.

(15) In other words, each pole arrangement 2-9 has a symmetrical shape, in which the geometric center and the center of mass coincide in order to allow rotation about a rotation axis of the respective pole arrangement.

(16) The rotation axis A is oriented substantially parallel to the axis of revolution D.

(17) The pole arrangements 2 to 5, and 6 to 9, each form a V-shaped arrangement wherein the pole arrangements 2/3 and 4/5, and 6/7 and 8/9, have different distances from the outer casing surface AM of the rotor 1.

(18) The pole arrangements 2, 5, 6, 9 are thus closer to the casing surface AM than the pole arrangements 3, 4, 7, 8.

(19) The rotor 1 also has a movement mechanism for the pole arrangements 2, 5, 6 and 9, wherein the movement mechanism is configured such that the pole arrangements 2, 5, 6 and 9 are movable about a rotation axis A which is oriented substantially parallel to the axis of revolution D of the rotor 1. In this way, pole arrangements 2, 5, 6, 9 are also movable or rotatable about their rotation axis A, in addition to the rotation about the axis of revolution D of the rotor 1.

(20) Again, expressed in other words, only the two pole arrangements 2, 5, or 6, 9 with the smallest distance from the outer casing surface AM are rotatable about their rotation axis A.

(21) Although not shown concretely, the movement mechanism however also comprises an actuator for moving the pole arrangements 2, 5, 6, 9, wherein the movement mechanism may comprise a hydraulically or pneumatically operable actuator, or an electrical actuator, in particular an electric motor.

(22) Also, the movement mechanism (not shown) is arranged between the axis of revolution D and a pole arrangement 2, 5, 6, 9 which is spaced from the axis of revolution D in the radial direction R. In this way, the centripetal acceleration on the movement mechanism can be kept low, whereby operation of the actuator requires less force in comparison with an arrangement of the movement mechanism between the casing surface AM and a pole arrangement 2, 5, 6, 9.

(23) Also, the movement mechanism is formed as a hollow cylinder, in order to receive the pole arrangements 2, 5, 6, 9 in its interior.

(24) Here, the movement mechanism has its own axis of revolution or rotation axis, wherein the movement mechanism is configured so as to be rotationally symmetrical to its rotation axis A.

(25) In concrete terms, the movement mechanism has a bearing unit via which the pole arrangements 2, 5, 6, 9 are freely rotatable. The bearing unit may be a roller bearing which receives the magnetic pole body elements of the pole arrangements 2, 5, 6, 9 in a rotatable fashion.

(26) In this context, the term “freely rotatable” means that the pole arrangements 2, 5, 6, 9 or their pole body elements can be twisted fully variably, so that continuous adjustment of the rotor 1 or an electrical machine 20 is possible.

(27) It is also possible to twist the pole arrangements 2, 5, 6, 9 or their pole body elements either all simultaneously or individually or in groups. The twist may thus take place either discretely (e.g. in precisely two positions) or be adjusted continuously or take place in defined intermediate steps. Maximum flexibility allows a correspondingly better controllability but also requires corresponding actuation.

(28) As an alternative to the actuator, the movement mechanism may comprise a lock (not shown) per pole arrangement 2, 5, 6 and 9, which is configured in the manner of an external brake and acts from the outside on the pole arrangements 2, 5, 6 and 9 in order to limit their movement.

(29) The lock comprises various adjustment positions, so that for example in one adjustment position, the distance between a first pole body element N of a pole arrangement 2, 5, 6, 9 and the outer casing surface AM is smaller than the distance between a second pole body element S of a pole arrangement 2, 5, 6, 9 and the outer casing surface AM.

(30) FIGS. 2 to 4 show a sectional view of an electrical machine 20 according to the disclosure in a first exemplary embodiment.

(31) The figure shows an electrical machine 20 with a rotor 1 as explained above, and a stator 21 surrounding the rotor 1.

(32) The rotor 1 and the stator 21 are spaced apart from each other in the radial direction R, in order to form an air gap between the two, wherein the electrical machine 20 comprises an axis of revolution D about which the rotor 1 can be rotated.

(33) Furthermore, as already known, the rotor 1 has a rotor body 10 and an outer casing surface AM which delimits the rotor 1 or rotor body 10.

(34) Furthermore, the rotor 1 comprises various pole arrangements 2-9 and a movement mechanism for the pole arrangement 2, 5, 6, 9, wherein each pole arrangement 2-9 comprises a magnetic pole N, S.

(35) Here too, the movement mechanism is configured such that the pole arrangements 2, 5, 6, 9 are movable about a rotation axis A of the movement mechanism which is oriented substantially parallel to the axis of revolution D of the rotor 1. In this way, the magnetic poles N, S of the pole arrangements 2, 5, 6, 9 are configured so as to be rotatable relative to the stator 21 and the rotor 1.

(36) Furthermore, FIG. 2 shows that the stator 21 comprises several stator pole arrangements 22 for generating a magnetic field.

(37) In the present exemplary embodiment, the movement mechanism has a lock for the pole arrangements 2, 5, 6, 9, wherein the lock comprises several adjustment positions.

(38) Here, the adjustment positions are shown with different orientations of the first pole N and hence also the second pole S of the pole arrangements 2, 5, 6, 9 to the stator 21 in FIGS. 2 to 4, and 6 to 8.

(39) In order to transfer the pole arrangements 2, 5, 6, 9 from one adjustment position to another, in operation of the electrical machine 20, within a defined time interval, several stator pole arrangements 22 generate an electromagnetic counter-field to the electromagnetic field of the pole arrangements 2, 5, 6, 9 of the rotor 1.

(40) In this way, e.g. after releasing the lock in a first adjustment position, the pole arrangements 2, 5, 6, 9 can be rotated according to the forces generated by the electromagnetic fields, whereby the pole arrangements 2, 5, 6, 9 can be rotated and then locked in the second adjustment position by means of the lock.

(41) FIG. 5 shows a sectional view of an electrical machine 20 according to the disclosure in a second exemplary embodiment.

(42) In a comparison of the electrical machines 20 in FIGS. 2 to 4 and that in FIG. 5, it is evident that in FIGS. 2 to 4, an indicated coil wire is wound around one stator tooth in each case.

(43) In the second exemplary embodiment in FIG. 5 however, the coil wire of the stator pole arrangement is wound around various stator teeth.

(44) FIGS. 6 to 8 show a sectional view of an electrical machine 20 according to the disclosure in the first exemplary embodiment, with a rotor 1 according to a second exemplary embodiment.

(45) In contrast to the rotor 1 in FIGS. 1 to 5, the rotor 1 in FIGS. 6 to 8 comprises a magnetic flux block S1, S2, S3 which is arranged between two pole arrangements 5, 6 or 4, 5, 6, 7.

(46) Here, the magnetic flux block S1 extends in the circumferential direction U, whereas the magnetic flux blocks S2, S3 extend in the radial direction R.

LIST OF REFERENCE SIGNS

(47) 1 Rotor 2 Pole arrangement 3 Pole arrangement 4 Pole arrangement 5 Pole arrangement 6 Pole arrangement 7 Pole arrangement 8 Pole arrangement 9 Pole arrangement 10 Rotor body 20 Electrical machine 21 Stator 22 Stator pole arrangement A Rotation axis of movement mechanism and rotation axis of a pole arrangement AM Outer casing surface D Axis of revolution N First/magnetic pole R Radial direction S Second/magnetic pole T Tangential direction U Circumferential direction X Axial direction