PERMANENT MAGNET FOR A PERMANENT MAGNET MACHINE

Abstract

A permanent magnet for a permanent magnet machine, a permanent magnet machine, a method for manufacturing a permanent magnet for a permanent magnet machine, and a method for manufacturing a permanent magnet machine is provided. The permanent magnet includes a base body, and at least one first fixing protrusion for fixing the base body to a rotor of the permanent magnet machine, wherein the first fixing protrusion extends from a first side of the base body, and wherein the base body and the at least one first fixing protrusion are formed integrally as one-piece.

Claims

1. A permanent magnet machine, comprising: A rotor comprising of a plurality of rotor segments arranged adjacent to each other and in a circumferential direction of the rotor, each rotor segment comprising at least one groove which is provided on a circumferential inner surface of the rotor segment; and a plurality of permanent magnets fixed to the rotor segments, each permanent magnet including: a base body; at least one first fixing protrusion for fixing the base body to the outer rotor, the at least one first fixing protrusion extending from a first side of the base body; and at least one second fixing protrusion extending from the first side of the base body, wherein the at least one second fixing protrusion is arranged adjacent to the at least one first fixing protrusion on the first side of the base body; wherein the base body and the at least one first fixing protrusion are formed integrally as one-piece; wherein the at least one first fixing protrusion is formed in a cross-sectional view in a form of a first L-shape and the at least one second fixing protrusion is formed in a cross-sectional view in a form of a second L-shape that is different from the first L-shape; wherein the first fixing protrusion and the second fixing protrusion extend away from each other.

2. The permanent magnet machine according to claim 1, wherein the base body further comprises: a second side opposite the first side; a third side and a fourth side, each interconnecting the first side and the second side, and distanced to one another; wherein the permanent magnet further comprises: at least one third fixing protrusion extending from the third side, and/or at least one fourth fixing protrusion extending from the fourth side.

3. The permanent magnet machine according to claim 1, wherein the permanent magnet is uncoated.

4. The permanent magnet machine according to claim 1, wherein the permanent magnet is unmachined and/or ungrinded.

5. The permanent magnet machine according to claim 1, wherein the at least one groove is formed such that a shape of the at least one groove corresponds to a shape of the at least one first fixing protrusion, further wherein the at least one first fixing protrusion is coupled to the at least one groove.

6. The permanent magnet machine according to claim 1, wherein the permanent magnet is fixed to the rotor such that the permanent magnet and the rotor are unmoveable with respect to each other.

7. The permanent magnet machine according to claim 1, wherein the rotor is an outer rotor.

8. A method comprising: arranging a plurality of rotor segments adjacent to each other and in a circumferential direction, each rotor segment comprising at least one groove which is provided on a circumferential inner surface of the rotor segment; and coupling a permanent magnet to each rotor segment, wherein the permanent magnet includes: a base body; at least one first fixing protrusion for fixing the base body to the outer rotor, the at least one first fixing protrusion extending from a first side of the base body; and at least one second fixing protrusion extending from the first side of the base body, wherein the at least one second fixing protrusion is arranged adjacent to the at least one first fixing protrusion on the first side of the base body; wherein the base body and the at least one first fixing protrusion are formed integrally as one-piece; wherein the at least one first fixing protrusion is formed in a cross-sectional view in a form of a first L-shape and the at least one second fixing protrusion is formed in a cross-sectional view in a form of a second L-shape that is different from the first L-shape; wherein the first fixing protrusion and the second fixing protrusion extend away from each other.

9. The method according to claim 8, wherein the base body and the at least one first fixing protrusion are formed in one common process step.

10. The method according to claim 8, wherein the permanent magnet is formed uncoated.

11. The method according to claim 8, wherein the permanent magnet is formed unmachined and/or ungrinded.

12. The method according to claim 8, further comprising after coupling the permanent magnet into the rotor segment, providing an extra layer of coating or spray coating to both the rotor segments and the permanent magnet.

Description

BRIEF DESCRIPTION

[0065] Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

[0066] FIG. 1 shows a cross-sectional view of a permanent magnet comprising one first fixing protrusion according to an exemplary embodiment;

[0067] FIG. 2 shows a cross-sectional view of a permanent magnet comprising two first fixing protrusions according to an exemplary embodiment;

[0068] FIG. 3 shows a cross-sectional view of a permanent magnet comprising one first fixing protrusion according to an exemplary embodiment;

[0069] FIG. 4 shows a cross-sectional view of a permanent magnet comprising three first fixing protrusions according to an exemplary embodiment;

[0070] FIG. 5 shows a cross-sectional view of a permanent magnet comprising one first fixing protrusion and one second fixing protrusion according to an exemplary embodiment;

[0071] FIG. 6 shows a cross-sectional view of a permanent magnet comprising one first fixing protrusion according to an exemplary embodiment;

[0072] FIG. 7 shows a cross-sectional view of a permanent magnet comprising one first fixing protrusion and one second fixing protrusion according to an exemplary embodiment;

[0073] FIG. 8 shows a cross-sectional view of a permanent magnet comprising one third fixing protrusion and one fourth fixing protrusion according to an exemplary embodiment;

[0074] FIG. 9 shows a side view of a permanent magnet comprising two first fixing protrusions according to an exemplary embodiment;

[0075] FIG. 10 shows a sectional view in the axial direction of a rotor before fixing the permanent magnet to the rotor according to an exemplary embodiment;

[0076] FIG. 11 shows a sectional view in the axial direction of a rotor after fixing permanent magnets to the rotor according to an exemplary embodiment;

[0077] FIG. 12 shows a side view of the base body after forming the base body according to an exemplary embodiment compared to a conventionally formed base body; and

[0078] FIG. 13 shows a sectional view in the axial direction of a current permanent magnet module according to the known art.

DETAILED DESCRIPTION

[0079] FIG. 1 shows a cross-sectional view of a permanent magnet 100 comprising one first fixing protrusion 121 according to an exemplary embodiment.

[0080] The permanent magnet 100 comprises a bread loaf shaped base body 110 and a rectangular shaped first fixing protrusion 121.

[0081] The first fixing protrusion 121 extends from the first side 111 of the base body 110 and is arranged in the middle of the base body seen in a first direction 131 corresponding to the circumferential direction of the rotor. It may be understood that the first fixing protrusion may also be arranged at any other circumferential position at the first side (not shown in FIG. 1).

[0082] In FIG. 1, the first side 111 is planar. However, it may be understood that the first side 111 may alternatively be curved. The exact shape of the first side 111 may be dependent on the one hand on the width of the base body 110 in the first direction and on the other hand on the shape of the rotor surface.

[0083] The width of the rectangular shaped first fixing protrusion 121 is larger than the height of the first fixing protrusion 121 which extends parallel to a second direction 132.

[0084] A second side 112 is opposite the first side 111 and a third side 113 and a fourth side 114 interconnect the first side 111 and the second side 112, and are distanced to each other. The second direction 132 is rectangular to the first direction 131 and is defined as extending from the first side 111 in the direction of the second side 112. A third direction 133 extends rectangular to the first direction 131 and the second direction 132.

[0085] Each of the first side 111, the second side 112, the third side 113 and the fourth side 114 may be shaped curved or planar depending on the given geometrical constraints or the required magnetic features.

[0086] The first protrusion 121 extends in the third direction 133 over the entire depth of the base body 110 seen in the third direction 133 (not shown in FIG. 1).

[0087] FIG. 2 shows a cross-sectional view of a permanent magnet 100 comprising two first fixing protrusions 121 according to an exemplary embodiment.

[0088] The permanent magnet 100 comprises a base body 110 which is shaped and formed identical to the base body 100 in FIG. 1, and two first fixing protrusions 121. The two first fixing protrusions 121 are distanced with respect to one another in the first direction 131. Each of the two first fixing protrusions 121 is shaped rectangular and has a smaller width compared to the one first fixing protrusion 121 in FIG. 1.

[0089] The width seen in the first direction 131 of the first fixing protrusion 121 is larger than the height of the first fixing protrusion 121 seen in the second direction 132. The two first fixing protrusions 121 are shaped and formed identical. It may be understood that the two first fixing protrusions may also be shaped and formed different from each other, for example dependent on different loads (not shown in FIG. 2).

[0090] Each of the two first protrusions 121 extends in the third direction 133 over the entire depth of the base body 110 seen in the third direction 133 (not shown in FIG. 2).

[0091] FIG. 3 shows a cross-sectional view of a permanent magnet 100 comprising one first fixing protrusion 121 according to an exemplary embodiment.

[0092] The permanent magnet 100 comprises a base body 110 and one first fixing protrusion 121. The first fixing protrusion 121 is arranged in the middle of base body 110 seen in the first direction 131. It may be understood that the first fixing protrusion may also be arranged at any other circumferential position at the first side (not shown in FIG. 3).

[0093] The first fixing protrusion 121 is rectangular shaped and has a width seen in the first direction 131 which is smaller than a height seen in the second direction 132. Hence, compared to the two first fixing protrusions 121 shown in FIG. 2, the first fixing protrusion 121 shown in FIG. 3 is a rectangle turned about 90°.

[0094] FIG. 4 shows a cross-sectional view of a permanent magnet 100 comprising three first fixing protrusions 121 according to an exemplary embodiment.

[0095] The permanent magnet 100 comprises the base body 110 and three first fixing protrusions 121 which are spaced apart from each other by an even distance in-between the different first fixing protrusions 121. It may be understood that distances between respective adjacent first fixing protrusions may also be uneven (not shown in FIG. 4). The second of the three first fixing protrusions 121 is arranged in the middle of the base body 110 seen in the first direction. The three first fixing protrusions 121 are shaped and formed identical. It may be understood that the second of the three first fixing protrusions 121 may also be arranged at any other circumferential position at the first side 111 and that the three first fixing protrusions 121 may also be shaped and formed different from each other (not shown in FIG. 4).

[0096] Each of the three first fixing protrusions 121 is shaped rectangular having a width in the first direction 131 which is smaller than a height in the second direction 132.

[0097] FIG. 5 shows a cross-sectional view of a permanent magnet 100 comprising one first fixing protrusion 121 and one second fixing protrusion 522 according to an exemplary embodiment.

[0098] The permanent magnet 100 comprises the base body 110 which is shaped and formed as the base body 110 shown in FIG. 1, the first fixing protrusion 121 and the second fixing protrusion 522.

[0099] The first fixing protrusion 121 and the second fixing protrusion 522 are each shaped as a parallelogram in the cross-sectional view. Therefore, the three-dimensional shape of the first fixing protrusion 121 and the second fixing protrusion 522 is a parallelepiped. The extension of the first fixing protrusion 121 and the extension of the second fixing protrusion 522 each have a component in the first direction 131 and a component in the second direction 132. Additionally, the first fixing protrusion 121 and the second fixing protrusion 522 extend pointing away from each other.

[0100] FIG. 6 shows a cross-sectional view of a permanent magnet 100 comprising one first fixing protrusion 121 according to an exemplary embodiment.

[0101] The permanent magnet 100 comprises the base body 110 which is formed and shaped identical to the base body 110 shown in FIG. 1, and one first fixing protrusion 121 which is T-shaped and arranged in the middle of the first side 111 seen in the first direction 131, and which extends from the first side 111. It may be understood that the one first fixing protrusion 121 may also be arranged at any other circumferential position at the first side 111 (not shown in FIG. 6).

[0102] The T-shaped first fixing protrusion 121 extends in the third direction 133 over the entire depth of the base body 110 seen in the third direction 133.

[0103] FIG. 7 shows a cross-sectional view of a permanent magnet 100 comprising one first fixing protrusion 121 and one second fixing protrusion 522 according to an exemplary embodiment.

[0104] The first fixing protrusion 121 and the second fixing protrusion 522 are both L-shaped in the cross-sectional view. The first fixing protrusion 121 is distanced from the second fixing protrusion 522. The middle of the distance between the first fixing protrusion 121 and the second fixing protrusion 522 seen in the first direction 131 coincidence with the middle of the base body 110 seen in the first direction 131. Therefore, each of the first fixing protrusion 121 and the second fixing protrusion 522 is spaced apart from the middle of the base body 110 in the first direction 131.

[0105] The longer leg of the L-shaped first fixing protrusion 121 and the second fixing protrusion 522 extends perpendicular to the first side 111 of the base body 110. The respective shorter leg of the first fixing protrusion 121 and the second fixing protrusion 522 extend away from each other and parallel to the first direction 131.

[0106] FIG. 8 shows a cross-sectional view of a permanent magnet 100 comprising one third fixing protrusion 823 and one fourth fixing protrusion 824 according to an exemplary embodiment.

[0107] The permanent magnet 100 comprises one third fixing protrusion 823, one fourth fixing protrusion 824, and the base body 110 which is formed and shaped as the base body 110 in FIG. 1. The third fixing protrusion 823 extends perpendicular to the third side 113, and the fourth fixing protrusion 824 extends perpendicular from the fourth side 114. Additionally, the third fixing protrusion 823 and the fourth fixing protrusion 824 are rectangular shaped.

[0108] Furthermore, there are no fixing protrusions provided at the first side 111 of the base body 110.

[0109] FIG. 9 shows a side view of a permanent magnet 100 comprising two first fixing protrusions 121 according to an exemplary embodiment. The side view is shown seen in the second direction 132 such that the first side 111 is shown as a plane.

[0110] The two first fixing protrusions 121 are distanced relative to each other in the third direction 133. Additionally, the two first fixing protrusions 121 each have a first fixing protrusion depth seen in the third direction 133 which is shorter than a main body depth seen in the third direction 133.

[0111] FIG. 10 shows a sectional view in the axial direction of an outer rotor 1000 before fixing the permanent magnet 100 to the rotor 1000 according to an exemplary embodiment.

[0112] The outer rotor 1000 comprises rotor segments 1010 which are arranged on adjacent and in touch to another in a circumferential direction of the rotor 1000.

[0113] Each rotor segment 1010 comprises a groove 1041 which is provided on a circumferential inner surface of the outer rotor segments 1010.

[0114] FIG. 11 shows a sectional view in the axial direction of a rotor 1000 after fixing permanent magnets 100 to the rotor 1000 according to an exemplary embodiment.

[0115] The rotor 1000 comprises outer rotor segments 1010 each having a groove 1041. One first fixing protrusion 121 is inserted in each of the grooves 1041 such that one permanent magnet 100 is fixed to each rotor segment 1010 by a press fit between the first fixing protrusion 121 and the groove 1041.

[0116] FIG. 12 shows a side view of the base body 110 after forming the base body 110 according to an exemplary embodiment compared to a conventionally formed base body 1210.

[0117] In FIG. 12 a conventional base body 1210 is depicted with a dashed line. In comparison, the base body 110 according to an exemplary embodiment is depicted with a continuous line. In an embodiment, the base body 110 is sintered and then unmachined and ungrinded as well as uncovered, in particular uncoated.

[0118] As may be seen from FIG. 12, the geometrical deviation on each of the first side 111, the second side 112, the third side 113 and the fourth side 114 compared to the four sides of the base body 1210 is small. In an embodiment, the geometric deviation is less than 0.3 mm.

[0119] The shrinkage rate could also be taken into account in the mould. Hence, the final magnet will shrink back to the desired size and shape.

[0120] Although the present invention has been disclosed in the form of embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

[0121] For the sake of clarity, it is to be understood that the use of ‘a’ or ‘an’ throughout this application does not exclude a plurality, and ‘comprising’ does not exclude other steps or elements.