Rotary electric machine, and rotor of rotary electric machine

Abstract

The present invention is a rotary electric machine comprising a magnet, and a rotor core having a magnet hole into which the magnet is inserted. The magnet includes first magnets, and second magnets arranged in a V-shape radially inward of the first magnets. The rotor core includes a flux barrier formed facing a side surface on the radially outward side in the second magnet, a bridge formed between the second magnet and the flux barrier, and a second groove formed so that at least a part of the outer peripheral surface of the rotor core faces the side surface on the radially outward side of the second magnet.

Description

Rotating electric machines, rotors of rotating electric machines

[0001] The present invention relates to a rotating electric machine and a rotor for the rotating electric machine.

[0002] In the rotor structure of a rotating electric machine such as a motor or generator, for example, Patent Document 1 listed below discloses a configuration in which grooves are arranged on the outer peripheral surface between a tangent line 1 and a reference line in order to reduce torque ripple.

[0003] International Publication No. 2019 / 215853

[0004] Because there is a trade-off between maximum torque and torque ripple, conventionally, there has been a problem in that it is not possible to reduce torque ripple while maintaining maximum torque. In view of this, an object of the present invention is to provide a rotating electric machine and a rotor for the rotating electric machine in which torque ripple is reduced while maintaining torque.

[0005] A rotating electric machine comprising a magnet and a rotor core having a magnet hole into which the magnet is inserted, wherein the magnet includes a first magnet and a second magnet arranged in a V-shape radially inward from the first magnet, and the rotor core has a flux barrier formed opposite the radially outer side surface of the second magnet, a bridge formed between the second magnet and the flux barrier, and a second groove formed on the outer surface of the rotor core, at least a portion of which faces the radially outer side surface of the second magnet.

[0006] According to the present invention, it is possible to provide a rotating electric machine and a rotor for the rotating electric machine in which torque ripple is reduced while torque is maintained.

[0007] 1 is a cross-sectional view of a rotor and a stator of a rotating electric machine; FIG. 2 is a diagram illustrating the structure of a rotor of a rotating electric machine according to an embodiment of the present invention; FIG. 3 is a diagram illustrating the structure of a rotor of a rotating electric machine according to an embodiment of the present invention;

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0009] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0010] (One embodiment and overall configuration) (Fig. 1) A rotating electric machine 1 has a stator core 2 and a rotor core 3. The rotor core 3 has a plurality of magnets 20 inserted into magnet holes.

[0011] (FIGS. 2 and 3) As shown in FIG. 2, the magnets 20 (FIG. 1) inserted into the multiple magnet holes 9 of the rotor core 3 include a first magnet 21 and a second magnet 22. The first magnets 21 are arranged side by side in a V-shape in the circumferential direction, with the d-axis sandwiched between them. The second magnets 22 are arranged radially inward of the first magnets 21, also in a V-shape, with the d-axis sandwiched between them.

[0012] The rotor core 3 has a first groove 4a and a second groove 4b on the outer peripheral surface 4 of the rotor core. The first groove 4a is formed on the outer peripheral surface facing a radially outer main surface 21a of the first magnet 21. The second groove 4b is formed on the outer peripheral surface 4 of the rotor core 3 so that at least a portion of it faces a radially outer side surface 22a of the second magnet 22.

[0013] The rotor core 3 also has a flux barrier 5 and a bridge 6. The flux barrier 5 faces the radially outer side surface 22a of the second magnet 22 and is formed between the second magnet 22 and the outer peripheral surface 4. The bridge 6 is formed between the second magnet 22 and the flux barrier 5. As a result, the flux barrier 5 and the magnet hole into which the second magnet 22 is inserted are not connected, and are structured to be independent of each other.

[0014] 3 , the second groove 4b is formed on the q-axis side with reference to an imaginary line 8 connecting the corner 22b of the second magnet 22 that is closest to the outer peripheral surface 4 and the center of the rotor core 3. Furthermore, the innermost peripheral portion 14 of the second groove 4b is either coaxial with the outermost peripheral portion of the flux barrier 5 or is located radially inward of the outermost peripheral portion of the flux barrier 5.

[0015] With this structure, the magnetic path between the first groove 4a and the first magnet 21 is narrower than before, making it easier for magnetic flux to flow from the rotor core 3 to the stator core 2 in the air gap between the rotor core 3 and the stator core 2, thereby increasing torque. Similarly, the magnetic path between the second groove 4b and the flux barrier 5 is shifted toward the inner diameter halfway through, making it easier for magnetic flux to flow from the rotor core 3 to the stator core 2 in the air gap between the rotor core 3 and the stator core 2, thereby increasing torque.

[0016] On the other hand, in the portion where the second grooves 4b are provided, it is difficult for magnetic flux to flow from the rotor core 3 to the stator core 2, and torque ripple can be reduced by controlling the level of magnetic flux density at each rotational position of the rotor core 3. Therefore, torque ripple can be reduced while torque is increased.

[0017] It is also possible to adopt a shape that does not include the first groove 4a, and by positioning the second groove 4b closer to the q-axis than the imaginary line 8, it is possible to increase torque while suppressing torque ripple.

[0018] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0019] (1) A rotating electric machine 1 including a magnet 20 and a rotor core 3 having a magnet hole 9 into which the magnet 20 is inserted, wherein the magnet 20 includes a first magnet 21 and a second magnet 22 arranged in a V-shape radially inward of the first magnet 21, and the rotor core 3 has a flux barrier 5 formed facing a radially outer side surface of the second magnet 22, a bridge 6 formed between the second magnet 22 and the flux barrier 5, and a second groove 4b formed on the outer peripheral surface of the rotor core 3, at least a portion of which faces the radially outer side surface of the second magnet 22. By doing so, a rotating electric machine 1 can be provided in which torque ripple is reduced while torque is maintained.

[0020] (2) The innermost portion 14 of the second groove 4b is located at the same radial position as the outermost portion of the flux barrier 5, or is located radially inward of the outermost portion of the flux barrier 5. This arrangement makes it possible to reduce torque ripple while maintaining torque.

[0021] (3) The rotor core 3 has the first grooves 4a formed on the outer peripheral surface thereof so as to face the radially outer main surface 21a of the first magnet 21. This configuration makes it possible to reduce torque ripple while maintaining torque.

[0022] (4) The second groove 4b is formed on the q-axis side with respect to the imaginary line 8 that connects the corner 22b of the second magnet 22 that is closest to the outer circumferential surface and the center of the rotor core 3. This makes it possible to reduce torque ripple while maintaining torque.

[0023] (5) The rotating electrical machine 1 has a rotor that employs the above-described configuration. In this way, it is possible to provide a rotor for the rotating electrical machine 1 that reduces torque ripple while maintaining torque.

[0024] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0025] REFERENCE SIGNS LIST 1 Rotating electric machine 2 Stator core 3 Rotor core 4 Rotor core outer circumferential surface 4a First groove 4b Second groove 5 Flux barrier 6 Bridge 8 Virtual line 9 Magnet hole 14 Innermost peripheral portion of second groove 20 Magnet 21 First magnet 21a First magnet main surface 22 Second magnet 22a Second magnet side surface 22b Corner of second magnet closest to outer circumferential surface

Claims

1. A rotating electric machine comprising a magnet and a rotor core having a magnet hole into which the magnet is inserted, wherein the magnet includes a first magnet and a second magnet arranged in a V-shape radially inward from the first magnet, and the rotor core has a flux barrier formed facing the radially outer side surface of the second magnet, a bridge formed between the second magnet and the flux barrier, and a second groove formed on the outer surface of the rotor core, at least a portion of which faces the radially outer side surface of the second magnet.

2. A rotating electric machine as claimed in claim 1, wherein the second groove has an innermost portion located at the innermost circumference, which is either radially co-located with an outermost portion located at the outermost circumference of the flux barrier, or is radially inward of the outermost portion of the flux barrier.

3. A rotating electric machine according to claim 1, wherein the rotor core has a first groove formed on the outer circumferential surface thereof so as to face the radially outer principal surface of the first magnet.

4. A rotating electric machine according to claim 1, wherein the second groove is formed on the q-axis side with respect to a virtual line connecting the corner of the second magnet closest to the outer circumferential surface and the center of the rotor core.

5. A rotor for a rotating electric machine provided in the rotating electric machine according to claim 1.

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