Rotor and generator having the same

Abstract

To provide a rotor that can be reduced in size while suppressing reduction in magnetic flux, and a generator including the same.SOLUTION: A rotator 30 includes a pair of first magnets 60a, 60b and a pair of second magnets 60c, 60d. The pair of first magnets 60a, 60b are disposed plane-symmetrically about a first plane and being located on one side of a central axis A in a first direction. Each of the first magnets extends so as to be located on a first plane side as it goes toward a one side in the first direction. Each of the first magnets is magnetized in an orthogonal direction orthogonal to an extending direction of the first magnet. The pair of second magnets 60c, 60d are disposed plane-symmetrically about a second plane with respect to the pair of first magnets 60a, 60b. A N-pole of each of the second magnets is located plane-symmetrically about the second plane with respect to a S-pole of the first magnet. The S-pole of each of the second magnets is located plane-symmetrically about the second plane with respect to the N-pole of the first magnet. A dimension of a rotator iron core 50 in a second direction is smaller than that in the first direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rotor and a generator including the rotor.

Background Art

[0002] Conventionally, a rotor having magnets is known. For example, Patent Document 1 discloses a rotor including at least two magnetic poles each formed of a pair of permanent magnets spaced apart in the angular direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] By the way, it is desired to miniaturize the rotor while suppressing reduction of magnetic flux.

[0005] Therefore, an object of the present invention is to provide a rotor that can be miniaturized while suppressing reduction of magnetic flux, and a generator including the rotor.

Means for Solving the Problems

[0006] (1) The rotor of the present invention includes a rotor core, a pair of first magnets accommodated in the rotor core, and a pair of second magnets accommodated in the rotor core. The pair of first magnets are arranged symmetrically with respect to a first plane including the central axis of the rotor core and including a first straight line orthogonal to the central axis. The pair of first magnets are located on one side of the central axis in a first direction in which the first straight line extends, and each of the first magnets extends so as to be located closer to the first plane as it faces one side in the first direction. Each of the first magnets is magnetized in a direction orthogonal to the central axis and the extending direction of the first magnet. The pair of second magnets are arranged symmetrically with respect to the pair of first magnets with respect to a second plane including the central axis and including a second straight line orthogonal to the central axis and the first straight line. The N pole of each of the second magnets is located symmetrically with respect to the S pole of the first magnet with respect to the second plane, and the S pole of each of the second magnets is located symmetrically with respect to the N pole of the first magnet with respect to the second plane. The rotor core has one or more first slits that extend so as to be located on one side in the first direction with respect to the first magnet on one side in a second direction in which the second straight line extends among the pair of first magnets and to be located closer to the first plane as it faces one side in the first direction, one or more second slits arranged symmetrically with respect to the one or more first slits with respect to the first plane, one or more third slits arranged symmetrically with respect to the one or more first slits with respect to the second plane, and one or more fourth slits arranged symmetrically with respect to the one or more second slits with respect to the second plane, and is characterized in that the dimension in the second direction is smaller than the dimension in the first direction.

[0007] (2) In the rotor of the above (1), the outer peripheral surface of the rotor core is located on one side in the first direction with respect to the one or more first slits and the one or more second slits, curved along the circumferential direction centered on the central axis, and symmetric with respect to the first plane. It has a first surface part, a second surface part arranged symmetrically with respect to the first surface part centered on the second plane, a third surface part located on one side in the second direction with respect to the second magnet on one side in the second direction among the first magnet and the pair of second magnets in the second direction, parallel to the first plane, and symmetric with respect to the second plane, a fourth surface part arranged symmetrically with respect to the third surface part centered on the first plane, a fifth surface part connected to the end on one side in the second direction of the first surface part and the end on one side in the first direction of the third surface part and located on the first plane side as it goes toward one side in the first direction, a sixth surface part arranged symmetrically with respect to the fifth surface part centered on the first plane, a seventh surface part arranged symmetrically with respect to the fifth surface part centered on the second plane, and an eighth surface part arranged symmetrically with respect to the sixth surface part centered on the second plane. It is preferable to have these parts.

[0008] (3) In the rotor of the above (1) or (2), the one or more first slits are a plurality of first slits arranged in the extending direction of the first magnet on one side in the second direction, and it is preferable that the interval between each two adjacent first slits among the one or more first slits becomes narrower as it goes toward one side in the first direction.

[0009] (4) In the rotor according to the above (1) or (2), in the rotor core, of both ends in the extending direction of the first magnet on one side in the second direction, the end closer to the first plane and being the end on one side in the extending direction is a first end, and a first air gap is formed from the first end toward one side in the extending direction and the tip of which is parallel to the first plane, and of both ends, a second end which is the end on the opposite side to the first end, after being formed toward the other side in the extending direction, is formed toward the other side in the first direction and the tip of which is parallel to the second plane, a second air gap, a third air gap arranged symmetrically with the first air gap with respect to the first plane, a fourth air gap arranged symmetrically with the second air gap with respect to the first plane, a fifth air gap arranged symmetrically with the first air gap with respect to the second plane, a sixth air gap arranged symmetrically with the second air gap with respect to the second plane, a seventh air gap arranged symmetrically with the third air gap with respect to the second plane, and an eighth air gap arranged symmetrically with the fourth air gap with respect to the second plane. It is preferable to have them.

[0010] (5) The generator of the present invention includes the rotor according to the above (1) or (2), a stator core arranged radially outward with respect to the rotor about the central axis and extending in the circumferential direction about the central axis, and a stator having a coil wound around the stator core and an induced current flowing when the rotor rotates about the central axis.

Effect of the Invention

[0011] According to the present invention, it is possible to provide a rotor that can be made smaller while suppressing reduction of magnetic flux, and a generator including the rotor.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0013] Hereinafter, the rotor etc. according to the embodiment of the present invention will be described with reference to the drawings.

[0014] First, the generator 10 will be described with reference to FIG. 1.

[0015] As shown in FIG. 1, the generator 10 includes a rotating shaft 20, a rotor 30, and a stator 40. Hereinafter, the direction in which the central axis A of the rotor core 50 of the rotor 30 extends is defined as the axial direction (the X-axis direction in FIG. 1), the direction in which the first straight line B orthogonal to the central axis A extends is defined as the first direction (the Y-axis direction in FIG. 1), and the direction in which the second straight line C orthogonal to the central axis A and the first straight line B extends is defined as the second direction (the Z-axis direction in FIG. 1). Further, a virtual plane including the central axis A and including the first straight line B is defined as the first plane (a plane parallel to the XY plane in FIG. 1), and a virtual plane including the central axis A and including the second straight line C is defined as the second plane (a plane parallel to the XZ plane in FIG. 1).

[0016] The rotating shaft 20 extends in the axial direction and is fixed to the inner peripheral surface 51 of the rotor core 50. For example, the rotating shaft 20 is connected to an engine (not shown) or the like and rotates by the engine or the like. For example, the rotating shaft 20 may be formed of a magnetic material or a non-magnetic material.

[0017] The rotor 30 includes a rotor core 50, a pair of first magnets 60a and 60b, and a pair of second magnets 60c and 60d. Each of FIGS. 5 to 10 shows the rotor 30 viewed from six directions, and FIG. 11 is a perspective view of the rotor 30.

[0018] The pair of first magnets 60a and 60b are accommodated in the rotor core 50. The first magnet 60a is accommodated in the first accommodation hole 52a of the rotor core 50, and the first magnet 60b is accommodated in the second accommodation hole 52b of the rotor core 50.

[0019] The pair of first magnets 60a and 60b are arranged symmetrically with respect to the first plane and are located on one side (the positive side in the Y-axis direction in FIG. 1) of the central axis A in the first direction. In the present embodiment, the shortest distance between the first magnet 60a and the second plane in the first direction is shorter than the dimension of the first magnet 60a in the extending direction (the U-axis direction in FIG. 1) of the first magnet 60a, and is shorter than the dimension of the first magnet 60a in the orthogonal direction (the V-axis direction in FIG. 1) that is orthogonal to the central axis A and the extending direction. Similarly, the shortest distance between the first magnet 60b and the second plane in the first direction is shorter than the dimension of the first magnet 60b in the extending direction of the first magnet 60b, and is shorter than the dimension of the first magnet 60b in the orthogonal direction that is orthogonal to the central axis A and the extending direction. The "extending direction of the first magnet 60a" is the direction in which the first magnet 60a extends when viewed from the axial direction. Also, the "extending direction of the first magnet 60b" is the direction in which the first magnet 60b extends when viewed from the axial direction.

[0020] The pair of first magnets 60a and 60b extend such that each first magnet is positioned closer to the first plane as it faces one side in the first direction. The first magnet 60a extends linearly such that it is positioned on the other side in the second direction (the negative side in the Z-axis direction in FIG. 1) as it faces one side in the first direction. The first magnet 60b extends linearly such that it is positioned on one side in the second direction (the positive side in the Z-axis direction in FIG. 1) as it faces one side in the first direction. In the present embodiment, the extending direction of the first magnet 60a is inclined at 45 degrees with respect to the first straight line B and at 45 degrees with respect to the second straight line C. Similarly, the extending direction of the first magnet 60b is inclined at 45 degrees with respect to the first straight line B and at 45 degrees with respect to the second straight line C. Also, the shortest distance between the first magnet 60a and the first plane in the second direction is shorter than the dimension of the first magnet 60a in the extending direction of the first magnet 60a, shorter than the dimension of the first magnet 60a in the central axis A and the orthogonal direction orthogonal to the extending direction, and shorter than the shortest distance between the first magnet 60a and the second plane in the first direction. Similarly, the shortest distance between the first magnet 60b and the first plane in the second direction is shorter than the dimension of the first magnet 60b in the extending direction of the first magnet 60b, shorter than the dimension of the first magnet 60b in the central axis A and the orthogonal direction orthogonal to the extending direction, and shorter than the shortest distance between the first magnet 60b and the second plane in the first direction.

[0021] The pair of first magnets 60a and 60b are magnetized in the central axis A and the orthogonal direction orthogonal to the extending direction of each first magnet. The N pole of the first magnet 60a is positioned symmetrically with respect to the N pole of the first magnet 60b with the first plane as the center. The S pole of the first magnet 60a is positioned symmetrically with respect to the S pole of the first magnet 60b with the first plane as the center. In FIG. 1, the N poles of the first magnet 60a and the first magnet 60b are cross-hatched, and the S poles of the first magnet 60a and the first magnet 60b are not hatched.

[0022] The pair of second magnets 60c and 60d are housed in the rotor core 50. The second magnet 60c is housed in the third housing hole 52c of the rotor core 50, and the second magnet 60d is housed in the fourth housing hole 52d of the rotor core 50.

[0023] A pair of second magnets 60c and 60d are arranged at positions that are plane-symmetrical with respect to a pair of first magnets 60a and 60b about a second plane. The second magnet 60c is arranged at a position that is plane-symmetrical with respect to the first magnet 60a about the second plane. The second magnet 60d is arranged at a position that is plane-symmetrical with respect to the first magnet 60b about the second plane.

[0024] For a pair of second magnets 60c and 60d, the N pole of each second magnet is located at a position that is plane-symmetrical with respect to the S pole of the first magnet about the second plane, and the S pole of each second magnet is located at a position that is plane-symmetrical with respect to the N pole of the first magnet about the second plane. The N pole of the second magnet 60c is located at a position that is plane-symmetrical with respect to the S pole of the first magnet 60a about the second plane. The N pole of the second magnet 60d is located at a position that is plane-symmetrical with respect to the S pole of the first magnet 60b about the second plane. The S pole of the second magnet 60c is located at a position that is plane-symmetrical with respect to the N pole of the first magnet 60a about the second plane. The S pole of the second magnet 60d is located at a position that is plane-symmetrical with respect to the N pole of the first magnet 60b about the second plane. In FIG. 1, cross-hatching is applied to the N poles of the second magnet 60c and the second magnet 60d, and no hatching is applied to the S poles of the second magnet 60c and the second magnet 60d.

[0025] The rotor core 50 has an inner peripheral surface 51, a first accommodation hole 52a, a second accommodation hole 52b, a third accommodation hole 52c, a fourth accommodation hole 52d, a first gap 53a, a second gap 54a, a third gap 53b, a fourth gap 54b, a fifth gap 53c, a sixth gap 54c, a seventh gap 53d, an eighth gap 54d, a plurality of first slits 55a, 56a, 57a, a plurality of second slits 55b, 56b, 57b, a plurality of third slits 55c, 56c, 57c, a plurality of fourth slits 55d, 56d, 57d, and an outer peripheral surface. For example, the rotor core 50 is formed by laminating a plurality of electromagnetic steel sheets.

[0026] The inner peripheral surface 51 is a radial inner peripheral surface centered on the central axis A. As described above, the rotating shaft 20 is fixed to the inner peripheral surface 51. When the rotating shaft 20 rotates about the central axis A, the rotor 30 rotates integrally with the rotating shaft 20 about the central axis A.

[0027] The first accommodation hole 52a penetrates the rotor core 50 in the axial direction and accommodates the first magnet 60a as described above. The second accommodation hole 52b is arranged symmetrically with the first accommodation hole 52a with respect to the first plane and accommodates the first magnet 60b as described above. The third accommodation hole 52c is arranged symmetrically with the first accommodation hole 52a with respect to the second plane and accommodates the second magnet 60c as described above. The fourth accommodation hole 52d is arranged symmetrically with the second accommodation hole 52b with respect to the second plane and accommodates the second magnet 60d as described above.

[0028] The first gap 53a communicates with the first accommodation hole 52a and penetrates the rotor core 50 in the axial direction. The first gap 53a is formed from the end closer to the first plane among the two end portions in the extending direction of the first magnet 60a on one side in the second direction of the pair of first magnets 60a, 60b, which is the end on one side in the extending direction (the plus side in the U-axis direction in FIG. 1), toward one side in the extending direction. The tip end portion (the end portion on one side in the extending direction) of the first gap 53a is parallel to the first plane.

[0029] The second gap 54a communicates with the first accommodation hole 52a and penetrates the rotor core 50 in the axial direction. The second gap 54a is formed from the second end portion on the side opposite to the first end portion among the two end portions in the extending direction of the first magnet 60a toward the other side in the second direction (the minus side in the U-axis direction in FIG. 1), and then toward the other side in the first direction (the minus side in the Y-axis direction in FIG. 1). The tip end portion (the end portion on the other side in the first direction) of the second gap 54a is parallel to the second plane.

[0030] The third gap 53b communicates with the second accommodation hole 52b and penetrates the rotor core 50 in the axial direction. The third gap 53b is arranged symmetrically with respect to the first gap 53a about the first plane.

[0031] The fourth gap 54b communicates with the second accommodation hole 52b and penetrates the rotor core 50 in the axial direction. The fourth gap 54b is arranged symmetrically with respect to the second gap 54a about the first plane.

[0032] The fifth gap 53c communicates with the third accommodation hole 52c and penetrates the rotor core 50 in the axial direction. The fifth gap 53c is arranged symmetrically with respect to the first gap 53a about the second plane.

[0033] The sixth gap 54c communicates with the third accommodation hole 52c and penetrates the rotor core 50 in the axial direction. The sixth gap 54c is arranged symmetrically with respect to the second gap 54a about the second plane.

[0034] The seventh gap 53d communicates with the fourth accommodation hole 52d and penetrates the rotor core 50 in the axial direction. The seventh gap 53d is arranged symmetrically with respect to the third gap 53b about the second plane.

[0035] The eighth gap 54d communicates with the fourth accommodation hole 52d and penetrates the rotor core 50 in the axial direction. The eighth gap 54d is arranged symmetrically with respect to the fourth gap 54b about the second plane.

[0036] Each of the plurality of first slits 55a, 56a, 57a is located on one side in the first direction with respect to the first magnet 60a and extends so as to be located closer to the first plane side as it goes toward one side in the first direction. Each of the plurality of first slits 55a, 56a, 57a extends linearly so as to be located on the other side in the second direction as it goes toward one side in the first direction. Each of the plurality of first slits 55a, 56a, 57a penetrates the rotor core 50 in the axial direction.

[0037] The plurality of first slits 55a, 56a, 57a are arranged side by side in the extending direction of the first magnet 60a. The end of the first slit 55a on the first magnet 60a side, the end of the first slit 56a on the first magnet 60a side, and the end of the first slit 57a on the first magnet 60a side are along the end on one side (the plus side in the V-axis direction in FIG. 1) of the first magnet 60a in the orthogonal direction orthogonal to the central axis A and the extending direction of the first magnet 60a, and are arranged side by side in the extending direction of the first magnet 60a. The end of the first slit 55a on the side opposite to the first magnet 60a side, the end of the first slit 56a on the side opposite to the first magnet 60a side, and the end of the first slit 57a on the side opposite to the first magnet 60a side are arranged side by side in the circumferential direction centered on the central axis A along the first surface portion 58a.

[0038] The interval between each adjacent two of the plurality of first slits 55a, 56a, 57a becomes narrower as it goes toward one side in the first direction. In the present embodiment, the interval between the two first slits 55a, 56a becomes narrower as it goes toward one side in the first direction, and the interval between the two first slits 56a, 57a becomes narrower as it goes toward one side in the first direction. The inclination of the extending direction of the first slit 56a with respect to the first straight line B is larger than the inclination of the extending direction of the first slit 55a with respect to the first straight line B. Also, the inclination of the extending direction of the first slit 57a with respect to the first straight line B is larger than the inclination of the extending direction of the first slit 56a with respect to the first straight line B.

[0039] The plurality of second slits 55b, 56b, 57b are arranged symmetrically with respect to the plurality of first slits 55a, 56a, 57a about the first plane.

[0040] The plurality of third slits 55c, 56c, 57c are arranged symmetrically with respect to the plurality of first slits 55a, 56a, 57a about the second plane.

[0041] The plurality of fourth slits 55d, 56d, 57d are arranged symmetrically with respect to the plurality of second slits 55b, 56b, 57b about the second plane.

[0042] The outer peripheral surface of the rotor core 50 is a radial outer peripheral surface centered on the central axis A. The outer peripheral surface has a first surface portion 58a, a second surface portion 58b, a third surface portion 58c, a fourth surface portion 58d, a fifth surface portion, a sixth surface portion, a seventh surface portion, and an eighth surface portion. The rotor core 50 has a dimension in the second direction that is smaller than the dimension in the first direction. In the present embodiment, the dimension of the rotor core 50 in the second direction is the dimension from the third surface portion 58c to the fourth surface portion 58d in the second direction. Further, the dimension of the rotor core 50 in the first direction is the dimension from one end of the first surface portion 58a on one side in the first direction to the other end of the second surface portion 58b on the other side in the first direction.

[0043] The first surface portion 58a is located on one side in the first direction with respect to the plurality of first slits 55a, 56a, 57a and the plurality of second slits 55b, 56b, 57b, is curved along the circumferential direction centered on the central axis A, and is symmetric with respect to the first plane.

[0044] The second surface portion 58b is arranged symmetrically with respect to the first surface portion 58a with the second plane as the center.

[0045] The third surface portion 58c is located on one side in the second direction with respect to the first magnet 60a on one side in the second direction among the pair of first magnets 60a, 60b and the second magnet 60c on one side in the second direction among the pair of second magnets 60c, 60d, is parallel to the first plane, and is symmetric with respect to the second plane. In the present embodiment, the third surface portion 58c is arranged on the other side of the first slit 57a and on one side of the third slit 57c in the first direction.

[0046] The fourth surface portion 58d is arranged symmetrically with respect to the third surface portion 58c with the first plane as the center.

[0047] The fifth face portion is connected to one end portion on one side in the second direction of the first face portion 58a and one end portion on one side in the first direction of the third face portion 58c, and is arranged to be located on the first plane side as it goes toward one side in the first direction. The fifth face portion has a flat portion 58e and a flat portion 58f. The flat portion 58e is connected to one end portion on one side in the first direction of the third face portion 58c, and is inclined so as to be located on the first plane side as it goes from the end portion toward one side in the first direction. In the present embodiment, the inclination of the flat portion 58e with respect to the first straight line B is smaller than the inclination of the extending direction of the first slit 57a with respect to the first straight line B. The flat portion 58e is arranged up to the other side in the first direction rather than the end portion on the side opposite to the first magnet 60a side of the first slit 57a. The flat portion 58f is connected to one end portion on one side in the first direction of the flat portion 58e, is inclined so as to be located on the first plane side as it goes from the end portion toward one side in the first direction, and is connected to one end portion on one side in the second direction of the first face portion 58a. In the present embodiment, the inclination of the flat portion 58f with respect to the first straight line B is larger than the inclination of the extending direction of the first slit 57a with respect to the first straight line B. The end portion on one side in the first direction of the flat portion 58f is located on one side in the second direction with respect to the end portion on the side opposite to the first magnet 60a side of the first slit 57a.

[0048] The sixth face portion is arranged symmetrically with the fifth face portion about the first plane. The sixth face portion has a flat portion 58g arranged symmetrically with the flat portion 58e about the first plane and a flat portion 58h arranged symmetrically with the flat portion 58f about the first plane.

[0049] The seventh face portion is arranged symmetrically with the fifth face portion about the second plane. The seventh face portion has a flat portion 58i arranged symmetrically with the flat portion 58e about the second plane and a flat portion 58j arranged symmetrically with the flat portion 58f about the second plane.

[0050] The eighth face portion is arranged symmetrically with respect to the sixth face portion about the second plane. The eighth face portion has a flat portion 58k arranged symmetrically with respect to the flat portion 58g about the second plane, and a flat portion 58l arranged symmetrically with respect to the flat portion 58h about the second plane.

[0051] The stator 40 has a stator core 70 and a plurality of coils 80.

[0052] The stator core 70 is arranged radially outward about the central axis A with respect to the rotor 30. The stator core 70 extends in the circumferential direction about the central axis A. The stator core 70 has a yoke 71, a plurality of teeth 72, and a plurality of through holes 73a and 73b. For example, the stator core 70 is formed by laminating a plurality of electromagnetic steel sheets.

[0053] The yoke 71 extends in the circumferential direction about the central axis A. Each tooth 72 projects radially inward from the yoke 71 about the central axis A. The plurality of teeth 72 are arranged at equal intervals in the circumferential direction about the central axis A. The plurality of teeth 72 have the same shape and the same dimensions as each other. The inner circumferential surface of each tooth 72 in the radial direction about the central axis A is curved along the circumferential direction about the central axis A and faces the outer circumferential surface of the rotor core 50 in the radial direction about the central axis A. Between each two adjacent teeth 72 among the plurality of teeth 72, a slot in which the coil 80 is arranged is formed. Between the tip portions of each two adjacent teeth 72 among the plurality of teeth 72, a slot opening communicating with the slot is formed. The through hole 73a and the through hole 73b penetrate the stator core 70 in the axial direction and are arranged at 180-degree intervals in the circumferential direction about the central axis A.

[0054] Each coil 80 is wound around the stator core 70, and an induced current flows when the rotor 30 rotates about the central axis A. In the present embodiment, each coil 80 is wound around a winding axis extending in a direction orthogonal to the central axis A. In the state shown in FIG. 1, the winding axis extends in the first direction, and each coil 80 is wound around the winding axis so as to pass through two slots that are arranged symmetrically with respect to the first plane among a plurality of slots. The number of turns of each coil 80 does not have to be the same, and is appropriately determined, for example, to make the voltage waveform approach a sine wave.

[0055] The generator 10 as described above is, for example, a single-phase AC generator in which the rotational speed of the rotor 30 with respect to the stator 40 is driven at a constant speed. When the rotor 30 rotates from the rotational position shown in FIG. 1 to a rotational position 90 degrees counterclockwise with respect to the rotational position, the magnetic flux linking with the plurality of coils 80 tends to decrease, so the induced current flowing in one direction in the coil 80 tends to decrease. When the rotor 30 rotates from a rotational position 90 degrees counterclockwise with respect to the rotational position shown in FIG. 1 to a rotational position 180 degrees counterclockwise with respect to the rotational position shown in FIG. 1, the magnetic flux linking with the plurality of coils 80 tends to increase, so the induced current flowing in the other direction in the coil 80 tends to increase. When the rotor 30 rotates from a rotational position 180 degrees counterclockwise with respect to the rotational position shown in FIG. 1 to a rotational position 270 degrees counterclockwise with respect to the rotational position shown in FIG. 1, the magnetic flux linking with the plurality of coils 80 tends to decrease, so the induced current flowing in the other direction in the coil 80 tends to decrease. When the rotor 30 rotates from a rotational position 270 degrees counterclockwise with respect to the rotational position shown in FIG. 1 to a rotational position 360 degrees counterclockwise with respect to the rotational position shown in FIG. 1, the magnetic flux linking with the plurality of coils 80 tends to increase, so the induced current flowing in one direction in the coil 80 tends to increase. Thus, by rotating the rotor 30 with respect to the stator 40 at a constant rotational speed, a substantially alternating current can be generated.

[0056] The generator 10 can be configured without using semiconductors and brushes, and can be driven without using an inverter. As a result, it becomes unnecessary to use weak current, defects due to brush sticking can be avoided, and defects of capacitors can be avoided. Therefore, even when the generator 10 is left unattended for a long time, deterioration of the generator 10 can be suppressed. Accordingly, it becomes easier to ensure the long-term reliability of the generator 10, so that the generator 10 can be operated more reliably when used in an emergency or the like.

[0057] Next, with reference to FIGS. 2 to 4, a comparison result between the rotor 130 and the like according to the comparative example and the rotor and the like according to the embodiment will be described.

[0058] As shown in FIG. 2, in the rotor 130 according to the comparative example, a pair of magnets 160a and 160b extend so as to be located on the side opposite to the first plane side as they go toward one side in the first direction, and a pair of magnets 160c and 160d extend so as to be located on the side opposite to the first plane side as they go toward the other side in the first direction. In this respect, it is different from the rotor 30. Further, in the rotor 130 according to the comparative example, both end portions in the second direction of the rotor 130 are curved so as to be recessed inward. In this respect, it is different from the rotor 30. Since the stator 140 according to the comparative example is the same as the stator 40, a detailed description thereof will be omitted here.

[0059] The rotor according to the embodiment is the same as the rotor 30, and the stator according to the embodiment is the same as the stator 40. Therefore, a detailed description thereof will be omitted here.

[0060] As shown in FIG. 3, in the comparative example, the direction of the magnetic flux instantaneously reverses greatly around 155 degrees, and the direction of the magnetic flux instantaneously reverses greatly around 205 degrees. Further, the direction of the magnetic flux instantaneously reverses greatly around 335 degrees, and the direction of the magnetic flux instantaneously reverses greatly around 25 degrees.

[0061] On the other hand, as shown in FIG. 4, in the embodiment, it was found that there is no tendency for the direction of the magnetic flux to suddenly reverse in this way, and the direction of the magnetic flux can be reversed smoothly compared to the comparative example.

[0062] As described above, the rotor 30 in the embodiment of the present invention includes a rotor core 50, a pair of first magnets 60a and 60b accommodated in the rotor core 50, and a pair of second magnets 60c and 60d accommodated in the rotor core 50. The pair of first magnets 60a and 60b are arranged symmetrically with respect to a first plane including a central axis A of the rotor core 50 and including a first straight line B orthogonal to the central axis A. The first straight line B is located on one side of the central axis A in a first direction in which the first straight line B extends, and each first magnet extends so as to be located closer to the first plane as it faces one side in the first direction. Each first magnet is magnetized in a direction orthogonal to the central axis A and the extending direction of the first magnet. The pair of second magnets 60c and 60d are arranged at positions symmetric with the pair of first magnets 60a and 60b with respect to a second plane including the central axis A and including a second straight line C orthogonal to the central axis A and the first straight line B. The N pole of each second magnet is located at a position symmetric with the S pole of the first magnet with respect to the second plane, and the S pole of each second magnet is located at a position symmetric with the N pole of the first magnet with respect to the second plane. The rotor core 50 has one or more first slits 55a, 56a, 57a that extend so as to be located on one side in the first direction with respect to the first magnet 60a on one side in the second direction in which the second straight line C extends among the pair of first magnets 60a and 60b and to be located closer to the first plane as it faces one side in the first direction, one or more second slits 55b, 56b, 57b arranged symmetrically with the one or more first slits 55a, 56a, 57a with respect to the first plane, one or more third slits 55c, 56c, 57c arranged symmetrically with the one or more first slits 55a, 56a, 57a with respect to the second plane, and one or more fourth slits 55d, 56d, 57d arranged symmetrically with the one or more second slits 55b, 56b, 57b with respect to the second plane, and the dimension in the second direction is smaller than the dimension in the first direction.

[0063] According to this, while suppressing the increase in the size of the rotor 30, a larger pair of first magnets 60a and 60b can be arranged, and a larger pair of second magnets 60c and 60d can be arranged. Therefore, the rotor 20 can be made smaller while suppressing the reduction of magnetic flux. Also, it becomes easier to collect magnetic flux toward one edge portion of the rotor 30 in the first direction, and it becomes easier to collect magnetic flux toward the other edge portion of the rotor 30 in the first direction. Thus, the reduction of magnetic flux can be further suppressed.

[0064] Also, in the rotor 30 in the embodiment of the present invention, the outer peripheral surface of the rotor core 50 is located on one side in the first direction with respect to one or more first slits 55a, 56a, 57a and one or more second slits 55b, 56b, 57b, is curved along the circumferential direction centered on the central axis A, and is plane-symmetric about the first plane, a first surface portion 58a; a second surface portion 58b arranged symmetrically with the first surface portion 58a about the second plane; a third surface portion 58c located on one side in the second direction with respect to the second magnet 60c on one side in the second direction among the first magnet 60a on one side in the second direction and the pair of second magnets 60c and 60d, parallel to the first plane, and plane-symmetric about the second plane; a fourth surface portion 58d arranged symmetrically with the third surface portion 58c about the first plane; a fifth surface portion (plane portions 58e and 58f) connected to the end portion on one side in the second direction of the first surface portion 58a and the end portion on one side in the first direction of the third surface portion 58c and located on the first plane side as it goes toward one side in the first direction; a sixth surface portion (plane portions 58g and 58h) arranged symmetrically with the fifth surface portion about the first plane; a seventh surface portion (plane portions 58i and 58j) arranged symmetrically with the fifth surface portion about the second plane; and an eighth surface portion (plane portions 58k and 58l) arranged symmetrically with the sixth surface portion about the second plane.

[0065] According to this, it becomes even easier to collect magnetic flux toward one edge portion of the rotor 30 in the first direction, and it becomes even easier to collect magnetic flux toward the other edge portion of the rotor 30 in the first direction. Therefore, the rotor 20 can be made smaller while further suppressing the reduction of magnetic flux.

[0066] Further, in the rotor 30 according to the embodiment of the present invention, one or more first slits 55a, 56a, 57a are a plurality of first slits 55a, 56a, 57a arranged in the extending direction of the first magnet 60a on one side in the second direction, and the interval between each two adjacent first slits among the one or more first slits 55a, 56a, 57a becomes narrower as it goes toward one side in the first direction.

[0067] According to this, it becomes easier to further collect magnetic flux toward the edge on one side in the first direction of the rotor 30, and it also becomes easier to further collect magnetic flux toward the edge on the other side in the first direction of the rotor 30. Therefore, the rotor 20 can be made smaller while further suppressing the reduction of magnetic flux.

[0068] Further, in the rotor 30 according to the embodiment of the present invention, the rotor core 50 is the end portion closer to the first plane among both end portions in the extending direction of the first magnet 60a on one side in the second direction and is the first end portion which is the end portion on one side in the extending direction, and a first gap 53a formed toward one side in the extending direction from the first end portion and having a tip portion parallel to the first plane, a second gap 54a formed toward the other side in the extending direction from the second end portion which is the end portion on the side opposite to the first end portion among both end portions and then toward the other side in the first direction and having a tip portion parallel to the second plane, a third gap 53b arranged symmetrically with the first gap 53a with respect to the first plane, a fourth gap 54b arranged symmetrically with the second gap 54a with respect to the first plane, a fifth gap 53c arranged symmetrically with the first gap 53a with respect to the second plane, a sixth gap 54c arranged symmetrically with the second gap 54a with respect to the second plane, a seventh gap 53d arranged symmetrically with the third gap 53b with respect to the second plane, and an eighth gap 54d arranged symmetrically with the fourth gap 54b with respect to the second plane.

[0069] According to this, it becomes easier to further collect magnetic flux toward the edge on one side in the first direction of the rotor 30, and it also becomes easier to further collect magnetic flux toward the edge on the other side in the first direction of the rotor 30. Therefore, the rotor 20 can be made smaller while further suppressing the reduction of magnetic flux.

[0070] Further, the generator 10 in the embodiment of the present invention includes the above-described rotor 30, a stator core 70 that is disposed radially outward with respect to the rotor 30 about the central axis A and extends in the circumferential direction about the central axis A, and a stator 40 that has a coil 80 wound around the stator core 70 and through which an induced current flows when the rotor 30 rotates about the central axis A.

[0071] According to this, the same operational effects as those of the above-described rotor 30 are achieved.

[0072] As described above, the embodiments of the present invention have been described. However, these are merely examples, and do not particularly limit the present invention. Specifically, configurations and the like can be appropriately changed in design. Further, the operations and effects described in the embodiments of the invention merely list the most suitable operations and effects resulting from the present invention, and the operations and effects according to the present invention are not limited to those described in the embodiments of the present invention.

[0073] In the above embodiment, the case where a plurality of first slits 55a, 56a, 57a are arranged has been described, but the present invention is not limited to this. For example, one first slit may be arranged instead of a plurality, two first slits may be arranged, or four or more first slits may be arranged. The same applies to the second slit, the third slit, and the fourth slit.

[0074] Further, in the above embodiment, the case where the interval between each two adjacent first slits among the plurality of first slits 55a, 56a, 57a becomes narrower as it goes toward one side in the first direction has been described, but the present invention is not limited to this. For example, the interval between each two adjacent first slits among the plurality of first slits may be constant as it goes toward one side in the first direction. That is, the plurality of first slits may be parallel to each other. The same applies to the second slit, the third slit, and the fourth slit.

[0075] In addition, in the above embodiment, the case where the outer peripheral surface of the rotor core 50 has the third surface portion 58c, the fifth surface portion, and the seventh surface portion has been described, but the present invention is not limited to this. For example, the outer peripheral surface of the rotor core may be connected to one end on one side in the second direction of the first surface portion and one end on one side in the second direction of the second surface portion, and may have a curved portion or the like that is convexly curved toward one side in the second direction when viewed from the axial direction and is plane-symmetric about the second plane. The same applies to the fourth surface portion 58d, the sixth surface portion, and the eighth surface portion.

Explanation of Signs

[0076] 10 Generator 20 Rotating shaft 30 Rotor 40 Stator 50 Rotor core 51 Inner peripheral surface 52a First accommodation hole 52b Second accommodation hole 52c Third accommodation hole 52d Fourth accommodation hole 53a First gap 54a Second gap 53b Third gap 54b Fourth gap 53c Fifth gap 54c Sixth gap 53d Seventh gap 54d Eighth gap 55a, 56a, 57a First slit 55b, 56b, 57b Second slit 55c, 56c, 57c Third slit 55d, 56d, 57d Fourth slit 58a First surface portion 58b Second surface portion 58c Third surface portion 58d Fourth surface portion 58e, 58f, 58g, 58h, 58i, 58j, 58k, 58l Plane portion 60a, 60b First magnet 60c, 60d Second magnet 70 Stator core 71 Yoke 72 teeth 73a, 73b through holes 80 coil Axis A Straight line B Straight line C

Claims

1. A rotor core, a pair of first magnets accommodated in the rotor core, and a pair of second magnets accommodated in the rotor core, wherein the pair of first magnets are arranged symmetrically with respect to a first plane including a central axis of the rotor core and including a first straight line orthogonal to the central axis, are located on one side of the central axis in a first direction in which the first straight line extends, and extend such that each of the first magnets is located closer to the first plane as it faces one side in the first direction, and each of the first magnets is magnetized in a direction orthogonal to the central axis and the extending direction of the first magnet, the pair of second magnets are arranged symmetrically with the pair of first magnets with respect to a second plane including the central axis and including a second straight line orthogonal to the central axis and the first straight line, the N pole of each of the second magnets is located symmetrically with the S pole of the first magnet with respect to the second plane, and the S pole of each of the second magnets is located symmetrically with the N pole of the first magnet with respect to the second plane, the rotor core has one or more first slits that extend such that they are located on one side in the first direction with respect to the first magnet on one side in a second direction in which the second straight line extends among the pair of first magnets and are located closer to the first plane as they face one side in the first direction, one or more second slits that are arranged symmetrically with the one or more first slits with respect to the first plane, one or more third slits that are arranged symmetrically with the one or more first slits with respect to the second plane, and one or more fourth slits that are arranged symmetrically with the one or more second slits with respect to the second plane, and the dimension in the second direction is smaller than the dimension in the first direction. A rotor characterized by this.

2. The outer peripheral surface of the rotor core has a first surface portion that is located on one side in the first direction with respect to the one or more first slits and the one or more second slits, is curved along the circumferential direction centered on the central axis, and is symmetric with respect to the first plane; a second surface portion that is arranged symmetrically with respect to the first surface portion centered on the second plane; a third surface portion that is located on one side in the second direction with respect to the second magnet on one side in the second direction among the first magnet and the pair of second magnets on one side in the second direction, is parallel to the first plane, and is symmetric with respect to the second plane; a fourth surface portion that is arranged symmetrically with respect to the third surface portion centered on the first plane; a fifth surface portion that is connected to the end portion on one side in the second direction of the first surface portion and the end portion on one side in the first direction of the third surface portion and is located on the first plane side as it goes toward one side in the first direction; a sixth surface portion that is arranged symmetrically with respect to the fifth surface portion centered on the first plane; a seventh surface portion that is arranged symmetrically with respect to the fifth surface portion centered on the second plane; and an eighth surface portion that is arranged symmetrically with respect to the sixth surface portion centered on the second plane. The rotor according to claim 1, characterized by having the above.

3. The one or more first slits are a plurality of first slits arranged in the extending direction of the first magnet on one side in the second direction, The interval between each two adjacent first slits among the one or more first slits becomes narrower as it goes toward one side in the first direction. The rotor according to claim 1 or 2, characterized by the above.

4. The rotor core includes a first gap formed from a first end portion, which is an end portion closer to the first plane among both end portions in the extending direction of the first magnet on one side in the second direction and is an end portion on one side in the extending direction, toward one side in the extending direction and having a tip parallel to the first plane; a second gap formed from a second end portion, which is an end portion opposite to the first end portion among both end portions, toward the other side in the extending direction and then toward the other side in the first direction and having a tip parallel to the second plane; a third gap arranged symmetrically with the first gap with respect to the first plane; a fourth gap arranged symmetrically with the second gap with respect to the first plane; a fifth gap arranged symmetrically with the first gap with respect to the second plane; a sixth gap arranged symmetrically with the second gap with respect to the second plane; a seventh gap arranged symmetrically with the third gap with respect to the second plane; and an eighth gap arranged symmetrically with the fourth gap with respect to the second plane. The rotor according to claim 1 or 2 is characterized by having these gaps.

5. A rotor according to claim 1 or 2, a stator core arranged radially outward with respect to the rotor about the central axis and extending in the circumferential direction about the central axis, and a stator having a coil wound around the stator core and through which an induced current flows when the rotor rotates about the central axis. The generator is characterized by comprising these components.

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