JP4960749B2 - Axial gap type motor - Google Patents

Description

  The present invention relates to an axial gap type motor.

2. Description of the Related Art Conventionally, for example, a pair of stators arranged opposite to each other so as to sandwich a rotor from both sides in the rotation axis direction is provided, and a magnetic flux loop via a pair of stators is formed for a field magnetic flux generated by a permanent magnet of the rotor. A shaft gap type permanent magnet synchronous machine is known (see, for example, Patent Document 1 and Patent Document 2).
JP-A-10-271784 JP 2001-136721 A

  By the way, in the permanent magnet synchronous machine according to the above prior art, for example, when the energization amount of the current energized to each stator winding of a pair of stators is relatively small, etc., the magnetic flux (fixed) The amount of magnetic flux (linkage magnetic flux) that links the rotor in the magnetic flux) may decrease, and the leakage magnetic flux may increase, and the operation efficiency of the permanent magnet synchronous machine cannot be improved. Arise.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an axial gap type motor capable of improving driving efficiency.

  In order to solve the above problems and achieve the object, an axial gap type motor according to a first aspect of the present invention includes a rotor that can rotate around a rotation axis (for example, the rotor 11 in the embodiment), and An axial gap type motor comprising a stator (for example, the stator 12 in the embodiment) disposed opposite to the rotor from at least one side in a rotation axis direction parallel to the rotation axis of the rotor, wherein the rotor is magnetized A plurality of main permanent magnets (for example, the main permanent magnet piece 41 in the embodiment) arranged in the circumferential direction with the direction being the rotation axis direction, and the magnetization direction being a direction perpendicular to the rotation axis direction, Between the plurality of sub permanent magnets (for example, the sub permanent magnet piece 43 in the embodiment) arranged in the vicinity of the end of the main permanent magnet and the two sub permanent magnets adjacent in the circumferential direction. A magnetic member (for example, magnetic material member 42 in the embodiment) disposed on the surface of at least one side of the permanent magnet in the rotational axis direction, and the magnetic member is a rolled material formed by rolling. The rolling direction in at least the radially inward or radially outward region is the rotational axis direction, and the rolling direction in the region between the radially inward and the radially outward region is the rotor. In the circumferential direction.

  Furthermore, in the axial gap type motor according to the second aspect of the present invention, the rolled material is an electromagnetic steel plate, and the magnetic member is a laminated steel plate in which a plurality of the electromagnetic steel plates are laminated in the radial direction of the rotor.

  Furthermore, in the axial gap type motor according to the third aspect of the present invention, the sub permanent magnet is a pair of first sub permanent magnets (for example, implemented) disposed near both ends in the rotation axis direction of the main permanent magnet. Sub-permanent magnet piece 43) and a second sub-permanent magnet (for example, sub-permanent magnet piece 43 in the embodiment), and the stator is arranged oppositely in the rotation axis direction so as to extend in the rotation axis direction. A pair of first stators (for example, the stator 12 in the embodiment) and a second stator (for example, the stator 12 in the embodiment) that sandwich the rotor from both sides are provided.

  According to the axial gap type motor according to the first aspect of the present invention, the magnetic member disposed on the surface of the main permanent magnet of the rotor is made of a rolled material, so that the initial magnetic permeability is relative in the rolling direction of the rolled material. Become expensive. Therefore, the magnetic path between the rotor and the stator is set by setting the rolling direction of the magnetic member at least in the radially inner region or the radially outer region to the rotation axis direction, that is, the direction from the rotor to the stator. Suppresses leakage of current magnetic flux in the air gap (that is, magnetic flux caused by the current applied to the stator winding of the stator) radially inward or outward without linking the rotor The magnet torque resulting from the attraction / repulsion force generated between the current magnetic field and the main permanent magnet can be increased. In addition, the rolling direction in the region between the radially inner side and the radially outer side of the magnetic member is set to the circumferential direction of the rotor, that is, the rotational direction of the rotor, so that the current magnetic field and the magnetic member are placed between each other. Since the rotational torque (reluctance torque) resulting from the generated attractive force can be increased and the hysteresis loss can be reduced, the occurrence of back torque in the counter-rotating direction can be suppressed, and the cogging torque and torque can be suppressed. Ripple can be reduced. As a result, the operation efficiency of the axial gap type motor can be improved.

  Furthermore, according to the axial gap type motor according to the second aspect of the present invention, the magnet torque and the reluctance torque can be increased, and the operation efficiency of the axial gap type motor can be improved.

  Further, according to the axial gap type motor according to the third aspect of the present invention, the field magnetic flux is generated by the magnetic lens effect by the so-called permanent magnet Halbach arrangement of the main permanent magnet, the first sub permanent magnet, and the second sub permanent magnet. The field magnetic flux can be swept between the first and second stators paired in the direction of the rotation axis while properly converging, and the amount of magnetic flux interlinked with the stator winding of each stator can be increased. .

Hereinafter, an embodiment of an axial gap type motor of the present invention will be described with reference to the accompanying drawings.
An axial gap type motor 10 according to the present embodiment includes, for example, a substantially annular rotor 11 provided to be rotatable around a rotation axis O of the axial gap type motor 10, as shown in FIGS. A pair of stators 12 and 12 having a plurality of stator windings that are arranged opposite to each other so as to sandwich the rotor 11 from both sides in the direction of the axis O and generate a rotating magnetic field that rotates the rotor 11. Yes.

  The axial gap type motor 10 is mounted as a drive source in a vehicle such as a hybrid vehicle or an electric vehicle, for example, and an output shaft is connected to an input shaft of a transmission (not shown), whereby the driving force of the axial gap type motor 10 is obtained. Is transmitted to drive wheels (not shown) of the vehicle via a transmission.

  Further, when the driving force is transmitted from the driving wheel side to the axial gap type motor 10 during deceleration of the vehicle, the axial gap type motor 10 functions as a generator to generate a so-called regenerative braking force, and the kinetic energy of the vehicle body is electrically converted. Recover as energy (regenerative energy). Further, for example, in a hybrid vehicle, when the rotating shaft of the axial gap type motor 10 is connected to the crankshaft of an internal combustion engine (not shown), the axial gap motor 10 is also axially transmitted when the output of the internal combustion engine is transmitted to the axial gap type motor 10. The gap type motor 10 functions as a generator and generates power generation energy.

  Each stator 12 faces the rotor 11 along the direction of the rotation axis O from a substantially annular plate-shaped yoke portion 21 and a position at a predetermined interval in the circumferential direction on the facing surface of the yoke portion 21 facing the rotor 11. A plurality of teeth 22,..., 22 that protrude and extend in the radial direction, and a stator winding (for example, stator winding 12 a shown in FIG. 4) that is mounted between the appropriate teeth 22, 22. Has been.

Each stator 12 is a 6N type having, for example, six main poles (for example, U ⁺ , V ⁺ , W ⁺ , U ⁻ , V ⁻ , W ⁻ ), and each stator 12 has a U ⁺ , The U ⁻ , V ⁻ , and W ⁻ poles of the other stator 12 are set to face the V ⁺ and W ⁺ poles in the direction of the rotation axis O.
For example, with respect to a pair of stators 12 and 12 facing in the direction of the rotation axis O, three stators 12 corresponding to one of U ⁺ , V ⁺ , W ⁺ poles and one of U ⁻ , V ⁻ , W ⁻ poles The teeth 22, 22, 22 and the three teeth 22, 22, 22 of the other stator 12 corresponding to the other of the U ⁺ , V ⁺ , W ⁺ pole and the other of the U ⁻ , V ⁻ , W ⁻ poles rotate. It is set so as to face each other in the direction of the axis O, and is set so that the energized state with respect to the teeth 22 of one stator 12 and the teeth 22 of the other stator 12 facing each other in the direction of the rotation axis O is reversed in electrical angle. ing.

  The circumferential width of the teeth 22 is, for example, from the inside in the radial direction to the outside, and gradually increases from, for example, the inner circumference side width Ta to the outer circumference side width Tb (> Ta), and adjacent teeth 22 in the circumferential direction. , 22 in the circumferential direction, that is, the slot width of the slot 23 formed between the adjacent teeth 22 and 22 in the circumferential direction and extending in the radial direction is set to be a predetermined constant value in the radial direction. ing.

  The rotor 11 includes a plurality of main magnet pole portions 31,..., A plurality of sub magnet portions 32,... 32, and a rotor frame 33 made of a nonmagnetic material. The sub magnet portions 32 are accommodated in the rotor frame 33 in a state of being alternately arranged in the circumferential direction.

The rotor frame 33 includes an inner peripheral side cylindrical portion 35, an outer peripheral side cylindrical portion 36, and an inner peripheral side cylinder connected by a plurality of radial ribs 34,. And a connecting portion 37 that is formed in an annular plate shape protruding inward from the inner peripheral surface of the shaped portion 35 and connected to an external drive shaft (for example, an input shaft of a vehicle transmission). Has been.
In this embodiment, since the inner peripheral cylindrical portion 35 of the rotor frame 33 is connected to an external drive shaft, the radially inner side of the radial rib 34 is the shaft portion side, and the radial rib 34 The radially outer side is the rim portion side.

  The cross-sectional area of the radial rib 34 in the radial direction is set to be a predetermined constant value in the radial direction. The circumferential width of the radial rib 34 is equal to the circumferential width of a sub permanent magnet piece 43 described later. Further, the thickness of the radial rib 34 in the direction of the rotation axis O is set to be a predetermined constant value in the radial direction.

  For example, as shown in FIG. 3, the main magnet pole portion 31 has a substantially sector plate-shaped main permanent magnet piece 41 magnetized in the thickness direction (that is, the rotation axis O direction), and the main permanent magnet piece 41 is thickened. The main permanent magnet pieces 41 and 41 of the main magnet pole portions 31 and 31 adjacent to each other in the circumferential direction are configured to include a pair of substantially fan-shaped magnetic material members 42 and 42 sandwiched from both sides in the vertical direction. For example, as shown in FIG. 4, the magnetization directions are set to be different from each other.

The plurality of main magnet pole portions 31,..., 31 accommodated in the rotor frame 33 are sandwiched by the inner peripheral cylindrical portion 35 and the outer peripheral cylindrical portion 36 from both sides in the radial direction, and also in the radial direction. The ribs 34 are arranged adjacent to each other in the circumferential direction.
In the rotor frame 33, the main permanent magnet piece 41 of each main magnet pole portion 31 is sandwiched from both sides in the circumferential direction by two radial ribs 34, and the thickness of the main permanent magnet piece 41 in the rotation axis O direction is: Similar to the radial rib 34, it is set to have a predetermined constant value in the radial direction.
Further, the thickness of the magnetic material member 42 in the direction of the rotation axis O is set to be a predetermined constant value in the radial direction, similarly to the sub permanent magnet piece 43 described later.

For example, as shown in FIGS. 2 and 3, the sub-magnet portion 32 includes a pair of sub-permanent magnet pieces 43 and 43 that sandwich the radial ribs 34 from both sides in the rotation axis O direction in the rotor frame 33. The pair of sub permanent magnet pieces 43, 43 facing each other in the direction of the rotation axis O are magnetized in a direction (substantially circumferential direction) orthogonal to the direction of the rotation axis O and the radial direction, respectively, for example, as shown in FIG. The magnetization direction is different.
The thickness of the secondary permanent magnet piece 43 in the direction of the rotation axis O is a predetermined constant value in the radial direction, like the magnetic member 42, and the circumferential width of the secondary permanent magnet piece 43 is the radial rib 34. It is equivalent to the circumferential width of.
In the rotor frame 33, the sub permanent magnet pieces 43 and 43 of the sub magnet portions 32 and 32 adjacent in the circumferential direction sandwich the magnetic material member 42 of the main magnet pole portion 31 from both sides in the circumferential direction.
In FIG. 2, which shows the rotor frame 33 of the rotor 11 and the components other than the rotor frame 33 (that is, the main magnet pole portion 31 and the sub magnet portion 32) separated from each other, a pair facing each other in the direction of the rotation axis O. A space portion 34a in which the radial rib 34 of the rotor frame 33 is disposed is formed between the sub permanent magnet pieces 43, 43 and between the main permanent magnet pieces 41, 41 adjacent in the circumferential direction.

As shown in FIG. 4, for example, the pair of sub permanent magnet pieces 43 and 43 facing each other in the circumferential direction via the magnetic material member 42 have different magnetization directions.
The pair of sub permanent magnet pieces 43 and 43 arranged on one side in the direction of the rotation axis O have the same polarity as the magnetic pole on one side of the main permanent magnet piece 41 magnetized in the direction of the rotation axis O. A pair of sub-permanent magnet pieces 43, 43 that are opposed to each other and arranged on the other side in the direction of the rotation axis O are magnetic poles having the same polarity as the magnetic pole on the other side of the main permanent magnet piece 41 magnetized in the direction of the rotation axis O. Are arranged to face each other.

That is, for example, a pair of magnetic material members 42 sandwiched from both sides in the circumferential direction on one side in the rotational axis O direction with respect to the main permanent magnet piece 41 having one side in the rotational axis O direction as the N pole and the other side as the S pole. The sub-permanent magnet pieces 43 and 43 are arranged so that their N poles face each other in the circumferential direction, and a pair of sub-permanent magnets sandwiching the magnetic material member 42 from both sides in the circumferential direction on the other side in the rotation axis O direction. The pieces 43 and 43 are arranged so that the S poles of each other face each other in the circumferential direction.
Accordingly, the magnetic fluxes of the main permanent magnet piece 41 and the sub permanent magnet pieces 43 and 43 are converged by the magnetic lens effect due to the so-called permanent magnet Halbach arrangement, and the effective magnetic flux linked to the stators 12 and 12 is relatively relative to each other. It is going to increase.

In this embodiment, the magnetic material member 42 is configured by laminating a plurality of electromagnetic steel plates formed by rolling in the radial direction of the rotor 11.
Each of the electromagnetic steel plates constituting the magnetic member 42 has at least a radially inward or radially outward region (for example, a radially inward region and a radially outward side) as shown in FIGS. 3 to 5, for example. The rolling direction in the region) is the rotation axis O direction, and the rolling direction in the region between the radially inner side and the radially outer side (for example, the radially central region) is the circumferential direction of the rotor 11. Is set to
That is, for example, as shown in FIG. 3, the magnetic material member 42 includes a circumferential rolling portion 42 a in which the rolling direction is the circumferential direction of the rotor 11, and an axial rolling portion 42 b in which the rolling direction is the rotational axis O direction. The circumferentially rolled portion 42a is sandwiched from both sides in the radial direction by a pair of axially rolled portions 42b and 42b opposed in the radial direction.
In FIG. 5, which shows only components (that is, the main magnet pole portion 31 and the sub magnet portion 32) other than the rotor frame 33 of the rotor 11, a pair of sub permanent magnet pieces 43 facing each other in the direction of the rotation axis O. A space portion 34a in which the radial ribs 34 of the rotor frame 33 are disposed is formed between the main permanent magnet pieces 41 and 41 adjacent to each other in the circumferential direction.

  That is, even if the electrical steel sheet formed by rolling is a non-oriented electrical steel sheet, the magnetic properties change according to the relative direction with respect to the rolling direction, for example, as shown in FIG. Although each DC magnetization curve in a high magnetic flux density region is substantially equivalent to a direction parallel to the rolling direction, a direction inclined by 45 ° with respect to the rolling direction, and a direction orthogonal to the rolling direction, In the relatively low magnetic flux density region, since the deviation between the direct current magnetization curves increases, the initial magnetic permeability is different from each other, and in particular, it is easily magnetized in the rolling direction.

For this reason, the rolling direction in the central region in the radial direction between the radially inner side and the radially outer side is the circumferential direction of the rotor 11, that is, the rotor 11 By setting it to be in the rotational direction, this central region in the radial direction is easily magnetized in the rotational direction of the rotor 11, and for example, as shown in FIG. 4, the stator winding 12 a of the stator 12 is energized. Rotational torque due to the attractive force generated between the reluctance torque generating portion at the circumferential end of the magnetic material member 42 that changes to either the N pole or the S pole by the current magnetic flux caused by the current and the current magnetic field ( That is, the reluctance torque) can be increased and the hysteresis loss can be reduced, so that the occurrence of back torque in the counter-rotating direction can be suppressed, and the cogging torque and It is possible to reduce the Rukurippuru.
For example, in an example of the torque change according to the phase current advance shown in FIG. 7, relative to the circumferential direction of the rotor 11, that is, the rotational direction of the rotor 11 in the radially central region with respect to the magnetic material member 42 made of a rolled material. In the embodiment in which the direction having a high initial permeability is arranged, the reluctance torque is compared with the comparative example in which the direction having a relatively high initial permeability is set in a direction other than the circumferential direction of the rotor 11 in the radially central region. Has increased.

Further, with respect to each electromagnetic steel sheet constituting the magnetic material member 42, the rolling direction is at least in the radially inward or radially outward region (for example, the radially inward region and the radially outward region). By setting it to be in the O direction (that is, the magnetic path gap direction), the magnetic flux is easily focused in this direction. For example, as shown in FIG. 5, the magnetic path gap between the rotor 11 and the stator 12 Generation of leakage magnetic flux at the stator, that is, current magnetic flux generated from the stator 12 can be prevented from leaking radially inward or radially outward without interlinking the rotor 11. The magnet torque resulting from the attraction / repulsion force generated between the current magnetic field by 12a and the field magnetic flux by the main permanent magnet piece 41 and the sub permanent magnet piece 43 can be increased.
For example, in the example of the torque change according to the phase current advance angle shown in FIG. 7, relative to the magnetic material member 42 made of a rolled material in the radially inner region and the radially outer region relatively in the direction of the rotation axis O. In the example in which the direction having a high magnetic permeability is arranged, the direction having a relatively high initial permeability in the radially inner region and the radially outer region is set to a direction other than the rotation axis O direction. Thus, the magnet torque is increasing.

As described above, according to the axial gap type motor 10 according to the present embodiment, the rotor in the radially central region between the radially inner side and the radially outer side with respect to the magnetic material member 42 made of a rolled material. 11, the reluctance torque can be increased by arranging a direction having a relatively high initial permeability in the circumferential direction of the rotor 11, that is, the rotation direction of the rotor 11, and further, hysteresis loss, back torque, cogging torque, drag loss, and operation Generation of noise and vibration at the time can be reduced.
Further, in the radially inner region and the radially outer region, the magnet torque can be increased by arranging the direction having a relatively high initial permeability in the rotation axis O direction (that is, the magnetic path gap direction), Since the combined torque obtained by combining the reluctance torque and the magnet torque can be increased, the operation efficiency of the axial gap motor 10 can be improved.

In the above-described embodiment, the pair of stators 12 and 12 are provided so as to face each other so as to sandwich the rotor 11 from both sides in the direction of the rotation axis O. However, the present invention is not limited to this. Only one of the stators 12 may be provided.
In the above-described embodiment, the main magnet pole portion 31 includes a pair of magnetic material members 42 and 42 that sandwich the main permanent magnet piece 41 from both sides in the thickness direction, and the sub magnet portion 32 extends in the direction of the rotation axis O. The pair of secondary permanent magnet pieces 43, 43 sandwiching the radial rib 34 from both sides are provided, but the present invention is not limited to this. 43 may be provided.

It is a perspective view of an axial gap type motor concerning one embodiment of the present invention. It is a disassembled perspective view of the rotor of the axial gap type motor which concerns on one Embodiment of this invention. It is a principal part disassembled perspective view of the rotor of the axial gap type motor which concerns on one Embodiment of this invention. It is principal part sectional drawing with respect to the radial direction of the axial gap type motor which concerns on one Embodiment of this invention. It is a principal part perspective view of the axial gap type motor which concerns on one Embodiment of this invention. It is a figure which shows the DC magnetization curve in each direction relative to the rolling direction of the magnetic material member of the axial gap type motor which concerns on one Embodiment of this invention. It is a figure which shows the change of the torque according to the phase current advance angle of the axial gap type motor which concerns on the Example and comparative example which concern on one Embodiment of this invention.

Explanation of symbols

10 Axial gap type motor 11 Rotor 12 Stator (stator, first stator, second stator)
22 Teeth 23 Slot 41 Main permanent magnet piece (Main permanent magnet)
42 Magnetic material members (magnetic members)
43 secondary permanent magnet pieces (secondary permanent magnet, first secondary permanent magnet, second secondary permanent magnet)

Claims (3)

An axial gap type motor comprising: a rotor rotatable around a rotation axis; and a stator disposed opposite to the rotor from at least one side in a rotation axis direction parallel to the rotation axis of the rotor,
The rotor includes a plurality of main permanent magnets arranged in a circumferential direction with a magnetization direction in the rotation axis direction, and a direction in which the magnetization direction is perpendicular to the rotation axis direction and in the vicinity of the end of the main permanent magnet. A plurality of sub-permanent magnets arranged, and a magnetic member arranged on the surface of at least one side of the main permanent magnet in the rotational axis direction between the two sub-permanent magnets adjacent in the circumferential direction,
The magnetic member is made of a rolled material formed by rolling, and the rolling direction in at least the radially inward or radially outward region is the rotational axis direction, and the radially inward and radially outward An axial gap type motor characterized in that the rolling direction in the region between the two is the circumferential direction of the rotor. The rolled material is a magnetic steel sheet,
2. The axial gap motor according to claim 1, wherein the magnetic member is a laminated steel plate in which a plurality of the electromagnetic steel plates are laminated in a radial direction of the rotor. The sub-permanent magnet includes a pair of first sub-permanent magnets and second sub-permanent magnets arranged in the vicinity of both end portions in the rotation axis direction of the main permanent magnet,
The said stator is equipped with a pair of 1st stator and 2nd stator which are opposingly arranged by the said rotating shaft direction, and pinch | interpose the said rotor from the both sides of the said rotating shaft direction. Axial gap type motor.

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