JP5977155B2 - Permanent magnet motor - Google Patents

Description

  The present invention relates to a permanent magnet motor including a rotor having a permanent magnet, and more particularly to a technique capable of maintaining the efficiency of a permanent magnet motor over a wide range of rotational speeds.

  As a device driving device that drives a device (for example, a compressor, a washing machine, a vehicle, a vehicle-mounted device, etc. provided in an air conditioner or a refrigerator), a device driving device including a permanent magnet motor, an inverter device, and a control device is used. ing. As the permanent magnet motor, for example, a rotor having a permanent magnet inserted into a rotor core and a magnet insertion hole formed in a main magnetic pole portion of the rotor core, and inserted into slots of the stator core and the stator core 2. Description of the Related Art Permanent magnet electric motors (referred to as “permanent magnet embedded electric motors”) having a stator having a stator winding are used. Such a permanent magnet motor can utilize both the magnet torque due to the magnetic flux of the permanent magnet provided in the main magnetic pole part and the reluctance torque due to the saliency of the auxiliary magnetic pole part between the main magnetic pole parts.

In the permanent magnet motor, when the amount of magnetic flux of the permanent magnet is constant, the induced voltage (also referred to as “back electromotive voltage”) induced in the stator winding increases in proportion to the rotational speed of the rotor. When the induced voltage induced in the stator winding reaches a predetermined value determined by the power supply voltage or the like, the rotational speed does not increase. Although the rotational speed can be increased from a predetermined value by increasing the power supply voltage, the inverter device becomes expensive and the efficiency of the permanent magnet motor also decreases.
On the other hand, if the amount of magnetic flux of the permanent magnet is reduced so that the rotor can be rotated at a high rotational speed, the efficiency of the permanent magnet motor is reduced when the rotor is rotated at a low rotational speed.

Thus, when the amount of magnetic flux of the permanent magnet is constant, the rotor cannot be rotated over a wide rotational speed range while maintaining the efficiency of the permanent magnet motor.
Therefore, there has been proposed a permanent magnet motor that can maintain efficiency over a wide rotational speed range by changing the amount of magnetic flux of the permanent magnet (see Patent Document 1 and Patent Document 2). The permanent magnet electric motors shown in Patent Document 1 and Patent Document 2 operate the permanent magnet by applying a magnetic field to the permanent magnet in a direction opposite to the magnetization direction of the permanent magnet while the rotor is rotating (during operation). Demagnetize (decrease the amount of magnetic flux of the permanent magnet) or increase the permanent magnet by increasing the permanent magnet by applying a magnetic field to the permanent magnet in the same direction as the magnetization direction of the permanent magnet (increasing the amount of magnetic flux of the permanent magnet) ing.
For example, as shown in FIG. 13, when the rotational speed increases and reaches the set rotational speed K1 in the state where the low speed characteristic 1 (= magnetic flux amount 1) is set, the permanent magnet is demagnetized. (Lower magnetic flux amount) and shift from low speed characteristic 1 to medium speed characteristic 2 (= magnetic flux amount 2 <magnetic flux amount 1). In this state, when the rotational speed further increases and reaches the set rotational speed K2, the permanent magnet is demagnetized, and the medium speed characteristic 2 shifts to the high speed characteristic 3 (= magnetic flux amount 3 <magnetic flux amount 2). Let On the other hand, when the rotational speed decreases and reaches the set rotational speed K2 in the state where the high speed characteristic 3 (= magnetic flux amount 3) is set, the permanent magnet is magnetized (the magnetic flux amount is increased), and the high speed is increased. Transition from characteristic 3 for medium speed to characteristic 2 for medium speed (= magnetic flux amount 2> magnetic flux amount 3). In this state, when the number of rotations further decreases and reaches the set number of rotations K1, the permanent magnet is magnetized to shift from the medium speed characteristic 2 to the low speed characteristic 1 (= magnetic flux amount 1> magnetic flux amount 2). Let Thus, by changing the amount of magnetic flux of the permanent magnet during operation, the efficiency of the permanent magnet motor can be maintained over a wide rotational speed range.

JP 2010-4671 A JP 2010-4672 A

The permanent magnet motor 310 shown in Patent Document 1 and Patent Document 2 has a stator 320 and a rotor 330 as shown in FIGS. 11 and 12. The stator 320 has a tooth 322 and a stator winding inserted in a slot 325 formed by the tooth 322. The rotor 330 has main magnetic pole portions A to D arranged along the circumferential direction, and a permanent magnet 350 is inserted into a magnet insertion hole 340 formed in the main magnetic pole portions A to D.
In the permanent magnet motor 310 shown in Patent Documents 1 and 2, the length (width) along the radial direction of the magnet insertion hole 340 is uniform when viewed in a cross section perpendicular to the axial direction.
For this reason, in order to effectively increase the magnetization of the permanent magnet 350, as shown in FIG. 11, the center in the circumferential direction of the magnet insertion hole 340 (in FIG. 11, the d-axis of the main magnetic pole portions A to D). Of the magnetic poles that generate a magnetic field that acts on the permanent magnet 350 inserted in the magnet insertion hole 340, a position that coincides with the circumferential center of the magnetic pole having a polarity different from that of the permanent magnet 350 (referred to as "magnetic pole center"). In this state, it is necessary to energize the stator winding so that a magnetic field is generated. For example, a magnet insertion hole that is formed in the main magnetic pole portion A and is magnetized to the S pole (the outer magnet is magnetized so that the outer peripheral side becomes the S pole and the inner peripheral side becomes the N pole). The center in the circumferential direction of 340 (d-axis of the main magnetic pole part A) is composed of N poles (teeth e3 to e5) among the magnetic poles that generate a magnetic field acting on the permanent magnet 350 inserted in the magnet insertion hole 340. The magnetic field needs to be generated in the direction indicated by the arrow in FIG.
Further, in order to effectively demagnetize the permanent magnet 350, the circumferential center of the magnet insertion hole 340 acts on the permanent magnet 350 inserted in the magnet insertion hole 340 as shown in FIG. Among the magnetic poles that generate the magnetic field, it is necessary to energize the stator winding so that the magnetic field is generated in a state that coincides with the circumferential center of the magnetic pole having the same polarity as that of the permanent magnet 350. For example, the circumferential center of the magnet insertion hole 340 (d-axis of the main magnetic pole part A) formed in the main magnetic pole part A and into which the permanent magnet 350 magnetized to the S pole is inserted is the teeth e3 to e3. A position that is 180 degrees apart in electrical angle along the direction opposite to the rotation direction of the rotor 330 (direction of arrow R) from the circumferential center of the N-pole magnetic pole constituted by e5 [position of electrical angle 0 degree]. It is necessary to generate a magnetic field in the direction indicated by the arrow in FIG.
Furthermore, the value of the current that flows through the stator winding when the permanent magnet is magnetized or demagnetized is the square of the width (length along the radial direction) of the magnet insertion hole in which the permanent magnet is inserted. Since it is proportional, a large current (for example, 8 to 10 times the rated current) flows even when magnetizing is performed at [electrical angle 0 ° position] or when demagnetizing is performed at [electrical angle 180 ° position]. There is a need. For this reason, it is necessary to use an inverter device having a large current capacity, and the cost of the device driving device increases.
The present invention was devised in view of such points, and the stator provided in the stator when the permanent magnet provided in the rotor of the permanent magnet motor is magnetized or demagnetized. It aims at providing the technique which can reduce the electric current sent through a coil | winding.

The permanent magnet motor of the present invention has a stator and a rotor. The stator is formed by a yoke extending along the circumferential direction, a plurality of teeth extending along the radial direction from the yoke, and teeth adjacent in the circumferential direction when viewed in a cross section perpendicular to the axial direction. A stator winding is inserted into the slot. The teeth have a teeth base portion extending in the radial direction from the yoke, and a teeth tip portion extending from the tip portion of the teeth base portion to both sides in the circumferential direction. A tooth tip surface is formed by the tip surface of the tooth base and the rotor-side surface of the tooth tip. The rotor has a plurality of main magnetic pole portions arranged along the circumferential direction when viewed in a cross section perpendicular to the axial direction. A magnet insertion hole is formed in the main magnetic pole portion, and a permanent magnet is inserted in the magnet insertion hole.
In the present invention, the magnet insertion hole has first to third magnet insertion portions, and the permanent magnet has first to third permanent magnet portions inserted into the first to third magnet insertion portions, respectively. Have. The first to third magnet insertion portions may be magnet insertion holes formed individually, or may be different portions of one magnet insertion hole. The first to third permanent magnet portions may be individually formed permanent magnets or different portions of one permanent magnet.
When viewed in a cross section perpendicular to the axial direction, the first magnet insertion portion and the third magnet insertion portion are disposed on both sides of the second magnet insertion portion along the circumferential direction. Further, the length (width) along the radial direction of the second magnet insertion portion is along the length (width) along the radial direction of the first magnet insertion portion and the radial direction of the third magnet insertion portion. It is configured to be shorter than the length (width). The length (width) along the radial direction of the first magnet insertion portion and the third magnet insertion portion may be the same (including “substantially the same”) or may be different. The cross-sectional shape of the first to third permanent magnet portions is preferably formed in the same shape (including “substantially the same shape”) as the cross-sectional shape of the first to third magnet insertion portions. It is not limited.
Furthermore, the opening angle θ degree (electrical angle) between the first magnet insertion part and the third magnet insertion part and the opening angle α degree (electrical angle) of the tip surface of the tooth base are [25 degrees (electrical angle)]. <Θ degrees (electrical angle) <25 degrees (electrical angle) + α (electrical angle) / 2] is satisfied. Note that the opening angle θ between the first magnet insertion portion and the third magnet insertion portion and the opening angle α of the tooth tip surface of the tooth base are opening angles with the center point of the rotor as the center.
In this invention, it is arrange | positioned between the 1st magnet insertion part and the 3rd magnet insertion part along the circumferential direction, and has a width shorter than the width of the 1st magnet insertion part and the width of the 3rd magnet insertion part. By magnetizing or demagnetizing the second permanent magnet portion inserted in the second magnet insertion portion, the efficiency of the permanent magnet motor can be maintained over a wide rotational speed range, and magnetizing or demagnetizing can be performed. It is possible to reduce the current flowing through the stator winding when performing the above.
In the different form of this invention, the bridge | bridging part is provided between the 1st magnet insertion part and the 2nd magnet insertion part, and between the 2nd magnet insertion part and the 3rd magnet insertion part. In this embodiment, individually formed magnet insertion holes are used as the first to third magnet insertion portions, and individually formed permanent magnets are used as the first to third permanent magnet portions. .
In this embodiment, since the bridge portion is provided between the second magnet insertion portion and the first and third magnet insertion portions, the strength of the rotor is increased.
In another different aspect of the present invention, the second magnet insertion portion is disposed at a position intersecting with the d-axis of the main magnetic pole portion when viewed in a cross section perpendicular to the axial direction.
In another different aspect of the present invention, the second magnet insertion portion is configured to have a line-symmetric shape with the d-axis of the main magnetic pole portion as the center line when viewed in a cross section perpendicular to the axial direction. .
In another different form of the present invention, the length (width) along the radial direction of the first magnet insertion portion and the third magnet insertion portion is set to the same (including “substantially the same”) length Lmm, The length (width) Mmm along the radial direction of the second magnet insertion portion is configured to satisfy [Mmm <Lmm / 3].
The current that flows through the stator winding when magnetizing or demagnetizing the permanent magnet is proportional to the square of the thickness of the magnet insertion hole in which the permanent magnet is inserted. For this reason, in this embodiment, when the permanent magnet is magnetized or demagnetized, the current flowing through the stator winding can be reduced to about 10% as compared with the case where a magnet insertion hole having a uniform width is used. .
In another different aspect of the present invention, the first permanent magnet portion and the third permanent magnet portion extend along an arc centered on the center point of the rotor when viewed in a cross section perpendicular to the axial direction. Is formed.

  In the present invention, when the permanent magnet provided in the rotor of the permanent magnet motor is magnetized or demagnetized, the current flowing through the stator winding provided in the stator can be reduced.

It is sectional drawing perpendicular to the axial direction of 1st Embodiment of the permanent magnet electric motor of this invention. FIG. 3 is a partially enlarged view of FIG. 2. The opening angle θ (electrical angle) between the first magnet insertion portion and the third magnet insertion portion, the efficiency of the permanent magnet motor, and the current passed through the stator winding when the permanent magnet is magnetized or demagnetized It is a figure which shows the relationship. The figure which shows the state which the circumferential direction center of a 2nd magnet insertion part exists in the center [electrical angle 0 degree position] of the magnetic pole of a different polarity from the 2nd permanent magnet part inserted in the 2nd magnet insertion part. It is. The circumferential center of the second magnet insertion portion exists at a position [electrical angle 45 ° position] that is 45 degrees away from the [electrical angle 0 ° position] position along the direction opposite to the rotation direction of the rotor. It is a figure which shows the state to do. The circumferential center of the second magnet insertion portion exists at a position [electrical angle 90 ° position] that is 90 degrees away from the [electrical angle 0 ° position] position along the direction opposite to the rotation direction of the rotor. It is a figure which shows the state to do. The center in the circumferential direction of the second magnet insertion portion exists at a position [electrical angle 135 ° position] away from the [electrical angle 0 ° position] position by an electric angle of 135 ° along the direction opposite to the rotation direction of the rotor. It is a figure which shows the state to do. The center in the circumferential direction of the second magnet insertion portion exists at a position [electrical angle 180 degree position] that is 180 degrees away from the [electrical angle 0 degree position] position along the direction opposite to the rotation direction of the rotor. It is a figure which shows the state to do. It is a schematic block diagram of one Embodiment of the apparatus drive device using the permanent magnet electric motor of this invention. It is the elements on larger scale of sectional drawing orthogonal to the axial direction of 2nd Embodiment of the permanent magnet electric motor of this invention. It is a figure explaining the operation | movement which magnetizes the conventional permanent magnet motor. It is a figure explaining the operation | movement which demagnetizes the conventional permanent magnet electric motor. It is a figure which shows the state from which the characteristic of a permanent magnet electric motor changes by magnetizing or demagnetizing a permanent magnet.

Embodiments of a permanent magnet motor according to the present invention will be described below with reference to the drawings.
In this specification, the “axial direction” refers to the direction of the rotation center line passing through the center point (rotation center point) P of the rotor in a state where the rotor is rotatably supported with respect to the stator. Show. In addition, the “circumferential direction” refers to the center point P of the rotor as viewed in a cross section perpendicular to the axial direction (direction of the rotation center line) in a state where the rotor is rotatably supported with respect to the stator. Indicates the circumferential direction. Further, the “radial direction” refers to a center point P of the rotor as viewed in a cross section perpendicular to the axial direction (direction of the rotation center line) in a state where the rotor is rotatably supported with respect to the stator. Indicates direction.
Further, the “d-axis” refers to a center along the circumferential direction of the main magnetic pole portion (for example, along the circumferential direction of the portion corresponding to the main magnetic pole portion of the outer peripheral surface of the rotor) when viewed in a cross section along the axial direction. Center line) and the rotor center point P of the rotor 30, and the “q-axis” is the center along the circumferential direction of the auxiliary magnetic pole part between the main magnetic pole parts (for example, the outer circumference of the rotor) Of the surface corresponding to the outer peripheral surface of the auxiliary magnetic pole portion in the circumferential direction) and the rotation center point P of the rotor 30.

A permanent magnet motor 10 according to a first embodiment is shown in FIGS. 1 and 2. FIG. 1 is a cross-sectional view perpendicular to the axial direction of the permanent magnet motor 10 of the first embodiment, and FIG. 2 is a partially enlarged view of FIG. The permanent magnet motor 10 according to the present embodiment is configured as a permanent magnet embedded motor.
The permanent magnet motor 10 of the present embodiment has a stator 20 and a rotor 30.
The stator 20 includes a stator core formed by laminating electromagnetic steel plates and a stator winding. The stator 20 includes a yoke 21 extending along the circumferential direction when viewed in a cross section perpendicular to the axial direction, and a plurality of teeth 22 extending from the yoke 21 along the radial direction toward the center point of the rotor 30. Have. The teeth 22 have a teeth base portion 23 extending from the yoke 21 along the radial direction, and a teeth tip portion 24 extending from the tip portion of the teeth base portion 23 along both sides in the circumferential direction. A tooth tip surface 22a is formed by the tip surface of the tooth base 23 and the surface of the tooth tip 24 facing the rotor 30. A rotor accommodating section for accommodating the rotor 30 is formed by the tooth tip surface 22a. A stator winding is inserted into a slot 25 formed by teeth 22 adjacent in the circumferential direction. In the present embodiment, the stator winding is inserted into the slot 25 by a distributed winding method.

The rotor 30 is composed of a rotor core and a permanent magnet formed by laminating electromagnetic steel plates. The rotor 30 has main magnetic pole portions A to D arranged along the circumferential direction when viewed in a cross section perpendicular to the axial direction. A magnet insertion hole 40 extending in the axial direction is formed in the main magnetic pole portions A to D, and a permanent magnet 50 is inserted into the magnet insertion hole 40. The permanent magnet 50 is magnetized so that adjacent main magnetic pole portions have different polarities. The permanent magnet 50 is magnetized along the radial direction. The magnet insertion hole 40 has first to third magnet insertion holes 41 to 43. The permanent magnet 50 inserted into the magnet insertion hole 40 has first to third permanent magnets 51 to 53 inserted into the first to third magnet insertion holes 41 to 43, respectively.
A rotating shaft 60 is inserted into a rotating shaft insertion hole formed on the center side of the rotor 30. In the present embodiment, the rotor 30 rotates in the direction of the arrow (clockwise) R shown in FIG.

In the present embodiment, the magnet insertion hole 40 has a first magnet insertion hole 41, a second magnet insertion hole 42, and a third magnet insertion hole 43. The first magnet insertion hole 41 and the third magnet insertion hole 43 are disposed on both sides of the second magnet insertion hole 42 along the circumferential direction.
A bridge 44 a is formed between the first magnet insertion hole 41 and the second magnet insertion hole 42, and a bridge 44 b is formed between the second magnet insertion hole 42 and the third magnet insertion hole 43. Yes. The strength of the rotor 30 is increased by the bridges 44a and 44b. The bridges 44a and 44b have a short length along the circumferential direction (the interval between the second magnet insertion hole 42 and the first and third magnet insertion holes 41 and 43). When magnetic flux flows through the magnetic field, it immediately becomes magnetically saturated. For this reason, the magnetic flux flowing through the bridges 44a and 44b can be ignored. The bridges 44a and 44b correspond to the “bridge portion” of the present invention.
A passage 45ab constituting the auxiliary magnetic pole part AB is formed between the third magnet insertion hole 43 of the main magnetic pole part A and the first magnet insertion hole 41 of the main magnetic pole part B adjacent to the main magnetic pole part A. . Similarly, a passage 45bc (not shown) constituting the auxiliary magnetic pole part BC is formed between the main magnetic pole part B and the main magnetic pole part C, and the auxiliary magnetic pole part C is interposed between the main magnetic pole part C and the main magnetic pole part D. A passage 45cd (not shown) constituting the portion CD is formed, and a passage 45da constituting the auxiliary magnetic pole portion DA is formed between the main magnetic pole portion D and the main magnetic pole portion A.
In the present embodiment, the first magnet insertion hole 41 corresponds to the “first magnet insertion portion” of the present invention, and the second magnet insertion hole 42 corresponds to the “second magnet insertion portion” of the present invention. The third magnet insertion hole 43 corresponds to the “third magnet insertion portion” of the present invention.

  The first magnet insertion hole 41 is disposed on the inner side in the radial direction when viewed in a cross section perpendicular to the axial direction, and is disposed on the outer side in the radial direction, extending along the circumferential direction, and along the circumferential direction. The outer peripheral wall 41b extending along the circumferential direction is disposed on the side opposite to the rotational direction R (q-axis side), and extends along the radial direction on the side wall 41c, on the rotational direction R side (d-axis side). The side wall 41d is disposed and extends along the radial direction. Similarly, the second magnet insertion hole 42 is formed by an inner peripheral wall 42a, an outer peripheral wall 42b, and side walls 42c and 42d. The third magnet insertion hole 43 is formed by an inner peripheral wall 43a, an outer peripheral wall 43b, and side walls 43c and 43d.

The first to third permanent magnets 51 to 53 inserted into the first to third magnet insertion holes 41 to 43 respectively have first to third magnet insertion holes 41 to 43 having a cross section perpendicular to the axial direction. (Including "substantially the same"). That is, the first to third permanent magnets 51 to 53 have inner peripheral walls 51a to 53a, outer peripheral walls 51b to 53c, side walls 51c to 53c, and 51d to 53d as viewed in a cross section perpendicular to the axial direction. . In the present embodiment, the first to third permanent magnets 51 to 53 are formed of a ferrite magnet or a samarium cobalt magnet. Of course, the 1st-3rd permanent magnets 51-53 can be formed with the magnet of another material. Moreover, the 1st-3rd permanent magnets 51-53 can also be formed with the magnet of a different material.
In the present embodiment, inner peripheral walls 41a and 43a and outer peripheral walls 41b and 43b of the first magnet insertion hole 41 and the third magnet insertion hole 43 (the inner peripheral walls of the first permanent magnet 51 and the third permanent magnet 53). 51a and 53a and outer peripheral walls 51b and 53b) are formed in a circular arc shape with the rotation center point P of the rotor 30 as the center. That is, the first magnet insertion hole 41 and the third magnet insertion hole 43 (the first permanent magnet 51 and the third permanent magnet 53) are along an arc centered on the rotation center point P of the rotor 30. It extends. Further, in the second magnet insertion hole 42 (second permanent magnet 52), the inner peripheral wall 42a and the outer peripheral wall 42b (the inner peripheral wall 52a and the outer peripheral wall 52b) are orthogonal to the d-axis of the main magnetic pole portions AD (" Extending in a direction including “substantially orthogonal”. That is, the second magnet insertion hole 42 (second permanent magnet 52) extends linearly in a direction orthogonal to the d-axis.
The second magnet insertion hole 42 (second permanent magnet 52) is arranged so as to intersect (orthogonal) the d axis, and the first to third magnet insertion holes 41 to 43 (first to third). The permanent magnets 51 to 53) are formed so as to be line-symmetrical (including “substantially line-symmetrical”) with the d axis as a center line.

Further, when viewed in a cross section perpendicular to the axial direction, the length (width) along the radial direction of the second magnet insertion hole 42 is the radial direction of the first magnet insertion hole 41 and the third magnet insertion hole 43. It is comprised so that it may become shorter than the length (width) along.
In the present embodiment, the width of the first magnet insertion hole 41 and the width of the third magnet insertion hole 43 are set to the same width (including “substantially the same”) Lmm. The width Mmm of the second magnet insertion hole 42 is set so as to satisfy [Mmm <Lmm / 3].
When the permanent magnet provided in the rotor is magnetized or demagnetized using a magnetic field generated by passing a current through the stator winding, the width of the magnet insertion hole into which the permanent magnet is inserted is 2 It is necessary to pass a current proportional to the power. In the present embodiment, the width Lmm of the first magnet insertion hole 41 and the third magnet insertion hole 43 and the width Mmm of the second magnet insertion hole 42 are set so as to satisfy [Mmm <Lmm / 3]. Therefore, when the permanent magnet is magnetized or demagnetized, the current flowing through the stator winding can be reduced to (1/3) ² or less, that is, about 10%. .

Next, the opening angle θ between the first magnet insertion hole 41 and the third magnet insertion hole 43, the efficiency of the permanent magnet electric motor 10, and the permanent magnet are passed through the stator winding when magnetizing or demagnetizing. The result of examining the relationship with the current will be described with reference to FIG. As shown in FIG. 2, the opening angle θ is set between the first magnet insertion hole 41 and the third magnet insertion hole 43 (the first magnet insertion hole 41 on the d-axis side end wall 41d and the first magnet insertion hole 41). 3, the width along the circumferential direction of the third magnet insertion hole 43 (between the end walls 43 c on the d-axis side) is represented by an angle (electrical angle) centered on the rotation center point P of the rotor 30. If the line extending along at least one of the end wall 41d of the first magnet insertion hole 41 and the end wall 43c of the third magnet insertion hole 43 does not pass through the center point P of the rotor 30, the minimum The opening angle is defined as an opening angle θ between the first magnet insertion hole 41 and the third magnet insertion hole 43.
In FIG. 3, the horizontal axis represents the opening angle θ (electrical angle), the left vertical axis represents the current (A) that flows through the stator winding when the permanent magnet is magnetized or demagnetized, and the right vertical axis Indicates the efficiency (%) of the permanent magnet motor 10. Also, the dashed curve shows the change in current with respect to the opening angle θ, and the solid line shows the change in efficiency with respect to the opening angle θ.
From FIG. 3, when the opening angle θ between the first magnet insertion hole 41 and the third magnet insertion hole 43 exceeds an electrical angle of 25 degrees, the current flowing through the stator winding decreases (permanent with a small current). It can be understood that the magnet can be magnetized or demagnetized). Further, it can be understood that the efficiency of the permanent magnet motor 10 decreases when the opening angle θ is equal to or greater than [25 degrees (electrical angle) + opening angle α (electrical angle) / 2 of the tip surface of the tooth base]. As shown in FIG. 1, the “open angle α of the tip surface of the tooth base” is an angle (electricity) about the width W of the tip surface of the teeth base 23 around the rotation center point P of the rotor 30. (Corner). Specifically, when viewed in a cross section perpendicular to the axial direction, an opening between points where the lines along the wall surfaces on both sides in the circumferential direction of the tooth base 23 intersect the teeth tip surface 22a (points indicated by black circles). It is a horn.
From the above, the opening angle θ between the first magnet insertion hole 41 and the third magnet insertion hole 43 is [25 degrees (electrical angle) <θ degrees (electrical angle) <25 degrees (electrical angle) + By satisfying the opening angle α (electrical angle) / 2] of the tip surface of the tooth base, the permanent magnet is supplied to the stator winding when the permanent magnet is magnetized or demagnetized while maintaining the efficiency of the permanent magnet motor 10. The current can be reduced.
As described above, since the bridges 44a and 44b have a short length along the circumferential direction, they are easily magnetically saturated. For this reason, the magnetic flux flowing through the bridges 44a and 44b can be ignored.

Next, a schematic configuration of an embodiment of a device driving apparatus that drives a device using the permanent magnet motor of the present invention will be described with reference to FIG.
The device driving apparatus according to the present embodiment includes a permanent magnet motor 110, an inverter device 160, and a control device 170.
The inverter device 160 is configured to be able to sequentially energize the stator winding 126 provided on the stator of the permanent magnet motor 110 using a switching element such as an FET. As the inverter device 160, an inverter device capable of converting an AC voltage into a DC voltage and sequentially applying the DC voltage to the stator winding 126, or an inverter device capable of sequentially applying a DC voltage to the stator winding 126 is used. . As the inverter device 160, those having various known configurations can be used.
The control device 170 controls the inverter device 160 based on the position of the rotor so that the rotor of the permanent magnet motor 110 rotates in a predetermined rotation direction. In the present embodiment, control device 170 detects the position of the rotor using an induced voltage induced in stator winding 126 (referred to as “sensorless method”).
In addition, when using a sensorless system, the position of the rotor at the time of a stop is unknown. For this reason, at the time of starting, the inverter device 160 is controlled to start after a minute current is passed through the stator winding 126 to set the rotor position to a predetermined position. Of course, a position detector (for example, a Hall element) that detects the position of the rotor can also be used. In this case, the position setting process at the time of starting is not necessary.

Further, the control device 170 is provided in the rotor by a magnetic field generated by energizing the stator windings so that the rotation speed can be changed over a wide range while maintaining efficiency. The inverter device 160 is controlled so that the permanent magnet is magnetized (the amount of magnetic flux increases) or demagnetized (the amount of magnetic flux decreases).
For example, in a state where the magnetic flux amount of the permanent magnet is set to the magnetic flux amount corresponding to the low speed characteristic 1 shown in FIG. The inverter device 160 is controlled so that the magnetic field generated by energization of the winding 126 is generated at a timing at which the magnetic field is generated in a direction opposite to the magnetization direction of the permanent magnet. As a result, the permanent magnet is demagnetized to reduce the amount of magnetic flux, and the medium speed characteristic 2 is set. In this state, when the rotational speed further increases and reaches the set rotational speed K2, the magnetic field is generated at the timing when the magnetic field generated by energization of the stator winding 126 acts in the direction opposite to the magnetization direction of the permanent magnet. Thus, the inverter device 160 is controlled. As a result, the permanent magnet is demagnetized to further reduce the amount of magnetic flux, and the characteristic 3 for high speed is set.
On the other hand, when the rotational speed decreases and reaches the set rotational speed K2 in a state where the magnetic flux amount of the permanent magnet is set to the magnetic flux amount corresponding to the high-speed characteristic 3, it is generated by energization of the stator winding 126. The inverter device 160 is controlled so that the magnetic field is generated at the timing when the magnetic field acts in the same direction as the magnetization direction of the permanent magnet. As a result, the permanent magnet is magnetized to increase the amount of magnetic flux, and the medium speed characteristic 2 is set. In this state, when the rotational speed further decreases and reaches the set rotational speed K1, the magnetic field is generated at the timing when the magnetic field generated by energization of the stator winding 126 acts in the same direction as the magnetization direction of the permanent magnet. Thus, the inverter device 160 is controlled. As a result, the permanent magnet is magnetized, the amount of magnetic flux is increased, and the low speed characteristic 1 is set.
As a method for generating a magnetic field for increasing or decreasing the magnetization of a permanent magnet, for example, a method in which a stator winding is energized for a short time (pulse energization) at the timing of generating a magnetic field is used.

As described above, when the permanent magnet inserted in the magnet insertion hole having a uniform width is magnetized, as shown in FIG. 11, the stator winding is at [electrical angle 0 degree position]. When demagnetizing and demagnetizing, as shown in FIG. 12, it is necessary to energize the stator winding at [electrical angle 180 degree position]. Here, in the permanent magnet motor using both the magnet torque due to the magnetic flux of the permanent magnet provided in the main magnetic pole part and the reluctance torque due to the saliency of the auxiliary magnetic pole part between the main magnetic pole parts, the circumferential direction of the magnet insertion hole When the stator winding is energized with the center (d-axis) existing at [electrical angle 0 degree position] and [electrical angle 180 degree position] so that a magnetic field for increasing or demagnetizing the permanent magnet is generated. The torque generated by energizing the stator winding and acting to stop the rotor is large. Further, in such a permanent magnet motor, torque (magnet torque and reluctance torque are added up) when the circumferential center (d-axis) of the magnet insertion hole is at [electrical angle 0 degree position] or [electrical angle 180 degrees]. Synthesized torque) is small. For this reason, when a device having a small inertia force is driven by the device driving device of the present invention, the center in the circumferential direction of the magnet insertion hole is set to [electrical angle 0 degree position] or [electrical angle 180 degree position] during operation. When the stator winding is energized so that a magnetic field for increasing or demagnetizing the permanent magnet is generated in the existing state, the rotor may stop.
In the device driving apparatus using the permanent magnet motor of the present embodiment, the permanent magnet can be magnetized or demagnetized at a position other than [electrical angle 0 degree position] or [electrical angle 180 degree position] and fixed. Since the current flowing through the child winding can be reduced, there is no possibility that the rotor stops when the permanent magnet is magnetized or demagnetized during operation.

In the following, in the state where the device is driven by the device drive device using the permanent magnet motor of the present embodiment, the operation of magnetizing or demagnetizing the permanent magnet provided in the rotor of the permanent magnet motor, This will be described with reference to FIGS.
In the following, for the sake of simplicity of explanation, a permanent magnet provided on the main magnetic pole portion A of the rotor 30 and magnetized on the S pole (the S pole on the outer peripheral side and the N pole on the inner peripheral side), and the teeth e3 Description will be made by paying attention to the magnetic field generated by the magnetic pole formed by .about.e5. Note that the stator windings g1 and g2 inserted in the slots f1 and f2 formed in the direction opposite to the rotation direction R of the rotor 30 from the teeth e3 to e5 are provided in the direction from the front side to the back side of the page ( Current flows through the teeth e3 to e5, and the stator windings g5 and g6 inserted in the slots f5 and f6 formed on the rotor 30 in the rotation direction R side from the teeth e3 to e5 are connected to the front side from the back side of the drawing. The magnetic poles formed by the teeth e3 to e5 when the current flows in the direction (●) indicate N poles among the magnetic poles that generate the magnetic field. The center line along the radial direction of the tooth base 23 of the tooth e4 is defined as the center (magnetic pole center) of the magnetic pole formed by the teeth e3 to e5.

FIG. 4 shows a state in which the circumferential center (d-axis in the present embodiment) of the second magnet insertion hole 42 of the main magnetic pole portion A exists at the magnetic pole center [electrical angle 0 degree position]. In the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 0 degree position], the magnetic field generated by the magnetic pole is as shown by the arrow in FIG. It acts on the second permanent magnet 52 having a small thickness in the same direction as the magnetization direction of the permanent magnet 52 via the teeth e4 arranged at the magnetic pole center. Accordingly, in the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at the [electrical angle 0 degree position], the current flowing through the stator windings g1, g2, and g5, g6 is reduced. The second permanent magnet 52 can be magnetized.
5 shows that the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole part A is electrically operated along a direction (counterclockwise) opposite to the rotation direction R of the rotor 30 from [electrical angle 0 degree position]. It shows a state that exists at a position [electrical angle 45 degrees position] that is 45 degrees apart. In the state in which the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at the [electrical angle of 45 degrees position], the magnetic field generated by the magnetic pole is as shown by an arrow in FIG. It acts on the second permanent magnet 52 having a small thickness in the same direction as the magnetization direction of the permanent magnet 52 via the teeth e3 that are separated from the center of the magnetic pole in the direction opposite to the rotation direction R. Accordingly, in the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 45 ° position], the current flowing through the stator windings g1, g2, and g5, g6 is reduced. The second permanent magnet 52 can be magnetized.

In a state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole part A exists in the direction opposite to the rotation direction R from the [electrical angle 45 ° position], the magnetic field generated by the magnetic poles It does not act on the second permanent magnet 52 with a small thickness, but acts on the third permanent magnet 53 with a large thickness in the same direction as the magnetization direction of the permanent magnet 53. Alternatively, the main magnetic pole portion B adjacent to the main magnetic pole portion A on the rotation direction R side is magnetized to the north pole, and the first permanent magnet 51 having a large thickness is opposite to the magnetization direction of the permanent magnet 51. Acts in the direction of
For example, in FIG. 6, the circumferential center of the second magnet insertion hole 42 of the main magnetic pole portion A is 90 degrees in electrical angle from the [electrical angle 0 degree position] along the direction opposite to the rotational direction R of the rotor. The state which exists in the distant position [electrical angle 90 degree position] is shown. In the state in which the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 90 ° position], the magnetic field generated by the magnetic pole is as shown by an arrow in FIG. It acts on the third permanent magnet 53 of the main magnetic pole portion A in the same direction as the magnetization direction of the permanent magnet 53 via the teeth e3 that are separated from the center of the magnetic pole in the direction opposite to the rotation direction R. Further, it acts on the first permanent magnet 51 of the main magnetic pole portion B in the direction opposite to the magnetization direction of the permanent magnet 51 via the teeth e5 that are separated from the magnetic pole center in the rotation direction R side.
Therefore, the current is fixed to the extent that the second permanent magnet 52 is magnetized or demagnetized in the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 0 degree position]. Even if it flows through the child windings g1, g2, and g5, g6, the third permanent magnet column 53 of the main magnetic pole portion A cannot be magnetized or the first permanent magnet 51 of the main magnetic pole portion B cannot be demagnetized.
In order to increase the magnetism of the third permanent magnet 53 of the main magnetic pole part A or demagnetize the first permanent magnet 51 of the main magnetic pole part B, a current flowing through the stator windings g1, g2 and g5, g6 is used. Need to increase.

FIG. 7 shows that the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A is separated by 135 degrees in electrical angle along the direction opposite to the rotation direction R of the rotor 30 from [electrical angle 0 degree position]. A state existing at the position [electrical angle 135 ° position] is shown. In the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 135 ° position], the magnetic field generated by the magnetic pole is as shown by an arrow in FIG. The second permanent magnet 52 of the main magnetic pole portion B adjacent to the main magnetic pole A on the rotation direction R side is connected to the magnetization direction of the permanent magnet 52 via the teeth e5 that are separated from the magnetic pole center in the rotation direction R side. Acts in the opposite direction. Accordingly, in the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 135 ° position], the current flowing through the stator windings g1, g2, and g5, g6 is reduced. The second permanent magnet 52 can be demagnetized.
FIG. 8 shows that the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole part A is 180 degrees away from the [electrical angle 0 degree position] along the direction opposite to the rotational direction R of the rotor 30 by an electrical angle. The state existing at the position [electrical angle 180 degree position] is shown. In a state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 180 ° position], the magnetic field generated by the magnetic pole is as shown by an arrow in FIG. The second permanent magnet 52 of the main magnetic pole portion B adjacent to the main magnetic pole A on the rotation direction R side is opposite to the magnetization direction of the permanent magnet 52 through the teeth e4 arranged at the magnetic pole center. Works. Therefore, in the state where the center in the circumferential direction of the second magnet insertion hole 42 of the main magnetic pole portion A exists at [electrical angle 180 ° position], the current flowing through the stator windings g1, g2, and g5, g6 is reduced. The second permanent magnet 52 can be demagnetized.

From the above, the permanent magnet provided in the rotor of the permanent magnet motor is reduced while the current flowing through the stator winding is reduced by configuring the device driving apparatus using the permanent magnet motor of the present embodiment. It is understood that the magnet can be increased or decreased.
That is, when the permanent magnet is magnetized, the circumferential center (d-axis) of the second permanent magnet 52 is the circumferential center of the magnetic pole generating a magnetic field and having a polarity different from that of the second permanent magnet 52. (For example, the magnetic pole center of the magnetic pole formed by the teeth e3 to e5) is a first position [electrical angle 0 degree position] and a rotation direction determined from the first position [electrical angle 0 degree position] (for example, Inverter device 160 is controlled such that a magnetic field is generated in a state of being present between a second position [electrical angle 45 ° position] separated by 45 ° in electrical angle along a direction opposite to rotational direction R). As a result, the permanent magnet can be magnetized while reducing the current flowing through the stator winding.
Further, when demagnetizing the permanent magnet, the circumferential center of the second permanent magnet 52 is an electrical angle along a direction opposite to the rotation direction determined from the first position [position of electrical angle 0 degree]. A third position separated by 135 degrees [electrical angle 135 degrees position] and a fourth position separated by 180 degrees in electrical angle along a direction opposite to the rotation direction determined from the first position [electrical angle 0 degree position]. Inverter device 160 is controlled such that a magnetic field is generated in a state where the electrical angle exists between 180 electrical positions. Thereby, a permanent magnet can be demagnetized, reducing the electric current sent through a stator coil | winding.

Next, a permanent magnet motor according to a second embodiment will be described with reference to FIG. FIG. 10 is a partially enlarged view of a cross-sectional view perpendicular to the axial direction of the permanent magnet motor of the second embodiment.
The permanent magnet motor of the present embodiment is different from the permanent magnet motor 10 of the first embodiment in the configuration of the magnet insertion hole and the permanent magnet.
In the present embodiment, magnet insertion holes 240 are formed in the main magnetic pole portions A to D. The magnet insertion hole 240 is disposed on the inner side in the radial direction when viewed in a cross section perpendicular to the axial direction and extends along the circumferential direction. The inner peripheral wall 241a extends along the circumferential direction and extends along the circumferential direction. The outer peripheral wall 241b is disposed on the opposite side to the rotational direction R along the circumferential direction, and is disposed on the rotational direction R side along the circumferential direction, and the side wall 241c is disposed along the circumferential direction, and extends along the radial direction. The side wall 241d is formed.
The inner peripheral wall 241a has a first inner peripheral wall 241a1, a first step wall 241a2, a second inner peripheral wall 241a3, a second step wall 241a4, and a third inner peripheral wall 241a5. The first inner peripheral wall 241 a 1 and the third inner peripheral wall 241 a 5 are arranged along an arc centered on the rotation center point P of the rotor 230. The second inner peripheral wall 241a3 is disposed radially outside the first inner peripheral wall 241a1 and the third inner peripheral wall 241a5 by the first step wall 241a2 and the second step wall 241a4. The second inner peripheral wall 241a3 extends linearly in a direction orthogonal to the d axis (including “substantially orthogonal”).
The outer peripheral wall 241b has a first outer peripheral wall 241b1, a first step wall 241b2, a second outer peripheral wall 241b3, a second step wall 241b4, and a third outer peripheral wall 241b5. The first outer peripheral wall 241 b 1 and the third inner peripheral wall 241 b 5 are arranged along an arc centered on the rotation center point P of the rotor 230. The second outer peripheral wall 241b3 is disposed radially inward from the first outer peripheral wall 241b1 and the third outer peripheral wall 241b5 by the first step wall 241b2 and the second step wall 241b4. The second outer peripheral wall 241b3 extends linearly in a direction orthogonal to the d-axis (including “substantially orthogonal”).
The first inner peripheral wall 241a1, the first step wall 241a2, the first outer peripheral wall 241b1, the first step wall 241b2, and the side wall 241c form a first magnet insertion portion, and the second inner peripheral wall 241a3 and the second inner wall 241a3. The second magnet insertion portion is formed by the outer peripheral wall 241b3, and the third magnet is formed by the third inner peripheral wall 241a5, the second step wall 241a4, the third outer peripheral wall 241b5, the second step wall 241b4, and the side wall 241d. An insertion part is formed. In the present embodiment, one magnet insertion hole 240 having a first magnet insertion portion, a second magnet insertion portion, and a third magnet insertion portion is formed in the main magnetic pole portions AD.
In the present embodiment, the first magnet insertion portion corresponds to the “first magnet insertion portion” of the present invention, and the second magnet insertion portion corresponds to the “second magnet insertion portion” of the present invention. The third magnet insertion portion corresponds to the “third magnet insertion portion” of the present invention.

A permanent magnet 250 having a cross section perpendicular to the axial direction having the same shape as the magnet insertion hole 240 (including “substantially the same”) is inserted into the magnet insertion hole 240.
The permanent magnet 250 has an inner peripheral wall 251a, an outer peripheral wall 251b, and side walls 251c and 251d when viewed in a cross section perpendicular to the axial direction.
The inner peripheral wall 251a includes a first inner peripheral wall 251a1, a first step wall 251a2, a second inner peripheral wall 251a3, a second step wall 251a4, and a third inner peripheral wall 251a5. The outer peripheral wall 251b includes a first outer peripheral wall 251b1, a first step wall 251b2, a second outer peripheral wall 251b3, a second step wall 251b4, and a third outer peripheral wall 251b5. In a state where the permanent magnet 250 is inserted into the magnet insertion hole 240, the second inner peripheral wall 251a3 is disposed on the radially outer side than the first inner peripheral wall 251a1 and the third inner peripheral wall 251a5. The second outer peripheral wall 251b3 is disposed radially inward from the first outer peripheral wall 251b1 and the third outer peripheral wall 251b5.
The first inner peripheral wall 251a1, the first stepped wall 251a2, the first outer peripheral wall 251b1, the first stepped wall 251b2, and the side wall 251c form a first permanent magnet portion, and the second inner peripheral wall 251a3 and the second The second permanent magnet portion is formed by the outer peripheral wall 251b3, and the third permanent wall is formed by the third inner peripheral wall 251a5, the second step wall 251a4, the third outer peripheral wall 251b5, the second step wall 251b4, and the side wall 251d. A magnet part is formed. In the present embodiment, one permanent magnet 250 having a first permanent magnet portion, a second permanent magnet portion, and a third permanent magnet portion is inserted into one magnet insertion hole 240.
In the present embodiment, the first permanent magnet portion corresponds to the “first permanent magnet portion” of the present invention, and the second permanent magnet portion corresponds to the “second permanent magnet portion” of the present invention. The third permanent magnet portion corresponds to the “third permanent magnet portion” of the present invention.
In the present embodiment, permanent magnet 250 is formed of a ferrite magnet or a samarium cobalt magnet. Of course, the permanent magnet 250 can also be formed of a magnet made of another material.

In the present embodiment, the first inner peripheral wall 241a1, the third inner peripheral wall 241a5, the first outer peripheral wall 241b1 and the third outer peripheral wall 241b5 of the magnet insertion hole 240 (the first inner peripheral wall 251a1 of the permanent magnet 250, The third inner peripheral wall 251 a 5, the first outer peripheral wall 251 b 1, and the third outer peripheral wall 251 b 5) are formed in an arc shape centered on the rotation center point P of the rotor 230. That is, the first magnet insertion portion and the third magnet insertion portion (the first permanent magnet portion and the third permanent magnet portion of the permanent magnet 250) of the magnet insertion hole 240 have the rotation center point P of the rotor 230. It extends along the center arc. Further, the second inner peripheral wall 241a3 and the second outer peripheral wall 243b3 (the second inner peripheral wall 251a3 and the second outer peripheral wall 251b3 of the permanent magnet 250) of the magnet insertion hole 240 are on the d-axis of the main magnetic pole portions A to D. It extends along a direction orthogonal (including “substantially orthogonal”). That is, the second magnet insertion portion of the magnet insertion hole 240 (second permanent magnet portion of the permanent magnet 250) extends linearly in a direction orthogonal to the d-axis.
Similarly to the permanent magnet motor 10 of the first embodiment, the width of the first magnet insertion portion and the width of the third magnet insertion portion are set to the same width (including “substantially the same”) Lmm. ing. The width Mmm of the second magnet insertion portion is set so as to satisfy [Mmm <Lmm / 3].

  In the second embodiment, one permanent magnet 250 having the first to third permanent magnet portions is inserted into one magnet insertion hole 240 having the first to third magnet insertion portions. Individual permanent magnets can also be inserted into the magnet insertion holes 240. For example, as in the first embodiment, the first permanent magnet, the second permanent magnet, and the third permanent magnet may be individually formed and inserted into one magnet insertion hole 240. In this case, the first to third permanent magnets may be formed of magnets of the same material, or may be formed of magnets of different materials.

In the above embodiment, the permanent magnet embedded type electric motor in which the permanent magnet is inserted into the magnet insertion hole formed in the main magnetic pole portion has been described. However, in the present invention, the permanent magnet is arranged on the outer periphery of the rotor. It can also be configured as a surface permanent magnet type motor.
In the third embodiment configured as a surface permanent magnet type electric motor, the permanent magnet is constituted by the first permanent magnet, the second permanent magnet, and the third permanent magnet as in the first embodiment. Is done. The first permanent magnet and the third permanent magnet are arranged on the outer peripheral side of the rotor using a fixing means such as an adhesive. A magnet insertion hole is formed between the first permanent magnet and the third permanent magnet along the circumferential direction, and the second permanent magnet is inserted into the magnet insertion hole. The magnet insertion hole into which the second permanent magnet is inserted has a length (width) along the radial direction of the magnet insertion hole, and a length (thickness) along the radial direction of the first and third permanent magnets. The inner peripheral wall of the magnet insertion hole is located on the outer peripheral side along the radial direction from the inner peripheral walls of the first and third permanent magnets, and the outer peripheral wall of the magnet insertion hole is the first and third permanent magnets. It is comprised so that it may be located in the center side along a radial direction from the outer peripheral wall. A bridge is formed between the magnet insertion hole and the first and third permanent magnets. Open angle θ between the first permanent magnet and the third permanent magnet (between the end wall on the d-axis side of the first permanent magnet and the end wall on the d-axis side of the third permanent magnet), magnet insertion The relationship between the hole width and the thicknesses of the first and third permanent magnets is the same as in the first embodiment.
The permanent magnet motor of the present embodiment can be expressed as follows.
“A stator and a rotor,
The stator includes a yoke extending in a circumferential direction when viewed in a cross section perpendicular to the axial direction, and a plurality of teeth extending in a radial direction from the yoke and having a tooth base portion and a tooth tip portion. , Having a stator winding inserted into a slot formed by circumferentially adjacent teeth;
The rotor includes a plurality of main magnetic pole portions arranged along a circumferential direction when viewed in a cross section perpendicular to the axial direction, and the main magnetic pole portion is a permanent magnet motor provided with a permanent magnet. There,
The permanent magnet has a first permanent magnet portion, a second permanent magnet portion, and a third permanent magnet portion;
The main magnetic pole portion has a magnet insertion hole into which the second permanent magnet portion is inserted,
Seen in a cross section perpendicular to the axial direction,
The first permanent magnet portion, the magnet insertion hole into which the second permanent magnet portion is inserted, and the third permanent magnet portion are sequentially arranged along a circumferential direction;
The length along the radial direction of the magnet insertion hole is configured to be shorter than the length along the radial direction of the first permanent magnet portion and the length along the radial direction of the third permanent magnet portion. Has been
Further, an opening angle between the first permanent magnet portion and the third permanent magnet portion centered on the center point of the rotor is θ degrees (electrical angle), and the center point of the rotor is the center. When the opening angle of the tip surface of the teeth base is α degrees (electrical angle), [25 degrees (electrical angle) <θ degrees (electrical angle) <25 degrees (electrical angle) + α (electrical angle) / 2] It is comprised so that it may satisfy | fill. "
In this case, each configuration described in the above-described embodiment can be expressed in a specified subordinate format.

The present invention is not limited to the configuration described in the embodiment, and various modifications and additions are possible.
The cross section of the first and third magnet insertion portions (first and third permanent magnet portions) is formed in an arc shape, and the cross section of the second magnet insertion portion (second permanent magnet portion) is formed in a linear shape. However, the cross sections of the first to third magnet insertion portions and the first to third permanent magnet portions can be formed in various other shapes. For example, the cross sections of the first to third permanent magnet portions and the first to third permanent magnet portions can be formed in a linear shape.
The first to third permanent magnet portions may be formed of magnets of the same material, or may be formed of magnets of different materials. Moreover, a magnet of various materials can be used as a magnet.
When viewed in a cross section perpendicular to the axial direction, the first to third magnet insertion portions (or the magnet insertion portion into which the second permanent magnet portion is inserted and the first and third permanent magnet portions) are d-axis However, the present invention is not limited to this.
The width Mmm of the second magnet insertion portion is less than 1/3 of the width Lmm of the first and third magnet insertion portions (or the width Mmm of the magnet insertion portion into which the second permanent magnet portion is inserted is The thickness of the third permanent magnet portion is set to less than 1/3 of the thickness Lmm, but the width of the second magnet insertion portion is smaller than the width of the first and third magnet insertion portions (second permanent magnet portion). The width of the magnet insertion portion into which the magnet is inserted is smaller than the thickness of the first and third permanent magnet portions), and can be set as appropriate according to the current capacity of the inverter device.
Although the 1st magnet insertion part and the 3rd magnet insertion part were set to the same width, it is not limited to this. Or although the 1st permanent magnet part and the 3rd permanent magnet part were set as the same width, it is not limited to this.

10, 310 Permanent magnet motor 20, 320 Stator 21, 321 Yoke 22, 322 Teeth 22a Teeth tip surface 23 Teeth base 24 Teeth tip 25, 325 Slot 30 Rotor 41 First magnet insertion hole (first magnet insertion hole) portion)
42 2nd magnet insertion hole (2nd magnet insertion part)
43 3rd magnet insertion hole (3rd magnet insertion part)
44a, 44b Bridges 45ab, 45da, 245ab, 245da Auxiliary magnetic pole portion 51 First permanent magnet (first permanent magnet portion)
52 Second permanent magnet (second permanent magnet portion)
53 Third permanent magnet (third permanent magnet portion)
60 Rotating shaft 110 Permanent magnet motor 126 Stator winding 160 Inverter device 170 Controllers 230 and 330 Rotors 240 and 340 Magnet insertion holes 250 and 350 Permanent magnet 250a First permanent magnet portion 250b Second permanent magnet portion 250c First 3 permanent magnet section

Claims (6)

A stator and a rotor,
The stator includes a yoke extending in a circumferential direction when viewed in a cross section perpendicular to the axial direction, and a plurality of teeth extending in a radial direction from the yoke and having a tooth base portion and a tooth tip portion. , Having a stator winding inserted into a slot formed by circumferentially adjacent teeth;
The rotor has a plurality of main magnetic pole portions arranged in a circumferential direction when viewed in a cross section perpendicular to the axial direction, and a magnet insertion hole is formed in the main magnetic pole portion, and the magnet insertion hole A permanent magnet motor in which a permanent magnet is inserted,
The magnet insertion hole has a first magnet insertion portion, a second magnet insertion portion, and a third magnet insertion portion,
The permanent magnet is inserted into the first permanent magnet portion inserted into the first magnet insertion portion, the second permanent magnet portion inserted into the second magnet insertion portion, and the third magnet insertion portion. A third permanent magnet portion to be
Seen in a cross section perpendicular to the axial direction,
The first magnet insertion portion, the second magnet insertion portion, and the third magnet insertion portion are sequentially arranged along the circumferential direction,
The length along the radial direction of the second magnet insertion portion is shorter than the length along the radial direction of the first magnet insertion portion and the length along the radial direction of the third magnet insertion portion. Is configured as
Further, an opening angle between the first magnet insertion portion and the third magnet insertion portion, centered on the center point of the rotor, is θ degrees (electrical angle), and the center point of the rotor is the center. When the opening angle of the tip surface of the teeth base is α degrees (electrical angle), [25 degrees (electrical angle) <θ degrees (electrical angle) <25 degrees (electrical angle) + α (electrical angle) / 2] It is comprised so that it may satisfy | fill. The permanent magnet motor according to claim 1,
A permanent magnet, wherein a bridge portion is provided between the first magnet insertion portion and the second magnet insertion portion and between the second magnet insertion portion and the third magnet insertion portion. Electric motor. The permanent magnet motor according to claim 1 or 2,
The permanent magnet motor, wherein the second magnet insertion portion is disposed at a position intersecting the d-axis of the main magnetic pole portion when viewed in a cross section perpendicular to the axial direction. The permanent magnet motor according to claim 3,
The permanent magnet electric motor according to claim 1, wherein the second magnet insertion portion has a line-symmetric shape with the d axis of the main magnetic pole portion as a center line when viewed in a cross section perpendicular to the axial direction. The permanent magnet electric motor according to any one of claims 1 to 4,
The length along the radial direction of the first magnet insertion portion and the length along the radial direction of the third magnet insertion portion are the same length Lmm, and along the radial direction of the second magnet insertion portion. A permanent magnet motor characterized in that the length Mmm satisfies [Mmm <Lmm / 3]. The permanent magnet motor according to any one of claims 1 to 5,
When viewed in a cross section perpendicular to the axial direction, the first magnet insertion portion and the third magnet insertion portion extend along an arc centered on the center point of the rotor. Magnet motor.

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