JPH11136889A - Permanent magnet motor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize an inductance of a stator winding and its change. SOLUTION: This permanent magnet motor is provided with a stator having a stator winding, and a rotor 21 constituted by building a permanent magnet 26 in a rotor iron core 22 consisting of laminated steel plates, whereas the permanent magnet 26 is constituted of an internal permanent magnet 24 stored in the rotor iron core 22a formed so as to extend axially inside the rotor iron core 22, and a cylindrical permanent magnet 25 fitted so as to cover the outer periphery of the rotor iron core 22. The internal permanent magnet 24 and the cylindrical permanent magnet 25 are constituted by integrally forming a bond magnet at the rotor iron core 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type motor provided with a rotor having a permanent magnet incorporated in a rotor core and a method of manufacturing the same.

[0002]

2. Description of the Related Art An example of this type of permanent magnet type motor is shown in FIG. As shown in FIG. 17, the permanent magnet motor 1 includes a stator 2 and a rotor 3 rotatably provided inside the stator 2. The stator 2 includes an annular stator core 4 made of a laminated steel plate, and a stator winding 6 inserted into a slot 5 provided in the stator core 4. As shown in FIG. 18, the stator winding 6 has three-phase (U-phase, V-phase, W-phase) windings 6u, 6v, 6
w.

The rotor 3 has a rotor core 7 made of a laminated steel plate, and four substantially arc-shaped cross sections housed and fixed in four housing portions 8 provided inside the rotor core 7. And a permanent magnet 9. Each of the above permanent magnets 9
The projection is disposed so as to face the axis. A rotating shaft 10 is fixedly penetrated to the shaft center of the rotor core 7. The permanent magnet motor 1 is configured to be energized and driven by a motor energizing device 11 shown in FIG.

[0004] The motor energizing device 11 includes a DC power supply 12.
And a control circuit 14 for controlling the inverter device 13. Inverter device 13
Is configured by connecting six transistors 13a in a three-phase bridge, and a freewheel diode 13b is connected to each transistor 13a. The control circuit 14 detects the induced voltages of the stator windings 6u, 6v, and 6w, and based on these detection signals, detects the stator windings 6u, 6v, and 6w.
A drive signal for energizing v and 6w by 120 degrees (electrical angle) in a predetermined order in two phases is generated, and each transistor 13a of the inverter device 13 is turned on / off by the drive signal. That is, the motor energizing device 1
Numeral 1 energizes and drives the permanent magnet type motor 1 in a so-called sensorless drive system.

[0005]

In the permanent magnet motor 1 having the above-described structure, the value of the inductance L of the stator winding 6 greatly changes depending on the relative position between the rotor 3 and the stator 2. The manner in which the inductance L changes according to the electrical angle is shown by a solid curve L1 in FIG. From this curve L1, a position at an electrical angle of 90 degrees, that is,
A position where the gap between the ends of the permanent magnet 9 of the rotor 3 faces the teeth 4a of the stator core 4 of the stator 2 (FIG. 20)
(See (a)) that the inductance L is maximized. This is because a magnetic path is formed at the above-mentioned position between the adjacent teeth via the stator core 4.

On the other hand, the rotor 3 moves 9
As shown in FIG. 20 (b), a position rotated by 0 degree,
When the intermediate portion of the permanent magnet 9 of the rotor 3 reaches a position facing the teeth 4a of the stator core 4 of the stator 2, the inductance L becomes minimum. This is because the magnetic path passing through the stator core 4 is hardly formed at the above position.

On the other hand, the permanent magnet type motor 1 is energized and driven by a sensorless drive system. In this case, the position of (the permanent magnet 9 of) the rotor 3 is detected based on the induced voltage of the stator winding 6. Specifically, when power is supplied to two of the three phases of the stator winding 6, the induced voltage of the remaining one phase that is not supplied is detected.

Here, the inductance L of the stator winding 6
Is extremely small, there is no current phase and no current flows through the winding 6 to be detected. For this reason, the waveform of the induced voltage is clear, and the position can be accurately detected. On the other hand, when the value of the inductance L of the stator winding 6 is large or its change is large, a phase-lagged current flows, so that the induced voltage is distorted. For this reason, there has been a problem that an error in position detection occurs and the current increases.

On the other hand, a countermeasure for providing a correction circuit for correcting an error in position detection can be considered. However, in the case of this configuration, the circuit configuration becomes complicated, the number of parts increases, and the manufacturing cost increases. The problem arises. Also, when the inductance L of the stator winding 6 increases, the impedance increases, the copper loss increases, and the output and efficiency may decrease.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a permanent magnet motor capable of reducing the value of the inductance of the stator winding and reducing the change, and a method of manufacturing the same.

[0011]

According to the present invention, there is provided a permanent magnet type motor comprising: a stator having a stator winding; and a rotor having a permanent magnet incorporated in a rotor core. The first permanent magnet is accommodated in an accommodating portion formed so as to extend in the axial direction inside the rotor core.
It is characterized by comprising a permanent magnet and a second permanent magnet provided so as to cover the outer peripheral portion of the rotor core.

According to the above configuration, the second permanent magnet is provided so as to cover the outer peripheral portion of the rotor core.
The inductance of the stator winding becomes constant irrespective of the relative position between the rotor and the stator, and the value of the inductance decreases. This makes it possible to accurately detect the position of the rotor based on the induced voltage of the stator winding. Further, in the case of the above configuration, since the value of the inductance L of the stator winding is small, the impedance becomes small,
It is possible to prevent the copper loss from being reduced and the output from lowering and the efficiency from lowering.

In the above configuration, the first permanent magnet accommodated in the accommodating portion inside the rotor core is formed to have a substantially arc-shaped cross section, and the convex side faces the axis of the rotor core. It is preferable to arrange them. Further, it is more preferable that the first permanent magnet and the second permanent magnet are configured by molding a bonded magnet.

According to another aspect of the present invention, there is provided a permanent magnet type motor comprising: a stator having a stator winding; and a rotor having a permanent magnet incorporated in a rotor core. And two or more steel plates having different outer diameters are alternately laminated one by one or a plurality of sheets, and the permanent magnet covers a portion of the outer peripheral portion of the rotor core having a smaller outer diameter. It is characterized in that it is constituted by a plurality of third permanent magnets provided as described above. In the case of this configuration, it is more preferable to include a fourth permanent magnet housed in a housing portion formed to extend in the axial direction inside the rotor core.

Further, in the permanent magnet type motor of each of the above structures, it is more preferable that the permanent magnet is formed by molding a bonded magnet and the magnetic orientation thereof is isotropic.

On the other hand, in the method of manufacturing the permanent magnet type motor of each of the above constitutions, a step of integrally forming a bond magnet on a rotor core, and a step of magnetizing the integrally formed bond magnet by a magnetizing device to form a permanent magnet. Forming a magnet.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to a 4-pole, 6-slot permanent magnet type motor will be described below with reference to FIGS. The stator of the permanent magnet type motor of this embodiment has the same configuration as the stator 2 of the prior art shown in FIG. 17, and only the rotor will be described here. Further, the motor energizing device for energizing and driving the permanent magnet type motor according to the present embodiment has the same configuration as the conventional motor energizing device 11 shown in FIG. 18, and the description is omitted here.

FIG. 1 is a perspective view of a rotor 21 of a permanent magnet type motor according to the present embodiment. As shown in FIG. 1, the rotor core 22 of the rotor 21 is, for example, a disk-shaped silicon steel plate 2.
3 (see FIG. 2). As shown in FIG. 2, each silicon steel plate 23 has a circular through-hole 23a formed at the center thereof and four substantially arc-shaped through-holes 23b formed therearound. These arc-shaped through holes 23b are formed so as to be convex toward the center side (inside). By laminating such silicon steel plates 23, a shaft hole 22a is formed in the center of the rotor core 22, and a storage portion 22b is formed around the shaft hole 22a.
Are formed.

A rotating shaft (not shown) is inserted and fixed in the shaft hole 22a of the rotor core 22. Also, four internal permanent magnets (first permanent magnets) each having a substantially arc-shaped cross section are provided in the four storage portions 22b of the rotor core 22.
24 are incorporated and fixed. Each internal permanent magnet 2
4 is disposed so that the convex side faces the axial center side. Further, each internal permanent magnet 24 is magnetized as shown in FIG.

The outer periphery of the rotor core 22 is provided so as to cover a cylindrical permanent magnet (second permanent magnet) 25. The cylindrical permanent magnet 25 is magnetized so as to correspond to the magnetic poles of the four internal permanent magnets 24. The cylindrical permanent magnet 25 and the four internal permanent magnets 24 constitute a permanent magnet 26 incorporated in the rotor 21.

Here, the internal permanent magnet 2 is attached to the rotor core 22.
The method of incorporating the permanent magnet 4 and the cylindrical permanent magnet 25 will be described. Each of the permanent magnets 24 and 25 is composed of, for example, a bonded magnet formed by combining a neodymium-based magnetic powder and a nylon resin, for example. The magnetic orientation of this bonded magnet is
It is configured to have isotropic properties. In this case, first, a step of integrally forming the bonded magnet on the rotor core 22 is executed.

Specifically, after a rotor having a rotating shaft inserted and fixed in the rotor core 22 is accommodated in a mold (not shown), the mold is filled with a fluid material before the bond magnet is cured. Let it cure. In this case, only the rotor core 22 before the rotation shaft is inserted and fixed is accommodated in a molding die, and a bonded magnet is integrally formed. After the integrally formed or magnetized, the rotation core is attached to the rotor core 22. May be configured to be inserted and fixed. Thus, the inside of the storage portion 22b of the rotor core 22 is filled with the bonded magnet portion corresponding to the internal permanent magnet 24, and is integrally formed. At the same time, it is integrally formed on the outer peripheral portion of the rotor core 22 so as to cover the bonded magnet portion corresponding to the cylindrical permanent magnet 25.

Subsequently, a step of magnetizing each of the bonded magnet portions integrally formed on the rotor core 22 by a magnetizing device is executed. Here, as shown in FIG.
A rotor core 22 integrally formed with a bonded magnet is set on the substrate, and the bonded magnet, that is, the portion corresponding to the internal permanent magnet 24 and the portion corresponding to the cylindrical permanent magnet 25 are simultaneously magnetized. Thereby, the permanent magnet 24 and the disk-shaped permanent magnet 2
The magnet 5 is magnetized as shown in FIG. 1, and the operation of incorporating the permanent magnet 24 and the disk-shaped permanent magnet 25 into (the rotor core 22 of) the rotor 21 is completed. The magnetizing device 27 includes a magnetizing yoke 28 and a magnetizing winding 29.

According to this embodiment having such a configuration, since the cylindrical permanent magnet 25 is provided so as to cover the outer peripheral portion of the rotor core 22, the inductance L of the stator winding is The value is constant regardless of the relative position of the stator 21 and the stator, and the value of the inductance L is reduced. The change in the value of the inductance L of the stator winding of this embodiment is shown by a solid line L2 in FIG. In FIG. 4, a two-dot chain line L1 indicates a change in the inductance L of the conventional configuration (see FIG. 19).

As is apparent from FIG. 4, in the above embodiment, the inductance L of the stator winding becomes constant irrespective of the electrical angle of the rotor 21 and its value decreases. For this reason, the waveform of the induced voltage generated in the stator winding becomes clear, and the position of the rotor 21 can be accurately detected. Accordingly, since the timing of applying a current of 120 degrees (electrical angle) to the stator winding is an appropriate timing, the phases of the drive voltage and the induced voltage are matched, and the ripple of the current is reduced and the torque unevenness is reduced. . In the case of the above embodiment, since no correction circuit is required, the circuit configuration is simplified, the number of components is reduced, and the manufacturing cost can be reduced.

Further, in the case of the above embodiment, since the value of the inductance L of the stator winding is small, the impedance is reduced, the copper loss is reduced, and the reduction in output and efficiency can be prevented as much as possible.

Further, in the above embodiment, the internal permanent magnet 24 stored in the storage portion 22b inside the rotor core 22 is used.
Are formed in a substantially arc-shaped cross section, and are arranged such that the projections face the axis of the rotor core 22. According to this configuration, as shown in FIG.
7, when the internal permanent magnet 24 and the cylindrical permanent magnet 25 are magnetized, since the internal permanent magnet 24 has a substantially inverted arc shape in cross section, the magnetizing magnetic field (shown by an annular solid line in FIG. 3). ) Are distributed so as to pass through the radial direction of the internal permanent magnet 24 with respect to both the intermediate portion and the end portion of the internal permanent magnet 24. That is, the magnetization magnetic field is distributed in a direction in which the magnetization is easy. Therefore, the internal permanent magnet 24 can be satisfactorily magnetized to the end.

A case where only the cylindrical permanent magnet is provided on the outer peripheral portion of the rotor core and magnetized by the magnetizing device 27 will be described with reference to FIG. In the case of this configuration, as shown in FIG. 21, as for the central portion of the pole of the cylindrical permanent magnet 31 provided on the outer peripheral portion of the rotor core 30, the magnetization magnetic field is in the radial direction of the cylindrical permanent magnet 31. Distributed to pass through. However, for the end portions of the poles of the cylindrical permanent magnet 31, the magnetizing magnetic field is
Are distributed so as to pass in the circumferential direction. For this reason,
The magnetic flux component from the end portion of the pole of the magnetized cylindrical permanent magnet 31 toward the gap (gap between the rotor and the stator), that is, a problem that the effective magnetic flux is reduced occurs. Incidentally, there is a method in which the cylindrical permanent magnet 31 is magnetized singly and then attached to the rotor core. However, in this case, work such as post-processing is increased, so that manufacturing workability is increased. The problem occurs that is worse.

On the other hand, in the above embodiment, the rotor 2
Since the permanent magnet 26 incorporated in 1 is composed of the internal permanent magnet 24 and the cylindrical permanent magnet 25 having a substantially arc-shaped cross section, as described above, the internal permanent magnet 24 is entirely formed from the central portion to the end. Good magnetization can be achieved, and the effective magnetic flux increases. Further, in the above embodiment, since the magnetic orientation of each of the permanent magnets 24 and 25 (that is, the bond magnet) is configured to be isotropic, it is easy to control the direction of the magnetic flux when magnetizing.

In the above embodiment, the internal permanent magnet 24 and the cylindrical permanent magnet 25 are formed integrally with the rotor core 22 (so-called insert molding) by using a molding die. It was configured to be incorporated into. According to this configuration, it is easy to ensure the dimensional accuracy of the cylindrical permanent magnet 25, and as a result, the gap can be reduced.

In the above-described embodiment, the internal permanent magnet 24 is formed to have a substantially arc-shaped cross section. However, the internal permanent magnet 24 has a cross-sectional shape like the second to sixth embodiments of the present invention shown in FIGS. The magnets 32 to 36 may be configured. Further, as in the seventh embodiment of the present invention shown in FIG. 10, the internal permanent magnet 37 having a substantially arc-shaped cross section may be arranged in a radially double manner. In this case, the internal permanent magnets may be configured so as to be multiplexed three or more times. Also, in the second to sixth embodiments of the present invention shown in FIGS.
You may comprise so that internal permanent magnets may be arrange | positioned multiple in a radial direction.

FIGS. 11 and 12 show an eighth embodiment of the present invention, and the points different from the first embodiment will be described. In the eighth embodiment, the rotor iron core 38 is configured by alternately stacking two or more circular steel plates 39 and 40 having different outer diameters one by one or a plurality of them. Specifically, the rotor core 38 is configured by alternately stacking an iron core portion in which a predetermined number of steel plates 39 having small outer diameters are stacked and an iron core portion formed of one steel plate 40 having a large outer diameter. ing.

Then, a plurality of short cylindrical permanent magnets (third permanent magnets) 41 are provided so as to cover a portion having a small outer diameter of the outer peripheral portion of the rotor core 38.
In the case of this configuration, a plurality of short cylindrical permanent magnets 41 constitute a permanent magnet 42 to be incorporated into the rotor 21. still,
In this embodiment, no internal permanent magnet is provided inside the rotor core 38. In this embodiment,
A plurality of short cylindrical permanent magnets 41 are provided on the outer peripheral portion of the rotor core 38.
In this case, the bond magnet is formed integrally with the rotor core 38 by using a mold in substantially the same manner as in the first embodiment. The bond magnet used at this time is, for example, a bond magnet formed by combining neodymium-based magnetic powder and nylon resin, for example, as in the first embodiment.

The configuration of the eighth embodiment other than the above is the same as the configuration of the first embodiment. Therefore, in the eighth embodiment, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the eighth embodiment, the outer peripheral portion of the rotor core 38 is configured to be covered with a plurality of short cylindrical permanent magnets 41 that are electrically divided in the axial direction. The eddy current loss generated on the surface of the short cylindrical permanent magnet 41 due to the alternating magnetic field generated by the slave winding can be reduced (see the small arrow in FIG. 12).

Here, in the case of a configuration in which a permanent magnet made of a neodymium-based bonded magnet is incorporated in a rotor, there is a situation that eddy current loss generated on the surface of the permanent magnet becomes a considerable problem. Specifically, as shown in FIG. 22, the outer peripheral portion of the rotor core 43 is covered with a cylindrical permanent magnet 44,
When the cylindrical permanent magnet 44 is formed of a neodymium-based bonded magnet, a considerably large eddy current loss occurs on the surface of the cylindrical permanent magnet 44 due to the alternating magnetic field generated by the stator winding (see a large arrow in FIG. 22). The eddy current loss causes a problem that the cylindrical permanent magnet 44 generates heat and expands thermally. In this case, since the size of the gap changes, there is a problem that torque unevenness occurs, and vibration and noise increase. Also,
Since a large eddy current loss occurs, the current flowing through the stator winding increases, and there is a problem that the driving efficiency is reduced.

On the other hand, according to the above embodiment, the outer peripheral portion of the rotor core 38 is covered with a plurality of short cylindrical permanent magnets 41 electrically divided in the axial direction.
As shown in (1), the eddy current loss generated on the surface of each short cylindrical permanent magnet 41 is significantly reduced. For this reason, heat generation of each short cylindrical permanent magnet 41 is reduced, and thermal expansion is reduced. Also, since the current flowing through the stator winding does not increase,
Driving efficiency can be made sufficiently high.

FIG. 13 shows a ninth embodiment of the present invention, and the differences from the eighth embodiment will be described. still,
The same parts as those in the eighth embodiment are denoted by the same reference numerals. In the ninth embodiment, as shown in FIG. 13, a storage part 38b having the same configuration as the storage part 22b of the first embodiment is provided inside the rotor core 38, and the first part is provided in the storage part 38b. An internal permanent magnet (fourth permanent magnet) 25 having the same configuration as that of the embodiment is housed and fixed.

According to the ninth embodiment, in addition to the operation and effect of the eighth embodiment, the internal permanent magnet 25 having a substantially arc-shaped cross section is incorporated inside the rotor core 38.
High torque and high efficiency can be realized.

FIGS. 14 and 15 show a tenth embodiment of the present invention, and the points different from the first embodiment will be described. The same parts as those of the first embodiment are denoted by the same reference numerals. In the tenth embodiment, as shown in FIG. 14, a permanent magnet 47 obtained by integrating an internal permanent magnet 45 having a substantially arc-shaped cross section and a cylindrical permanent magnet 46 is used as a rotor core 48.
It is configured to be incorporated into. In this configuration,
The rotor core 48 has a centrally located central portion 48a.
And four outer peripheral portions 48b arranged outside thereof. Central portion 48a and outer peripheral portion 48b
Are each composed of a laminated iron core. The central portion 48a and the outer peripheral portion 48b are integrally formed by the permanent magnet 47 so that the rotor core 48 and the rotor 21 are formed.

Here, the rotor core 48 (center portion 4)
A description will be given of a manufacturing operation for integrally molding the permanent magnet 47 and the outer portion 8a and the outer peripheral portion 48b). In this case, first, the separated central portion 48a and the outer peripheral portion 48b constituting the rotor core 48 are placed in a molding die (not shown), and these components are positioned by positioning pins or the like. Thus, cavities for the four internal permanent magnets 45 and the cylindrical permanent magnets 46 (that is, the permanent magnets 47) are formed in the mold.

Subsequently, the mold is filled with a fluid material before curing of the bonded magnet and cured. Thus, the rotor core 48, the internal permanent magnet 45, and the cylindrical permanent magnet 46
(Bonded magnet). And after this,
As shown in FIG. 15, the rotor core 48 integrally formed with the bond magnet is set in the magnetizing device 27 and magnetized.

The configuration of the tenth embodiment other than the above is the same as the configuration of the first embodiment. Therefore, in the tenth embodiment, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the tenth embodiment, the internal permanent magnet 45 and the cylindrical permanent magnet 46 are formed by forming a bonded magnet and are integrated so that the inductance L of the stator winding is reduced. It can be even smaller.

FIG. 16 shows an eleventh embodiment of the present invention, and different points from the first embodiment will be described.
The same parts as those of the first embodiment are denoted by the same reference numerals. In the eleventh embodiment, as shown in FIG. 16, storage portions 49 a to 49 c are provided, for example, three times in the radial direction inside the stator core 22. And each of the storage sections 49a to 49
The internal permanent magnets 50a, 50b, and 50c are housed and fixed in c. In this case, the inside of the storage portions 49a to 49c,
A space is appropriately formed between the internal permanent magnets 50a, 50b, and 50c. In particular,
The space between the storage portion 49a and the internal permanent magnet 50a is fitted without a gap, and the space between the storage portion 49b and the internal permanent magnet 50b, and between the storage portion 49c and the internal permanent magnet 50c, respectively. Are formed.

According to this configuration, the internal permanent magnets 50a,
By adjusting the shapes of 50b and 50c, the magnetic flux distribution in the gap can be easily controlled. For example, it is easily possible to configure the gap such that the magnetic flux distribution of the gap has a sine wave shape. In the above configuration, when the internal permanent magnets 50a, 50b, and 50c are stored in the storage portions 49a to 49c of the rotor core 22, the non-magnetized internal permanent magnets 5 previously formed by the bond magnets are used.
It is preferable to insert and fix Oa, 50b, and 50c in storage parts 49a-49c. Further, it is preferable that the cylindrical permanent magnet 25 on the outer peripheral portion of the rotor core 22 is formed by integrally molding a bonded magnet with the rotor core 22 in the same manner as in the first embodiment. Then, the internal permanent magnets 50a, 50
It is preferable that the magnets b and 50c and the cylindrical permanent magnet 25 are simultaneously magnetized by the magnetizing device 27.

The configuration of the eleventh embodiment other than the above is the same as the configuration of the first embodiment. Therefore, also in the eleventh embodiment, substantially the same operation and effect as those of the first embodiment can be obtained. In particular, in the eleventh embodiment, the cogging torque can be minimized by adjusting the shape of the internal permanent magnets 50a, 50b, 50c so that the magnetic flux distribution in the gap has a sinusoidal shape.

In the above-described embodiment, the triple storage portion 49a is provided.
To 49c, but is not limited to this.
A storage unit having a weight equal to or greater than the weight may be provided, or a double storage unit may be provided. In the above embodiment, the cylindrical permanent magnet may be formed in advance, and the formed non-magnetized cylindrical permanent magnet may be fitted and attached to the outer peripheral portion of the rotor core 22. good. Further, the internal permanent magnet 50 after being magnetized
a, 50b, and 50c are stored in the storage portions 49a to 49c of the rotor core 22.
The cylindrical permanent magnet formed and magnetized may be fitted into the outer peripheral portion of the rotor core 22 while being inserted and fitted into the inside of the core 49c.

In each of the above embodiments, the internal permanent magnet and the disk-shaped permanent magnet are constituted by the neodymium-based magnetic powder and the bonded magnet using the nylon resin. The internal permanent magnet and the disk-shaped permanent magnet may be constituted by the used bond magnet.

[0048]

According to the present invention, as is apparent from the above description, the permanent magnet to be incorporated in the rotor core is accommodated in the first storage portion formed in the rotor core so as to extend in the axial direction. Since it is composed of the permanent magnet and the second permanent magnet provided so as to cover the outer periphery of the rotor core, the value of the inductance of the stator winding can be reduced, and its change can be reduced, and thus the stator winding can be reduced. When the position of the rotor is detected based on the induced voltage of the wire, the position detection can be accurately performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rotor showing a first embodiment of the present invention.

FIG. 2 is a top view of a silicon steel sheet.

FIG. 3 is a diagram illustrating an operation when magnetized by a magnetizing device;

FIG. 4 is a diagram showing a change in inductance of a stator winding;

FIG. 5 is a top view of a rotor showing a second embodiment of the present invention.

FIG. 6 is a view corresponding to FIG. 5, showing a third embodiment of the present invention.

FIG. 7 is a view corresponding to FIG. 5, showing a fourth embodiment of the present invention.

FIG. 8 is a view corresponding to FIG. 5, showing a fifth embodiment of the present invention.

FIG. 9 is a view corresponding to FIG. 5, showing a sixth embodiment of the present invention.

FIG. 10 is a view corresponding to FIG. 5, showing a seventh embodiment of the present invention;

FIG. 11 is a cutaway perspective view of a rotor showing an eighth embodiment of the present invention.

FIG. 12 is a diagram corresponding to FIG. 11 for explaining operation.

FIG. 13 is a view corresponding to FIG. 11, showing a ninth embodiment of the present invention;

FIG. 14 is a view corresponding to FIG. 5, showing a tenth embodiment of the present invention.

FIG. 15 is a diagram corresponding to FIG. 3;

FIG. 16 is a view corresponding to FIG. 5, showing an eleventh embodiment of the present invention.

FIG. 17 is a sectional view of a permanent magnet motor showing a conventional configuration.

FIG. 18 is an electrical configuration diagram of a permanent magnet motor and a motor energizing device.

FIG. 19 is a diagram corresponding to FIG. 4;

20A is a diagram illustrating a positional relationship between a rotor having a maximum inductance and a stator, and FIG. 20B is a diagram illustrating a positional relationship between a rotor having a minimum inductance and a stator.

FIG. 21 is a diagram corresponding to FIG. 3;

FIG. 22 is a perspective view of a rotor.

[Explanation of symbols]

21 is a rotor, 22 is a rotor core, 22b is a storage part, 2
4 is an internal permanent magnet, 25 is a cylindrical permanent magnet, 26 is a permanent magnet, 27 is a magnetizing device, 30 is a rotor core, 31 is a cylindrical permanent magnet, 32 to 37 are internal permanent magnets, and 38 is a rotor core. , 39 and 40 are steel plates, 41 is a short cylindrical permanent magnet, 4
2 is a permanent magnet, 43 is a rotor core, 44 is a cylindrical permanent magnet, 45 is an internal permanent magnet, 46 is a cylindrical permanent magnet, 47
Denotes a permanent magnet, 48 denotes a rotor core, 49a to 49c denote housing portions, and 50a, 50b, 50c denote internal permanent magnets.

Claims (7)

[Claims] 1. A permanent magnet type motor comprising: a stator having a stator winding; and a rotor having a rotor core with a permanent magnet incorporated therein. A first permanent magnet housed in a housing portion formed to extend in the axial direction therein, and a second permanent magnet provided so as to cover an outer peripheral portion of the rotor core. Permanent magnet type motor. 2. The permanent magnet according to claim 1, wherein the first permanent magnet is formed to have a substantially arc-shaped cross section, and is arranged such that a convex side thereof faces an axial center side of the rotor core. 2. The permanent magnet type motor according to 1. 3. The permanent magnet motor according to claim 1, wherein the first permanent magnet and the second permanent magnet are formed by molding a bonded magnet. 4. A permanent magnet motor comprising: a stator having a stator winding; and a rotor having a rotor core with a permanent magnet incorporated therein, wherein the rotor core has an outer diameter dimension. Two different types of steel sheets
The permanent magnet is constituted by a plurality of third permanent magnets provided so as to cover a portion having a small outer diameter of an outer peripheral portion of the rotor core. A permanent magnet type motor characterized in that: 5. The permanent magnet type motor according to claim 4, further comprising a fourth permanent magnet housed in a housing portion formed in the rotor core so as to extend in the axial direction. 6. The permanent magnet according to claim 1, wherein the permanent magnet is formed by molding a bonded magnet, and has a magnetic orientation that is isotropic. Shaped motor. 7. A method for manufacturing a permanent magnet type motor according to claim 1, wherein a bonded magnet is integrally formed on a rotor core, and the integrated bonded magnet is mounted on a magnetizing device. Forming a permanent magnet by magnetizing the permanent magnet type motor.