WO2017014212A1 - Motor - Google Patents

Abstract

A motor includes a stator having windings and a rotor which rotates upon being subjected to a rotating magnetic field produced by a driving current being fed to the windings. The rotor includes a rotor core and a first magnet magnetic pole, a second magnet magnetic pole, and a protrusion provided next to each other in the circumferential direction. For the first magnet magnetic pole, a permanent magnet provided to the rotor core is used. For the second magnet magnetic pole, a permanent magnet provided to the rotor core is used, and the second magnet magnetic pole has an opposite polarity to the first magnet magnetic pole. The protrusion is formed so as to project in the radial direction in the rotor core. The windings include a first winding and a second winding. The first winding and the second winding are excited at the same timing by a driving current, and are serially connected. The motor is configured so that the protrusion faces the second winding at the rotor rotation position at which the first magnet magnetic pole or the second magnet magnetic pole faces the first winding.

Description

motor

The present invention relates to a motor.

Conventionally, a permanent magnet motor such as a brushless motor includes, for example, a stator in which a winding is wound around a stator core and a rotor having a permanent magnet facing the stator as a magnetic pole, as shown in Patent Document 1, for example. The rotor rotates by receiving a rotating magnetic field generated by supplying a drive current to the winding of the stator.

JP 2014-135852 A

In the permanent magnet motor as described above, the higher the rotor is driven, the larger the induced voltage generated in the stator winding due to the increase of the interlinkage magnetic flux by the permanent magnet of the rotor, and this induced voltage decreases the motor output. This hinders high motor rotation.

An object of the present invention is to provide a motor capable of achieving high rotation.

To achieve the above object, a motor according to an aspect of the present invention includes a stator having windings and a rotor that rotates by receiving a rotating magnetic field generated by supplying a driving current to the windings. The rotor includes a rotor core and a first magnet magnetic pole, a second magnet magnetic pole, and a protrusion that are arranged in parallel in the circumferential direction. The first magnet magnetic pole uses a permanent magnet provided on the rotor core. The second magnet magnetic pole uses a permanent magnet provided on the rotor core, and has a different polarity with respect to the first magnet magnetic pole. The protrusion is formed to protrude in the radial direction in the rotor core. The winding includes a first winding and a second winding. The first winding and the second winding are excited at the same timing by the drive current and are connected in series. The motor is configured such that the first magnet magnetic pole or the second magnet magnetic pole is at a rotational position of the rotor facing the first winding, and the protrusion is opposed to the second winding.

It is a top view of the motor concerning the embodiment of the present invention. It is an electric circuit diagram which shows the connection aspect of the coil | winding of FIG. It is a top view for demonstrating the arrangement pattern of the magnetic pole in the rotor of FIG. 1, and a protrusion. It is a top view for demonstrating the setting pattern of the magnet magnetic pole in the rotor of FIG. 1, and the opening angle of a protrusion. It is a top view of the rotor of another example. It is an electric circuit diagram which shows the connection aspect of the coil | winding in another example. It is a top view of the motor of another example. It is a top view for demonstrating the arrangement pattern of the magnet magnetic pole and protrusion in the rotor of the said another example. It is a top view for demonstrating the setting pattern of the open angle of the magnet magnetic pole and protrusion in the rotor of the said another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example. It is a top view of the rotor of another example.

Hereinafter, an embodiment of the motor will be described.
As shown in FIG. 1, the motor 10 of the present embodiment is configured as a brushless motor, and a rotor 21 is arranged inside an annular stator 11.

[Structure of stator]
The stator 11 includes a stator core 12 and a winding 13 wound around the stator core 12. The stator core 12 is formed of a magnetic metal in a substantially annular shape, and has twelve teeth 12a extending radially inward at equal angular intervals in the circumferential direction.

Twelve windings 13 having the same number as the teeth 12a are provided, and each tooth 12a is wound in the same direction by concentrated winding. That is, twelve windings 13 are provided at equal intervals in the circumferential direction (30 ° intervals). The windings 13 are classified into three phases according to the three-phase driving currents (U phase, V phase, W phase) supplied, and U1, V1, W1, U2 in order counterclockwise in FIG. , V2, W2, U3, V3, W3, U4, V4, W4.

Referring to each phase, the U-phase windings U1 to U4 are arranged at equal intervals in the circumferential direction (90 ° intervals). Similarly, the V-phase windings V1 to V4 are arranged at equal circumferential intervals (90 ° intervals). Similarly, the W-phase windings W1 to W4 are arranged at equal intervals in the circumferential direction (90 ° intervals).

Further, as shown in FIG. 2, the windings 13 are connected in series for each phase. That is, the U-phase windings U1 to U4, the V-phase windings V1 to V4, and the W-phase windings W1 to W4 each constitute a series circuit. In this embodiment, a series circuit of U-phase windings U1 to U4, a series circuit of V-phase windings V1 to V4, and a series circuit of W-phase windings W1 to W4 are star-connected.

[Configuration of rotor]
As shown in FIG. 1, the rotor core 22 of the rotor 21 is formed of a magnetic metal in a substantially disk shape, and a rotating shaft 23 is fixed at the center. On the outer periphery of the rotor core 22, two magnetic pole pairs P composed of an N-pole magnet magnetic pole Mn and an S-pole magnet magnetic pole Ms adjacent to each other in the circumferential direction, and four which are integrally formed with the rotor core 22 and protrude radially outward. The protrusions 24a, 24b, 24c, and 24d are juxtaposed in the circumferential direction. That is, the rotor 21 is provided with the same number of magnet magnetic poles Mn, Ms and protrusions 24a to 24d. The magnet magnetic poles Mn and Ms function as a first magnet magnetic pole and a second magnet magnetic pole, respectively.

The magnetic pole pair P is provided at a position opposite to each other at 180 ° in the circumferential direction. Between the circumferential directions of the magnetic pole pair P, a pair of protrusions 24a and 24b adjacent in the circumferential direction and a pair of adjacent in the circumferential direction are provided. Protrusions 24c and 24d are provided. Specifically, on the outer peripheral portion of the rotor 21, in order in the clockwise direction, the S magnetic pole Ms, the N magnetic pole Mn, the protrusion 24 a, the protrusion 24 b, the S magnetic pole Ms, N pole. Magnet magnetic pole Mn, protrusion 24c, and protrusion 24d.

The N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms each have a permanent magnet 25 fixed to the outer peripheral surface of the rotor core 22. That is, the rotor 21 has a surface magnet type structure (SPM structure) in which four permanent magnets 25 are fixed to the outer peripheral surface of the rotor core 22.

The permanent magnets 25 have the same shape, and the pair of permanent magnets 25 in the magnetic pole pair P are arranged adjacent to each other in the circumferential direction. In addition, the outer peripheral surface (radially outer surface) that is the surface facing each of the permanent magnets 25 in the permanent magnet 25 has an arc shape with the axis L as the center when viewed from the direction of the axis L of the rotating shaft 23. In addition, the outer peripheral surface (radial outer surface) that is the surface facing the stator 11 in each of the protrusions 24a to 24d has an arc shape that is located on the same circle as the outer peripheral surface of each permanent magnet 25 when viewed from the axis L direction. Is formed.

Each permanent magnet 25 is formed so that the magnetic orientation faces the radial direction. More specifically, the permanent magnet 25 of the N-pole magnet magnetic pole Mn is magnetized in the radial direction so that the magnetic pole appearing on the outer peripheral side becomes the N-pole, and the permanent magnet 25 of the S-pole magnet magnetic pole Ms has the magnetic pole appearing on the outer peripheral side. It is magnetized in the radial direction so as to be the south pole. Each permanent magnet 25 is, for example, an anisotropic sintered magnet, and includes, for example, a neodymium magnet, a samarium cobalt (SmCo) magnet, an SmFeN-based magnet, a ferrite magnet, an alnico magnet, or the like. Moreover, each permanent magnet 25 is arrange | positioned so that the thing of the same pole may oppose 180 degrees in the circumferential direction. That is, the N-pole magnet magnetic poles Mn are arranged at positions opposite to each other by 180 °. Similarly, the S-pole magnet magnetic poles Ms are arranged at positions opposed to each other by 180 °.

Next, the operation of this embodiment will be described.
A three-phase drive current (AC) having a phase difference of 120 ° is supplied from a drive circuit (not shown) to the U-phase windings U1 to U4, the V-phase windings V1 to V4, and the W-phase windings W1 to W4, respectively. Then, the windings U1 to W4 are excited at the same timing for each phase to generate a rotating magnetic field in the stator 11, and the rotor 21 rotates based on the rotating magnetic field. At this time, magnet torque is generated in the rotor 21 by the action of the rotating magnetic field of the stator 11 and the magnet magnetic poles Mn and Ms, and reluctance torque is applied to the rotor 21 by the action of the rotating magnetic field of the stator 11 and the protrusions 24a to 24d of the rotor core 22. Arise.

Further, at this time, the magnetic poles formed on the stator 11 by supplying the three-phase driving currents have the same polarity for the windings U1 to W4 of the respective phases. Note that the number of magnetic poles (the number of magnet magnetic poles Mn and Ms) of the rotor 21 of this embodiment is four, but the number of poles of the rotor 21 is set to the magnet magnetic poles Mn and Ms in the windings U1 to W4 of each phase. The drive current set is assumed to be twice the number of (8 poles in this embodiment).

When the rotor 21 rotates at high speed, field weakening control for supplying a field weakening current (d-axis current) to the winding 13 is executed. When the rotor 21 rotates at high speed (field weakening control), for example, as shown in FIG. 1, when the N-pole magnet magnetic pole Mn is opposed to the U-phase windings U1, U3 in the radial direction, the protrusions 24b, 24d Are opposed to the U-phase windings U2 and U4 in the radial direction, respectively.

At this time, a field weakening current is supplied to each of the U-phase windings U1 to U4. However, in the U-phase windings U1 and U3, a magnetic flux (radially outward) generated by the opposing N-pole magnet magnetic poles Mn. Magnetic flux) exceeds the interlinkage magnetic flux (interlinkage magnetic flux inward in the radial direction) caused by the field weakening current, and the interlinkage magnetic flux φx that passes outward in the radial direction is generated in the U-phase windings U1 and U3.

On the other hand, in the U-phase windings U2 and U4, the portions of the rotor 21 facing each other are not the magnet magnetic pole Mn but the protrusions 24b and 24d of the rotor core 22, so that the interlinkage magnetic flux φy due to the field weakening current does not disappear. The interlinkage magnetic flux φy passes through the phase windings U2 and U4 inward in the radial direction. In this way, the protrusions 24b and 24d of the rotor core 22 facing the U-phase windings U2 and U4 are allowed to generate the linkage flux φy due to the field weakening current. The magnetic flux Mn generates an interlinkage magnetic flux φy having a phase opposite to that of the interlinkage magnetic flux φx generated in the U-phase windings U1 and U3.

Then, an induced voltage is generated by the interlinkage magnetic fluxes φx and φy in each of the U-phase windings U1 to U4. At this time, since the interlinkage magnetic fluxes φx and φy are in opposite phases, the induced voltage generated in the U-phase windings U2 and U4 by the interlinkage magnetic flux φy is induced in the U-phase windings U1 and U3 by the interlinkage magnetic flux φx. Since the polarity is opposite to the voltage (reverse phase), the combined induced voltage obtained by combining the induced voltages of the U-phase windings U1 to U4 is effectively reduced.

It should be noted that the above action also occurs in the winding facing the S magnetic pole Ms. That is, when the S-pole magnet magnetic pole Ms faces, for example, the U-phase windings U1, U3, the protrusions 24a, 24c of the rotor core 22 face the U-phase windings U2, U4, respectively. The induced voltage generated in U3 and the induced voltage generated in U-phase windings U2 and U4 are in opposite phases, and the combined induced voltage in each U-phase winding U1 to U4 is effectively reduced.

In the above description, the combined induced voltage of the U-phase windings U1 to U4 has been described as an example. Similarly, the protrusions 24a to 24d of the rotor core 22 are also applied to the V-phase windings V1 to V4 and the W-phase windings W1 to W4. This causes a decrease in the synthesis induced voltage.

[Arrangement of rotor magnetic poles and protrusions]
As shown in FIG. 3, the total number of magnet magnetic poles Mn and Ms is n, and 2n reference lines extending in the radial direction from the rotation axis of the rotor 21 (axis L of the rotation shaft 23) are equiangularly spaced in the circumferential direction. Set to. In the present embodiment, since the total number of magnet magnetic poles Mn and Ms is 4, eight reference lines X1 to X8 are set at equal intervals of 45 ° in the clockwise direction.

The magnet magnetic poles Mn and Ms are arranged so that their circumferential centers coincide with any of the eight reference lines X1 to X8.
Specifically, the pair of N-pole magnet magnetic poles Mn are arranged so that their circumferential centers coincide with the reference lines X4 and X8. That is, the pair of N-pole magnet magnetic poles Mn are disposed at positions that oppose each other at 180 ° in the circumferential direction.

Also, the pair of S-pole magnet magnetic poles Ms are arranged so that their circumferential centers coincide with the reference lines X3 and X7. That is, the pair of S-pole magnet magnetic poles Ms are disposed at positions that oppose each other at 180 ° in the circumferential direction. Further, the magnet magnetic poles Mn and Ms adjacent to each other in the magnetic pole pair P have an interval (open angle) between their circumferential centers set to 45 °.

On the other hand, the protrusions 24a to 24d are arranged such that their circumferential centers C1 to C4 are deviated from any of the reference lines X1 to X8. Hereinafter, several arrangement patterns of the protrusions 24a to 24d will be exemplified.

In the following, the deviation angle of the circumferential center C1 of the protrusion 24a with respect to the reference line X1 is θa, the deviation angle of the circumferential center C2 of the protrusion 24b with respect to the reference line X2 is θb, and the circumference of the protrusion 24c with respect to the reference line X5. Description will be made assuming that the deviation angle of the direction center C3 is θc, the deviation angle of the circumferential center C4 of the protrusion 24d with respect to the reference line X6 is θd, and the deviation angle in the clockwise direction is a positive value.

(Arrangement pattern 1)
θa <0 °, θb> 0 °
θc = θa
θd = θb
(Arrangement pattern 2)
θa> 0 °, θb <0 °
θc = θa
θd = θb
(Arrangement pattern 3)
θa <0 °, θb <0 °
θc = θa
θd = θb
(Arrangement pattern 4)
θa> 0 °, θb> 0 °
θc = θa
θd = θb
In any of the above arrangement patterns 1 to 4, θc = θa and θd = θb are set. However, the present invention is not limited to this, and may be set as θc ≠ θa and θb ≠ θd. In the arrangement patterns 1 to 4, θa to θd ≠ 0 °, that is, any of the protrusions 24a to 24d is configured to be shifted with respect to the reference lines X1, X2, X5, and X6. As long as at least one of ˜24d is displaced from the reference line, the remaining protrusions may be arranged so that the center in the circumferential direction coincides with the reference line.

Further, it is desirable that gaps are formed between the protrusions 24a and 24b ( protrusions 24c and 24d) adjacent in the circumferential direction and between the magnetic poles Mn and Ms adjacent to the protrusions 24a to 24d. .

[Opening angle of rotor magnetic poles and protrusions]
Next, the open angle θn of the outer peripheral surface 26 (radially outer surface) of the N-pole magnet magnetic pole Mn (N-pole permanent magnet 25), and the outer peripheral surface 27 of the S-pole magnet magnetic pole Ms (S-pole permanent magnet 25). The setting of the opening angle θs of the (radial outer surface) and the opening angles θ1 to θ4 of the outer peripheral surface 28 (radial outer surface) of the protrusions 24a to 24d will be described with reference to FIG. The open angle is an angle from one end to the other end in the circumferential direction of the object. Each of the outer peripheral surfaces 26 to 28 functions as an opposing surface.

The open angles θn and θs of the magnetic poles Mn and Ms are set to be equal to each other, and the open angles θ1 to θ4 of the protrusions 24a to 24d are set to be smaller than the open angles θn and θs. In the following, several setting patterns for the open angles θ1 to θ4 of the protrusions 24a to 24d will be exemplified.

(Open angle setting pattern 1)
θn = θs = α
θ1 = θ2 = θ3 = θ4 = β
β <α
(Open angle setting pattern 2)
θn = θs = α
θ1 = θ3 = β
θ2 = θ4 = γ
β ≠ γ
β, γ <α
(Open angle setting pattern 3)
θ1 = θ2 = θ3 = θ4 = α
α <θs <θn
In any of the above setting patterns 1 to 3, although θ1 = θ3 and θ2 = θ4 are set, the present invention is not limited to this, and θ1 ≠ θ3 and θ2 ≠ θ4 may be set.

In the configuration shown in FIG. 4, the centers of the protrusions 24a to 24d are arranged so as to coincide with the reference lines X1, X2, X5, and X6, respectively, but not limited to this, the arrangement patterns 1 to 4 described above are arranged. It is also possible to adopt a configuration in which any one of the above opening angle setting patterns 1 to 3 is combined.

Next, characteristic advantages of this embodiment will be described.
(1) The windings 13 of the stator 11 are composed of four U-phase windings U1 to U4, V-phase windings V1 to V4, and W-phase windings W1 to W4, respectively, corresponding to the supplied three-phase driving current. Thus, the four windings of each phase are connected in series. That is, the winding 13 of the stator 11 includes at least two windings (first winding and second winding) connected in series in each phase. Then, the magnetic pole Mn (or the magnetic pole Ms) is, for example, a rotational position facing the U-phase windings U1 and U3, and the protrusions 24b and 24d (or the protrusions 24a and 24c) are respectively connected to the U-phase windings U2 and U4. Configured to face each other.

According to this configuration, the protrusions 24a to 24d, which are part of the rotor core 23, operate without disturbing the generation of the interlinkage magnetic flux due to the field weakening current (d-axis current) in the second winding. The induced voltage generated by the linkage flux φy due to the field weakening current in the winding 13 facing the protrusions 24a to 24d is opposite to the induced voltage generated in the winding 13 facing the magnet magnetic pole Mn (or the magnet magnetic pole Ms). Polarity (reverse phase). Thereby, the synthetic | combination induced voltage in each phase can be restrained small, As a result, high rotation of the motor 10 can be achieved.

Note that, in the winding mode in which the windings 13 are connected in series in each phase as in the present embodiment, the sum of the induced voltages generated in the respective windings for each phase becomes the combined induced voltage. The voltage tends to increase. Therefore, by providing the protrusions 24a to 24d on the rotor 21 as described above in a configuration in which the winding 13 is in series in each phase, the effect of suppressing the combined induced voltage can be obtained more remarkably, and the motor It is more suitable to increase the rotation speed of 10.

Further, when the magnetic poles Mn and Ms having the magnetic force forcing and the protrusions 24a to 24d of the rotor core 21 having no magnetic force forcing are arranged in the circumferential direction, the magnetic pole Mn (or the magnetic pole Ms) The magnetic flux density changes sharply at the boundaries between the protrusions 24a to 24d, which may contribute to an increase in cogging torque. However, the phase change of the cogging torque is caused by changing the shape of the protrusions 24a to 24d of the rotor core 21. The cogging torque can be suppressed by shifting.

In addition, since the rotor 21 includes the protrusions 24a to 24d, the field-weakening current supplied to the winding 13 can be suppressed to a small value. Since the field weakening current can be reduced, the permanent magnet 25 is difficult to demagnetize during field weakening control, and the copper loss of the winding 13 can be suppressed. In other words, since the amount of flux linkage that can be reduced with the same amount of field-weakening current increases, higher rotation by field-weakening control can be obtained more effectively.

(2) The magnet magnetic poles Mn and Ms are arranged so that their circumferential centers coincide with the reference lines X3, X4, X7, and X8, respectively, and at least one of the protrusions 24a to 24d has the circumferential center as a reference It arrange | positions so that it may shift | deviate with respect to line X1, X2, X5, X6.

According to this configuration, the phase of the cogging torque generated when the rotor 21 rotates can be shifted, so that the cogging torque can be prevented from maximizing at a specific frequency. Thereby, the vibration generated due to the cogging torque can be suppressed.

(3) At least one of the protrusions 24a to 24d is set so that the open angle of the outer peripheral surface 28 is different from the open angles θn and θs of the outer peripheral surfaces 26 and 27 of the magnet magnetic poles Mn and Ms (permanent magnet 25). Is done.

This configuration can also shift the phase of the cogging torque generated when the rotor 21 rotates, so that the cogging torque can be prevented from maximizing at a specific frequency. Thereby, the vibration generated due to the cogging torque can be suppressed.

In addition, you may change the said embodiment as follows.
-In the rotor 21 of the said embodiment, as shown in FIG. 5, you may form the slit hole 22a extended along the radial direction of the rotating shaft 23 in the rotor core 22. As shown in FIG. In the example shown in the figure, the slit holes 22a are arranged at intervals of 90 ° in the circumferential direction, and are adjacent to the circumferentially adjacent projections 24a and 24b and the boundary between the projections 24c and 24d in the circumferential direction. It is provided at the boundary between the magnet magnetic poles Mn and Ms, respectively. Moreover, each slit hole 22a has penetrated the rotor core 22 to the axial direction. Each of these slit holes 22a is a gap, and has a magnetic resistance larger than that of the magnetic metal rotor core 22, so that the magnetic flux of each permanent magnet 25 passing through the rotor core 22 by each slit hole 22a is projected in the circumferential direction. It is possible to guide to 24d suitably (see the broken arrow in the figure).

Thereby, each of the protrusions 24a to 24d functions as a pseudo magnetic pole (core magnetic pole) by the magnetic flux action of the magnet magnetic poles Mn and Ms (permanent magnet 25) adjacent in the circumferential direction. That is, the protrusions 24a and 24c adjacent to the N-pole magnet magnetic pole Mn in the circumferential direction are configured as the S-pole core magnetic pole Rs, and the protrusions 24b and 24d adjacent to the S-pole magnet magnetic pole Ms in the circumferential direction are the N pole. The core magnetic pole Rn is configured.

Here, in the above embodiment, since the slit hole 22a as in the configuration shown in FIG. 5 is not formed in the rotor core 22, the magnetic fluxes of the magnetic poles Mn and Ms (magnet flux) are short-circuited between the different poles. Almost no flow into the protrusions 24a to 24d. This prevents magnetic poles from being formed by the magnetic flux from being formed on the protrusions 24a to 24d. As a result, each of the protrusions 24a to 24d is configured as a magnetic flux allowing portion that allows generation of field weakening magnetic flux (linkage magnetic flux φy caused by field weakening current) in the winding 13. Such a configuration is difficult to earn magnet torque and is disadvantageous in terms of increasing torque, but is advantageous in terms of increasing rotation as described above.

On the other hand, in the configuration shown in FIG. 5, each of the protrusions 24a to 24d functions as the core magnetic poles Rn and Rs by the slit holes 22a formed in the rotor core 22, and therefore the core magnetic poles Rn and Rs (projections 24a to 24d). This makes it difficult for field-weakening magnetic flux (linkage magnetic flux generated by field-weakening current) of winding 13 to be generated. This is disadvantageous in terms of increasing the rotation speed compared to the configuration in which the protrusions 24a to 24d are the magnetic flux allowing portions as in the above embodiment, but is advantageous in terms of increasing the torque.

That is, it is possible to adjust the output characteristics (torque and rotation speed) of the motor depending on whether the protrusions 24a to 24d function as magnetic flux allowance portions or the core magnetic poles Rn and Rs as in the above embodiment. Become. Further, when the protrusions 24a to 24d are caused to function as the core magnetic poles Rn and Rs, the amount of magnet magnetic flux induced to the core magnetic poles Rn and Rs (protrusions 24a to 24d) is adjusted (for example, the shape of the slit hole 22a, etc. The output characteristics (torque and rotation speed) of the motor can be adjusted by changing the configuration.

In the rotor 21 of the above-described embodiment, the magnet poles Mn and Ms (permanent magnet 25) are arranged at 180 ° facing positions with the same pole, but it is not particularly limited thereto.
For example, the magnet magnetic poles Mn and Ms (permanent magnets 25) may be alternately provided on the half circumference of the rotor core 22 as N poles and S poles, and the protrusions 24a to 24d may be provided on the remaining half circumference. With such a configuration, the same advantage as the advantage (3) of the above embodiment can be obtained.

The rotor 21 of the above embodiment has an SPM structure in which the permanent magnets 25 constituting the magnet magnetic poles Mn and Ms are fixed to the outer peripheral surface of the rotor core 22. However, the present invention is not particularly limited to this, and each magnet An embedded magnet type structure (IPM structure) in which a permanent magnet is embedded in the rotor core 22 at the magnetic poles Mn and Ms may be used. This configuration is advantageous in that it suppresses demagnetization of the permanent magnet during field-weakening control.

In the above embodiment, the windings of each phase, that is, the U-phase windings U1 to U4, the V-phase windings V1 to V4, and the W-phase windings W1 to W4 are connected in series. However, the winding mode may be changed as appropriate.

For example, in the example shown in FIG. 6, in the U phase, the windings U1, U2 are connected in series, and the windings U3, U4 are connected in series. The series pair of the windings U1, U2 and the windings U3, U4 Are connected in parallel. Similarly, in the V phase, the windings V1 and V2 are connected in series, and the windings V3 and V4 are connected in series. The series pair of the windings V1 and V2 and the series pair of the windings V3 and V4 are parallel. It is connected. Similarly, in the W phase, the windings W1, W2 are connected in series, and the windings W3, W4 are connected in series. The series pair of the windings W1, W2 and the series pair of the windings W3, W4 Are connected in parallel.

When the winding mode of FIG. 6 is applied to the configuration of the rotor 21 of the above embodiment (see FIG. 1), for example, in the U phase, induced voltages having the same magnitude are generated in the winding U1 and the winding U3, The induced voltages having the same magnitude are generated in the winding U2 and the winding U4. For this reason, the combined induced voltage generated in the series pair of the windings U1 and U2 is substantially equal to the combined induced voltage generated in the series pair of the windings U3 and U4. As a result, a decrease in the induced voltage due to the provision of the protrusions 24a to 24d always occurs in both the series pair of the windings U1 and U2 and the series pair of the windings U3 and U4. Since the series pair of the windings U1 and U2 and the series pair of the windings U3 and U4 are parallel, the combined induced voltage in the entire U-phase winding is the combined induced voltage of the series pair of the windings U1 and U2 ( And the combined induced voltage of the series pair of windings U3 and U4), and the combined induced voltage can be effectively suppressed.

Here, when the winding U2 and the winding U3 are interchanged in the example shown in FIG. 6, that is, the windings U1 and U3 having the same magnitude of the induced voltage are connected in series and the magnitude of the induced voltage is the same. Consider the case where the windings U2 and U4 are in series. In this case, the reduction of the induced voltage due to the provision of the protrusions 24a to 24d occurs only in one of the series pair of the windings U2 and U4 and the series pair of the windings U1 and U3, and the induced voltage is reduced on the other side. do not do. And since the series pair of winding U1, U3 and the series pair of winding U2, U4 are parallel, it is disadvantageous at the point which suppresses the synthetic | combination induced voltage in the whole U-phase winding effectively. Similarly, when the U-phase windings U1 to U4 are arranged in parallel, similarly, it is disadvantageous in that the combined induced voltage in the entire U-phase winding is effectively suppressed.

As described above, the windings (for example, the U-phase winding U1 and the U-phase winding U2) facing the magnet magnetic pole Mn (magnet magnetic pole Ms) and the protrusion at the predetermined rotational position of the rotor 21 are connected in series. . As a result, the induced voltages having opposite polarities (reverse phases) generated in the in-phase windings connected in series can be added to obtain a combined induced voltage. Thereby, the synthetic | combination induced voltage in each phase can be suppressed effectively.

In the example of FIG. 6, in the U phase, the windings U1 and U2 are a series pair and the windings U3 and U4 are a series pair. However, the windings U1 and U4 and the windings U2 and U3 are respectively Similar advantages can be obtained as a series pair. The same change can be made in the V phase and the W phase.

In the example of FIG. 6, in the U phase, the series pair of the windings U1 and U2 and the series pair of the windings U3 and U4 are connected in parallel. , U2 and the series pair of windings U3, U4 may be separated, and a pair of inverters may be provided to supply a U-phase drive current to each of the separated series pairs. With this configuration, the same advantages can be obtained. The same change can be made in the V phase and the W phase.

Moreover, in the example shown in the said embodiment (refer FIG. 2) and FIG. 6, although the connection aspect of the coil | winding was made into the star connection, it is not restricted to this, For example, it is good also as a delta connection.
In the above embodiment, the total number of magnet magnetic poles Mn and Ms in the rotor 21 is four and the number of windings 13 (slot number) of the stator 11 is twelve. The number of 13 can be appropriately changed according to the configuration. For example, the total number of magnet magnetic poles Mn and Ms and the number of windings 13 so that the relationship between the total number of magnet magnetic poles Mn and Ms and the number of windings 13 is n: 3n (where n is an integer of 2 or more). May be changed as appropriate. If the total number of magnet magnetic poles Mn and Ms is an even number as in the above embodiment, the number of magnet magnetic poles Mn and Ms can be the same, and a magnetically balanced configuration can be achieved.

Further, the relationship between the total number of magnet magnetic poles Mn and Ms and the number of windings 13 is not necessarily n: 3n (where n is an integer of 2 or more). The relationship with the number of lines 13 may be 5:12, 7:12, or the like.

FIG. 7 shows an example of the motor 30 in which the relationship between the total number of magnet magnetic poles Mn and Ms and the number of windings 13 is 5:12. In the example of FIG. 7, the same components as those in the above embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and different portions will be described in detail.

In the motor 30 shown in the figure, the 12 windings 13 of the stator 11 are classified according to the supplied three-phase drive currents (U phase, V phase, W phase), and are counterclockwise in FIG. In this order, U1, bar U2, bar V1, V2, W1, bar W2, bar U1, U2, V1, bar V2, bar W1, W2. In addition, U phase winding bar U1, bar U2, V phase winding bar V1 with respect to U phase windings U1, U2, V phase windings V1, V2 and W phase windings W1, W2 constituted by positive windings. , Bar V2, W-phase winding bar W1, bar W2 are constituted by reverse winding. Further, the U-phase winding U1 and the bar U1 are placed at positions facing each other by 180 °, and similarly, the U-phase winding U2 and the bar U2 are placed at positions facing each other by 180 °. The same applies to the other phases (V phase and W phase).

U-phase windings U1, U2, U1 and U2 are connected in series. Similarly, V-phase windings V1, V2, V1 and V2 are connected in series, and W-phase winding W1. , W2, bar W1, and bar W2 are connected in series. The U-phase windings U1, U2, U1 and U2 are supplied with U-phase drive current. As a result, the reverse winding U-phase winding bars U1 and U2 are always excited with the opposite polarity (reverse phase) with respect to the forward winding U-phase windings U1 and U2, but the excitation timing is the same. . The same applies to the other phases (V phase and W phase). The windings of each phase are supplied with a drive current set by regarding the number of poles of the rotor 31 as twice the number of magnet magnetic poles Mn and Ms (that is, 10 poles in this example).

A magnetic pole set Pa in which three magnet magnetic poles Ms and two magnet magnetic poles Mn are alternately arranged adjacent to each other in the circumferential direction and five protrusions 24a to 24e of the rotor core 22 are provided on the outer periphery of the rotor 31 of the motor 30. Is provided. Specifically, the magnetic pole set Pa is provided on the half of the outer periphery of the rotor 31, and the protrusions 24a to 24e are provided in the remaining half of the range. Protrusions 24a to 24e are arranged on opposite sides of the magnet magnetic poles Mn and Ms in the circumferential direction.

In the above configuration, when the rotor 31 rotates at high speed (when the field weakening control is performed), for example, when the S-pole magnet magnetic pole Ms is opposed to the U-phase winding U1 in the radial direction, the protrusion 24a of the rotor core 22 on the opposite side in the circumferential direction. Is opposed to the U-phase winding bar U1 in the radial direction (see FIG. 7). That is, the magnet magnetic pole Ms and the protrusion 24a are simultaneously opposed to the U-phase winding U1 and the bar U1 that are excited in opposite phases (same timing).

At this time, the field weakening current is supplied to the U-phase winding U1 and the bar U1, but in the U-phase winding U1, the magnetic flux (magnetic flux inward in the radial direction) of the opposing magnet magnetic pole Ms is weakened. The flux linkage φx that exceeds the flux linkage caused by the current (linkage flux outward in the radial direction) and passes inward in the radial direction is generated in the U-phase winding U1.

On the other hand, in the U-phase winding bar U1, since the portion of the rotor 31 that faces is the protrusion 24a of the rotor core 22, the interlinkage magnetic flux φy due to the field weakening current does not disappear, and the U-phase winding bar U1 has no chain. The cross magnetic flux φy passes toward the outside in the radial direction. As described above, the magnetic flux My that has the opposite phase to the magnetic flux φx generated in the U-phase winding U1 by the magnet magnetic pole Ms is generated in the U-phase winding bar U1. As a result, the induced voltage generated in the U-phase winding bar U1 by the linkage flux φy is opposite in polarity (reverse phase) to the induced voltage generated in the U-phase winding U1 by the linkage flux φx. The combined induced voltage at the line U1 and the bar U1 can be kept small. As described above, since the combined induction voltage can be suppressed in each phase, the motor 30 can be rotated at a high speed.

Next, the arrangement of the magnet magnetic poles Mn and Ms and the protrusions 24a to 24e of the rotor 31 will be described.
As in the above embodiment, the total number of magnetic poles Mn and Ms is n, and 2n reference lines extending radially from the rotation axis of the rotor 31 (axis L of the rotation shaft 23) are equiangularly spaced in the circumferential direction. Set to. In the rotor 31 of the same example, as shown in FIG. 8, since the total number of magnet magnetic poles Mn and Ms is 5, ten reference lines X1 to X10 are sequentially set at equal intervals of 36 ° in the clockwise direction.

The magnet magnetic poles Mn and Ms are arranged so that their circumferential centers coincide with any of the ten reference lines X1 to X10.
Specifically, the three magnetic poles Ms of S poles are arranged so that their circumferential centers coincide with the reference lines X1, X3, and X5, respectively, and the two magnetic poles Mn of N poles are arranged at their circumferential centers. Are arranged so as to coincide with the reference lines X2 and X4, respectively. That is, the interval (open angle) between the circumferential centers of the magnet magnetic poles Mn and Ms is set to 36 °.

On the other hand, the protrusions 24a to 24e are arranged so that their circumferential centers C1 to C5 are deviated from any of the reference lines X1 to X10. Hereinafter, several arrangement patterns of the protrusions 24a to 24e will be exemplified.

In the following, the deviation angle of the circumferential center C1 of the protrusion 24a with respect to the reference line X6 is θa, the deviation angle of the circumferential center C2 of the protrusion 24b with respect to the reference line X7 is θb, and the circumference of the protrusion 24c with respect to the reference line X8. The deviation angle of the direction center C3 is θc, the deviation angle of the circumferential center C4 of the protrusion 24d with respect to the reference line X9 is θd, and the deviation angle of the circumferential center C5 of the protrusion 24e with respect to the reference line X10 is θe. Further, the description will be made assuming that the angle of deviation in the clockwise direction is a positive value.

(Arrangement pattern 5)
θa> 0 °
θb = θa
θc = 0 °
θd <0 °
θe = θd
(Arrangement pattern 6)
θa <0 °
θb = θa
θc = 0 °
θd> 0 °
θe = θd
(Arrangement pattern 7)
θa> 0 °, θb <0 °
θc = 0 °
θd = θa
θe = θb
(Arrangement pattern 8)
θa <0 °, θb> 0 °
θc = 0 °
θd = θa
θe = θb
(Arrangement pattern 9)
θa> 0 °, θb> 0 ° θc> 0 °, θd> 0 ° θe> 0 °
(Arrangement pattern 10)
θa <0 °, θb <0 ° θc <0 °, θd <0 ° θe <0 °
(Arrangement pattern 11)
θa + θb + θc + θd + θe = 0 ° (however, θa to θd are all set to different values).
Next, setting of the opening angles θn and θs of the outer peripheral surfaces 26 and 27 of the magnet magnetic poles Mn and Ms and the opening angles θ1 to θ5 of the outer peripheral surfaces 28 of the protrusions 24a to 24e will be described with reference to FIG.

The open angles θn and θs of the magnetic poles Mn and Ms are set to be equal to each other, and the open angles θ1 to θ5 of the protrusions 24a to 24e are set to be smaller than the open angles θn and θs. In the following, several setting patterns for the open angles θ1 to θ5 of the protrusions 24a to 24e will be exemplified.

(Open angle setting pattern 4)
θn = θs = α
θ1 = θ2 = θ3 = θ4 = θ5 = β
β <α
(Open angle setting pattern 5)
θ1 = θ2 = θ3 = θ4 = θ5 = α
α <θs <θn
In the setting patterns 4 and 5 described above, the opening angles θ1 to θ5 of the protrusions 24a to 24e are all set to be equal. However, the present invention is not limited to this, and the opening angles θ1 to θ5 are all different values. May be set.

In the configuration shown in FIG. 9, the centers of the protrusions 24a to 24e are arranged so as to coincide with the reference lines X6 to X10. However, the present invention is not limited to this, and any of the above arrangement patterns 5 to 11 and the above It is also possible to adopt a configuration in which any one of the opening angle setting patterns 4 and 5 is combined.

In the configuration shown in FIG. 7, the number of magnet magnetic poles Mn and Ms may be changed as appropriate. For example, three magnet magnetic poles Mn and two magnet magnetic poles Ms may be configured.
Further, the arrangement of the magnet magnetic poles Mn and Ms and the protrusions 24a to 24e in the rotor 31 is not limited to the example shown in FIG. 7, and the protrusion of the rotor core 22 is provided on the opposite side of the magnet magnetic poles Mn and Ms in the circumferential direction. For example, the configuration may be changed as shown in FIG.

In the configuration of FIG. 10, a protrusion 24f is formed to protrude from the rotor core 22 instead of the central magnet magnetic pole Ms in the magnetic pole set Pa of the configuration shown in FIG. 7, and the magnet magnetic pole Mn (N pole permanent) is formed on the opposite side in the circumferential direction. A magnet 25) is provided. According to this configuration, the same advantages as the configuration shown in FIG. 7 can be obtained, and furthermore, the rotor 31 is magnetically and mechanically balanced compared to the configuration shown in FIG. be able to.

Further, in the stator 11, it is not necessary that all the U-phase windings U1, U2, bar U1, and bar U2 are connected in series, and a pair of windings U1, U1 and a pair of windings U2, U2 are provided. It is good also as a structure which made each another separate serial pair. Moreover, it can change similarly also in V phase and W phase.

FIG. 7 shows an example in which the relationship between the total number of magnet magnetic poles Mn and Ms and the number of windings 13 is 5:12, but the present invention can also be applied to a configuration with 7:12. . In addition, the present invention can be applied to a configuration in which the total number of 5:12 (or 7:12) magnetic poles Mn and Ms and the number of windings 13 are each equal.

In the embodiment described above, in the circumferential direction of the rotor 21, a plurality (two) of protrusions ( protrusions 24 a and 24 b) between the N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms (between the magnetic pole pair P). And a pair of protrusions 24c and 24d). However, the present invention is not limited to this. For example, as shown in FIG. 11, one protrusion 24g and 24h may be arranged between the N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms.

Here, the arrangement of the protrusions 24g and 24h in the configuration shown in FIG. 11 will be described. The arrangement of the magnet magnetic poles Mn and Ms is the same as in the above embodiment.
The protrusions 24g and 24h are arranged such that their circumferential centers Cg and Ch are displaced from the circumferential center line CL between the magnetic poles Mn and Ms. The circumferential center line CL is a circumferential end face 25a (end face opposite to the S pole magnet magnetic pole Ms) near the protrusion of the N pole magnetic pole Mn (permanent magnet 25) in the circumferential direction of the rotor 21. To the circumferential end face 25b (end face opposite to the N-pole magnet magnetic pole Mn) near the protrusion of the S-pole magnet magnetic pole Ms (permanent magnet 25).

The circumferential centers Cg and Ch of the protrusions 24g and 24h are set so as to shift in the clockwise direction or the counterclockwise direction with respect to the circumferential center line CL. Further, the deviation angle of the circumferential center Cg of the protrusion 24g with respect to the circumferential center line CL and the deviation angle of the circumferential center Ch of the protrusion 24h with respect to the circumferential center line CL are not necessarily set to be equal. Different shift angles may be used.

In the configuration shown in FIG. 11, the open angles θn and θs of the outer peripheral surfaces 26 and 27 of the magnet magnetic poles Mn and Ms are set to be equal to each other, and the open angles θg and θh of the outer peripheral surfaces 28 of the protrusions 24g and 24h are The opening angles θn and θs of the magnet magnetic poles Mn and Ms are set differently.

According to the arrangement setting and the opening angle setting of the protrusions 24g and 24h as described above, cogging generated when the rotor 21 rotates in the configuration in which one protrusion 24g and 24h is arranged between the magnetic pole pairs P in the circumferential direction. The phase of the torque can be shifted, and the cogging torque can be prevented from maximizing at a specific frequency. Thereby, the vibration generated due to the cogging torque can be suppressed.

The configuration in which one protrusion is arranged between the magnetic poles in the circumferential direction as described above, and the arrangement of the protrusion and the setting of the opening angle are also applied to the rotor configuration as shown in FIGS. Applicable.

In the above embodiment, when viewed from the direction of the axis L, the outer peripheral surfaces of the protrusions 24a to 24d and the outer peripheral surfaces of the magnet magnetic poles Mn and Ms (each permanent magnet 25) are on the same circle with the axis L as the center. It is formed in the circular arc shape located in. That is, the outer diameters of the protrusions 24a to 24d and the outer diameters of the magnet magnetic poles Mn and Ms are formed to be equal. However, the present invention is not limited to this, and the outer diameters of the protrusions 24a to 24d may be different from the outer diameters of the magnet magnetic poles Mn and Ms.

For example, as shown in FIG. 12, the outer diameter D1 of each of the protrusions 24a to 24d may be set larger than the outer diameter D2 of each of the magnetic poles Mn and Ms (each permanent magnet 25). In the example shown in FIG. 12, the outer peripheral surfaces of the protrusions 24a to 24d have an arc shape centered on the axis L when viewed from the direction of the axis L, and the outer diameters D1 of the protrusions 24a to 24d are mutually different. equal. Further, the outer peripheral surfaces of the magnet magnetic poles Mn and Ms have an arc shape centered on the axis L when viewed from the direction of the axis L, and the outer diameters D2 of the magnet magnetic poles Mn and Ms are equal to each other.

According to such a configuration, the air gap (gap) between the stator teeth 12a and the inner peripheral surface of the stator becomes smaller at the protrusions 24a to 24d than at the magnetic poles Mn and Ms. That is, since each of the protrusions 24a to 24d comes closer to the inner peripheral surface of the tooth 12a, the interlinkage magnetic flux φy (see FIG. 1) due to the field weakening current can be increased. As a result, the combined induction voltage in each phase can be suppressed to a smaller value, which can contribute to further increase in the rotation speed of the motor 10.

Further, it is preferable to provide a cover 40 for preventing the permanent magnet 25 from scattering in the rotor 21 having the SPM structure. In the configuration shown in FIG. 12, since the outer diameter D2 of each permanent magnet 25 is smaller than the outer diameter D1 of each protrusion 24a to 24d, an opening 40a that exposes the outer peripheral surface of each protrusion 24a to 24d is formed in the cover 40. By forming the cover 40, the cover 40 can be disposed on the outer peripheral portion of the permanent magnet 25 while keeping the air gap between the protrusions 24a to 24d and the teeth 12a small, which is more preferable.

In this example, the outer peripheral surfaces of the protrusions 24a to 24d and the outer peripheral surfaces of the magnet magnetic poles Mn and Ms have an arc shape centered on the axis L. That is, the distance from the axis L to the outer peripheral surface of each of the protrusions 24a to 24d is uniform in the circumferential direction. Similarly, the distance between the axis L and the outer peripheral surface of each magnet magnetic pole Mn, Ms is uniform in the circumferential direction. However, the shapes of the outer peripheral surfaces of the protrusions 24a to 24d and the magnetic poles Mn and Ms are not limited to this, and the distance from the axis L to the outer peripheral surface may not be uniform in the circumferential direction. In this case, the distance at the point where the distance from the axis L to the outer peripheral surface is the longest in each of the protrusions 24a to 24d is the outermost diameter of each of the protrusions 24a to 24d, and the axis L in each of the magnetic poles Mn and Ms. The distance at the longest distance from the outer peripheral surface to the outer peripheral surface is defined as the outermost diameter of each of the magnetic poles Mn and Ms. The outermost diameters of the protrusions 24a to 24d are preferably set larger than the outermost diameters of the magnet magnetic poles Mn and Ms. In the example of FIG. 12, since the outer peripheral surface of each of the protrusions 24a to 24d and the outer peripheral surface of each of the magnetic poles Mn and Ms form an arc shape with the axis L as the center, the outer diameters D1 and D2 are respectively the protrusions. 24a to 24d and the outermost diameters of the magnetic poles Mn and Ms.

As shown in FIG. 13, the present invention may be applied to an embedded magnet type structure (IPM structure) in which the permanent magnets 41 n and 41 s constituting the magnetic poles Mn and Ms are embedded in the rotor core 22. Even in such an IPM structure, the arrangement of the magnetic poles Mn and Ms and the protrusions 24a to 24d and the open angles of the magnetic poles Mn and Ms and the protrusions 24a to 24d can be set in the same manner as in the above embodiment. It is.

In the configuration shown in FIG. 13, the rotor core 22 is formed with a pair of convex portions 42 projecting to the outer peripheral side, and the pair of convex portions 42 is configured with magnetic pole pairs P (magnet magnetic poles Mn and Ms), respectively. Yes. That is, each convex portion 42 of the rotor core 22 has a permanent magnet 41n (permanent magnet having an N pole on the outer peripheral side) and a permanent magnet 41s (outer periphery) forming an S pole magnet magnetic pole Ms. A permanent magnet whose side is an S pole).

Further, each permanent magnet 41n, 41s has an arc shape centered on the axis L of the rotating shaft 23. The center in the circumferential direction of each N-pole permanent magnet 41n is arranged to coincide with the reference lines X4 and X8, respectively, and the center in the circumferential direction of each S-pole permanent magnet 41s coincides with the reference lines X3 and X7, respectively. Are arranged to be.

In the configuration shown in FIG. 13, the outer peripheral surface of each convex portion 42 has an arc shape located on the same circle centered on the axis L, and the open angle of the outer peripheral surface of each convex portion 42 is 90 °. Is set. In the same example, the circumferential center position CP (boundary position between adjacent magnet magnetic poles Mn and Ms) between the N-pole permanent magnet 41n and the S-pole permanent magnet 41s in each convex portion 42 is the convex portion 42. It is comprised so that it may correspond with the circumferential direction center position. The opening angles θn and θs of the magnet magnetic poles Mn and Ms are angles from the circumferential center position CP between the permanent magnets 41n and 41s to the circumferential ends 42a and 42b of the outer peripheral surface of the convex portion 42, respectively. . That is, the open angles θn and θs of the magnetic poles Mn and Ms formed on the convex portion 42 are set to be ½ of the open angles of the convex portions 42, respectively. In this example, the open angles of the magnetic poles Mn and Ms are set. θn and θs are each set to 45 °.

Further, the rotor 21 shown in FIG. 14 is obtained by changing the configuration shown in FIG. 13, and a magnetoresistive hole 43 is formed between the permanent magnets 41 n and 41 s in each convex portion 42 of the rotor core 22. In the configuration shown in FIG. 14, each of the permanent magnets 41 n and 41 s has a rectangular shape when viewed in the axial direction, and a surface (radial inner surface) including a long side when viewed from the axial direction is orthogonal to the radial direction of the rotor 21. It is provided to do. Each magnetoresistive hole 43 has a shape corresponding to the end shape of the permanent magnets 41n and 41s. In this example, one of the vertices has a substantially triangular shape when viewed in the axial direction and faces radially inward. By forming each magnetoresistive hole 43, the generation of short-circuit magnetic flux (magnetic flux that is short-circuited through the rotor core 22) in the permanent magnets 41n and 41s is suppressed. As in the same example, in the configuration in which the magnetoresistive hole 43 is formed in the convex portion 42, the opening angle θn of the magnet magnetic pole Mn is the circumferential direction of the outer peripheral surface of the convex portion 42 from one circumferential end of the magnetoresistive hole 43. The opening angle θs of the magnet magnetic pole Ms is an angle from the other circumferential end of the magnetoresistive hole 43 to the other circumferential end 42b of the outer peripheral surface of the convex portion 42.

In each of the magnetic poles Mn and Ms having the configuration shown in FIG. 14, the shape of each permanent magnet 41 n and 41 s when viewed in the axial direction is a rectangle, but is not limited to this, for example, the axis L is the center. It may be arcuate.

Further, the magnet magnetic poles Mn and Ms may have a magnet configuration as shown in FIG. In the configuration shown in the figure, each of the magnetic poles Mn and Ms includes a pair of permanent magnets 51 embedded in the rotor core 22 (convex portion 42). Each permanent magnet 51 has a rectangular parallelepiped shape, and the pair of permanent magnets 51 in each of the magnetic poles Mn and Ms are arranged in a substantially V shape that extends to the outer peripheral side when viewed in the axial direction. The pair of permanent magnets 51 are provided symmetrically with respect to the circumferential center line in the circumferential direction. That is, in the case of this example, the symmetry axis of the pair of permanent magnets 51 having line symmetry is the center in the circumferential direction of the magnet magnetic poles Mn and Ms. The arrangement of the magnet magnetic poles Mn and Ms is the same as that of the above embodiment, and the circumferential center (the axis of symmetry of the permanent magnet 51) of the N magnetic poles Mn coincides with the reference lines X4 and X8, respectively. And the center in the circumferential direction of each of the S magnetic poles Ms (the axis of symmetry of the permanent magnet 51) is arranged so as to coincide with the reference lines X3 and X7, respectively. Note that the pair of permanent magnets 51 in each of the magnetic poles Mn and Ms are arranged so as to be within an angular range (in the example, a 45 ° range) obtained by dividing the convex portion 42 into two equal parts in the circumferential direction.

Further, in FIG. 15, the magnetization directions of the permanent magnets 51 of the N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms are indicated by solid arrows, and the tip end side of the arrow is the N pole, and the base end side of the arrow is the S pole. Represents. As indicated by this arrow, each permanent magnet 51 in the N-pole magnet magnetic pole Mn has N-poles on the surfaces facing each other (surface on the magnetic pole center side) so that the outer peripheral side of the magnet magnetic pole Mn is N-pole. Magnetized to appear. In addition, each permanent magnet 51 in the S magnetic pole Ms is magnetized so that the S pole appears on the surfaces facing each other (surface on the magnetic pole center side) so that the outer peripheral side of the magnet magnetic pole Ms becomes the S pole. .

According to such a configuration of the magnet magnetic poles Mn and Ms, the pair of permanent magnets 51 are embedded so as to form a substantially V shape that expands radially outward when viewed in the axial direction. The volume (the volume of the portion including the inter-magnet core portion 22b between the pair of permanent magnets 51 arranged in a V shape) can be increased. As a result, the reluctance torque can be increased, which can contribute to an increase in torque of the motor 10.

Further, the rotor 21 shown in FIG. 16 is provided with a magnetoresistive hole 52 similar to the magnetoresistive hole 43 (see FIG. 14) for each convex portion 42 having the configuration shown in FIG. The magnetoresistive holes 52 are formed between the outer peripheral side ends of the permanent magnets 51 adjacent in the circumferential direction between the N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms formed in the convex portion 42. Thus, the generation of short-circuit magnetic flux (magnetic flux that is short-circuited through the rotor core 22) in the permanent magnet 51 is suppressed. Even in this configuration, the opening angle θn of the magnet magnetic pole Mn is an angle from one end in the circumferential direction of the magnetoresistive hole 52 to one end 42a in the circumferential direction of the outer peripheral surface of the convex portion 42, and the opening angle θs of the magnetic pole Ms is The angle is from the other circumferential end of the magnetoresistive hole 52 to the other circumferential end 42 b of the outer peripheral surface of the convex portion 42.

As shown in FIG. 17, in the rotor 21 having the IPM structure, the outer diameter D1 of each protrusion 24g, 24h of the rotor core 22 is the outer diameter D2 of the magnetic poles Mn, Ms (the outer diameter of the rotor core 22 at the magnetic poles Mn, Ms). ) May be set larger. According to such a configuration, the air gap (gap) between the stator teeth 12a and the inner peripheral surface of the stator becomes smaller at the protrusions 24g and 24h than at the magnetic poles Mn and Ms. That is, since each protrusion 24g, 24h comes closer to the inner peripheral surface of the tooth 12a, the interlinkage magnetic flux φy (see FIG. 1) due to the field weakening current can be increased. As a result, the combined induction voltage in each phase can be suppressed to a smaller value, which can contribute to further increase in the rotation speed of the motor 10.

Note that the magnet configuration of the magnet magnetic poles Mn and Ms and the configuration (number and the like) of the protrusions between the magnetic pole pairs P in the configuration shown in FIG. 17 can be appropriately changed. For example, the magnet configuration of the magnet magnetic poles Mn and Ms is shown in FIG. Alternatively, a V-shaped arrangement as shown in FIG. 16 may be used.

In the configuration shown in FIG. 17, the outer peripheral surface of the rotor core 22 (the outer peripheral surface of each protrusion 24g, 24h and the outer peripheral surface of the magnet magnetic poles Mn, Ms) is formed in an arc shape centered on the axis L. It is not specifically limited to.

For example, as shown in FIG. 18, the outer peripheral surfaces of the protrusions 24g and 24h may be formed in an elliptical arc shape with the axis L as the center. Each of the protrusions 24g and 24h is formed so that the outer diameter becomes maximum (outer diameter D1) at the circumferential center position, and the outer diameter D1 is set larger than the outer diameter D2 of the magnet magnetic poles Mn and Ms. It is preferable. In the example shown in the figure, the outer peripheral surfaces of the magnet magnetic poles Mn and Ms are arcuate (outer diameter D2), and the outer diameters of the protrusions 24g and 24h are the magnet magnetic poles Mn and Ms over the entire circumferential direction. It is comprised so that it may become larger than the outer diameter D2.

Further, for example, as shown in FIG. 19, the entire circumference of the rotor core 22 may be formed in an elliptical shape with the axis L as the center. In this case, it is preferable that the boundary between the magnetic poles Mn and Ms in each magnetic pole pair P coincides with the elliptical short axis Ls of the rotor core 22. Even with such a configuration, the outer diameters of the protrusions 24g and 24h can be configured to be larger than the outer diameters of the magnet magnetic poles Mn and Ms.

According to the configuration shown in FIG. 18 or FIG. 19, the air gap (gap) between the stator teeth 12a and the inner peripheral surface of the stator is smaller at the protrusions 24g and 24h than at the magnetic poles Mn and Ms. Become. That is, since each protrusion 24g, 24h comes closer to the inner peripheral surface of the tooth 12a, the interlinkage magnetic flux φy (see FIG. 1) due to the field weakening current can be increased. As a result, the combined induction voltage in each phase can be suppressed to a smaller value, which can contribute to further increase in the rotation speed of the motor 10.

The configuration shown in FIG. 20 is a configuration in which slit holes (see FIG. 5) are formed in the rotor core 22 of the rotor 21 having the IPM structure shown in FIG. As shown in FIG. 20, the rotor core 22 is formed with four slit holes 22 c and 22 d extending along the radial direction of the rotating shaft 23. The slit hole 22c is provided between the protrusions 24a and 24b adjacent in the circumferential direction and between the protrusions 24c and 24d adjacent in the circumferential direction. Moreover, the slit hole 22d is provided in the boundary part between the magnet magnetic poles Mn and Mn adjacent to each other in the circumferential direction. Each slit hole 22c, 22d penetrates the rotor core 22 in the axial direction. By these slit holes 22c and 22d, the magnetic fluxes of the permanent magnets 41n and 41s passing through the rotor core 22 are guided to the protrusions 24a to 24d adjacent to each other in the circumferential direction (see the broken arrows in the figure), thereby Each of the protrusions 24a to 24d functions as a pseudo magnetic pole (core magnetic pole). That is, the protrusions 24a and 24c adjacent to the N-pole magnet magnetic pole Mn in the circumferential direction are configured as the S-pole core magnetic pole Rs, and the protrusions 24b and 24d adjacent to the S-pole magnet magnetic pole Ms in the circumferential direction are set to the N pole. The core magnetic pole Rn is configured.

In the configuration shown in FIG. 20, the deviation angles θa to θd of the protrusions 24a to 24d are set larger than 0 °. That is, the protrusions 24a to 24d are provided at positions shifted in the clockwise direction with respect to the reference lines X1, X2, X5, and X6. In such a setting, the slit holes 22c and 22d are not provided at equal intervals in the circumferential direction, but the slit holes 22c are arranged according to the deviation angles θa to θd of the protrusions 24a to 24d. preferable. Specifically, one slit hole 22c is formed at the center position between the circumferential centers C1 and C2 of the protrusions 24a and 24b in the circumferential direction, and the other slit hole 22c is formed between the protrusions 24c and 24d in the circumferential direction. It is preferably formed at the center position between the circumferential centers C3 and C4. This makes it possible to configure the slit hole 22c so as not to overlap the protrusions 24a to 24d in the radial direction. As a result, the magnetic fluxes of the magnet magnetic poles Mn and Ms are adjacent to the protrusions 24a to 24d adjacent in the circumferential direction. Can be suitably induced. In the example shown in the figure, the deviation angles θa to θd of the protrusions 24a to 24d are all set to the same angle, but the present invention is not limited to this.

In the example of FIG. 20, each permanent magnet 41n, 41s has an arc shape centered on the axis L of the rotating shaft 23. In addition to this, for example, as shown in FIG. The shape may be a rectangle. In the configuration shown in FIG. 21, each of the permanent magnets 41 n and 41 s is provided such that a surface (a radially inner side surface) including a long side when viewed from the axial direction is orthogonal to the radial direction of the rotor 21. ing.

In the configuration shown in FIG. 22, slit holes 22c and 22d (see FIG. 20) are formed in the rotor core 22 of the rotor 21 having the IPM structure shown in FIG. Even in this configuration, the magnetic fluxes of the magnetic poles Mn and Ms passing through the rotor core 22 are guided to the projecting portions 24a to 24d adjacent in the circumferential direction by the slit holes 22c and 22d (see the broken arrows in the figure). Thereby, the protrusions 24a to 24d function as pseudo magnetic poles (core magnetic poles Rn, Rs).

23, slit holes 22c and 22d (see FIG. 20) are formed in the rotor core 22 of the rotor 21 having the IPM structure shown in FIG. Even in this configuration, the magnetic fluxes of the magnetic poles Mn and Ms passing through the rotor core 22 are guided to the projecting portions 24a to 24d adjacent in the circumferential direction by the slit holes 22c and 22d (see the broken arrows in the figure). Thereby, the protrusions 24a to 24d function as pseudo magnetic poles (core magnetic poles Rn, Rs).

In the configuration shown in FIG. 23, the slit hole 22d is provided at the boundary portion between the magnet magnetic poles Mn adjacent to each other in the circumferential direction. However, the present invention is not particularly limited thereto, and the arrangement of the slit hole 22d and the like. The configuration may be changed as appropriate. For example, in the configuration shown in FIG. 24, one slit hole 22d is provided for each magnet magnetic pole Mn, Ms. More specifically, the slit hole 22d is provided along the circumferential center line (reference line X3, X4, X7, X8) of each magnet magnetic pole Mn, Ms. Even in such a configuration, the magnetic fluxes of the magnetic poles Mn and Ms passing through the rotor core 22 are guided to the projecting portions 24a to 24d adjacent in the circumferential direction by the slit holes 22c and 22d (indicated by broken lines in the figure). Thereby, the protrusions 24a to 24d function as pseudo magnetic poles (core magnetic poles Rn and Rs).

In the configuration shown in FIG. 25, slit holes 22c and 22d (see FIG. 20) are formed in the rotor core 22 of the rotor 21 having the IPM structure shown in FIG. Even in this configuration, the magnetic fluxes of the magnetic poles Mn and Ms passing through the rotor core 22 are guided to the projecting portions 24a to 24d adjacent in the circumferential direction by the slit holes 22c and 22d (see the broken arrows in the figure). Thereby, the protrusions 24a to 24d function as pseudo magnetic poles (core magnetic poles Rn, Rs). In the configuration shown in the figure, each slit hole 22d is provided at the boundary between the magnet magnetic poles Mn and Mn adjacent in the circumferential direction, but each slit hole 22d is provided in each magnet magnetic pole Mn and Ms as shown in FIG. You may provide along the circumferential direction centerline.

The configuration shown in FIG. 26 is a configuration in which four slit holes 22e and 22f extending along the radial direction of the rotating shaft 23 are formed in the rotor core 22 of the rotor 21 shown in FIG. The radially outer ends of the two slit holes 22e are formed so as to partially divide the protrusions 24g and 24h of the rotor core 22 in the circumferential direction. Specifically, one slit hole 22e is formed on the circumferential center line L1 of the protrusion 24g, and the radially outer end of the slit hole 22e extends into the protrusion 24g. The other slit hole 22e is formed on the circumferential center line L2 of the protrusion 24h, and the radially outer end of the slit hole 22e extends into the protrusion 24h. The slit hole 22f is provided at each boundary between the magnetic poles Mn and Mn adjacent in the circumferential direction. The slit holes 22e and 22f penetrate the rotor core 22 in the axial direction.

In such a configuration, the magnetic flux of the N-pole magnet magnetic pole Mn is guided by the slit holes 22e and 22f to a portion closer to the magnet magnetic pole Mn than the slit hole 22e in the protrusions 24g and 24h (in the figure, a broken line). See arrow). Thereby, the said part of protrusion 24g, 24h functions as the core magnetic pole Rs of S pole. Similarly, the magnetic flux of the S-pole magnet magnetic pole Ms is guided to the part closer to the magnet magnetic pole Ms than the slit hole 22e in the protrusions 24g and 24h by the slit holes 22e and 22f (indicated by the broken arrow in the figure). reference). Thereby, the said part of protrusion 24g, 24h functions as the core magnetic pole Rn of N pole.

In the configuration shown in FIG. 27, slit holes 22e and 22f (see FIG. 26) are formed in the rotor core 22 of the rotor 21 shown in FIG. Also in this configuration, the magnetic poles Mn and Ms are guided by the slit holes 22e and 22f, so that the core magnetic poles Rn and Rs are formed on both sides in the circumferential direction of the slit hole 22e in the protrusions 24g and 24h. It has become so.

In the configuration shown in FIG. 28, slit holes 22e and 22f (see FIG. 26) are formed in the rotor core 22 of the rotor 21 shown in FIG. Also in this configuration, the magnetic poles Mn and Ms are guided by the slit holes 22e and 22f, so that the core magnetic poles Rn and Rs are formed on both sides in the circumferential direction of the slit hole 22e in the protrusions 24g and 24h. It has become so.

In the configuration shown in FIG. 29, slit holes 22e and 22f (see FIG. 26) are formed in the rotor core 22 of the rotor 21 shown in FIG. As shown in the figure, each slit hole 22 f is preferably provided on the boundary between the magnetic poles Mn and Ms in each magnetic pole pair P, that is, on the elliptical short axis Ls of the rotor core 22. Moreover, it is preferable that each slit hole 22e is provided on the elliptical long axis Lt of the rotor core 22. Also in this configuration, the magnetic poles Mn and Ms are guided by the slit holes 22e and 22f, so that the core magnetic poles Rn and Rs are formed on both sides in the circumferential direction of the slit hole 22e in the protrusions 24g and 24h. It has become so.

30 is a configuration in which two slit holes 22g extending along the radial direction of the rotating shaft 23 are formed in the rotor core 22 of the rotor 31 shown in FIG. One slit hole 22g is provided at the boundary between the magnet magnetic pole Ms adjacent to the protrusion 24e and the magnet magnetic pole Mn adjacent to the magnet magnetic pole Ms. The other slit hole 22g is provided at the boundary between the magnet magnetic pole Ms adjacent to the protrusion 24a and the magnet magnetic pole Mn adjacent to the magnet magnetic pole Ms. According to such a configuration, the magnetic flux of each magnetic pole Ms immediately adjacent to each slit hole 22g is guided to the adjacent protrusions 24a and 24e by the slit hole 22g, whereby the protrusions 24a and 24e are It functions as an N-pole core magnetic pole Rn.

As shown in FIG. 31, one slit hole 22g is provided on the circumferential center line (reference line X1) of the magnetic pole Ms adjacent to the protrusion 24e, and the other slit hole 22g is adjacent to the protrusion 24a. You may provide on the circumferential center line (reference line X5) of the magnetic pole Ms. Even with such a configuration, the magnetic fluxes of the magnet poles Ms adjacent to the protrusions 24a and 24e can be guided by the slit hole 22g, so that the protrusions 24a and 24e have an N-pole core. It functions as the magnetic pole Rn.

32 is a configuration in which four slit holes 22h and 22i extending along the radial direction of the rotating shaft 23 are formed in the rotor core 22 of the rotor 31 shown in FIG. The two slit holes 22h are respectively provided at the boundary between the magnetic poles Mn and Ms adjacent in the circumferential direction. The two slit holes 22i are respectively provided between the protrusions 24a and 24b adjacent in the circumferential direction and between the protrusions 24d and 24e adjacent in the circumferential direction.

According to such a configuration, the protrusions 24a, 24b, 24d, 24e, and 24f can function as pseudo magnetic poles (core magnetic poles) by the magnetic flux rectification action of the slit holes 22h and 22i. Specifically, the protrusions 24a and 24e adjacent to the S-pole magnet magnetic pole Ms in the circumferential direction function as the N-pole core magnetic pole Rn by the magnetic flux rectification action of the slit holes 22h and 22i. Further, the protrusions 24b and 24d arranged on both sides in the circumferential direction of the N-pole magnet magnetic pole Mn function as the S-pole core magnetic pole Rs by the magnetic flux rectification action of each slit hole 22i. The protrusion 24f provided at a position sandwiched between the N-pole magnet magnetic poles Mn in the circumferential direction functions as the S-pole core magnetic pole Rs by the magnetic flux rectifying action of each slit hole 22h.

Note that the configuration such as the arrangement of the slit holes described above is not limited to the configuration shown in FIG. 32, and may be changed as shown in FIG. 33, for example. In the configuration shown in FIG. 33, the two slit holes 22i are provided between the projections 24a and 24b adjacent in the circumferential direction and between the projections 24d and 24e adjacent in the circumferential direction, as in the configuration of FIG. Are provided corresponding to each. The rotor core 22 is formed with slit holes 22k extending along the radial direction so as to be aligned with the circumferential centers of the magnet magnetic poles Mn and Ms. Even with such a configuration, the protrusions 24a, 24b, 24d, 24e, and 24f can function as pseudo magnetic poles (core magnetic poles Rn and Rs) by the magnetic flux rectifying action of the slit holes 22i and 22k.

In the above embodiment, the permanent magnet 25 is a sintered magnet, but other than this, for example, a bonded magnet may be used.
In the above embodiment, the present invention is embodied in the inner rotor type motor 10 in which the rotor 21 is disposed on the inner peripheral side of the stator 11, but the invention is not particularly limited thereto, and the rotor is disposed on the outer peripheral side of the stator. The present invention may be embodied in an outer rotor type motor.

In the above embodiment, the present invention is embodied in the radial gap type motor 10 in which the stator 11 and the rotor 21 are opposed to each other in the radial direction. However, the present invention is not particularly limited thereto, and the stator and the rotor are in the axial direction. The present invention may be applied to an axial gap type motor that faces the motor.

-The above-mentioned embodiment and each modification may be combined suitably.

Claims (7)

1. A stator having windings;
   A rotor that rotates in response to a rotating magnetic field generated by supplying a driving current to the winding; and
   The rotor includes a rotor core, and a first magnet magnetic pole, a second magnet magnetic pole, and a protrusion that are arranged side by side in the circumferential direction,
   The first magnet magnetic pole uses a permanent magnet provided on the rotor core,
   The second magnet magnetic pole uses a permanent magnet provided on the rotor core, and has a different polarity with respect to the first magnet magnetic pole,
   The protrusion is formed to protrude in the radial direction in the rotor core,
   The winding includes a first winding and a second winding, and the first winding and the second winding are excited at the same timing by the drive current, and Connected in series,
   The motor configured such that the first magnet magnetic pole or the second magnet magnetic pole is at a rotational position of the rotor facing the first winding, and the protrusion is opposed to the second winding.
2. The motor according to claim 1,
   The protrusion is at least one of a plurality of protrusions;
   The total number of the first and second magnet magnetic poles is n, and 2n reference lines extending in the radial direction from the rotation axis of the rotor are set at equiangular intervals in the circumferential direction,
   The first and second magnet magnetic poles are arranged so that their circumferential centers coincide with any of the reference lines,
   The plurality of protrusions are provided between the first and second magnet magnetic poles in the circumferential direction,
   At least one of the plurality of protrusions is a motor arranged such that a center in a circumferential direction thereof is shifted with respect to the reference line.
3. The motor according to claim 1,
   The total number of the first and second magnet magnetic poles is n, and 2n reference lines extending in the radial direction from the rotation axis of the rotor are set at equiangular intervals in the circumferential direction,
   The first and second magnet magnetic poles are arranged so that their circumferential centers coincide with any of the reference lines,
   One protrusion is provided between the first and second magnet magnetic poles in the circumferential direction,
   The protrusion is disposed in such a manner that the center in the circumferential direction is deviated from the center line between the first and second magnet magnetic poles in the circumferential direction.
4. The motor according to any one of claims 1 to 3,
   The motor in which the opening angle of the surface facing the stator in the protrusion is set to be different from the opening angle of the surface facing the stator in the first and second magnet magnetic poles.
5. The motor according to any one of claims 1 to 4,
   A motor in which the outermost diameter of the protrusion is set larger than the outermost diameter of the first magnet magnetic pole and the outermost diameter of the second magnet magnetic pole.
6. The motor according to any one of claims 1 to 5,
   Each of the first and second magnet magnetic poles is a motor in which the permanent magnet is embedded in the rotor core.
7. The motor according to claim 6, wherein
   Each of the first and second magnet magnetic poles is provided with a motor in which a pair of permanent magnets is provided so as to form a substantially V-shape extending radially outward as viewed in the axial direction.

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