JP6657928B2 - Motor and method of adjusting magnetic flux of motor - Google Patents

Description

  The present invention relates to a motor and a method of adjusting magnetic flux of the motor.

  Conventionally, a permanent magnet motor such as a brushless motor includes, as shown in Patent Document 1, 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, The rotor rotates by receiving a rotating magnetic field generated by supplying a driving current to the winding of the stator.

JP 2014-135852 A

  In the above-described permanent magnet motor, the higher the rotation speed of the rotor, 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 lowers the motor output. This hinders the motor from rotating at a high speed. Therefore, by reducing the magnetic force of the rotor magnetic poles, for example, by reducing the size of the permanent magnet of the rotor, it is possible to suppress the induced voltage at the time of high rotation of the rotor, but the resulting torque also decreases. Therefore, there is still room for improvement in this respect.

  SUMMARY An advantage of some aspects of the invention is to provide a motor and a motor magnetic flux adjustment method capable of achieving high rotation while suppressing a decrease in torque.

A motor that solves the above problem is a motor in which a rotor rotates by receiving a rotating magnetic field generated by supplying a drive current to a winding of a stator, and the windings are driven at the same timing by the drive current. A first winding and a second winding that are excited and connected in series, wherein the rotor has a magnet magnetic pole using a permanent magnet, a core magnetic pole using a part of a rotor core, and a core magnetic pole using a part of a rotor core. A magnetic adjustment unit for adjusting the flowing magnetic flux, wherein the magnet magnetic pole is configured to face the second winding at a rotational position of the rotor facing the first winding. The magnet pole and the core pole are provided on both the north pole and the south pole of the rotor, and the core poles of the north pole and the south pole are respectively adjacent to the different core poles in the circumferential direction, The opposite pole Pole adjacent to the magnet poles of different polarities at the side opposite to the said magnetic adjusting unit is provided on the core magnetic pole boundary portion between the different poles adjacent in the circumferential direction in the rotor core.

  According to this configuration, the rotor magnetic poles facing the first winding and the second winding having the same excitation timing at predetermined rotation positions are a magnet magnetic pole using a permanent magnet and a core using a part of the rotor core. The configuration includes a magnetic pole. That is, instead of weakening the magnetic force of all the rotor magnetic poles facing the first winding and the second winding having the same excitation timing, some of the magnetic poles are used as the core magnetic poles to weaken the magnetic force toward the stator. Configuration. Thereby, while suppressing the decrease in torque as much as possible, the combined induced voltage in the first and second windings (the induced voltage generated in the first winding by the magnetic force of the magnet magnetic pole and the second induced voltage in the second winding by the magnetic force of the core magnetic pole). An induced voltage generated by combining an induced voltage generated in the winding) can be reduced, and the rotation speed of the motor can be increased.

  In the winding mode in which the first and second windings excited at the same timing are connected in series, the sum of the induced voltages generated in the first and second windings is the combined induced voltage. , The synthetic induced voltage tends to increase. For this reason, by using the magnetic pole configuration of the rotor in the configuration in which the first and second windings are connected in series, the effect of suppressing the combined induced voltage can be obtained more remarkably, and the rotation speed of the motor can be increased. It is more suitable to achieve.

  Further, since the rotor is provided with a magnetic adjustment unit for adjusting the magnetic flux flowing through the core magnetic pole, the output characteristics (torque and rotation speed) of the motor can be easily adjusted to desired values by changing the configuration of the magnetic adjustment unit. It becomes possible.

  According to this configuration, the magnetic adjustment unit is provided at the boundary between the different magnetic poles of the rotor core. Therefore, by changing the configuration of the magnetic adjustment unit, it is possible to adjust the amount of magnet magnetic flux (magnetic flux of the magnet magnetic pole) that is short-circuited between adjacent core magnetic poles. That is, the magnetic force of the core magnetic pole can be adjusted by changing the configuration of the magnetic adjustment unit, and the torque value can be easily adjusted to a desired value. Further, by changing the configuration of the magnetic adjustment unit, it is possible to adjust the ease with which the magnetic flux (d-axis magnetic flux) generated by the supply of the field weakening current to the winding passes through the core magnetic pole.

In the motor described above, it is preferable that the magnetic adjustment unit includes a slit portion extending along a radial direction.
According to this configuration, the output characteristics (torque and rotation speed) of the motor can be easily set to desired values by changing the configuration of the slit portion (for example, the radial length and the axial length of the slit portion) in the magnetic adjustment unit. Can be adjusted.

In the motor described above, it is preferable that the magnetic adjustment unit includes a bridge unit that connects a pair of side surfaces of the slit unit that face each other in a circumferential direction.
According to this configuration, the output characteristics (torque and rotation speed) of the motor can be easily adjusted to desired values by changing the configuration (number, axial and radial dimensions, etc.) of the bridge portion in the magnetic adjustment unit. Becomes possible.

In the motor, it is preferable that the field weakening control is configured to be executable.
According to this configuration, the induced voltage generated in the winding is suppressed to a small value as described above, so that the field weakening current supplied to the winding can be suppressed to a small value. Since the field weakening current can be reduced, the permanent magnet is hardly demagnetized during the field weakening control, and the copper loss of the winding can be suppressed. In other words, since the amount of interlinkage magnetic flux that can be reduced by the same amount of the field weakening current increases, the rotation can be more effectively increased by the field weakening control.

  In the adjusting method of adjusting the magnetic flux flowing through the core magnetic pole in the motor, the magnetic flux flowing through the core magnetic pole by changing at least one of the number of the bridge portions, the axial dimension of the bridge portion, and the radial size of the bridge portion. Is preferably adjusted.

  According to this method, the output of the motor is adjusted by adjusting the magnetic flux flowing through the core magnetic pole by changing at least one of the number of bridge portions, the axial size of the bridge portion, and the radial size of the bridge portion in the magnetic adjustment portion. Characteristics (torque and rotation speed) can be easily adjusted to desired values.

  ADVANTAGE OF THE INVENTION According to the motor and the motor magnetic flux adjustment method of this invention, high rotation can be aimed at, suppressing the fall of a torque.

(A) is a top view of a motor of an embodiment, and (b) is a plan view of a rotor of the same form. (A)-(c) is a top view for explaining the change aspect of the number of bridge parts. 6 is a graph showing the relationship between the number of bridge portions and torque, and the relationship between the number of bridge portions and field weakening current. It is sectional drawing of the rotor of another example. It is sectional drawing of the rotor of another example.

Hereinafter, one embodiment of a motor and a method of adjusting a magnetic flux of the motor will be described.
As shown in FIG. 1A, the motor 10 of the present embodiment is configured as a brushless motor, and has a configuration in which a rotor 21 is disposed 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 are provided in the same number as the teeth 12a, and each of the teeth 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 supplied three-phase driving currents (U-phase, V-phase, and W-phase), and U1, V1,. W1, U2, V2, W2, U3, V3, W3, U4, V4, W4.

  Looking at 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 regular intervals in the circumferential direction (90 ° intervals). Similarly, W-phase windings W1 to W4 are arranged at equal intervals in the circumferential direction (90 ° intervals).

  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. The series circuit of the U-phase windings U1 to U4, the series circuit of the V-phase windings V1 to V4, and the series circuit of the W-phase windings W1 to W4 are star-connected or delta-connected.

[Rotor configuration]
As shown in FIG. 1B, the rotor 21 has an embedded magnet type structure (IPM structure) in which a permanent magnet 22 forming a magnetic pole is embedded in a rotor core 23. The rotor core 23 is formed in a cylindrical shape by stacking a plurality of core sheets made of a circular plate-shaped magnetic metal in the axial direction, and a rotation shaft 24 is inserted and fixed to the center of the rotor core 23. A fixing hole 23a is formed.

  The rotor 21 is configured as an 8-pole rotor in which N poles and S poles are alternately set at equal circumferential intervals (45 ° intervals) on the outer peripheral surface 23b of the rotor core 23. More specifically, the rotor 21 includes a pair of an N-pole magnet magnetic pole Mn, an S-pole magnet magnetic pole Ms, an N-pole core magnetic pole Cn, and an S-pole core magnetic pole Cs. Each magnet magnetic pole Mn, Ms is a magnetic pole using the permanent magnet 22, and each core magnetic pole Cn, Cs is a magnetic pole using a part of the rotor core 23.

  Each of the magnetic poles Mn and Ms of the north pole and the south pole has a pair of permanent magnets 22 embedded in the rotor core 23, respectively. In each of the magnet poles Mn and Ms, the pair of permanent magnets 22 are arranged in a substantially V-shape that expands toward the outer periphery when viewed in the axial direction, and the magnetic pole center line in the circumferential direction (the straight line L1 in FIG. (See FIG. 2). Each of the permanent magnets 22 has a rectangular parallelepiped shape. Further, the pair of permanent magnets 22 in each of the magnetic poles Mn and Ms equally divides the rotor 21 in the circumferential direction by the number of poles (the total number of the magnetic poles Mn and Ms and the core magnetic poles Cn and Cs, and 8 in this embodiment). Are arranged so as to be within the angle range (in the present embodiment, the range of 45 °). Each of the permanent magnets 22 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, and the like.

  In FIG. 1B, the magnetization directions of the permanent magnets 22 of the N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms are indicated by solid arrows, and the leading end of the arrow is the N pole and the base end of the arrow is the S pole. Is represented. As shown by the arrows, each of the permanent magnets 22 in the N-pole magnet magnetic pole Mn has an N pole on a surface facing each other (a surface on the magnetic pole center line side) in order to make the outer peripheral side of the magnetic pole Mn an N pole. It is magnetized so that the poles appear. Further, each permanent magnet 22 in the S-pole magnet magnetic pole Ms is magnetized so that the S-pole appears on the surface facing each other (the surface on the magnetic pole center line side) so that the outer peripheral side of the magnet magnetic pole Ms becomes the S-pole. ing.

Next, the arrangement of the magnet magnetic poles Mn and Ms and the core magnetic poles Cn and Cs will be described.
The N-pole magnet magnetic pole Mn and the S-pole magnet magnetic pole Ms are arranged adjacent to each other so that the interval between their circumferential center positions (magnetic pole centers) is 45 °. A pair of the magnet magnetic pole Mn and the S magnetic pole Ms is defined as a magnet magnetic pole pair P. Further, in the rotor 21 of the present embodiment, two magnet magnetic pole pairs P are provided at positions facing each other by 180 ° in the circumferential direction. More specifically, the N-pole magnet pole Mn of one magnet pole pair P and the N-pole magnet pole Mn of the other magnet pole pair P are arranged at 180 ° facing each other. The S-pole magnet magnetic pole Ms of the pair P and the S-pole magnet magnetic pole Ms of the other magnet pole pair P are arranged at positions facing each other by 180 °. That is, the magnet poles Mn and Ms (the permanent magnets 22) are provided to be point-symmetric about the axis L of the rotor 21 (the axis of the rotating shaft 24).

  An S-pole core magnetic pole Cs, which is a part of the rotor core 23, is formed adjacent to the N-pole magnet magnetic pole Mn in the circumferential direction (opposite to the S-pole magnet magnetic pole Ms). Similarly, an N-pole core magnetic pole Cn, which is a part of the rotor core 23, is formed adjacent to the S-pole magnet magnetic pole Ms in the circumferential direction (opposite to the N-pole magnet magnetic pole Mn). Further, the different core magnetic poles Cn and Cs are configured to be adjacent to each other in the circumferential direction. In other words, the magnetic poles on the outer peripheral surface of the rotor 21 are sequentially arranged in the clockwise direction in the order of N pole magnet pole Mn, S pole core pole Cs, N pole core pole Cn, S pole magnet pole Ms, N pole magnet pole. Mn,... Are repeated. Further, the magnet magnetic poles Mn and the core magnetic poles Cn constituting the N pole of the rotor 21 are alternately arranged such that their circumferential center positions are at equal angular intervals (90 ° intervals). The magnetic poles Ms and core magnetic poles Cs constituting the S pole are alternately arranged such that their circumferential center positions are at equal angular intervals (90 ° intervals).

  The N core magnetic pole Cn is configured to function as a pseudo magnetic pole by the magnetic flux action of the S magnetic pole Ms adjacent in the circumferential direction. The S-pole core magnetic pole Cs is configured to function as a pseudo magnetic pole by the magnetic flux action of the N-pole magnet magnetic pole Mn adjacent in the circumferential direction.

  More specifically, in the rotor core 23, a slit portion 25 (magnetic adjustment portion) extending in the radial direction is formed at a boundary between the core magnetic poles Cn and Cs adjacent in the circumferential direction. The boundary between the core magnetic poles Cn and Cs where the respective slit portions 25 are formed is composed of an N-pole magnet magnetic pole Mn (S-pole magnet magnetic pole Ms) of one magnet magnetic pole pair P and the other magnet magnetic pole pair P And a circumferential center position between the S-pole magnet magnetic pole Ms (N-pole magnet magnetic pole Mn). The slits 25 (boundary portions between the adjacent core magnetic poles Cn and Cs) and the boundary portions between the adjacent magnet magnetic poles Mn and Ms are alternately set at equal intervals in the circumferential direction (90 ° intervals in the present embodiment). Have been.

  Each slit portion 25 extends from a position near the fixing hole 23a of the rotor core 23 to a position near the outer peripheral surface 23b of the rotor core 23 along the radial direction. In the present embodiment, each slit 25 is a hole that penetrates the rotor core 23 in the axial direction. That is, each slit portion 25 is formed so as to penetrate through each of the core sheets constituting the rotor core 23.

  The core magnetic poles Cn and Cs circumferentially adjacent to each other across the slit 25 are connected by connecting portions 26a and 26b at both ends in the radial direction of the slit 25. Note that the radially outer connecting portion 26a is formed to be flush with the outer peripheral surface 23b of the rotor core 23, and the radially inner connecting portion 26b is formed on the inner peripheral surface of the rotor core 23 (the inner peripheral surface of the fixing hole 23a). ).

  In the rotor core 23, a magnetic resistance hole 27 is formed at a position on the inner peripheral side of the pair of permanent magnets 22 in each of the magnetic poles Mn and Ms. Each magnetoresistive hole 27 is a rectangular hole that is long in the radial direction when viewed in the axial direction, and is provided at the circumferential center of each of the magnetic poles Mn and Ms. That is, in the present embodiment, the center between the magnetic resistance holes 27 of the magnet magnetic poles Mn and Ms adjacent in the circumferential direction is set to 45 °. Further, each of the magnetoresistive holes 27 penetrates the rotor core 23 in the axial direction. That is, each of the magnetic resistance holes 27 penetrates each of the core sheets constituting the rotor core 23.

  Each magnetic resistance hole 27 suppresses a short circuit of magnetic flux between the magnet magnetic poles Mn and Ms adjacent in the circumferential direction. Further, each slit portion 25 suppresses a short circuit of the magnetic flux between the magnetic pole pairs P. That is, the magnetic fluxes of the magnet magnetic poles Mn and Ms passing through the inside of the rotor core 23 are suitably guided to the adjacent core magnetic poles Cn and Cs by the slits 25 and the magnetic resistance holes 27. The magnetic flux amount of the magnetic poles Cn and Cs is secured.

Next, the operation of the present 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, the magnetic poles formed on the stator 11 side by the supply of the three-phase drive currents have the same polarity for each of the windings U1 to W4 of each phase.

  As described above, the number of pole pairs of the rotor 21 (that is, the number of each of the north pole and the south pole) is equal to the number of windings U1 to W4 of each phase (“4” in the present embodiment). I have. Thus, when the rotor 21 rotates, for example, when one of the N poles (the magnet magnetic pole Mn and the core magnetic pole Cn) of the rotor 21 faces the U-phase winding U1 in the radial direction, the other N-pole becomes the U-phase winding. The coils U2 to U4 are radially opposed to each other (see FIG. 1A).

  Here, half of the four N poles of the rotor 21 are constituted by the core magnetic poles Cn, and each of the core magnetic poles Cn is a pseudo magnetic pole functioning by the magnetic field of the adjacent magnet magnetic pole Ms. The magnetic force applied to the stator 11 side is weaker than the provided magnet magnetic pole Mn. The same applies to the S pole (core magnetic pole Cs and magnet magnetic pole Ms) of the rotor 21.

  Thereby, for example, each of the interlinkage magnetic fluxes φx interlinking the U-phase windings U1 to U4 (the U-phase windings U1 and U3 in the example shown in FIG. The interlinkage magnetic flux φy interlinking the U-phase windings U1 to U4 (the U-phase windings U2 and U4 in the example shown in FIG. 1A) facing the core magnetic pole Cn is reduced. Therefore, the induced voltage generated in the U-phase winding (the winding facing the core magnetic pole Cn) where the linkage magnetic flux φy links is the U-phase winding (the winding facing the magnet magnetic pole Mn) where the linkage magnetic flux φx links. Line). Therefore, the combined induced voltage obtained by combining the induced voltages generated in the U-phase windings U1 to U4 is a pair of U-phase windings facing the core magnetic pole Cn (the U-phase windings U2 and U4 in FIG. 1A). At the same time, the amount of the induced voltage is reduced by the amount of the induced voltage. Here, the description has been given by taking as an example the reduction of the combined induced voltage when the U-phase windings U1 to U4 face the N pole (the magnet magnetic pole Mn and the core magnetic pole Cn) of the rotor 21, but the V-phase windings V1 to V4 The same applies to the W-phase windings W1 to W4, and the S-pole (the magnet magnetic pole Ms and the core magnetic pole Cs) of the rotor 21 similarly reduces the combined induced voltage due to the core magnetic pole Cs.

  When the rotor 21 rotates at a high speed, a field-weakening current (d-axis current) is supplied to the winding 13 in order to generate a d-axis magnetic flux φd (see FIG. 1B) to reduce the induced voltage. Field weakening control is performed.

  Here, in the present embodiment, since the slit portion 25 formed between the adjacent core magnetic poles Cn and Cs serves as a magnetic resistance, it is difficult for the d-axis magnetic flux φd to pass through the core magnetic poles Cn and Cs. For this reason, the amount of decrease in the induced voltage with respect to the magnitude of the field weakening current to be supplied is small. In other words, a large field weakening current is required to obtain a desired rotation speed in a high rotation range.

  On the other hand, since the slit portion 25 is formed between the adjacent core magnetic poles Cn and Cs, the short-circuit magnetic flux between the core magnetic poles Cn and Cs is reduced. For this reason, magnetic flux (effective magnetic flux contributing to the rotation of the rotor 21) induced from the magnet magnetic poles Mn and Ms to the outer peripheral side of the core magnetic poles Cn and Cs can be ensured, and the torque can be increased.

  In other words, there is a trade-off between achieving a high rotation (making the d-axis magnetic flux φd easily pass through the core magnetic poles Cn and Cs) and achieving a high torque (improving the magnetic force of the core magnetic poles Cn and Cs). They are in a relationship, and they can be adjusted by changing the magnetic path configuration between the adjacent core magnetic poles Cn and Cs (that is, the configuration of the slit portion 25).

  Hereinafter, an example of a configuration change of the slit portion 25 will be described with reference to FIGS. In the example shown in the figure, a bridge portion B is provided to connect between a pair of circumferentially opposed side surfaces 25a in the slit portion 25, and the slit portion 25 and the bridge portion B adjust the magnetic flux flowing through the core magnetic poles Cn and Cs. For the magnetic adjustment unit.

  2A to 2C show an example in which the number of bridge portions B provided in the slit portion 25 is changed, and FIG. 2A shows a configuration in which one bridge portion B is provided. FIG. 2B illustrates a configuration in which two bridge portions B are provided, and FIG. 2C illustrates a configuration in which three bridge portions B are provided. In this example, the position where the bridge portion B is provided is set so that the slit portion 25 is equally divided in the radial direction. The axial thickness of the bridge portion B is equal to the axial thickness of the core sheet.

  FIG. 3 is a graph showing the relationship between the number of the bridge portions B provided in the above-described manner, the torque T and the field weakening current Id (field weakening current necessary to obtain a desired rotation speed during field weakening control). It is.

  As shown in the graph, the obtained torque T decreases as the number of the bridge portions B increases. This is considered to be because the larger the number of the bridge portions B, the larger the magnet magnetic flux (magnetic flux of the magnet magnetic poles Mn and Ms) that short-circuits between the adjacent core magnetic poles Cn and Cs.

  On the other hand, the field weakening current Id (field weakening current required to obtain a desired rotation speed during field weakening control) decreases as the number of bridge portions B increases. That is, in the case where the field weakening current Id is constant, as the number of the bridge portions B increases, the d-axis magnetic flux φd (see FIG. 1) generated by the supply of the field weakening current Id to the winding 13 increases the core magnetic pole Cn. , Cs, so that the maximum rotation speed of the rotor 21 during the field-weakening control increases. If the field weakening current Id is increased, the permanent magnet 22 is easily demagnetized during the field weakening control, and the copper loss of the winding 13 is increased. Is desirably set in consideration of the demagnetization of the coil and the copper loss of the winding 13.

  Thus, by changing the number of the bridge portions B, the magnetic flux (magnet magnetic flux and d-axis magnetic flux φd) flowing through the core magnetic poles Cn and Cs changes, and the output characteristics (torque T and rotation speed) of the motor 10 change. I do. Therefore, the output characteristics (torque T and rotation speed) of the motor 10 can be easily adjusted to desired values by the number of the bridge portions B provided on the rotor 21.

Next, the characteristic effects of the present embodiment will be described.
(1) The windings 13 of the stator 11 are formed from four U-phase windings U1 to U4, V-phase windings V1 to V4, and W-phase windings W1 to W4 in accordance with the supplied three-phase driving currents. 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.

  The N pole of the rotor 21 is composed of a magnet magnetic pole Mn using a permanent magnet 22 and a core magnetic pole Cn using a part of the rotor core 23, and the magnet magnetic pole Mn is a U-, V-, or W-phase phase. At the rotation position of the rotor 21 facing one winding (for example, the U-phase windings U1 and U3), the core magnetic pole Cn faces the second winding (for example, the U-phase windings U2 and U4) in phase. Be composed. Similarly, the S pole of the rotor 21 includes a magnet magnetic pole Ms using the permanent magnet 22 and a core magnetic pole Cs using a part of the rotor core 23. The magnet magnetic pole Ms is any one of the U, V, and W phases. At the rotational position of the rotor 21 facing the first winding (for example, the U-phase windings U1 and U3), the core magnetic pole Cs faces the second winding (for example, the U-phase windings U2 and U4) in phase. It is configured as follows.

  According to this configuration, instead of weakening the magnetic force of all the N poles (or S poles) of the rotor 21 facing the in-phase winding 13, a part of them is used as the core magnetic pole Cn (core magnetic pole Cs) to reduce the magnetic force. Weakening. As a result, the combined induced voltage generated in the in-phase windings 13 by the magnetic poles of the rotor 21 can be suppressed to a minimum while suppressing the decrease in torque as much as possible. As a result, the rotation speed of the motor 10 can be increased.

  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 each winding in each phase is the combined induced voltage. The voltage tends to increase. Therefore, by providing the core magnetic poles Cn and Cs as described above in a configuration in which the windings 13 are connected in series in each phase, the effect of suppressing the combined induced voltage can be more remarkably obtained, and the height of the motor 10 can be increased. It is more suitable for achieving rotation.

  In the present embodiment, the rotor 21 includes the slit portion 25 and the bridge portion B as a magnetic adjustment portion for adjusting the magnetic flux flowing through the core magnetic poles Cn and Cs. Therefore, the output characteristics (torque T and rotation speed) of the motor 10 can be easily adjusted to desired values by changing the configuration of the slit portion 25 and the bridge portion B.

  (2) The magnet magnetic poles Mn and Ms and the core magnetic poles Cn and Cs are provided on both the N pole and the S pole of the rotor 21. The N-pole and S-pole core magnetic poles Cn, Cs are adjacent to the different pole core magnetic poles Cn, Cs in the circumferential direction, respectively, and are different pole magnet poles Mn on the side opposite to the different pole core poles Cn, Cs. , Ms. Further, the slit portion 25 and the bridge portion B as the magnetic adjustment portion are provided at a boundary portion between the differently adjacent core magnetic poles Cn and Cs in the rotor core 23 which are adjacent in the circumferential direction.

  According to this configuration, the amount of magnet magnetic flux (magnetic flux of magnet magnetic poles Mn and Ms) that short-circuits between circumferentially adjacent core magnetic poles Cn and Cs can be adjusted by changing the configuration of slit portion 25 and bridge portion B. . That is, the magnetic force of the core magnetic poles Cn and Cs can be adjusted by changing the configuration of the slit portion 25 and the bridge portion B, and the torque value can be easily adjusted to a desired value. Further, by changing the configuration of the slit portion 25 and the bridge portion B, the ease with which the magnetic flux (d-axis magnetic flux φd) generated by the supply of the field weakening current Id to the winding 13 passes through the core magnetic poles Cn and Cs is adjusted. It is possible to do.

  (3) Since the magnetic adjustment unit includes the bridge portion B that connects the pair of side surfaces 25a facing each other in the circumferential direction of the slit portion 25, the configuration of the bridge portion B (the number of the bridge portions B in the present embodiment) is changed. Thereby, the output characteristics (torque T and rotation speed) of the motor 10 can be easily adjusted to desired values.

  (4) The motor 10 is configured to be able to execute the field-weakening control, and is provided to the winding 13 by providing the rotor 21 with the core magnetic poles Cn and Cs that do not spontaneously emit magnetic flux as in the present embodiment. The field weakening current can be kept small. Since the field weakening current can be reduced, the permanent magnet 22 is hardly demagnetized during the field weakening control, and the copper loss of the winding 13 can be suppressed. In other words, since the amount of interlinkage magnetic flux that can be reduced by the same amount of the field weakening current increases, the rotation can be more effectively increased by the field weakening control.

  (5) In each of the magnetic poles Mn and Ms, the pair of permanent magnets 22 are buried so as to form a substantially V-shape that expands radially outward when viewed in the axial direction. It is possible to increase the volume of the portion including the inter-magnet core portion 23c between the arranged pair of permanent magnets 22). As a result, the reluctance torque can be increased, which can contribute to increasing the torque of the motor 10.

  Further, in the magnetic poles Mn and Ms in which the permanent magnets 22 are arranged in a V-shape as in the present embodiment, the magnetic resistance holes 27 for suppressing the short circuit of the magnetic flux between the magnetic poles Mn and Ms of different polarities are provided. It is provided radially inward. For this reason, the short circuit of the magnetic flux between the different magnetic poles Mn and Ms can be suitably suppressed by the magnetic resistance hole 27.

  (6) 2n U-phase windings U1 to U4, V-phase windings V1 to V4, and W-phase windings W1 to W4 (n is an integer of 2 or more, and n = 2 in the present embodiment) , And the number of each of the magnet magnetic poles Mn and Ms and the core magnetic poles Cn and Cs of the rotor 21 is n (that is, two). That is, since the magnetic poles Mn and Ms and the core magnetic poles Cn and Cs are configured to have the same number (half of the number of windings of each phase), the magnetic pole Mn and the core magnetic pole Cn (the magnet magnetic pole Ms and the core magnetic pole Cs) Can be alternately provided at equal intervals in the circumferential direction. Thereby, the magnet magnetic pole Mn and the core magnetic pole Cn (the magnet magnetic pole Ms and the core magnetic pole Cs) having different magnetic forces and masses are arranged in a good balance in the circumferential direction, and the rotor 21 is magnetically and mechanically excellent in balance. Configuration.

The above embodiment may be modified as follows.
In the above embodiment, the installation position of the bridge portion B is set so as to equally divide the slit portion 25 in the radial direction. However, the present invention is not limited to this, and the installation position of the bridge portion B in the slit portion 25 is set. The output characteristics (torque T and rotation speed) of the motor 10 can also be adjusted depending on whether it is provided radially outward or radially inward.

In the above embodiment, the output characteristics (torque T and rotation speed) of the motor 10 are adjusted by changing the number of the bridge portions B, but the present invention is not particularly limited to this.
For example, the magnetic flux flowing through the core magnetic poles Cn and Cs may be adjusted by changing the radial length of the bridge portion B. In this case, as the radial length of the bridge portion B is reduced, the magnetic flux (magnet magnetic flux and d-axis magnetic flux φd) becomes harder to pass between the core magnetic poles Cn and Cs, and the torque T and the field weakening current Id increase.

  Further, for example, as shown in FIG. 4, by changing the axial thickness Tb of the bridge component 31 constituting the bridge portion B in each core sheet 30 constituting the rotor core 23, the output characteristics of the motor 10 ( The torque T and the number of rotations) may be adjusted. In this case, as the thickness Tb in the axial direction of the bridge component 31 is made smaller than the thickness in the axial direction of the portion (core magnetic pole component 32) of the core sheet 30 that forms the core magnetic poles Cn and Cs, the core magnetic poles Cn and Cs become smaller. The magnetic flux (magnet magnetic flux and d-axis magnetic flux φd) hardly passes between them, and the torque T and the field weakening current Id increase.

  In this case, it is preferable that the bridge component 31 of each core sheet 30 is pressed in the axial direction so that the thickness Tb in the axial direction is reduced. By forming in such a manner, the bridge component 31 has a higher density than the core magnetic pole component 32, so that the reluctance of the bridge component 31 is increased, and the core connected via the bridge component 31 is also increased. It is possible to adjust the ease of passage of the magnetic flux between the magnetic poles Cn and Cs.

  In addition, at least two or more changes in the number of the bridge portions B, changes in the radial length of the bridge portions B, and changes in the axial length of the bridge portions B (the axial thickness Tb of the bridge constituting portion 31) are made. By combining them, the magnetic flux flowing through the core magnetic poles Cn and Cs (that is, the output characteristics of the motor 10) may be adjusted.

  In the above embodiment, the output characteristics (torque T and rotation speed) of the motor 10 are adjusted by providing the bridge portion B in the slit portion 25 and changing the configuration of the bridge portion B. It is not limited.

  For example, the magnetic flux flowing through the core magnetic poles Cn, Cs may be adjusted by changing the radial length of the slit portion 25 (that is, changing the radial length of the connecting portions 26a, 26b). In this case, the shorter the radial length of the slit portion 25 (ie, the longer the radial length of the connecting portions 26a and 26b), the more the magnetic flux (magnet magnetic flux and d-axis magnetic flux φd) flows between the core magnetic poles Cn and Cs. ) Easily passes, and the torque T and the field weakening current Id decrease.

  In this case, one of the connecting portions 26a and 26b is omitted, that is, the slit portion 25 is configured to extend to the outer peripheral surface 23b or the inner peripheral surface (the inner peripheral surface of the fixing hole 23a) of the rotor core 23. Is also good.

  Also, for example, as shown in FIG. 5, the magnetic flux flowing through the core magnetic poles Cn and Cs may be adjusted by changing the axial length of the slit portion 25. In the configuration shown in the figure, a slit portion 25 is formed in a part of the plurality of core sheets 30 constituting the rotor core 23, and the other core sheets 30 do not have the slit portion 25. Thus, by changing the number of core sheets having the slit portions 25 (core sheet 30a in the drawing) and the number of core sheets having no slit portions 25 (core sheet 30b in the drawing), the entire rotor core 23 can be viewed. The axial length (axial depth) of the slit portion 25 can be changed. In this case, as the axial length of the slit portion 25 is reduced (that is, the number of the core sheets 30 having the slit portion 25 is reduced), the magnetic flux (magnet magnetic flux and d-axis magnetic flux φd) between the core magnetic poles Cn and Cs is reduced. ) Becomes difficult to pass, and the torque T and the field weakening current Id increase.

  In the configuration shown in FIG. 5, the core sheet 30b having no slit portion 25 is laminated on the lower half, and the core sheet 30a having the slit portion 25 is laminated on the upper half. However, the present invention is not limited to this. The core sheets 30a and 30b may be alternately laminated.

  Further, the configuration in which the axial length of the slit portion 25 is changed as shown in the figure can be applied to the case where the shape of each core sheet 30 is the same. Specifically, in each core sheet 30, instead of forming a pair of slit portions 25 at 180 ° facing positions as in the above-described embodiment, only one of them is formed, and some of the core sheets 30 are turned 180 °. It is also possible to change the axial length of the slit portion 25 by stacking (rotating and stacking).

  In the above embodiment, only one slit portion 25 is provided in the region of the adjacent core magnetic poles Cn and Cs. However, for example, a plurality of slit portions 25 are provided in the region and the number of the slit portions 25 is changed. Accordingly, the magnetic flux flowing through the core magnetic poles Cn and Cs (that is, the output characteristics of the motor 10) may be adjusted.

In the above embodiment, the magnetic flux flowing through the core magnetic poles Cn and Cs (that is, the output characteristics of the motor 10) may be adjusted by providing an auxiliary magnet (permanent magnet) in the slit portion 25.
In the rotor core 23 of the above embodiment, the slit portion 25 is formed as a magnetic adjustment portion for adjusting the magnetic flux flowing through the core magnetic poles Cn and Cs, but the present invention is not particularly limited to this. For example, the magnetic flux flowing through the core magnetic poles Cn and Cs may be adjusted by demagnetizing a part of the rotor core 23 by laser irradiation.

  In the rotor 21 of the above embodiment, the N magnetic poles Mn and the core magnetic poles Cn are alternately arranged at regular intervals in the circumferential direction (90 ° intervals), and the magnetic poles Ms and the core magnetic poles are similarly arranged on the S pole side. Cs are alternately arranged at regular intervals in the circumferential direction (90 ° intervals), but are not particularly limited thereto. For example, an N-pole core magnetic pole Cn may be provided at a position 180 ° opposite to the N-pole magnet magnetic pole Mn. Similarly, an S-pole core magnetic pole Cs may be provided at a position 180 ° opposite to the S-pole magnet magnetic pole Ms.

  In the above-described embodiment, the number of the magnetic poles Mn and the number of the core magnetic poles Cn are the same (half of the number of the windings 13 of each phase and two) in, for example, the N pole of the rotor 21, but are always the same. No need. For example, three (or one) magnet magnetic poles Mn and one (or three) core magnetic poles Cn may be used. The same change may be made on the S pole side of the rotor (magnet pole Ms and core pole Cs).

  In the above embodiment, the core magnetic pole Cn and the core magnetic pole Cs are provided at the N pole and the S pole of the rotor 21, respectively. However, the present invention is not particularly limited thereto. For example, only one pole of the rotor 21 has the core magnetic pole. May be provided, and the other pole may be constituted entirely by magnet magnetic poles.

  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, respectively. However, the winding mode may be appropriately changed. For example, as a modification, a U-phase winding will be described as an example. The U-phase windings U1 and U2 are connected in series, the U-phase windings U3 and U4 are connected in series, and the U-phase windings U1 and U2 are connected in series. And a series pair of U-phase windings U3 and U4 may be connected in parallel.

  In the above embodiment, the rotor 21 has eight poles and the number of the windings 13 of the stator 11 is twelve (that is, a motor configuration of eight poles and twelve slots). Can be appropriately changed according to the configuration.

In the above embodiment, the permanent magnet 22 is a sintered magnet, but may be, for example, a bonded magnet.
In each of the magnetic poles Mn and Ms of the above embodiment, the pair of permanent magnets 22 buried in the rotor core 23 is arranged in a substantially V-shape that expands toward the outer peripheral side when viewed in the axial direction. However, the configuration of the permanent magnet in the magnetic poles Mn and Ms can be changed as appropriate. For example, a configuration in which one permanent magnet is provided for each magnet magnetic pole Mn, Ms may be adopted.

  Further, the rotor 21 of the above embodiment has an embedded magnet type structure (IPM structure) in which the permanent magnets 22 constituting the magnetic poles Mn and Ms are embedded in the rotor core 23. The permanent magnet may be a surface magnet type structure (SPM structure) fixed to the outer peripheral surface of the rotor core 23.

  In the above embodiment, the rotor 21 is embodied as the inner rotor type motor 10 arranged on the inner peripheral side of the stator 11. However, the present invention is not particularly limited to this, and the outer rotor type motor in which the rotor is arranged on the outer peripheral side of the stator 11. Motor may be embodied.

  In the above embodiment, the radial gap type motor 10 in which the stator 11 and the rotor 21 face in the radial direction is embodied. However, the present invention is not particularly limited to this, and the stator and the rotor face in the axial direction. The present invention may be applied to an axial gap type motor.

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

  10 motor, 11 stator, 12 stator core, 12a teeth, 13 winding, 21 rotor, 22 permanent magnet, 23 rotor core, 24 rotating shaft, 25 slit section (magnetic adjustment section), B ... Bridge part (magnetic adjustment part), Mn, Ms. Magnet magnetic pole, Cn, Cs. Core magnetic pole, U1 to U4 U phase winding, V1 to V4 V phase winding, W1 to W4 W phase winding.

Claims (5)

A motor in which a rotor rotates in response to a rotating magnetic field generated by a drive current being supplied to a winding of a stator,
The windings are excited at the same timing by the drive current, and include a first winding and a second winding connected in series,
The rotor includes a magnet magnetic pole using a permanent magnet, a core magnetic pole using a part of a rotor core, and a magnetic adjustment unit for adjusting a magnetic flux flowing through the core magnetic pole, and the magnetic magnetic pole includes the first winding. the core pole in the rotational position of the opposing rotor is configured to face the second winding and,
The magnet pole and the core pole are provided on both the north pole and the south pole of the rotor,
The core magnetic poles of the N pole and the S pole are each adjacent to a core pole of a different polarity in the circumferential direction, and are adjacent to the magnet pole of a different polarity on a side opposite to the core pole of the different polarity,
The motor , wherein the magnetic adjustment unit is provided at a boundary between the core poles having different polarities adjacent to each other in a circumferential direction in the rotor core . The motor according to claim 1 ,
The motor, wherein the magnetic adjustment unit includes a slit portion extending along a radial direction. The motor according to claim 2 ,
The motor according to claim 1, wherein the magnetic adjustment unit includes a bridge unit that connects a pair of side surfaces of the slit unit that face each other in a circumferential direction. The motor according to any one of claims 1 to 3 ,
A motor characterized in that field weakening control can be executed. An adjusting method for adjusting a magnetic flux flowing through the core magnetic pole in the motor according to claim 3 ,
A magnetic flux adjusting method for a motor, wherein the magnetic flux flowing through the core magnetic pole is adjusted by changing at least one of the number of the bridge portions, the axial size of the bridge portions, and the radial size of the bridge portions.

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