JP2012157236A - Brushless motor and brushless motor drive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor which can reduce torque ripples of both electric angle 6th-order and electric angle 12th-order components, and a brushless motor drive method.SOLUTION: A rotor core 16 is halved in an axial direction to form split rotor cores 16a and 16b. Then, to ensure that a magnetic skew at an electric angle of 60 degrees will be maintained between the magnetic pole of the rotor core 16 and the magnetic pole of a stator (tooth 9), the split rotor cores 16a and 16b are arranged so that they are displaced in one direction by only 6 degrees centering around the center line of rotation axis, respectively. This makes it possible to eliminate the torque ripple of an electric angle 12th-order component which develops in a brushless motor. Also, the stator has two different 3-phase windings wound at a slot pitch of 30 degrees in terms of an electric angle. These two different 3-phase windings have electrical continuity with a 30-degree phase difference.

Description

  The present invention relates to a brushless motor and a driving method of the brushless motor.

  In recent years, it has been desired to further increase the output of motors, and as one of them, the use of SC (segment conductor) windings in the stator has attracted attention, and various brushless motors in which the stator is provided with SC windings have been proposed (for example, patents). Reference 1).

  The SC winding refers to a winding in which a divided conductor called a segment is inserted into each slot of the stator core from the axial direction, and the opposite side is connected by welding or the like in a subsequent process to form a continuous winding. As a result, the divided conductor inserted into the slot can have a quadrangular cross section, and the occupation ratio of the winding in the slot is improved, contributing to higher output.

  Patent Document 1 discloses a stator in which segments are inserted and connected into 36 slots. Since there are 36 slots and a large number of slots and segments are inserted into the slots to form fine windings, torque ripple can be reduced.

  However, EPS motors and the like used for EPS (electric power steering) are required to further reduce torque ripple. This is not limited to the application, and in the first place, it is preferable that the torque ripple of the motor is preferably zero.

  On the other hand, motors are also strongly required to reduce costs. For example, Patent Document 2 discloses a motor of a continuous rotor in which the magnet is halved, but there is a problem that torque ripple increases because magnet poles and iron salient poles appear alternately.

Japanese Patent No. 3303773 JP 9-327139 A

  By the way, it is known that the basic order of torque ripple in a three-phase AC drive brushless motor is the number of poles × number of phases / 1 rotation, and is 6th order (6th electrical angle) per pair of poles. Yes. Also, the main electrical angle fifth-order, seventh-order, eleventh-order, and thirteenth-order components that distort the induced voltage that is the voltage between the terminals of the motor affect the sixth-order electrical angle and the 12th-order electrical angle in the q-axis component of torque. It is known.

  Therefore, if the torque ripple of both the electrical angle 6th order and electrical angle 12th order components, which are basic orders, can be reduced, a low noise low vibration motor, a low noise low vibration motor for EPS, a low cost low noise low vibration motor, A low noise low noise low vibration motor for EPS can be realized.

  The present invention has been made to solve the above problems, and its object is to drive a brushless motor and a brushless motor capable of reducing torque ripples of both the electrical angle 6th order and the electrical angle 12th order components. It is to provide a method.

  The invention according to claim 1 is a rotor in which magnetic poles are alternately arranged in P (an integer of 2 or more) circumferential directions, and s pieces in which two different m-phase windings are wound around the outer circumference of the rotor. A stator having a plurality of slots, wherein the stator has two different m-phase windings at electrical angles and a phase difference angle between adjacent slots ((360 × P) / (s × 2)) winding at the slot pitch and energizing at the phase difference angle, and setting the electrical angle between the stator and the rotor to be a magnetic skew twice as large as the phase difference angle between the slots. .

  According to the first aspect of the present invention, the phase difference angle between adjacent slots ((360 × P) / (s × 2)) of two different m-phase windings wound around the stator in electrical angle. The coil was wound at a slot pitch of 2 mm and energized (powered) at the phase difference angle. In this way, it is possible to eliminate the odd multiple component of the basic electrical angle sixth order component of the torque ripple generated in the brushless motor. In addition, since the magnetic angle between the stator and the rotor is set to be twice as large as the phase difference angle between the slots, the even number of the sixth-order component of the basic electrical angle of the torque ripple generated in the brushless motor. The double component (12th-order electrical angle component and multiple component thereof) can be eliminated.

According to a second aspect of the present invention, in the brushless motor according to the first aspect, the m-phase winding is a three-phase winding, and the phase difference angle is 30 degrees.
According to the invention of claim 2, the m-phase winding is a three-phase winding, the phase difference angle ((360 × P) / (s × 2)) is 30 degrees, and the magnetic skew is It will be 60 degrees. In other words, in this configuration, since the phase difference angle (360 × P) / (s × 2) = 30, the configuration is limited to P (number of magnetic poles) / s (number of slots) = 1/6. The effect of the invention of claim 1 can be obtained.

  The invention according to claim 3 is a brushless motor comprising a rotor in which magnetic poles are alternately arranged in a circumferential direction, and a stator having two different three-phase windings wound around the outer periphery of the rotor. The stator was set such that two different three-phase windings were wound at a slot pitch of 30 degrees in electrical angle, and a magnetic skew of 60 degrees in electrical angle was established between the stator and the rotor.

  According to the third aspect of the present invention, two different three-phase windings to be wound are wound around the stator at a slot pitch of 30 degrees in electrical angle. If two different three-phase windings are energized (powered) with a phase difference of 30 electrical angles, the torque ripple of the electrical angle 6th order component generated in the brushless motor can be eliminated. In addition, by setting the magnetic skew between the stator and the rotor to have an electrical angle of 60 degrees, the torque ripple of the 12th-order electrical angle component generated in the brushless motor can be eliminated.

  According to a fourth aspect of the present invention, in the brushless motor according to the third aspect, the stator includes a core having a plurality of teeth extending in the radial direction and provided at a constant pitch in the circumferential direction, and a three-phase winding mounted on the teeth. The winding of the stator includes a plurality of conductor portions that are axially penetrated through the slots between the teeth and are laminated in the radial direction, and between the adjacent conductor portions in the radial direction for each phase. It is an SC winding that is electrically connected by welding at the axially outer end on the core side and is connected in the circumferential direction. There are two SC windings of the same phase, and the power receiving terminals of each phase are the same. It was pulled out in the axial direction from the conductor part in the radial direction lamination position.

According to the fourth aspect of the present invention, it is possible to provide a motor that is small in the axial direction and has little torque ripple.
According to a fifth aspect of the present invention, in the brushless motor according to any one of the first to fourth aspects, the stator has a first conductor portion and a fourth conductor portion, and the first conductor portion and the first conductor portion. A four-conductor portion connected at the base end portion, and an outer conductor for wave winding, a second conductor portion and a third conductor portion, and the second conductor portion and the third conductor portion are connected at the base end portion; A segment composed of a lap winding inner conductor enclosed in a wave winding outer conductor, the first conductor portion and the second conductor portion, and the third conductor portion and the fourth conductor portion; Each set is inserted into each slot formed in an in-phase stator core adjacent to each other, and the first conductor portion from the first conductor portion to the fourth conductor portion is radially inserted into each slot. , The second conductor portion, the third conductor portion, and the fourth conductor portion arranged in this order and adjacent one slot The fourth conductor of the other slot adjacent to the tip of the third conductor of one of the adjacent slots is connected to the tip of the second conductor of the other adjacent slot connected to the tip of the first conductor A stator in which three-phase Y-connection windings made of SC windings are wound with a shift of one slot pitch by connecting the tip of each part.

  According to the fifth aspect of the present invention, since the two different three-phase windings wound around the stator are three-phase Y-connection windings each composed of an SC winding, the occupation ratio of the windings in the slot Thus, the output of the brushless motor can be increased, and the torque ripples of the electrical angle 6th order component and the electrical angle 12th order component generated in the brushless motor can be eliminated.

  According to a sixth aspect of the present invention, in the brushless motor according to any one of the first to fifth aspects, the rotor is set to have a magnetic skew with an electrical angle of 60 degrees with respect to the stator.

  According to the sixth aspect of the present invention, the torque ripple of the 12th-order electrical angle component generated in the brushless motor can be eliminated by causing the rotor to magnetically skew with an electrical angle of 60 degrees with respect to the stator.

  The invention according to claim 7 is the brushless motor according to claim 6, wherein the rotor is divided into a plurality of equal divisions in the axial direction, and the magnet is circumferentially arranged so that the number of pole pairs is 5 for each division. This is a ring magnet type rotor in which ten ring magnets provided at equal angular intervals are arranged.

  According to the seventh aspect of the present invention, the torque ripple of the 12th-order electrical angle component generated in the brushless motor is eliminated by causing the ring magnet type rotor to magnetically skew with an electrical angle of 60 degrees with respect to the stator. Can do.

  The invention described in claim 8 is the brushless motor according to claim 6, wherein the rotor is a continuous pole type rotor in which five magnets are provided in the circumferential direction so that the number of pole pairs is five.

  According to the eighth aspect of the present invention, the torque ripple of the twelfth electrical angle component generated in the brushless motor is eliminated by causing the continuous pole type rotor to magnetically skew with an electrical angle of 60 degrees with respect to the stator. be able to.

  According to a ninth aspect of the present invention, in the brushless motor according to the eighth aspect of the present invention, the continuous pole type rotor includes a rotor core composed of a divided rotor core formed by being divided into a plurality of parts in the axial direction.

  According to the ninth aspect of the present invention, the torque ripple of the 12th-order electrical angle component generated in the brushless motor is eliminated by causing the continuous pole type rotor to magnetically skew with an electrical angle of 60 degrees with respect to the stator. be able to.

  According to a tenth aspect of the present invention, in the brushless motor according to any one of the first to fifth aspects, the stator is set to have a magnetic skew with an electrical angle of 60 degrees with respect to the rotor.

  According to the tenth aspect of the present invention, the torque ripple of the 12th-order electrical angle component generated in the brushless motor can be eliminated by causing the stator to magnetically skew with an electrical angle of 60 degrees with respect to the rotor.

  The invention according to claim 11 is the brushless motor according to any one of claims 1 to 10, wherein the brushless motor has a rotating shaft connected to a speed reducer of the electric power steering device, and the speed reducer is interposed therebetween. The motor that drives the steering shaft.

  According to the eleventh aspect of the present invention, the brushless motor used in the electric power steering apparatus can eliminate the torque ripple of the electrical angle sixth-order component and the electrical angle twelfth-order component, thereby reducing noise and vibration. I get out.

  A twelfth aspect of the present invention is the brushless motor driving method according to any one of the first to eleventh aspects of the present invention, which is about 30 degrees with respect to two different three-phase windings wound around the stator. Energized with phase difference.

  According to the twelfth aspect of the present invention, the torque ripple of the electrical angle sixth-order component generated in the brushless motor is eliminated by energizing (feeding) two different three-phase windings with a phase difference of 30 electrical degrees. Can be made. Further, for example, by setting the magnetic skew between the stator and the rotor to have an electrical angle of 60 degrees, the torque ripple of the 12th-order electrical angle component generated in the brushless motor can be eliminated.

  According to the present invention, it is possible to reduce the torque ripple of both the electrical angle 6th order and the electrical angle 12th order components.

Sectional drawing of the brushless motor of 1st Embodiment. (A) is a front view of the stator core of 1st Embodiment, (b) is the sectional view on the aa line of FIG. 2 (a). The partial expanded view of the three-phase winding of 1st Embodiment. Similarly, a partial development view of a three-phase winding. The perspective view of the segment before slot insertion. The perspective view of the segment after slot insertion. The partial expanded view of the winding of U1 phase of the 1st system. Similarly, the partial expanded view of the winding of U1 phase of the 1st system. Sectional drawing which shows the state in which each conductor part of the segment was inserted in the slot. The electric circuit diagram of the 1st system 3 phase winding. The partial expanded view of the winding of U2 phase of the 2nd system. The partially expanded view of the winding of U2 phase of the 2nd system similarly. The electric circuit diagram of 2nd system | strain 3 phase winding. FIG. 2 is a perspective view of a continuous polo rotor core according to the first embodiment. The front view of the rotor of 2nd Embodiment. The front view of the rotor of 3rd Embodiment. (A) is a front view of the stator core of 4th Embodiment, (b) is the sectional view on the aa line of Fig.17 (a). The front view which shows the rotor of 4th Embodiment. The front view which similarly shows another rotor of 4th Embodiment. The perspective view of another rotor core of a 4th embodiment similarly. The perspective view of the continuous type rotor core which shows another example of a rotor. The front view seen from the axial direction for demonstrating a stator and a rotor.

(First embodiment)
A first embodiment in which the present invention is embodied in a brushless motor will be described below with reference to FIGS.

  As shown in FIG. 1, the motor case 2 of the brushless motor 1 has a yoke 3 formed in a bottomed cylindrical shape, and a front end plate 4 that closes an opening on the front side of the yoke 3. . A storage box 5 is attached to the outer side of the yoke 3 on the rear side.

  A stator 6 as an armature is fixed to the inner peripheral surface of the yoke 3. As shown in FIG. 2, the stator 6 is provided with a stator core 7 fixed on the inner surface of the yoke 3. As shown in FIG. 2A, the stator core 7 includes a cylindrical portion 8 and a plurality of teeth 9 extending radially inward from the cylindrical portion 8 and provided in the circumferential direction. As shown in FIG. 2B, the stator core 7 is formed by laminating a plurality of core pieces 7 a to form one stator core 7.

  In the present embodiment, 60 teeth 9 are formed. Accordingly, 60 slots S formed between the teeth 9 are formed, and the 60 teeth 9 are arranged and formed at equal angular intervals of 6 degrees as viewed from the central axis of the cylindrical portion 8. . For convenience of explanation, when individual slots S need to be individually identified, slot numbers “1” to “60” that are consecutive numbers in the circumferential direction of the 60 slots S will be described.

  As shown in FIGS. 3 and 4, in each slot S, a three-phase winding composed of a U phase, a V phase, and a W phase is wound. 3 and 4, slot numbers “1” to “60” of the slots S are given in the circumferential direction.

  A segment SG shown in FIG. 5 is inserted into each slot S from one side (rear side) in the axial direction toward the other side (front side). Then, by connecting the segments SG with each other according to a predetermined rule, a three-phase Y-connected SC winding is formed.

  As shown in FIG. 5, the segment SG before being inserted into the slot S has an outer conductor OS for wave winding and an inner conductor IS for lap winding. The outer conductor OS and the inner conductor IS are coated with an insulating material so that the outer conductor OS and the inner conductor IS are not electrically connected.

  The outer conductor OS has a first conductor part OSi and a fourth conductor part OSo, and the base end part of the first conductor part OSi and the base end part of the fourth conductor part OSo are connected by the connecting conductor part OSc. Yes. The first conductor portion OSi and the fourth conductor portion OSo are bent so as to expand in a direction away from the connecting conductor portion OSc, and then bent so as to be parallel to each other.

  The inner conductor IS is disposed so as to be surrounded by the outer conductor OS. The inner conductor IS has a second conductor portion ISi and a third conductor portion ISo, and the base end portion of the second conductor portion ISi and the base end portion of the third conductor portion ISo are connected by the connecting conductor portion ISc. Yes. The second conductor portion ISi is bent from the connecting conductor portion ISc along the first conductor portion OSi of the outer conductor OS. The third conductor part ISo is bent from the connecting conductor part ISc along the fourth conductor part OSo of the outer conductor OS.

  Then, the segment SG before being inserted into the slot S is formed by arranging the inner conductor IS inside the outer conductor OS. For the segment SG thus formed, the first and second conductor portions OSi, ISi of the outer and inner conductors OS, IS are inserted into the same slot S, and the fourth and third of the outer and inner conductors OS, IS are inserted. The conductor portions OSo and ISo are inserted into adjacent in-phase slots S different from the first and second conductor portions OSi and ISi.

  For example, when the first and second conductor portions OSi, ISi are inserted into the slot S with the slot number “60” for the outer and inner conductors OS, IS, the fourth and third conductor portions OSo, ISo are assigned with the slot number “6”. Is inserted into the slot S. That is, the first and second conductor portions OSi, ISi and the fourth and third conductor portions OSo, ISo of one segment SG are inserted with an interval of 6 slot pitches.

  In the slot S with the slot number “6” into which the fourth and third conductor portions OSo and ISo are inserted, the first and second conductor portions OSi and ISi of the outer and inner conductors OS and IS of the adjacent segment SG are provided. Inserted. Further, the adjacent segment SG inserts the fourth and third conductor portions OSo, ISo of its outer and inner conductors OS, IS into the slot S of the slot S number “12”.

  By sequentially inserting the segment SG into the slot S in the same manner, the first and second conductor portions OSi, ISi of the tenth segment SG are connected to the slot number “60”. It is inserted into the slot S and goes around once. A winding for one phase is formed by connecting the 10 rotated segments SG to each other.

  Therefore, since there are 60 slots S and 6-phase windings are formed, two U-phase, V-phase, and W-phase three-phase windings (the first three-phase winding and the second three-phase winding) Winding) will be formed. Here, when specifying and explaining the first system three-phase winding and the second system three-phase winding, respectively, the phases of the first system three-phase winding are U1, V1, and W1 phases, Each phase of the second system three-phase winding is referred to as a U2 phase, a V2 phase, and a W2 phase.

  Independent three-phase AC power is supplied to the first system three-phase winding and the second system three-phase winding. In the present embodiment, the three-phase alternating current supplied to (powered to) the first system three-phase winding and the three-phase alternating current supplied to the second system three-phase winding have a phase difference of 30 electrical angles. Yes.

  In this embodiment, the slots S used by the windings of each phase of the first system three-phase winding and the second system three-phase winding are assigned as shown in Table 1.

As is apparent from Table 1, the slot numbers of the U1 phase of the first system three-phase winding are “60”, “6”, “12”, “18”, “24”, “30”, “36”. , “42”, “48”, “54”, the winding is wound (segment SG is inserted).

  The V1 phase of the first system three-phase winding is wound in each slot S shifted by 2 slot pitches relative to the U1 phase winding of the first system three-phase winding (segment SG is inserted). ) In addition, the W1 phase of the first system three-phase winding is wound in each slot S shifted by 4 slot pitches relative to the U1 phase winding of the first system three-phase winding (segment SG is inserted). )

  By the way, the U2 phase of the second system three-phase winding is shifted by one slot pitch with respect to the U1 phase winding of the first system three-phase winding, and the slot numbers are “1”, “7”, “13”. ”,“ 19 ”,“ 25 ”,“ 31 ”,“ 37 ”,“ 43 ”,“ 49 ”,“ 55 ”, the winding is wound (segment SG is inserted).

  Similarly, the V2 phase of the second system three-phase winding is wound in each slot S shifted by 2 slot pitches relative to the U2 phase winding of the second system three-phase winding (segment SG is It can be seen that In addition, the W2 phase of the second system three-phase winding is wound in each slot S shifted by 4 slot pitches relative to the U2 phase winding of the second system three-phase winding (segment SG is inserted). )

  Then, the segment SG including the wave winding outer conductor OS and the lap winding inner conductor IS shown in FIG. 5 is inserted into all 60 slots S under the above conditions. Subsequently, as shown in FIG. 6, the outer conductor OS and the inner conductor IS are bent and formed for the segments SG of all the slots S to form the windings of the respective phases.

  The outer conductor OS for wave winding is bent in a direction in which the first conductor portion OSi and the fourth conductor portion OSo protruding from the slot S are separated from each other. And about the 1st and 4th conductor part OSi and OSo of the outer side conductor OS, the part which protruded from the slot S and was bent in the direction mutually spaced apart is called 1st and 4th welding part OWi and OWo.

On the other hand, the folding of the inner conductor IS for lap winding is performed by bending the second conductor portion ISi and the third conductor portion ISo of the portion protruding from the slot S so as to approach each other. And about the 2nd and 3rd conductor part ISi, ISo of the inner side conductor IS, the part which protruded from the slot S and was bent in the direction which mutually approaches is called 2nd and 3rd weld part IWi, IWo.
(First system three-phase winding)
Next, the first system three-phase winding will be described.

Here, a winding method of the U1-phase winding of the first system three-phase winding using the ten segments SG will be described with reference to FIGS.
Slots S having slot numbers shown in Table 1 are assigned to slots S used for the U1 phase winding of the first system, and ten segments SG1 to SG10 are used.

  Here, the first segment SG1 is inserted into slot S with slot numbers “60” and “6”. The second segment SG2 is inserted into slot S with slot numbers “6” and “12”. The third segment SG3 is inserted into slot S with slot numbers “12” and “18”. The fourth segment SG4 is inserted into slot S with slot numbers “18” and “24”. The fifth segment SG5 is inserted into slot S with slot numbers “24” and “30”.

  Further, the sixth segment SG6 is inserted into slot S with slot numbers “30” and “36”. The seventh segment SG7 is inserted into slot S with slot numbers “36” and “42”. The eighth segment SG8 is inserted into slot S with slot numbers “42” and “48”. The ninth segment SG9 is inserted into slot S with slot numbers “48” and “54”. The tenth segment SG10 is inserted into slot S with slot numbers “54” and “60”.

  When inserting the segments SG1 to SG10 into each slot S, the connecting conductor portion OSc of the outer conductor OS and the connecting conductor portion ISc of the inner conductor IS are inclined so that the subsequent segment can be easily inserted into the predetermined slot S. It is bent to be twisted and inserted.

  Now, in the slot numbers “60” and “6”, the first segment SG1 for the U1 phase is inserted. Accordingly, the second conductor portion ISi of the inner conductor IS and the first conductor portion OSi of the outer conductor OS are arranged in the slot S of the slot number “60”, and the inner conductor is inserted in the slot S of the slot number “6”. A third conductor portion ISo of IS and a fourth conductor portion OSo of the outer conductor OS are arranged.

  In the slot numbers “6” and “12”, the second segment SG2 for the U1 phase is inserted. Accordingly, the second conductor portion ISi of the inner conductor IS and the first conductor portion OSi of the outer conductor OS are arranged in the slot S of the slot number “6”, and the inner conductor is inserted in the slot S of the slot number “12”. A third conductor portion ISo of IS and a fourth conductor portion OSo of the outer conductor OS are arranged.

  At this time, in the slot S of the slot number “6”, the third and fourth conductor portions ISo and OSo of the inner and outer conductors IS and OS of the first segment SG1 are arranged, and the second segment SG2 The first and second conductor portions OSi, ISi of the outer and inner conductors OS, IS are arranged.

  That is, as shown in FIG. 9, the slot S has a four-layer structure in the order of the first conductor portion OSi, the second conductor portion ISi, the third conductor portion ISo, and the fourth conductor portion OSo from the inside in the radial direction. Has been placed. Then, the fourth welded portion OWo of the outer conductor OS (inserted through the slot number “6”) of the first segment SG1 and the inner conductor IS (slot number “12” of the second segment SG2 are inserted). The third welded portion IWo is welded.

An insulator 10 is formed on the inner peripheral surface of the slot S, and the segment SG and the stator core 7 of the stator 6 are electrically insulated.
In the slot numbers “12” and “18”, the third segment SG3 for the U1 phase is inserted. Accordingly, the second conductor portion ISi of the inner conductor IS and the first conductor portion OSi of the outer conductor OS are arranged in the slot S of the slot number “12”, and the inner conductor is inserted in the slot S of the slot number “18”. A third conductor portion ISo of IS and a fourth conductor portion OSo of the outer conductor OS are arranged.

  At this time, the third and fourth conductor portions ISo, OSo of the inner and outer conductors IS, OS of the second segment SG2 are arranged in the slot S of the slot number “12”, and the third segment SG3 The first and second conductor portions OSi, ISi of the outer and inner conductors OS, IS are arranged. Then, the fourth welded portion OWo of the outer conductor OS (inserted through the slot number “12”) of the second segment SG2 and the inner conductor IS (slot number “18” of the third segment SG3 are inserted). A) Welding the third welded part IWo of o.

  Furthermore, the second welded portion IWi of the inner conductor IS (inserted through the slot number “6”) of the second segment SG2 and the outer conductor OS (slot number “12” of the third segment SG3). The fourth welded portion OWo of (inserted) is welded. Thereafter, the U1-phase winding shown in FIGS. 7 and 8 is formed by repeating the same process for the similar 4 to 10 segments SG4 to SG10.

The other V1-phase and W1-phase windings of the first system three-phase winding are wound in the same manner as the U1-phase winding. Further, the first system three-phase winding is constituted by a three-phase Y connection. Therefore, the neutral point terminals T0u, T0v, T0w connected to the neutral point N1 (see FIG. 10) and the power receiving terminals T1u, T1v, T1w that receive power are determined for the windings of each phase.
(Setting of neutral point terminal and power receiving terminal)
As shown in FIGS. 7 and 3, in this embodiment, the outer conductor OS of the first segment SG1 and the connecting conductor portions OSc and ISc of the inner conductor IS are separated from each other in the U1-phase winding.

  Here, the separation end of the connection conductor portion OSc of the outer conductor OS and the connection end to the fourth conductor portion OSo of the outer conductor OS, and the separation end of the connection conductor portion ISc of the inner conductor IS and the same inner conductor IS. The one connected to the second conductor portion ISi is connected.

  The one that is connected to the first conductor portion OSi of the outer conductor OS and that is the separation end of the connecting conductor portion OSc of the outer conductor OS is defined as a neutral point terminal T0u of the U1 phase. On the other hand, the one connected to the third conductor portion ISo of the inner conductor IS and the separated end of the connecting conductor portion ISc of the inner conductor IS is defined as a U1-phase power receiving terminal T1u.

  That is, the neutral point terminal T0u is a terminal drawn out from the first conductor portion OSi of the outer conductor OS arranged on the innermost side in the radial direction in the slot S of the slot number “60”. The power receiving terminal T1u is a terminal drawn out from the third conductor portion ISo of the inner conductor IS disposed at the third outer position in the radial direction in the slot S of the slot number “6”.

Therefore, the power receiving terminal T1u is disposed outside the neutral point terminal T0u in the radial direction in the slot S.
Further, as shown in FIG. 3, for the V1 phase winding, the outer conductor OS of the segment SG and the connecting conductor portions OSc and ISc of the inner conductor IS inserted in the slot numbers “56” and “2” are separated.

  Similarly, the separated end of the connecting conductor portion OSc of the outer conductor OS and the fourth conductor portion OSo of the outer conductor OS, and the separated end of the connecting conductor portion ISc of the inner conductor IS and the inner conductor IS. The one connected to the second conductor portion ISi is connected.

  The one that is connected to the first conductor portion OSi of the outer conductor OS and that is the separation end of the connecting conductor portion OSc of the outer conductor OS is defined as a neutral point terminal T0v of the V1 phase. On the other hand, the one connected to the third conductor portion ISo of the inner conductor IS and the separated end of the connecting conductor portion ISc of the inner conductor IS is defined as a V1 phase power receiving terminal T1v.

  That is, the neutral point terminal T0v is a terminal drawn out from the first conductor portion OSi of the outer conductor OS arranged on the innermost side in the radial direction in the slot S of the slot number “56”. The power receiving terminal T1v is a terminal drawn from the third conductor portion ISo of the inner conductor IS arranged at the third outer position in the radial direction in the slot S of the slot number “2”.

Therefore, the power receiving terminal T1v is arranged outside in the radial direction in the slot S from the neutral point terminal T0v.
Further, as shown in FIG. 3, for the W1 phase winding, the outer conductor OS of the segment SG and the connecting conductor portions OSc and ISc of the inner conductor IS inserted in the slot numbers “52” and “58” are separated.

  Similarly, the separated end of the connecting conductor portion OSc of the outer conductor OS and the fourth conductor portion OSo of the outer conductor OS, and the separated end of the connecting conductor portion ISc of the inner conductor IS and the inner conductor IS. The one connected to the second conductor portion ISi is connected.

  The one that is connected to the first conductor part OSi of the outer conductor OS and that is the separation end of the connection conductor part OSc of the outer conductor OS is defined as a neutral point terminal T0w of the W1 phase. On the other hand, the W1 phase power receiving terminal T1w is the separation end of the connecting conductor portion ISc of the inner conductor IS and the one connected to the third conductor portion ISo of the inner conductor IS.

  That is, the neutral point terminal T0w is a terminal drawn out from the first conductor portion OSi of the outer conductor OS arranged on the innermost side in the radial direction in the slot S of the slot number “52”. The power receiving terminal T1w is a terminal drawn from the third conductor portion ISo of the inner conductor IS arranged at the third outer position in the radial direction in the slot S of the slot number “58”.

Therefore, the power receiving terminal T1w is disposed outside the neutral point terminal T0w in the radial direction in the slot S.
The neutral point terminals T0u, T0v, T0w and the power receiving terminals T1u, T1v, T1w may be formed by processing the segment SG as described above, or only for the corresponding part (the above-mentioned segment A segment (different from SG) may be inserted.

Then, if the neutral point terminals T0u, T0v, T0w of each phase are connected to each other by a neutral line L1n, and the power receiving terminals T1u, T1v, T1w of each phase are the receiving ends, the three-phase Y of the first system Wires for connection are formed, and an electric circuit as shown in FIG. 10 is formed. In the figure, “L1” indicates that the respective windings circulate from the power receiving terminals T1u, T1v, T1w, and the separation end of the connection conductor portion OSc of the outer conductor OS and the connection conductor portion ISc of the inner conductor IS are separated. Indicates the inductance to the connection point with the end. Also. “L2” is from the connection point between the separation end of the connection conductor portion OSc of the outer conductor OS and the separation end of the connection conductor portion ISc of the inner conductor IS to each neutral point terminal T0u, T0v, T0w. Indicates inductance.
(Second system, three-phase winding)
Next, the second system three-phase winding will be described.

  The second system three-phase winding is a three-phase Y-connection as in the first system three-phase winding. Then, each of the three-phase windings of the second system is wound around each of the slots S with a shift of one slot pitch from each of the corresponding three-phase windings of the first system.

Therefore, as shown in FIGS. 11 and 12, the U2 phase winding of the second system is wound around each slot S with a one-slot pitch shift with respect to the U1 phase winding of the first system.
Slots S having slot numbers shown in Table 1 are assigned to slots S used for the U2 phase winding of the second system, and ten segments SG1a to SG10a are used.

  Here, the first segment SG1a is inserted into the slot S with slot numbers “1” and “7”. The second segment SG2a is inserted into slot S with slot numbers “7” and “13”. The third segment SG3a is inserted into slot S with slot numbers “13” and “19”. The fourth segment SG4a is inserted into slot S with slot numbers “19” and “25”. The fifth segment SG5a is inserted into slot S with slot numbers “25” and “31”.

  Further, the sixth segment SG6a is inserted into the slot S with slot numbers “31” and “37”. The seventh segment SG7a is inserted into slot S with slot numbers “37” and “43”. The eighth segment SG8a is inserted into slot S with slot numbers “43” and “49”. The ninth segment SG9a is inserted into slot S with slot numbers “49” and “55”. The tenth segment SG10a is inserted into slot S with slot numbers “55” and “1”.

  Similarly to the U1 phase winding of the first system, the segments SG1a to SG10a are connected to form the U2 phase winding of the second system. The other V2-phase and W2-phase windings of the second system three-phase windings are also wound in the same manner as the U2-phase windings.

Further, the second system three-phase winding is similarly configured with a three-phase Y connection. Accordingly, the neutral point terminals T0ua, T0va, T0wa connected to the neutral point N2 (see FIG. 13) and the power receiving terminals T2u, T2v, T2w for receiving power are determined for the windings of each phase.
(Setting of neutral point terminal and power receiving terminal)
As shown in FIG. 3 and FIG. 4, in this embodiment, the neutral point terminal T0ua and the power receiving terminal T2u of the U2-phase winding are in relation to the neutral point terminal T0u and the power receiving terminal T1u of the U1 phase. Provided at positions that oppose each other by 180 degrees in the circumferential direction. Therefore, with respect to the U2-phase winding, the outer conductor OS of the fifth segment SG5a and the connecting conductor portions OSc and ISc of the inner conductor IS are separated.

  Here, as in the U1-phase winding, as shown in FIG. 12, the end connected to the fourth conductor portion OSo of the outer conductor OS and the separation conductor of the connecting conductor portion OSc of the outer conductor OS, and the inner conductor IS To the second conductor portion ISi of the inner conductor IS which is the separated end of the connecting conductor portion ISc.

  And the direction which is the separation end of the connection conductor part OSc of the outer conductor OS and is connected to the first conductor part OSi of the outer conductor OS is defined as a neutral point terminal T0ua of the U2 phase. On the other hand, the one connected to the third conductor portion ISo of the inner conductor IS and the separated end of the connecting conductor portion ISc of the inner conductor IS is defined as a U2-phase power receiving terminal T2u.

  That is, the neutral point terminal T0ua is a terminal drawn out from the first conductor portion OSi of the outer conductor OS arranged on the innermost side in the radial direction in the slot S of the slot number “25”. Further, the power receiving terminal T2u is a terminal drawn from the third conductor portion ISo of the inner conductor IS arranged third outside in the radial direction in the slot S of the slot number “31”.

  Therefore, the power receiving terminal T2u is arranged on the outer side in the radial direction in the slot S than the neutral point terminal T0ua. The U2-phase power receiving terminal T2u and the neutral point terminal T0ua are arranged at positions that oppose each other by 180 degrees in the circumferential direction of the stator core 7 with respect to the U1-phase power receiving terminal T1u and the neutral point terminal T0u. The

  Next, with respect to the V2-phase winding, the neutral point terminal T0va and the power receiving terminal T2v are provided at positions opposite to the V1 phase neutral point terminal T0v and the power receiving terminal T1v in the circumferential direction by 242 degrees. . Therefore, as shown in FIGS. 3 and 4, for the V2-phase winding, the outer conductor OS of the segment SG inserted in the slot numbers “33” and “39” and the connecting conductor portions OSc and ISc of the inner conductor IS are provided. To separate.

  Similarly, the separated end of the connecting conductor portion OSc of the outer conductor OS and the fourth conductor portion OSo of the outer conductor OS, and the separated end of the connecting conductor portion ISc of the inner conductor IS and the inner conductor IS. The one connected to the second conductor portion ISi is connected.

  Further, the V2 phase neutral point terminal T0va is the separation end of the connecting conductor portion OSc of the outer conductor OS and the one connected to the first conductor portion OSi of the outer conductor OS. On the other hand, the one connected to the third conductor portion ISo of the inner conductor IS and the separation end of the connecting conductor portion ISc of the inner conductor IS is defined as a V2-phase power receiving terminal T2v.

  That is, the neutral point terminal T0va is a terminal drawn out from the first conductor portion OSi of the outer conductor OS arranged on the innermost side in the radial direction in the slot S of the slot number “33”. The power receiving terminal T2v is a terminal drawn from the third conductor portion ISo of the inner conductor IS arranged at the third outer position in the radial direction in the slot S of the slot number “39”. Therefore, the power receiving terminal T2v is disposed outside the neutral point terminal T0va in the radial direction in the slot S.

  Next, with respect to the W2-phase winding, the neutral point terminal T0wa and the power receiving terminal T2w are provided at positions facing the neutral point terminal T0w and the power receiving terminal T1w in the circumferential direction by 138 degrees in the circumferential direction. . Therefore, as shown in FIGS. 3 and 4, for the W2-phase winding, the outer conductor OS of the segment SG inserted in the slot numbers “29” and “35” and the connecting conductor portions OSc and ISc of the inner conductor IS are provided. To separate.

  Similarly, the separated end of the connecting conductor portion OSc of the outer conductor OS and the fourth conductor portion OSo of the outer conductor OS, and the separated end of the connecting conductor portion ISc of the inner conductor IS and the inner conductor IS. The one connected to the second conductor portion ISi is connected.

  Further, the W2 phase neutral point terminal T0wa is connected to the first conductor portion OSi of the outer conductor OS, which is the separation end of the connecting conductor portion OSc of the outer conductor OS. On the other hand, the W2 phase power receiving terminal T2w is the separated end of the connecting conductor portion ISc of the inner conductor IS and connected to the third conductor portion ISo of the inner conductor IS.

  That is, the neutral point terminal T0wa is a terminal drawn out from the first conductor portion OSi of the outer conductor OS arranged on the innermost side in the radial direction in the slot S of the slot number “29”. The power receiving terminal T2w is a terminal drawn from the third conductor portion ISo of the inner conductor IS disposed at the third outer position in the radial direction in the slot S of the slot number “35”. Therefore, the power receiving terminal T2w is disposed outside the neutral point terminal T0wa in the radial direction in the slot S.

  The neutral point terminals T0ua, T0va, T0wa and the power receiving terminals T2u, T2v, T2w may be formed by processing the segment SG as described above. A segment (different from SG) may be inserted.

  Then, if the neutral point terminals T0ua, T0va, T0wa of each phase are connected to each other by a neutral line L2n and the power receiving terminals T2u, T2v, T2w of each phase are drawn out, the winding of the three-phase Y-connection of the second system A line is formed, and an electric circuit as shown in FIG. 13 is formed. In the drawing, “L1” indicates that the respective windings circulate from the power receiving terminals T2u, T2v, and T2w, and the separation end of the connection conductor portion OSc of the outer conductor OS and the connection conductor portion ISc of the inner conductor IS are separated. Indicates the inductance to the connection point with the end. Also. “L2” is from the connection point between the separation end of the connection conductor portion OSc of the outer conductor OS and the separation end of the connection conductor portion ISc of the inner conductor IS to each neutral point terminal T0ua, T0va, T0wa. Indicates inductance.

  As shown in FIG. 1, the rotor 11 is disposed inside the stator 6 around which the first system three-phase winding and the second system three-phase winding are wound. The rotor 11 has a rotation shaft 12, and the rotation shaft 12 is rotatably supported by bearings 14 and 15 provided on the bottom of the yoke 3 and the front end plate 4.

  Further, as shown in FIG. 14, a rotor core 16 having a consequent pole structure is externally fitted to the rotating shaft 12 of the rotor 11. The rotor core 16 is equally divided into two in the axial direction, and the divided rotor cores 16a and 16b are divided between the adjacent divided rotor cores 16a and 16b by a predetermined shift angle θ1 with the central axis of the rotary shaft 12 as the rotation center. It is only shifted in one direction.

  On the outer peripheral surface of each of the divided rotor cores 16a and 16b, five magnets MG and five projecting magnetic pole portions formed on the rotor core 16 so as to face the stator 6, specifically the radially inner end of the teeth 9, respectively. 18 are provided alternately at an equiangular pitch in the circumferential direction.

  The five magnets MG are arranged with respect to the rotor core 16 such that the N poles are arranged on the inner side and the S poles are arranged on the outer side in the radial direction so that the five magnetic pole portions 18 become the N poles. Therefore, as shown in FIG. 14, N poles and S poles are alternately arranged in the circumferential direction, and the number of pole pairs of the rotor 11 is set to 5 (the number of magnetic poles (P) is 10).

  Therefore, since the number of pole pairs of the rotor 11 is 5 and 60 teeth 9 are provided, the pitch between the adjacent teeth 9 and the teeth 9 is 6 degrees in mechanical angle, so it is converted into an electrical angle. Then it becomes 30 degrees.

  As shown in FIG. 14, the divided rotor cores 16 a and 16 b are shifted in one direction by a predetermined shift angle θ1 with the central axis of the rotary shaft 12 as the rotation center, respectively, so that the divided rotor cores 16 a and 16 b as a whole are between the magnetic poles (tooth 9) of the stator 6. Thus, a magnetic skew with an electrical angle of 60 degrees is provided. By giving the magnetic skew of the electrical angle of 60 degrees, the torque ripple wave of the 12th-order electrical angle component is reduced.

Here, the shift angle θ1 (mechanical angle) for shifting between the adjacent divided rotor cores 16a and 16b is obtained by the following equation.
θ1 × number of divisions = 360 (degrees) / (12 (next) × number of pole pairs)
And because the number of pole pairs is 5,
θ1 × number of divisions = 360/60 = 6 degrees Therefore
Here, since the rotor core 16 shown in FIG. 14 has two divided rotor cores 16a and 16b, the shift angle (mechanical angle) θ1 is 3 degrees.

As a result, a magnetic skew with an electrical angle of 60 degrees is maintained between the magnetic poles of the rotor core 16 and the magnetic poles (teeth 9) of the stator 6.
A drive device 20 is housed in the housing box 5 fixed on the rear side outside of the yoke 3. The circuit board 21 of the driving device 20 includes a rotation sensor 22 for controlling the rotation of the rotor 11, an ECU (electronic control unit) 23, first switching transistors Q1u, Q1v, Q1w, second switching transistors Q2u, Q2v, Q2w, and the like. Various circuit elements are mounted.

  The rotation sensor 22 is mounted on the circuit board 21 so as to oppose the rotation shaft 12 that protrudes outward in the axial direction from the bottom of the yoke 3. The rotation sensor 22 is a Hall IC in this embodiment, and detects the rotation angle of the detection magnet 22a that rotates integrally with the rotation sensor 22 fixed to the shaft end surface of the rotation shaft 12.

  The ECU (electronic control unit) 23 has a microcomputer. Based on the detection signal from the rotation sensor 22, the ECU 23 detects the rotation angle, rotation speed, and the like of the brushless motor 1 at that time. Then, the ECU 23 calculates power supply timing to each phase of the first system three-phase winding and the second system three-phase winding. That is, the ECU 23 supplies the three-phase alternating current supplied to the second system three-phase winding with the phase difference of 30 electrical angles to the three-phase alternating current supplied to the first system three-phase winding.

  The first switching transistors Q1u, Q1v, and Q1w are, for example, power MOS transistors, and are on / off controlled based on a control signal from the ECU 23. The first switching transistors Q1u, Q1v, and Q1w are controlled to supply power to each phase of the first system three-phase winding via the lead lines L1u, L1v, and L1w by being turned on and off at a predetermined timing. To do. As a result, a rotating magnetic field generated by the first system three-phase winding is generated in the stator 6.

  The second switching transistors Q2u, Q2v, Q2w are made of, for example, power MOS transistors, and are on / off controlled based on a control signal from the ECU 23. The second switching transistors Q2u, Q2v, Q2w are controlled to supply power to each phase of the second-phase three-phase winding via the lead lines L2u, L2v, L2w by being turned on / off at a predetermined timing. To do. Thereby, a rotating magnetic field by the second system three-phase winding is generated in the stator 6.

  The brushless motor 1 according to the present embodiment is an EPS motor used in an electric power steering device (EPS), and a rotating shaft 12 of the rotor 11 is connected to a reduction gear (not shown), and the reduction gear is interposed through the reduction gear. And connected to a counterpart shaft such as a steering shaft (not shown) as a driven portion to drive the counterpart shaft such as the steering shaft.

Here, the above-described embodiment is set so as to satisfy the following formula and the like.
That is, the stator 6 has two different m-phase (three-phase in the present embodiment) windings as electrical angles, and a phase difference angle between adjacent slots S (360 × P) / (s × 2) (however, , P is the number of magnetic poles, and s is wound at a slot pitch of the number of slots S), and is set to be energized at the phase difference angle. Specifically, in the present embodiment, the phase difference angle is (360 × 10) / (60 × 2) = 30 degrees.

  In addition, in this embodiment, the magnetic skew between the stator 6 and the rotor 11 is 60 degrees in electrical angle so that the electrical angle is twice as much as the phase difference angle (30 degrees) between the slots S. Is set to

Next, the operation of the brushless motor 1 configured as described above will be described below.
Now, the ECU 23 controls supply of three-phase AC power to the first system three-phase winding. In addition, the ECU 23 supplies the three-phase AC power supplied to the second system three-phase winding to the three-phase AC power supplied to the first system three-phase winding with a phase difference of 30 electrical degrees.

At this time, the torque ripple wave of the electrical angle 6th order component and the torque angle wave of the electrical angle 12th order component generated in the three-phase windings of the first and second systems of the brushless motor 1 are generated.
Both torque ripple waves of the electrical angle 6th order component have a period of 60 degrees (= 360 degrees (electrical angle) / 6th order).

  In this case, since the slot S of the three-phase windings of the first and second systems is shifted by 30 degrees, which is half of that, it is generated by the adjacent first-system three-phase winding and second-system three-phase winding. Each torque ripple wave is vertically symmetric. Therefore, the ripple waves of the sixth-order components of both electrical angles are canceled out. As a result, the torque ripple of the electrical angle 6th order component generated in the brushless motor 1 disappears.

  On the other hand, the rotor core 16 having a consequent pole structure is divided into two equal parts in the axial direction to form divided rotor cores 16a and 16b. Then, the central axis of the rotary shaft 12 is set between the divided rotor cores 16a and 16b so that a magnetic skew of an electrical angle of 60 degrees is maintained between the magnetic poles of the rotor core 16 and the magnetic poles of the stator 6 (tooth 9). The rotation angle is shifted in one direction by a predetermined mechanical angle of 3 degrees.

As a result, the torque ripple wave of the 12th-order electrical angle component generated in the brushless motor 1 can be eliminated.
Next, characteristic effects of the above embodiment will be described below.

  (1) According to the present embodiment, 60 slots S are formed in the stator core 7 of the stator 6 and 60 teeth 9 are provided. Then, the first system three-phase winding and the second system three-phase winding were wound around 60 teeth 9. At this time, the three-phase windings of the second system were wound around the slots S by shifting one slot pitch with respect to the three-phase windings of the first system.

Then, the three-phase alternating current fed to the second system three-phase winding is fed with a phase difference of 30 electrical degrees with respect to the three-phase alternating current fed to the first system three-phase winding.
The torque ripple wave of the sixth component of the electrical angle generated in the first and second three-phase windings of the brushless motor 1 is 30 degrees, which is half the slot S of the first and second three-phase windings. (Electrical angle) is offset by the deviation. As a result, an odd multiple component (sixth-order component and 18th-order component) of a sixth-order electrical angle component that is a basic electrical angle component (= m-phase winding AC drive × 2 = 3 × 2 = 6) of torque ripple generated in the brushless motor 1. Secondary components, 30th component, etc.) can be eliminated.

  (2) According to this embodiment, the rotor core 16 is equally divided into two in the axial direction to form the divided rotor cores 16a and 16b. Then, the central axis of the rotary shaft 12 is set between the divided rotor cores 16a and 16b so that a magnetic skew of an electrical angle of 60 degrees is maintained between the magnetic poles of the rotor core 16 and the magnetic poles of the stator 6 (tooth 9). It was arranged so as to be shifted in one direction by a mechanical angle of 3 degrees to the center of rotation.

  Therefore, an even multiple component (12th order component and 24th order component) of the electrical angle 6th order component which is the basic electrical angle component (= m phase winding AC drive × 2 = 3 × 2 = 6) of the torque ripple generated in the brushless motor 1. Components, 36th order components, ie, multiple order components of the 12th order component) can be eliminated.

(3) According to the present embodiment, the torque ripple wave of the electrical angle 6th order component and the torque ripple wave of the electrical angle 12th order component are eliminated, so that the noise and vibration of the motor can be reduced. When the brushless motor 1 is used as an EPS motor, it is driven with low noise and vibration, so that a comfortable steering operation can be performed.
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.

  In the present embodiment, the rotor of the first embodiment is a continuous pole type rotor, but the present embodiment is different in that it is a ring magnet type rotor. Therefore, for convenience of explanation, the characteristic part will be described in detail and common parts will be omitted.

  As shown in FIG. 15, the rotor 30 divides the outer peripheral surface 31a of the rotor core 31 into three equal parts in the axial direction to form three ring magnets 32a, 32b, and 32c. Then, each of the divided ring magnets 32a, 32b, and 32c has 10 magnets MG attached in the circumferential direction. The ten magnets MG are attached to the rotor core 31 such that N poles and S poles are arranged in the radial direction, and magnets MG adjacent in the circumferential direction are different magnetic poles.

  As shown in FIG. 15, with respect to the ring magnets 32 a, 32 b, and 32 c configured in this manner, a magnetic skew with an electrical angle of 60 degrees is generated between the magnetic pole of the rotor core 31 and the magnetic pole (tooth 9) of the stator 6. As is maintained, the adjacent ring magnets 32a, 32b, 32c are shifted in one direction by a predetermined shift angle θ2 with the central axis of the rotary shaft 12 as the center of rotation.

  In this case, the N poles and the S poles are alternately arranged in the circumferential direction, and the number of pole pairs of the rotor 11 is five, and 60 teeth 9 are provided. Since the pitch is 6 degrees in mechanical angle, it becomes 30 degrees when converted to electrical angle.

  Incidentally, the shift angle θ2 of the ring magnets 32a, 32b, and 32c is an angle for giving a magnetic skew of an electrical angle of 60 degrees between the magnetic pole of the rotor core 31 and the magnetic pole of the stator 6 (tooth 9).

Here, the shift angle θ2 (mechanical angle) for shifting between the adjacent ring magnets 32a, 32b, 32c is obtained by the following equation.
θ2 × number of ring magnets = 360 (degrees) / (12 (next) × number of pole pairs) = 360/60 = 6 degrees And since the number of pole pairs is 5,
θ2 × number of ring magnets = 360/60 = 6 degrees
θ2 = 6 degrees / number of ring magnets Since the rotor core 31 shown in FIG. 15 has three ring magnets, the angle (mechanical angle) θ2 is 2 degrees mechanical angle. As a result, a magnetic skew with an electrical angle of 60 degrees is maintained between the magnetic poles of the rotor 30 and the magnetic poles of the stator 6 (tooth 9).

Even in this case, the torque ripple wave of both the electrical angle 6th order and the electrical angle 12th order components can be reduced. And the same effect described by (1) (2) (3) of 1st Embodiment can be acquired.
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG.

This embodiment is characterized in that it is different from the rotors of the first and second embodiments. Therefore, for convenience of explanation, the characteristic part will be described in detail and common parts will be omitted.
As shown in FIG. 16, a rotor core 41 is fitted on the rotary shaft 12 of the rotor 40. A plurality of magnets MG are provided on the outer peripheral surface 41 a of the rotor core 41 at equal angular intervals in the circumferential direction so as to face the stator 6, specifically, the radially inner end of the teeth 9. Ten magnets MG of this embodiment are attached. The ten magnets MG are attached to the rotor core 41 such that the N poles and the S poles are arranged in the radial direction, and the magnets MG adjacent in the circumferential direction are different magnetic poles. S poles are alternately arranged in the circumferential direction, and the number of pole pairs of the rotor 40 is set to five.

  As shown in FIG. 16, each magnet MG provided on the outer peripheral surface 41 a of the rotor core 41 is inclined (skewed) by a predetermined angle θ3 with respect to the axial direction of the rotating shaft 12.

  In this case, the N poles and the S poles are alternately arranged in the circumferential direction, and the number of pole pairs of the rotor 40 is five and 60 teeth 9 are provided. Since the pitch is 6 degrees in mechanical angle, it becomes 30 degrees when converted to electrical angle.

  Incidentally, the skew angle θ3 of each magnet MG is an angle for giving a magnetic skew of an electrical angle of 60 degrees between the magnetic pole of the rotor core 41 and the magnetic pole of the stator 6 (tooth 9).

Here, the skew angle θ3 (mechanical angle) of each magnet MG is obtained by the following equation.
θ3 = 360 (degrees) / (12 (next) × number of pole pairs) = 360/60 = 6 degrees Here, since the rotor 40 shown in FIG. 16 has five pole pairs, the angle (mechanical angle) θ3 is It will be 6 degrees. As a result, a magnetic skew with an electrical angle of 60 degrees is maintained between the magnetic poles of the rotor 40 and the magnetic poles of the stator 6 (tooth 9).

Even in this case, the torque ripple wave of both the electrical angle 6th order and the electrical angle 12th order components can be reduced. And the same effect described by (1) (2) (3) of 1st Embodiment can be acquired.
(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, unlike the first to third embodiments, the stator has a feature. Therefore, for convenience of explanation, the characteristic part of the stator and the associated rotor will be described in detail, and common parts will be omitted.

  As shown in FIGS. 17 (a) and 17 (b), with respect to the stator 6 shown in FIGS. 2 (a) and 2 (b), the teeth 9 formed on the stator core 7 are moved by a predetermined angle θ4 with respect to the axial direction of the rotary shaft 12. It is inclined (skew).

  On the other hand, the rotor 50, 60, 70 shown in FIG. 18, FIG. 19, FIG. Incidentally, the rotor 50 in FIG. 18 is attached at equal angular intervals in the circumferential direction without skewing the ten magnets MG on the outer peripheral surface 51a of the rotor core 51 attached to the rotating shaft 12. The ten magnets MG are attached to the rotor core 51 such that N poles and S poles are arranged in the radial direction, and magnets MG adjacent in the circumferential direction are different magnetic poles.

  19 is a ring magnet type rotor 60 in which the outer peripheral surface 61a of the rotor core 61 is divided into three equal parts in the axial direction on the rotary shaft 12, and three ring magnets 62a, 62b, 62c are formed. It is. And between each ring magnet 62a, 62b, 62c, it is comprised so that the center axis line of the rotating shaft 12 may not be shifted to a rotation center, respectively. In each of the divided ring magnets 62a, 62b, and 62c, ten magnets MG are attached in the circumferential direction. The ten magnets MG are attached to the rotor core 61 such that N poles and S poles are arranged in the radial direction, and magnets MG adjacent in the circumferential direction are different magnetic poles.

Furthermore, the rotor 70 of FIG. 20 is a continuous pole type rotor in which the rotor core 71 is not divided into the axial direction in the rotating shaft 12.
On the outer peripheral surface of the rotor core 71, five magnets MG and five magnetic pole portions 18 are alternately arranged at equal angular intervals in the circumferential direction so as to face the stator 6, specifically, the radially inner end of the teeth 9. Is provided.

  The five magnets MG are arranged with respect to the rotor core 71 such that the N poles are arranged on the inner side and the S poles are arranged on the outer side in the radial direction so that the five magnetic pole portions 18 become the N poles. Therefore, as shown in FIG. 20, N poles and S poles are alternately arranged in the circumferential direction, and the number of pole pairs of the rotor 11 is set to five.

  Accordingly, each of the rotors 50, 60, and 70 shown in FIGS. 18, 19, and 20 has a pole pair number of 5, so the electrical angle is 30 degrees, which corresponds to a mechanical angle of 6 degrees. To do. As a result, the interval between the adjacent teeth 9 of the stator core 7 and the teeth 9 is 6 degrees in terms of mechanical angle, so that it becomes 30 degrees when converted to an electrical angle.

  Incidentally, the skew angle θ4 of the teeth 9 formed on the stator core 7 is an angle for giving a magnetic skew of an electrical angle of 60 degrees between the magnetic poles of the rotors 50, 60, and 70 and the magnetic pole of the stator 6 (tooth 9). is there.

Here, the skew angle θ4 of the teeth 9 is obtained by the following equation.
θ4 = 360 (degrees) / (12 (next) × number of pole pairs)
Here, since the number of pole pairs of each of the rotors 50, 60, and 70 shown in FIGS. 18 to 20 is 5, θ4 is 6 degrees.

  Even in this case, the torque ripple wave of both the electrical angle 6th order and the electrical angle 12th order components can be reduced. And the same effect described by (1) (2) (3) of 1st Embodiment can be acquired.

The above embodiment may be modified as follows.
In the first embodiment, the rotor core 16 is equally divided into two in the axial direction to form the divided rotor cores 16a and 16b. Then, the central axis of the rotary shaft 12 is set between the divided rotor cores 16a and 16b so that a magnetic skew of an electrical angle of 60 degrees is maintained between the magnetic poles of the rotor core 16 and the magnetic poles of the stator 6 (tooth 9). The rotation center is arranged so as to be shifted in one direction by a predetermined 6 degrees.

  Without dividing this, for example, the consequent pole type rotor 70 shown in FIG. 20 is changed to a rotor 80 shown in FIG. 21, and the rotor 40 shown in FIG. The magnet MG disposed on the rotor core 81 and the protruding magnetic pole portion 18 formed on the rotor core 81 may be inclined (skewed) by a predetermined angle θ3. Also in this case, torque ripple waves of both the electrical angle 6th order and the electrical angle 12th order components can be reduced.

  Incidentally, in the motor of these continuous pole type rotors, as shown in FIG. 22, a continuous rotor 80 (70) in which magnetic poles of 2 × p poles (where “p” is the number of pole pairs) are arranged in the circumferential direction. ), And the number of teeth 9 (slots S) “Z (s)” is “2 × p × m × n (number) ) "(Where" m "is the number of phases of the stator winding and" n "is a natural number) and the stator 6 having a multi-phase winding wound around the slot S.

Incidentally, in the case shown in FIG. 22, based on this mathematical formula, the number “Z” of teeth 9 is
Z = 2 × 5 (number of magnets MG) × 3 (number of phases) × 2 = 60.

  Further, the rotor core 81 (71) of the continuous rotor 80 (70) is formed by laminating rotor core pieces made of steel plates in the same manner as the stator core 7. The rotor core 81 (71) is formed with a gap 90 (small magnetic lightweight portion) having a smaller specific gravity and magnetism than the rotor core piece at a radial position.

  As a result, in the continuous rotor 80 (70) in which magnetism easily moves in the rotor core 81 (71), in addition to the eddy current suppression effect due to the magnetic movement suppression effect of the gap 90 (small magnetic lightweight part), the rotor core piece By stacking a plurality of layers, generation of eddy current is further suppressed.

In the first embodiment, the rotor core 16 is divided into two, but the number of division may be three or more.
In the second embodiment, the number of ring magnets is three, but is not limited to this, and may be two, four, or more.

  In the fourth embodiment, the entire core piece 7a constituting the stator core 7 is continuously shifted about the rotation shaft 12 as the rotation center. However, only the portion constituting the tooth 9 of each core piece 7a is moved to the rotation shaft 12. May be carried out by continuously shifting around the rotation center. Alternatively, a plurality of core pieces 7a may be combined into one set, and only the portions constituting the teeth 9 of the core pieces 7a may be continuously shifted about the rotation shaft 12 as the rotation center.

In the first to fourth embodiments, the invention is embodied in the SPM (Surface Permanent Magnet Motor) type brushless motor, but may be applied to an IPM (Interior Permanent magnet Motor) type brushless motor.

  In the first to fourth embodiments, the brushless motor 1 is an EPS motor used in an electric power steering device (EPS), but other motors such as a power window motor, a wiper driving motor, etc. You may apply.

  In the above embodiment, the power receiving terminal and the neutral point terminal are separated by the connecting conductor portion OSc of the outer conductor OS for wave winding and the connecting conductor portion ISc of the inner conductor IS for lap winding, respectively. One side is electrically connected to the separation end connected to the fourth conductor portion OSo of the outer conductor OS and the separation end connected to the second conductor portion ISi of the inner conductor IS, and the other side is used without using the other side. A first one-side segment having the same configuration as that of the other separated conductor IS and integrally formed with a lead portion extending in the axial direction connected to the third conductor portion ISo is used as the lead portion for the power of each phase. The power receiving terminal is a second one-side segment that is the same form as the other separated outer conductor OS, and is formed integrally with a lead portion extending in the axial direction connected to the first conductor portion OSi. It may be used as each phase of the neutral point terminal and portions.

  In the above embodiment, for the SC winding, the wave winding outer conductor OS and the lap winding inner conductor IS are alternately connected in the circumferential direction, but only the wave winding inner conductor IS. May be connected in the circumferential direction, or only the outer conductor OS for lap winding may be connected in the circumferential direction.

  As in the above embodiment, each value or the like may be changed so as to satisfy the following formula or the like. That is, the stator has two different m-phase windings as electrical angles and a phase difference angle between adjacent slots S (360 × P) / (s × 2) (where P is the number of magnetic poles and s is a slot The number of S) is wound at a slot pitch and energized at the phase difference angle, and the stator and the rotor are appropriately changed so that the magnetic skew between the stator and the rotor is double the phase difference angle between the slots S. May be.

  For example, in the case of a three-phase winding (m = 3), the number of slots S is 48 (s = 48), and the number of magnetic poles is 8 (P = 8), the phase difference angle is 30 degrees (electrical The magnetic skew may be set to 60 degrees.

  For example, in the case of a four-phase winding (m = 4), the number of slots S is 80 (s = 80), and the number of magnetic poles is 10 (P = 10), the phase difference angle is 22.2. What is necessary is just to set so that it may become 5 degree | times (magnetic skew of an electrical angle of 45 degree | times).

  DESCRIPTION OF SYMBOLS 1 ... Brushless motor (motor), 2 ... Motor case, 3 ... Yoke, 4 ... Front end plate, 5 ... Housing box, 6 ... Stator, 7 ... Stator core, 7a ... Core piece, 8 ... Cylindrical part, 9 ... Teeth, DESCRIPTION OF SYMBOLS 10 ... Insulator, 11 ... Rotor, 12 ... Rotary shaft, 14, 15 ... Bearing, 16 ... Rotor core, 18 ... Magnetic pole part, 20 ... Drive apparatus, 21 ... Circuit board, 22 ... Rotation sensor, 22a ... Detection magnet, 23 ... ECU (electronic control unit), 24, 25 ... insertion hole, 30, 40, 50, 60, 70 ... rotor, 90 ... air gap, 31, 41, 51, 61, 71, 81 ... rotor core, 31a, 41a, 51a , 61a ... outer peripheral surface, 32a, 32b, 32c ... ring magnet, S ... slot, IS ... inner conductor, MG ... magnet, N1, N2 ... neutral point, OS ... outside Conductor, SG ... segment, ISc, OSc ... connection conductor, ISi ... second conductor (conductor), ISo ... third conductor (conductor), IWi ... second weld, IWo ... third weld, L1n, L2n ... neutral wire, L1u, L1v, L1w, L2u, L2v, L2w ... leader line, O1u, O1v, O1w, O2u, O2v, O2w ... output terminal, OSi ... first conductor part (conductor part), OSo ... 4th conductor part (conductor part), OWi ... 1st welding part, OWo ... 4th welding part, Q1u, Q1v, Q1w ... 1st switching transistor, Q2u, Q2v, Q2w ... 2nd switching transistor, SG1-SG10, SG1a to SG10a ... segment, T0u, T0v, T0w, T0ua, T0va, T0wa ... neutral point terminals, T1u, T1v, T1w, T2u, T2v, T2w ... Force receiving terminal.

Claims (12)

A rotor in which magnetic poles are alternately arranged in P (an integer of 2 or more) circumferential directions, and a stator having s slots around which two different m-phase windings are wound on the outer circumference of the rotor. A brushless motor,
The stator is wound with two different m-phase windings at an electrical angle and a slot pitch of a phase difference angle between adjacent slots ((360 × P) / (s × 2)) at the phase difference angle. A brushless motor that is energized and has a magnetic skew between the stator and the rotor that is twice the phase difference angle between the slots in terms of electrical angle. The brushless motor according to claim 1,
The m-phase winding is a three-phase winding, and the phase difference angle is 30 degrees. A brushless motor comprising a rotor in which magnetic poles are alternately arranged in the circumferential direction, and a stator in which two different three-phase windings are wound around the outer periphery of the rotor,
The stator is configured such that two different three-phase windings are wound at a slot pitch of 30 degrees in electrical angle, and a magnetic skew of 60 degrees in electrical angle is set between the stator and the rotor. Features a brushless motor. The brushless motor according to claim 3,
The stator has a core having a plurality of teeth extending in the radial direction and provided at a constant pitch in the circumferential direction and a three-phase winding mounted on the teeth.
The winding of the stator is composed of a plurality of conductor portions that are axially penetrated through the slots between the teeth and stacked in a radial direction, and the core side gap between the radially adjacent conductor portions for each phase. SC winding that is electrically connected by welding at the outer end in the axial direction and is connected in the circumferential direction.
A brushless motor characterized in that there are two SC windings of the same phase, and the power receiving terminals of each phase are drawn in the axial direction from the conductor portions at the same radial stack position. In the brushless motor according to any one of claims 1 to 4,
The stator includes a first conductor portion and a fourth conductor portion, and an outer conductor for wave winding in which the first conductor portion and the fourth conductor portion are connected at a base end portion, a second conductor portion, and a third conductor portion. A segment having a conductor portion, the second conductor portion and the third conductor portion being connected at a base end portion, and an inner conductor for overlapping winding enclosed in the outer conductor for wave winding; One conductor part and the second conductor part, and the third conductor part and the fourth conductor part are each set, and each set is inserted into each slot formed in an in-phase stator core adjacent to each other, In each slot, the first conductor portion to the fourth conductor portion are arranged in the order of the first conductor portion, the second conductor portion, the third conductor portion, and the fourth conductor portion from the inside in the radial direction,
The other end adjacent to the tip end of the third conductor portion of one adjacent slot is connected to the tip end portion of the first conductor portion of one adjacent slot and the tip end portion of the second conductor portion of the other adjacent slot. A brushless motor characterized by being a stator in which three-phase Y-connection windings composed of SC windings are wound with a one-slot pitch shift by connecting the tip end portion of the fourth conductor portion of each slot . In the brushless motor according to any one of claims 1 to 5,
The brushless motor is characterized in that the rotor is set so as to have a magnetic skew of an electrical angle of 60 degrees with respect to the stator. The brushless motor according to claim 6,
The rotor is divided into a plurality of equal divisions in the axial direction, and for each division, a ring magnet type in which 10 ring magnets are arranged at equal angular intervals in the circumferential direction so that the number of pole pairs is five. Brushless motor characterized by being a rotor of the above. The brushless motor according to claim 6,
The rotor is a continuous pole type rotor in which five magnets are provided in the circumferential direction so that the number of pole pairs is five. The brushless motor according to claim 8,
The continuous pole type rotor includes a rotor core composed of a divided rotor core formed by dividing the rotor in the axial direction. In the brushless motor according to any one of claims 1 to 5,
The brushless motor according to claim 1, wherein the stator is set to have a magnetic skew with an electrical angle of 60 degrees with respect to the rotor. The brushless motor according to any one of claims 1 to 10,
The brushless motor is a motor whose rotating shaft is connected to a speed reducer of an electric power steering apparatus and drives a steering shaft via the speed reducer. It is a drive method of the brushless motor given in any 1 paragraph of Claims 1-11,
A method of driving a brushless motor, wherein two different three-phase windings wound around a stator are energized with a phase difference of 30 degrees.