JP2018042437A - motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor capable of reducing thrust force.SOLUTION: A stator of a motor is configured by juxtaposing in an axial direction A-phase and B-phase stator parts 21 and 22 each having a configuration in which a coil 25 is arranged between a first stator core 23 and a second stator core 24 that have a plurality of claw-like magnetic poles 27 and 28, respectively. A rotor has four permanent magnets opposed to the claw-like magnetic poles 27 and 28 of the A-phase and B-phase stator parts 21 and 22 and juxtaposed in the axial direction. Magnetic force of an A-phase second magnet 14b and a B-phase first magnet 15a at an axial inside part that is a boundary side of each of the stator parts 21, 22, of the four permanent magnets, is set to be relatively weaker than magnetic force of an A-phase first magnet 14a and a B-phase second magnet 15b at an axial outside part that is an axial opposite side to the boundary part.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a motor.

  Conventionally, for example, as shown in Patent Document 1, a stator having a plurality of stator portions arranged in parallel in the axial direction with a predetermined electrical angle shifted, and a rotor having a permanent magnet facing the stator in the radial direction as a magnetic pole are provided. Motors are known. Each stator part uses a pair of annular stator cores having a plurality of claw-shaped magnetic poles in the circumferential direction, and the claw-shaped magnetic poles of the pair of stator cores are combined so that they are alternately arranged in the circumferential direction. Coils are arranged between the directions so that the claw-shaped magnetic poles function as different magnetic poles.

JP2013-158072A

  By the way, in order to reduce the vibration in the motor as described above, it is desired to reduce the thrust force. An object of the present invention is to provide a motor capable of reducing the thrust force.

  A motor for solving the above problems includes an A-phase stator portion in which coils are arranged between a first stator core and a second stator core having a plurality of claw-shaped magnetic poles, and a first stator core and a second stator core having a plurality of claw-shaped magnetic poles. A two-phase stator in which a B-phase stator portion in which a coil is arranged is arranged in parallel in the axial direction, and a rotor having a permanent magnet facing the claw-shaped magnetic poles of the A-phase and B-phase stator portions. The permanent magnet has an axially inner portion that is a boundary side between the A-phase and B-phase stator portions in the axial direction straddling the A-phase and B-phase stator portions. The magnetic force is set to be relatively weaker than the magnetic force of the axially outer portion that is opposite to the boundary portion between the A-phase and B-phase stator portions.

  In the axial direction straddling the A-phase and B-phase stator portions, the axially inner portion of the permanent magnet, which is the boundary portion between the A-phase and B-phase stator portions, is connected to the stator portions of different phases aligned in the axial direction. Magnetic influence is great. According to the above configuration in consideration thereof, since the magnetic force of the axially inner portion of the permanent magnet is set relatively weaker than the magnetic force of the axially outer portion, the oblique attractive force and repulsion to the stator portions of different phases are set. The force can be kept small, and the axial component of the force, that is, the thrust force can be reduced.

  In the motor, it is preferable that a magnetic force of the axially inner portion of the permanent magnet having a relatively weak magnetic force is set to 60% or more and less than 100% of a magnetic force of the axially outer portion.

  According to this configuration, since the magnetic force of the axially inner portion of the permanent magnet is set to 60% or more and less than 100% of the magnetic force of the axially outer portion, the thrust force can be reduced without significantly reducing the motor output. Can be reduced.

In the motor, it is preferable that the axially inner portion and the axially outer portion of the permanent magnet having relatively weak magnetic force are configured by separate magnets.
According to this configuration, since the axially inner portion and the axially outer portion that make the magnetic force different in the permanent magnet can be configured by separate magnets having different magnetic forces, the axially inner portion and the axially outer portion Embodiments with different magnetic forces can be easily realized.

  According to the motor of the present invention, the thrust force can be reduced.

The perspective sectional view of the motor of an embodiment. The exploded perspective view of the motor of the form. The disassembled perspective view of the stator of the same form. (A) (b) is explanatory drawing for demonstrating the positional relationship of the stator and rotor of the same form. (A) (b) is explanatory drawing for demonstrating the thrust force which generate | occur | produces in the motor of embodiment. The graph of the thrust force of embodiment and a 1st comparative example. The graph which shows the relationship between a magnetic pole characteristic ratio and thrust force in embodiment. The perspective sectional view of the motor of a reference embodiment. The exploded perspective view of the motor of the form. (A) is a disassembled perspective view of the stator of the same form, (b) is a partially enlarged view of (a). Explanatory drawing for demonstrating the thrust force which generate | occur | produces in the motor of reference embodiment. (A) (b) is explanatory drawing for demonstrating the positional relationship of the stator and rotor of the same form. The graph of the thrust force of reference embodiment and a 2nd comparative example. (A) (b) is an expansion perspective view of the stator core of another example. (A) (b) is a perspective view of the stator of another example.

Hereinafter, an embodiment of the motor will be described.
As shown in FIG. 1, the motor M1 of the present embodiment is a brushless motor, and includes a rotor 10 rotatably supported on a support shaft on a housing (not shown), and a stator 20 fixed to the housing. Yes.

  As shown in FIG. 1 and FIG. 2, the rotor 10 is composed of a two-phase rotor portion, that is, an A-phase rotor portion 11 and a B-phase rotor portion 12. The rotor core 13 made of a magnetic material and four magnets fixed to the rotor core 13 (A phase first magnet 14a, A phase second magnet 14b, B phase first magnet 15a, B phase second magnet 15b) ).

  The rotor core 13 has an inner peripheral cylindrical portion 13a having a cylindrical shape centered on the axis L of the rotor 10, and an outer peripheral side located on the outer peripheral side of the inner peripheral cylindrical portion 13a. It has a cylindrical portion 13b, and an upper bottom portion 13c that connects one axial end (upper end) of the inner peripheral cylindrical portion 13a and the outer peripheral cylindrical portion 13b. The upper bottom portion 13 c is formed in a flat plate ring shape orthogonal to the axis L. In the rotor core 13, the inner peripheral surface of the inner peripheral cylindrical portion 13 a is supported on a support shaft (not shown) via a bearing (also not shown).

  On the inner peripheral surface of the outer cylindrical portion 13b, the first A-phase magnet 14a, the second A-phase magnet 14b, and the first B-phase magnet are arranged in the axial direction from the open end side of the rotor core 13 toward the upper bottom portion 13c. 15a and B phase second magnet 15b are arranged in this order. The A-phase first and second magnets 14 a and 14 b have the same axial width and are provided at positions that face the A-phase stator portion 21, which will be described later, in the radial direction to constitute the A-phase rotor portion 11. Similarly, the B-phase first and second magnets 15a and 15b have the same axial width with respect to the A-phase first and second magnets 14a and 14b. The B-phase rotor portion 12 is provided at a position facing the radial direction of the rotor 22.

  The magnets 14a, 14b, 15a, 15b are magnetized in the radial direction, and the north and south poles are alternately arranged at equal intervals in the circumferential direction. Further, the number of poles is the same, and the rotor 10 of the present embodiment is configured with 12 poles (six pole pairs). Further, in the present embodiment, the A-phase first magnet 14a and the B-phase second magnet 15b respectively positioned on the axially outer side, and the A-phase second magnet 14b and the B-phase second magnet respectively positioned on the axially inner side. The magnetic characteristics are different from those of one magnet 15a. The axially outer A-phase first magnet 14a and the B-phase second magnet 15b are relatively stronger in magnetic force than the axially inner A-phase second magnet 14b and the B-phase first magnet 15a. In other words, the A-phase second magnet 14b and the B-phase first magnet 15a on the inner side in the axial direction are relatively more magnetic than the first A-phase magnet 14a and the B-phase second magnet 15b on the outer side in the axial direction. Those with weak magnetic properties are used. For example, when the magnetic characteristics (magnetic force) of the A-phase first magnet 14a and the B-phase second magnet 15b on the outer side in the axial direction are 100%, the second A-phase magnet 14b and the B-phase second magnet on the inner side in the axial direction. The magnetic characteristic (magnetic force) of one magnet 15a is set to 80%.

  The stator 20 includes stator portions 21 and 22 each having an annular shape. In the present embodiment, the stator portion 21 is used for the A phase and is supplied with an A phase drive current. The stator portion 22 is for the B phase and is supplied with a B phase drive current.

  The stator parts 21 and 22 have the same configuration and the same shape, and are arranged in parallel in the axial direction. The A-phase stator portion 21 is disposed on the axially open end side (lower side) of the rotor core 13, and the B-phase stator portion 22 is disposed on the upper bottom portion 13c side (upper side) in the axial direction. In addition, as a support structure of each stator part 21, 22, the A-phase stator part 21 is supported by the housing (not shown), and the B-phase stator part 22 is supported by the A-phase stator part 21. ing.

  In the motor M1 configured as described above, as shown in FIG. 1, the A-phase rotor including the A-phase stator portion 21 and the A-phase first and second magnets 14a and 14b disposed on the outer peripheral side thereof. The part 11 constitutes an A-phase motor part M1A. Similarly, the B-phase motor portion M1B is configured by the B-phase stator portion 22 and the B-phase rotor portion 12 including the B-phase first and second magnets 15a and 15b arranged on the outer peripheral side thereof. .

  As shown in FIG. 3, each of the A-phase and B-phase stator portions 21 and 22 has a pair of stator cores (first stator core 23 and second stator core 24) having the same shape, and the pair of stator cores 23 and 24. And a coil 25 disposed between the two.

  Each of the stator cores 23 and 24 includes a cylindrical portion 26 and a plurality of (12 in this embodiment) claw-shaped magnetic poles 27 and 28 extending from the cylindrical portion 26 to the outer peripheral side. The claw-shaped magnetic pole formed on the first stator core 23 is referred to as a first claw-shaped magnetic pole 27, and the claw-shaped magnetic pole formed on the second stator core 24 is referred to as a second claw-shaped magnetic pole 28. The claw-shaped magnetic poles 27 and 28 have the same shape. The first claw-shaped magnetic poles 27 are provided at regular intervals (30-degree intervals) in the circumferential direction, and the second claw-shaped magnetic poles 28 are similarly provided at regular intervals (30-degree intervals) in the circumferential direction.

  The claw-shaped magnetic poles 27 and 28 are bent at right angles so as to extend radially outward from the cylindrical portion 26 and to face the axial direction in the middle. Here, in each claw-shaped magnetic pole 27, 28, a portion extending radially outward from the cylindrical portion 26 is referred to as a radial extending portion 29a, and a tip portion bent in the axial direction is referred to as a magnetic pole portion 29b. The radially extending portion 29a is formed so that the circumferential width becomes narrower toward the outer peripheral side. The outer peripheral surface (radially outer surface) of the magnetic pole portion 29b is formed in an arc surface centered on the axis L.

  The stator cores 23 and 24 including the claw-shaped magnetic poles 27 and 28 having a right-angle shape may be manufactured by bending from a plate material, or may be manufactured by casting using a mold. Further, for example, the stator cores 23 and 24 may be made by mixing magnetic powder such as iron powder and an insulator such as resin and then heat-press molding with a mold. In this case, the degree of freedom in designing the stator cores 23 and 24 is increased, and the manufacturing process is greatly simplified. Moreover, the amount of suppression of eddy current can be easily adjusted by adjusting the distribution amount of magnetic powder and an insulator.

  The first and second stator cores 23 and 24 configured as described above are assembled such that the first and second claw-shaped magnetic poles 27 and 28 (magnetic pole portions 29b) face each other in the axial direction (see FIG. 3). In this assembled state, the magnetic pole portions 29b of the first claw-shaped magnetic poles 27 and the magnetic pole portions 29b of the second claw-shaped magnetic poles 28 are alternately arranged at equal intervals in the circumferential direction. That is, the stator 20 of the present embodiment is configured with 24 poles. The first and second stator cores 23 and 24 are fixed to each other with their cylindrical portions 26 in contact with each other in the axial direction.

  In this assembled state, a coil 25 is interposed between the axial directions of the first and second stator cores 23 and 24. The coil 25 is made of insulating resin interposed between a winding (not shown) wound in an annular shape along the circumferential direction of the stator 20 and the winding and the first and second stator cores 23 and 24. Bobbins (not shown). The coil 25 is disposed between the radial extension 29a of the first claw-shaped magnetic pole 27 and the radial extension 29a of the second claw-shaped magnetic pole 28 in the axial direction, and in the radial direction. It is disposed between the cylindrical portion 26 of each stator core 23, 24 and the magnetic pole portion 29 b of each claw-shaped magnetic pole 27, 28.

  The A-phase and B-phase stator portions 21 and 22 configured as described above have a so-called Landell type structure. That is, the A-phase and B-phase stator portions 21 and 22 cause the first and second claw-shaped magnetic poles 27 and 28 to be supplied by the current supplied to the coil 25 disposed between the first and second stator cores 23 and 24. From time to time, a 24-pole Randell structure that excites different magnetic poles is formed.

  As shown in FIGS. 1 and 2, the A-phase and B-phase stator portions 21 and 22 are arranged such that the second stator cores 24 face each other in the axial direction. Further, as described above, the A-phase stator portion 21 is disposed on the axially open end side (lower side) of the rotor core 13, and the B-phase stator portion 22 is disposed on the upper bottom portion 13c side (upper side) in the axial direction. Has been. Therefore, the first stator core 23 of the A-phase stator portion 21, the second stator core 24 of the A-phase stator portion 21, and the second phase of the B-phase stator portion 22 in the axial direction from the open end side of the rotor core 13 toward the upper bottom portion 13 c. The two stator cores 24 and the first stator core 23 of the B-phase stator portion 22 are arranged in this order.

  As for the positional relationship between the rotor 10 and the stator 20, the magnetic pole portion 29 b of the first claw-shaped magnetic pole 27 of the first stator core 23 in the A-phase stator portion 21 is the first A-phase magnet of the A-phase rotor portion 11. The whole axial direction of 14a and the 1/2 axial direction part of the 2nd A phase magnet 14b are opposed. The magnetic pole portion 29b of the second claw-shaped magnetic pole 28 of the second stator core 24 in the A-phase stator portion 21 includes the entire axial direction of the A-phase second magnet 14b of the A-phase rotor portion 11 and the A-phase first magnet 14a. It is opposed to a half part in the axial direction. In addition, the magnetic pole portion 29b of the second claw-shaped magnetic pole 28 of the second stator core 24 in the B-phase stator portion 22 includes the entire axial direction of the B-phase first magnet 15a of the B-phase rotor portion 12 and the B-phase second. It faces the ½ part in the axial direction of the magnet 15b. The magnetic pole portion 29b of the first claw-shaped magnetic pole 27 of the first stator core 23 in the B-phase stator portion 22 includes the entire axial direction of the B-phase second magnet 15b of the B-phase rotor portion 12 and the B-phase first magnet 15a. It is opposed to a half part in the axial direction.

Next, the positional relationship in the circumferential direction of the A-phase stator portion 21 and the B-phase stator portion 22 and the positional relationship in the circumferential direction of the A-phase rotor portion 11 and the B-phase rotor portion 12 will be described.
As shown in FIG. 4B, in the stator 20, the B-phase stator portion 22 is shifted from the A-phase stator portion 21 by an electrical angle θ <b> 1 (45 degrees in this embodiment) in the clockwise direction. ing. That is, the first and second claw-shaped magnetic poles 27 and 28 of the B-phase stator portion 22 are electrically angled in the clockwise direction with respect to the first and second claw-shaped magnetic poles 27 and 28 of the A-phase stator portion 21, respectively. The positions are shifted by (45 degrees in this embodiment).

  On the other hand, as shown in FIG. 4A, in the rotor 10, the first and second magnets 14 a and 14 b for the A phase and the first for the B phase in the A phase and B phase rotor portions 11 and 12, respectively. And magnets separated into two in the axial direction in each phase, such as second magnets 15a and 15b, are used. Here, in the A-phase and B-phase rotor sections 11 and 12, the B-phase rotor section 12 is counterclockwise to the A-phase rotor section 11 by an electrical angle θ2 (45 degrees in this embodiment). It is arranged just shifted. In other words, the reference positions La and Lb of the rotor portions 11 and 12 of the respective phases are shifted from each other by the electrical angle θ2.

  In the A-phase rotor unit 11, the A-phase second magnet is arranged such that the A-phase first magnet 14a is shifted from the reference position La in the clockwise direction by an electrical angle θ3 (22.5 degrees in this embodiment). 14b are respectively arranged so as to be shifted counterclockwise by the same electrical angle θ3. In the B-phase rotor section 12, the B-phase second magnet is arranged such that the B-phase first magnet 15a is shifted from the reference position Lb in the clockwise direction by an electrical angle θ4 (22.5 degrees in this embodiment). 15b are arranged so as to be shifted in the counterclockwise direction by the same electrical angle θ4. The adjacent second A-phase magnet 14b and the first B-phase magnet 15a have the same circumferential position depending on the shifting direction and the shifting angle.

  In the motor M1 of the present embodiment using the A-phase and B-phase rotor portions 11 and 12 having such a configuration and the above-described stator portions 21 and 22, the A-phase motor portion M1A and the B-phase motor portion M1B The phase difference is set to 90 degrees.

  The A-phase drive current is supplied to the coil 25 of the A-phase stator unit 21, and the B-phase drive current is supplied to the coil 25 of the B-phase stator unit 22. The A-phase drive current and the B-phase drive current are alternating currents, and the phase difference between them is set to 90 degrees in this embodiment. As a result, rotational torque is generated by the relationship between the stator portions 21 and 22 and the rotor portions 11 and 12, and the rotor 10 is driven to rotate.

  Incidentally, the claw-shaped magnetic poles 28 of the second stator core 24 of the respective stator portions 21 and 22 receive a thrust force when the rotor 10 is driven to rotate. Since the thrust force causes motor vibration and the like, reduction is desired.

  Specifically, as shown in FIG. 5A, the claw-shaped magnetic poles 28 of the stator core 24 of the A-phase stator portion 21 are not only the first and second A-phase magnets 14a and 14b opposed in the radial direction, Attraction force F1 is also received from the B-phase first and second magnets 15a and 15b adjacent to the magnets 14a and 14b. The suction force F1 is divided into a radial component F1x and an axial component F1y. The stator core 24 of the A-phase stator portion 21 receives this axial component F1y as an axial upward thrust force. In addition, when the claw-shaped magnetic poles 28 of the stator core 24 of the A-phase stator portion 21 receive the repulsive force F2 from the B-phase first and second magnets 15a and 15b, the radial component F2x and the axial component F2y are similarly generated. The stator core 24 of the A-phase stator portion 21 receives this axial component F2y as a downward thrust force in the axial direction.

  Similarly, as shown in FIG. 5B, the claw-shaped magnetic poles 28 of the stator core 24 of the B-phase stator portion 22 are not limited to the first and second B-phase magnets 15a and 15b opposed in the radial direction. Attraction force F3 is also received from the A-phase first and second magnets 14a and 14b. The suction force F3 is divided into a radial component F3x and an axial component F3y. The stator core 24 of the B-phase stator portion 22 receives this axial component F3y as axially downward thrust force. When the claw-shaped magnetic pole 28 of the stator core 24 of the B-phase stator portion 22 receives the repulsive force F4 from the A-phase first and second magnets 14a and 14b, the radial component F4x and the axial component F4y are similarly generated. The stator core 24 of the B-phase stator portion 22 receives this axial component F4y as an axially upward thrust force.

  Here, a motor (M10) as a first comparative example (not shown) for the motor M1 of the present embodiment will be described. The motor (M10) of the first comparative example has substantially the same configuration as the motor M1 of the present embodiment, but is a first magnet for A phase, a second magnet for A phase, a first magnet for B phase, and for B phase. The magnetic forces of the second magnets are all set to the same strength. Therefore, it is easy to be influenced by the magnetic force between different phases, and the thrust force S10 is relatively large as can be seen from the thrust force S10 of the motor (M10) of the first comparative example shown in FIG.

On the other hand, the thrust force S1 of the motor M1 of this embodiment shown in FIG. 6 is suppressed to be smaller than the thrust force S10 of the motor (M10) of the first comparative example.
Specifically, in the motor M1 of the present embodiment, the magnetic force of the B-phase first magnet 15a, which is disposed in proximity to the A-phase stator portion 21 and has a large influence, is relative to the magnetic force of the B-phase second magnet 15b. Therefore, the suction force F1 and the repulsive force F2 can be suppressed to be small. As a result, the thrust force that is the axial components F1y and F2y is reduced. Similarly, the magnetic force of the second A-phase magnet 14b, which is disposed close to the B-phase stator portion 22 and has a large influence, is set to be relatively weaker than the magnetic force of the first A-phase magnet 14a. In addition, the suction force F3 and the repulsive force F4 can be kept small. As a result, the thrust force that is the axial components F3y and F4y is reduced.

  FIG. 7 shows the thrust force when the magnetic characteristic ratio is changed. As is apparent from FIG. 7, when the magnetic characteristic ratio (ratio for weakening the magnetic force) is in the range of 100% to 60%, the thrust force decreases as the magnetic characteristic ratio decreases. When the magnetic characteristic ratio is in a range smaller than 60%, the change in the reduction amount of the thrust force is small even if the magnetic characteristic ratio is reduced. Further, considering that the output of the motor M1 becomes smaller as the magnetic characteristic ratio becomes smaller, in order to reduce the thrust force while maintaining the output of the motor M1, the magnetic characteristic ratio is set to 60% or more and less than 100%. It can be said that setting within the range is preferable.

Next, characteristic effects of the present embodiment will be described.
(1) An axially inner portion of the permanent magnet that is the boundary side between the A-phase and B-phase stator portions 21 and 22 in the axial direction across the A-phase and B-phase stator portions 21 and 22, that is, the A-phase The second magnet for b 14b and the first magnet for B phase 15a have a large magnetic influence on the stator portions 21 and 22 of different phases arranged in the axial direction. In the present embodiment, in consideration of this, the magnetic forces of the A-phase second magnet 14b and the B-phase first magnet 15a corresponding to the axially inner portion of the permanent magnet are the first A-phase corresponding to the axially outer portion. It is set relatively weaker than the magnetic force of the magnet 14a and the B-phase second magnet 15b. As a result, the oblique attractive forces F1, F3 and repulsive forces F2, F4 to the stator portions 21, 22 of different phases are suppressed to be small, and the axial components F1y, F2y, F3y, F4y, that is, the thrust force is reduced. Can do. As a result, it is possible to reduce the vibration of the motor M1.

  (2) The magnetic force of the A-phase second magnet 14b and the B-phase first magnet 15a on the relatively weak magnetic side is 60% of the magnetic force of the A-phase first magnet 14a and the B-phase second magnet 15b. Since it is set to 80% within the range of less than 100%, the thrust force can be reduced while maintaining the output of the motor M1.

  (3) Since the first A phase magnet 14a, the second A phase magnet 14b, the first B phase magnet 15a, and the second B phase magnet 15b are composed of separate magnets, By using magnets having different magnetic forces, it is possible to easily realize different modes of magnetic force between the axially inner portion and the axially outer portion.

In addition, you may change the said embodiment as follows.
In the above embodiment, the outer rotor type motor M1 is used. However, the present invention may be applied to an inner rotor type motor.

  In the above embodiment, the magnetic forces of the A-phase second magnet 14b and the B-phase first magnet 15a are set relatively weaker than the magnetic forces of the A-phase first magnet 14a and the B-phase second magnet 15b. However, only the A-phase second magnet 14b or only the B-phase first magnet 15a may be set relatively weak.

  In the above embodiment, the magnetic characteristic ratio of the A-phase second magnet 14b and the B-phase first magnet 15a is set to 80%, but may be set to other numerical values. In this case, it is preferable to set the balance with the output of the motor M1, for example, referring to FIG. 7, it is preferably 60% or more and less than 100%.

  In the above embodiment, the magnets 14a, 14b, 15a, 15b of the rotor 10 have 12 poles (six pole pairs) and the claw-shaped magnetic poles 27, 28 of the stator 20 have 24 poles, but the number of poles is limited to this. Not.

  In the A-phase and B-phase rotor portions 11 and 12 of the above embodiment, the magnets 14a and 14b and the magnets 15a and 15b divided in the axial direction are arranged for each phase. Three or more magnets may be arranged. Moreover, it is good also considering the magnet of each phase as a different number of division | segmentation numbers. Moreover, it is good also as a division | segmentation aspect of the magnet straddling both phases in the rotor parts 11 and 12 for A phases and B phases. Moreover, although the axial widths of the magnets 14a, 14b, 15a, and 15b are set to be equal, they may be different widths.

  The magnets 14a, 14b, 15a, 15b of the above embodiment are not particularly mentioned, but may be composed of a plurality of magnets divided for each magnetic pole or each magnetic pole pair, or formed as one cylindrical magnet. It may be what you did. Moreover, the aspect attached to the rotor core 13 may be sufficient, and it is good also as an aspect shape | molded integrally. Moreover, you may comprise by the integral magnet from the positional relationship of the 2nd magnet 14b for A phases, and the 1st magnet 15a for B phases.

<Reference embodiment>
The motor M2 of the reference embodiment is a brushless motor having substantially the same configuration as the motor M1 of the above embodiment. Therefore, for convenience of explanation, the same parts as those of the motor M1 of the above embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 8, the motor M <b> 2 of the reference embodiment includes a rotor 50 and a stator 60.
As shown in FIGS. 8 and 9, the rotor 50 is composed of a two-phase rotor portion of an A-phase rotor portion 51 and a B-phase rotor portion 52, and each of these rotor portions should be configured. The rotor core 13 made of a magnetic material and two magnets (A phase magnet 54 and B phase magnet 55) fixed to the rotor core 13 are provided.

  On the inner peripheral surface of the outer cylindrical portion 13b, an A-phase magnet 54 and a B-phase magnet 55 are arranged in this order in the axial direction from the open end side of the rotor core 13 toward the upper bottom portion 13c. The A-phase magnet 54 is provided at a position facing a later-described A-phase stator portion 61 in the radial direction, and constitutes an A-phase rotor portion 51. Similarly, the B-phase magnet 55 constitutes a B-phase rotor portion 52 provided at a position facing a B-phase stator portion 62 described later in the radial direction. The A-phase and B-phase magnets 54 and 55 are magnetized in the radial direction, and the N and S poles are alternately arranged at equal intervals in the circumferential direction. Further, the number of poles is the same, and the rotor 10 of the present embodiment is configured with 12 poles (six pole pairs). The magnetic properties (magnetic force) of the A-phase magnet 54 are the same as those of the B-phase magnet 55.

  The stator 60 includes stator portions 61 and 62 each having an annular shape. In the present embodiment, the stator portion 61 is for the A phase and is supplied with an A phase drive current. The stator portion 62 is for the B phase and is supplied with a B phase drive current.

  The stator portions 61 and 62 have the same configuration and the same shape, and are arranged in parallel in the axial direction. The A-phase stator portion 61 is disposed on the axially open end side (lower side) of the rotor core 13, and the B-phase stator portion 62 is disposed on the upper bottom portion 13c side (upper side) in the axial direction.

  In the motor M2 configured as described above, the A-phase motor unit M2A is configured by the A-phase stator unit 61 and the A-phase rotor unit 51 including the A-phase magnet 54 disposed on the outer peripheral side thereof. . Similarly, the B-phase motor unit M2B is configured by the B-phase stator unit 62 and the B-phase rotor unit 52 including the B-phase magnet 55 disposed on the outer peripheral side thereof.

  As shown in FIG. 10A, each of the A-phase and B-phase stator portions 61 and 62 has a pair of stator cores (first stator core 63 and second stator core 64) having the same shape, and the pair of stator cores. And a coil 25 disposed between 63 and 64.

  Each of the stator cores 63 and 64 is similar to the stator cores 23 and 24 of the above-described embodiment, and includes a cylindrical portion 26 and a plurality (12 in this embodiment) of first and second claws extending from the cylindrical portion 26 to the outer peripheral side. Shaped magnetic poles 27 and 28. Each of the claw-shaped magnetic poles 27 and 28 includes a radially extending portion 29a that extends radially outward from the cylindrical portion 26 and a magnetic pole portion 29b that is bent in the axial direction.

  In the present embodiment, as shown in FIGS. 10B and 11, an inclined portion 29d is formed at a boundary portion 29c between the radially extending portion 29a and the magnetic pole portion 29b. The inclined portion 29d of the present embodiment is formed by chamfering the boundary portion 29c that becomes a corner portion by bending.

  Here, as shown in FIG. 11, the dimension in the axial direction of the inclined portion 29d of the A-phase stator portion 61 (B-phase stator portion 62) is L1, and the root of the magnetic pole portion 29b (of the radially extending portion 29a). The dimension from the outer surface) to the tip surface is L2. The axial dimension of the A-phase magnet 54 facing the A-phase stator portion 61 (B-phase magnet 55 facing the B-phase stator portion 62) is L3. The dimension L1 of the inclined portion 29d is set so as to satisfy L1 = L3-L2.

Next, the positional relationship between the rotor 50 and the stator 60 will be described.
As shown in FIG. 12A, in the rotor 50, the B-phase magnet 55 of the B-phase rotor portion 52 is counterclockwise with respect to the A-phase magnet 54 of the A-phase rotor portion 51. In this embodiment, they are shifted by 45 degrees. On the other hand, in the stator 60, as shown in FIG. 12B, the first and second claws of the B-phase stator portion 62 with respect to the first and second claw-shaped magnetic poles 27 and 28 of the A-phase stator portion 61. The magnetic poles 27 and 28 are arranged so as to be shifted clockwise by an electrical angle θ1 (45 degrees in this embodiment). That is, in the motor M1 of this embodiment, the phase difference between the A-phase motor unit M2A and the B-phase motor unit M2B is set to 90 degrees.

  FIG. 13 shows the thrust force S2 of the motor M2 provided with the inclined portion 29d of the present embodiment, and the motor (M20) as a second comparative example (not shown), that is, the radial extension portion without the inclined portion 29d. 29a and the thrust force S20 of the motor (M20) in which the boundary part 29c of the magnetic pole part 29b is angular. The motor (M20) of the second comparative example is easily affected by magnetic force between different phases, and is relatively large like a thrust force S20 shown in FIG.

  On the other hand, the thrust force S2 of the motor M2 of this embodiment shown in FIG. 13 is suppressed to be smaller than the thrust force S20 of the motor (M20) of the second comparative example. This is considered that the balance of the axial component of the attractive force and the repulsive force received by the claw-shaped magnetic poles 27 and 28 of the stator cores 63 and 64 of this embodiment is better than that of the second comparative example.

  Specifically, as shown in FIG. 11, in the A-phase stator portion 61, the magnetic pole portion 29 b of the first claw-shaped magnetic pole 27 of the stator core 63 is attracted in three directions from the A-phase magnet 54 (radially outward). A suction force F11, a diagonally upward suction force F12, and a diagonally downward suction force F13). The diagonally downward attractive force F <b> 13 is a force generated by forming the inclined portion 29 d on the first claw-shaped magnetic pole 27. The axial component F12y of the suction force F12 obliquely upward is upward in the axial direction, and the axial component F13y of the suction force F13 obliquely downward is downward in the axial direction. As a result, the axial component F12y and the axial component F13y cancel each other, and the thrust force received by the entire first claw-shaped magnetic pole 27 is reduced. The claw-shaped magnetic poles 28 of the stator core 64 of the A-phase stator section 61 and the claw-shaped magnetic poles 27 and 28 of the stator cores 63 and 64 of the B-phase stator section 62 are not shown, but are illustrated. As with the claw-shaped magnetic pole 27 of the stator core 63, the thrust force is reduced. The same applies to the repulsive force.

  The dimension L1 of the inclined portion 29d is set so as to satisfy L1 = L3-L2. For this reason, the center position P in the axial direction of the magnetic pole part 29b excluding the inclined part 29d and the center position Q in the axial direction of the A-phase magnet 54 substantially coincide with each other, and the axial component F12y of the attractive force F12 obliquely upward. And the magnitude of the axial component F13y of the suction force F13 obliquely downward are substantially the same. As a result, the axial component remaining due to cancellation of the axial component F12y and the axial component F13y becomes substantially zero, and the thrust force is more effectively reduced.

In addition, you may change the said embodiment as follows.
In the above embodiment, the outer rotor type motor M2 is used. However, the present invention may be applied to an inner rotor type motor.

In the above embodiment, the magnets 54 and 55 of the rotor 50 are 12 poles (six pole pairs) and the claw-shaped magnetic poles 27 and 28 of the stator 60 are 24 poles, but the number of poles is not limited to this.
In the above embodiment, the stator 60 is a two-phase stator including the A-phase stator portion 61 and the B-phase stator portion 62, but may be a single-phase stator.

  In the above embodiment, the inclined portion 29d is formed in the stator cores 63 and 64 of the stator portions 61 and 62, but is formed only in the A-phase stator portion 61 or only in the B-phase stator portion 62. May be.

  In the above embodiment, the inclined portion 29d is provided at the boundary portion 29c of the claw-shaped magnetic poles 27 and 28. However, as shown in FIG. 14A, the inclined portion 29d is replaced by the outer peripheral surface of the magnetic pole portion 29b. You may form the recessed part 29e which makes a concave shape inside radial direction. Also in this case, the thrust force can be reduced by functioning similarly to the inclined portion 29d.

  Further, the size and position of the recess 29e and the length of the recess 29e may be changed as appropriate. For example, as shown in FIG. 14B, the thrust force may be adjusted by forming a convex portion 29f in the concave portion 29e (providing a portion to be left without being formed as a concave portion). Further, the size and position of the convex portion 29f may be changed as appropriate.

  The position restriction members 65 and 66 made of an insulating material for restricting the displacement of the first and second stator cores 63 and 64 may be provided in the stator portions 61 and 62 of the above embodiment.

  For example, an annular position restricting member 65 is provided in the stator portions 61 and 62 shown in FIG. The position restricting member 65 includes a circumferential restricting portion 65 a disposed between the claw-shaped magnetic pole 27 and the claw-shaped magnetic pole 28 in the circumferential direction, a tip side of the magnetic pole portion 29 b of the claw-shaped magnetic pole 27, and a magnetic pole portion 29 b of the claw-shaped magnetic pole 28. And axial direction restricting portions 65b arranged alternately on the front end side.

  The circumferential direction restricting portion 65a restricts the claw-shaped magnetic poles 27 and 28 of the stator cores 63 and 64 from being displaced in the circumferential direction. On the other hand, the axial direction restricting portion 65b restricts the stator cores 63 and 64 from coming outside in the axial direction. As a result, the assembled state of the first and second stator cores 63, 64 of the stator portions 61, 62 is strengthened.

  As another example, a plurality of position restricting members 66 are provided in the stator portions 61 and 62 shown in FIG. Each position restricting member 66 includes a circumferential direction restricting portion 66 a disposed between the claw-shaped magnetic pole 27 and the claw-shaped magnetic pole 28 in the circumferential direction. One end in the axial direction of the circumferential restricting portion 66a is provided with a first axial restricting portion 66b extending to one circumferential side, and the other axial end of the circumferential restricting portion 66a extends to the other circumferential side. The 2nd axial direction control part 66c to come out is provided. The dimensions of the first and second axial direction restricting portions 66b and 66c are set to be about half the circumferential width of the claw-shaped magnetic poles 27 and 28.

  The circumferential direction restricting portion 66a restricts the claw-shaped magnetic poles 27 and 28 of the stator cores 63 and 64 so as not to be displaced in the circumferential direction. On the other hand, the first axial direction restricting portion 66b and the second axial direction restricting portion 66c cooperate to restrict the stator cores 63 and 64 from coming outside in the axial direction. As a result, the assembled state of the first and second stator cores 63, 64 of the stator portions 61, 62 is strengthened.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) A claw-shaped magnetic pole comprising a first stator core having a plurality of claw-shaped magnetic poles, a second stator core having a plurality of claw-shaped magnetic poles, and a coil disposed between the first stator core and the second stator core. Is a stator having a radially extending portion that extends radially outward, and a magnetic pole portion having a distal end of the radially extending portion bent in the axial direction, wherein the radially extending portion and the magnetic pole portion The stator is characterized in that an inclined surface or a recess is provided at a boundary portion between the stator and the stator.

  According to this configuration, since the inclined surface or the concave portion is provided at the boundary portion between the radial extension portion and the magnetic pole portion of the claw-shaped magnetic pole, the motor is combined with the rotor having the permanent magnet facing the magnetic pole portion in the radial direction. In this case, the balance between the axial components of the attractive force and the repulsive force that the claw-shaped magnetic poles (magnetic pole portions) of the first and second stator cores receive from the permanent magnet of the rotor is improved. As a result, the axial components of the suction force (and the repulsive force) cancel each other, and the thrust force is reduced.

(B) A motor comprising the stator according to appendix (a), and a rotor having a permanent magnet radially opposed to a magnetic pole portion of the claw-shaped magnetic pole of the stator.
(C) In the motor according to appendix (b), the axial dimension of the inclined surface or the recess is L1, the dimension from the root of the magnetic pole part to the tip surface is L2, and the axial dimension of the permanent magnet is A motor that satisfies L1 = L3-L2 when L3 is satisfied.

  According to this configuration, the central position in the axial direction of the magnetic pole part excluding the inclined surface or the concave portion substantially coincides with the central position in the axial direction of the permanent magnet. For this reason, the balance of the axial component of the attractive force received by the claw-shaped magnetic poles of the first and second stator cores from the permanent magnet of the rotor is improved (the repulsive force is the same). As a result, the axial component remaining due to cancellation of the axial components of the suction force becomes substantially zero (the same applies to the repulsive force), and the thrust force can be reduced more effectively.

  M1 ... Motor, 10 ... Rotor, 14a ... A phase first magnet (axially outer portion), 14b ... A phase second magnet (axially inner portion), 15a ... B phase first magnet (axially inner) Part), 15b ... B-phase second magnet (axially outer part), 20 ... stator, 21 ... A-phase stator part, 22 ... B-phase stator part, 23 ... first stator core, 24 ... second stator core, 25 ... Coil, 27 ... First claw-shaped magnetic pole (claw-shaped magnetic pole), 28 ... Second claw-shaped magnetic pole (claw-shaped magnetic pole).

Claims (3)

A phase stator having a coil disposed between a first stator core and a second stator core having a plurality of claw-shaped magnetic poles, and B having a coil disposed between a first stator core and a second stator core having a plurality of claw-shaped magnetic poles A two-phase stator in which a phase stator portion is arranged in parallel in the axial direction;
A motor comprising a rotor having a permanent magnet facing the claw-shaped magnetic poles of the A-phase and B-phase stator parts,
In the axial direction straddling the A-phase and B-phase stator portions, the permanent magnet has a magnetic force in an axially inner portion that is a boundary side between the A-phase and B-phase stator portions. A motor characterized in that it is set to be relatively weaker than the magnetic force of an axially outer portion that is opposite to the boundary portion of the B-phase stator portion. The motor according to claim 1,
The motor according to claim 1, wherein the permanent magnet has a relatively weak magnetic force in the axially inner portion set to 60% or more and less than 100% of the magnetic force in the axially outer portion. The motor according to claim 1 or 2,
The motor characterized in that the axially inner portion and the axially outer portion of the permanent magnet having relatively weak magnetic force are constituted by separate magnets.

Images