JP2015149879A - Rotor and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor that can easily perform magnetization for suppressing flux leakage while reducing the number of parts.SOLUTION: A rotor 4 has a first rotor core 20 having a first pawl-shaped magnetic pole 22 formed at the outer peripheral portion of a first core base 21, a second rotor core 30 having a second pawl-shaped magnetic pole 32 formed at the outer peripheral portion of a second core base 31, a field magnet 40 which is disposed between the first and second core bases 21, 31 and magnetized in an axial direction to make the first pawl-shaped magnetic pole 22 function as a first magnetic pole and make the second pawl-shaped magnetic pole 32 as a second magnetic pole, a back surface magnet 50 which is disposed between the first and second pawl-shaped magnetic poles 22, 32 and the field magnetic 40 and suppresses flux leakage therebetween, and an inter-pole magnet 51 which is disposed between the first and second pawl-shaped magnetic poles 22, 32 adjacent in the peripheral direction and suppresses flux leakage therebetween. The back surface magnet 50 and the inter-pole magnet 51 is annularly and integrally formed and forms an auxiliary magnet G so that the end faces thereof in the axial direction form one flat plane H.

Description

  The present invention relates to a rotor and a motor.

  The rotor of the motor includes two rotor cores that are combined with a plurality of claw-shaped magnetic poles on the outer periphery of the core base, and a field magnet that is arranged between the axial directions and magnetized in the axial direction. There is a so-called permanent magnet field Landel-type rotor in which each claw-shaped magnetic pole functions alternately as a different magnetic pole. Such a rotor is arranged between the claw-shaped magnetic poles arranged between the claw-shaped magnetic poles and the field magnet and magnetized in the radial direction to suppress leakage magnetic flux therebetween, and the claw-shaped magnetic poles adjacent in the circumferential direction. And an inter-pole magnet that is magnetized in the circumferential direction and suppresses leakage magnetic flux therebetween (see, for example, Patent Document 1).

  Patent Document 2 discloses a technique for reducing the number of parts by integrally forming the back magnet and the interpole magnet in the rotor as described above.

JP 2012-115085 A JP 2013-118801 A

However, in the rotor as described above, since the back magnet and the interpole magnet have a shape in which the projections and depressions are repeated in the axial direction, it is difficult to effectively magnetize the rotor.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a rotor and a motor capable of easily performing magnetization for suppressing leakage magnetic flux while reducing the number of components. It is to provide.

  In the rotor that solves the above-described problems, a plurality of claw-shaped magnetic poles are projected radially outward at equal intervals on the outer periphery of the core base, and are extended in the axial direction. The claw-shaped magnetic poles of the first rotor core are arranged between the first and second rotor cores in which the magnetic poles are alternately arranged in the circumferential direction, and are magnetized in the axial direction between the core bases. Is disposed between the claw-shaped magnetic pole and the field magnet, and the leakage between the field magnet and the field magnet that functions as the first magnetic pole and the claw-shaped magnetic pole of the second rotor core as the second magnetic pole. A rotor including a back magnet for suppressing magnetic flux and an interpole magnet disposed between the claw-shaped magnetic poles adjacent to each other in the circumferential direction for suppressing leakage magnetic flux therebetween, wherein the back magnet and the pole The axial end surface of the magnet It is integrally formed auxiliary magnets annularly so that One of the flat surfaces.

  According to this configuration, the back magnet and the interpole magnet are formed as auxiliary magnets that are integrally formed in an annular shape so that the end surface in the axial direction is a flat surface. Can be easily magnetized.

A motor that solves the above problem includes the rotor and a stator that generates a rotating magnetic field.
According to this configuration, the above-described effect can be obtained in the motor.

  In the rotor and motor of the present invention, magnetization for suppressing leakage flux can be easily performed while reducing the number of parts.

The partial sectional view of the brushless motor in one embodiment. The partial sectional view of the rotor in one embodiment. The perspective view of the rotor in one Embodiment. The disassembled perspective view of the rotor in one Embodiment. The perspective view of the magnetizing apparatus for manufacturing the auxiliary magnet in one Embodiment.

Hereinafter, an embodiment of a brushless motor will be described with reference to FIGS.
As shown in FIG. 1, a brushless motor M as a motor has a stator 2 fixed to an inner peripheral surface of a motor housing 1, and is fixed to a rotating shaft 3 on the inner side of the stator 2 and rotates together with the rotating shaft 3. A so-called Landel-type rotor 4 is disposed. The rotating shaft 3 is a stainless steel shaft made of a magnetic material, and is supported by a bearing (not shown) provided on the motor housing 1 so as to be rotatable with respect to the motor housing 1.

  The stator 2 has a cylindrical stator core 10, and the outer peripheral surface of the stator core 10 is fixed to the inner surface of the motor housing 1. Inside the stator core 10, a plurality of teeth 11 formed along the axial direction and arranged at equal pitches in the circumferential direction are formed extending inward in the radial direction. Each tooth 11 is a T-shaped tooth, and an inner circumferential surface 11a on the radially inner side is an arc surface obtained by extending a concentric circular arc centering on the central axis O of the rotating shaft 3 in the axial direction. .

  Slots 12 are formed between the teeth 11 in the circumferential direction. In the present embodiment, the number of teeth 11 is twelve, and the number of slots 12 is twelve, which is the same as the number of teeth 11. Around the 12 teeth 11, three-phase windings in the circumferential direction, that is, a U-phase winding 13 u, a V-phase winding 13 v, and a W-phase winding 13 w are sequentially wound by concentrated winding. Is placed inside.

  Then, a three-phase power supply voltage is applied to each of the phase windings 13u, 13v, 13w to generate a rotating magnetic field in the stator 2, and the rotor 4 fixed to the rotating shaft 3 disposed inside the stator 2 is rotated. It is like that.

As shown in FIGS. 2 to 4, the rotor 4 includes first and second rotor cores 20 and 30, a field magnet 40, and an auxiliary magnet G.
The first rotor core 20 is made of a soft magnetic material and is formed of an electromagnetic steel plate in the present embodiment, and has a substantially disk-shaped first core base 21 in which a central hole 21a into which the rotary shaft 3 is press-fitted is formed. Yes. A plurality of (four in the present embodiment) first claw-shaped magnetic poles 22 project outward in the radial direction and extend in the axial direction on the outer peripheral portion of the first core base 21 at equal intervals.

  The second rotor core 30 has the same material and the same shape as the first rotor core 20 and has a substantially disc-shaped second core base 31 in which a central hole 31a into which the rotary shaft 3 is press-fitted is formed. A plurality of (four in the present embodiment) second claw-shaped magnetic poles 32 project outward in the radial direction and extend in the axial direction on the outer peripheral portion of the second core base 31 at equal intervals.

  And the 1st and 2nd rotor cores 20 and 30 are fixed with respect to the rotating shaft 3 by press-fitting the rotating shaft 3 in the center holes 21a and 31a. At this time, the second rotor core 30 is arranged such that each second claw-shaped magnetic pole 32 is disposed between the first claw-shaped magnetic poles 22 adjacent in the circumferential direction, and the first core base 21 and the second core base 31 The field magnet 40 is assembled (attached) to the first rotor core 20 in such a manner that the field magnet 40 is disposed (sandwiched) between the first rotor core 20 and the second magnet 20.

  As shown in FIG. 2, the field magnet 40 is a substantially disk-shaped permanent magnet having a central hole, and the first claw-shaped magnetic pole 22 is replaced with a first magnetic pole (N pole in this embodiment). And the second claw-shaped magnetic pole 32 is magnetized in the axial direction so as to function as a second magnetic pole (S pole in this embodiment). That is, the rotor 4 of the present embodiment is a so-called Landel type rotor. In the rotor 4, four first claw-shaped magnetic poles 22 that are N poles and four second claw-shaped magnetic poles 32 that are S poles are alternately arranged in the circumferential direction, and the number of poles is eight (the number of pole pairs). Is 4). That is, in this embodiment, the number of magnetic poles (number of poles) of the rotor 4 is set to “8”, and the number of teeth 11 (slots 12) of the stator 2 is set to “12”. Yes.

  The auxiliary magnet G is formed by integrally forming a back magnet 50 and an interpole magnet 51. Specifically, the back magnet 50 is provided between the first and second claw-shaped magnetic poles 22 and 32 in the radial direction (back surface) and the field magnet 40 when viewed from the axial direction, and leakage of the portion ( Shorted) Magnetized to reduce magnetic flux. The interpole magnet 51 is provided between the first and second claw-shaped magnetic poles 22 and 32 in the circumferential direction when viewed from the axial direction, and is magnetized so as to suppress the leakage magnetic flux at that portion. In other words, the interpole magnet 51 is formed so as to connect the back magnets 50 adjacent to each other in the circumferential direction when viewed from the axial direction, and the auxiliary magnet G has an annular shape, and the first and second claw-shaped magnetic poles 22, It is set as the shape which protruded in the radial direction outer side from the back magnet 50 so that it may also arrange | position between 32 axially extending (tip) parts.

  The auxiliary magnet G of the present embodiment is formed by integrally forming the back magnet 50 and the interpole magnet 51 in an annular shape so that the end surface in the axial direction becomes one flat surface H. That is, when the back magnet 50 and the interpole magnet 51 are arranged so that the rotor 4 has a substantially cylindrical shape with no gap, the auxiliary magnet G has a shape having irregularities in the axial direction, but the convex portion is not formed. Thus, the end surface in the axial direction is a single flat surface H. In other words, the auxiliary magnet G (the back magnet 50 and the interpole magnet 51) is formed with a uniform thickness except for the axial range in which the first core base 21 and the second core base 31 are arranged.

  The auxiliary magnet G is a polar anisotropic magnet, and is oriented as schematically shown by the arrows in FIGS. 4 and 5 so as to suppress the leakage flux by the back magnet 50 and the interpole magnet 51, respectively. Is magnetized.

  For example, as shown in FIG. 5, the magnetizing device 60 for manufacturing the auxiliary magnet G has a plurality of magnetized core portions 61 extending radially inward so as to be close to the outer peripheral surface of the portion to be the back magnet 50. And a coil 62 wound around each magnetized core portion 61. The auxiliary magnet G is manufactured by flowing a large current in the reverse direction to the coils 62 adjacent in the circumferential direction.

Next, the operation of the brushless motor M configured as described above will be described.
When a three-phase power supply voltage is applied to each phase winding 13u, 13v, 13w of the stator core 10 and a rotating magnetic field is generated in the stator 2, the rotor 4 fixed to the rotating shaft 3 disposed inside the stator 2 is provided. Is driven to rotate based on the rotating magnetic field.

  At this time, in the rotor 4, leakage magnetic flux in the portion (radial direction) is suppressed by the back magnet 50 in the auxiliary magnet G, and leakage magnetic flux in the portion (circumferential direction) is caused by the interpolar magnet 51 in the auxiliary magnet G. Therefore, it is rotationally driven by acting with the rotating magnetic field of the stator 2 with high efficiency.

Next, the characteristic effects of the above embodiment will be described below.
(1) Since the back magnet 50 and the interpole magnet 51 are the auxiliary magnets G that are integrally formed in an annular shape so that the end surfaces in the axial direction become one flat surface H (that is, there is no unevenness). Magnetization for suppressing leakage magnetic flux can be easily performed while reducing the number of parts. In other words, since the three-dimensional magnetization including the axial direction is unnecessary at the time of magnetization, for example, as shown in FIG. It is only necessary to make them close to each other, and magnetization becomes easy. Moreover, since there is no unevenness in the axial direction, the molding becomes easy. Further, when the back magnet 50 and the interpole magnet 51 are provided separately, they may be lost during assembly or the like, but this can be avoided. Further, in the case where the back magnet 50 and the interpole magnet 51 are provided separately, if the fixing force is weak, they may be scattered (dropped off) by centrifugal force during rotation, but this can be suppressed.

The above embodiment may be modified as follows.
-Although it does not mention in particular in the said embodiment, the kind by the material and manufacturing method of the field magnet 40 and the auxiliary magnet G is not specifically limited, You may use various magnets. For example, a ferrite magnet, a samarium iron nitrogen-based magnet, a samarium cobalt-based magnet, a neodymium magnet, or an alnico magnet may be used. Further, for example, a sintered magnet or a bonded magnet may be used. Moreover, when it is set as a bonded magnet, it is good also as compression molding and good also as injection molding.

  In the above embodiment, the brushless motor M is embodied in which the number of poles of the rotor 4 is set to “8” and the number of teeth 11 of the stator 2 is set to “12”, but the number of poles of the rotor 4 and the stator The number of the two teeth 11 may be changed. For example, the present invention may be embodied in a brushless motor in which the number of poles of the rotor 4 is set to “10” and the number of teeth 11 of the stator 2 is set to “12”.

  DESCRIPTION OF SYMBOLS 2 ... Stator, 4 ... Rotor, 20 ... 1st rotor core, 21 ... 1st core base (core base), 22 ... 1st claw-shaped magnetic pole (claw-shaped magnetic pole), 30 ... 2nd rotor core, 31 ... 2nd core base (Core base), 32 ... second claw-shaped magnetic pole (claw-shaped magnetic pole), 40 ... field magnet, 50 ... back magnet, 51 ... interpole magnet, G ... auxiliary magnet, H ... flat surface.

Claims (2)

A plurality of claw-shaped magnetic poles projecting radially outward and extending in the axial direction at equal intervals on the outer periphery of the core base, and the claw-shaped magnetic poles alternately in the circumferential direction while facing each other's core base Disposed first and second rotor cores;
The claw-shaped magnetic poles of the first rotor core function as the first magnetic poles by being arranged between the axial directions of the core bases and magnetized in the axial direction, and the claw-shaped magnetic poles of the second rotor core are made to function as the first magnetic poles. A field magnet that functions as a second magnetic pole;
A back magnet disposed between the claw-shaped magnetic pole and the field magnet, for suppressing leakage magnetic flux therebetween,
A rotor provided between the claw-shaped magnetic poles adjacent to each other in the circumferential direction, and an interpole magnet for suppressing leakage magnetic flux between them,
The rotor, wherein the back magnet and the interpole magnet are auxiliary magnets that are integrally formed in an annular shape so that an end face in the axial direction is a flat surface. A rotor according to claim 1;
A motor comprising a stator that generates a rotating magnetic field.