JP5587683B2 - motor - Google Patents

Description

  The present invention relates to a motor having a rotor adopting a continuous pole type structure.

  Conventionally, in a motor, for example, as shown in Patent Document 1, a plurality of magnets of one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the core are arranged between the magnets, One having a so-called consequent pole type rotor in which the salient pole functions as the other magnetic pole is known. Such a motor is advantageous in terms of resource saving, low cost, and the like because it is possible to reduce the number of magnets of the rotor to half while suppressing a decrease in performance.

JP 9-327139 A

  By the way, a rotor having a consequent pole type structure as in Patent Document 1 is composed of a magnetic pole in which a magnet having a magnetic flux forcing force (induction) and a salient pole without a magnetic flux forcing force are mixed. Magnetic imbalance is likely to occur, which leads to deterioration in rotational performance such as increased vibration due to the generation of cogging torque.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor capable of reducing vibration and improving rotational performance.

In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a plurality of magnets of one magnetic pole are arranged at equal intervals in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are provided between the magnets. And a core configured to function as the other magnetic pole, and a core that is disposed on the outer peripheral side of the rotor and has teeth that extend radially and are equally spaced in the circumferential direction. A motor having a stator having a multi-phase winding mounted on the teeth, and the plurality of salient poles are arranged at equal intervals in the circumferential direction, a first salient pole portion is the opening angle of the outer side surface different second salient pole around the axis of the rotor is configured Nde including, the magnet, the first salient pole portion and the second collision From the extreme Characterized in that a large circumferential length.

  In this invention, since the open angles of the outer surface of the first salient pole part and the second salient pole part of the rotor are different from each other, the timing at which the cogging torque is generated at the first salient pole part and the second salient pole part is shifted. . For this reason, it is possible to reduce the cogging torque generated in the entire motor as compared with a configuration in which the salient poles have a uniform opening angle, and the rotational performance of the rotor can be improved.

  According to a second aspect of the present invention, in the motor of the first aspect, when the open angle of the outer surface of the salient pole is changed, the cogging torque generated at the salient pole is shifted from the positive phase to the opposite phase. The boundary angle at which the cogging torque is inverted is “α”, and the boundary angle at which the cogging torque is phase-inverted from the opposite phase to the positive phase is “β” (where α <β). The opening angle of any one of the outer surfaces is set to be less than the boundary angle α or larger than the boundary angle β, and the opening angle of the other outer surface is not less than the boundary angle α and the boundary angle It is characterized by being set to β or less.

  In the present invention, the open angle of the outer surface of the first and second salient pole portions is set so that the cogging torques generated at the first and second salient pole portions are mutually phase-inverted. For this reason, since the cogging torque generated at the first salient pole portion is suppressed by the cogging torque generated at the second salient pole portion, the cogging torque can be more reliably reduced.

  According to a third aspect of the present invention, in the motor according to the second aspect, an open angle of either one of the first salient pole portion and the second salient pole portion is set to be less than the boundary angle α. The opening angle of the other outer surface is set to be not less than the boundary angle α and not more than {(α + β) / 2}.

  In this invention, the open angle of the outer surface of one of the first and second salient pole portions is set to be less than the boundary angle α, and the other open angle is within the range of the boundary angle α and the boundary angle β. It is set to an angle from the boundary angle α rather than the middle angle of the boundary angles α and β. Accordingly, it is possible to increase the circumferential interval between the first and second salient pole portions and the magnet while reversing the phases of the cogging torque generated at the first and second salient pole portions. Thus, it is possible to reduce the leakage magnetic flux caused by the narrow circumferential interval between the first and second salient pole portions and the magnet.

  According to a fourth aspect of the present invention, in the motor according to the second aspect, an open angle of one of the first and second salient pole portions is set to a value larger than the boundary angle β. In addition, the opening angle of the other outer surface is set to be not less than {(α + β) / 2} and not more than the boundary angle β.

  In this invention, the open angle of the outer surface of one of the first and second salient pole portions is set to a value larger than the boundary angle β, and the other open angle is in the range of the boundary angle α and the boundary angle β. Among these, the angle is set to be an angle from the boundary angle β rather than the middle angle between the boundary angles α and β. As a result, it is possible to reduce the circumferential interval between the first and second salient pole portions and the magnet while reversing the phases of the cogging torque generated at the first and second salient pole portions. Further, it is possible to suppress a reduction in torque due to the wide circumferential interval between the first and second salient pole portions and the magnet.

According to a fifth aspect of the present invention, in the motor according to the first aspect, the stator winding is constituted by distributed winding.
According to the present invention, it is possible to reduce cogging torque in a motor having a stator in which a coil is composed of distributed windings, and it is possible to improve the rotational performance of the rotor.

  Therefore, according to the above described invention, it is possible to reduce the vibration and improve the rotation performance.

(A) The schematic block diagram of the motor of this embodiment, (b) The elements on larger scale of the rotor in the same figure (a). The graph which shows the relationship between the opening angle of a salient pole and the amplitude of cogging torque. The characteristic view which shows the relationship between the rotation angle of a rotor, and cogging torque. The schematic diagram which shows the relationship between the salient pole and teeth in this embodiment. (A) The perspective view which shows the rotor of another example, (b) The top view which shows a 1st rotor core, (c) The top view which shows a 2nd rotor core. The perspective view which shows the rotor of another example. (A) The perspective view of the rotor of another example, (b) The side view of the figure (a), (c) The top view which looked at the rotor of the figure (a) from the axial direction other end side, (d) The figure The top view which looked at the rotor of (a) from the axial direction one end side. (A) (b) The perspective view of the rotor of another example. The perspective view of the rotor of another example. The schematic block diagram of the motor of another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1A, the inner rotor type motor 1 of the present embodiment is configured by a rotor 3 being arranged inside a substantially annular stator 2.

  As shown in FIGS. 1A and 1B, the stator 2 includes a cylindrical portion 11 and teeth 12 that extend radially inward from the cylindrical portion 11 and are provided in the circumferential direction (60 in the present embodiment). A stator core 4 is provided. Between each tooth 12 of the stator core 4, a slot S into which a segment winding 13 for generating a magnetic field for rotating the rotor 3 is inserted is formed. That is, the number of slots S is the same as the number of teeth 12 (60 in this embodiment). Note that an insulator (not shown) is interposed between the teeth 12 and the segment windings 13.

  The segment winding 13 of the stator 2 is a multi-phase (three-phase in this embodiment) distributed winding. The segment winding 13 includes a slot insertion portion 14a disposed in the slot S so as to penetrate the slot S between the teeth 12 in the axial direction (perpendicular to the plane of the drawing), and a slot protruding portion ( And a plurality of segment conductors 14 for each phase. The segment conductors 14 for each phase are configured to be electrically connected in the circumferential direction at the slot protrusions. Each segment conductor 14 is formed in a substantially U shape by bending a conductor plate, and a pair of slot insertion portions 14a corresponding to U-shaped parallel straight portions includes six pieces in the circumferential direction. They are arranged in two slots S that are separated from each other across the teeth 12.

  In the rotor 3, a substantially annular rotor core 22 made of a magnetic metal material is fixed to the outer peripheral surface of the rotating shaft 21, and four N-pole magnets 23 are arranged at equal circumferential intervals on the outer peripheral portion of the rotor core 22. ing. Further, between the magnets 23, the first salient poles 31 and the second salient poles 32 that are integrally formed on the outer peripheral portion of the rotor core 22 are alternately arranged in the circumferential direction one by one. That is, the magnets 23 and the salient poles 31 and 32 are alternately arranged at equiangular intervals (in this case, arranged at 45 ° intervals), and the rotor 3 is first and second with respect to the N-pole magnet 23. The salient poles 31 and 32 are configured as a so-called continuous pole type having eight magnetic poles that function as S poles. The number of pole pairs of the rotor 3 is the same as that of the magnets 23, and the number of pole pairs is “4” in the present embodiment. The number of segment conductors 14 straddling the teeth 12 is determined by (slot number / magnetic pole number).

  The magnet 23 of the rotor 3 is slightly longer in the circumferential direction than the first and second salient poles 31 and 32, and is formed in a substantially quadrangular prism shape having a curved outer surface 23a and a flat inner surface 23b. Yes. The outer surface 23a of the magnet 23 has an arc shape centered on the axis C, and is opposed to the distal end portion 12a of the tooth 12 in the radial direction. The magnet 23 has an inner surface 23 b fixed to a fixing surface 22 a provided between adjacent salient poles 31, 32 of the rotor core 22, and a circumferential gap is provided between the adjacent salient poles 31, 32. Yes. The magnets 23 are configured such that their outer side surfaces 23a are positioned on the same circumference.

  The first and second salient poles 31 and 32 have a shape that protrudes radially outward in a substantially fan shape, and have outer surfaces 31a and 32a that are curved. The first and second salient poles 31 and 32 are arranged so that the central portions thereof are equally spaced in the circumferential direction, and the outer surfaces 31a and 32a of the rotor 3 are opened about the axis C of the rotor 3. The angles Ykθ1 and Ykθ2 are formed to be different from each other. The open angles Ykθ1 and Ykθ2 of the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 are constant in the axial direction. Further, the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 are configured to be positioned on the same circumference, and are positioned relatively radially inward from the outer surface 23a of the magnet 23. Is configured to do.

  Here, when the open angle Ykθ1 of the first salient pole 31 of the rotor 3 (or the open angle Ykθ2 of the second salient pole 32) is changed, the cogging torque generated at the salient pole 31 (or salient pole 32) is changed. The boundary angle at which the phase inversion from the positive phase to the reverse phase is “α”, and the boundary angle at which the cogging torque is phase-inverted from the reverse phase to the positive phase is “β” (where α <β). One of the open angles Ykθ1 and Ykθ2 of the second salient poles 31 and 32 is set to a value less than the boundary angle α or larger than the boundary angle β, and the other is set to be greater than or equal to α and less than or equal to β. . That is, the open angles Ykθ1 and Ykθ2 of the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 are set so that the cogging torques generated at the first and second salient poles 31 and 32 are mutually phase-inverted. ing. Thereby, since the cogging torque generated at the first salient pole 31 is suppressed by the cogging torque generated at the second salient pole 32, the cogging torque can be more reliably reduced and the rotational performance of the rotor 3 can be improved. Can do.

  In the present embodiment, the opening angle around the axis C between the circumferential ends of the tip 12a of the tooth 12 is “Tθ (°)”, the number of the teeth 12 is “L (pieces)”, and the boundary angle α is “α = Tθ + (a−1) × 360 (°) / L” (where “a” is a natural number), and the boundary angle β is “β = α + 360 (°) / L”. In these numerical formulas, “360 (°) / L” is an angle centered on the axis C between the circumferential centers of the tips 12a of adjacent teeth 12 (in other words, between the circumferential centers of the gaps between the teeth 12). Angle around the axis C). That is, the right side of the mathematical formula “α = Tθ + (a−1) × 360 (°) / L” is an angle around the axis C at both ends in the circumferential direction of “a” teeth 12 continuous in the circumferential direction. Represents. That is, the boundary angle α is equal to the angle around the axis C of “a” teeth 12 continuous in the circumferential direction, and the boundary angle β is the axis C of “a + 1” teeth 12 continuous in the circumferential direction. Is equal to the angle centered at.

  Here, FIG. 4 shows the case of “a = 4”. In this case, the boundary angle α is an angle at both ends in the circumferential direction of the four teeth 12 continuous in the circumferential direction, and the boundary angle β is the circumferential direction. It is the angle of the circumferential direction both ends of the five teeth 12 which follow. In this embodiment, the open angle Ykθ2 of the outer surface 32a of the second salient pole 32 is set to be equal to or smaller than the boundary angle α, and the open angle Ykθ1 of the outer surface 31a of the first salient pole 31 is equal to or greater than the boundary angle α. It is set below β. Thereby, the open angles Ykθ1 and Ykθ2 of the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 are set so that the cogging torques generated at the first and second salient poles 31 and 32 are phase-inverted with each other. Has been.

  In the stator 2 of the present embodiment, the number of magnets 23 (the number of pole pairs) of the rotor 3 is “p” (where p is an integer of 2 or more), the number of phases of the segment winding 13 is “m”, and the teeth 12 The number “L” is “L = 2 × p × m × n (pieces)” (where “n” is a natural number). In this embodiment, the number “L” of teeth 12 is set to L = 2 × 4 (number of magnets 23) × 3 (number of phases) × 2 = 48 (pieces) based on this mathematical expression. Yes. The opening angle Tθ of the teeth 12 is set to 7 (°). That is, in this embodiment, the boundary angle α is 29.5 (°), the boundary angle β is 37 (°) (see FIG. 2), and the open angle Ykθ2 of the outer surface 32a of the second salient pole 32 is The opening angle Ykθ1 of the outer surface 31a of the first salient pole 31 is set to 29.5 (°) or more and 37 (°) or less, respectively, less than 29.5 (°).

  Further, it is desirable that the opening angles Ykθ1 and Ykθ2 of the first and second salient poles 31 and 32 are set so that the amplitudes of the cogging torque generated at the first and second salient poles 31 and 32 are close to each other. . For example, as shown in FIGS. 2 and 3, the open angle Ykθ1 of the first salient pole 31 is set to about 31.7 (°), and the open angle Ykθ2 of the second salient pole 32 is set to about 28.8 (°). For example, the cogging torques generated at the first and second salient poles 31 and 32 are mutually reversed in phase and substantially equal in amplitude. In this case, the cogging torque generated by the first and second salient poles 31 and 32 substantially cancels each other, and the cogging torque of the entire motor 1 (the synthesized cogging torque generated by the first and second salient poles 31 and 32). Therefore, the solid line waveform in FIG. 3 can be kept small.

  Furthermore, in the present embodiment, the open angle Ykθ2 of the outer surface 32a of the second salient pole 32 is set to be less than the boundary angle α, and the open angle Ykθ1 of the outer surface 31a of the first salient pole 31 is equal to or greater than the boundary angle α. And {(α + β) / 2} or less. That is, the opening angle Ykθ1 of the first salient pole 31 is set to be greater than the boundary angle α and the middle angle of the boundary angles α and β within the range of the boundary angle α and the boundary angle β. Thus, the circumferential interval between the first and second salient poles 31 and 32 and the magnet 23 is increased while the cogging torque phases generated at the first and second salient poles 31 and 32 are reversed. Therefore, it is possible to suppress the leakage magnetic flux resulting from the narrow circumferential interval between the first and second salient poles 31 and 32 and the magnet 23.

Next, characteristic effects of the present embodiment will be described.
(1) The center portions of the plurality of salient poles of the rotor 3 are arranged at equal intervals in the circumferential direction, and the opening angles Ykθ1 and Ykθ2 of the outer surfaces 31a and 32a centering on the axis C of the rotor 3 Includes a first salient pole 31 (first salient pole portion) and a second salient pole 32 (second salient pole portion). As a result, the timing at which the cogging torque is generated at the first and second salient poles 31 and 32 is shifted, so that the cogging torque generated in the entire motor 1 can be reduced as compared with the configuration in which the salient pole opening angle is uniform. Thus, the rotational performance of the rotor 3 can be improved.

  (2) One of the open angles Ykθ1 and Ykθ2 of the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 is set to be less than the boundary angle α or larger than the boundary angle β, and the other is the boundary angle It is set to be not less than α and not more than the boundary angle β. Thereby, the open angles of the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 are set so that the cogging torques generated at the first and second salient poles 31 and 32 are phase-inverted with each other. Therefore, since the cogging torque generated at the first salient pole 31 is suppressed by the cogging torque generated at the second salient pole 32, the cogging torque can be more reliably reduced.

  (3) One of the open angles Ykθ1 and Ykθ2 of the outer surfaces 31a and 32a of the first and second salient poles 31 and 32 is set to be less than the boundary angle α, and the other is greater than or equal to the boundary angle α and { It is set to (α + β) / 2} or less. That is, one of the open angles Ykθ1 and Ykθ2 is set to be less than the boundary angle α, and the other is within the range of the boundary angle α and the boundary angle β. Is set to an angle of Thus, the circumferential interval between the first and second salient poles 31 and 32 and the magnet 23 is increased while the cogging torque phases generated at the first and second salient poles 31 and 32 are reversed. Therefore, it is possible to suppress the leakage magnetic flux caused by the narrow interval between the first and second salient poles 31 and 32 and the magnet 23 in the circumferential direction.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the opening angle Ykθ2 of the second salient pole 32 is set to be less than the boundary angle α, and the opening angle Ykθ1 of the first salient pole 31 is set to be not less than α and not more than {(α + β) / 2}. This is not particularly limited. For example, the opening angles Ykθ1 and Ykθ2 of the first and second salient poles 31 and 32 may be appropriately changed to an angle outside the above range so as to be different from each other.

  Further, for example, even if the opening angle Ykθ2 of the second salient pole 32 is set larger than the boundary angle β, the phases of the cogging torque generated at the first and second salient poles 31 and 32 can be reversed. In the configuration in which the opening angle Ykθ2 of the second salient pole 32 is set larger than the boundary angle β, the opening angle Ykθ1 of the first salient pole 31 is set to {(α + β) / 2} or more and to the boundary angle β or less. It is possible to reduce the circumferential interval between the first and second salient poles 31 and 32 and the magnet 23 while reversing the phases of the cogging torque generated at the first and second salient poles 31 and 32. It becomes. For this reason, it is possible to suppress a reduction in torque resulting from a wide circumferential interval between the first and second salient poles 31 and 32 and the magnet 23.

  In the above embodiment, “a = 4” is used in the formula “α = Tθ + (a−1) × 360 (°) / L”, but “a” may be appropriately changed to a natural number other than 4. That is, for example, the angles at the circumferential ends of the three teeth 12 that are continuous in the circumferential direction may be the boundary angle α, and the angles at the circumferential ends of the four teeth 12 that are continuous in the circumferential direction may be the boundary angle β. . Thus, even when “a” is other than 4, the same effect as that of the above embodiment can be obtained.

  In the above embodiment, the number “L” of the teeth 12 is set to 60 (pieces) based on the formula “L = 2 × p × m × n (pieces)” (where “n” is a natural number). The number L of the teeth 12 may be changed by appropriately changing the number “p” of the magnets 23, the number of phases “m” of the segment windings 13, and the natural number “n” in this equation.

In the said embodiment, although the 1st salient pole 31 (1st salient pole part) and the 2nd salient pole 32 (2nd salient pole part) were arranged in the circumferential direction, it is not specifically limited to this.
For example, as shown in FIGS. 5A, 5 </ b> B, and 5 </ b> C, the first rotor core R <b> 1 in which the first salient poles 41 having the outer surface 41 a with the open angle Ykθ1 are formed between the magnets 23 at equal intervals in the circumferential direction. And the second salient pole 42 having the outer surface 42a with the open angle Ykθ2 and the second rotor core R2 formed between the magnets 23 at equal intervals in the circumferential direction may be laminated in the axial direction to constitute the rotor 3. (Tandem structure). Even in such a configuration, it is possible to obtain the same effect as in the above embodiment. In the example shown in FIG. 5, the rotor 3 has a two-stage configuration including the first rotor core R1 and the second rotor core R2. For example, the rotor 3 shown in FIG. 6 has a three-stage configuration, in which the rotor cores at both ends in the axial direction are each constituted by a first rotor core R1, and the rotor core at the center in the axial direction is constituted by a second rotor core R2. In the case of the multi-stage configuration shown in FIGS. 5 and 6, it may be configured by an odd number of pole pairs (that is, the number of magnets 23 is an odd number) such as 10 magnetic poles and 14 magnetic poles.

  Further, salient poles having different open angles at the axial positions may be provided without making the salient pole open angle constant in the axial direction. For example, in the rotor 3 shown in FIGS. 7A, 7B, 7C, and 7D, the salient poles 51 between the magnets 23 are shaped to taper in the axial direction. The opening angle is the opening angle Ykθ1 on the axial end 1a side of the rotor 3. The opening angle becomes smaller toward the other axial end 3 b of the rotor 3, and becomes the opening angle Ykθ2 on the other axial end 3 b side of the rotor 3. That is, each salient pole 51 has a first salient pole part and a second salient pole part having different opening angles in the axial direction. Even with such a configuration, it is possible to obtain the same effects as those of the above-described embodiment.

  In the example shown in FIG. 7, the opening angle of the salient pole 51 is configured to be the maximum at the one axial end 3a and the minimum at the other axial end, but other than this, for example, FIG. As shown in FIG. 6, the minimum may be configured at the center in the axial direction and the maximum may be achieved at both ends in the axial direction. On the other hand, as shown in FIG. 8B, it may be configured such that it is maximum at the center in the axial direction and minimum at both ends in the axial direction. Further, as shown in FIG. 9, the rotor core 22 may have a multi-stage configuration, and the opening angle may be changed for each stage.

  In the above embodiment, the winding of the stator 2 is the segment winding 13, but is not particularly limited thereto. For example, in the motor 1 a shown in FIG. 10, the number L of teeth 12 is configured to be “L = p × m (pieces)”. In FIG. 10, L = 4 (number of magnets 23) × 3 ( The number of phases) is set to 12 (pieces). A winding M made of a conducting wire (continuous wire) is wound around each tooth 12. In such a motor 1a, the magnetic poles (eight magnetic poles) of the rotor 3 are 2/3 times the number of teeth 12 (12), and the ratio of the magnetic poles of the rotor 3 to the number of teeth 12 is 2: There are three relationships.

  DESCRIPTION OF SYMBOLS 1,1a ... Motor, 2 ... Stator, 3 ... Rotor, 12 ... Teeth, 22 ... Rotor core, 23 ... Magnet, 31, 41 ... 1st salient pole (1st salient pole part), 31a, 32a, 41a, 42a, 51a ... outer side surface, 32, 42 ... second salient pole (second salient pole part), 51 ... salient pole, M ... winding, S ... slot, C ... axis, Yk [theta] 1, Yk [theta] 2 ... open angle, [alpha], [beta] ... Boundary angle.

Claims (5)

A plurality of magnets of one magnetic pole are arranged at equal intervals in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are arranged with gaps between the magnets so that the salient pole functions as the other magnetic pole. A rotor configured to
A motor including a core that is disposed on an outer peripheral side of the rotor, extends in a radial direction, and has a core having teeth provided at equal intervals in a circumferential direction and a multiphase winding attached to the teeth,
The plurality of salient poles are arranged such that their central portions are arranged at equal intervals in the circumferential direction, and the first salient pole portion and the second salient pole are different from each other in the open angle of the outer surface centering on the axis of the rotor. and a pole portion is configured Nde including,
The motor has a circumferential length larger than that of the first salient pole part and the second salient pole part . The motor according to claim 1,
When the open angle of the outer surface of the salient pole is changed, the boundary angle at which the cogging torque generated at the salient pole reverses from the positive phase to the opposite phase is defined as “α”, and the cogging torque is The boundary angle at which the phase is inverted from the phase to the positive phase is “β” (where α <β),
The open angle of one of the first and second salient pole portions is set to be less than the boundary angle α or larger than the boundary angle β, and the open angle of the other outer surface is set to the boundary A motor characterized by being set to an angle α or more and the boundary angle β or less. The motor according to claim 2,
The opening angle of the outer surface of one of the first and second salient pole portions is set to be less than the boundary angle α, and the opening angle of the other outer surface is equal to or greater than the boundary angle α and {( [alpha] + [beta]) / 2} or less. The motor according to claim 2,
The opening angle of one of the first and second salient pole portions is set to a value larger than the boundary angle β, and the opening angle of the other outer surface is {(α + β) / 2}. The motor is characterized by being set above and below the boundary angle β. The motor according to claim 1,
A motor, wherein the stator windings are distributed windings.

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