JP5513059B2 - Rotor and motor - Google Patents

Description

  The present invention relates to a rotor adopting a contiguous pole type structure and a motor including the rotor.

  As a rotor used in a motor, for example, as shown in Patent Document 1, a plurality of magnets having one magnetic pole are arranged in the circumferential direction of a rotor core, and salient poles formed integrally with the core are disposed between the magnets. A rotor having a so-called contiguous pole structure is known which is arranged and allows the salient pole to function as the other magnetic pole.

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 tends to occur, which leads to deterioration of rotational performance such as increased vibration.

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

  In order to solve the above problems, the invention according to claim 1 is characterized in that a plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, and the salient poles integrally formed with the rotor core have a gap between the magnets. A rotor arranged to function as a salient pole as the other magnetic pole, and among the gaps of the rotor with respect to the stator, the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side; The ratio B / A is set to 1 <B / A.

  In the present invention, the ratio B / A between the shortest air gap distance A on the magnet side and the shortest air gap distance B on the salient pole side among the air gaps of the rotor with respect to the stator is set to an appropriate value of 1 <B / A. The As a result, it is possible to reduce radial pulsation, rotor unbalance force, and torque ripple that cause vibration during rotor rotation (see FIGS. 3 to 5), which can contribute to improvement in the rotational performance of the rotor.

  According to a second aspect of the present invention, in the rotor according to the first aspect, a ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is 1.25 <B / The gist is that it is set within the range of A <1.6.

  In the present invention, the ratio B / A between the shortest air gap distance A on the magnet side and the shortest air gap distance B on the salient pole side is set in any of the ranges of 1.25 <B / A <1.6. Thereby, in addition to the reduction of radial pulsation, the rotor unbalance force can be effectively reduced (see FIG. 4), and the rotational performance of the rotor can be improved more reliably.

  According to a third aspect of the present invention, in the rotor according to the first aspect, the ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is 1 <B / A <. The gist is that it is set within the range of 1.55.

  In the present invention, the ratio B / A between the shortest air gap distance A on the magnet side and the shortest air gap distance B on the salient pole side is set to any one within the range of 1 <B / A <1.55. Thereby, in addition to the reduction of radial pulsation, torque ripple can be effectively reduced (see FIG. 5), and the rotational performance of the rotor can be improved more reliably.

  According to a fourth aspect of the present invention, in the rotor according to the third aspect, the ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is 1.15 <B / The gist is that it is set within the range of A <1.25.

  In the present invention, the ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set to any one of the ranges of 1.15 <B / A <1.25. Thereby, torque ripple can be reduced more effectively (see FIG. 5), and the rotational performance of the rotor can be improved more reliably.

  According to a fifth aspect of the present invention, in the rotor according to the first aspect, a ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is 1.2 <B / The gist is that it is set within the range of A <1.4.

  In the present invention, the ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set to any one of the ranges of 1.2 <B / A <1.4. Thereby, in addition to the reduction of radial pulsation, both the rotor unbalance force and the torque ripple can be effectively reduced (see FIGS. 4 and 5), and the rotational performance of the rotor can be improved more reliably.

  According to a sixth aspect of the present invention, in the rotor according to any one of the first to fifth aspects, the numbers of the magnets and the salient poles are set to odd numbers, and the magnet and the salient poles are 180 °. The gist is that they are arranged at opposite positions.

  In the present invention, the number of magnets and salient poles is an odd number, and the magnets and salient poles are arranged at positions opposite to each other by 180 °. That is, in the configuration in which the magnet and the salient pole are disposed at positions opposite to each other by 180 °, a magnetic imbalance tends to occur and the vibration during the rotor rotation tends to increase. It is significant to reduce the vibration by optimizing the air gap distance ratio B / A.

The invention according to claim 7 is a motor including the rotor according to any one of claims 1 to 6.
According to the present invention, it is possible to provide a motor in which the rotational performance with low vibration is improved by using the above-described rotor.

  According to the present invention, it is possible to provide a rotor capable of reducing vibration and improving rotational performance, and a motor including the rotor.

It is a top view of the motor in this embodiment. It is the elements on larger scale of the motor in the embodiment. It is a characteristic view which shows the relationship between the air gap distance ratio B / A and radial pulsation in the same embodiment. It is a characteristic view which shows the relationship between the air gap distance ratio B / A and rotor unbalance force in the same embodiment. It is a characteristic view which shows the relationship between the air gap distance ratio B / A and the torque ripple ratio in the same embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
1 and 2 show an inner rotor type brushless motor M. FIG. In the rotor 10 used in the motor M of the present embodiment, a substantially annular rotor core 12 made of a magnetic metal material is fixed to the outer peripheral surface of the rotating shaft 11, and an N-pole magnet is arranged in the circumferential direction of the outer peripheral portion of the core 12. 7 are arranged, and salient poles 12 a integrally formed on the outer periphery of the core 12 are arranged between the magnets 13. That is, the magnets 13 and the salient poles 12a are alternately arranged at equal angular intervals (in this case, the magnets 13 and the salient poles 12a are arranged at positions opposite to each other by 180 °). The salient pole 12a is a so-called continuous pole type having 14 magnetic poles that function as the S pole. The stator 20 is composed of 12 magnetic poles in which a coil 22 is wound around 12 teeth 21 a of a stator core 21.

  The magnet 13 of the rotor 10 is slightly longer in the circumferential direction than the salient pole 12a, and is formed in a substantially quadrangular prism shape having a flat inner side surface 13a and a curved outer side surface 13b. The inner surface 13a of the magnet 13 is fixed to a flat fixing surface 12b provided between adjacent salient poles 12a of the rotor core 12, and a circumferential gap S1 is provided between the adjacent salient poles 12a. The outer surface 13b of each magnet 13 is formed in a curved shape located on the same circumference.

  The salient poles 12a are slightly smaller than the gap S1 with the magnet 13, have a shape that protrudes radially outward in a substantially fan shape, and have an outer surface 12c that has a curved shape. The outer surface 12c of each salient pole 12a has a curved shape in which the central portion in the circumferential direction is relatively convex outward in the radial direction from both ends in the circumferential direction, in other words, from the circumferential central portion toward the circumferential end. It is formed in a curved shape that recedes radially inward in a curved manner. In addition, the curvature of the outer surface 12c is constant in each outer surface 12c, and is symmetrical from the circumferential center to both sides.

  Further, the outer surface 12c and 13b of the salient pole 12a and the magnet 13 are configured such that the outer surface 12c on the salient pole 12a side is positioned relatively radially inward from the outer surface 13b on the magnet 13 side. . That is, in the air gap S2 of the rotor 10 with respect to the stator 20 (the tip surface of the tooth 21a), the air gap distance B on the salient pole 12a side (in this case, the shortest air gap distance in the center in the circumferential direction) is the air gap distance A (circumference) on the magnet 13 side. The direction is constant, that is, it is set larger than the shortest gap distance in any circumferential direction.

  Here, when the ratio B / A of the gap distances B and A on the salient pole 12a side and the magnet 13 side with respect to the stator 20 is changed, the radial pulsation ratio is shown in FIG. 3, and the rotor unbalance force ratio is shown in FIG. The torque ripple ratio is shown in FIG. The radial pulsation, rotor unbalance force, and torque ripple are factors that increase vibration during rotation of the rotor 10, respectively.

  FIG. 3 shows the radial pulsation ratio when B / A is changed. B / A = 1, that is, the radial pulsation when the gap distances B and A on the salient pole 12a side and the magnet 13 side are the same. Is set to “1”, the radial pulsation decreases substantially from “1” as B / A increases (as the salient pole 12 a is positioned inside the magnet 13). Specifically, when B / A = 1.2, the radial pulsation is about “0.89”, and when B / A = 1.4, the radial pulsation is about “0.8”, and B / A = 1.6. In this case, the radial pulsation decreases to about “0.72”. That is, if 1 <B / A, reduction of radial pulsation can be expected.

  Next, FIG. 4 shows the rotor unbalance force ratio when B / A is changed. Similarly to the above, when the rotor unbalance force when B / A = 1 is set to “1”, the B / A As A increases, the rotor unbalance force decreases, and after a minimum value, starts to increase slightly. Specifically, the range from B / A = 1 to B / A = 1.4 is a range in which the rotor unbalance force decreases. The closer the B / A = 1.4, the smaller the range of decrease. /A=1.4 is the minimum value of about “0.3”. From B / A = 1.4 to B / A = 1.6, the rotor unbalance force increases slightly but increases to about “0.4” at B / A = 1.6. In other words, if 1 <B / A, the rotor unbalance force can be reduced at least until the measured B / A = 1.6, and particularly within the range of 1.25 <B / A <1.6, B / A = 1, approximately 40% or less of the rotor unbalance force at the time of / A = 1, and the effect of reducing the rotor unbalance force is great.

  Next, FIG. 5 shows the torque ripple ratio when B / A is changed. Similarly to the above, when the torque ripple when B / A = 1 is set to “1”, the B / A increases. As the torque ripple decreases, the torque ripple decreases and then increases again after passing through the minimum value. Specifically, the torque ripple decreases from B / A = 1 to B / A = 1.2, and the decreasing range gradually decreases as B / A = 1.2. = 1.2 is the minimum value of about “0.47”. From B / A = 1.2 to B / A = 1.6, the torque ripple is in an increasing range. From B / A = 1.2, the range of increase gradually increases, and B / A = 1. 55, the torque ripple is equivalent to B / A = 1. After B / A = 1.55, it increases as it is. In other words, if 1 <B / A <1.55, torque ripple can be expected to be reduced. Especially within the range of 1.15 <B / A <1.25, the torque ripple when B / A = 1 is an abbreviation. Less than half, and the effect of reducing torque ripple is great.

  Based on these, in the rotor 10 of the present embodiment, the ratio B / A of the gap distances B and A on the salient pole 12a side and the magnet 13 side with respect to the stator 20 is within the range of 1 <B / A <1.55. It is set to This makes it possible to reduce radial pulsation (Fig. 3), rotor unbalance force (Fig. 4), and torque ripple (Fig. 5) that lead to vibration during rotation of the rotor 10, and in particular to reduce the rotor unbalance force. B / A is set in the vicinity of “1.4” for those that do, and B / A is set in the vicinity of “1.2” for those that emphasize torque ripple reduction. Thus, in the present embodiment, each factor that leads to vibration during rotation of the rotor 10 is reduced, and the rotational performance of the rotor 10 is improved.

Next, characteristic effects of the present embodiment will be described.
(1) In this embodiment, the ratio B / A between the gap distance A on the magnet 13 side and the gap distance B on the salient pole 12a side in the gap S2 of the rotor 10 with respect to the stator 20 is 1 <B / A. Is set to an appropriate value. As a result, radial pulsation, rotor unbalance force, and torque ripple that cause vibrations during rotation of the rotor 10 can be reduced (see FIGS. 3 to 5), and the rotational performance of the rotor 10 can be improved. . That is, it can be provided as a motor M with improved rotational performance.

  Incidentally, by setting the ratio B / A of the gap distances A and B to any one of the ranges of 1.25 <B / A <1.6, the rotor unbalance force is effectively reduced in addition to the reduction of radial pulsation. Can be reduced.

  In addition to reducing radial pulsation, torque ripple can be effectively reduced by setting the ratio B / A of the air gap distances A and B to any value within the range of 1 <B / A <1.55. Can do. In this case, furthermore, the torque ripple can be further effectively reduced by setting the ratio B / A of the gap distances A and B to any of the ranges of 1.15 <B / A <1.25. .

  In addition to reducing radial pulsation, the rotor unbalance force and torque ripple can be reduced by setting the ratio B / A of the gap distances A and B to any value within the range of 1.2 <B / A <1.4. Both can be effectively reduced.

  (2) In the said embodiment, the number of the magnets 13 and the salient poles 12a is an odd number, and the magnets 13 and the salient poles 12a are disposed at positions opposite to each other by 180 °. That is, in the configuration in which the magnet 13 and the salient pole 12a are disposed at positions opposite to each other by 180 °, a magnetic imbalance tends to occur and the vibration during rotation of the rotor 10 tends to increase. It is significant to reduce the vibration by optimizing the ratio B / A of the gap distances A and B between the side and the salient pole 12a.

In addition, you may change embodiment of this invention as follows.
-You may change suitably the numerical range about the said embodiment according to a condition.
-About the said embodiment, you may change suitably the shape of both the outer side surfaces 12c and 13b of the salient pole 12a and the magnet 13. FIG. Although the outer surface 13b on the magnet 13 side has a curved shape having the same circumference and the outer surface 12c on the salient pole 12a side has a curved shape with a larger curvature, the reverse may be possible. Further, both the outer surfaces 12c and 13b may be curved with the same circumference, and both the outer surfaces 12c and 13b may be curved with a large curvature. Further, the curved shapes of the outer surfaces 12c and 13b are not limited to constant curvature, but may be shapes that change the curvature in the circumferential direction or shapes that change linearly.

Besides these, the shape of the magnet 13 and the shape of the rotor core 12 including the salient poles 12a may be changed as appropriate.
In the above embodiment, the present invention is applied to the 14-pole rotor 10 constituted by the seven salient poles 12a and the seven magnets 13. However, the number of magnetic poles may be changed as appropriate. Along with this, the number of magnetic poles on the stator 20 side is appropriately changed.

  In the above embodiment, the present invention is applied to the rotor 10 used for the inner rotor type motor M, but may be applied to the rotor of an outer rotor type motor. In this case, the opposing relationship in the radial direction between the rotor and the stator is reversed.

  DESCRIPTION OF SYMBOLS 10 ... Rotor, 12 ... Rotor core, 12a ... Salient pole, 13 ... Magnet, 20 ... Stator, S1, S2 ... Air gap, A, B ... Air gap distance (shortest air gap distance).

Claims (7)

A plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles function as the other magnetic poles. A rotor,
Of the rotor gaps with respect to the stator, the ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set to 1 <B / A. . The rotor according to claim 1, wherein
A ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set in a range of 1.25 <B / A <1.6. Rotor. The rotor according to claim 1, wherein
The rotor, wherein a ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set in a range of 1 <B / A <1.55. The rotor according to claim 3, wherein
A ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set in a range of 1.15 <B / A <1.25. Rotor. The rotor according to claim 1, wherein
A ratio B / A between the shortest gap distance A on the magnet side and the shortest gap distance B on the salient pole side is set in a range of 1.2 <B / A <1.4. Rotor. The rotor according to any one of claims 1 to 5,
The number of the magnets and the salient poles is set to an odd number, and the magnet and the salient poles are arranged at positions opposite to each other by 180 °.   A motor comprising the rotor according to claim 1.

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