JP2018107876A - Dual-stator motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dual-stator motor in which the space for the coil end of a distributed winding coil of one motor part is used as a space for arranging another motor part, whereby reduction in output density can be improved.SOLUTION: The dual-stator motor comprises: an inner rotor type first motor part 1including a first rotor 2and a first stator 3which is positioned radially outside the first rotor 2and which has a distributed winding coil 4attached therearound; and an outer rotor type second motor part 1including a second rotor 2which is connected to an axial end of the first rotor 2and which is positioned radially inside a coil end 4a of the distributed winding coil 4and a second stator 3which is positioned radially inside the second rotor 2and which has a concentrated winding coil 4attached therearound.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dual stator motor including two stators.

  The motor includes an inner rotor type composed of a rotor and a stator positioned radially outside the rotor, and an outer rotor type composed of a rotor and a stator positioned radially inside the rotor (for example, Patent Document 1).

  Further, there are concentrated winding coils and distributed winding coils as coils to be mounted on the stator. A concentrated winding coil is a single coil wound around one tooth of a stator, and the space of the coil end protruding outward in the axial direction of the stator is small, but the utilization factor of magnetic flux is smaller than that of a distributed winding coil. Inferior. On the other hand, the distributed winding coil is obtained by winding one coil across a plurality of teeth of the stator, and the utilization rate of the magnetic flux is improved, but the space of the coil end extending outward in the axial direction of the stator becomes large. .

  Here, the coil end is a portion that does not contribute to torque. Therefore, in a motor including a stator equipped with distributed winding coils, it is desired to improve a decrease in output density due to a coil end space.

JP 2008-61485 A

  In view of the above points, the present invention provides a dual stator motor that can improve the reduction in output density by utilizing the space of the coil end of the distributed winding coil of one motor unit as the arrangement space of another motor unit. The issue is to provide.

  In order to solve the above-described problems, the present invention provides an inner rotor type first motor unit that includes a first rotor and a first stator that is mounted on the radially outer side of the first rotor and on which distributed winding coils are mounted. A second rotor connected to the shaft end of the first rotor and positioned radially inward of the coil end of the distributed winding coil; and a second stator mounted with concentrated winding coils positioned radially inward of the second rotor; And an outer rotor type second motor section.

  According to the present invention, the space of the coil end of the distributed winding coil attached to the first stator that is a component of the first motor unit can be utilized as the arrangement space of the second motor unit. Therefore, the decrease in output density due to the coil end space of the distributed winding coil can be improved by the second motor unit.

  By the way, in order to reduce the cost, it is desired that the first rotor and the second rotor have a common rotor core formed by stacking annular core plates having the same shape. In this case, a permanent magnet is embedded in a portion near the outer periphery of the portion that becomes the first rotor of the rotor core, and the first motor portion is configured by a permanent magnet synchronous motor, and the portion near the inner periphery of the portion that becomes the second rotor of the rotor core. It is conceivable that a permanent magnet is embedded in the portion, and the second motor unit is also composed of a permanent magnet synchronous motor. However, this requires an increase in the radial thickness of the rotor core, which increases the diameter of the motor.

  Therefore, when the first rotor and the second rotor have a common rotor core formed by stacking annular core plates having the same shape, the first rotor and the second rotor are permanently attached to the outer peripheral portion of the portion that becomes the first rotor of the rotor core. A magnet is embedded, and the first motor part is constituted by a permanent magnet synchronous motor. On the other hand, a groove for imparting saliency is provided on an inner peripheral surface including a portion to be the second rotor of the rotor core, and the second motor part is provided. It is desirable to configure with a reluctance synchronous motor. According to this, it is not necessary to increase the radial thickness of the rotor core, and the motor can be prevented from increasing in diameter.

The perspective view of the part cut to the circumferential direction 1/4 and the axial direction 1/2 of the principal part of the dual stator motor of embodiment of this invention. The perspective view seen from the opposite direction of FIG. Explanatory drawing which shows magnetic flux distribution of the permanent magnet which flows into a rotor core at the time of no load of the dual stator motor of embodiment.

Referring to FIGS. 1 and 2, the dual stator motor embodiment of the present invention includes a first motor part 1 ₁ of the inner rotor type, and a second motor section 1 ₂ of the outer rotor type. The first motor section _{1 1} is composed of first and rotor _{2 1,} the first stator _{3 1} Metropolitan located radially outward of the first rotor _{2 1.}

The first stator 3 _1, distributed winding coil 4 ₁ wrapped with one coil over a plurality of teeth 3 _{1 a} of the stator 3 ₁ is mounted. Here, the coil end 4 _{1 a} of the distributed winding coil 4 ₁ out largely Zhang from the first stator 3 ₁ axially outward. The coil end 4 _{1 a} are the portions that do not contribute to torque, with only the first motor section 1 _1, the output density decreases by the space of the coil end 4 _{1 a.}

The second motor section 1 ₂ is connected to the first rotor 2 _first shaft end, the second rotor 2 ₂ located radially inside the coil end 4 _{1 a} of the distributed winding coil 4 _1, the second rotor 2 comprising a second stator 3 ₂ which is located radially inward of _2. The second stator 3 _2, concentrated winding coil 4 ₂ wrapped with one coil in one of the teeth 3 _{2 a} of the stator 3 ₂ is mounted.

According to this, you can take advantage of the distributed winding coil 4 ₁ of the coil end 4 _{1 a} space for mounting the first stator 3 ₁ to the second motor section 1 ₂ of arrangement space. Therefore, a reduction in power density by distributed winding coil 4 ₁ of the coil end 4 _{1 a} space can be improved by the second motor unit 1 _2.

Further, in the present embodiment, the first rotor 2 ₁ and the second rotor 2 _2, have a common rotor core 21 formed by laminating the core plates annular same shape (not shown). Incidentally, the rotor core 21, the inner circumference of the first rotor 2 ₁ become part, is connected to the rotary shaft 6 of the motor via a spacer 5. The spacer 5 may be a magnetic material or a non-magnetic material.

In the portion near the outer periphery of the rotor core 21, a plurality of magnet insertion holes 21 a configured by continuous holes formed in the core plate are provided at intervals in the circumferential direction. Then, the outer peripheral side of the portion of the first rotor 2 ₁ become part of the rotor core 21, are embedded the permanent magnet 22 in a state of being inserted in each magnet insertion hole 21a. Thereby, the 1st motor part ₁₁ is comprised with a permanent magnet synchronous motor. Incidentally, buried portions of the permanent magnet 22 is limited to areas of the first rotor 2 ₁ of the rotor core 21.

The inner peripheral surface including a second rotor 2 ₂ become part of the rotor core 21, and by continuously forming the notches in the core plate, a groove 21b to impart saliency resides a circumferential spacing Are provided. Thus, the second motor section 1 ₂ is composed of a reluctance synchronous motor.

  As is apparent from FIG. 3 showing the magnetic flux distribution of the permanent magnet 22 flowing through the rotor core 21 when there is no load, the groove 21b is formed in a portion where the magnetic flux density is low, that is, in the radial direction of the central portion in the circumferential direction of each permanent magnet 22. Is provided. Thereby, the influence of the groove 21b on the magnetic flux of the permanent magnet 22 flowing through the rotor core 21 can be minimized.

Meanwhile, the first rotor 2 ₁ shaft end, which The Although it is possible to connect the second rotor 2 ₂ separate, cost increases in this. In contrast, in the present embodiment, since it is assumed to have a first rotor 2 ₁ a common rotor core 21 constituted a second rotor 2 ₂ by laminating core plates of the same shape, it is possible to reduce the costs it can.

In this case, the inner peripheral portion close to the second rotor 2 ₂ become part of the rotor core 21 is embedded a second permanent magnet, the same permanent magnet synchronous motor and the second motor section 1 ₂ and the first motor section 1 ₁ It is also possible to configure with However, in this case, it is necessary to increase the radial thickness of the rotor core 21 to secure a space for embedding the second permanent magnet, and the motor has a large diameter. On the other hand, in this embodiment, since only the groove 21b is provided on the inner peripheral surface of the rotor core 21, it is not necessary to increase the radial thickness of the rotor core 21, and the motor can be prevented from increasing in diameter.

Further, in the permanent magnet synchronous motor, the counter electromotive voltage induced in the coil in the high rotation range becomes large and cannot be rotated at a predetermined rotation speed or higher. On the other hand, the reluctance synchronous motor has a smaller output torque than the permanent magnet synchronous motor, but can be rotated stably even in a high rotation range. Therefore, to connect each separate driving circuit (inverter) to the second motor section 1 ₂ formed of the first motor section 1 ₁ and the reluctance synchronous motor consists of a permanent magnet synchronous motor, low and medium speed required torque in the rotation zone drives the first motor section 1 _1, in a high speed region that does not require a not that much torque may be driven a second motor unit 1 _2.

As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this, A various change can be implemented in the range which does not deviate from the meaning of this invention. For example, FIGS. 1 and 2 show only one half of the motor in the axial direction, so there is only one _second motor part 12, but the coil of the distributed winding coil in the other half of the motor in the axial direction. It is possible to provide the second motor portion also on the radially inner side of the end.

DESCRIPTION OF SYMBOLS 1 ₁ ... 1st motor part, 1 ₂ ... 2nd motor part, 2 ₁ ... 1st rotor, 2 ₂ ... 2nd rotor, 21 ... Rotor core, 21b ... Groove, 22 ... Permanent magnet, 3 ₁ ... 1st stator, 3 ₂ ... second stator, 4 ₁ ... distributed winding coil, 4 ₁ a ... coil end, 4 ₂ ... concentrated winding coil.

Claims (2)

  A first rotor and an inner rotor type first motor unit that is located on the radially outer side of the first rotor and that is equipped with a distributed stator coil and that is connected to the shaft end of the first rotor. An outer rotor type second motor portion comprising a second rotor located radially inside the coil end of the wound coil and a second stator fitted with concentrated winding coils located radially inside the second rotor. A dual stator motor comprising:   The first rotor and the second rotor have a common rotor core configured by stacking annular core plates having the same shape, and a permanent magnet is embedded in a portion near the outer periphery of the portion that becomes the first rotor of the rotor core, The first motor unit is constituted by a permanent magnet synchronous motor, the groove for imparting saliency is provided on the inner peripheral surface including the portion to be the second rotor of the rotor core, and the second motor unit is constituted by a reluctance synchronous motor. The dual stator motor according to claim 1.

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