JP2010279157A - Permanent magnet type rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet type rotating electric machine attaining cost reduction by saving resources to acquire a desired torque, by optimizing for obtaining a high torque using few magnets. <P>SOLUTION: The permanent magnet type rotating machine includes a stator 3 wound with an excitation coil 6, and a rotor 4 rotating opposite with a predetermined gap from the stator 3. In the rotating machine, the rotor 4 includes a surface magnet portion 13, in which permanent magnets 21 are disposed so as to protrude to have different polarities adjacent in the circumferential direction on the surface of a rotor core 12, and an embedded magnet portion 14, in which slots 31 penetrating through the shaft direction inside the rotor core 12 are provided corresponding to the permanent magnets 21 of the surface magnet portion and permanent magnets 32 are inserted into the slots 31 so as to have the same polarity as that of the surface magnet portion 13. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a permanent magnet type rotating machine that includes a stator and a rotor that rotates oppositely with a predetermined gap.

Conventional permanent magnet type rotating machines are roughly classified into surface magnet type rotating machines and embedded magnet type rotating machines.
A surface magnet type rotating machine is a rotating machine that uses a magnet torque generated by sticking a magnet to the rotor surface, and the magnetic flux generated from the magnet is generated according to the amount of magnetic flux linkage with the exciting coil provided in the stator. It is widely used mainly for servo rotating machines because of its responsiveness.

On the other hand, an embedded magnet type rotating machine is a rotating machine that has a permanent magnet inside the rotor and uses reluctance torque using the magnetic resistance of the rotor core in addition to the magnet torque described above. The gap between the rotor and the rotor can be made narrower than that of a surface magnet type rotary machine, and it is widely used as a small high-power rotary machine.
One method of increasing the torque in this embedded magnet type rotating machine is to increase the magnet torque by increasing the amount of magnets. However, due to the recent increase in magnet prices, there is a problem in that the cost for manufacturing a rotating machine increases significantly.

  In order to solve the above problems, conventionally, a permanent magnet is embedded in the rotor, and a permanent magnet is embedded in the inner peripheral surface of the rotor, and the magnet torque is increased by a small amount of permanent magnets, thereby increasing the torque of the rotating machine. Measures have been proposed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2003-61280

However, the conventional example described in Patent Document 1 has a configuration in which the permanent magnet is embedded in the rotor and the permanent magnet is embedded in the surface of the rotor. There is an unsolved problem that magnetic saturation is likely to occur in the iron core constituting the rotor core between the permanent magnets, and the torque performance at the time of high output deteriorates.
Therefore, the present invention has been made by paying attention to the unsolved problems of the above-described conventional example, and suppresses magnetic saturation on the outer peripheral surface of the rotor so that a high torque can be obtained with a small amount of magnets. The purpose is to provide a rotating machine.

In order to achieve the above object, a permanent magnet type rotating machine according to an embodiment of the present invention includes a stator around which an exciting coil is wound, and a rotor that rotates opposite to the stator with a predetermined gap therebetween. A permanent magnet type rotary machine with
The rotor has a surface magnet portion in which permanent magnets are arranged on the surface of the rotor core so as to protrude in the circumferential direction so as to have different polarities, and
A slot penetrating the rotor core in the axial direction in correspondence with the permanent magnet of the surface magnet portion, and an embedded magnet portion having a permanent magnet inserted into the slot so as to have the same polarity as the surface magnet portion; It is characterized by having.

A permanent magnet type rotating machine according to another embodiment of the present invention is characterized in that the slot is divided into a plurality of slots, and permanent magnets having the same polarity are inserted into the divided slots.
Furthermore, in the permanent magnet type rotating machine according to another aspect of the present invention, the slot is divided into two, and the divided slot is arranged in a V shape that is convex with respect to the center of rotation when viewed from the end surface in the axial direction. The permanent magnet of the same polarity is inserted into each of the divided slots.

  According to the present invention, the rotor penetrates the rotor core in the axial direction, and the surface magnet portion in which the permanent magnets are protruded from the surface of the rotor core so as to have different polarities adjacent to each other in the circumferential direction. A slot to be provided corresponding to the permanent magnet of the surface magnet portion, and an embedded magnet portion into which the permanent magnet is inserted so as to have the same polarity as the surface magnet portion. The high torque performance of the surface magnet type rotating machine can be realized. In addition, since the embedded magnet part that inserts the permanent magnet into the slot provided inside the rotor is configured together with the surface magnet part, reluctance torque can be used in addition to the magnet torque. Together with the torque, the torque of the entire rotating machine can be increased. In addition, since the surface magnet portion only needs to be arranged with the permanent magnet protruding from the outer peripheral surface of the rotor core, the assembly can be easily performed and the rigidity of the permanent magnet is not lowered.

It is sectional drawing which shows the permanent magnet type rotary machine which shows the 1st Embodiment of this invention. FIG. 2 is an axial end view showing the rotor of FIG. 1. It is sectional drawing on the AA line of FIG. It is sectional drawing which shows the permanent-magnet-type rotary machine which shows the 2nd Embodiment of this invention. It is sectional drawing which shows the permanent-magnet-type rotary machine which shows the 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention. In FIG. 1, a permanent magnet type rotating machine 1 has a cylindrical frame 2. A stator 3 is disposed on the inner peripheral side of the cylindrical frame 2, and a rotor 4 is disposed on the inner peripheral side of the stator 3 with a predetermined air gap G therebetween. The rotor 4 is supported by a rotating shaft 5 and is rotatably arranged.

  In the stator 3, 12 slots 6 are formed at equal intervals in the circumferential direction on the inner peripheral surface side, and 12 magnetic teeth 7 are formed. An exciting coil 8 wound in the slot 6 is wound around each magnetic pole tooth 7. Here, the winding method of the exciting coil 8 is roughly classified into concentrated winding and distributed winding. The present invention exhibits effects in both concentrated winding and distributed winding, and the winding method is not limited by FIG.

On the other hand, the rotor 4 includes a rotor core 12 formed of a laminated iron core, a surface magnet portion 13 disposed on the outer peripheral surface of the rotor core 12, and a rotor core, as shown in an enlarged view in FIG. 12 and an embedded magnet portion 14 disposed in the interior.
The surface magnet portion 13 has four circular arc-shaped permanent magnets 21 having an inner peripheral surface having the same curvature as the outer peripheral surface of the rotating core 12 at equal intervals in the circumferential direction and with a predetermined gap therebetween. The rotating core 12 has a configuration in which the outer surface protrudes outward from the outer peripheral surface. Here, each permanent magnet 21 is integrally formed by sintering rare earth magnet powder, and the outer peripheral surfaces of adjacent permanent magnets 21 are magnetized with different polarities. Each permanent magnet 21 is attached to the outer peripheral surface of the rotor core 12 with an adhesive or the like.

  Further, the embedded magnet portion 14 is formed in the rotor core 12 at a position corresponding to each permanent magnet 21 of the surface magnet portion 13 so as to extend perpendicular to the radial direction and to have a slot 31 penetrating in the axial direction. In each slot 31, a permanent magnet 32 magnetized in the same direction as the permanent magnet 21 of the surface magnet portion 13 is inserted and fixed by an adhesive or a filler. Here, the permanent magnet 32 is also integrally formed by sintering rare earth magnet powder in the same manner as the permanent magnet 21 described above.

  Thus, according to the first embodiment, since the rotor 4 of the permanent magnet type rotating machine 1 has the surface magnet portion 13 and the embedded magnet portion 14, the permanent magnet 21 of the surface magnet portion 13 of the rotor 4. A line connecting the central portion in the circumferential direction and the axis of the rotary shaft 5 is the d-axis. A line connecting between the permanent magnets 21 having different polarities of the surface magnet portion 13 and the axis of the rotary shaft 5 is the q axis. For this reason, the permanent magnet 14 having the same magnetic resistance as the air gap G exists in the magnetic path of the magnetic flux in the d-axis direction, and the magnetic flux does not easily pass, but the magnetic flux in the q-axis direction can pass through the rotor core 12. Therefore, the magnetic resistance in this direction is reduced, and the d-axis inductance Ld and the q-axis inductance Lq have saliency Ld <Lq. For this reason, the self-inductance and mutual inductance of the armature winding change at twice the rotation angle, and the armature linkage magnetic flux of the permanent magnet also changes at the cosine of the rotation angle of the rotor 4.

  Therefore, the torque can be increased by adding the reluctance torque to the magnet torque. Here, the magnet torque is a torque generated by energy conversion due to a change in only the armature linkage magnetic flux of the permanent magnet. The reluctance torque is a torque generated by converting magnetic energy stored in the air gap G into mechanical energy in accordance with changes in the armature self and mutual inductance.

Thus, since the surface magnet portion 13 and the embedded magnet portion 14 are formed in the rotor core 12 as the rotor 4 of the permanent magnet type rotating machine 1, the surface magnet type rotating machine is formed by the surface magnet portion 13. High torque performance can be exhibited.
Further, since the permanent magnet 32 is inserted and fixed in the slot 31 provided inside the rotor core 12 together with the surface magnet portion 13, the reluctance is added to the magnet torque as described above. Torque can also be used, and combined with the magnet torque of the surface magnet portion 13, the torque of the entire rotating machine can be increased.

  Further, since the surface magnet unit 13 fixes the permanent magnet 21 directly on the outer peripheral surface of the rotor core 12 with a predetermined gap in the circumferential direction using an adhesive or the like, it is permanent as in the conventional example described above. Since the core of the rotor core is not interposed between the magnets and is not affected by magnetic saturation, the torque performance is not deteriorated. Further, the surface magnet portion 13 can be easily assembled and does not require great rigidity because no external force acts on the permanent magnet 21. Furthermore, since the permanent magnet 21 is fixed to the outer peripheral surface of the rotor core 12, the surface area of the outer peripheral surface of the permanent magnet 21 can be increased as compared with the conventional example described above.

  Incidentally, a ring-shaped metal in which a plurality of sintered magnets are arranged in a V shape in the rotor core so that the outer peripheral end portion protrudes from the rotary core, and the outer peripheral end portions protruding from the rotor core are laminated. Although it is conceivable to cover the magnet with a magnet, in this case, the assembly of the rotor becomes complicated. In addition, since the ring-shaped metal magnet supports the sintered magnet, it requires a large rigidity and has a problem that a large magnet torque cannot be obtained because a rare earth magnet cannot be used. However, in the first embodiment, since the surface magnet portion 13 is directly formed on the outer peripheral surface of the rotor core 12, it is necessary to obtain a large magnet torque and to support the embedded magnet portion 14 with the permanent magnet 21. There is no need for great rigidity.

Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, the configuration of the embedded magnet portion 14 in the first embodiment described above is changed.
That is, in the second embodiment, as shown in FIG. 4, the slot 31 of the embedded magnet portion 14 in the first embodiment described above is divided to form two slots 31a and 31b. Permanent magnets 32a and 32b are inserted into 31b and fixed with an adhesive or a filler.

  According to the second embodiment, the slot 31 of the embedded magnet portion 14 is divided into two, and the permanent magnets 32a and 32b are inserted into the slots 31a and 31b and fixed by an adhesive, a filler, or the like. As in the machine, the centrifugal force applied to the permanent magnets 32a and 32b at the time of rotation can be alleviated, and magnet breakage due to the centrifugal force can be prevented.

Next, a third embodiment of the present invention will be described with reference to FIG.
In the third embodiment, the configuration of the embedded magnet portion 14 in the second embodiment described above is changed.
That is, in the third embodiment, as shown in FIG. 5, the slots 31 a and 31 b of the embedded magnet portion 14 are V-shaped so that their adjacent end portions protrude toward the rotation center side of the rotor core 12. The permanent magnets 32a and 32b are inserted into the slots 31a and 31b and fixed with an adhesive, a filler or the like.

According to the third embodiment, since the divided slots 31a and 31b are arranged in a V shape, the reluctance torque can be increased and the torque of the entire rotating machine can be increased. The magnets 32a and 32b can be made small, and an inexpensive permanent magnet type rotating machine can be provided.
In the third embodiment, the case where the eight slots 31a and 31b are formed in the rotor 4 has been described. However, the present invention is not limited to this. By forming the slot itself in a V shape, The number of slots can be halved.

  In the first to third embodiments, the case where the number of magnetic poles of the rotor 4 is four and the number of magnetic pole teeth 7 of the stator 3 is twelve has been described. However, it is not limited to the said structure, The number of magnetic poles of the rotor 4 and the number of teeth of the stator 3 can be set arbitrarily.

  DESCRIPTION OF SYMBOLS 1 ... Permanent magnet type rotary electric machine, 2 ... Cylindrical frame, 3 ... Stator, G ... Air gap, 4 ... Rotor, 5 ... Rotating shaft, 6 ... Slot, 7 ... Magnetic pole teeth, 8 ... Excitation coil, 11 ... Magnetic pole, 12 ... Rotor core, 13 ... Surface magnet part, 14 ... Embedded magnet part, 21 ... Permanent magnet, 31, 31a, 31b ... Slot, 32, 32a, 32b ... Permanent magnet

Claims (3)

A permanent magnet type rotating machine comprising a stator around which an exciting coil is wound, and a rotor that rotates in opposition to the stator across a predetermined gap,
The rotor has a surface magnet portion in which permanent magnets are arranged on the surface of the rotor core so as to protrude in the circumferential direction so as to have different polarities, and
A slot that passes through the rotor core in the axial direction in correspondence with the permanent magnet of the surface magnet portion, and an embedded magnet portion in which the permanent magnet is inserted so as to have the same polarity as the surface magnet portion. A permanent magnet type rotating machine comprising:   The permanent magnet type rotating machine according to claim 1, wherein the slot is divided into a plurality of slots, and a permanent magnet having the same polarity is inserted into each of the divided slots.   The slot is divided into two, and the divided slots are arranged in a V shape that is convex with respect to the center of rotation when viewed from the axial end face, and permanent magnets of the same polarity are inserted into the divided slots. The permanent magnet type rotating machine according to claim 1.

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