JP3417409B2 - Electric motor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synchronous motor having a stator that generates a rotating magnetic field and rotationally driven by utilizing reluctance torque.

[0002]

2. Description of the Related Art In a conventional general synchronous motor, a stator integrally projects a plurality of teeth portions from a ring-shaped yoke portion on the inner peripheral side thereof. It should be noted that this stator is made by stacking stator plates each having a plurality of teeth that project inward. Further, these have a stator core having a slot formed between the teeth,
A winding is distributedly wound around the slot. The distributed winding is a winding method of winding the teeth portion apart from each other via the slot portion. The rotor is configured by embedding a plurality of permanent magnets for magnetic poles in the outer peripheral portion of the rotor core and fitting the rotating shaft in the central portion.

As described above, by embedding the permanent magnet inside the rotor, the permanent magnet embedded motor capable of utilizing not only the magnet torque but also the reluctance torque is arranged in the direction connecting the center of the permanent magnet and the center of the rotor. There d
Inductance Ld in the axial direction and inductance L in the q-axis direction, which is a direction rotated by an electrical angle of 90 degrees with respect to the d-axis
An inductance difference is generated in d, and reluctance torque is generated in addition to the magnet torque generated by the permanent magnet. Equation (1) shows this relationship. T = Pn [ψa × Iq + 1/2 (Ld−Lq) × Id ×
Iq] (1) Pn: number of pole pairs ψa: interlinkage magnetic flux Ld: d-axis inductance Lq: q-axis inductance Iq: q-axis current Id: d-axis current Equation (1) shows a voltage equation for dq conversion. There is. For example, in a surface magnet motor, since the magnetic permeability of the permanent magnet is almost equal to that of air, both inductances Ld and L of the above equation (1) are
q becomes almost the same value, and the reluctance torque component shown in the second term in [] of the equation (1) does not occur.

In order to increase the torque of the electric motor driven by using the reluctance torque in addition to the magnet torque, the difference of (Ld-Lq) should be increased according to the equation (1). Since the inductance L, which is the ease with which the magnetic flux can pass, is proportional to N2 (the number of turns of the tooth), if the number of turns of the tooth is increased, the difference of (Ld-Lq) also increases and the reluctance torque can be increased. . However, if the number of turns is increased in order to increase the use of the reluctance torque, the winding group protruding to the end face of the stator, that is, the coil end, increases as the number of turns increases. Therefore, if the reluctance torque is used to efficiently rotate the motor, the coil end becomes large and the motor itself becomes huge.

Further, in distributed winding, a winding ring is formed by winding a winding a plurality of times, and this winding ring is inserted into a tooth, so that the circumference of the winding ring becomes larger than the teeth circumference. Further, in distributed winding, the teeth are wound through the slots, so that the windings cross each other. As described above, in the case of distributed winding, the winding protrudes at the end surface of the stator, and the winding intersects with each other, so that the coil end becomes large. On the contrary, when trying to make the electric motor small, the output of the electric motor is reduced.

Therefore, if the reluctance torque is used to efficiently drive the electric motor, the size of the electric motor becomes large. On the contrary, when trying to make the electric motor small, the output of the electric motor is reduced.

[0007]

However, there is a need for a high-output and downsized electric motor in air conditioners, refrigerators, electric vehicles and the like.

Further, the magnetic poles at the tips of the teeth of the stator are formed wide in the circumferential direction. However, in order to form an opening for winding the slot portion between the adjacent magnetic pole portions, it is necessary to widen the width between the tooth tips in the circumferential direction. In other words, the distributed winding requires an opening for inserting the winding wheel into the tooth. It should be noted that the air gap between the inner circumference of the stator and the outer circumference of the rotor is generally set uniformly over the entire circumference except for the openings of the slots.

In the above-described conventional structure, since the opening portion of the slot portion is interposed between the magnetic pole portions on the stator side, the magnetic flux distribution from the magnetic pole portions has a circumferentially interrupted portion, which causes cogging during rotor rotation. There was a problem that torque was generated. On the rotor side, the cogging torque can be reduced by making the distribution of the magnetic flux from the outer periphery of the rotor closer to a sinusoidal waveform. However, since the gap between the stator inner periphery and the rotor outer periphery is constant, this gap The magnetic resistance is constant over the entire circumference, and the magnetic flux distribution changes abruptly at the portions where the ends of the permanent magnet are adjacent to each other, resulting in a large cogging torque. Thus, there is a problem that a large cogging torque is generated due to the overlapping factors of the cogging torque on both the stator side and the rotor side.

[0010]

The electric motor of the first invention according to the present application has a stator and a rotor,
There is a single winding on the teeth of the
In addition to the magnet torque, the rotor has a reluctant strut.
In an electric motor that is driven to rotate using a
The data consists of multiple core elements and frame parts.
Each of the core elements
Combined in an annular shape at the outer periphery of the frame part
Fixed to the inner circumference, the rotor has a plurality of permanent magnets inside.
The outer circumference of this rotor is adjacent to the end of the permanent magnet section.
A recess is provided in the mating portion, and the recess is a straight cutout.
The position of the bottom of the recess is larger than that of the permanent magnet.
The outer peripheral side of the rotor and the electric power of the second invention according to the present application.
The motivation is that the gap between the rotor outer recess and the tooth outer circumference
Is 0.7 mm or more, and the third of the present application
The electric motor of the invention is driven to rotate at 300 amperes or more.
The fourth invention according to the present application is any of the above.
This is a compressor that uses an electric motor, and
A fifth aspect of the present invention uses any one of the above electric motors.
Electric vehicle, and the sixth invention of the present application
Is an air conditioner using any of the above electric motors ,
The seventh invention related to the present application is
It is a refrigerator using an electric motor, and thus includes a stator core having a plurality of teeth portions, a winding portion having a single winding around the teeth portions, and a rotor having a plurality of permanent magnet portions provided therein. The outer circumference of the rotor is a motor that is driven to rotate using magnet torque and reluctance torque, characterized in that a recess is provided in a portion where the ends of the permanent magnets are adjacent to each other. The space between them becomes large in the area where the permanent magnets are adjacent to each other. In other words, by increasing the magnetic resistance in the void,
The magnetic flux distribution between the inner circumference of the stator and the outer circumference of the rotor approaches a sine wave, and the cogging torque is reduced.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a stator core having a plurality of tooth portions, a winding portion having a single winding around the tooth portion, and a rotor having a plurality of permanent magnet portions provided therein. Is an electric motor that is rotationally driven by using magnet torque and reluctance torque, characterized in that a recess is provided in a portion where the ends of the permanent magnets are adjacent to each other. The gap between the two becomes large in the area where the permanent magnets are adjacent to each other. That is, since the magnetic resistance in the gap increases, the magnetic flux distribution between the inner circumference of the stator and the outer circumference of the rotor approaches a sine wave, and the cogging torque is reduced.

It is preferable that the gap between the inner circumference of the stator core and the outer circumference of the rotor be widened at the portions where the ends of the permanent magnet portions are adjacent to each other. The distance between the rotor outer peripheral recess and the outer periphery of the teeth is 0.7.
It is good that it is mm or more. In addition, it is effective when rotating and driving at 300 amperes or more.

[0013]

Example 1 Example 1 will be described with reference to FIGS. 1 to 4. In FIG. 1, 1 is a magnet torque,
It is a synchronous motor that is driven to rotate using reluctance torque, and is composed of a stator 2, a rotor 3, and a rotating shaft 4. The stator 2 is formed between a ring-shaped frame portion 21, a stator core 22 formed by annularly combining a plurality of independent core elements 5 made of a high magnetic permeability material, and the tooth portions 7, 7 of each core element 5. It is composed of windings wound around the slot portion 8, and a rotating magnetic field is generated by applying a current to these winding groups.

The stator core 22 is constructed by annularly combining a plurality of core elements 5 at their outer peripheral portions 6 and fittingly fixing them to the inner periphery of the frame portion 21. Each outer peripheral portion 6 has its both side surfaces 6a. The extension line is formed into a fan-shaped overall shape that passes through the center of the stator. As shown in detail in FIG. 2, the core element 5 is provided with a slot forming concave portion 9 in its inner peripheral portion, and the slot forming portion 9 is formed between the adjacent tooth portions 7, 7. Has been formed. Further, the both side surfaces 6a are provided with a locking portion 11 including an engagement projection 10a and an engagement recess 10b which engage with each other when the core elements 5 are combined in an annular shape, and the core elements 5 are firmly fixed to each other. It is configured to be. The core element 5 is combined by welding, but a fitting portion may be provided on the side surface of the core element 5 and the core element 5 may be fixed by caulking.

As described above, the stator 2 is formed by combining a plurality of core elements 5. Therefore, the stator 2
After winding the winding around the core element 5 instead of winding the winding around the stator 2, the stator 2 can be molded. In this way, if the winding is performed in the state of the core element 5, since the winding is wound for each core element 5, it is possible to easily perform a single body winding (concentrated winding). This is because, as shown in FIG. 4, when the winding wire 23 is wound, there is no portion on the side surface of the tooth portion 7 that hinders winding. Therefore, the winding opening of the winding device rotates around the tooth portion 7 and can be wound in a line through the insulating film 24. Furthermore, the winding accuracy of the winding 40 can be increased, and the aligned winding can be easily performed.

As described above, by winding the winding of the stator 2 as a single body, it is possible to suppress the intersection of the windings on the end face of the stator. Therefore, since the winding does not intersect at the end face of the stator 5 in the rotation axis direction, the size of the coil end can be suppressed. Furthermore, since the winding is performed in the state where the stator is divided, the length of the circumference of the tooth 5 and the length of one circumference of the winding can be made the same. Therefore, the winding does not project at the end face of the stator, and the coil end can be reduced.

Further, since the stator 5 is wound in a divided state, it is not necessary to consider the space of the winding opening of the winding device during winding, so that the windings can be overlapped as much as possible. In addition, since the stator 5 is wound in a divided state, the accuracy of the winding device is increased and the winding can be performed in an aligned manner. Therefore, the space factor of the slot portion can be increased. Since the reluctance torque is proportional to the number of windings,
Reluctance torque can be increased by increasing the space factor.

As described above, since the winding around the tooth portion can be wound with an appropriate length, there is no extra winding, and the winding length is shortened with respect to the total number of windings. be able to. Therefore, it is possible to reduce copper loss and heat generation of the winding.

Further, since the space d between the tips of the teeth does not require a space for the winding to pass through the winding port of the apparatus, the space d between the tips of the teeth can be reduced. Therefore, the change in the gap between the tooth portion and the outer peripheral portion of the rotor is reduced, and the cogging torque is reduced.

Conventionally, when winding a single winding around the stator 2 with a winding device, the space factor could be only about 30%. However, when the core element 5 is wound and then assembled, the space factor of the slot portion 8 is easily set to 3
It can be 0% or more, and the space factor can be 60% or more.

Further, the magnetic pole portions 12 at the ends on the inner peripheral side of the slot forming recesses 9 of the respective core elements 5 are longly projected to both sides in the circumferential direction, and adjacent core elements are provided with a slight gap d therebetween. 5 is configured so as to be connected to the magnetic pole portion 12 of each core element 5 so that a discontinuous portion does not occur in the magnetic flux distribution in the circumferential direction emitted from the magnetic pole portion 12 of each core element 5. Further, both side portions 12a of the magnetic pole portion 12 are formed in a substantially triangular shape so that the width in the radial direction becomes smaller toward the tip, and adjacent magnetic cores are provided with a large magnetic resistance. Magnetic pole parts 12, 12 of the elements 5, 5
The magnetic leakage between the two is reduced.

The slight gap d in the first embodiment is 0 <d <0.2.
mm. The slight gap d can be obtained by winding the core element 5 and then assembling it. By opening such a small gap, magnetic leakage from the winding of the slot portion 8 can be suppressed, and the cogging torque can be reduced. Becomes smaller. The fact that the gap d is 0 <d <0.2 mm is a value obtained by an experiment, which is a value at which the cogging torque is efficiently reduced. The reason why the tips are not completely contacted is to prevent the ineffective magnetic flux from flowing between the adjacent tooth portions 7.

However, the magnetic flux leakage between the adjacent core elements 5 and 5 can be neglected in this gap d, and it can be set to 0 if there is no problem in the assembling accuracy to eliminate the cogging torque.

Further, b <0.6 mm is suitable for the facing surface (the end surface of the teeth portion 7 and the surface facing each other between the ends of the teeth portion 7) b of the teeth portion 7 at the tips of the teeth portions.
By setting b to b <0.6 mm, magnetic saturation occurs at the tips of the teeth portions 7 and ineffective leakage magnetic flux can be reduced.

On the other hand, the rotor 3 has a rotor core 13 made of a highly permeable material through which the magnetic flux of the rotating magnetic field generated by the winding group of the stator 2 easily passes, and the rotor core 13 is arranged at equal intervals in the circumferential direction corresponding to the poles of the rotor 3. And a permanent magnet 14 provided therein. These permanent magnets 14 are arranged so that S poles and N poles alternate in the circumferential direction.

The teeth facing surface 14a of the permanent magnet 14 is linear. The distance between the teeth facing surface 14 a and the outer circumference of the rotor 13 is wider in the central portion than in the end portions of the permanent magnet 14. As described above, the outer peripheral portion of the rotor 13 is provided with the portion through which the magnetic flux easily passes and the portion through which the magnetic flux does not easily pass, so that an inductance difference between the q-axis inductance and the d-axis inductance can be created, and the reluctance torque is used to drive the rotation. can do. In addition, the shape of the permanent magnet 14 may be a shape in which the central portion projects toward the center of the rotor 13.

The outer periphery of the rotor core 13 has a third
As shown in detail in the figure, a linear cutout portion 15 is formed in a portion where the end portions of the permanent magnet 14 are adjacent to each other.

The outer periphery of the stator 2 is covered with a ring-shaped frame portion 21 to reinforce the integrated core element 5 by welding. In this way, the frame portion 21
By using, the core element 5 is firmly fixed even with a high-speed rotating electric motor. If the assembled stator body of the core elements 5 has sufficient strength, it is not necessary to reinforce by the frame portion 21.

With the above structure, the electric motor of the present invention can be driven by utilizing reluctance torque in addition to magnet torque. Although the space factor of the slot portion 8 of this electric motor is 60% or more, the size of the stator is small.

Therefore, since the output torque of the electric motor which is rotationally driven by utilizing the reluctance torque in addition to the magnet torque has a relationship as shown in the equation (1), when the space factor of the slot portion 8 is increased, Ld The difference between −Lq becomes large, and the output torque can be increased. Because the inductance L is in proportion to N2 (number of turns), the higher the number of turns, that is, the higher the space factor in the slot portion 8, the higher the output.

Therefore, in a motor driven by utilizing reluctance torque in addition to magnet torque, when winding is wound around the core element 5 and then combined with the stator 2, the space factor can be increased, resulting in high output and Can be small.

The width of the adjacent permanent magnets is the width of the teeth (8 in FIG. 1) facing the two poles (two permanent magnets).
In a pole 12 slot, there are three teeth that face two poles. With 8 poles and 4 slots, the number of teeth is 6, and it is found that the torque ripple is reduced by 0.15 to 0.20.

In the rotor 3, the rotor core 1
A substantially linear cutout portion 15 serving as a rotor outer peripheral concave portion is formed at a portion of the outer peripheral portion of the permanent magnet 14 where the end portions of the permanent magnet 14 are adjacent to each other. As described above, when the cutout portion 15 is provided, the gap between the inner circumference of the stator 2 and the outer circumference of the rotor 3 becomes smaller than that of the permanent magnet 1.
The ends of 4 become larger at the adjacent parts. Therefore, since the magnetic resistance in the gap is large, the magnetic flux distribution in the gap between the inner circumference of the stator 2 and the outer circumference of the rotor 3 can be approximated to a sinusoidal waveform.

It is to be noted that the length of the rotor outer peripheral recessed portion located outside the portion between the adjacent permanent magnets is appropriately a length corresponding to an angle of 0.2 to 0.4 of the central angle of one pole of the rotor core. is there.

The gap h between the tooth portion 7 and the cutout portion 15 must be at least twice the gap between the tooth portion 7 and the rotor outer periphery. In addition, in the case of Example 1, it was found from an experiment that it is appropriate that the gap between the tooth portion 7 and the excised portion is 0.7 to 1 mm.

As described above, in the first embodiment, since the cogging torque generation factors on both the stator 2 side and the rotor 3 side can be suppressed, it is possible to provide a synchronous motor with a small cogging torque.

By using such an electric motor in a compressor, a refrigerator, an air conditioner, an electric vehicle, etc., it is possible to achieve the effects of downsizing and widening the storage space.

The electric motor used in the electric vehicle needs to be downsized in order to increase the space in the company, and the electric current that can efficiently use the current of the charger is required. Also, the electric motor used for electric bicycles is a rectangular wire,
In many cases, a cross section having a width of 4 mm or more and a height of 1.5 mm or more is used. In addition, the large current flowing through the winding is often 300 amperes or more. Then, a large current is made to flow and 7000 to 150
Since the motor rotates 00 times, it is effective to use an electric motor having a short winding length and a small amount of heat generation with respect to the number of windings, like the electric motor of the present invention. Further, if the winding can be performed in line, the space factor can be further increased as compared with the round wire.

It is very effective to use the electric motor according to the present invention for an electric motor such as an electric vehicle that passes a large current.

In the above description, an electric motor using a single-body stator in which a permanent magnet is embedded and a reluctance torque is used in addition to the magnet torque has been described. However, instead of the permanent magnet, a gap made of a low-permeability material is used. Alternatively, an excellent effect can be obtained even if a resin material is provided inside the rotor and rotationally driven using only reluctance torque. That is, even if a single-rolled stator is used for the synchronous motor, excellent effects can be obtained. Example 2 Example 2 will be described with reference to FIG.

In FIG. 5, reference numeral 31 denotes a synchronous motor that mainly rotates in the forward rotation direction F by utilizing reluctance torque in addition to magnet torque, and is composed of a stator 32, a rotor 33 and a rotary shaft 34. There is.

The stator 32 includes a ring-shaped frame portion and a plurality of independent core elements 3 made of a high magnetic permeability material.
It is composed of a stator core formed by combining 5 in an annular shape and windings wound around a slot portion 38 formed between the teeth portions 37, 37 of each core element 35, and a current is applied to these winding groups. As a result, a rotating magnetic field is generated.

Then, a permanent magnet 39 is embedded in the rotor 33 provided in the stator 32. The shape of the permanent magnet 39 is V-shape, and the permanent magnet is the rotor 3
It projects toward the center of 3. In this way, the reverse saliency makes it possible to make the inductance difference between the d-axis and the q-axis large. In addition, this permanent magnet 39
Is a front portion 39a of the permanent magnet 39a in the forward rotation direction F of the rotor.
b and a permanent magnet rear portion 39b. At this time, the thickness of the permanent magnet rear portion 39b is larger than the thickness of the permanent magnet front portion 39a.

The reason for having such a configuration is as follows. In the permanent magnet rear portion 39b, the permanent magnet rear portion 39b
And the magnetic flux output from the tooth portion 37 repel each other, which may cause demagnetization of the permanent magnet rear portion 39b. Therefore, a permanent magnet that generates a magnetic force that does not cause demagnetization is required, and thus the permanent magnet is made thick.

However, in an electric motor in which most rotations rotate only in the forward rotation direction F, the permanent magnet front portion 39a attracted by the attraction force from the teeth is
Since demagnetization does not occur, it is not necessary to have the same thickness as the permanent magnet rear portion 39b. Therefore, the permanent magnet rear portion 39b
The permanent magnet front portion 39a may be made thinner. Therefore,
Even if the amount of permanent magnets is reduced in an electric motor that performs most rotations in positive rotation, the amount of permanent magnets can be reduced without lowering the characteristics.

The rear portion 39b of the permanent magnet provided inside is
The tooth-opposing surface of is protruding toward the stator 35 and is thicker than the permanent magnet front portion 39a. However, the teeth-opposing surface of the rear portion 39b of the permanent magnets provided inside the front portion 39 of the permanent magnets is
It may be symmetrical with the facing surface of a and may project toward the center of the rotor.

When the magnet is embedded in the rotor, a weight for adjusting the balance between the front portion and the rear portion may be embedded in the rotor when the magnet is rotationally driven.

Further, the shape of the permanent magnet is not limited to the V shape, but may be a linear shape or an arc shape. Example 3 Example 3 will be described with reference to FIG.

In FIG. 6, reference numeral 51 denotes a synchronous motor that rotates by utilizing reluctance torque in addition to magnet torque, and is composed of a stator 52, a rotor 53, and a rotary shaft 54.

The stator 52 is formed by combining a plurality of independent core elements 55 made of a high magnetic permeability material in an annular shape. Each core element 55 is composed of a winding wound around a slot 58 formed between the teeth 57, 57, and a rotating magnetic field is generated by applying a current to the winding group. Has been done.

The rotor 53 is fixed to a rotor core made of a high magnetic permeability material by fixing four sets of permanent magnets 59 and 60 arranged so that N poles and S poles alternate with each other to the embedded rotor shaft 54. ing. The permanent magnet per pole is divided into two in the radial direction of the rotor and is composed of an outer permanent magnet 59 and an inner permanent magnet 60. Each of the permanent magnets 59, 60 is formed in an arc shape that is convex toward the center of the rotor, and both ends 59a, 60a extend to positions close to the outer circumference of the rotor. The distance between the outer peripheral permanent magnet 59 and the inner peripheral permanent magnet 60 has a substantially constant width, and a passage 61 through which the magnetic flux in the q-axis direction passes is formed in this distance.

The stator 52 has a predetermined number of teeth 57.
Each tis 57 is provided with a winding wire (not shown). Since the winding at this time is wound for each core element 55, it can be wound as a single body. A rotating magnetic flux is generated by applying an alternating current to the stator winding, and the rotating magnetic flux causes a magnet torque and a reluctance torque to act on the rotor 53, thereby rotating the rotor 53.

The width M between the outer peripheral permanent magnet 59 and the inner peripheral permanent magnet 60 is desired to be as small as possible considering the magnetomotive force loss of the permanent magnets 59, 60. However, q
From the viewpoint of the axial inductance Lq, in order to increase the axial inductance Lq, it is desired that the axial inductance Lq is large enough not to cause magnetic saturation.

Therefore, in the third embodiment, since the width is such that the magnetic flux generated by the current flowing through the winding is not saturated, the width M
Is set to 1/2 of the width N of the tooth 56.
When the width M and the q-axis inductance Lq are investigated, it becomes smaller than the width N1 / 3 of the tooth 57 having the width M. On the other hand, even if the width M becomes larger than the width N of the tooth 57, the q-axis inductance Lq hardly changes. Therefore, from this investigation, the distance between the outer peripheral side permanent magnet 59 and the inner peripheral side permanent magnet 60, that is, the width M may be set to be larger than 1/3 of the width N of the stator 57.

In the third embodiment, the magnetic flux path is formed by a plurality of layers of permanent magnets, but any number of layers may be used as long as it is a plurality of layers, but it is experimentally found that the efficiency is best when the number of layers is two. all right.

(Example 4) A fourth embodiment will be described with reference to FIGS. 7 and 8.

In FIG. 7, reference numeral 71 denotes a synchronous electric motor which rotates by utilizing reluctance torque in addition to magnet torque, and is composed of a stator 72 and a rotor 73.

The stator 72 has a ring-shaped frame portion 7
4, a stator core formed by annularly combining a plurality of independent core elements 75 made of a high magnetic permeability material, and a winding wound around a slot 78 formed between the teeth 77, 77 of each core element 75. 80, and is configured to generate a rotating magnetic field by applying a current to these winding groups.

As shown in FIG. 8, the core elements 75 are connected to the ends of the core elements 75 to form a core element group. The core element group is provided with a space portion in the bent portion 81 at the end portion so that it can be easily bent. By thus winding the winding 80 with the core element group and bending the winding to form the stator 72, positioning of the assembly of the stator becomes easy. At this time, each core element 75 may be welded and connected, or the ring-shaped frame portion 74 may be fitted and fixed.

It should be noted that one core element group may form an annular stator, or a plurality of core element groups may be combined to form an annular stator.

Further, the stator may be formed by solidifying the core element group with resin or the like instead of contacting the end faces of the core element 75 to form the stator.

[0062]

The electric motor of the present invention can reduce the cogging torque.

[Brief description of drawings]

FIG. 1 is a sectional view of an electric motor according to a first embodiment.

FIG. 2 is a partial sectional view of the stator.

FIG. 3 is a partial sectional view of the rotor.

FIG. 4 is a view showing the core element.

FIG. 5 is a sectional view of an electric motor according to the second embodiment.

FIG. 6 is a sectional view of an electric motor according to the third embodiment.

FIG. 7 is a sectional view of an electric motor according to the fourth embodiment.

FIG. 8 is a partial cross-sectional view of a core element group of the electric motor according to the fourth embodiment.

[Explanation of symbols]

1 electric motor 2 stator 3 rotor 14 permanent magnet 15 excision part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H02K 21/16 H02K 21/16 M (72) Inventor Yukio Honda 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. ( 72) Inventor Hiroshi Murakami 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Shinichiro Kawano 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References Japanese Patent Laid-Open No. 8-336246 (JP, A) Japanese Patent Laid-Open No. 7-336980 (JP, A) Japanese Patent Laid-Open No. 7-255138 (JP, A) Japanese Patent Laid-Open No. 7-236240 (JP, A) Japanese Patent Laid-Open No. 7-46809 (JP , A) JP 7-33698 (JP, A) JP 5-304737 (JP, A) JP 5-236688 (JP, A) JP 4-299002 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02K 1/27 5 01 H02K 1/18 H02K 1/22 H02K 19/10 H02K 21/16

Claims (7)

(57) [Claims] 1. A stay comprising a stator and a rotor,
There is a single winding on the teeth of the
In addition to the magnet torque, the rotor has a reluctant strut.
In an electric motor that is driven to rotate using a
The data consists of multiple core elements and frame parts.
Each of the core elements
Combined in an annular shape at the outer periphery of the frame part
Is fixed to the inner peripheral, the rotor has a plurality of permanent magnets is internally provided, the outer periphery of the rotor recess is provided in a portion adjacent the end portion of the permanent magnet portion, the recess linear cutouts
The position of the bottom of the recess is larger than that of the permanent magnet.
An electric motor on the outer circumference side of the rotor . 2. The electric motor according to claim 1, wherein a gap between the rotor outer peripheral recess and the outer periphery of the tooth is 0.7 mm or more. 3. The electric motor according to claim 1, which is rotationally driven at 300 amperes or more. 4. A compressor using the electric motor according to claim 1. 5. An electric vehicle using the electric motor according to claim 1. 6. An air conditioner using the electric motor according to claim 1. 7. A refrigerator using the electric motor according to claim 1.