KR20180069955A - Rotor having a skewed rotor core and motor of flux concentrate type comprising the same - Google Patents

Abstract

The present invention relates to a rotor having a skewed rotor iron core and a motor of flux concentrate type including the same, to insert an integral type permanent magnet which is not divided and apply a skew to a rotor iron core to make air magnetic flux density sinusoidal and to lower a cogging torque and an induced voltage distortion. The rotor iron core according to the present invention is formed by stacking rotor iron plates which have permanent magnet insertion holes opened to on the outer circumferential surface. Each of the rotor iron plates has first and second edge parts for restricting the permanent magnets inserted into the permanent magnet insertion holes on both sides of the opened part of the permanent magnet insertion hole. The first and second edge parts are skewed in different axial lengths. Manufacturing processes can be simplified.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rotor having a skewed rotor core, and a magnetic flux concentrating motor including the skewed rotor core,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic flux concentrating type motor, and more particularly, to a magnetic flux concentrating type motor having a magnetic flux density which is made sinusoidal by applying a skew to a rotor iron core to reduce cogging torque and THD (Total Harmonic Distortion) To a concentrated type rotor and a magnetic flux concentrating type electric motor including the same.

Recently, interest in and demand for electric vehicles is increasing as the exhaustion of fossil fuels and the environmental problems caused by the use of fossil fuels are highlighted. An important technical factor for the commercialization of electric vehicles is a battery supplying electric energy and an electric motor converting electric energy supplied from the battery into mechanical energy for driving.

In order to use electric motors in electric vehicles, high efficiency and high output are required. At this time, a permanent magnet type motor is used as an electric motor as well as an induction motor.

Among the permanent magnet type electric motors, there is an embedded permanent magnet motor in which permanent magnets are embedded (embedded) in the rotor. In the buried permanent magnet motor, the magnetic flux concentrating type motor has a structure in which permanent magnets are radially inserted into the rotor iron core around the rotation axis.

In order to improve the operating characteristics of such a magnetic flux concentrating motor, various structures for making the vacant magnetic flux density to be sinusoidal have been studied and introduced.

There is a method of applying a skew to the rotor as a method for making the vacancy magnetic flux density sinusoidal. To apply the skew to the rotor, the angle of the rotor iron core including the permanent magnet should be changed in the direction of lamination of the rotor iron plate. For example, in order to manufacture a rotor to which step skew is applied in three stages, a first permanent magnet is inserted after stacking a single-stage rotor iron core, a two-stage rotor iron core is laminated on a first rotor iron core, And a third permanent magnet is inserted after the three-stage rotor iron core is laminated on the two-stage rotor iron core. Thus, the rotor to which the three-stage step skew is applied can be manufactured. In this case, the rotor having the three-step step skew has a structure in which the second-stage and third-stage rotor iron cores are rotated at a predetermined angle with respect to the first-stage rotating iron core. Accordingly, the first to third permanent magnets inserted in the first- to third-stage rotor iron core are positioned to be shifted from each other in the axial direction corresponding to a certain angle of rotation.

In such a conventional step skew method, since the process of stacking the rotor iron cores and inserting the permanent magnets corresponding to the number of steps applied to the rotor must be repeatedly performed, the manufacturing process is complicated and the manufacturing time is long, Has a falling problem. Therefore, the existing step skewing method is a factor for raising the manufacturing cost of the magnetic flux concentration type electric motor.

Also, since the rotor iron core needs to be stacked while rotating at a certain angle in the axial direction of the rotor, manufacturing errors may occur depending on the rotation angle in the manufacturing process.

Korean Registered Patent No. 10-0263533 (registered on May 17, 2000)

Accordingly, an object of the present invention is to provide a rotor having a rotor iron core to which a skew is applied, which can simplify a manufacturing process while applying a skew to a rotor core, and a magnetic flux concentrating motor including the rotor.

Another object of the present invention is to provide a rotor having a rotor iron core to which a skew is applied, which can suppress a problem of manufacturing error according to a rotation angle in the process of manufacturing a rotor having a skewed rotor core, And to provide a concentrated type electric motor.

In order to achieve the above object, according to the present invention, a rotary shaft insertion hole into which a rotary shaft is inserted is formed at the center, permanent magnet insertion holes into which a plurality of permanent magnets are respectively inserted are formed around the rotary shaft insertion hole, And a plurality of rotor iron plates formed in an open form and stacked in the axial direction of the rotor shaft insertion holes. At this time, the plurality of rotor iron plates are formed such that first and second edge portions for restricting the permanent magnets inserted into the permanent magnet insertion holes are formed on both sides of the opened portion of the permanent magnet insertion hole, respectively. The first and second edge portions of the plurality of rotor iron plates are different in the axial length from each other to apply a skew to the iron core.

The permanent magnet insertion holes are formed at the same position in the axial direction so that one permanent magnet can be inserted into each of the permanent magnet insertion holes.

Each of the plurality of rotor iron plates may have the same distance between the first edge portion and the second edge portion.

The plurality of rotor iron plates may increase or decrease the length of the first and second edge portions in the axial direction.

The length of the second edge portion may linearly decrease when the length of the first edge portion linearly increases in the axial direction of the plurality of rotor iron plates. Or if the length of the first edge portion decreases linearly, the length of the second edge portion may increase linearly.

The length of the second edge portion may be gradually decreased when the length of the first edge portion increases stepwise in the axial direction of the plurality of rotor iron plates. Or if the length of the first edge portion decreases stepwise, the length of the second edge portion may increase stepwise.

The present invention also relates to a magnetic bearing device comprising: a rotating shaft; The rotor iron core to which skew is applied; And a plurality of permanent magnets inserted into the plurality of permanent magnet insertion holes of the rotor iron core, respectively, and a rotor iron core having skew applied thereto.

The present invention also provides a rotor having the rotor iron core to which a skew is inserted into which a rotary shaft is inserted, And a stator having a rotor insertion hole in which a rotor is inserted and installed at a central portion thereof and having a coil wound around an inner circumferential surface of the rotor insertion hole, Thereby providing a concentrated type electric motor.

According to the present invention, the permanent magnet insertion hole is formed in the rotor iron core as a straight line, and the first and second edge portions, which confine the permanent magnets inserted into the permanent magnet insertion hole, The integral permanent magnet which is not divided into the permanent magnet insertion holes formed in a single row can be inserted all at once, so that the manufacturing process can be simplified while applying skew to the rotor iron core. That is, in the case of a conventional rotor iron core with a skew, the manufacturing process is complicated because the permanent magnets must be divided into portions corresponding to the number of stages to be stacked and inserted into the rotor iron core of each stage. However, according to the present invention, since the permanent magnet which is not divided can be inserted at once, the manufacturing process of the rotor can be simplified.

In the manufacturing process of the rotor having the rotor iron core with the conventional skew, manufacturing error may occur depending on the rotation angle. However, according to the present invention, after the rotor iron core is stacked, Therefore, it is possible to suppress the problem of manufacturing error due to the existing rotation angle.

By applying skew to the rotor, the air gap magnetic flux density can be made sinusoidal to lower the cogging torque and the counter electromotive force external shape factor.

1 is a plan view showing a magnetic flux concentrating type electric motor according to a first embodiment of the present invention.
FIG. 2 is an exploded perspective view showing a rotor having a rotor iron core to which the skew of FIG. 1 is applied.
Figure 3 is a perspective view showing the rotor of Figure 2;
FIG. 4 is a plan view showing the rotor of FIG. 3;
Figure 5 is a side view of the rotor of Figure 3;
6 is a side view showing the rotor of the magnetic flux concentrated type electric motor according to Comparative Example 1. [Fig.
7 is a side view showing a rotor of a magnetic flux concentrating type electric motor according to a second comparative example.
8 is a graph showing the back electromotive force external shape factor of the magnetic flux concentrated type electric motor according to the first embodiment and the comparative example.
9 is a graph showing the cogging torque generated in the magnetic flux concentrated type electric motor according to the first embodiment and the comparative example.
10 is a side view showing a rotor of a magnetic flux concentrating type electric motor according to a second embodiment of the present invention.
11 is a side view showing a rotor of a magnetic flux concentrating type electric motor according to a third embodiment of the present invention.
12 is a side view showing a rotor of a magnetic flux concentrating type electric motor according to a fourth embodiment of the present invention.

In the following description, only parts necessary for understanding embodiments of the present invention will be described, and descriptions of other parts will be omitted to the extent that they do not disturb the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention, so that various equivalents And variations are possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

1 is a plan view showing a magnetic flux concentrating type electric motor according to a first embodiment of the present invention.

Referring to FIG. 1, a magnetic flux concentrated type electric motor 100 according to the first embodiment includes a rotor 20 and a stator 10 into which the rotor 20 is rotatably inserted. The stator 10 has a rotor insertion hole 18 formed at the central portion thereof and a coil 16 wound around the inner circumferential surface of the rotor insertion hole 18. [ The rotor 20 is inserted into the rotor insertion hole 18 of the stator 10 and is rotatably installed.

The stator 10 includes a stator core 11 formed with a rotor insertion hole 18 and a coil 16 wound along the inner circumferential surface of the rotor insertion hole 18 of the stator core 11. [ At this time, the inner diameter of the rotor insertion hole 18 is formed larger than the outer diameter of the rotor 20, and the difference between the inner diameter of the rotor insertion hole 18 and the outer diameter of the rotor 20 forms a gap.

The stator iron core 11 can be formed by laminating a plurality of stator iron plates 12 of the same shape in the axial direction. The stator iron core 11 has a rotor insertion hole 18 in which a rotor 20 is inserted and positioned. The stator core (11) has a plurality of teeth (14) formed at regular intervals along the inner circumferential surface. The plurality of teeth 14 protrude from the inner circumferential surface of the stator core 11 toward the central axis of the stator core 11 and are disposed close to the outer circumferential surface of the rotor 20 inserted into the rotor insertion hole 18 do. At this time, a silicon steel plate may be used as the stator steel plate 12. The inside of the imaginary plane formed by the end of the tooth 14 on the inner side of the stator core 11 forms the rotor insertion hole 18.

The coil 16 is wound on each of the plurality of teeth 14 so that a rotating magnetic flux is generated due to the structure of the stator 10 when AC power is applied.

Although not shown, the rotary shaft 30 is rotatably installed in a casing or a shell forming a case of the magnetic flux concentrating type electric motor 100 through bearings.

The rotor 20 is a rotor 20 of a magnetic flux concentrating type electric motor 100 that is inserted into a rotor insertion hole 18 of the stator 10 so as to be rotatably installed and includes a rotating shaft 30, 21 and a plurality of permanent magnets 22 inserted in the rotor core 21. [

The rotary iron core 21 is formed with a rotary shaft insertion hole 25 into which a rotary shaft 30 is inserted. A plurality of permanent magnet insertion holes 25 are formed around the rotary shaft insertion hole 25, (Not shown).

The rotor iron core 21 is formed by laminating a plurality of rotor iron plates 24 in the axial direction. The rotor core 21 has a rotation shaft insertion hole 25 into which a rotation shaft 30 is inserted. The rotor core 21 has a plurality of permanent magnet insertion holes 26 formed in the outer periphery of the rotation shaft insertion hole 25. [

The rotor iron plate 24 may be a silicon steel plate. The rotary shaft insertion hole 25 and the permanent magnet insertion hole 26 may be formed in a direction perpendicular to the upper surface of the rotor core 21. [ That is, one permanent magnet (22) is inserted into each of the plurality of permanent magnet insertion holes (26).

The permanent magnet insertion hole 26 is formed to be open to the outer peripheral surface of the rotor iron core 21. [ At this time, reference numeral 27 denotes an opening of the permanent magnet insertion hole 26.

Each of the plurality of rotor iron plates 24 is provided with first and second permanent magnets 22 for restricting the permanent magnets 22 inserted into the permanent magnet inserting holes 26 on both sides of the openings 27 of the permanent magnet inserting holes 26, And the edge portions 28 and 29 are formed to protrude. The first and second edge portions 28 and 29 of the plurality of rotor iron plates 24 have different lengths protruding in the axial direction and skew is applied to form the rotor iron core 21. [ The skewed rotor iron core 21 will be described later.

The plurality of permanent magnets 22 are inserted into the plurality of permanent magnet insertion holes 26 to form N and S poles, respectively.

The plurality of permanent magnets 22 are inserted into the rotor core 21 in a radial manner about the rotary shaft 30 and can be inserted into the rotor core 21 obliquely with respect to the axial direction of the rotary shaft 30 . Each of the plurality of permanent magnets 22 may have a trapezoidal shape in section. In this case, the cross section refers to a plane perpendicular to the axial direction of the rotary shaft 30. That is, the permanent magnet 22 includes the lower side, the upper side, and both sides connecting the lower side and the upper side. Both sides of the permanent magnet 22 correspond to one side close to the rotary shaft 30 and the other side close to the circumferential surface of the rotor iron core 21. [

Each of the plurality of permanent magnets 22 is positioned parallel to the long side of the adjacent permanent magnet 22 adjacent to the rotary shaft 30, As shown in FIG. The reason for inserting the plurality of permanent magnets 22 into the rotor core 21 in this way is to maximize the cross sectional area occupied by the plurality of permanent magnets 22 in the rotor core 21. [

Since the cross-sectional area occupied by the plurality of permanent magnets 22 in the rotor core 21 can be maximized, the material of the permanent magnets 22 can be replaced with a ferrite material instead of a rare earth element generally used. Of course, a rare earth permanent magnet can be used as the permanent magnet 22.

The permanent magnet 22 can be inserted into the rotor core 21 obliquely at an angle between 0 and 90 degrees with respect to the axial direction of the rotary shaft 30. [ Preferably, the permanent magnet 22 is inserted into the rotor core 21 obliquely at an angle between 60 and 80 degrees.

On the other hand, a plurality of permanent magnets may be formed in a rectangular shape and inserted obliquely with respect to the axial direction of the rotary shaft. However, in this case, there is a limit in increasing the cross sectional area occupied by the plurality of permanent magnets in the rotor iron core. That is, since the interval between the permanent magnets becomes farther from the center of the rotor to the outer periphery of the rotor, the cross sectional area occupied by the plurality of permanent magnets in the rotor iron core is reduced.

On the other hand, when the trapezoidal permanent magnet 22 is used as in the first embodiment, the distance between the permanent magnets 22 from the center of the rotor 20 to the outer periphery of the rotor 20 becomes a little However, the cross-sectional area occupied by the permanent magnets 22 can be widened as compared with the rectangular shape.

As described above, according to the first embodiment, by inserting the trapezoidal permanent magnet 22 obliquely into the rotor iron core 21 in the axial direction of the rotating shaft 30, the permanent magnet 22 inserted into the rotor iron core 21 The thickness and the length of the belt 22 can be increased to improve the torque density.

Therefore, the torque density can be improved by increasing the magnetic flux amount of the rotor 20 in the limited rotor 20 size.

The permanent magnet 22 of the magnetic flux concentrating type rotor 20 according to the first embodiment is disposed such that one side adjacent to the rotation axis 21 is positioned parallel to the lower side of the neighboring permanent magnet 22, It is possible to maximize the thickness and the length of the permanent magnet 22 inserted into the rotor core 21 because the permanent magnet 22 is located close to the circumferential surface of the rotor core 21. [

The rotor 20 having the skew applied rotor iron core 21 according to the first embodiment will now be described with reference to FIGS. 2 to 5. FIG. Here, FIG. 2 is an exploded perspective view showing the rotor 20 having the rotor iron core 21 to which the skew of FIG. 1 is applied. 3 is a perspective view showing the rotor 20 of FIG. 4 is a plan view showing the rotor 20 of Fig. And FIG. 5 is a side view showing the rotor 20 of FIG.

Referring to Figs. 2 to 5, the rotor 20 according to the first embodiment has disclosed an example in which the step skew is applied using the first and second edge portions 28 and 29.

The permanent magnet insertion holes 26 are formed so as to be disposed at the same position in the axial direction so that one permanent magnet 22 that is not divided into the permanent magnet insertion holes 26 can be inserted.

The plurality of rotor iron plates 24 are each formed so that the distance a between the first edge portion 28 and the second edge portion 29 is the same. Of course, the distance b between the first and second edge portions 28, 29 is narrower than the width b of the permanent magnet insertion hole 26.

The plurality of rotor iron plates 24 are formed such that the lengths t1 and t2 of the first and second edge portions 28 and 29 increase or decrease in the axial direction. The lengths t1 and t2 of the first and second edge portions 28 and 29 are the lengths protruding from the inner surface of the permanent magnet insertion hole 26 toward the opening 27.

The plurality of rotor iron plates 24 are formed such that the length t2 of the second edge portion 29 gradually decreases in the axial direction when the length t1 of the first edge portion 28 increases stepwise . Conversely, when the length t1 of the first edge portion 28 is gradually decreased, the length t2 of the second edge portion 29 can be formed to increase stepwise.

For example, the rotor iron core 21 according to the first embodiment has disclosed an example in which a three-step step skew is applied. The rotor iron core 21 according to the first embodiment includes a first unit rotor iron core 21a, a second unit rotor iron core 21b stacked on the first unit rotor iron core 21a, And a third unit rotor core 21c stacked on the electron core 21b.

In this case, the first to third unit rotor iron cores 21a, 21b, and 21c include a plurality of rotor iron plates 24 having the same shape, and the first embodiment includes the same number. However, .

The first edge 28 of the first unit rotor iron core 21a is formed longer than the second edge 29. The length t1 of the first edge portion 29 becomes shorter toward the first unit rotor iron core 21a, the second unit rotor iron core 21b and the third unit rotor iron core 21c. Conversely, the length t2 of the second edge portion 29 becomes longer toward the first unit rotor iron core 21a, the second unit rotor iron core 21b, and the third unit core iron core 21c.

The rotor iron plates 24 of the first to third unit rotor iron cores 21a, 21b and 21c are composed of three different types of rotating angles, but the pole-arcs are the same. Therefore, when the first to third unit rotor iron cores 21a, 21b and 21c are laminated, the permanent magnet insertion holes 26 are positioned in a straight line in the axial direction.

Therefore, the permanent magnet insertion holes 26 formed by the first to third unit rotor iron cores 21a, 21b and 21c are formed in the shape of a straight line. As a result, the integral permanent magnet 22, which is not divided into the rotor iron core 21 according to the first embodiment, can be inserted at a time.

Then, skew is applied to the rotor iron core 21 by increasing or decreasing the lengths t1 and t2 of the first and second edge portions 28 and 29.

As described above, since the rotor core 21 according to the first embodiment is formed with the permanent magnet insertion holes 26 in a straight line while applying the skew, the integral permanent magnet 22 ) Can be inserted at once. Therefore, according to the first embodiment, the manufacturing process of the skew-applied rotor 20 can be simplified compared with the conventional skew method.

In order to examine the characteristics of the magnetic flux concentrated type electric motor 100 including the rotor 20 having the rotor iron core 21 to which the skew was applied according to the first embodiment as described above, Type motor.

As shown in Fig. 6, the rotor concentrating type electric motor according to the comparative example 1 has the rotor 820 in which skew is not applied to the rotor core 21. [ The lengths t1 and t2 of the first and second edge portions 28 and 29 are the same. Since the permanent magnet insertion hole 26 is formed in the shape of a straight line, the integral permanent magnet 22 which is not divided is inserted into the permanent magnet insertion hole 26.

The magnetic flux concentrating type electric motor according to the comparative example 2 has a rotor 920 in which a three-step step skew is applied to the rotor core 21 and the permanent magnet 22 as shown in Fig. That is, the three-stage step skew rotor 920 is constructed such that the first permanent magnet 22a is inserted after the first-stage rotor iron core 21a is laminated, the two-stage rotor iron core 21b is placed on the first- A third permanent magnet 22c was inserted after the second permanent magnet 22b was inserted, the three-stage rotor iron core 21c was laminated on the two-stage rotor iron core 21b, and the third permanent magnet 22c was inserted. At this time, the rotor 920 to which the three-step step skew is applied has a structure in which the second-stage and third-stage rotor iron cores 21b and 21c are rotated at a certain angle with respect to the first-stage rotor iron core 21a.

At this time, the lengths t1 and t2 of the first and second edge portions 28 and 29 are the same. However, since the first- to third-stage rotor iron cores 21a, 21b, and 21c are rotated at a certain angle with respect to each other, the permanent magnet insertion holes 26 can not be formed in a straight line but are formed to be angular in accordance with the rotated angle. Thus, the permanent magnets 22 are divided into three stages, and the permanent magnets 22a, 22b, and 22c divided into three stages are respectively connected to the first rotor iron core 21a, the second rotor iron core 21b, And inserted into the single rotor iron core 21c.

8 is a graph showing the back electromotive force external shape factor of the magnetic flux concentrated type electric motor according to the first embodiment and the comparative example. And FIG. 9 is a graph showing the cogging torque generated in the magnetic flux concentrated type electric motor according to the first embodiment and the comparative example. Here, the graphs shown in Figs. 8 and 9 are analytical results using Finite Element Analysis (FEA). Non_skew indicates the first comparative example, Core_3step_skew indicates the first embodiment, and Conventional_3step_skew indicates the second comparative example.

Table 1 shows the counter electromotive force and the cogging torque of the magnetic flux concentrated type electric motor according to the first embodiment, the first comparative example and the second comparative example.

Comparative Example 1 Comparative Example 2 First Embodiment Up counter electromotive force fundamental wave [Vrms] 32.4 32.1 32.2 Back EMF THD [%] 7.5 5.4 5.3 Cogging torque pk-pk [Nm] 1.35 0.40 0.39

Referring to FIG. 8, it can be seen that the back electromotive force outer ratio is improved in the first embodiment and the second embodiment in which skew is applied, as compared with the first embodiment in which skew is not applied.

Referring to FIG. 9, it can be seen that the cogging torque is reduced in the first embodiment and the second embodiment in which skew is applied, as compared with the first embodiment in which skew is not applied.

It can also be seen that the magnetic flux concentration type electric motor according to the first embodiment improves the counter electromotive force external ratio similar to the magnetic flux concentration type electric motor according to the second comparative example and reduces the cogging torque.

However, since the rotor according to the first embodiment has a manufacturing method of inserting integral permanent magnets that are not divided after lamination of the rotor iron core at once, the manufacturing process can be simplified compared to the rotor of Comparative Example 2 .

In the case of Comparative Example 2, manufacturing errors may occur depending on the rotation angle in the process of manufacturing the rotor having the skewed rotor core. However, according to the first embodiment, after the rotor core is stacked, Since the magnet can be inserted at once, it is possible to suppress the problem of manufacturing error due to the rotation angle as in Comparative Example 2. [

[Second Embodiment]

Meanwhile, the skew applied rotor 20 according to the first embodiment has been described as an example in which the first and second edge portions 28 and 29 are formed in a stepwise increasing or decreasing manner, but the present invention is not limited thereto.

10 is a side view showing a rotor 120 of a magnetic flux concentrating type electric motor according to a second embodiment of the present invention.

10, the rotor 120 according to the second embodiment is configured such that the length t1 of the first edge portion 28 gradually increases and decreases, and the length t2 of the second edge portion 29 ) Gradually decreased and then increased. Of course, the distance a between the first and second edge portions 28, 29 is the same.

[Third and fourth embodiments]

On the other hand, the rotors 20 and 120 according to the first and second embodiments disclose examples in which step skew is applied, but the present invention is not limited thereto. For example, as shown in FIGS. 11 and 12, linear skew can be applied to the rotors 220 and 230 according to the third and fourth embodiments.

Here, the linear skew is obtained by linearly decreasing the length t2 of the second edge portion 29 when the length t1 of the first edge portion 28 linearly increases, The linearly decreasing of the length t1 means that the length t2 of the second edge portion 29 increases linearly. Of course, the distance a between the first and second edge portions 28, 29 is the same.

Linearly increasing or decreasing means that the lengths t1 and t2 of the first and second edge portions 28 and 29 change continuously in accordance with the stacking of the rotor steel plate 24. [

11 is a side view showing a rotor 220 of a magnetic flux concentrating type electric motor according to a third embodiment of the present invention.

11, the rotor 220 according to the third embodiment has a structure in which the length t1 of the first edge portion 28 is linearly decreased and the length t2 of the second edge portion 29 is An example of linearly increasing is disclosed. Of course, the distance a between the first and second edge portions 28, 29 is the same.

12 is a side view showing a rotor 320 of a magnetic flux concentrating type electric motor according to a fourth embodiment of the present invention.

Referring to FIG. 12, the rotor 320 according to the fourth embodiment has a structure in which the length t1 of the first edge portion 28 linearly increases and then decreases, and the length of the second edge portion 29 t2) decreases linearly and then increases. Of course, the distance a between the first and second edge portions 28, 29 is the same.

On the other hand, in Figs. 11 and 12, the end portions of the first and second edge portions 28 and 29 are formed as inclined surfaces so that the end portions of the first and second edge portions 28 and 29 are connected to each other to be formed obliquely However, the present invention is not limited to this. For example, the end portions of the first and second edge portions 28 and 29 may be formed as rectangular ends.

In the first and second embodiments, examples in which step skew is applied to the rotors 20 and 120 are disclosed. In the third and fourth embodiments, linear skew is applied to the rotors 22 and 230, no. For example, a combination of a step skew and a linear skew may be applied to the rotor.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention, and are not intended to limit the scope of the invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

10: Stator
11: stator core
12: stator iron plate
14: Tooth
16: Coil
18: rotor inserting hole
20, 120, 220, 320: rotor
21: rotor iron core
21a: first unit rotor iron core
21b: second unit rotor iron core
21c: third unit rotor iron core
22: permanent magnet
24: rotor iron plate
25: rotation shaft insertion hole
26: permanent magnet insertion hole
27:
28: first edge portion
29: second edge portion
30:
100: magnetic flux concentration type electric motor

Claims (14)

Wherein a permanent magnet insertion hole for inserting a plurality of permanent magnets around the rotation axis insertion hole is formed and opened in an outer peripheral surface of the rotary shaft insertion hole, And a plurality of rotor iron plates stacked in the axial direction of the hole,
The plurality of rotor iron plates each have first and second edge portions protruding from both sides of the open portion of the permanent magnet insertion hole to constrain the permanent magnet inserted into the permanent magnet insertion hole,
Wherein the first and second edge portions of a portion of the plurality of rotor iron plates have different skeletal lengths protruding in the axial direction. The method according to claim 1,
Wherein the permanent magnet insertion holes are disposed at the same position in the axial direction so that one permanent magnet can be inserted into each of the permanent magnet insertion holes. 3. The rotor of claim 2,
Wherein a distance between the first edge portion and the second edge portion is the same. The rotor according to claim 3,
And the lengths of the first and second edge portions are increased or decreased. 5. The rotor according to claim 4,
If the length of the first edge portion linearly increases, the length of the second edge portion decreases linearly,
And the length of the second edge portion linearly increases when the length of the first edge portion decreases linearly. 5. The rotor according to claim 4,
If the length of the first edge portion increases stepwise, the length of the second edge portion decreases stepwise,
And the length of the second edge portion increases stepwise when the length of the first edge portion decreases stepwise. A rotating shaft;
Wherein a permanent magnet insertion hole is formed around the rotation axis insertion hole and a plurality of permanent magnets are inserted around the rotation axis insertion hole, A rotor iron core including a plurality of rotor iron plates laminated in the axial direction of the insertion hole; And
And a plurality of permanent magnets inserted into the plurality of permanent magnet insertion holes of the rotor iron core,
The plurality of rotor iron plates each have first and second edge portions protruding from both sides of the open portion of the permanent magnet insertion hole to constrain the permanent magnet inserted into the permanent magnet insertion hole,
Wherein the first and second edge portions of a portion of the plurality of rotor iron plates have a skeleton of the rotor iron core different in the axial direction protruding length. 8. The method of claim 7,
Wherein the permanent magnet insertion holes are formed at the same position in the axial direction so that one permanent magnet can be inserted into each of the permanent magnet insertion holes. The rotor according to claim 8,
Wherein a distance between the first edge portion and the second edge portion is the same. 10. The rotor according to claim 9,
Wherein a length of the first and second edge portions is increased or decreased. A rotor in which a rotating shaft is inserted in a center portion; And
And a stator having a rotor insertion hole in which a rotor is inserted and formed at a central portion thereof and a coil wound around an inner circumferential surface of the rotor insertion hole,
The rotor
The rotating shaft;
Wherein a permanent magnet insertion hole is formed around the rotation axis insertion hole and a plurality of permanent magnets are inserted around the rotation axis insertion hole, A rotor iron core including a plurality of rotor iron plates laminated in the axial direction of the insertion hole; And
And a plurality of permanent magnets inserted into the plurality of permanent magnet insertion holes of the rotor iron core,
The plurality of rotor iron plates each have first and second edge portions protruding from both sides of the open portion of the permanent magnet insertion hole to constrain the permanent magnet inserted into the permanent magnet insertion hole,
Wherein the first and second edge portions of the plurality of rotor iron plates include a rotor having a rotor iron core to which skew is applied, the rotor iron core having different lengths protruding in the axial direction. 12. The method of claim 11,
Wherein the permanent magnet insertion holes are arranged at the same position in the axial direction so that one permanent magnet can be inserted into each of the permanent magnet insertion holes. Magnetic flux concentration type electric motor. 13. The rotor according to claim 12,
Wherein a distance between the first edge portion and the second edge portion is equal to a distance between the first edge portion and the second edge portion. 14. The rotor as claimed in claim 13,
And a length of the first and second edge portions is increased or decreased. A skew-applied rotor iron core includes a rotor.

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