KR20060019118A - Rotor of motor - Google Patents

Abstract

The present invention relates to a rotor of an electric motor, and more particularly, to a rotor of an electric motor in which a plurality of magnets are radially inserted in a circumferential direction of a core and a magnetic flux barrier is formed to block magnetic flux between the magnets; The rotor is further provided with a guide hole for inducing magnetic flux in the vicinity of the barrier, when inducing leakage magnetic flux can increase the average torque generated by the motor and reduce the torque ripple, according to the shape of the guide hole There is an effect that can easily change the characteristics of the generated torque and the degree of torque ripple, respectively.

Motor, rotor, barrier, torque, torque ripple, guide hole, magnetic flux

Description

Rotor of Motor             

1 is a motor provided with a rotor according to the prior art,

2 is a magnetic flux flow diagram at no load in the electric motor with a rotor according to the prior art,

3 is a graph showing the counter electromotive force according to each phase of the motor with a rotor according to the prior art,

Figure 4 is a graph showing the torque generated in the motor with a rotor according to the prior art,

5 is a motor provided with a rotor according to an embodiment of the present invention,

6 is a magnetic flux flow diagram at no load in the motor with a rotor according to an embodiment of the present invention,

7 is a graph showing the counter electromotive force according to each phase of the motor with a rotor according to an embodiment of the present invention,

8 is a graph showing the torque generated in the motor with a rotor according to an embodiment of the present invention,

Figure 9 is a graph showing the torque of the motor with a rotor according to an embodiment of the present invention and the motor with a rotor according to the prior art,

10 is a motor provided with a rotor according to another embodiment of the present invention,

11 is a magnetic flux flow diagram at no load in the electric motor with a rotor according to another embodiment of the present invention,

12 is a graph showing counter electromotive force according to each phase of a motor provided with a rotor according to another embodiment of the present invention;

13 is a graph showing the torque generated in the motor with a rotor according to another embodiment of the present invention,

14 is a graph illustrating torques of an electric motor including a rotor according to another embodiment of the present invention and an electric motor including the rotor according to the related art.

<Explanation of symbols on main parts of the drawings>

3: stator 4: rotor

31: York 32: Slot

33: Teeth 35: Coil

37: void 42: magnet

43: core 44: barrier

45, 45 ': guide hole

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of an electric motor, and more particularly, to a rotor of an electric motor that can further form a guide hole for inducing some leakage magnetic flux generated in a magnet of the rotor to increase the average torque and reduce the torque ripple.

In general, electric motors apply electromagnetic induction, in which magnetic force is generated at right angles to a magnetic field, and electromagnetic force is generated at right angles to magnetic fields. Electric motors are classified into DC motors and AC motors according to the type of power source. .

Induction motor is a kind of AC motor. It is divided into single phase induction motor and three phase induction motor. Single phase induction motor is widely used in electrical products with relatively small output, and three phase induction motor is widely used in high power electrical products. .

1 is a motor with a rotor according to the prior art, Figure 2 is a magnetic flux flow diagram at no load in the motor with a rotor according to the prior art, Figure 3 is a counter electromotive force according to each phase of the motor with a rotor according to the prior art 4 is a graph showing the torque generated in the electric motor with a rotor according to the prior art.

As shown in FIG. 1, the motor according to the related art is a motor having a general shape in which a 9: 6 concentrated winding embedded ferrite magnet is inserted. The stator 1 generates magnetic force when power is applied, and the stator 1 ) And a rotor (2) which rotates electromagnetically in interaction with each other, and a shaft (21) which is fixed to and rotated at the center of the rotor (2).

The stator 1 is manufactured by stacking plate members, and the stator 1 is opened toward the center along the circumferential direction inside the yoke 11 and spaced apart from each other in a ring-shaped yoke 11 constituting a body. And a plurality of slots 12 radially disposed to accommodate the coil 15 and a plurality of teeth 13 protruding toward the center and maintaining a distance between the slots 12 in the circumferential direction. .

A gap 17 is formed between the stator 1 and the rotor 2 for rotor rotation.

The rotor 2 is the rotor 2 is a core 23 constituting a body, and a plurality of magnets are arranged in the circumferential direction and inserted in the longitudinal direction of the rotor 2 inside the core 23 ( 22 and barriers 24 formed between both ends of the magnet 22 to block magnetic flux.

The barrier 24 is formed at each end of the magnet 22 at each end of the magnet 22, and is formed as a hole having a triangular cross-section, the length of which is larger as it moves away from the center direction of the rotor 2.

The magnet 22 is disposed so that the N pole and the S pole are alternated in the circumferential direction when viewed from the cut surface.

On the other hand, the magnetic flux flow is formed in the core 23 of the rotor 2 and the tooth 13 of the stator 1 by the magnet 22 as shown in FIG. 2 at no load. The magnetic flux generated in the magnet 22 does not all direct toward the tooth 13, and part of the magnetic flux is formed between the barrier 24 and the gap 17 between the magnet 22. Able to know.

Looking at the operation of the present invention configured as described above are as follows.

When power is applied to the compressor, the magnetic force generated by the coil 15 is generated in the stator 1, and the rotor 2 rotates by the magnetic flux generated by the magnet 22. Torque is generated by this.

3 is a graph showing the counter electromotive force waveform of each phase when the motor rotates about 1100 RPM, wherein a thick solid line, a thin solid line, and a broken line each show counter electromotive force by each of the three phases. The counter electromotive force waveform can be seen that a part of the back electromotive force includes a distortion such as a swelling phenomenon depending on the arrangement of the magnet and the shape of the rotor.

Figure 4 shows the torque generated when the ideal current applying the three-phase delta connection in the back EMF waveform as shown in Figure 3, the thin solid line at the bottom represents the torque in each of the three phases, the thick solid line at the top of each case Represents the sum of torques. In each case, the torque ripple due to the distortion of the back EMF waveform is shown.

Here, the average torque and the maximum and minimum torque according to the torque according to FIG. 4 are calculated as shown in Table 1 below.

TABLE 1

talk Conventional electric motor Average torque 1.88 Nm Torque 1.96 Nm Torque 1.64 Nm The difference between the maximum and the minimum 0.32 (17% of average torque)

However, the motor with a rotor according to the prior art, as the magnetic flux generated in the magnet 22 provided in the rotor 2 of the motor does not flow to the tooth 13 of the stator 1, Since the waveform of the counter electromotive force is distorted when the motor is driven, there is a problem that the magnitude of the generated torque is reduced, the torque ripple generating the vibration and noise of the motor.

The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a rotor of an electric motor that can increase the average torque generated by the rotation of the motor or reduce the torque ripple.

In addition, it is an object of the present invention to provide a rotor of an electric motor that can cope with only a simple shape deformation of the rotor of the electric motor when trying to cope with the characteristics of torque and the degree of torque ripple required by a mechanism in which the electric motor is mounted.

In the rotor of the motor according to the present invention for solving the above problems a plurality of magnets are radially inserted in the circumferential direction of the core, the rotor of the motor having a magnetic flux barrier to block the magnetic flux between the magnets; The rotor is further formed with a guide hole for inducing magnetic flux in the vicinity of the barrier.

In addition, the guide hole is located between the magnet and the gap of the rotor, and formed near both magnetic poles of the magnet.

In addition, the guide hole is formed long in the radial direction of the rotor.

In addition, a plurality of the guide holes are formed by the number of magnetic fluxes leaked.

Here, the guide hole is inclined in the direction of the magnetic pole of the magnet, or the guide hole is inclined in the direction opposite to the magnetic pole of the magnet.

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

Figure 5 is a motor with a rotor according to an embodiment of the present invention, Figure 6 is a magnetic flux flow at no load in the motor with a rotor according to an embodiment of the present invention, Figure 7 according to an embodiment of the present invention Figure 8 is a graph showing the counter electromotive force according to each phase of the motor with a rotor, Figure 8 is a graph showing the torque generated in the motor with a rotor according to an embodiment of the present invention, Figure 9 is an embodiment of the present invention It is a graph showing the torque of the motor with a rotor according to the motor with a rotor according to the prior art.

The electric motor according to the present invention is a motor having a shape of a 9: 6 immersion-type ferrite magnet inserted therein, and a magnetic force is generated when power is applied, and the motor rotates by electromagnetically interacting with the stator 3. Rotor 4 and a shaft 41 which is fixed to the center of the rotor 4 and rotates.

The stator 3 is manufactured by stacking plate members, and the stator 3 is open toward the center along the circumferential direction inside the yoke 31 and is spaced apart from each other. And a plurality of slots 32 radially arranged to receive the coil 35 and a plurality of teeth 33 protruding toward the center and maintaining a distance between the slots 32 in the circumferential direction. .

A gap 37 is formed between the stator 3 and the rotor 4 for rotor rotation.

The rotor 4 is the rotor 4 is a core 43 constituting the body, and a plurality of magnets are arranged in the circumferential direction and inserted in the longitudinal direction of the rotor 4 inside the core 43 ( 42 and a barrier 44 formed between the neighboring magnets 42 to block the magnetic flux.

The magnet 22 is disposed so that the N pole and the S pole are alternated in the circumferential direction when viewed from the cut surface.

The barrier 44 is formed at each end of the magnet 42 and is formed between the two magnetic poles of the magnet 42, respectively, and the longer the distance from the center direction of the rotor 2 of the triangular cross-section It is formed alone.

The rotor 4 is provided with a plurality of guide holes 45 formed long in the radial direction of the rotor near both magnetic poles between the magnet 42 and the air gap 37.

The guide hole 45 is inclined toward the magnetic pole center of the magnet.

On the other hand, the magnetic flux flow is formed in the core 43 of the rotor 4 and the teeth 33 of the stator 3 by the magnet 42 as shown in FIG. 6 at no load. Some of the magnetic flux generated in the magnet 42 is in the form of a closed curve circulating about the barrier 42 by using the space between the magnet 42 and the air gap 37 and is directed toward the tooth 33. I can't.

Here, as the guide hole 45 is inclined toward the magnetic pole center of the magnet 42, a part of the magnetic flux to be leaked is guided toward the tooth 33 by the guide hole 45 to leak. Part of the magnetic flux to be induced can be directed to the stator 3 to increase the effective magnetic flux.

Therefore, it is more efficient to guide the magnetic flux generated by the guide hole 45 formed by the number of magnetic flux leaking near the barrier 42 toward the stator 3.

Looking at the operation of the present invention configured as described above are as follows.

When power is applied to the compressor, the magnetic force generated by the coil 35 is generated in the stator 3, and the rotor 4 is rotated by the magnetic flux generated by the magnet 42. Torque is generated by this.

FIG. 7 is a graph showing the counter electromotive force waveform of each phase when the motor is rotated about 1100 RPM. The thick solid line, the thin solid line, and the broken line each show the counter electromotive force of each of the three phases over time. It shows that the sum of the counter electromotive force of each phase, the back electromotive force waveform is significantly reduced and has a gentle value compared to the waveform in the conventional electric motor shown in FIG.

FIG. 8 is a graph showing the time-dependent torque generated when the ideal current to which the three-phase delta connection as shown in FIG. 7 is applied is input. The thin solid line at the bottom represents the torque for each phase and the thick solid line at the top. Represents the sum of torques for each phase. As shown in FIG. 9, it can be seen that the torque ripple is remarkably reduced as the distortion of the back EMF waveform decreases.

Here, when the average torque and the maximum and minimum torque according to the torque according to FIG. 9 are compared and calculated, it is shown in Table 2 below.

TABLE 2

talk Conventional electric motor Example Average torque 1.88 Nm 1.92 Nm Torque 1.96 Nm 2.04 Nm Torque 1.64 Nm 1.58 Nm The difference between the maximum and the minimum 0.32 (17% of average torque) 0.46 (22% of average torque)

As shown in <Table 2>, the average torque value is 1.92 Nm, which is about 2% or more and the maximum torque value is 2.04 Nm, which is increased by about 4% or more, and the difference between the maximum value and the minimum value is 0.46 (22% of the average torque). As a result, the difference increased by about 43%.

Figure 10 is a motor with a rotor according to another embodiment of the present invention, Figure 11 is a magnetic flux flow at no load in the motor with a rotor according to another embodiment of the present invention, Figure 12 according to another embodiment of the present invention FIG. 13 is a graph showing the counter electromotive force according to each phase of the motor with a rotor, FIG. 13 is a graph showing the torque generated in the motor with a rotor according to another embodiment of the present invention, and FIG. 14 is another embodiment of the present invention. It is a graph showing the torque of the motor with a rotor according to the motor with a rotor according to the prior art.

As shown in FIG. 10, the rotor of the electric motor according to the present embodiment is inclined in a direction opposite to the magnetic pole center of the magnet 42 to face the barrier 44 and is formed to extend in the radial direction of the rotor 4. 45 'is formed, and the configuration other than the guide hole 45' is the same as the embodiment of the present invention, and the same reference numerals are used, and detailed description thereof will be omitted.

The magnetic flux flow is formed in the core 43 of the rotor 4 and the teeth 33 of the stator 3 by the magnet 42 as shown in FIG. 11 at no load, and at this time, the magnet ( Some of the magnetic flux generated at 42 is in the form of a closed curve that circulates around the barrier 42 using the space between the magnet 42 and the void 37.

Here, as the guide hole 45 'is inclined in the direction opposite to the magnetic pole center of the magnet 42 toward the barrier 44, a part of the effective magnetic flux toward the tooth 33 is the guide hole ( 45 ') guides the barrier 44 to become a leakage magnetic flux, which eventually increases the leakage magnetic flux.

Looking at the operation of the present invention configured as described above are as follows.

12 is a graph showing the back EMF waveform of each phase over time when the motor rotates about 1100 RPM. The thick solid line, the thin solid line, and the broken line each show the back EMF of each of the three phases. The counter electromotive force waveform indicates that the flat portion in the counter electromotive force graph is wider than the waveform in the conventional electric motor shown in FIG.

FIG. 13 is a graph showing a time-dependent torque generated when an ideal current to which a three-phase delta connection is applied is input in a counter electromotive force waveform as shown in FIG. 11, and a thin solid line at the bottom represents torque for each phase and The thick solid line represents the sum of the torques for each phase. Compared with the conventional electric motor, as shown in FIG. 14, the flat portion of the back EMF waveform becomes wider, and the difference between the maximum and minimum values of torque becomes smaller, and torque ripple. It can be seen that this is reduced.

Here, when the average torque and the maximum and minimum torque according to the torque according to FIG. 14 are compared and calculated, it is shown in Table 3 below.

TABLE 3

talk Conventional electric motor Another embodiment Average torque 1.88 Nm 1.84 Nm Torque 1.96 Nm 1.90 Nm Torque 1.64 Nm 1.81 Nm The difference between the maximum and the minimum 0.32 (17% of average torque) 0.09 (5% of average torque)

As shown in Table 3, the average torque value is 1.84 Nm, which is about 2%, and the maximum torque value is 1.90 Nm, which is decreased by about 3%, but the minimum value is increased by about 10%, and the difference between the maximum and minimum values is 0.09 5% of torque), the difference is reduced by about 72%.

On the other hand, since the shape, number and the slope and length of the guide holes 45, 45 'should be determined through several experiments and their interpretation, the present invention is not limited to the above two embodiments, The rotor of the electric motor provided in a shape having a different length corresponds to the present invention.

The rotor of the motor according to the present invention configured as described above can adjust the amount of magnetic flux generated in the magnet to the stator through the process step of adding a guide hole without additional components in manufacturing the motor There is an advantage that can be responded to only by changing the design of the guide hole according to the purpose of use of the motor.

In particular, the rotor of the electric motor formed between the magnet and the air gap near each magnetic pole and inclined toward the magnetic pole center of the magnet has an effective magnetic flux to increase the average torque and the maximum torque value, and greatly reduce the torque ripple. There is an advantage.

In addition, the rotor of a motor with a guide hole inclined in a direction opposite to the magnetic pole center of the magnet has an effective magnetic flux amount to decrease the average torque and the maximum torque value, but the difference between the minimum torque value and the maximum torque value is remarkable. In other words, the torque flat portion is widened, and the torque ripple is reduced.

Claims (6)

A rotor of an electric motor, in which a plurality of magnets are radially inserted in a circumferential direction of a core, and a magnetic flux barrier for blocking magnetic flux is formed between the magnets; The rotor of the motor, characterized in that the guide hole is further formed to induce magnetic flux in the vicinity of the barrier. The method of claim 1, The guide hole is located between the magnet and the gap of the rotor, the rotor of the electric motor, characterized in that formed in the vicinity of both magnetic poles of the magnet. The method of claim 1, The guide hole is a rotor of the electric motor, characterized in that formed long in the radial direction of the rotor. The method of claim 1, The rotor of the motor, characterized in that a plurality of guide holes are formed by the number of magnetic flux leaked. The method according to claim 1, wherein The guide hole is a rotor of the electric motor, characterized in that positioned inclined toward the magnetic pole center of the magnet. The method according to claim 1, wherein The guide hole is a rotor of the electric motor, characterized in that inclined in the direction opposite to the magnetic pole center of the magnet.

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