KR101464601B1 - Dual Stator Type Electric Apparatus with Displaced Permanent Magnet - Google Patents

Abstract

The present invention relates to an electric device. Relates to an electric machine that can be used as a generator or a motor in connection with its use. One embodiment of the electric device according to the present invention includes a shaft rotatably installed; Wherein a plurality of permanent magnets are arranged in a first permanent magnet array along a circumferential direction on a first surface of the disk and a plurality of permanent magnets are arranged on a second surface located on an opposite side of the first surface, Wherein the permanent magnets are arranged in a second permanent magnet array along the circumferential direction, and the N pole or S pole permanent magnet arranged on the first face and the N pole or S pole permanent magnet arranged on the second face are aligned A rotor in which one of the first and second permanent magnet arrays is transposed at a predetermined angle along the circumferential direction of the shaft with respect to the other one of the first and second permanent magnet arrays; And a first stator and a second stator which are disposed respectively with the rotor therebetween and are provided with a plurality of slots in which coils are wound.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an electric device having a double stator structure in which a permanent magnet is moved,

The present invention relates to an electric device of a double stator structure in which the position of a permanent magnet is shifted. An electric device having such a structure can be used as a generator or a motor.

Generally, the structure of a generator or a motor includes a rotor and a stator and a housing for fixing them. In the case of a generator, for example, a magnetic flux generated in a permanent magnet provided on a rotor is linked to a stator, thereby generating an induction current in a coil included in the stator by electromagnetic induction. The same is true of motors. These generators or motors have a problem of cogging torque in the initial start-up.

Cogging Torque is a non-uniform torque in a generator or motor, and is a force in the direction of disengagement in which the magnetic energy of the generator device is moved to a position where the magnetic energy is minimum. The cogging torque is generated by the interaction of the permanent magnet of the rotor and the slot of the stator.

In recent years, an economical and environmentally friendly compact wind turbine generator is in the spotlight. When a large cogging torque is required for a generator such as a small wind turbine generator, a large starting torque is required at the time of initial startup.

If the cogging torque is large, there is a problem that the efficiency and the output characteristic of the generator also deteriorate.

In addition, a conventional generator (Korean Utility Model Publication No. 2008-0070161, published on Jul. 30, 2008) generates heat when an electric induction action is generated between the rotor and the stator, there is a problem.

The above-described problem also occurs in the case of the motor.

For generators or motors, there is a need for generators or motors having an array of permanent magnets of a new construction in which the cogging torque is reduced.

Further, a generator or a motor having a structure that is not easily overheated is required.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. .

The electric device according to an embodiment of the present invention may include a shaft that is rotatably installed.

A plurality of permanent magnets are arranged in the first permanent magnet array along the circumferential direction on the first surface of the disk and a plurality of permanent magnets are arranged on the second surface located on the opposite side of the first surface. Wherein the magnets are arranged in the second permanent magnet array along the circumferential direction, and the N pole or S pole permanent magnet arranged on the first face and the N pole or S pole permanent magnet arranged on the second face are arranged in the direction of the shaft rotation axis One of the first and second permanent magnet arrays may be shifted at a predetermined angle along the circumferential direction of the shaft with respect to the other one of the first and second permanent magnet arrays.

Here, the cogging torque of the electric device according to the embodiment of the present invention is reduced by the movement of the permanent magnet, that is, the transition.

The first stator and the second stator may include a plurality of slots in which the coils are wound, the first stator and the second stator being disposed with the rotor therebetween.

Here, the rotor rotates between the first stator and the second stator so that it functions as a kind of cooling fan, so that the output or efficiency of the electric device according to the present invention is improved. This structure also has the effect of improving the durability of the electric device.

The first and second permanent magnet arrays may have N poles and S pole permanent magnets alternately arranged at a predetermined interval.

It is preferable that the gap is capable of linking the magnetic flux of the permanent magnet to the first and second stator.

The plurality of slots are arranged at predetermined intervals and may protrude in a direction in which the permanent magnets are positioned.

In some embodiments, the plurality of slots of the first stator and the plurality of slots of the second stator may be aligned along the rotational axis direction.

On the other hand, the transition angle may be determined by taking the number of the permanent magnets or the slots as a factor to reduce the cogging torque.

The transition angle (? _De ) can be calculated using the following equation.

(Equation)

α _de = (90 ° * HCF {N _s , P} / N _s ) ± 10 ° [deg.

Here, [deg. (E)] represents the electrical angle, N _s represents the number of slots provided in said second stator, each of the first stator, P is the first surface of the disk and the second side Denotes the number of the permanent magnets provided in each of them, and HCF {N _s , P} denotes the greatest common divisor of N _s and P. In the above equation, "± 10 °" represents an error range in the calculation of the transition angle.

The number of slots provided in each of the first stator and the second stator may be 30, and the number of permanent magnets provided on each of the first and second surfaces of the disk may be 20.

In an embodiment, the shaft is connected to a blade of a wind power generator and is capable of rotating by receiving power from the blade.

An electric device according to an embodiment of the present invention includes a first housing and a second housing that cover outer surfaces of the first stator and the second stator, respectively; And a third housing provided between the first housing and the second housing so that the plurality of permanent magnets and the plurality of slots maintain a predetermined gap.

Here, it is preferable that the gap is sufficient to link the magnetic flux of the permanent magnet to the first and second stator.

The electric device according to another embodiment of the present invention may include a shaft that is rotatably installed.

A plurality of permanent magnets are arranged in the first permanent magnet array along the circumferential direction on the first surface of the disk and a plurality of permanent magnets are arranged on the second surface located on the opposite side of the first surface. Wherein an N pole or S pole permanent magnet arranged on the first surface and an N pole or S pole permanent magnet arranged on the second surface are arranged in a second permanent magnet array along a circumferential direction, And may include an unaligned rotor along the direction.

The first stator may include a plurality of slots arranged to form a predetermined gap with the first surface of the rotor.

The stator of claim 1, further comprising a plurality of slots arranged in a predetermined gap with the second surface of the rotor, opposite the first stator and aligned with the plurality of slots of the first stator and the direction of the axis of rotation 2 stator.

The electric device of the above-described embodiment has the effect of reducing the cogging torque by changing the position of the permanent magnet, and also serves as a cooling fan while the rotor rotates, so that the cooling efficiency of the stator is excellent, It is effective.

Especially, in the case of a wind turbine generator and the like, the initial start-up is facilitated and the efficiency and output of the power generation are improved.

In addition, the effects of the present invention have various effects such as excellent durability according to the embodiments, and such effects can be clearly confirmed in the description of the embodiments described later.

1 is an exploded view showing a state where a rotor is inserted between a first stator and a second stator.
2 is a conceptual diagram for explaining how to make an N pole or S pole permanent magnet.
3 is a view showing a state before the position of the permanent magnet is changed.
4 is a view showing a state after the position of the permanent magnet is changed.

Hereinafter, embodiments of the electric device 10 according to the present invention will be described in detail with reference to the accompanying drawings. The electric device 10 here can be used as a generator or a motor.

1 is an exploded view showing a state in which a rotor 40 is inserted between a first stator 20 and a second stator 30. Fig. 2 is a conceptual diagram for explaining how to make N pole or S pole permanent magnets 43 and 44. Fig.

3 is a view showing a state before the positions of the permanent magnets 43 and 44 are changed. 4 is a view showing a state after the positions of the permanent magnets 43 and 44 are changed.

One embodiment of the electric device 10 of the present invention can function as a generator. Still another embodiment of the electric device 10 of the present invention can function as a motor.

Hereinafter, a case where the electric device 10 functions as a generator will be described as an embodiment of the present invention.

First, the present embodiment includes a shaft 50, a rotor 40, a first stator 20, and a second stator 30.

The shaft 50 is engaged with the rotor 40 and is rotatable together.

The first stator 20 and the second stator 30 are disposed with the rotor 40 therebetween. The first stator 20 is disposed facing the first side 41 of the rotor 40 and the second stator 30 is disposed facing the second side 42 of the rotor 40.

The first stator 20 and the second stator 30 are provided with a plurality of slots 21 and 31 on the disk. The plurality of slots (21, 31) are arranged along the circumferential direction of the disk. The plurality of slots 21 and 31 are arranged at predetermined intervals and protrude in the direction in which the permanent magnets 43 and 44 of the rotor 40 are located. The plurality of slots 21 of the first stator 20 and the plurality of slots 31 of the second stator 30 may be aligned along the direction of the rotation axis X of the shaft 50 depending on the embodiment. A coil 60 is wound around each of the plurality of slots 21 and 31.

The rotor 40 rotates between the first stator 20 and the second stator 30 due to the rotation of the shaft 50. This structure is advantageous in that the rotor 40 also functions as a cooling fan Thereby improving the cooling characteristics of the generator.

The rotor 40 includes a circular disk 40a having a first side 41 and a second side 42. [ The second side (42) is located on the opposite side to the first side (41). A plurality of permanent magnets 43 and 44 are arranged in the first permanent magnet array 45 along the circumferential direction on the first surface 41 of the disk 40a. A plurality of permanent magnets 43 and 44 are arranged on the second surface 42 in the second permanent magnet array 46 along the circumferential direction as in the first surface 41.

The first and second permanent magnet arrays 45 and 46 are alternately arranged in the N pole and the S pole permanent magnets 43 and 44, respectively. Here, the N-pole permanent magnet 43 or the S-pole permanent magnet 44 is configured to apply a magnetic field 72 in one direction to a magnetic body 70 having a magnetic moment 71 having no constant arrangement, Direction. That is, the N-pole permanent magnet 43 can be made by arranging the magnetic moments 71 so that the magnetic flux has a direction in which the magnetic flux exits, and the S-pole permanent magnet 44 is arranged in the reverse direction of the magnetic moment 71 so as to have a magnetic- .

Magnetic flux from the N-pole permanent magnet 43 goes out and enters the S-pole permanent magnet 44 through the stator 20 and 30, As a result, an induced current flows through the coils 60 of the stator 20 and 30 by the electromagnetic induction action to generate electric power.

The first and second permanent magnet arrays 45 and 46 are arranged such that the N pole permanent magnet 43 and the S pole permanent magnet 44 are alternately arranged at predetermined intervals. Here, if the interval is too narrow or too wide, the magnetic flux may not be bridged to the first and second stator 20, 30. Therefore, it is preferable that the interval between the N pole permanent magnet 43 and the S pole permanent magnet 44 is sufficient to link the magnetic flux to the first and second stator 20 and 30.

This embodiment is characterized in that the N pole or S pole permanent magnets 43 and 44 arranged on the first surface 41 and the N pole or S pole permanent magnets 43 and 44 arranged on the second surface 42 The first permanent magnet array 45 is moved along the circumferential direction of the shaft 50 so that the cogging torque is reduced with respect to the second permanent magnet array 46, . ≪ / RTI >

However, in other embodiments, the second permanent magnet array 46 may be transitioned at an angle (not shown) such that the cogging torque is reduced relative to the first permanent magnet array 45.

Cogging torque occurs in each of the first stator 20 and the second stator 30.

The generator according to the present embodiment shifts the cogging torque generated in the first stator 20 and the cogging torque generated in the second stator 30 by transferring the first or second permanent magnet arrays 45 and 46, It is possible to reduce the total cogging torque generated in the generator by the generator.

When the cogging torque is reduced, there is an effect that smooth start-up of the generator is achieved.

The angle? _De , i.e. the transition angle? _De , of the first or second permanent magnet arrays 45, 46 with respect to the second or first permanent magnet arrays 46, 45, It can also be expressed as an angle or as an electrical angle.

Here, the transition angle? _De can be determined by taking the number of the slots 21, 31 of the stator or the permanent magnets 43, 44 of the rotor 40 as factors to reduce the cogging torque.

In order to explain the expression (1) to 6 or less, N _c of the rotor 40 is called cogging torque generated number when the one rotation is, N _s is provided on each of the first stator 20 and second stator 30 P is the number of the permanent magnets 43 and 44 provided on the first surface 41 and the second surface 42 of the disk 40a and HCF {N _s , P is the greatest common divisor of N _s and P, α _c is the machine angle at which the cogging torque occurs once, α _ce is the electrical angle at which the cogging torque occurs once, and deg. (M) Τ _c is a total cogging torque, τ _cupper is a cogging torque generated in the first stator 20, τ _clower is a cogging torque generated in the second stator 30 , _C is a phase of the cogging torque, and? _De is a transition angle? _{De at} which the position of the first or second permanent magnet array 45 or 46 is changed.

Then, the number N _c of occurrences of the cogging torque per revolution generated in each of the first stator 20 and the second stator 30 can be expressed by the following equation (1).

Therefore, the machine angle for generating the cogging torque once can be expressed by the following equation (2).

Here, α _ce expressed by an electric angle of α _c is expressed by the following Equation 3.

Here, [deg. (E)] indicates that the N and S poles of the rotor 40 are connected to the slots 21 and 31 of the stator irrespective of the number of poles of the rotor 40. The cogging torque can be expressed by the sum of the cogging torque generated by the first stator 20 and the cogging torque generated by the second stator 30 as described in Equation (1).

The transition of the first or second permanent magnet array 45 or 46 is accomplished by a first or second permanent magnet array 45 or 46 as a method for reducing the cogging torque generated in each of the first and second stator 20, The phase of the cogging torque generated in the first stator 20 through the transition of the first and second stator 20 and 30 is shifted as shown in Equation (5), so that the sum of the cogging torque generated in the first and second stator 20 and 30 becomes zero The cogging torque generated when the first stator 20 is moved and the cogging torque generating phase is shifted 180 [deg. (E)) can be made zero.

Therefore, the transfer angle? _De of the first or second permanent magnet array 45 or 46, which moves the cogging torque phase generated by the first stator 20 by 180 [deg.], Can be expressed by the following equation (6).

In the expression (2),? _Ce is a function representing an electrical angle at which the cogging torque occurs once. When? _Ce is halved, the cogging torque has an electrical angle of 180 [deg. When the permanent magnets 43 and 44 arranged on the first surface 41 are moved by the transition angle? _De , the phases of the cogging torque generated in the first and second stator 20 and 30 are opposite to each other It can be seen that the cogging torque is canceled and thus the cogging torque of the generator is reduced.

Even if the number of slots 21 and 31 of the stator and the number of permanent magnets 43 and 44 are changed, the transition angle? _De of the first or second permanent magnet array 45 or 46 is calculated using Equation 6 Can be calculated.

The number of slots 21 and 31 provided in each of the first stator 20 and the second stator 30 may be 30, The number of the permanent magnets 43 and 44 provided on each of the two surfaces 42 may be twenty.

In this case, the experiment showed that the cogging torque was 2.89 [Nm] when the transition angle (α _de ) was 0 [deg. (E)] and 0.32 [Nm] when it was 30 [deg. That is, when the transition angle (α _de ) is given, the cogging torque is reduced.

The generator of the present embodiment may include a first housing 81 covering the outer side surface of the first stator 20 and a second housing 82 covering the outer side surfaces of the second stator 30, And a third housing 83 provided between the first housing 81 and the second housing 82. The third housing 83 serves to hold a plurality of permanent magnets 43 and 44 and a plurality of slots 21 and 31 in a predetermined gap 84. That is, the gap between the first stator 20, the rotor 40 and the second stator 30 is maintained so that the rotor 40 smoothly rotates between the first stator 20 and the second stator 30, The air gap 84 is maintained so that the magnetic flux generated in the permanent magnetic flux can sufficiently link the first and second stator 20 and 30.

Therefore, it is preferable that the gap 84 is such that the magnetic fluxes of the permanent magnets 43 and 44 can be adequately linked to the first and second stator 20 and 30.

In the generator of the present embodiment, the shaft 50 is connected to a blade (not shown) of the wind power generator and is able to rotate by receiving power from the blade.

If the cogging torque is large, a large starting torque is required at the time of initial starting of the wind power generator, so that the initial startup becomes difficult at a small air volume, and the efficiency and output characteristics of the generator also deteriorate.

However, according to the present embodiment, since the cogging torque is minimized through the movement of the permanent magnets 43 and 44, the initial startup of the wind turbine generator can be smoothly performed even in a small amount of air, It is effective.

However, the generator according to the present embodiment is not limited to the wind turbine generator, and can be applied to various applications in the electric device 10 which needs to reduce the cogging torque.

Another embodiment of the present invention is rotatable in combination with a shaft 50 and a shaft 50 that are rotatably installed and a plurality of permanent magnets 43 and 44 are provided on a first surface 41 of the disk 40a. And a plurality of permanent magnets 43 and 44 are arranged on the second surface 42 disposed on the opposite side of the first surface 41 in the same manner as the first surface 41. The permanent magnets 43 and 44 are arranged in the first permanent magnet array 45 along the circumferential direction, Pole permanent magnets 43 and 44 arranged on the first surface 41 and N poles 42 and 44 arranged on the second surface 42 are arranged in the second permanent magnet array 46 along the circumferential direction, Pole or S-pole permanent magnets 43 and 44 may include a rotor 40 that is not aligned along the direction of the rotation axis X of the shaft 50.

The first stator 20 and the second stator 20 of the rotor 40 are disposed to form a predetermined gap 84 with the first surface 41 of the rotor 40 and are provided with a plurality of slots Teeth 21, A plurality of slots 21 of the first stator 20 and a shaft X of the shaft 50 are arranged so as to face the first stator 20 and form a predetermined gap 84 with the surface 42, And a second stator 30 provided with a plurality of slots 31 aligned along the direction.

As described above, in the present embodiment, the case where the electric device 10 functions as a generator has been described. However, in the case where the electric device 10 functions as a motor as another embodiment of the present invention, the above- .

The electric device 10 according to the present invention can be applied to any device in which the electric device 10 having the structure for moving the position of the permanent magnets 43 and 44 can be employed.

While only a few are described above in connection with the embodiments of the present invention, various other forms of implementation are possible. The technical contents of the embodiments described above may be combined in various combinations as long as they are not incompatible with each other, so that they can be implemented in a new embodiment.

10: Electrical equipment
20: First stator
30: a second stator
40: Rotor
50: shaft
60: Coil

Claims (13)

A shaft rotatably installed;
A plurality of permanent magnets arranged in a first permanent magnet array along a circumferential direction on the first surface of the disk and a second permanent magnet array arranged on the opposite side of the first surface, A plurality of permanent magnets are arranged in a second permanent magnet array along the circumferential direction on the second surface, and an N pole or S pole permanent magnet arranged on the first surface and an N pole or S pole permanent magnet arranged on the second surface, One of the first and second permanent magnet arrays being transited at a predetermined angle along the circumferential direction of the shaft with respect to the other one of the first and second permanent magnet arrays based on an alignment position of the first permanent magnet array with respect to the shaft rotation axis direction; And
A first stator and a second stator, respectively disposed with the one rotor therebetween, and provided with a plurality of slots;
, ≪ / RTI &
Wherein each of the slots is formed by separating ends of adjacent slots from each other,
Wherein the plurality of slots of the first stator and the plurality of slots of the second stator are arranged in alignment along the rotational axis direction,
The predetermined angle may be,
A cogging torque generated between a permanent magnet arranged on a first surface of the disk and a slot provided in the first stator and a cogging torque generated between a permanent magnet arranged on a second surface of the disk and a slot provided in the second stator, The angles at which the torques cancel each other,
The number of the permanent magnets and the number of the slots is determined as a factor of consideration
. The method according to claim 1,
Wherein the first and second permanent magnet arrays are arranged such that N pole and S pole permanent magnets are alternately arranged at a predetermined interval. 3. The method of claim 2,
Wherein the gap is sufficient to link the magnetic flux of the permanent magnet to the first and second stator. The method according to claim 1,
Wherein the plurality of slots are arranged at predetermined intervals and protrude in a direction in which the permanent magnets are located. delete delete delete The method according to claim 1,
The transition angle (? _De ) is calculated using the following equation,
(Equation)
α _de = (90 ° * HCF {N _s , P} / N _s ) ± 10 ° [deg.
Here, [deg. (E)] represents the electrical angle, N _s represents the number of slots provided in said second stator, each of the first stator, P is the first surface of the disk and the second side And HCF {N _s , P} represents the greatest common divisor of N _s and P, respectively. The method according to claim 1,
Wherein the number of slots provided in each of the first stator and the second stator is 30, and the number of permanent magnets provided on each of the first surface and the second surface of the disk is twenty. The method according to claim 1,
Wherein the shaft is connected to a blade of a wind power generator and receives power from the blade and rotates. The method according to claim 1,
A first housing and a second housing that cover outer surfaces of the first stator and the second stator, respectively; And
A third housing provided between the first housing and the second housing to hold the plurality of permanent magnets and the plurality of slots in a predetermined gap;
The electric device further comprising: 12. The method of claim 11,
Wherein the gap is such that the magnetic flux of the permanent magnet can be bridged to the first and second stator. delete

Images