KR101140614B1 - Stator core for pole-shifting and electric machine comprising the same - Google Patents

Abstract

The present invention relates to a stator core structure of an electric motor, and more particularly, to a structure of a stator core formed to reduce torque ripple and cogging torque without employing a skewing technique for forming a twist in the stator core, and including the same. It relates to an electric motor.
To this end, the present invention provides a stator core having a plurality of teeth for one phase and an electric motor including the same, wherein the stator core is misaligned at a predetermined angle with a reference tooth aligned to a corresponding rotor pole. The present invention provides a stator core composed of a plurality of stator tooth modules including a pole shift tooth and an electric motor including the same.
According to this configuration, in the present invention, the generated torque ripple and cogging torque can be reduced to greatly reduce the vibration of the motor, and the difficulty of manufacturing due to skew is solved, thereby improving the productivity and reducing the cost.

Description

Stator core for pole-shifting and electric machine comprising the same

The present invention relates to a stator core structure of an electric motor, and more particularly, to a structure of a stator core for reducing cogging torque and torque ripple of an electric machine and an electric machine including a stator core of such a structure.

In general, electrical equipment refers to an energy converter that converts electrical energy into mechanical energy or mechanical energy into electrical energy, and includes an electric motor, a generator, and the like, and various types of electrical devices are used to improve efficiency and power density. Is being developed.

An example of an electric device for enhancing power density is an electric device having a structure in which a magnetic force flux (hereinafter referred to as a magnetic flux) is formed in a vertical plane in a moving direction of the mover, and may also be called a transverse flux electric device or a transverse flux device. do.

In such a transverse flux machine, a stator is composed of a stator core and a coil composed of yokes and teeth, and a rotor is formed of a rotor core. ) And permanent magnets. Since this is an example of the basic structure, the coil may be located on the rotor instead of the stator, and the permanent magnet may also be located on the stator instead of the rotor.

On the other hand, as a technique for reducing cogging torque in a general electric motor, there is a skewing technique to reduce cogging torque. This skewing technique is characterized in that the stator forms the magnetic poles in an obliquely inclined pattern such that the stator has a rotational position that is relatively displaced along the axial direction of the rotor. To this end, the skewing technique provides skew to the yoke and teeth of the stator, or to the rotor core and permanent magnet.

If the lamination is made in the axial direction as in the seed flux motor, it is inconvenient to wind the coil and does not cause a big problem in forming skew in the core. Since the coil is disposed between the teeth arranged in the rotational direction, the winding cross-sectional area is not reduced, and the skew shape can be easily given by simply forming the skew shape using an auxiliary and then stacking the core in the axial direction.

However, in the case of a transverse flux motor in which the magnetic flux flows in a direction perpendicular to the moving surface, that is, in the axial direction, the stacking is performed in the moving direction, the skew is formed in the same concept as that of the seed flux motor. In addition, it can be a problem in forming the core.

1 shows an example of a stator core of a transverse flux motor manufactured by a skewing technique according to the related art, and includes a stator core having a stator tooth having a skew structure for reducing cogging torque and torque ripple. It is shown.

As shown in FIG. 1, the value of the skew structure is inclined by a predetermined angle with respect to the central axis of the inner core 13, whereby a predetermined skew angle at the stator teeth 11 is obtained. It is set to reduce cogging torque and torque ripple.

The skew structure as described above is shown in more detail in the attached side view of FIG. 2. Specifically, FIG. 2 illustrates a side view of the yoke 12 and the teeth 11 formed by being stacked in a twisted shape with respect to the central axis of the stator core, and the shapes of the teeth sequentially stacked in the skewed structure. can confirm.

On the other hand, in this skewing technique, in order to manufacture a stator core having a torsional layered structure, the iron core (steel plate) constituting the core is cut (punched) and the iron core is twisted and then processed. The iron cores must be laminated and fixed. At this time, the twisting process and the lamination process may be reversed (torsion after lamination). As a method of fixing the iron core, a welding method or a method of molding the whole with a material such as a resin is used. A stator including a tooth and a slot is placed on the circumferential surface of the inner core to be aligned at a desired position. To form a core.

In addition, in the case of twisting the rotor, the rotor core and the permanent magnet should be manufactured in the form of torsion.

However, the skewing technique of providing a twist to the stator core or the rotor (mover) core as described above causes various problems in forming the skew structure and assembling the formed skew structure in a desired position. do.

First, there is a problem in that a process for forming a skew structure with respect to teeth is necessary and thus productivity is lowered and manufacturing costs are increased.

In addition, in forming a skew structure that reduces cogging torque, there is a problem in that the stacking efficiency is lowered when the skew structure is formed by twisting an iron plate so as to effectively secure an effective cross section in a gap where a force is generated. .

Referring to the problems associated with the skewing structure in detail with reference to the accompanying FIG. 3, as compared with the case of laminating a non-skewed smooth steel plate, as in the accompanying FIG. In the case of laminating one iron plate, a space is easily formed between the stacked iron plates, and as shown by the region C shown in FIG. This is necessary and the process is complicated.

On the other hand, in the case of forming the skew structure after lamination, an invalid cross-sectional area occurs as shown in the region B shown in Fig. 3 (b), so that the effective winding cross-sectional area between the teeth arranged up and down is reduced, and rather unnecessary protrusion is performed. There was also a problem that post processing is necessary because of the area.

Thus, skewing techniques for forming skew structures to reduce cogging torque have to go through a difficult process that provides twisting, as well as technical limitations that are unsuitable for mass production due to the post-processing required in the lamination and skewing process.

The present invention has been made to solve the above problems, in the present invention, in the stator core having a plurality of teeth (phase) for a single phase (electric) and an electrical device comprising the same, the corresponding rotor magnetic pole Mass production in a simple process by providing a structure of a stator core consisting of a plurality of stator tooth modules comprising a reference tooth aligned in the and a pole shift tooth misaligned at an angle. The present invention provides a stator core and an electric device including the same.

In order to achieve the above object, in the present invention, in the stator core formed with a plurality of teeth for one phase, the plurality of teeth is a reference value aligned to the reference line (S) of the corresponding rotor poles to face the rotor poles A pole shifted stator core is characterized in that the pole shift teeth are misaligned with the teeth and the baseline S.

In addition, the stator core is composed of a 'c' shaped cross-sectional structure including a yoke, an upper tooth and a lower tooth, wherein the upper tooth and the lower tooth are alternately opposed to the rotor magnetic pole in sequence, the pole moved stator core To provide.

In addition, the pole shifted tooth provides a pole shifted stator core, characterized in that a plurality of teeth continuously arranged relative to the clockwise or counterclockwise direction of the reference tooth along the outer periphery of the stator core.

In addition, the pole shift value provides a pole shifted stator core, characterized in that a plurality of teeth arranged to be sequentially moved by the pole shift angle (α) sequentially from the reference value.

The reference tooth and the plurality of pole movement teeth form a stator tooth module that is continuously pole-moved, and a plurality of such stator tooth modules are combined to form a stator core.

On the other hand, in the present invention, in the electric machine comprising a stator core formed with a plurality of teeth for one phase, the stator core is a reference value (aligned to the reference line (S) of the corresponding rotor poles so as to face the rotor poles ( It provides an electrical device comprising a stator core, characterized in that it is a stator core comprising a plurality of teeth including teeth and pole shift teeth (teeth) misaligned in the baseline (S).

In addition, the stator core is a 'c' shaped cross-sectional structure including a yoke, an upper tooth and a lower tooth, characterized in that the upper and lower teeth are a stator core configured to alternately face the rotor poles in sequence It provides an electrical device comprising a stator core that is poled.

In addition, the pole movement tooth provides an electric device comprising a pole movement stator core, characterized in that a plurality of teeth continuously arranged with respect to the clockwise or counterclockwise direction of the reference tooth along the outer periphery of the stator core.

In addition, the pole shift value provides an electric device including a pole shifted stator core, characterized in that the plurality of teeth arranged to be sequentially moved by the pole shift angle (α) from the reference value.

The reference device and the plurality of pole movement teeth form a stator tooth module that is continuously pole-moved, and a plurality of such stator tooth modules are combined to form a stator core. To provide.

As described above, the pole-moved stator core and the electric apparatus including the same have an effect of reducing the torque ripple and the cogging torque by reducing the stator teeth of the stator core to reduce the vibration of the electric apparatus.

In addition, unlike the conventional skewing technique, since the stator core can be manufactured simply by adjusting the arrangement of the stator teeth without providing a constant twist, after forming the skew structure and the skew structure, All post-processing processes that have been performed can be excluded, resulting in increased productivity and reduced costs.

1 is a schematic diagram of a stator core skewed according to the prior art;
2 is a side view showing the shape of a stator core skewed according to the prior art;
Figure 3 is an enlarged side view showing a portion where post-processing is required after skewing according to the prior art.
4 is a perspective view showing a part of the pole moved stator core and the rotor according to the present invention.
5 is a plan view showing a part of the pole moved stator core and the rotor according to the present invention.
Figure 6 is a torque change graph for the pole shift angle change in a preferred embodiment of the present invention

The present invention for achieving the above object, unlike the conventional skewing technology, and provides a stator core and an electric device including the same so as to easily reduce the torque ripple and cogging torque while being easy to manufacture in a simple structure.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this application, the terms “comprises” or “having” are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other It is to be understood that the present invention does not exclude the possibility of the presence or the addition of features, numbers, steps, operations, components, parts, or a combination thereof.

Particularly, in the present invention, the structure of the stator core is described based on a rotary motor, but both the motor and the generator, and the rotary and linear electric devices may be applied in the same manner as the rotary motor described below. Will be readily understood by those skilled in the art.

Hereinafter, with reference to the accompanying drawings as a preferred embodiment of the present invention, it will be described in detail with an example of a rotary electric motor as follows.

FIG. 4 is a perspective view showing a stator core and a rotor corresponding thereto, which are pole moved according to the present invention, and FIG. 5 is a plan view of such a stator core and a rotor.

As is well known, the stator core in the present invention is used to construct a stator such as an electric motor. As shown in FIG. 4, in particular, an abduction type motor, for example, the yoke 130 and the teeth 110 and 120 are illustrated. A coil (not shown) is wound around the stator core 100 configured to form a stator. In addition, a rotor 200 in which a permanent magnet 220 and a soft magnetic powder (Soft Magnetic Composite, SMC,) core 210 are combined is disposed outside the stator core of the abduction type electric motor, and the rotor has the stator core. It is spaced apart from 100 at predetermined intervals. Although not shown separately in the permanent magnets constituting the rotor, the permanent magnets 220 are arranged to have different magnetic poles around the soft magnetic powder core 210.

The stator core included in the motor according to the present invention is a stator core formed to have a plurality of teeth with respect to one phase, and includes a plurality of teeth 110 and 120 corresponding to the soft powder core. do. In the stator core according to the preferred embodiment of the present invention, the cross section of the cross section of the stator core 100 for each phase is formed to have a 'c' shape, and the plurality of teeth have a 'c' shape image? It consists of an upper tooth 110 and a lower tooth 120 respectively formed in the lower portion so that the upper tooth 110 and the lower tooth 120 are alternately opposed to the rotor magnetic pole.

That is, as shown in Figure 4 showing the stator core and the rotor according to an embodiment of the present invention, the teeth and slots (150) in the upper and lower portions of the yoke for the stator core Configured to repeat. The arrangement of the upper and lower teeth is shown in more detail in FIG. 5, which shows a plan view thereof, in which the stator core is configured such that the lower teeth are disposed at positions of slots formed between upper teeth.

On the other hand, unlike the conventional structure of an arrangement in which the rotor poles and stator teeth are aligned without the conventional pole movement, a plurality of teeth formed in the stator core according to the present invention are pole-moved to the corresponding rotor poles. It is composed.

Pole shift in the present invention means that the stator teeth are relatively misaligned from the reference line of the corresponding rotor poles.

Therefore, in the present invention, the stator teeth aligned with respect to the reference line S with the rotor poles are referred to as reference values, and the stator teeth misaligned with the reference line S and moved by a predetermined angle are referred to as pole shift values. The stator core will contain these poleshift teeth.

These pole shift teeth may be appropriately combined with the reference teeth, and preferably arranged in combination with the reference teeth and the pole shift teeth in a predetermined rule to form a fixed array of stator tooth modules, while a number of such stator tooth modules Can be configured to form one stator core by repeating continuously.

For example, in the case of a motor including a rotor core having 60 rotor poles and six stator tooth modules, the number of stator teeth corresponding to the number of rotor poles is 30 at the top and the bottom, respectively. 6 modular stator cores corresponding to the number of 60 magnetic poles can be formed by repeatedly forming each of the 30 pairs of stator teeth in six modules.

On the other hand, in configuring the stator tooth module, the stator tooth module is configured to include a plurality of pole movement teeth arranged continuously in a clockwise or counterclockwise direction based on the aligned reference value, You can give an array some regularity.

Therefore, the stator tooth module composed of a plurality of pole shift teeth arranged consecutively with respect to the reference value is successively arranged so that the reference value and the pole shift value for the next module are continuously arranged in the same arrangement to form one stator core.

At this time, in the reference value and the pole movement value constituting the stator tooth module, the pole movement value is formed so that the pole movement is arranged from the rotor magnetic pole by a predetermined angle, so that each pole movement tooth is adjacent to another pole movement tooth The pole shift angle α, which represents the degree of relative pole movement relative to the reference value (or reference value), may be selected in a suitable range according to the designed motor.

Preferably, in constructing the stator tooth module, each of the pole shifting teeth that are continuously arranged in a clockwise or counterclockwise direction from the aligned reference tooth is sequentially sequential by an angle according to the arrangement order of the amount of the pole shifted from the actual reference line. It can be configured to increase / decrease in this case, in which case the pole shift angle (α), which means the relative pole displacement relative to other stator teeth (reference value or pole movement value) adjacent to it, is constant.

On the other hand, the pole shift angle α in the present invention does not need to be kept constant in one stator tooth module, and may be appropriately changed according to the required performance. Therefore, it is possible to appropriately configure the arrangement of the pole shift values such that the pole shift angle α is set to a different value in one module.

Embodiments of the reference values and the pole movement values sequentially arranged with respect to the pole movement angle α set as described above will be described with reference to FIG. 5.

FIG. 5 is a plan view illustrating an example of a stator core having five upper and lower pairs of stator teeth gathered to form a module according to an exemplary embodiment of the present invention. As shown in FIG. 5, the stator tooth module is shown in FIG. Is a pair of reference teeth (110a, 120a) to the right, four pole movement teeth (110b, 110c, 110d, 110e) formed in the upper sequentially on the left side and four pole movement teeth (120b) formed in the lower portion , 120c, 120d, and 120e).

The stator tooth module formed as described above is given a regularity. Preferably, the stator tooth module may be formed to include a pair of pole movement teeth sequentially moved by a predetermined pole movement angle α while going from the reference value to the left.

That is, as shown in FIG. 5, the pair of first and second pole movement teeth 110b and 120b which are closest to the left side of the reference tooth in the plan view are disposed at positions that are pole-shifted by α, and on the left side thereof. The pair of upper and lower side positioned second pole movement teeth 110c and 120c are formed in such a manner that they are arranged in positions of pole movement by 2α. Therefore, in the case of the fourth pole shift teeth 110e and 120e on the leftmost side formed in the leftmost module in one module, the position of the fourth pole shift teeth 110e and 120e is shifted by 4α with respect to the reference line S with the corresponding rotor pole. Configured to be deployed. Therefore, in the case of the stator tooth module of this arrangement, it is possible to configure such that the amount of pole movement angle compared to other adjacent stator tooth T pair is constant.

Since one stator tooth module configured as described above is followed by another stator tooth module of the same arrangement, the left side of the pair of fourth pole shift teeth at the point where one module ends, as shown in FIG. The reference value included in the following stator tooth module is located, and a stator core including a plurality of modules is configured in this manner.

Meanwhile, FIG. 6 shows a graph showing three-dimensional finite element analysis data for an embodiment of a motor including a pole shifted stator core according to the present invention in comparison with a motor including a stator core not shifted. have.

The motor in the analysis of FIG. 6 is made of a 60-pole electric motor consisting of six modules with 60 rotor poles and a corresponding 30 pairs of stator teeth. The pole shift angle (maximum pole shift angle: 0 degrees, 1.2 degrees, 2.4 degrees and α calculated the change of cogging torque according to the change of 0 degree, 0.3 degree, and 0.6 degree, respectively.

Looking at the analytical data in the motor according to such an embodiment, as shown in Figure 6, compared to the original non-polar shift (original), in the embodiment (1.2_shifting) that is relatively shifted at an angle of 1.2 degrees It can be seen that the graph of the change in the reduced cogging torque, and also in the embodiment (2.4_shifting) polarized by 2.4 degrees can be confirmed the tendency of the reduced cogging torque.

In addition, although not shown, the decreasing tendency of the cogging torque is gradually increased as the pole is moved from the aligned case, but as shown in the example of FIG. 6, the decreasing tendency of the cogging torque is better than that of the 1.2 degree at the pole shift angle of 2.4 degrees. As can be seen, the best torque reduction is achieved at certain pole travel angles.

This is the same as showing the optimum torque reduction at a particular skew angle, and designers can select and design the motor or generator as appropriate.

While the invention has been described with reference to the preferred embodiments, those skilled in the art will appreciate that modifications and variations of the elements of the invention may be made without departing from the scope of the invention. In addition, many modifications may be made to particular circumstances or materials without departing from the essential scope of the invention. Accordingly, the invention is not limited to the details of the preferred embodiments of the invention, but will include all embodiments within the scope of the appended claims.

100: stator core 110: upper teeth
120: lower teeth 130: York
150: slot 200: rotor
210: soft magnetic powder core 220: permanent magnet
110a, 120a: reference value
110b, 110c, 110d, 110e, 120b, 120c, 120d, 120e: pole shift
S: baseline

Claims (10)

delete In a stator core having a plurality of teeth formed for one phase,
The plurality of teeth are reference teeth aligned with the reference line S of the corresponding rotor poles so as to face the rotor poles and pole shift teeth misaligned with the reference line S,
The stator core has a 'c' shaped cross-sectional structure including a yoke, an upper tooth and a lower tooth, and the upper and lower teeth are paired and sequentially opposed to the rotor magnetic poles.
The stator core according to claim 2, wherein the pole shift teeth are a plurality of teeth continuously arranged with respect to the clockwise or counterclockwise direction of the reference tooth along the outer circumference of the stator core.
The stator core of claim 3, wherein the pole shift values are a plurality of teeth arranged to be sequentially moved by the pole shift angle α from the reference value.
5. The pole shifted stator of claim 3, wherein the reference tooth and the plurality of pole shift teeth form a successive pole shifted stator tooth module, the plurality of stator tooth modules being combined to form a stator core. core.
delete In an electrical device comprising a stator core having a plurality of teeth formed on one phase,
The stator core includes a plurality of teeth arranged at a baseline (S) of the corresponding rotor poles so as to face the rotor poles and a pole shift tooth (teeth) misaligned at the baseline (S). Is the stator core containing the teeth of
The stator core is composed of a 'c' shaped cross-sectional structure including a yoke, an upper tooth and a lower tooth, and the pole is a stator core configured to sequentially face the rotor magnetic poles while pairing the upper tooth and the lower tooth. An electrical device comprising a moved stator core.
8. The electric machine of claim 7, wherein the pole shift teeth are a plurality of teeth continuously arranged with respect to the clockwise or counterclockwise direction of the reference tooth along the outer circumference of the stator core.
9. The electric machine of claim 8, wherein the pole shift values are a plurality of teeth arranged to be sequentially pole shifted by the pole shift angle α from the reference value.
10. The pole moved stator of claim 8 or 9, wherein the reference tooth and the plurality of pole shift teeth form a continuously poled stator tooth module, the plurality of stator tooth modules being combined to form a stator core. Electrical apparatus comprising a core.

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