KR100923794B1 - Method for manufacturing of soltless motor stator using magnetic anisotropic of non-oriented electrical steel sheet - Google Patents

Abstract

The present invention relates to a stator for a slotless motor using the magnetic anisotropy of a non-oriented electrical steel sheet and a method for manufacturing the same. A slot having no tooth and slot structure by stacking a non-uniform electrical steel sheet having a uniform permeability by magnetization direction. In the manufacturing method of a stator for a lesser motor, it characterized by laminating | stacking the sheet | seat of the said non-oriented electrical steel sheet by the rotation angle determined from the period of magnetic anisotropy and the total number of laminated sheets. By the above configuration, the present invention has the effect of preventing local saturation in the stator core to increase the effective magnetic flux of the motor, thereby achieving high efficiency, high output, and small weight of the motor.

Non-oriented electrical steel sheet, stator, magnetic anisotropy, lamination, motor

Description

Stator for slotless motor using magnetic anisotropy of non-oriented electrical steel sheet and manufacturing method thereof {METHOD FOR MANUFACTURING OF SOLTLESS MOTOR STATOR USING MAGNETIC ANISOTROPIC OF NON-ORIENTED ELECTRICAL STEEL SHEET}

The present invention relates to a stator for a slotless motor using magnetic anisotropy of non-oriented electrical steel sheet. In particular, in the inherent magnetic anisotropy of the material when the core is laminated, the magnetic properties such as magnetic permeability have a good position. The present invention relates to a stator for a slotless motor using a magnetic anisotropy characteristic of a non-oriented electrical steel sheet which allows a magnetic flux to pass smoothly by rotating and stacking each layer, and a manufacturing method thereof.

In general, a motor is composed of a conductor for supplying power and an iron core provided in a mechanism capable of mounting the conductor, and each component serves as a path for transmitting electric energy and magnetic energy. At this time, the magnetic material constituting the magnetic circuit in the mechanism determines the performance of the motor, the electrical steel sheet of the magnetic material has been adopted in most motors as an important functional material used as a path of magnetic flux in the motor.

In particular, as the industrial system is diversified and the demand for energy saving is increased, various power converters are increasing in output, high efficiency, and high performance. In response, electric steel sheets and high magnetic flux density low iron loss products are being developed.

Among the motors using such steel sheets, the slotless motor can reduce the stator size because there is no slot, and also has the advantage of reducing vibration noise because there is no cogging torque generated by the structure of the tooth and the slot. It is widely used as a small precision motor in the fields of information and communication and medical devices such as, chip grinder and vibrator.

1 is a conceptual diagram showing the structure of a slotless motor, Figure 2 is a conceptual diagram showing a conventional stator stacking method.

The stator 1 as shown in FIG. 1 is mainly used by stacking 10 sheets of electrical steel sheet cores as shown in FIG. 2, where the magnetic flux 5 due to the permanent magnet 2 is a stator iron core. Each laminated iron passes uniformly through. The rotor is composed of a permanent magnet (2), a rotating shaft (4), a rotor iron core (3), bearings are provided at both ends of the rotating shaft (4) to be rotatable.

As shown in FIG. 2 (a), in general, when stacking each sheet in parallel to the rolling direction 6 when stacking the core of the stator, the height between the products is different or the stacked cores are tilted to one side. This occurs because the thickness of the electrical steel sheet in the rolling direction is not constant.

In order to prevent such defects, the first sheet is laminated in the rolling direction 0 [deg.] When the stator iron core is laminated, and the second sheet is laminated in the 90 [deg.] (Or 180 [deg.]) Direction perpendicular to the rolling direction (7). From the beginning, they are alternately stacked in the same way. The 90-degree or 180-degree rotational lamination is merely to improve the lamination failure due to the mechanical deviation of the electrical steel sheet and has nothing to do with improving the performance of the motor through the improvement of the magnetic properties. FIG. 2 (b) shows a schematic diagram of a 90 degree rotational lamination, and FIG. 2 (c) shows a 180 degree rotational lamination.

3 is a graph showing the magnetic permeability of the non-oriented electrical steel sheet according to the magnetization direction.

As shown in FIG. 3, the electrical steel sheet has magnetic anisotropy in which magnetic permeability differs for each magnetization direction. Here, the change of the permeability 8 by the magnetization direction from the rolling direction 0 degree to the rolling perpendicular direction 90 degree on the r-θ plane when applying 800 [A / m] magnetic field, where the x axis is the rolling direction y axis is the permeability.

When the sheets of stator cores are stacked in the same direction by using electrical steel sheets having such magnetic properties, the magnetic permeability is inversely proportional to the permeability because the magnetic permeability of the stator's 30-degree gyros is the smallest. Occurs, and the total amount of magnetic flux passing through the iron core is reduced. The amount of magnetic flux φ passing through the iron cores of each sheet in the stator iron cores in which N pieces are stacked is obtained by dividing the total magnetic flux amount Ψ by the number of sheets N, and a uniform magnetic flux passes through each sheet.

However, the conventional method for manufacturing a stator for a motor has higher magnetic steel anisotropy as a high-grade electrical steel sheet, and thus, when laminating stator cores using high-grade steel, there is a problem that stagnation phenomenon such as local saturation becomes larger.

The present invention has been proposed to solve the above problems, focusing on magnetic anisotropy different in magnetic permeability according to the magnetization direction of the non-oriented electrical steel sheet in the stacking while rotating the stator iron core to a good magnetic permeability, the magnetic flux is high permeability It is an object of the present invention to provide a stator for a slotless motor using magnetic anisotropy of non-oriented electrical steel sheet capable of preventing local saturation and increasing magnetic flux by forming a three-dimensional magnetic flux path to pass through layers. .

The present invention for achieving the above object is a method of manufacturing a stator for a slotless motor stator having a structure of teeth and slots by stacking non-uniform electrical steel sheet having a uniform permeability by magnetization direction, and the period of magnetic anisotropy and It is characterized in that the stacking while rotating the sheets of the non-oriented electrical steel sheet by the rotation angle determined from the total number of sheets.

Preferably, the rotation angle may be 90 / (N-1) when the total stacking number is N.

Preferably, the rotation angles of the layers may be sequentially laminated so that K is (K-1) × 90 / (N-1) when K is the stacking order.

Stator for a slotless motor using the magnetic anisotropy of the non-oriented electrical steel sheet according to the present invention and a method for manufacturing the stator of the slotless motor without a tooth and slot structure using a high-quality non-oriented electrical steel sheet and the magnetic anisotropy period and lamination By laminating while rotating at a rotation angle determined from the relationship of the number of sheets, it is possible to prevent local saturation in the stator core to increase the effective magnetic flux of the motor, thereby achieving high efficiency, high output, and small size of the motor.

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

The present invention is a method of manufacturing a stator for a slotless motor having no tooth and slot structure by stacking non-uniform electrical steel sheets having a uniform permeability by magnetization direction, the rotation angle determined from the period of magnetic anisotropy and the total number of stacked sheets. The sheet of the non-oriented electrical steel sheet is laminated while rotating.

In other words, when rotating stator cores, the rotation angle θ of each sheet becomes 90 / (total number of sheets-1), the rolling direction of the first sheet is laminated at 0 degrees, and the second core is rotated by θ so that the top of the first core is rotated. Lamination is carried out in this manner, and the lamination is sequentially performed in this manner, and the lamination angle of the final final sheet is laminated at 90 degrees.

Hereinafter, with reference to Figure 4 will be described the effect of the performance of the rotary lamination of the electrical steel sheet having magnetic anisotropy.

Figure 4 is an illustration of the magnetic flux path during the rotary lamination of the magnetic anisotropic electrical steel sheet.

As shown in FIG. 4, the stator iron cores stacked in two sheets were cut and unfolded to show 0 to 90 degrees. Here, the stator cores are divided into three sections, 0 ~ 30 degrees, 30 ~ 60 degrees, and 60 ~ 90 degrees, and the average permeability in each section is shown.

When stacked by the conventional method as shown in Fig. 4 (a), the magnetic flux passing through each layer is the same because the first layer and the second layer have the same permeability, and the locality is between 30-60 degree intervals with poor permeability. Saturation occurs.

As shown in FIG. 4 (b), when the second sheet is rotated by 30 degrees, the magnetic flux of the first sheet and the second sheet is the same in the 0 to 30 degrees section, and thus the same amount of magnetic flux is transmitted. Since the permeability of the field is worse than that of the second chapter, part of the magnetic flux passes through the high permeability of the second chapter, and at 60-90 degrees, the magnetic flux passes through the high permeability of the first chapter, thereby reducing the total magnetoresistance of the magnetic circuit. It is possible to prevent local saturation and to increase the flux through the iron core compared to the conventional lamination method.

5 is a schematic diagram showing a stator iron core stack manufacturing method according to an embodiment of the present invention.

FIG. 5 is an exemplary schematic diagram showing the angle of rotation in each layer of a stator iron core having N number of stacked sheets, and is shown on a slit electrical steel sheet 9 used for punching or cutting stator iron core using a real mold or the like. It was.

In the case of the stator having N sheets, the rotor angle of the Kth sheet is (K-1) × 90 / (N-1), so that the rolling directions of the laminated iron cores are all placed in different directions. Lay in the direction.

As is well known, electrical steel sheet is divided into oriented electrical steel sheet and non-oriented electrical steel sheet, and directional electrical steel sheet refers to a steel sheet arranged in one direction to facilitate magnetization in the rolling direction, and is mainly used for stops such as transformers and reactors. Non-oriented electrical steel sheet refers to a steel plate made to be easy to magnetize in all directions, and is mainly used for a rotor such as a motor.

On the other hand, high-quality non-oriented electrical steel sheet has a non-isotropic magnetic property of each magnetization direction is not uniform isotropic, as shown in FIG. It has a bad effect on the performance of the same motor.

The present invention utilizes this magnetic anisotropy to improve motor performance through rotational lamination.

When rotating the stator of the slotless motor at 90 / (N-1) degrees, the magnetic flux has a three-dimensional path passing between the sheets. Therefore, in the present lamination method, the thinner the electrical steel coating layer, the easier the magnetic flux is moved between sheets, and thus the motor performance improvement effect is useful, or the greater the difference in magnetic properties in each direction, that is, the greater the difference in magnetic anisotropy, the greater the effect. appear.

At this time, the iron core and the permanent magnet shape of the rotor is not particularly limited, for example, can be applied regardless of the number of poles, the arrangement of the permanent magnet, the shape and dimensions of the iron core, as well as improve the additional function of the slotless motor In the case of attaching or inserting a permanent magnet inside the rotor for having a conductive conductor bar or employing a driver for controlling the motor, the present invention can be applied to both.

In addition, it can be applied to the automatic lamination at the time of lamination in consideration of productivity. Here, the punching method in the production of the iron core can be a method such as a mold or wire gating, and the laminating method is caulking, interlocking, clips, welding, bolting, Bonding and the like are also possible.

Hereinafter, an Example is described.

EXAMPLE

Samples were prepared in the same manner as the method according to the present invention with iron cores in the form of Troidal rings similar to slotless stator structures using non-oriented electrical steel sheets. Here, the thickness of the electrical steel sheet is 0.5mm, the size of the test specimen is 100mm inner diameter, 110mm outer diameter, the total number of sheets is 10 sheets.

Here, in the present embodiment, the lamination was rotated at intervals of 10 degrees (= 90 / (10-1)) between layers, and the comparative example according to the conventional method was laminated so that the rolling directions were all consistent without rotation. Table 1 compares the magnetic flux densities of the two samples, and shows a high magnetic flux density (magnetic flux) of the samples laminated by the method of the present example.

division H = 100 [A / M] H = 500 [A / M] Example 0.96 1.46 Comparative example 0.94 1.45

1 is a conceptual diagram showing the structure of a slotless motor.

2 is a conceptual diagram showing a conventional stator lamination method.

Figure 3 is a graph showing the magnetic permeability of the non-oriented electrical steel sheet by direction.

Figure 4 is an illustration of the magnetic flux path during rotational lamination of magnetic anisotropic electrical steel sheet.

Figure 5 is a schematic diagram showing a method for manufacturing a stator iron core stack according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

1: stator 2: permanent magnet

3: rotor iron core 4: rotor shaft

5: magnetic flux 6: rolling direction

7: rolling perpendicular direction 8: permeability

9: slitting electrical steel sheet 10: lamination

Claims (4)

In the method of manufacturing a stator for a slotless motor having no structure of teeth and slots by laminating non-oriented electrical steel sheets having non-uniform permeability per magnetization direction, It is laminated while rotating the sheet of the non-oriented electrical steel sheet by the rotation angle determined from the period of magnetic anisotropy and the total number of laminated sheets, wherein the rotation angle is 90 ° / (N-1) when the total number of laminated sheets is N A stator manufacturing method for a slotless motor using magnetic anisotropy of non-oriented electrical steel sheet. delete The method of claim 1, Non-oriented electrical steel sheet having a stacking order of K is sequentially stacked such that the sheets are laminated at an angle of (K-1) × 90 ° / (N-1). Method for manufacturing stator for motor. In the stator for a slotless motor formed by stacking non-oriented electrical steel sheets having non-uniform permeability per magnetization direction, Non-oriented electrical steel sheet of the non-oriented electrical steel sheet, characterized in that the non-oriented electrical steel sheet having a stacking order of K when the total number of sheets is N is laminated to form an angle of (K-1) × 90 ° / (N-1) Stator for slotless motor using characteristics.

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