KR20100119188A - Coil for motor and brushless dc motor using the same - Google Patents

Abstract

PURPOSE: A coil for motor and brushless dc motor using the same is provided to reduce the effect on unique characteristics of the metal without additional separation work by using aluminum as the winding of a motor. CONSTITUTION: A brushless DC motor(100) comprises a rotor core(110), a plurality of permanent magnets(120) attached on the rotor core, a stator yoke(130) including a core magnetic pole(140) and forming concentric circle with the rotator core, and a coil(150) wound around a slot(155) between the core magnetic pole.

Description

COIL FOR MOTOR AND BRUSHLESS DC MOTOR USING THE SAME}

The present invention relates to a coil for a motor and a brushless DC motor using the same, and more particularly, to a motor coil including an aluminum and a brushless DC motor using the same.

Today, more than 3.5 billion motors are produced annually as a part of many household appliances. The motors can be broadly classified into DC motors, AC motors (induction, synchronous), and step motors. In addition, although it is widely manufactured from a small machine to a large machine, in the general industrial, home appliances, robots, OA equipment, FA equipment, automobiles, and the like, most of the motors are small machines (10 W or less).

In general, the motor is divided into iron cores, permanent magnets, and copper wires for electric circuits. More than 100 motors are used in automobiles. As demand for convenience facilities for drivers and passengers is increasing, the demand for electric and electronic devices is expected to increase. Increasing these devices will eventually increase the weight of the car, etc.

In general, the weight percentage of copper wire in transformers and motors ranges from as little as 30% to as much as 50% or more of their total weight. In addition, when the motor is disposed of, the copper wire is manually separated from the iron core, or the iron and copper are melted to separate the copper and the iron core, resulting in time or economic loss.

It is an object of the present invention to provide a motor coil and a brushless DC motor using the same, which can realize light weight and economy.

According to an embodiment of the present invention, in a coil for a motor wound on a stator or a rotor to generate magnetic flux when power is applied, the coil includes aluminum.

According to an embodiment of the present invention, the coil made of aluminum may have a quasi-crystal structure.

According to an embodiment of the present invention, the coil made of aluminum may include 0.5 to 5wt% of silicon.

Brushless DC motor according to an embodiment of the present invention comprises a rotor iron core, a plurality of permanent magnets attached to the rotor iron core, forming a concentric circle with the rotor iron core, between the stator yoke and the iron core magnetic pole comprising an iron core pole A coil wound in a slot of the coil, wherein the coil comprises aluminum.

The coil including aluminum according to an embodiment of the present invention may have a quasi-crystal structure.

According to an embodiment of the present invention, the aluminum constituting the coil may include 0.5 to 5wt% of silicon.

When the quasi-crystalline aluminum wire according to the embodiment of the present invention is used as a coil for a motor, economical and social effects such as energy consumption reduction due to weight reduction of an automobile or the like may occur.

In particular, when aluminum wire is used for winding of the motor, the separation work after melting the entire motor (including iron cores) is easier than that of copper because the difference in melting point between aluminum and iron is large, and it is inherent that iron has even without separate separation work. It has the advantage that it does not affect the characteristics of much.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art may easily implement the technical idea of the present invention. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents may be thorough and complete, and the technical spirit of the present invention may be sufficiently delivered to those skilled in the art.

In the drawings, each component may be exaggerated for clarity. The same reference numerals throughout the specification represent the same components.

Meanwhile, for simplicity of description, some embodiments to which the technical spirit of the present invention may be applied are described as examples, and descriptions of various modified embodiments are omitted. However, one of ordinary skill in the art may apply the inventive concept of the present invention to various cases based on the above description and the embodiments to be illustrated.

1 is a graph for explaining the manufacturing conditions of quasi-crystalline aluminum according to an embodiment of the present invention.

In Figure 1, the vertical axis is the mold temperature (° C) and the horizontal axis is the casting speed (mm / min). Quasi-crystalline aluminum wire can be produced by controlling the mold temperature and casting speed. Continuous casting process is performed on aluminum molten steel flowing out of the molten metal. The heating temperature of the mold is controlled to 30 ~ 50 ℃ higher than the liquidus temperature can maintain the molten aluminum liquid phase.

In the continuous casting process, it is possible to quench liquid aluminum molten steel. By such a quenching process, the liquid aluminum molten steel can be made of aluminum wire in an amorphous state, that is, quasi-crystalline aluminum wire, in which the atomic arrangement is disordered. In this quenching process, cooling water may be supplied at 0.3 to 0.4 l / min.

As shown in FIG. 1, pure aluminum (X) may form a semi-crystalline structure within the indicated mold temperature and casting speed range. On the other hand, in the case of aluminum (Y) to which 5 wt% of silicon (Si) is added (Y), a semi-crystalline structure can be formed within a range of the displayed mold temperature and casting speed. If the casting speed decreases within a predetermined temperature range, the rough surface increases without forming a semi-crystalline structure, and if the casting speed increases, the streaking increases without forming a semi-crystalline structure. Therefore, whether or not the aluminum wire is a semi-crystalline structure can be determined by the surface roughness and the file shape.

FIG. 2 is a photograph for comparing a stripe of a semi-crystalline aluminum wire A and a general aluminum wire B. FIG.

Referring to FIG. 2, when comparing the tritriation of the semi-crystalline aluminum wire (A) and the general aluminum wire (B), the general aluminum wire (B) is more streaked than the semi-crystalline aluminum wire (A) You can see that. Through the surface observation, it is possible to confirm the semicrystalline structure of the aluminum wire.

3A is a diagram showing the surface roughness of a semi-crystalline aluminum wire, and FIG. 3B is a diagram showing the surface roughness of a general aluminum wire. In Figures 3a and 3b, the vertical axis represents the roughness in micrometers (μm), the horizontal axis represents the distance in a constant section. 3A and 3B, since the surface roughness of the semi-crystalline aluminum wire A appears more uniformly with distance than the general aluminum wire, it can be confirmed that it is satisfactory. As mentioned in FIG. 1, since the surface roughness increases when the semicrystalline structure is not formed, the semicrystalline structure may be confirmed by observing the surface of the aluminum wire specimen.

4 is an enlarged photograph showing the surface macrostructure of the semicrystalline aluminum casting. It can be seen that the surface fringes are formed in the photo of the quasi-crystalline aluminum casting prepared and the surface corroded. Since the surface pattern has a directionality, the electrical conductivity of the semi-crystalline aluminum wire can be improved.

FIG. 5 is a graph showing a change in electrical resistivity with heat treatment time in the semi-crystalline aluminum ultrafine wire according to the embodiment of the present invention.

Referring to FIG. 5, a semi-crystalline aluminum casting material is processed, drawn into an 8 mm diameter, a stress relief heat treatment process is performed, and a change in specific resistance is measured. It can be seen that as the heat treatment time increases, the electrical resistivity decreases. Therefore, it is necessary to increase the electrical conductivity of the semi-crystalline aluminum microwire by increasing the heat treatment time. This is because the semi-crystalline aluminum wire has a smaller electrical conductivity than the copper wire.

6 is a graph showing a change in elongation according to a heat treatment temperature of a semi-crystalline aluminum ultrafine wire according to an embodiment of the present invention.

Referring to FIG. 6, when the aluminum to which 1 wt% silicon is added has a semicrystalline structure, it can be seen that the elongation increases when the heat treatment temperature is high. Therefore, it is possible to increase the heat treatment temperature so that the semi-crystalline aluminum ultrafine wire is suitable for use as a coil. That is, when the semi-crystalline aluminum wire is wound in the slot or the like, it is preferable that the elongation is large.

7 is a view schematically showing a brushless DC motor using a coil for a motor according to an embodiment of the present invention.

Referring to FIG. 7, the brushless DC motor 100 forms a concentric circle with the rotor iron core 110, the plurality of permanent magnets 120 attached to the rotor iron core 110, and the rotor iron core 110. A stator yoke 130 including an iron core pole 140 and a coil 150 wound around a slot 155 between the iron core pole 140.

The coil 150 is made of aluminum. The aluminum may have a semi-crystalline structure. Alternatively, the coil 150 made of aluminum may include 0.5 to 5 wt% of silicon. When the power is applied to the coil 150, magnetic flux is generated, and the rotor core 110 may thereby rotate. The motor 100 may be used in a vehicle to improve the weight and recyclability of the vehicle.

As shown in FIG. 7, in the plurality of permanent magnets 120, 12 poles of permanent magnets may be alternately arranged on the circumference of the rotor iron core 110. In addition, the slot 155 may be nine, and may be composed of a three-phase coil wound around nine slots 155. The power applied to the three-phase coil generates a synthetic magnetic flux, and a rotating magnetic field may be generated by the synthetic magnetic flux.

The case where the coil of the motor 100 is made of aluminum wire is compared with the case of copper wire. The specific gravity of aluminum is about 2.7, which is about 1/3 compared to the specific gravity of 7.9 of iron and 8.9 of copper (copper), and the conductivity is 60% of copper. As a result, 1.6 times the cross-sectional area is required to flow the same amount of current as copper, but since the specific gravity is 1/3 of copper, it is possible to flow twice the current with the same weight.

For this reason, 99% aluminum is employed in electricity transmission lines, especially high voltage transmission lines. In addition, aluminum is more difficult to oxidize than other metals, and aluminum can be easily melted and recycled because of its low melting point.

In addition, the energy required to make recycled aluminum base metals is solved at only 3% compared to the case of new aluminum nowadays, which is very economical because it can produce almost the same quality as new ones. It can be said. In particular, in the cans, recycling campaigns, such as collecting empty cans and recycling, are carried out all over the country, contributing to resource saving and power saving, and playing a major role in promoting global environmental protection and waste reduction. In addition, due to the efficient recycling of aluminum as described above, the manufacturing cost of the aluminum wire can be reduced in the near future.

It can be seen from the following equation that 1.6 times the cross-sectional area is required to flow the same amount of current through the aluminum wire. First, because the same amount of current flows can be regarded as the same resistance,

R _Al = R _Cu ---------- (1)

ρ _Al (1 / S _Al ) = ρ _Cu (1 / S _Cu ) ---------- (2)

In the formulas (1) and (2), the cross-sectional area of the _copper is S _Cu = 1, the length of the aluminum wire and the copper wire is 1, and eventually,

0.0282 (1 / S _Al ) = 20.0172 ---------- (3)

Equation (3) gives S _Al = 1.6.

When the weight of the aluminum wire is equal to the weight of the existing copper, the conductivity becomes (8.9 / 2.7) x 61 = 201 (%), and the current flows twice as much as the existing copper wire. In addition, since the temperature coefficients of aluminum and copper are almost the same, it can be said that the change in resistance value with the actual temperature rise of the motor is the same.

Copper (standard interlocking) and physical properties of aluminum Resistivity
(At 20 ℃)
(* 10-6 [Ωm]) Conductivity
(Based on 20 ℃) (%) Temperature coefficient
(20 ℃ standard) importance Melting point
(℃) The tensile strength
[MPa] Cu 0.0172 100 0.00393 8.9 1083 200 Al 0.0282 61.0 0.0039 2.7 660 80

On the other hand, the characteristics evaluation results of measuring the efficiency of the brushless DC motor (BLDC), DC motor (DC), AC motor (AC) made of a semi-crystalline aluminum wire according to an embodiment of the present invention are shown in Table 2.

Characterization of each motor when applying aluminum wire Item unit BLDC
(Copper wire) BLDC
(Al line) DC
(Copper wire) DC
(Al line) AC
(Copper wire) AC
(Al line) Efficiency % 70.5 67.1 85.3 87.1 68.1 61.3 Output W 183.1 181.7 491 345 190 169 No-load speed rpm 1828 1808 3174 3126 1770 1777 Efficiency @ Maximum Power % 70.5 67.1 Speed @ Maximum Power rpm 1781 1768 Current @ Maximum Output A 1.919 1.977 Torque @ max output kg.cm 10.01 10 Efficiency @ 21kgcm % 60.5 48.7 Speed @ 21kgcm rpm 2028 1578 Current @ 21 kgcm A 8.06 7.77 Efficiency @ 1400 rpm % 59.4 53.6 Torque @ 1400rpm kg.cm 13.25 11.66 Current @ 1400 rpm A 2.79 2.72

Noise measurement result of each motor Type Coil type Noise [dB] BLDC Copper wire 56.3 Aluminum wire 59.1 DC Copper wire 58.7 Aluminum wire 53.4 AC Copper wire 65.4 Aluminum wire 66.7

As a result of analyzing the characteristics of each motor, the case of applying a semi-crystalline aluminum wire to a brushless DC motor (BLDC) has the best characteristics compared to the case of winding a copper wire on the motor. Brushless DC motors show almost the same efficiency and output when winding copper wire and when applying semi-crystalline aluminum wire.

When the quasi-crystalline aluminum wire according to the embodiment of the present invention is used as a coil for a motor, economical and social effects such as weight reduction of automobiles, ease of recycling, and reduction of energy consumption by weight reduction may occur.

According to the embodiment of the present invention, through the process control of the aluminum wire, it is possible to manufacture and process the semi-crystalline aluminum wire, and the characteristics of elongation, strength, electrical conductivity or weldability through drawing, heat treatment can be improved.

1 is a graph for explaining the manufacturing conditions of quasi-crystalline aluminum according to an embodiment of the present invention.

FIG. 2 is a photograph for comparing a stripe of a semi-crystalline aluminum wire A and a general aluminum wire B. FIG.

3A is a diagram showing the surface roughness of a semi-crystalline aluminum wire, and FIG. 3B is a diagram showing the surface roughness of a general aluminum wire.

4 is a photograph showing surface structure of a semi-crystalline aluminum casting.

FIG. 5 is a graph showing a change in electrical resistivity with heat treatment time in the semi-crystalline aluminum ultrafine wire according to the embodiment of the present invention.

6 is a graph showing a change in elongation according to a heat treatment temperature of a semi-crystalline aluminum ultrafine wire according to an embodiment of the present invention.

7 is a view schematically showing a brushless DC motor using a coil for a motor according to an embodiment of the present invention.

Claims (6)

In the coil for the motor wound around the stator or the rotor to generate magnetic flux when the power is applied, The coil of a motor, characterized in that the coil comprises aluminum. The method according to claim 1, The aluminum coil has a semi-crystalline structure. The method according to claim 1, The aluminum is a coil for a motor containing 0.5 ~ 5wt% silicon. Rotor iron core; A plurality of permanent magnets attached to the rotor iron core; A stator yoke concentric with the rotor iron core and including an iron core pole; And Including a coil wound in a slot between the iron core poles, Brushless DC motor, characterized in that the coil comprises aluminum. The method according to claim 4, Brushless DC motor, characterized in that the aluminum has a semi-crystalline structure. The method according to claim 4, Brushless DC motor, characterized in that the aluminum comprises 0.5 ~ 5wt% silicon.

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