KR102472096B1 - DC Brush Motor - Google Patents

Abstract

The present invention relates to a DC brush motor, comprising: a cylindrical yoke; armature part; a plurality of magnets spaced apart from each other and disposed between the yoke and the armature unit; and a reduction unit disposed on at least one of an inner circumferential surface and an outer circumferential surface of the yoke to relieve saturation of magnetic flux density of the yoke. Accordingly, the magnetic flux density saturation of the yoke may be reduced by using the reducing unit.

Description

DC Brush Motor

The present invention relates to a DC brush motor.

DC brush motors (DC MOTORs) have strong rotational power, rotation characteristics are linearly proportional to applied voltage, output power is linearly proportional to input current, and output efficiency is good. And the price is also cheap.

More specifically, the torque is proportional to the flowed current according to the T-I characteristic (torque vs. current). Also, according to the T-N characteristic (torque vs. number of revolutions), the number of rotations is linearly inversely proportional to the torque.

Since these two characteristics interlock with each other, they form an important relationship, and what can be seen from these characteristics is that the current can be controlled to control the number of revolutions or torque to be constant. As such, DC brush motors are very easy to control.

The DC brush motor generates magnetic flux by a magnet, and a ferromagnetic metal body called a yoke may be disposed outside the magnet to form a magnetic path of the magnet.

At this time, a sufficient thickness of the yoke must be ensured so that the flow of magnetic flux is smooth and the magnet can be used efficiently. There is a problem of not securing the thickness of.

Particularly, the region where the polarity of the magnet is changed is a region where magnetic flux is concentrated, and magnetic flux density saturation occurs, thereby increasing leakage flux. Accordingly, there is a problem in that the efficiency of the magnet is also reduced.

In addition, when the thickness of the yoke is increased in order to solve this phenomenon, the weight and size of the DC brush motor increase, resulting in an increase in cost. Inventions related to this include Japanese Unexamined Utility Model Publication No. Hei 03-117358 (1991.12.04.), Japanese Unexamined Patent Publication No. 2010-148209 (2010.07.01.), Japanese Unexamined Patent Publication No. 2009-077590 (2009.04. 09.).

A technical problem to be achieved by the present invention is to solve the above problems, to provide a DC brush motor capable of mitigating the saturation of magnetic flux density occurring in one area of a yoke and reducing the size while maintaining performance accordingly.

The above object according to one embodiment of the present invention, a cylindrical yoke; armature part; a plurality of magnets spaced apart from each other and disposed between the yoke and the armature unit; and a reducing unit disposed on at least one of an inner circumferential surface and an outer circumferential surface of the yoke to relieve saturation of magnetic flux density of the yoke.

The reducing unit may be an inner reducing unit disposed on an inner circumferential surface of the yoke and disposed between the magnets, or an outer reducing unit disposed on an outer circumferential surface of the yoke to correspond to a separation space formed between the magnets.

Here, the inner reducing portion may be thicker toward the center.

In addition, a thickness of each of the inner reduced portion and the outer reduced portion based on the radial direction of the yoke may be 10% or more of the thickness of the yoke.

That is, the thickness of each of the inner reduced portion and the outer reduced portion based on the radial direction of the yoke may be 10% to 230% of the thickness of the yoke.

In addition, a width of the inner reducing portion based on the circumferential direction of the yoke may be 5% or more of an inner circumference of the yoke.

In addition, based on the circumferential direction of the yoke, the width of the outer reducing portion may be 5% or more of the outer circumference of the yoke.

In addition, when the inner reducing part and the outer reducing part are disposed with the yoke interposed therebetween, the sum of the thickness of the inner reducing part and the outer reducing part may be 10% or more of the thickness of the yoke.

Also, based on the circumferential direction of the yoke, a width of the inner reduced portion may be smaller than a width of the outer reduced portion.

And, the reduction unit may be integrally formed with the yoke.

In addition, the magnet may be disposed such that N poles and S poles are alternately spaced apart from each other.

In the DC brush motor according to an embodiment of the present invention having the configuration described above, the magnetic flux density saturation of the yoke can be reduced by using the reducing unit.

Accordingly, the size of the DC brush motor can be reduced while maintaining the same performance.

1 is a diagram showing a DC brush motor according to an embodiment of the present invention;
2 is a diagram showing magnetic flux density saturation of a DC brush motor without a reducing unit;
3 is a diagram showing magnetic flux density saturation of a DC brush motor according to an embodiment of the present invention;
4 is a diagram showing a comparison of magnetic flux density saturation of a DC brush motor without a reducing unit and a DC brush motor according to an embodiment of the present invention;
5 is a diagram showing a change in performance according to a thickness of a reducing part of a DC brush motor according to an embodiment of the present invention;
6 is a diagram comparing leakage flux of a DC brush motor without a reducing unit and a DC brush motor according to an embodiment of the present invention;
7 to 9 are views showing magnetic flux density saturation of a DC brush motor according to another embodiment of the present invention.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as second and first may be used to describe various components, but the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a second element may be termed a first element, and similarly, a first element may be termed a second element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

In the description of the embodiment, in the case where one component is described as being formed “on or under” another component, the upper (above) or lower (below) (on or under) includes both those formed by direct contact between two components or by indirectly placing one or more other components between the two components. In addition, when expressed as 'on or under', it may include the meaning of not only the upward direction but also the downward direction based on one component.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, it should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, but the same or corresponding components regardless of reference numerals are given the same reference numerals, and overlapping descriptions thereof will be omitted.

1 to 9, a DC brush motor 1 according to an embodiment of the present invention includes a shaft 100, an armature unit 200 disposed on an outer circumferential surface of the shaft 100, a yoke 300, It may include a magnet 400 and a reduction unit.

Here, the reducing unit may be disposed on at least one of an inner circumferential surface and an outer circumferential surface of the yoke 300 . Accordingly, in describing the reduction unit of the DC brush motor 1, the reduction unit located on the inner circumferential surface of the yoke 300 is classified as an inner reduction unit 500 according to the arrangement position of the reduction unit, and the yoke 300 The reduction part located on the outer circumferential surface of is divided into an outer reduction part (500a) and is clarified.

The shaft 100 may be disposed at the center of the armature unit 200 .

The armature unit 200 may include an armature 210 and a conductor 220 . Also, when current is applied to the conductor 220 , the armature 210 may rotate with respect to the shaft 100 .

The yoke 300 may be formed in a cylindrical shape and may be spaced apart from the outer circumferential surface of the armature unit 200 . Here, the yoke 300 may be formed with a predetermined yoke thickness t1. And, the yoke 300 may be formed of a ferromagnetic metal body.

A plurality of magnets 400 may be disposed spaced apart from each other between the outer circumferential surface of the armature unit 200 and the inner circumferential surface of the yoke 300 . Here, the magnet 400 may be formed in an arc shape and may be fixedly disposed on the inner circumferential surface of the yoke 300 . Also, in the magnet 400, N poles and S poles may be alternately disposed. Accordingly, magnetic flux may be generated.

The inner reducing unit 500 may be disposed between the magnets 400 in which N poles and S poles are alternately disposed.

As shown in FIG. 2 , when the reducing unit is not disposed, it can be seen that magnetic flux density saturation occurs in one region A of the yoke 300 at a position where the magnet 400 is not disposed, and leakage flux increases. Accordingly, the efficiency of the magnet 400 is reduced.

As shown in (a) of FIG. 3 , the inner reducing portion 500 is disposed between the magnets 400 and may be disposed on the inner circumferential surface of the yoke 300 . Accordingly, as shown in (b) of FIG. 3 , the inner reducing unit 500 may reduce magnetic flux density saturation in one area of the yoke 300 .

As shown in (a) of FIG. 4, it can be confirmed that magnetic flux density saturation occurs when the reducing unit 500 is not disposed, and as shown in (b) of FIG. 4, the inner reducing unit 500 In the case of the DC brush motor 1 in which is disposed, it can be seen that the saturation of the magnetic flux density of the yoke 300 is alleviated.

Here, the inner reduced portion 500 may be formed with a preset reduced portion thickness t2 based on the radial direction r. Also, the inner reducing unit 500 may be formed of a metal piece made of a ferromagnetic material. For example, the inner reducing unit 500 may be formed of a material having Br (residual magnetic flux density) of 1T or more.

The reduction effect of the magnetic flux density saturation of the yoke 300 may occur when the thickness t2 of the inner reduction unit 500 is 10% or more compared to the yoke thickness t1.

Referring to FIG. 5, the yoke 300 when the reduced thickness t2 of the inner reduced portion 500 is 10% to 230% compared to the yoke thickness t1 of the magnet 400 so that the Back-EMF is maximized. The effect of reducing the saturation of the magnetic flux density can occur.

In addition, the width W1 of the inner reducing portion 500 in the circumferential direction should be 5% or more of the inner circumference of the yoke 300 so that the magnetic flux density saturation of the yoke 300 is reduced.

Here, the width W1 of the inner reduced portion 500 in the circumferential direction may be an average width from one edge to the other edge in the circumferential direction. However, considering the condition that the inner diameter of the yoke 300 must be 5% or more and the manufacturing cost condition, the width W1 in the circumferential direction of the inner reduced portion 500 is in contact with the inner circumferential surface of the yoke 300. It may be the width of the outer circumferential surface of the inner reducing part 500.

6(a) is a diagram showing a DC brush motor in which the reduction unit is not disposed under predetermined examination conditions, and FIG. 6(b) shows the DC brush motor 1 in which the inner reduction unit 500 is disposed. It is a drawing that represents

Here, as the above review conditions, the yoke thickness (t1) is 1.8T, the reduced thickness (t2) of the inner reduced portion 500 is 3.0T, and the thickness (t3) of the magnet 400 is 6.2T.

As a result, as shown in FIG. 6 , it can be seen that the amount of leakage flux of the DC brush motor 1 in which the inner reducing unit 500 is disposed is reduced by 22%.

At this time, the inner reducing portion 500 may be inserted and installed as a separate metal piece, or may be integrally formed with the yoke 300.

When the inner reducing portion 500 is integrally formed with the yoke 300 on the inner surface of the yoke 300, the assemblability of the magnet 400 can be improved. That is, as the reducing portion 500 is integrally formed with the yoke 300, when assembling the magnet 400, the magnet 400 is guided by the inner reducing portion 500, so the magnet for the yoke 300 ( 400) can be improved.

On the other hand, the inner reducing portion 500, as shown in (a) of FIG. 7, may be formed in a shape in which the thickness increases toward the center with respect to the circumferential direction, as shown in (b) of FIG. As such, the effect of reducing the magnetic flux density saturation occurs. At this time, the reduction part thickness t2 of the inner reducing part 500 for reducing the magnetic flux density saturation may be regarded as an average thickness of the entire thickness.

In the present invention, the reducing unit 500 has a convex shape in which the thickness increases toward the center with respect to the circumferential direction as an example, but is not necessarily limited thereto, and is formed in a concave shape in which the thickness decreases toward the center of the reducing unit. It could be.

The convex shape may further reduce the saturation of magnetic flux density of the yoke 300 at the center side in the circumferential direction of the inner reducing part 500 . In addition, the concave shape increases the thickness of both edges of the inner reducing portion 500 in the circumferential direction, thereby further improving the assembly property of the magnet 400 .

On the other hand, as shown in Figure 8, the outer reduction portion (500a) may be disposed on the outer surface of the yoke (300). Accordingly, a separation space (S) formed between the outer reducing portion (500a) disposed on the outer circumferential surface of the yoke 300 and the magnet 400 may be disposed with the yoke 300 therebetween.

Here, the outer reduced portion 500a may be formed with a preset reduced portion thickness t4 based on the radial direction r. In addition, the outer reducing portion 500a may be formed of a metal piece made of a ferromagnetic material. Here, the outer reducing unit 500a may be formed of a material having a Br (residual magnetic flux density) of 1T or more. In addition, the outer reducing portion 500a may be integrally formed with the yoke 300 to reduce costs through simplification of the manufacturing process.

The reduction part thickness t4 of the outer reduction part 500a should be 10% or more compared to the yoke thickness t1 so that the magnetic flux density saturation of the yoke 300 is reduced. For example, when the thickness t4 of the external reduction part 500a is 10% to 230% compared to the yoke thickness t1 of the magnet 400 so that the Back-EMF is maximized, the magnetic flux density saturation of the yoke 300 is A diminishing effect may occur.

Also, the width W2 of the outer reducing portion 500a in the circumferential direction should be 5% or more of the outer circumference of the yoke 300 so that the magnetic flux density saturation of the yoke 300 is reduced.

Here, the width W2 of the outer reduced portion 500a in the circumferential direction may be an average width from one edge to the other edge in the circumferential direction. However, considering the condition that the outer circumference of the yoke 300 must be 5% or more and the manufacturing cost condition, the width W2 in the circumferential direction of the outer reduced portion 500a is in contact with the outer circumferential surface of the yoke 300 It may be the width of the inner circumferential surface of the outer reducing portion (500a).

In addition, as shown in FIG. 9 , the inner reducing part 500 and the outer reducing part 500a may be disposed to face each other with the yoke 300 interposed therebetween. Here, the inner reducing part 500, as described above, is disposed on the inner circumferential surface of the yoke 300, but can be disposed in the spaced space (S) between the magnets 400 in which N poles and S poles are alternately disposed with each other. have.

The sum of the thickness of the reduction part t2 of the inner reducing part 500 and the thickness of the reducing part t4 of the outer reducing part 500a must be 10% or more compared to the yoke thickness t1 to reduce the magnetic flux density saturation of the yoke 300 effect can occur. For example, the sum of the reduced thickness t2 of the inner reduced portion 500 and the reduced thickness t4 of the outer reduced portion 500a is greater than the yoke thickness t1 of the magnet 400 so that the Back-EMF is maximized. When it is 10% to 230%, an effect of reducing saturation of the magnetic flux density of the yoke 300 may occur.

At this time, the width W2 of the outer reduced portion 500a in the circumferential direction may be wider than the width W2 of the inner reduced portion 500a in the circumferential direction.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art can variously modify and modify the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be changed. And, it should be construed that the differences related to these modifications and changes are included in the scope of the present invention, which is defined in the appended claims.

1: DC brush motor
100: shaft 200: armature part
300: York 400: Magnet
500: inner reducing unit 500a: outer reducing unit

Claims (11)

shaft;
an armature provided as an electromagnetic unit coupled to the shaft;
York;
a plurality of magnets spaced apart from each other in a circumferential direction between the yoke and the armature; and
A reducing portion disposed on at least one of an inner circumferential surface or an outer circumferential surface of the yoke to relieve saturation of the magnetic flux density of the yoke;
The reducing unit is disposed on the inner circumferential surface of the yoke and is disposed on the outer circumferential surface of the yoke to correspond to the inner reducing unit disposed between the magnets or the separation space formed between the magnets,
When the inner reducing portion and the outer reducing portion are disposed with the yoke interposed therebetween, the sum of the thickness of the inner reducing portion and the outer reducing portion is 10% or more of the thickness of the yoke. delete According to claim 1,
The inner reduction part becomes thicker toward the center of the motor. According to claim 1,
The thickness of each of the inner reducing portion and the outer reducing portion based on the radial direction of the yoke is 10% or more of the thickness of the yoke. According to claim 4,
The thickness of each of the inner reducing portion and the outer reducing portion based on the radial direction of the yoke is 10% to 230% of the thickness of the yoke motor. According to claim 1,
Based on the circumferential direction of the yoke, the width of the inner reducing portion is 5% or more of the inner circumference of the yoke. According to claim 1,
Based on the circumferential direction of the yoke, the width of the outer reducing portion is 5% or more of the outer circumference of the yoke. delete According to claim 1,
A motor in which a width of the inner reducing portion is smaller than a width of the outer reducing portion based on the circumferential direction of the yoke. According to claim 1,
The reduction unit motor integrally formed with the yoke. delete

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