KR20200102590A - Outer-rotor type bldc motor - Google Patents

Abstract

The present invention relates to an outer-rotor type BLDC motor which comprises: a fixed shaft serving as a central axis; a stator coupled to and fixed to the fixed shaft; a rotor coupled to be rotatable on an outer peripheral surface of the stator; and a permanent magnet coupled to an inner circumferential surface of the rotor. The stator comprises: a core in which an outer wall in contact with the permanent magnet and an inner wall in contact with the fixed shaft are spaced apart from each other to form a hollow; an insulating member coupled to the core; and a coil wound around the insulating member. The core is partially cut and formed to be unfolded in a straight shape. Therefore, the present invention has an effect of reducing vibration and noise of the motor and improving output performance.

Description

Outer electric type BLDC motor {OUTER-ROTOR TYPE BLDC MOTOR}

The present invention relates to an abduction type BLDC motor, and more particularly, to an abduction type BLDC motor having a developable core.

In general, a motor is a device that converts electrical energy into mechanical energy to obtain rotational power, and is widely used not only in home electronics but also in industrial equipment, and is largely classified into a DC motor and an AC motor. In a DC motor, a motor with a brush attached to it flows current through the coil and rectifies it at the same time by contacting the commutator with the brush, but there is a disadvantage that the brush is worn according to the use of the motor. To overcome this drawback, a brushless BLDC motor is used.

BLDC motors have been widely used in recent years because they have a large torque and excellent controllability and can achieve rapidity. BLDC motors are divided into inner-rotor type and outer-rotor type according to the position of the rotor. Since the outer diameter of the rotor is smaller than that of the abduction type, the moment of inertia can be reduced, so it is suitable for applications requiring quick response.However, high-speed rotation is not possible due to the limitations of the mechanical strength of the permanent magnet and the adhesive strength with the rotor. There is a difficult drawback. On the other hand, in the case of the abduction type, the outer diameter of the rotor is large and the moment of inertia is large, but there is an advantage that is suitable for high speed use because a permanent magnet can be attached inside the rotor.

In the abduction type BLDC motor, as shown in FIG. 1, a permanent magnet 300 is attached to an inner circumferential surface of the rotor 200 and a stator 10 is coupled therein. In the conventional abduction type BLDC motor, the core 11 formed on the stator 10 has an inner wall formed at a central portion coupled to the fixed shaft, and a plurality of teeth 11 protrude radially from the inner wall. In addition, an outer wall protrudes from the end of the tooth 13 in the circumferential direction to come into contact with the permanent magnet 300. Since a slot is formed between the teeth 11, the coil 130 is wound inside the slot. At this time, the performance of the motor depends on the amount of the coil 130 wound.

However, since the plurality of teeth 11 are located adjacent to each other, the area of the slot is narrow and it is not easy to wind the coil 130. And, since it is located in the space between the teeth 11 to the nozzle for winding the coil 130 together with the coil 130, there is a limit to securing an area for sufficiently winding the coil 130, so that the dot ratio is reduced. There is a problem.

In addition, since the outer wall of the core 11 in contact with the permanent magnet 300 is not integrally formed, a cogging torque is generated. Cogging torque is a torque generated by magnetic force between a slot and a permanent magnet, and when cogging torque occurs, noise and vibration are induced, and output performance of the motor is deteriorated.

The present invention has been conceived to solve the conventional problems as described above, and it is an object of the present invention to provide an abduction type BLDC motor capable of improving a dot ratio for winding a coil on a stator and preventing cogging torque. To do.

The present invention for achieving the above object, the fixed shaft that becomes the central axis; A stator coupled to and fixed to the fixed shaft; A rotor coupled to be rotatable on an outer peripheral surface of the stator; And a permanent magnet coupled to an inner circumferential surface of the rotor, wherein the stator comprises: a core in which an outer wall in contact with the permanent magnet and an inner wall in contact with the fixed shaft are spaced apart from each other to form a hollow; An insulating member coupled to the core; And a coil wound around the insulating member, wherein the core is partially cut to be unfolded in a straight shape.

Here, the core includes: a first cutout formed in a radial direction such that a part of the outer wall is cut; A second cutout formed in a radial direction such that the inner wall is cut; And a tooth having one end in contact with the outer wall and the other end in contact with the inner wall to which the insulating member is coupled.

In addition, the first cut-out portion is formed so that the inner circumferential surface of the outer wall is cut, and the second cut-out portion is formed so that the inner wall is cut so that a hollow between the outer wall and the inner wall is opened.

In addition, the second cutout and the first cutout may be formed such that irregularities are formed on a cut surface of the inner wall.

According to the present invention, by forming a stator composed of an expandable core, the space in which the coil is wound is increased, and the dot ratio of the coil is improved, thereby improving the output performance of the motor.

In addition, the outer wall of the core in contact with the permanent magnet is integrally formed so that there is no open space on the outer circumference of the core, thereby preventing the generation of cogging torque, thereby reducing noise and vibration of the motor.

And, by improving the dot ratio of the coil, there is an effect of reducing the size of the motor having the same output performance.

In addition, by expanding the core so that it can be wound on the inner circumferential side, workability for winding the coil is improved, and productivity is improved.

1 is a cross-sectional view of a conventional abduction type BLDC motor.
2 is a perspective view of an abduction type BLDC motor according to the present invention.
Figure 3 is an exploded perspective view of Figure 2;
4 is a cross-sectional view taken along line IV-IV' of FIG. 3;
Figure 5 is a cross-sectional view of the core of Figure 3;
Figure 6 is an exploded view of the core of Figure 3;
Figure 7 is an assembly view of the core and the insulating member of Figure 3;
8 is an exploded view of the stator of FIG. 3
9 is a cross-sectional view taken along line IX-IX' of FIG. 2;

Hereinafter, an abduction type BLDC motor according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 to 9 show an abduction type BLDC motor according to an embodiment, and FIG. 2 is a perspective view of an abduction type BLDC motor according to the present invention, FIG. 3 is an exploded perspective view of FIG. 2, and FIG. 4 is It is a cross-sectional view taken along line IV-IV' of. 5 is a cross-sectional view of the core of FIG. 3, FIG. 6 is an exploded view of the core of FIG. 3, and FIG. 7 is an assembly view of the core of FIG. 3 and an insulating member. In addition, FIG. 8 is an exploded view of the stator of FIG. 3, and FIG. 9 is a cross-sectional view taken along line IX-IX′ of FIG. 2.

As shown in these drawings, the abduction type BLDC motor (hereinafter referred to as'motor') according to an embodiment of the present invention includes a stator 100, a rotor 200, a permanent magnet 300, and a fixed shaft. It consists of 400.

The fixed shaft 400 is a central axis of the motor, and the stator 100 and the rotor 200 are coupled. After the stator 100 is coupled to the fixed shaft 400, the rotor 200 is coupled to contact the outer circumferential surface of the stator 100.

The rotor 200 is formed as a cylindrical column, and is coupled to the fixed shaft 400 so as to contact the outer circumferential surface of the stator 100. A magnetized permanent magnet 300 is coupled to the inner circumferential surface of the rotor 200, and when a current is applied to the coil 130 wound around the stator 100 to be described later, the permanent magnet 300 and the coil 130 As the rotational force is generated by the interaction, the rotor 200 rotates.

The stator 100 is fixedly coupled to the fixed shaft 400 and is composed of a core 110, an insulating member 120, and a coil 130.

The core 110 is formed of an outer wall 114 in contact with the permanent magnet 300 coupled to the rotor 200 and an inner wall 115 in contact with the fixed shaft 400. The outer wall 114 and the inner wall 115 are formed to be spaced apart from each other, thereby forming a hollow. A plurality of teeth 113 for partitioning the space are radially formed in the hollow.

The tooth 113 has one end fixed to the outer wall 114 and the other end fixed to the inner wall 115, and an insulating member 120 for insulating the core 110 and the coil 130 is coupled. On the outer circumferential surface of the insulating member 120 coupled to the teeth 113, the coil 130 is wound to fill the hollow space formed between the adjacent teeth 113.

The core 110 of the present invention has a first cutout 111 for cutting a part of the outer wall 114 and a second cutout 112 for cutting the inner wall 115 so that it can be deployed in a straight shape do.

As shown in Figure 5, the first cutout 111 is not cut in the outer peripheral surface of the outer wall 114 in contact with the permanent magnet 300, the length shorter than the width of the outer wall 114 in the inner peripheral surface of the outer wall 114 It is formed to be cut into. In addition, the second cutout 112 is formed such that the inner wall 115 is cut open so that the hollow space divided by the teeth 113, the outer wall 114 and the inner wall 115 is opened.

By forming the first cutout 111 and the second cutout 112 as described above, the core 110 of the present invention can be deployed in a straight shape, as shown in FIG. 6. The developed core 110 is connected by the outer circumferential surface of the outer wall 114 and is deployed while the inner wall 115 is separated.

At this time, the cut surfaces of the first cutout 111 and the second cutout 112 are formed to have irregularities. When irregularities are formed on the cut surfaces of the first cutout 111 and the second cutout 112, when the core 110 is combined in a circular shape, the irregularities can be matched to each other, making it easy to work. There is an effect that the cut surface can be combined more stably.

In the operation for winding the coil 130 on the stator 100 as described above, first, the core 110 must be deployed to form a straight shape. Thereafter, after coupling the insulating member 120 to the tooth 113 and winding the coil 130, the core 110 so that the irregularities of the first cutout 111 and the second cutout 112 are well engaged with each other. Roll back into a circle.

At this time, the coil 130 may be wound as far as possible within an allowable range to fill the hollow space formed between the teeth 113. Even if the coil 130 is wound in a rather large amount, when the core 110 is rolled in a circular shape, the coil 130 is pressed against each other by the outer wall 114 and the inner wall 115 and is coupled to a high density.

And, the stator 100 rolled into a circle is coupled to the rotor 200 to which the fixed shaft 400 and the permanent magnet 300 are combined.

Conventionally, when the coil 130 is wound on the outer circumferential side of the core 110, when a large amount of the coil 113 is wound, the coil 113 is separated from the core 110. However, the core 110 of the present invention prevents the separation of the coil 130 by allowing the coil 130 to be wound on the inner circumferential side of the core 110 and not having an open space on the outer wall 114 and the inner wall 115. Can be prevented.

In this way, after opening the hollow space by cutting the inner wall 115 of the core 110, there is an effect that the operation of winding the coil 130 can be easily performed by allowing the coil 130 to be wound. In addition, even if a rather large amount of the coil 130 is wound, the dot ratio of the coil 130 can be improved by closing the hollow space in which the coil 130 is wound by the outer wall 114 and the inner wall 115, There is an effect that can improve the output performance of the motor.

In addition, as it is possible to improve the output performance of the motor by improving the dot ratio of the coil 130 to the motor of the same size, it is possible to implement a motor having the same output performance in a small size.

In addition, the outer wall 114 in contact with the permanent magnet 300 is integrally formed so that there is no open space on the outer circumferential surface of the stator 100, thereby preventing the occurrence of cogging torque. By preventing the occurrence of cogging torque, there is an effect of improving performance by reducing noise and vibration of the motor.

Since the above has been described only with respect to some of the preferred embodiments that can be implemented by the present invention, the scope of the present invention, as well known, should not be construed as being limited to the above-described embodiment, It will be said that both the technical idea of the invention and the technical idea that accompanies the fundamental are included in the scope of the present invention.

100: stator 110: core
111: first incision 112: second incision
113: tooth 114: outer wall
115: inner wall 120: insulating member
130: coil 200: rotor
300: permanent magnet 400: fixed shaft

Claims (5)

A fixed shaft 400 serving as a central axis;
A stator 100 coupled to and fixed to the fixed shaft 400;
A rotor 200 coupled to be rotatable on an outer peripheral surface of the stator 100; And
A permanent magnet 300 coupled to the inner circumferential surface of the rotor 200;
Including,
The stator 100,
A core 110 in which the outer wall 114 in contact with the permanent magnet 300 and the inner wall 115 in contact with the fixed shaft 400 are spaced apart from each other to form a hollow;
An insulating member 120 coupled to the core 110; And
A coil 130 wound around the insulating member 120;
Including,
The core 110 is an abduction type BLDC motor, characterized in that formed so as to be partially cut and unfolded in a straight line.
The method according to claim 1,
The core 110,
A first cutout 111 formed in a radial direction so that a part of the outer wall 114 is cut;
A second cutout 112 formed in a radial direction so that the inner wall 115 is cut; And
A tooth 113 having one end in contact with the outer wall 114 and the other end in contact with the inner wall 115 to which the insulating member 120 is coupled;
Abduction type BLDC motor comprising a.
The method according to claim 2,
The first cutout 111 is formed so that the inner circumferential surface of the outer wall 114 is cut,
The second cutout 112 is an abduction type BLDC motor, characterized in that the inner wall 115 is cut open so that the hollow between the outer wall 114 and the inner wall 115 is opened.
The method of claim 3,
The second incision 112,
Abduction type BLDC motor, characterized in that formed so as to form irregularities on the cut surface of the inner wall (115).
The method of claim 4,
The first cutout 111,
Abduction type BLDC motor, characterized in that formed so as to form irregularities on the cut surface of the outer wall (114).

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