KR20010057863A - A brushless motor of single phase - Google Patents

Abstract

PURPOSE: A single-phase commutatorless motor is provided to easily remove a non-maneuver point, and enhance manufacturing efficiency and productivity by cutting a part of an iron piece of a salient pole side and thus making thickness on the salient pole being asymmetric. CONSTITUTION: A coil(40) is wound on an arm(31). A salient pole(32) is formed on an end of the arm(31). The side of the salient pole(32) is structured to be asymmetric by cutting a part of an iron piece and removing the same. The core(30) is formed by integrally bonding a plurality of iron pieces. Each of the iron pieces has the salient pole(32) on the end of the arm(31). At this time, a part of an iron piece among the iron pieces is cut and becomes asymmetric in thickness to other side of a corresponding salient pole(32). An air gap between the core(32) and a magnet is constantly maintained. A corresponding surface of the salient pole(32) facing the magnet becomes symmetric about a center of a pole, thereby achieving smooth and stable magnetic flux. When the iron piece on the side forming the salient pole(32) is cut, at least one iron piece is preserved to form a stable magnetic path and cut portions are freely adjustable.

Description

A brushless motor of single phase

According to the present invention, the thickness of the protrusions is asymmetrical in the state where the protrusions facing the magnets of the core in which a plurality of iron pieces are stacked are kept uniformly spaced with the magnets, so that the starting point can be more easily removed. It relates to a commutator electric motor.

In general, there are many types of spindle motors used for driving a disk or a fan in small precision devices such as HDD (hard disk driver), FDD (floppy disk driver), cooling fan, and the like.

Among them, a cooling fan for the purpose of simple driving, which does not require precise control, is mostly adopted a non-commutator motor that requires inexpensive manufacturing.

Most of these non-rectifier motors have a radial three-phase driving method in which a magnet is provided in the radial direction of the core. However, in recent years, a single-phase driving method has been developed in accordance with a trend to simplify the configuration and improve economic efficiency. Or it is gradually increasing in the case of applying in two phases.

However, there is the most fatal flaw that a starting point occurs when the driving method is used as a single phase.

Fig. 1 shows a non-commutator electric motor applied to such a conventional cooling fan, which has a frame 1 of a flat plate at the bottom thereof, and a substrate 2 is attached to the frame 1 at the top thereof. In the center of (1), the tubular holder 1a which protrudes upward is integrally provided.

And the outer circumferential surface of the holder (1a) is to be coupled to the core 3 laminated a plurality of iron pieces.

The coil 4 is wound around the core 3, and the shaft 5 is rotatably inserted into the inner diameter of the holder 1a on which the core 3 is seated on the outer circumferential surface thereof. 6) are integrally combined.

The hub 6 has a cap shape extending downward from the outer circumferential end, and the magnet 6a is disposed on the inner circumferential surface of the downwardly extending end so as to face the end of the core 3 so as to have a uniform air gap with each other. Is attached.

The electric motor of the above-described configuration generates a driving force by an electromagnetic force generated by the interaction between the core 3 and the magnet 6a by the current flowing through the coil 4, and the hub 6 by the driving force at this time. Will rotate.

On the other hand, when the coil 4 wound on the core 3 is formed in a single phase in the configuration of the electric motor as described above, the coil torque is generated in the coil 4 in the shape of a dashed line as shown in FIG. 2.

This coil torque is always in a zero state at a constant angle as shown, so that it is impossible to start.

The position at which the electric motor cannot be started is called a fire starting point, and cogging torque as indicated by hidden lines in the drawing is required to remove this starting point.

On the other hand, the cogging torque is a torque generated between the end of the core 3 facing each other and the magnet 6a, so that the cogging torque is generated as shown, so that the motor can be smoothly driven by the combined torque indicated by the solid line. Will be.

However, as shown in FIG. 3, if the protrusion 3b formed at the end of the arm 3a is formed in a symmetrical structure on both sides while forming a uniform gap with the magnet 6a, the pole center and the magnet in the protrusion 3b are formed. Since the center is in a state of coincidence, the pole center of the magnet 6a is about to coincide with the magnetic center of the pole 3b, so that the pole pole 3b always operates only with one polarity of the magnet 6a. .

Thus, if the protrusion 3b of the core 3 acts only with one polarity of the magnet 6a, the protrusion 6b and the magnet 6a only pull or push radially from each other, so that the hub 6 Will not be driven at all while

Therefore, a method of improving the structure of the core 3 to the shape as shown in Figs. 4 and 5 has been proposed in order to eliminate the starting point of the coil torque is zero.

However, as in the structures described above, the surface facing the magnet 6a of the protrusion 3b is asymmetrical with respect to the pole center of the protrusion 3b, or the asymmetry of the gap between the protrusion 3b and the magnet 6a is asymmetric. To be formed, since very precise workability for determining the asymmetry amount is required, there is a problem in that production efficiency and productivity are lowered.

The present invention is to compensate for the above problems, the present invention for this purpose is to cut a part of the iron piece on the pole side so that the thickness at the pole is asymmetrical, so that the main point can be more easily removed.

In addition, the present invention can easily form the required cogging force simply by cutting one end of the iron piece forming the core, and thus has another object to improve the manufacturability and productivity.

1 is a side cross-sectional view showing a conventional general single-phase rectifier motor;

2 is an ideal torque waveform diagram in a single phase non-commutator motor;

3 is a cross-sectional view taken along the line a-a of FIG. 1;

Fig. 4 is a plan sectional view showing an embodiment in which the length of the protrusions facing the magnets of the conventional core is asymmetric;

5 is a plan sectional view of the conventional core due to the asymmetry of the gap between the poles opposed to the magnet of the core,

6 is a perspective view showing a main portion configuration according to the present invention,

7 is an application state of the core according to the present invention,

8 is an operational state diagram according to the present invention.

<Description of the symbols for the main parts of the drawings>

30: core 32: salient pole

40: coil

In order to achieve the above object, the present invention provides a single phase non-commutator motor in which a plurality of iron pieces of a flat plate are stacked so that magnets are provided to face each other with an outer end of the core seated on the outer circumferential surface of the holder.

One end of the salient pole facing the magnet of the core is characterized in that the thickness is reduced by cutting a portion of the iron piece is removed.

When described in detail with reference to the accompanying drawings a preferred embodiment of the present invention.

Fig. 6 is an exemplary view showing a core of an electric motor according to the present invention. The present invention is a configuration in which the core 30 in a single phase drive structure is improved, particularly in a radial type electric motor.

In other words, the core 30 has a coil 40 wound around the arm 31, and a protrusion 32 is formed at the end of the arm 31, and one side of the protrusion 32 is cut off and a part of the iron piece is removed. By doing so, the thickness of the protrusion 32 is to be formed in an asymmetrical structure.

That is, the core 30 is a configuration in which a plurality of iron pieces having a shape in which the protrusions 32 are formed at the ends of the arms 31 which are radially formed as described above are integrally coupled by a plurality of joints. The iron piece on one side of the iron pieces forming a part is to be cut so that the other side and the thickness of the protrusion 32 corresponding thereto are provided in asymmetrical shape.

In this case, as shown in FIG. 7, the gap between the core 32 and the magnet 61 is always kept constant, and the corresponding surface of the protrusion 32 opposite to the magnet 61 is symmetrical at the center of the magnetic pole, so that the magnetic flux is smooth. Keep the movement stable.

On the other hand, as described above when cutting the iron piece of one side constituting the pole 32, the portion to be cut while maintaining at least one iron piece that is not cut at least to form a stable ruler with the magnet 61 is freely adjustable.

That is, the present invention is to obtain a cogging torque for removing the starting point bar bar may be cut in multiple stages to obtain the ideal cogging torque, may cut only the iron piece of the upper side or the lower end side, upper and lower side iron piece It can also be cut at the same time so that some are removed.

When the core 32 is formed according to the above-described configuration, the cross-sectional area of the protrusion 32 which faces the magnet 61 forms an asymmetric structure.

Therefore, the other side of cutting the iron piece is formed relatively thin compared to one side of the core 32 is not cut the iron piece, so the deviation between the opposing surface occurs in the action force of the protrusion 32 and the magnet 61.

In other words, the magnetic center of each core 32 of the core 30 is formed by moving in the direction not cutting the iron piece from the pole center, so that the pole center of the magnet 61 tries to coincide with the magnetic center of the protrusion 32. Due to the characteristics, the magnet 61 is rotated at a predetermined angle to obtain a state as shown in FIG. 8.

Therefore, when the current is supplied to the coil 40 wound on the core 30, the magnet 61 is attached because the force to push or pull the magnet 61 in the rotational direction is generated between the protrusion 32 and the magnet 61. It is possible to continuously rotate the hub 60.

In addition, even if the current is interrupted, the magnet 61 is to act to coincide with the magnetic center of the pole 32 again, so that the pole 32 is returned to the state as shown in FIG.

As described above, the configuration in which the gap between the protrusions and the magnets are formed non-uniformly or asymmetrically between the opposing areas is very difficult to accurately set, whereas the present invention only needs to cut a part of the iron piece of the one side constituting the protrusion 32. It is very easy to manufacture.

In addition, cogging force adjustment is very easy because only the cutting size of the iron piece and the selection of the iron piece to be cut are necessary for generating the cogging force.

Therefore, the present invention simply removes a part of the iron pieces forming one side of the salient pole 32, thereby making it easy to remove the starting point by a configuration that makes the thickness of the salient pole 32 asymmetric.

In addition, the present invention is very easy to adjust for generating the optimum cogging force because the cogging force is changed according to the amount of iron strips removed.

In particular, the present invention provides a very economical advantage that the production is performed by a simpler process to improve product manufacturability and productivity.

Claims (1)

In a single phase non-commutator motor in which a plurality of iron pieces of a flat plate are stacked so that magnets are provided opposite to an outer end of a core seated on an outer circumferential surface of a holder. Single phase non-commutator motor of the core (30) opposite the magnet (61) opposite one end portion of the salient pole 32 so that the thickness is reduced by cutting a part of the iron piece.