JPH0654474A - Brushless dc motor - Google Patents

Abstract

PURPOSE:To provide a brushless DC motor which can prevent the deformation of a coil by the residual stress occurring in the coil line material after molding of the coil and can use a coil, even if it is one with a great difference between the long side and the short side or one with an acute angle, without an hindrance, and besides which can reduce windage loss as well as absorb the vibration or noise caused by the alternation of Faraday force. CONSTITUTION:A flat type of brushless DC motor is constituted such that a coil being gotten by winding a line material for a coil on a bobbin made of resin is arranged on a coil yoke 3, the resin bobbin 4 and all.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat type brushless DC motor, and more particularly to a coil reel material and its shape.

[0002]

2. Description of the Related Art Conventional flat type brushless DC
The motor adopts a coreless type in which a coil wire is wound around a winding frame made of steel and then the winding frame is removed.

[0003]

However, in the above-mentioned prior art, after the winding frame is removed, residual stress is present in the coil wire material, so that the coil is deformed and the difference between the long side and the short side is particularly large. This may hinder the formation of the coil and the use of the coil having an acute angle.

In some cases, the coil is formed into a shape that is easy to manufacture and then press-molded again. According to this,
The number of man-hours for manufacturing the motor increases.

Further, when the coil is arranged on the coil yoke, it is troublesome to use a jig for coil positioning, and a space is required to secure an insulation distance from the outer shell of the motor. Will increase.

Further, in the flat type motor, torque is applied in the direction perpendicular to the current flowing in the coil, and the torque direction applied to the coil wire material is reversed by switching the NS pole of the permanent magnet, so that minute vibrations are applied to the coil. Occurs, which causes noise and vibration of the motor, which is a problem, and in the coreless structure, wind loss occurs in the coil air-core portion, which causes deterioration of the motor performance.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention is a flat type brushless DC motor, in which a coil wire is wound around a winding frame to form a resin as a winding frame. Use the molded one,
The coil obtained as described above is arranged on the coil yoke together with the resin winding frame.

According to another means of the present invention, the shape of the resin-molded bobbin is added to the shape of the resin bobbin by an extension distance for insulation in order to secure an insulation distance between the coil and the motor shell. In point.

Another means of the present invention is that the resin winding frame is fan-shaped, the fan-shaped resin winding frames are combined adjacent to each other, and a coil is arranged on the circumference thereof.

Further, another means of the present invention is that a recess corresponding to the shape for the coil yoke to generate cogging is formed on the side of the resin winding frame where the coil yoke is provided.

[0011]

That is, according to the present invention, a flat type brushless DC motor is obtained as described above by using a resin-molded winding frame for winding the coil wire around the winding frame. By arranging the coil together with the resin winding frame on the coil yoke, the coil deformation, which was a problem in the conventional coreless type brushless DC motor, that is, the coil deformation due to the residual stress generated in the coil wire after coil molding, is eliminated. In this case, it is absorbed by the resin winding frame interposed in the air-core part.

Further, the pressing process for correcting coil deformation in the case of coreless, which has been conventionally performed in part, is also reduced.

Further, the coil deformation due to the residual stress generated in the coil wire after coil forming is absorbed by the resin winding frame interposed in the air core portion in the case of coreless, so that the coil having a large difference between the long side and the short side can be obtained. Even if the coil is formed or has an acute angle, these coils can be used without any trouble.

Further, since the resin is present in the air-core portion, it is possible to absorb the vibration and noise generated by the alternation of the Faraday force and at the same time reduce the wind loss.

Further, according to the present invention, the resin winding frame also serves as an insulating spacer for ensuring an insulation distance between the coil and the outer casing of the motor. In other words, the resin winding frame serves to increase the insulation distance between the coil and the outer casing of the motor. If secured, a spacer for securing an insulation distance from the outer shell of the motor is not required, and a process therefor is not required.

Further, according to the present invention, the resin winding frame has a fan shape, and if the fan-shaped resin winding frames are arranged next to each other, the coil is arranged on the circumference, and therefore the positioning of the coil is performed. No special jig is used to do this, and no assembly process is required.

Further, according to the present invention, if a recess corresponding to the shape for causing the coil yoke to generate cogging is provided on the side of the resin winding frame where the coil yoke is provided, the coil yoke for generating cogging can be obtained. Accurate positioning can be easily performed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a brushless DC motor which is an embodiment of the present invention.

A housing 1 forming the outer contour of the motor,
A bearing 2 press-fitted and held in the bearing portion of the housing 1, a coil yoke 3 for closing the magnetic flux of the permanent magnet 7, and a coil 5 wound and held on a resin winding frame 4 arranged on the coil yoke 3. A motor is constituted by a magnet yoke 6 that closes the external magnetic flux of the permanent magnet 7 and is used as a rotor outer shell of the motor, and a shaft 8 that is press-fitted and held in the magnet yoke 6 and disposed in the bearing 2.

FIG. 2 is an exploded view of the Faraday force of the coil, which is an example of the technical problem to be solved by the present invention, corresponding to the magnetic flux generated by the permanent magnet.

In FIG. 2, assuming that a current flows in one direction in the coil, the Faraday force produced by the magnetic flux of the permanent magnet has a component in the direction of the arrow.

When the motor rotates, the position of the NS pole changes, so that at the same point on the coil, the directions of the forces alternate in opposite directions. In the coreless coil, since there is no core that absorbs this force, the vibration generated in the coil directly leads to the vibration and noise of the motor.

Further, as shown in FIG. 2, when a coreless coil is formed with an acute-angled portion, residual stress during coil forming exists in the corner portion. Coils that are not completely attached will deform and become defective or must be press molded and straightened.

In the present invention, the winding frame around which the coil wire is wound is molded with resin, and after the coil is filled, it is placed on the coil yoke as it is, so that the vibration noise due to the Faraday force is buffered by the resin winding frame and the coil remains. The force of deformation due to the stress can also be received by the resin winding frame.

FIG. 3 shows a second embodiment of the present invention. In this embodiment, the resin winding frame 11 is formed also as an insulating spacer for ensuring an insulation distance between the coil and the motor outer shell. .

That is, the resin winding frame 11 is provided with a groove portion filled with the coil wire material 12, and the coil wire material 12 is filled in the groove portion.

The extension distance L from the outer diameter end face of the coil wire filling groove portion to the coil yoke 13 is a distance that can sufficiently secure the insulation distance defined by the Electrical Appliance and Material Control Law.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, the fan-shaped resin reel 21 has an engaging projection 23 and an engaging recess 24 when they are arranged next to each other. Is added, by arranging the fan-shaped resin reels next to each other, the coil is arranged on the circumference, therefore without using a special jig to position the coil,
Moreover, the assembly process for that is also unnecessary.

Further, as shown in FIG. 4, the arrangement structure of the coil can be adjusted by combining the resin winding frame in which the coil 22 is arranged and the resin winding frame 21 in which the coil is not arranged. By combining a plurality of the resin winding frames, the coils are arranged on the circumference and the positioning jig is not required.

FIG. 5 shows a fourth embodiment of the present invention. In this embodiment, the coil yoke mounting side 31 of the resin winding frame is shown.
In addition, the coil yoke 32 is provided with a recess conforming to the shape for generating cogging. According to this configuration, accurate positioning of the coil yoke 32 for generating cogging can be easily performed. .

[0032]

As described above, according to the present invention, in the flat type brushless DC motor, a resin molding is used as the winding frame when the coil wire is wound around the winding frame to be obtained as described above. By disposing the formed coil together with the resin winding frame on the coil yoke, the coil deformation, which is a problem in the conventional coreless type brushless DC motor, that is, the coil deformation due to the residual stress generated in the coil wire after coil forming, can be performed. In the case of coreless, it can be absorbed by the resin winding frame interposed in the air-core part.

Further, it is possible to reduce the pressing process for correcting the coil deformation in the case of coreless, which is conventionally performed in part.

Further, the coil deformation due to the residual stress generated in the coil wire after coil forming is absorbed by the resin winding frame interposed in the air-core portion in the case of coreless, so that the coil having a large difference between the long side and the short side can be obtained. Even if the coil is formed or has an acute angle, these coils can be used without any trouble.

Further, since the resin is present in the air-core portion, it is possible to absorb the vibration and noise generated by the alternating Faraday force and at the same time reduce the wind loss.

Further, according to the present invention, the resin winding frame also serves as an insulating spacer for ensuring an insulation distance between the coil and the motor outer casing. In other words, the resin winding frame serves to increase the insulation distance between the coil and the motor outer casing. If secured, a spacer for securing an insulation distance from the outer shell of the motor is not required, and a process therefor is not required, and the motor manufacturing process can be reduced.

Furthermore, according to the present invention, the resin winding frame has a fan shape, and if the resin winding frames having the fan shape are arranged next to each other, the coil is arranged on the circumference, and therefore the positioning of the coil is performed. Therefore, a special jig is not used, and an assembling process therefor is not necessary, and the manufacturing process of the motor can be reduced.

Furthermore, according to the present invention, a coil yoke for generating cogging can be provided by providing a recess on the side of the resin winding frame on which the coil yoke is disposed, the recess being matched with the shape for causing the coil yoke to generate cogging. Accurate positioning can be easily performed, which also contributes to shortening the time required for the motor manufacturing process.

[Brief description of drawings]

FIG. 1 is a side view of a brushless DC motor that is an embodiment of the present invention.

FIG. 2 is an exploded view of a Faraday force applied to a coil, which is one of the problems to be solved by the present invention.

FIG. 3 is an insulating structure diagram of a resin reel according to a second embodiment of the present invention.

FIG. 4 is a plan view of a fan-shaped resin reel according to a third embodiment of the present invention.

FIG. 5 is a coil yoke side view of a resin reel according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Bearing, 3 ... Coil yoke, 4 ... Resin winding frame, 5 ... Coil, 6 ... Magnet yoke, 7 ... Permanent magnet, 8 ... Shaft, 11 ... Resin winding frame, 12 ... Coil wire, 13 ... coil yoke, 21 ... fan-shaped resin reel, 2
2 ... Coil, 23 ... Engagement convex part, 24 ... Engagement concave part, 31 ...
The coil yoke mounting side of the resin reel, 32 ... Coil yoke.

Claims (4)

[Claims] 1. A disk-shaped permanent magnet magnetized into a plurality of poles is arranged on the rotor side, and on the stator side opposite to the rotor side, the permanent magnet is planarly opposed to the permanent magnet in order to close the magnetic flux of the permanent magnet. A coil yoke is arranged, and a plurality of iron-free core coils each having a fan shape are arranged on the coil yoke (this structure is hereinafter referred to as a flat type). In the brushless DC motor that rotates the rotor by using a sensor capable of passing a current in the forward direction if it senses N pole and in the reverse direction if it senses S pole, and reciprocally energizing the coil by the output of this sensor, The coil is formed by winding a coil wire around a resin-molded winding frame, and the coil is arranged in the coil yoke together with the resin winding frame. 2. The brushless DC motor according to claim 1, wherein the resin winding frame also serves as an insulating spacer that secures an insulating distance between the coil and the motor shell. 3. The brushless DC system according to claim 1 or 2, wherein the resin winding frame is fan-shaped, the fan-shaped resin winding frames are combined adjacent to each other, and a coil is arranged on the circumference thereof.
motor. 4. The brushless DC motor according to claim 1, wherein the coil yoke has a recess on the side of the resin winding frame on which the coil yoke is disposed, the recess being matched to the shape for causing the coil yoke to generate cogging.