KR101170156B1 - Slotless Stator Core manufacturing method on Brushless DC Motor. - Google Patents

Abstract

The present invention relates to a method for manufacturing a slotless stator configured in a brushless motor, and more particularly, after injection molding a bobbin in which a plurality of coil winding protrusions are formed to protrude at regular intervals along a circumference, the coils are respectively formed. In winding the coil winding protrusion of the coil, a large amount of coils can be wound in the longitudinal direction of the rotating shaft, so that a high-power DC motor can be supplied and a bobbin is formed of an insulating material to generate a force that interferes with the rotation generated in the rotor. By avoiding this, the efficiency of the high output can be further increased, and the brushless motor can solve the problems of the complexity of the manufacturing process for manufacturing the coil winding body wound on the conventional brushless DC motor and the difficulty of mass production. The present invention relates to a slotless stator manufacturing method.
Slotless stator manufacturing method configured in the brushless motor of the present invention,
In the slotless stator manufacturing method constituted by a brushless motor,
A bobbin injection molding product manufacturing step (S110) of injection molding a plurality of coil winding protrusions by inserting an insulating material into an injection molding frame having a bobbin shape formed to protrude at regular intervals along a circumference;
A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;
It characterized in that it comprises a; bobbin insertion step (S130) for inserting the coil wound bobbin into the housing.
Through the present invention, the complexity of the manufacturing process for manufacturing a slotless stator including a coil winding wound on a conventional brushless DC motor and the difficulty of mass production can be solved, thereby simplifying the motor manufacturing process and mass productivity. Will be provided.

Description

Slotless stator core manufacturing method on Brushless DC Motor.

The present invention relates to a method for manufacturing a slotless stator configured in a brushless motor, and more particularly, after injection molding a bobbin in which a plurality of coil winding protrusions are formed to protrude at regular intervals along a circumference, the coils are respectively formed. In winding the coil winding protrusion of the coil, a large amount of coils can be wound in the longitudinal direction of the rotating shaft, so that a high-power DC motor can be supplied and a bobbin is formed of an insulating material to generate a force that interferes with the rotation generated in the rotor. By avoiding this, the efficiency of the high output can be further increased, and the brushless motor can solve the problems of the complexity of the manufacturing process for manufacturing the coil winding body wound on the conventional brushless DC motor and the difficulty of mass production. The present invention relates to a slotless stator manufacturing method.

Brushless DC motors (hereinafter referred to as BLDC motors) are characterized by the absence of mechanical contacts such as brushes and commutators compared to conventional DC motors with brushes. It is widely used due to long life and development of semiconductor technology and components and materials.

In the brushless DC motor, a rotor is formed at an inner center thereof, and a stator is configured in a form of surrounding the rotor so that the rotor rotates in the stator.

A general electric motor is configured to form a protrusion and a slot in the axial length direction at regular intervals on the inner circumference of the stator and to induce a magnetic field by winding a coil inside the slot. It takes a lot of force, time, and complicated devices, as well as the presence of the projections create a discontinuous magnet and limit the number of windings, which has the disadvantage of affecting the efficiency of the motor.

Therefore, the method of increasing the efficiency and reducing the losses caused by hysteresis by securing the number of effective conductors required by the motor by filling the entire area of the stator with a coil has been proposed. Is equipped with a hex-shaped end that is longer than the length of the other side, winding three coils on the outer side, and then removing the end.

After removing the stem, press the formed coil in the oblique direction as in the form of the stem to make the coil form a flat double overlap.

After that, the coil winding body for the stator is made by forming the diameters of the inner and outer surfaces so that the rotor can be inserted into the inside of the motor while the two ends are overlapped.

This method can achieve the purpose of improving the efficiency of the motor by forming a coil and a projection is not formed in the stator, but the whole is made of a coil, but a lot of defects occur and precise and special devices were required to prevent this.

In other words, in the process of winding the coil on the end and pressing it flatly, if it is wrong, the coil may not be able to maintain a uniform and aligned winding state and may be entangled. Such a result may cause a fatal effect on the performance of the motor. In the process of forming this in the form of a round tube again, since the inner and outer diameters are not uniform after molding, there is a problem that a separate apparatus and process for determining the inner and outer diameters to the required dimensions before assembling the finished product as a motor are required.

Due to such a problem, the above-described technology has not been activated due to poor production efficiency due to waste of time, manpower, equipment, etc. despite the advantages of improving performance as a motor.

To improve the above problems, as shown in FIG. 2, the winding drum 1 has a diameter equal to the diameter of the stator that the rotor rotates to form a through hole, and a plurality of incision grooves 3 are formed by a predetermined length from both ends. ) Is configured at an equal angle, and each cutting groove (3) constitutes a hook pin 10 that can be placed at the same time and inserts an action pin (20) to enable the hanger of the hook pin (10) in the working hole. Although it discloses a stator coil winding device for a brushless motor, which has a problem of taping, securing an inner diameter using a sizing rod, and applying a varnish, the manufacturing process may have a complex problem and the biggest problem that mass production is impossible. There was only.

Therefore, in providing a slotless stator, there is a demand for a technology capable of manufacturing convenience and mass production and at the same time supplying a high power DC motor.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art,

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of complexity and difficulty in mass production of a manufacturing process for manufacturing a slotless stator including a coil winding wound on a conventional brushless DC motor, thereby simplifying and massifying a motor manufacturing process. To provide productivity.

Another object of the present invention is to allow a large amount of coil to be wound on the bobbin in the longitudinal direction of the rotary shaft to enable a high power DC motor supply.

Still another object of the present invention is to form a bobbin with an insulating material so that a force that prevents rotation generated in the rotor is not generated, thereby further increasing the efficiency of the high output.

In order to achieve the problem to be solved by the present invention, the slotless stator manufacturing method is configured in a brushless motor according to an embodiment of the present invention,

In the slotless stator manufacturing method constituted by a brushless motor,

A bobbin injection molding product manufacturing step (S110) of injection molding a plurality of coil winding protrusions by inserting an insulating material into an injection molding frame having a bobbin shape formed to protrude at regular intervals along a circumference;

A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;

It characterized in that it comprises a; bobbin insertion step (S130) for inserting the coil wound bobbin into the housing.

As described above, the slotless stator manufacturing method of the brushless motor of the present invention,

The complexity of the manufacturing process for manufacturing a slotless stator including a coil winding wound on a conventional brushless DC motor and the difficulty of mass production are solved, thereby simplifying the motor manufacturing process and providing mass productivity. .

In addition, a large number of coils can be wound on the bobbin in the longitudinal direction of the rotating shaft, thereby providing an effect capable of supplying a high output DC motor.

In addition, the bobbin is formed of an insulating material so that a force that prevents rotation generated in the rotor is not generated, thereby providing a better effect of doubling the efficiency of the high output.

1 is a process diagram showing the steps of manufacturing a slotless stator constructed in a conventional brushless motor.
2 is a perspective view showing a stator coil winding apparatus used to manufacture a slotless stator constructed in a conventional brushless motor.
3 is a perspective view showing a sizing rod used to manufacture a slotless stator constructed in a conventional brushless motor.
Figure 4 is a process diagram showing a slotless stator manufacturing method configured in a brushless motor according to an embodiment of the present invention.
5 is a process chart showing a slotless stator manufacturing method configured in a brushless motor according to another embodiment of the present invention.
Figure 6 is an exemplary view showing a slotless stator manufacturing method configured in a brushless motor according to an embodiment of the present invention.
7 is a perspective view illustrating a bobbin and an insulator that are injection molded in a slotless stator manufacturing method of a brushless motor according to an embodiment of the present invention.
8 is an exploded perspective view showing a brushless DC motor including a bobbin and an insulator injection-molded in the slotless stator manufacturing method of the brushless motor according to an embodiment of the present invention.
9 is a combined perspective view of a brushless DC motor including a bobbin and an insulator injection-molded in the slotless stator manufacturing method of the brushless motor according to an embodiment of the present invention.
FIG. 10 is a plan view illustrating a rotor inserted into a bobbin that is injection molded in a slotless stator manufacturing method of a brushless motor according to an exemplary embodiment of the present invention.

Slotless stator manufacturing method is configured in a brushless motor according to an embodiment of the present invention for achieving the above object,

In the slotless stator manufacturing method constituted by a brushless motor,

A bobbin injection molding product manufacturing step (S110) of injection molding a plurality of coil winding protrusions by inserting an insulating material into an injection molding frame having a bobbin shape formed to protrude at regular intervals along a circumference;

A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;

It characterized in that it comprises a; bobbin insertion step (S130) for inserting the coil wound bobbin into the housing.

On the other hand, the slotless stator manufacturing method configured in the brushless motor according to another embodiment of the present invention,

A plurality of coil winding projections are formed to protrude at regular intervals along the circumference, and includes a fixing projection formed to protrude so as to be inserted and fixed to the groove portion formed in the first and second insulators on both sides of the coil winding projections. A bobbin injection molding manufacturing step (S110) of inserting an insulating material into an injection molding mold having a bobbin shape configured to perform injection molding;

An insulator injection molding manufacturing step (S115) of inserting an insulating material into an injection molding mold having an insulator shape including a recess formed to insert and fix the fixing protrusion formed on the bobbin;

A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;

A bobbin insertion step of inserting the coil wound around the coil into a housing (S130);

And an insulator coupling step (S140) for inserting and fixing the fixing protrusion exposed to the outside of the housing to the recess formed in the insulator.

At this time, the coil winding projection of the injection-molded bobbin,

It is characterized in that it is formed parallel to the longitudinal direction of the axis of rotation.

At this time, in the coil winding step (S120),

The coil to be wound is characterized in that it is wound in parallel with the longitudinal direction of the rotating shaft.

At this time, the housing,

It is characterized in that the silicon steel sheet is a laminated core.

At this time, the housing,

Forming a plurality of housing grooves parallel to the longitudinal direction of the rotating shaft at regular intervals along the circumference of the inner surface, characterized in that the coil winding projection is inserted and fixed to the formed housing grooves.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the slotless stator manufacturing method of the brushless motor of the present invention.

1 is a process diagram showing the steps of manufacturing a slotless stator constructed in a conventional brushless motor.

2 is a perspective view showing a stator coil winding apparatus used to manufacture a slotless stator constructed in a conventional brushless motor.

3 is a perspective view showing a sizing rod used to manufacture a slotless stator constructed in a conventional brushless motor.

As shown in Figure 1, the step of manufacturing a slotless stator configured in a conventional brushless motor,

A first taping step (S10) of first taping the insulating tape at a position where the coil of the stator coil winding device is to be wound;

A coil winding step (S20) of winding a coil on the first taped insulating tape;

A secondary taping step (S30) of secondary taping an insulating tape on the wound coil;

A tertiary taping step (S40) of separating the primary and secondary taped coils from the stator coil winding apparatus and tertiarily taping the insulating tape on the secondary taped insulating tape;

A coil pressing step (S50) of pressing the third taped coil using a pressing tool;

A coil insertion step of inserting the compressed coil into a lamination core (S60);

Inside coil sizing step (S70) to secure the inner diameter by inserting a sizing rod into the lamination core;

A varnish coating step (S80) of applying a varnish epoxy to cure the coil to the lamination core and inserting the sizing rod to cure at high temperature;

And removing the sizing rod from the high temperature hardened lamination core to complete the slotless stator (S90).

Specifically, the coil is wound around the stator coil winding apparatus shown in FIG. 2, which has a diameter equal to the diameter of the stator in which the rotor rotates and has a winding drum 1 through which a working hole is formed. It consists of a plurality of incision grooves (3) at equal angles by a constant length from both ends, and each incision groove is configured with a hook pin (10) that can be placed at the same time, the inlet and out of the working hole It will insert the action pin 20 to enable.

In addition, the outer surface of the winding drum (1) is located a little inward of the rear end of the hanger pin (10) to form a tightening groove (4) and then insert the fastener ring (5) of elastic material to the hook pin (10) It is configured to be crimped.

The insulating tape is first taped (S10) at a position where the coil of the stator coil winding device is to be wound.

After that, the coil is wound around the primary taped insulating tape (S20), and the insulating tape is secondary taped (S30) on the wound coil.

The secondary taping is to securely hold the coil after winding the coil.

In addition, after the primary and secondary taped coils are separated from the stator coil winding device, the third taping (S40) is performed with an insulating tape on the secondary taped insulating tape.

As described above, the third taping is to press the coil flatly during the subsequent pressing process, so if the wrong is done, the coil is not taped to maintain a uniform and aligned winding state, and the taping is prevented.

Thereafter, the third taped coil is compressed using a pressing tool (S50).

Since the technique of crimping the coil by the crimping tool is already well known to those skilled in the art, a detailed description thereof will be omitted.

Thereafter, the compressed coil is inserted into a lamination core (S60), and the configuration of the lamination core 500 is already well known to those skilled in the art, and thus the description thereof is omitted in the present invention and performs the same function as the housing of the present invention. something to do.

Thereafter, the inside coil sizing step (S70) of inserting a sizing rod into the lamination core to secure an inner diameter is performed, and the sizing rod 50 represents an apparatus as shown in FIG. 3.

In the conventional process that goes through the process as described above, if the wrong winding in the process of pressing the coil flat after winding, the coil may not maintain a uniform and aligned winding state and entanglement may occur, and this result is fatal to the performance of the motor. In the process of shaping this into a round tube, the inner and outer diameters are not uniform after molding, so a separate device and process are required to determine the inner and outer diameters to the required dimensions before assembling the finished product as a motor. Still had to have.

As described above, the conventional technologies inevitably lead to complexity in the manufacturing process and thus provide a fatal disadvantage in that mass production is impossible.

On the other hand, the present invention can provide an advantage that can simultaneously provide a long-term unsolved problem of those skilled in the art to secure mass productivity and simplify the manufacturing process.

Meanwhile, after inserting the sizing rod after the inside coil sizing step (S70), varnish epoxy is applied to the entire lamination core to fix the coil to the lamination core, and then subjected to high temperature curing (S80). Removing the sizing rod from the slotless stator is completed (S90).

The varnish epoxy coating described above is a process for preventing the coil from being spaced apart from the lamination core.

In conclusion, the prior art still has problems in fixing as a result of how the coil can be securely fixed to the lamination core.

In addition, in order to solve the complexity of the manufacturing process that goes through nine process steps and nine processes, the increase in labor cost and manufacturing cost is natural and mass production itself was impossible.

Figure 4 is a process diagram showing a slotless stator manufacturing method configured in a brushless motor according to an embodiment of the present invention.

As shown in Figure 4, the slotless stator manufacturing method configured in the brushless motor according to an embodiment of the present invention,

In the slotless stator manufacturing method constituted by a brushless motor,

A bobbin injection molding product manufacturing step (S110) of injection molding a plurality of coil winding protrusions by inserting an insulating material into an injection molding frame having a bobbin shape formed to protrude at regular intervals along a circumference;

A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;

It characterized in that it comprises a; bobbin insertion step (S130) for inserting the coil wound bobbin into the housing.

The bobbin has a configuration for providing a slotless stator to enable the manufacturing convenience and high power DC motor supply.

On the other hand, the slotless stator of the present invention may mean that it is composed of a bobbin and a housing, it may also mean that it is composed of a bobbin, a housing and an insulator.

On the other hand, as shown in Figure 8 the injection molding bobbin 200 which is the most important component of the present invention,

A body portion 220 having a through hole 210 formed therein for inserting the rotor 100,

A plurality of coil winding protrusions 230 are formed on the outer circumferential surface of the body portion at regular intervals along the circumference to wind the coil 300, and prevent the coils to be spaced apart from each other. To this end, the coil winding protrusion may further include a fixing protrusion 240 formed to protrude so as to be inserted into and fixed to the recess 410 formed in the first insulator 400 and the second insulator 400a.

The bobbin configured as described above has a large number of coil winding protrusions capable of winding the coil so as to protrude at regular intervals along the circumference of the outer circumferential surface of the bobbin body portion, so that a large number of coils can be wound in the longitudinal direction of the rotating shaft so that a high output DC The motor supply will provide the advantage possible.

As shown in the figure, the coil winding protrusion 230 is formed to protrude along the outer circumferential surface of the body portion and to be parallel to the longitudinal direction of the body portion.

The coil 300 is wound around the formed coil winding protrusion, but the fixing protrusions are formed on both sides to prevent the wound coil from flowing out.

When the fixing protrusion is formed as described above, a space is formed between the outer circumferential surface of the body portion and the fixing protrusion so that the coil can be stably wound.

In addition, the fixing protrusion may be inserted into and fixed to the recess 410 formed in the first and second insulators 400 and 400a, thereby eliminating the phenomenon that one bobbin rotates only when the rotor rotates.

In addition, by inserting an insulating material into the injection mold of the bobbin-shaped injection molding it may be formed of a plastic material, for example, as shown in the drawing can be manufactured by injection molding the bobbin rotation generated in the rotor By preventing the force generated from interfering with each other, the efficiency of the high output can be further increased, and the manufacturing process for manufacturing the coil winding body wound on the conventional brushless DC motor and the manufactured coil winding body to the lamination core The complexity of the inserting process and the difficulty of mass production can be solved, thereby simplifying the motor manufacturing process and providing mass productivity.

By inserting an insulating material into an injection molding mold having a bobbin shape having the above configuration, injection molding (S110) is performed to manufacture a bobbin.

Thereafter, the coils are wound around the coil winding protrusions of the injection-molded bobbin using a coil winding device, respectively (S120).

The coil winding device refers to a coil winding device commonly used by those skilled in the art, and a configuration and a coil winding method thereof are already known to those skilled in the art, so a detailed description thereof will be omitted.

Subsequently, the coil wound around the bobbin is inserted into the housing (S130) to finally complete the slotless stator configured in the brushless motor.

As shown in FIG. 6, since the coil is wound around the bobbin configured with the coil winding protrusion that can stably fix the coil, the coil is directly inserted into the housing (the same as the conventional lamination core) without a separate manufacturing process. The manufacturing process is simple, and the coil can be securely fixed to the housing, and at the same time, the assembly line capable of mass production can be provided, enabling mass production, thereby solving problems that remain long-term problems for those skilled in the art. will be.

5 is a process chart showing a slotless stator manufacturing method configured in a brushless motor according to another embodiment of the present invention.

On the other hand, Figure 5 is a slotless stator manufacturing method configured in a brushless motor according to another embodiment of the present invention,

A plurality of coil winding projections are formed to protrude at regular intervals along the circumference, and includes a fixing projection formed to protrude so as to be inserted into the grooves formed in the first and second insulators on both sides of the coil winding projections. A bobbin injection molding manufacturing step (S110) of inserting an insulating material into an injection molding mold having a bobbin shape configured to perform injection molding;

An insulator injection molding manufacturing step (S115) of inserting an insulating material into an injection molding mold having an insulator shape including a recess formed to insert and fix the fixing protrusion formed on the bobbin;

A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;

A bobbin insertion step of inserting the coil wound around the coil into a housing (S130);

And an insulator coupling step (S140) for inserting and fixing the fixing protrusion exposed to the outside of the housing to the recess formed in the insulator.

The manufacturing step as described above is to provide a slotless stator to prevent the separation of the coil through the insulator and at the same time stably fixed to the housing when forming the fixing projection on the bobbin.

That is, the bobbin 200 is injection molded in the molding die,

A plurality of coil winding projections 230 are formed to protrude at regular intervals along the circumference, and in the groove 410 formed in the first insulator 400 and the second insulator 400a on both sides of the coil winding projections. It has a shape configured to include a fixing protrusion 240 is formed to protrude so as to be fixed.

It is obvious that the spacing of the recesses should coincide with the spacing of the fixing protrusions.

Specifically, a plurality of coil winding protrusions are formed to protrude at regular intervals along the circumference, and protrude so that the coil winding protrusions are inserted into and fixed to recess portions formed in the first and second insulators on both sides of the coil winding protrusions. By inserting an insulating material into an injection molding mold having a bobbin shape including a fixing protrusion formed to be formed to be injection molded to produce a bobbin injection molding (S110).

Thereafter, an insulating material is put into an injection molding mold having an insulator shape including an recess formed to insert and fix the fixing protrusion formed on the bobbin (S115).

Subsequently, each coil is wound around the coil winding protrusion of the injection molded bobbin using a coil winding device (S120), and the bobbin wound around the coil is inserted into the housing (S130), and exposed to the outside of the housing. The fixed protrusion is inserted into and fixed to the recess formed in the insulator (S140).

Brushless DC motor having a slotless stator manufactured as described above,

As shown in FIG. 8, a rotor 100 including a rotating shaft 110 and magnetic poles 120 alternately arranged at regular intervals on at least one pair of N-poles and S-poles on an outer circumferential surface of the rotating shaft. Wow; A bobbin 200 for inserting the rotor into the through hole; A first insulator 400 and a second insulator 400a into which the fixing protrusions formed in the bobbin are inserted; A housing 500 having a bobbin through hole for inserting the bobbin therein; A front cover 600 and a rear cover 600a coupled to both sides of the housing; Consists of fixing the housing and the front cover and the rear cover tightly to prevent the separation of the parts (700);

The housing is formed with a bobbin through hole 510 for inserting the bobbin, and on the outer surface there is formed a cover coupling protrusion 530 for coupling the front cover and the rear cover.

In addition, the inner surface of the housing to form a plurality of housing grooves 510 in parallel with the longitudinal direction of the rotation axis at regular intervals along the circumference, and is inserted into the coil winding projections of the bobbin to the housing groove formed.

The front cover 600 and the rear cover 600a are coupled to both sides of the housing, and a hole is formed in the center of the covers so that the rotation shaft can pass therethrough.

In addition, the outer cover 700 is configured to firmly secure the housing, the front cover, and the rear cover to prevent separation of components, and the clip groove 620 is provided at the front cover 600 and the rear cover 600a. It is formed to be fixed by inserting an external clip (see Figure 9).

Through the manufacturing method as described above, the complexity of the manufacturing process for manufacturing the slotless stator including the coil winding body wound on the conventional brushless DC motor and the difficulty of mass production can be solved, thereby simplifying the motor manufacturing process. And mass productivity.

It will be appreciated by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not restrictive.

The scope of the invention is indicated by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the invention. do.

100: rotor
110: rotation axis
120: stimulation unit
200: bobbin
210: through hole
220: body portion
230: coil winding projection
240: fixing protrusion
300: coil
400: first insulator
400a: second insulator
410: groove
500 housing
510: bobbin through hole
520: Housing groove
530: protrusion for cover coupling
600: front cover
600a: rear cover
610: Cover groove
620: Clip groove
700: outer clip

Claims (6)

delete A plurality of coil winding projections are formed to protrude at regular intervals along the circumference, and includes a fixing projection formed to protrude so as to be inserted and fixed to the groove portion formed in the first and second insulators on both sides of the coil winding projections. A bobbin injection molding manufacturing step (S110) of inserting an insulating material into an injection molding mold having a bobbin shape configured to perform injection molding;
An insulator injection molding manufacturing step (S115) of inserting an insulating material into an injection molding mold having an insulator shape including a recess formed to insert and fix the fixing protrusion formed on the bobbin;
A coil winding step (S120) of winding coils respectively by using a coil winding device on each coil winding protrusion of the injection-molded bobbin;
A bobbin insertion step of inserting the coil wound around the coil into a housing (S130);
And an insulator coupling step (S140) for inserting and fixing the fixing protrusion exposed to the outside of the housing to the recess formed in the insulator.
Coil winding projection of the injection-molded bobbin,
It is formed parallel to the longitudinal direction of the axis of rotation,
In the coil winding step (S120),
The coil to be wound is a slotless stator manufacturing method comprising a brushless motor, characterized in that wound in parallel to the longitudinal direction of the rotating shaft.
delete delete delete The method of claim 2,
The housing includes:
Slotless stator constituting the brushless motor, characterized in that a plurality of housing grooves are formed parallel to the longitudinal direction of the rotation axis at regular intervals along the circumference of the inner surface, the coil winding projection is inserted into the formed housing grooves Manufacturing method.

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