KR100570361B1 - Brushless dc motor having slotless stator - Google Patents

Abstract

The present invention relates to a brushless direct current motor having a slotless stator, and more particularly, to a brushless direct current motor having a slotless stator which is free of cogging torque and which is easy to manufacture coil windings and stators.

A brushless direct current motor having a slotless stator according to the present invention includes a slotless core having a core having a through hole formed in the center thereof and at least one pair of coils wound around the core to be arranged at regular intervals in the circumferential direction of the core. With a stator; A rotor installed inside the slotless stator so that at least one pair of the N pole and the S pole are alternately arranged at regular intervals in the circumferential direction on the outer circumferential surface and the magnetic pole is rotatable opposite to the inner circumferential surface of the slotless stator; In the brushless DC motor having a slotless stator including a, the core is a donut shape, the surface is surrounded by a certain thickness of insulation, the coil is at least one pair or more, at regular intervals in the circumferential direction of the core And a winding wound around the core at a predetermined position in the circumferential direction of the donut-shaped core to be arranged.

Brushless direct current motor, BLDC motor, slotless stator,

Description

Brushless DC Motors with Slotless Stator {BRUSHLESS DC MOTOR HAVING SLOTLESS STATOR}

1 is an exploded perspective view showing a brushless DC motor having a slotless stator according to an embodiment of the present invention;

2 is a cross-sectional view illustrating a slotless stator of a brushless DC motor having a slotless stator according to an embodiment of the present invention.

Figure 3 is a perspective view showing a modification of the slotless stator of the brushless DC motor according to an embodiment of the present invention

Figure 4 is a connection diagram showing the connection of the coil of the slotless stator of the brushless DC motor according to an embodiment of the present invention

5 is a cross-sectional view showing an embodiment of a slot type stator of a conventional brushless DC motor.

6 is a perspective view conceptually illustrating an embodiment of a slotless stator of a conventional brushless DC motor

<Brief description of the major symbols in the drawings>

11,13 first and second housing 20 substrate

30 stator with 31 core

33 Insulation 35 Turning

40 Rotor Assembly 41 Spindle

43 rotor 45,46 bearing

L1-a, L1-b, L2-a, L2-b, L3-a, L3-b coils

The present invention relates to a brushless direct current motor having a slotless stator, and more particularly, to a brushless direct current motor having a slotless stator which is free of cogging torque and which is easy to manufacture coil windings and stators.

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 general, BLDC motors are classified into radial gap type and axial gap type, and radial gap type BLDC motors have outer rotor type according to the arrangement of the magnet rotor. ) And Inner Rotor Type. The present invention is an improvement of the stator of the internal rotor type BLDC motor which is mainly used where the motor structure can be relatively simple and requires relatively sensitive controllability. In general, the internal rotor type BLDC motor is a donut-shaped stator. Inside the stator, a rotor having a cylindrical structure is rotatably supported.

5 conceptually illustrates one embodiment of a conventional internal rotor type BLDC motor having a three-phase, four-pole, six-slot structure. Referring to the drawings, the stator of the BLDC motor has six T-shaped teeth (113) protruding inwardly in the inner side of the annular frame 111, the coil is wound around the tooth 113 The rotor 119, in which two pairs of N poles and S poles are alternately magnetized, is supported by the rotating shaft 118 to be rotatable inside the stator.

However, the conventional BLDC motor requires an expensive dedicated winding machine because the winding operation of the coil is performed by putting the winding jig (JIG) in a narrow slot (Slot, 115) between the teeth 113 and the teeth 113. As a result, the equipment investment costs are high, and the winding time is long, and manufacturing costs increase due to the decrease in productivity. In particular, in the conventional BLDC motor, the gap Gap of the slot 115 for winding the coil on the teeth 113 acts as a factor for generating a cogging torque when the rotor rotates, thereby causing vibration during rotation. This has the disadvantage of occurring.

In order to solve the above problems, the Republic of Korea Patent Publication No. 10-0367478 is inserted into the bobbin coil pre-wound in the outer periphery of the tooth formed in the outer periphery of the core inner ring, and coupled to the core outer ring to seal the bobbin A BLDC motor having a slotless stator of the structure is disclosed.

However, in the conventional BLDC motor having the slotless stator as described above, as the number of teeth increases, not only the coils must be individually wound on the bobbin, but also the cores are separated into the outer and inner rings, and each of them is manufactured separately and combined. This has the added disadvantage of poor productivity. In addition, since the conventional BLDC motor has teeth on the inner ring of the core, the shape thereof is complicated and thus difficult to manufacture.

In addition, the Republic of Korea Patent Publication No. 10-0367478 is to improve the stator of the conventional BLDC motor winding the coil to the bobbin separately to form a coil (formed) with a concave-convex structure outwardly projecting the outer periphery of the core inner ring A BLDC motor is disclosed that has a slotless stator mounted in a slot between a tooth formed and a core coupled to an outer ring.

However, the conventional BLDC motor having the slotless stator has a disadvantage in that a process for forming a coil is additionally required, and a process for joining the inner and outer rings of the core is still added. In addition, the conventional BLDC motor still has a disadvantage in that its fabrication is complicated because the core inner ring has teeth of a complicated shape.

Meanwhile, FIG. 6 conceptually illustrates a slotless stator of a BLDC motor including six coil groups 121 to 126.

However, the slotless stator of the BLDC motor having the conventional slotless stator as described above first winds six coils 121 to 126 by using a winding jig and a dedicated winding machine to form a winding assembly, and then, a winding. The winding assembly was compressed by attaching a fixing tape to maintain the shape of the winding assembly, and then removing the winding assembly from the winding machine, inserting an epoxy coated insulating paper into the winding assembly, and curing the insulating paper by heat treatment while pressing the winding assembly. It is formed by fixing. Therefore, the BLDC motor having the conventional slotless stator undergoes a heat treatment process for the curing of the winding assembly during the manufacture of the stator, and thus, the manufacturing process is complicated, and the winding time is required for each coil group. It has a disadvantage of poor productivity and high production cost because it is longer. In addition, the conventional BLDC motor has a disadvantage in that a large amount of equipment investment is required because a special winding machine and a specially designed winding jig should be used to manufacture the stator. Moreover, the conventional BLDC motor has a problem in that the arrangement of the coil corresponding to the correct pole is difficult and the insulation film of the coil is damaged when the winding assembly and the core or the housing are combined.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a BLDC motor having a slotless stator that is easy to manufacture coil windings and stators as well as no slots that cause cogging torque. .

It is also an object of the present invention to provide a BLDC motor having a slotless stator in which the core coil can be precisely arranged and wound.

A brushless direct current motor according to the present invention for achieving the above object comprises a core having a through hole in the center and at least one pair of coils wound around the core to be arranged at regular intervals in the circumferential direction of the core. With one slotless stator; A rotor installed inside the slotless stator so that at least one pair of the N pole and the S pole are alternately arranged at regular intervals in the circumferential direction on the outer circumferential surface and the magnetic pole is rotatable opposite to the inner circumferential surface of the slotless stator; In the brushless DC motor having a slotless stator including a, the core is a donut shape, the surface is surrounded by a certain thickness of insulation, the coil is at least one pair or more, at regular intervals in the circumferential direction of the core And a winding wound around the core at a predetermined position in the circumferential direction of the donut-shaped core to be arranged.

Since the core is circular without teeth, not only is there no slot, but also the winding of the coil in the core is facilitated.

In addition, the brushless DC motor having a slotless stator according to the present invention, the insulator is injection-molded resin, characterized in that the injection molding to surround the surface of the core in the state that the core is accommodated in the mold. .

By the above configuration, it is possible to easily surround the core with an insulator for insulating the core and the coil.

In addition, in the brushless DC motor having a slotless stator according to the present invention, the insulator may have an upper insulator having an annular groove through which an upper portion of the core may be inserted, and a lower portion of the core may be inserted in the upper portion. Characterized in that the lower insulator formed with an annular groove.

Since the insulator has a removable structure, it is easy to surround the insulator on the core.

In addition, the brushless DC motor having a slotless stator according to the present invention, the outer peripheral surface of the at least one or more projections are formed at regular intervals in the circumferential direction, the coil is formed in the core between the projections. It is characterized in that the winding.

Thus, the coil is wound between positions corresponding to the correct pole, ie between the projections.

Hereinafter, a brushless DC motor having a slotless stator according to the present invention will be described in detail with reference to the embodiment shown in the drawings.

1 is an exploded perspective view showing a brushless DC motor having a slotless stator according to an embodiment of the present invention, Figure 2 is a slotless of a brushless DC motor having a slotless stator according to an embodiment of the present invention Figure 3 is a cross-sectional view showing a stator, Figure 3 is a perspective view showing a modified example of the slotless stator of the brushless DC motor according to an embodiment of the present invention, Figure 4 is a slotless stator according to an embodiment of the present invention It is a connection diagram which shows the wiring of the coil of the stator of the brushless DC motor which has.

Referring to the drawings, a brushless direct current motor having a slotless stator according to the present invention includes housings 11 and 13, a slotless stator 30, and a rotor 43.

The housings 11 and 13 are for accommodating the slotless stator 30 and the rotor 43, and the slotless stator 30 is fixed inside the housings 11 and 13, and the rotor 43 is fixed to the rotation shaft 41 and is supported by the housings 11 and 13 so as to rotate integrally with the rotation shaft 41. Referring to the drawings, the housings 11 and 13 are composed of a first housing 11 and a second housing 13 to have a structure coupled to each other.

The slotless stator 30 includes a donut-shaped core 31 having a through hole formed at a center thereof, and at least one pair of coils wound around the core 31 so as to be arranged at regular intervals in the circumferential direction of the core 31. (L1-a to L3-b) are provided. The outside of the core 31 to which the coils L1-a to L3-b are wound is surrounded by an insulator 33 for insulating the coils L1-a to L3-b and the core 31.

The present invention is characterized in that there is no slot in the stator (30). 1 and 2, the stator 30 includes an annular core 31 surrounded by an insulator 33 having a predetermined thickness on a surface thereof. The core 31 is generally formed by stacking annular iron pieces. The insulator 33 is to insulate the iron core 31 from the coil wound around the core, and is made of an insulating species, a resin, or the like.

Brushless DC motor having a slotless stator according to an embodiment of the present invention as described above is characterized in that the core 31 and the insulator 33 are integrally formed by insert injection (Insert). That is, the core 31 and the insulator 33 may be integrally formed by injection molding the resin of the insulator 33 so as to surround the surface of the core 31 while the core 31 is accommodated in the mold. Can be.

Meanwhile, FIG. 3 illustrates an embodiment in which the insulators are separated into the upper insulator 33a and the lower insulator 33b, and are coupled to each other in a state in which each of the upper and lower parts of the core 31 is accommodated. That is, the insulator has an upper insulator 33a having an annular groove through which the upper part of the core 31 can be inserted, and an annular groove through which the lower part of the core 31 can be inserted. It consists of a lower insulator 33b, and the upper and lower portions of the core 31 are joined to each other by being inserted into each of the annular grooves of the upper insulator 33a and the annular grooves of the lower insulator 33b.
The coils L1-a to L3-b are positioned to be arranged at regular intervals in the circumferential direction on the core 31 insulated by the insulator 33, and wound and wound around the core 31 at that position. The present invention is characterized in that, unlike the stator of the conventional motor, the core is not provided with the coil wound and the slot is not formed by winding the coil around the donut-shaped core itself.

Meanwhile, referring to FIGS. 1 to 3, a brushless DC motor having a slotless stator according to one embodiment of the present invention includes at least one pair of protrusions on an outer circumferential surface of the insulator (33 or 33a, 33b). [(35 or (35a, 35b)] protrudes at regular intervals in the circumferential direction, and the coils L1-a to L3-b are formed between the protrusions (35 or (35a, 35b)). 31. A coil L1-a to L3-b for forming a magnetic field is wound around the core 31 as described below, and the coils L1-a to L3-b are wound. The coil is preferably wound at an exact position corresponding to the magnetic pole, since the protrusions (35 or (35a, 35b)) protrude at regular intervals on the outer circumference of the core, so that the coils have the protrusions ((35 or (35a)). , 35b)] in the correct position.

The coils L1-a to L3-b are wound around the core 31 to form a magnetic field for rotating the rotor 43 in the stator 30. The coils L1-a to L3-b are connected to the core 31 by at least one pair [(L1-a, L1-b) or (L2-a, L2-b) or (L3-a, L3-b )] The abnormality is wound. The figure shows three pairs of coils [(L1-a, L1-b), (L2-a, L2-b), (L3) corresponding to three-phase power sources to form the stator 30 excited by the three-phase power sources. -a, L3-b)] shows an embodiment in which the core 31 is wound, and the present invention is not limited to the embodiment shown in the drawings. The three pairs of coils (L1-a, L1-b), (L2-a, L2-b), and (L3-a, L3-b) are arranged at regular intervals in the circumferential direction of the core 31. And wound around the core 31. On the other hand, Figure 4 shows the connection of the common three pairs of coils ((L1-a, L1-b), (L2-a, L2-b), (L3-a, L3-b)], which is Since the connection is similar to that of a three-phase motor driven by a general three-phase (u, v, w) power source, a detailed description thereof will be omitted.

The rotor 43 constitutes the rotor assembly 40 together with the rotation shaft 41 and bearings 45 and 46 for supporting the rotation thereof. The rotor 43 is magnetized so that at least one pair of N-poles and S-poles are alternately arranged at regular intervals in the circumferential direction on the outer circumferential surface, and the magnetic poles are spaced apart from the inner circumferential surface of the stator 30. It is fixed integrally to the rotating shaft 41 rotatably installed in the housing (11, 13) to rotate in the interior of the. The rotating shaft 41 is supported by the bearings 45 and 46 and installed in the housings 11 and 13.

Reference numeral 20 is a substrate on which a sensor (for example, a hall sensor) or the like for forming the motor driver circuit or detecting the position of the rotor 43 is installed.

Brushless DC motor having a slotless stator according to the present invention having the configuration as described above has the advantage that not only the cogging torque is reduced because there is no slot, but also the winding of the coil and the stator are easy to manufacture.

In addition, the brushless DC motor having a slotless stator according to the present invention has the advantage that the coil can be accurately placed and wound on the core.

The brushless DC motor having the slotless stator described above and shown in the drawings is only one embodiment for implementing the present invention, and should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is defined only by the matters set forth in the following claims, and improvements and modifications of the embodiments without departing from the gist of the present invention will be apparent to those skilled in the art. Will be said to belong to the protection scope of the present invention.

Claims (4)

A slotless stator having a core having a through hole formed in a center thereof and at least one pair of coils wound around the core to be arranged at regular intervals in a circumferential direction of the core; A rotor installed inside the slotless stator so that at least one pair of the N pole and the S pole are alternately arranged at regular intervals in the circumferential direction on the outer circumferential surface and the magnetic pole is rotatable opposite to the inner circumferential surface of the slotless stator; In the brushless DC motor having a slotless stator comprising a, The core is donut-shaped, the surface is surrounded by an insulating material of a certain thickness, And at least one pair of coils, the coil having a slotless stator wound around the core at a predetermined position in the circumferential direction of the donut-shaped core so as to be arranged at regular intervals in the circumferential direction of the core. Reese DC motor. The method of claim 1, The insulator is a resin capable of injection molding, the brushless DC motor having a slotless stator, characterized in that the injection molded to surround the surface of the core in the state that the core is accommodated in the mold. The method of claim 1, The insulator is formed of an upper insulator having an annular groove into which an upper portion of the core can be inserted, and a lower insulator formed with an annular groove into which an lower portion of the core can be inserted. Brushless DC motor with stator. The method according to any one of claims 1 to 3, At least one pair of protrusions are formed on the outer circumferential surface of the insulator at regular intervals in the circumferential direction, And the coil is wound around the core between the protrusions.

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