CN112928846A

CN112928846A - Brushless DC motor

Info

Publication number: CN112928846A
Application number: CN202011405646.XA
Authority: CN
Inventors: 张伟; 汤建军
Original assignee: Positec Power Tools Suzhou Co Ltd
Current assignee: Positec Power Tools Suzhou Co Ltd
Priority date: 2019-12-05
Filing date: 2020-12-04
Publication date: 2021-06-08
Also published as: WO2021110137A1

Abstract

The invention relates to a brushless direct current motor which comprises a rotor, a stator and a plurality of types of windings, wherein the rotor is arranged to rotate around a central axis, the stator is arranged around the outer side of the rotor, the plurality of types of windings are wound on the stator, the plurality of types of windings comprise a plurality of first types of windings and a plurality of second types of windings, the brushless direct current motor further comprises two groups of electric connecting pieces, each type of winding corresponds to one group of electric connecting pieces, and each group of electric connecting pieces is electrically connected with the corresponding winding firstly and then is electrically connected with a. The direct current brushless motor can reduce wiring procedures, thereby improving the manufacturing efficiency, being beneficial to reducing the cost and reducing the whole volume of the direct current brushless motor, and the direct current brushless motor is particularly suitable for being applied to holding tools.

Description

Brushless DC motor

Technical Field

The present invention relates to a brushless dc motor.

Background

With the development of battery technology in recent years, battery powered hand tools, such as drills, grinders, circular saws, have become more and more portable. However, the battery is limited, and the battery cannot be used normally when the battery is used up or fails. Considering that a motor is a power source of an electric tool, for this reason, a direct current brushless motor with two secondary windings is provided in the prior art, and the electric tool using the double-winding motor can be powered by an alternating current power supply and a battery, so that the problem that the tool powered by the battery is unavailable when the battery power is used up or the fault occurs is well solved.

Generally, the connection end of each winding of the brushless dc motor needs to be connected with an enameled wire first, and then electrically connected with a corresponding power line, and as the number of windings increases, the connection frequency of the connection end of the winding inevitably increases in multiples, so that the double-winding motor in the prior art has the problems of complicated wire ends and poor aesthetics.

In order to solve the problem of beauty of the dc brushless motor, chinese patent publication No. CN 207117384U discloses a dc brushless motor terminal, which includes an insulating plate and a terminal arranged on the insulating plate in a protruding and standing manner, and connects a power line and a winding through the terminal, and the terminal is a whole. Although this patent solves the problem of misconnection, it still requires 24 connections. Because each enameled wire is electrically connected with the power line, the steps of peeling off the enamel, jointing, encapsulating, fixing and the like are required, the double-winding motor in the prior art still has the problems of complicated wiring process and low motor manufacturing efficiency.

Disclosure of Invention

The invention aims to provide a direct current brushless motor which is convenient to wire and can improve the manufacturing efficiency.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a brushless DC motor, includes to set up to around a central axis pivoted rotor, enclose and establish the stator in the rotor outside and twine a plurality of types of winding on the stator, a plurality of types of winding include a plurality of first type windings and a plurality of second type windings, brushless DC motor still includes two sets of electric connector, every type the winding corresponds a set of electric connector, every group electric connector earlier with the winding electric connection who corresponds electric connection again in power cord, first type winding is through a set of electric connector is connected with outside first power, the second winding is through another set of electric connector is connected with outside second power.

Further, the electric connecting piece is a metal wire hooking frame which is arranged on the outer side of the stator along the circumferential direction of the stator.

Furthermore, the two groups of metal wire hooking frames are arranged on the outer side of the stator in a pairwise symmetric mode along the circumferential direction of the stator. Furthermore, the motor also comprises a shell for coating the stator, an insulating part is arranged on the outer cylindrical surface of the shell, and the metal wire hooking frame is inserted into the insulating part.

Furthermore, the electric connector is a metal insert, the metal insert is divided into two groups, the number of the metal inserts in each group corresponds to the number of the first type of windings or the number of the second type of windings, and the two groups of metal inserts are respectively arranged on two end faces of the brushless DC motor.

Furthermore, two sets of metal inserting pieces are symmetrically arranged on two end faces of the direct current brushless motor.

Further, the electric connector is a circuit board.

The circuit boards are a first circuit board and a second circuit board, the first circuit board is electrically connected with the first windings respectively, the second circuit board is electrically connected with the second windings respectively, and the first circuit board and the second circuit board are arranged on two end faces of the direct current brushless motor oppositely.

Furthermore, the circuit board comprises a first layer circuit board and a second layer circuit board, which are electrically isolated from each other and arranged on the same side end face of the brushless dc motor, the first layer circuit board is electrically connected with the first windings, and the second layer circuit board is electrically connected with the second windings.

Furthermore, the stator comprises a ring yoke part which is arranged outside the rotor in a surrounding mode and takes the central axis as an axis, and a plurality of tooth parts which are formed in a protruding mode from the ring yoke part towards the rotor direction, and the number of the tooth parts is the same as the sum of the number of the first type of windings and the number of the second type of windings.

Further, the arrangement mode of the first type of winding, the second type of winding and the teeth part is as follows:

the plurality of first-type windings and the plurality of second-type windings are wound on the plurality of tooth parts at intervals;

or, the plurality of first-type windings are sequentially wound on the adjacent tooth parts respectively, and the plurality of second-type windings are sequentially wound on the other adjacent tooth parts respectively.

Further, the arrangement mode of the first type of winding, the second type of winding and the teeth part is as follows: each first type winding and each second type winding are wound on the same tooth part in an overlapping mode, the first type winding is wound on the outer surface of the stator tooth part and is close to the outer surface of the stator tooth part, and the second type winding is wound on the first type winding and is far away from the outer surface of the stator tooth part.

Further, the number of turns of each winding of the first type of winding is different from the number of turns of each winding of the second type of winding, or the wire diameter of each winding of the first type of winding is different from the wire diameter of each winding of the second type of winding.

Further, the number of the plurality of first-type windings is 3, and the number of the plurality of second-type windings is 3.

Further, the first external power source is a direct current power source, and the second external power source is an alternating current power source.

The invention has the beneficial effects that: through set up at least two sets of electric connector in brushless motor, be connected with the winding of different types respectively, brushless motor can connect different external power source, and the internal wiring process is simple, and manufacturing efficiency is high, has avoided unnecessary manufacturing cost's increase. In addition, through optimizing the coil wire winding mode, optimized motor heat dispersion, through adopting electric connector, abandoned the connected mode of traditional enameled wire, avoided the unnecessary increase of the whole volume of motor. The brushless DC motor is particularly suitable for being applied to hand-held tools requiring small motor size.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a schematic structural diagram of a first embodiment of the present invention;

fig. 2 is a schematic structural diagram of the dc brushless motor of fig. 1 in which two types of windings are wound on a stator;

FIG. 3 is a schematic view of the metal wire hooking frame in FIG. 1;

FIG. 4 is a schematic structural diagram of a second embodiment of the present invention;

fig. 5 is a schematic diagram illustrating a structure of the brushless dc motor of fig. 4 in which two types of windings are wound around a stator;

FIG. 6 is a schematic structural diagram of a third embodiment of the present invention;

fig. 7 is a schematic structural diagram of the dc brushless motor of fig. 6 in which two types of windings are wound on the stator.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1 and 2, a brushless dc motor according to a first embodiment of the present invention includes a rotor (not shown) configured to rotate around a central axis, a stator 1 surrounding the rotor, a plurality of types of windings 2 wound around the stator 1, at least two sets of electrical connectors 3, and a housing 4 covering the stator 1. Each type of winding 2 corresponds to a group of electric connectors 3, each group of electric connectors 3 is electrically connected with the corresponding winding 2 first and then is electrically connected to the power line 100, and the power line 100 is used for selectively connecting at least one of at least two external power supplies, wherein the at least two external power supplies comprise an alternating current power supply and a direct current power supply. The stator 1 is surrounded by a ring yoke 11 disposed outside the rotor and having a central axis as an axis, and a plurality of teeth 12 formed to project from the ring yoke 11 in a rotor direction. The plurality of windings 2 includes a plurality of first windings electrically connected to the dc power source via the power line 100 and a plurality of second windings electrically connected to the dc power source via the power line 100 in one embodiment. Generally, the power output requirement of a motor connected to an ac power source is higher than that of a motor connected to a dc power source, and to meet the power requirement, the volume of the second type of winding preferably occupies more than half of the number of windings 2 in the motor.

In order to optimize the output performance of the motor, it is preferable that, in one of the embodiments, the sum of the number of the first windings and the number of the second windings is a multiple of 6, and the number of the teeth 12 is the same as the sum of the number of the first windings and the number of the second windings. In this embodiment, the number of the first-type windings is 3, the number of the second-type windings is 3, and correspondingly, the number of the teeth 12 is 6. Specifically, referring to fig. 2, the first type of winding includes a first winding having two first output terminals U1, a second winding having two second output terminals W1, and a third winding having two third output terminals V1, the first winding, the second winding, and the third winding are respectively connected to an external power line 100 for generating a first magnetic field under the action of a dc power, and the first winding, the second winding, and the third winding are respectively connected to three phases of a power supply through the power line 100 to access different voltages. The 3 windings 2 of the second type comprise a fourth winding with two fourth output terminals U2, a fifth winding with two fifth output terminals W2 and a sixth winding with two sixth output terminals V2. The fourth winding, the fifth winding and the sixth winding are respectively connected with an external power line 100 to generate a second magnetic field under the action of an alternating current power supply, and the fourth winding, the fifth winding and the sixth winding are respectively connected with three phases of the power supply through the power line 100 to access different voltages. In this embodiment, the first type winding 2 and the second type winding 2 are wound on the tooth portion 12 in an overlapping manner, and in detail, the first winding, the second winding and the third winding are sequentially wound on two different tooth portions 12 which are oppositely arranged along the central axis direction; the fourth, fifth, and sixth windings are each sequentially wound on two different teeth 12 that are oppositely disposed in the central axis direction, for example, the teeth 12 include first and second oppositely disposed

teeth

121 and 122, third and fourth oppositely disposed

teeth

123 and 124, and fifth and sixth oppositely disposed

teeth

125 and 126. The first winding is wound on the first tooth part 121 and the second tooth part 122 which are oppositely arranged through a winding wire, and a first output end U1 is led out; the second winding is wound on the third tooth part 123 and the fourth tooth part 124 which are oppositely arranged through a winding wire, and a second output end W1 is led out; the third winding is wound around the fifth tooth 125 and the sixth tooth 126, which are oppositely disposed, by one winding, and exits the third output terminal V1. The fourth winding and the first winding are overlapped on the same tooth part, and are wound on the first tooth part 121 and the second tooth part 122 which are oppositely arranged through a winding wire, and a fourth output end U2 is led out; the fifth winding and the second winding are overlapped on the same tooth part, and are wound on the third tooth part 123 and the fourth tooth part 124 which are oppositely arranged through a winding to lead out a second output end W2; the sixth winding is overlapped with the third winding on the same tooth, and is wound around the fifth tooth 125 and the sixth tooth 126, which are disposed opposite to each other, by one winding, and the third output terminal V2 is drawn. In this embodiment, the windings of the first type of winding and the second type of winding are correspondingly overlapped and wound on the same tooth portion to form a double-layer same-core structure, the inner core is the stator tooth portion 12, the inner layer is close to the outer surface of the stator tooth portion 12, the outer layer is far away from the outer surface of the stator tooth portion 12 to form a structure similar to an onion, the first type of winding is arranged on the inner layer, and the second type of winding is arranged on the outer layer.

In the working process of the brushless motor, for a winding wound on the stator, only the magnetic force generated by the coils arranged in parallel along the axial direction of the motor under the action of current can do work, and the coil parts positioned at the two sides of the end part of the stator do not do work. In this embodiment, the windings wound on the stator include a winding portion wound on the stator tooth portion, a coil portion located in the stator slot and arranged in parallel along the axial direction of the motor, and a coil portion wound on the stator tooth portion, the coil portion located at the end of the stator does not work due to the winding on the stator tooth portion, and for the first type winding and the second type winding which are wound on the same tooth portion in an overlapping manner to form a double-layer same-core structure, the coil portion located at the end of the stator of the winding arranged in the inner layer is less than the coil portion located at the end of the stator of the winding arranged in the outer layer, so that the power loss of the first type winding of the winding arranged in the inner layer is small, and the maximum time length of the continuous operation is shorter than that of the alternating current power supply due to the power loss, and thus the heat generation. The winding mode of the double-layer concentric structure is adopted, so that the heat dissipation performance of the motor is optimal.

In this embodiment, the electrical connector 3 is a metal wire hooking frame 3. The number of the metal wire hooking frames 3 is two, which are respectively a first metal wire hooking frame and a second metal wire hooking frame. In this embodiment, the two sets of metal wire hooking frames 3 have the same structure, and the structure of the first metal wire hooking frame is described in detail below as an example, referring to fig. 3, the first metal wire hooking frame includes a plate portion 31, and a first connecting portion 32 and a second connecting portion 33 formed at two ends of the plate portion 31 respectively for electrically connecting with the winding 2 and for electrically connecting with the power line 100. The first connecting portion 32 is formed by bending from the plate portion 31, the second connecting portion 33 is tilted outward from the plate portion 31, and a through hole 34 for inserting the power cord 100 is formed on the second connecting portion 33. The two groups of metal wire hooking frames 3 are arranged on the outer side of the stator 1 in a pairwise symmetrical mode along the circumferential direction of the stator 1. In other embodiments, the two groups of metal wire hooking frames 3 can also be asymmetrically arranged on the outer side of the stator 1, and the two groups of metal wire hooking frames 3 are only arranged on the outer side of the stator 1 at a certain angle. In this embodiment, the housing 4 of the dc brushless motor is provided with two insulators 41, the metal wire hooking frame 3 is inserted into the insulators 41, and each insulator 41 is provided with a group of metal wire hooking frames 3. Specifically, a first wire hooking bracket is mounted on one of the insulating members 41, and a second wire hooking bracket is mounted on the other insulating member 41. Each of the insulating members 41 includes a body 411 and three insertion grooves 412 formed on the body 411 for inserting the metal wire hooking frame 3. Two insulators 41 are symmetrically disposed on two sides of the dc brushless motor, respectively, and in the present embodiment, the two insulators 41 are mounted on the outer side of the housing 20. The insulating member 41 and the housing 20 may be assembled as follows: the body 411 of the insulating member 41 is formed with a locking piece 413 protruding outward, and the housing 20 is formed with a locking groove (not shown) engaged with the locking piece 413.

In this embodiment, the metal wire hooking frame 3 is curved, and the shape is smooth due to the design, and the wires are orderly arranged without adhesion, so that in actual work, a plurality of metal wire hooking frames 3 are combined for use, which is convenient for automatic production and manufacture, and meanwhile, the metal wire hooking frame 3 is installed outside the housing 20 through the insulating member 41, thereby shortening the axial dimension of the dc brushless motor.

Referring to fig. 4 and 5, the basic structure of the dc brushless motor shown in the second embodiment is the same as that of the first embodiment, except for the difference between the winding wiring manner and the electrical connection member 5, and the present embodiment adopts the following manner: the first-type windings and the second-type windings are wound on the tooth parts 12 at intervals, namely, only one winding is wound on each tooth part 12, and the windings wound on the adjacent tooth parts 12 are different types of windings. Specifically, a first winding having a first output terminal U1, a fourth winding having two fourth output terminals U2, a third winding having two third output terminals V1, a sixth winding having two sixth output terminals V2, a second winding having two second output terminals W1, and a fifth winding having two fifth output terminals W2 are wound around each of the 6 tooth portions 12 in this order. The electrical connection 5 is a metal insert 5 in this embodiment. The top end of each metal inserting sheet 5 is provided with a hole 51 for connecting with a power line 100, and the tail end of each metal inserting sheet 5 is a circular sheet body connected with the winding in an inserting mode. The metal insert 5 is fixed by arranging a clamping groove (not labeled) on the shell 4 of the direct current brushless motor. The direct-current brushless motor adopting the scheme is convenient for production and manufacturing automation. The number of the metal insertion pieces 5 is set corresponding to the sum of the number of the first-type windings and the number of the second-type windings, that is, in this embodiment, the number of the metal insertion pieces 5 is 6, the 6 metal insertion pieces are divided into two groups, and the two groups of metal insertion pieces 5 are symmetrically arranged on two end faces of the shell 4. 3 metal insertion pieces 5 on every terminal surface evenly arrange and be close to the outer circumference of terminal surface along the circumference of terminal surface on, in other embodiments of this application, two sets of metal insertion pieces 5 also can be asymmetric and form the setting of certain angle on the terminal surface of casing 4.

Referring to fig. 6 and 7, the basic structure of the dc brushless motor shown in the third embodiment is the same as that of the first embodiment except for the winding wiring manner and the electrical connection member 6. The present embodiment adopts the following manner: the plurality of first-type windings are sequentially wound on the adjacent teeth 12 respectively, and the plurality of second-type windings are sequentially wound on the adjacent other teeth 12 respectively, that is, only one winding is wound on each tooth 12, the windings wound on three teeth 12 adjacent in sequence are of the same type, and the windings wound on three teeth 12 adjacent in sequence are of another type. Specifically, a first winding having a first output terminal U1, a second winding having two second output terminals W1, and a third winding having two third output terminals V1 are wound around each of 3 adjacent teeth 12, and a fourth winding having two fourth output terminals U2, a fifth winding having two fifth output terminals W2, and a sixth winding having two sixth output terminals V2 are wound around each of the other 3 adjacent teeth 12.

The electrical connector 6 in this embodiment is a circuit board 6, in particular a flexible circuit board (PCB). In this embodiment, the two circuit boards 6 are a first circuit board and a second circuit board, the first circuit board is electrically connected to the first winding, the second winding and the third winding, and the second circuit board is electrically connected to the fourth winding, the fifth winding and the sixth winding. One end of the circuit board 6 is connected with the plurality of windings in an inserting mode, and the other end of the circuit board is provided with a wiring hole 21 and is connected with the power line 100 through the wiring hole 21. The circuit board 6 is fixed to the outside of the housing 4 by providing a snap assembly (not numbered) on the housing 4 of the dc brushless motor. The first circuit board and the second circuit board are oppositely arranged on two end faces of the shell 4. In order to reduce the unnecessary increase of the axial size of the motor, the circuit board 6 in this embodiment may also be made into a multi-layer board structure, in one embodiment, the circuit board 6 includes a first layer circuit board and a second layer circuit board, the first layer circuit board and the second layer circuit board are electrically isolated from each other, the first layer circuit board is electrically connected with the first winding, the second winding and the third winding respectively, the second layer circuit board is electrically connected with the fourth winding, the fifth winding and the sixth winding respectively, the circuit board 6 is fixed on the outer side of the casing 4 by arranging a fastening component (not numbered) on the casing 4 of the dc brushless motor, and is arranged on one side end face of the casing 4.

It should be noted that the winding wiring manners in the above three embodiments may be replaced with each other. In addition, when 3 types of windings or more than 3 types of windings exist, the number of corresponding metal wire hooking frames, metal inserting pieces and circuit boards can be increased.

In summary, the dc brushless motor of the above embodiment solves the problems of complex connection between the power line connection of the dc brushless motor and the output end of the winding and difficulty in automated manufacturing in the prior art, and by providing at least two sets of electrical connection members in the dc brushless motor, and electrically connecting each electrical connection member with the corresponding winding before electrically connecting to the power line, the wiring process is reduced, thereby improving the manufacturing efficiency and contributing to reducing the cost.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The utility model provides a brushless DC motor, includes to set up to around a central axis pivoted rotor, enclose and establish the stator in the rotor outside and twine a plurality of types of winding on the stator, a plurality of types of winding include a plurality of first type winding and a plurality of second type winding, its characterized in that, brushless DC motor still includes two sets of electric connector, every type the winding corresponds a set of electric connector, every group electric connector earlier with the winding electric connection who corresponds again electric connection in power cord, first type winding is through a set of electric connector is connected with outside first power, the second winding is through another set of electric connector is connected with outside second power.

2. The dc brushless motor of claim 1, wherein the electrical connection members are metal bobbin holders, and two sets of the metal bobbin holders are arranged on an outer side of the stator in a circumferential direction of the stator.

3. The brushless dc motor of claim 2, wherein the two sets of metal wire hooking frames are arranged outside the stator in a symmetrical manner in pairs in a circumferential direction of the stator.

4. The brushless dc motor of claim 2, further comprising a housing enclosing the stator, wherein an insulator is disposed on an outer cylindrical surface of the housing, and wherein the metal bobbin is inserted into the insulator.

5. The dc brushless motor of claim 1, wherein the electrical connectors are metal tabs, the metal tabs are divided into two groups, the number of the metal tabs in each group corresponds to the number of the first type of windings or the number of the second type of windings, and the two groups of metal tabs are respectively disposed on two end faces of the dc brushless motor.

6. The DC brushless motor of claim 5, wherein two sets of the metal inserts are symmetrically disposed on two end faces of the DC brushless motor.

7. The dc brushless motor of claim 1, wherein the electrical connection is a circuit board.

8. The dc brushless motor of claim 7, wherein the circuit boards are a first circuit board and a second circuit board, the first circuit board is electrically connected to the first windings, the second circuit board is electrically connected to the second windings, and the first circuit board and the second circuit board are disposed on two opposite end surfaces of the dc brushless motor.

9. The dc brushless motor of claim 7, wherein the circuit board comprises a first layer circuit and a second layer circuit, electrically isolated from each other, disposed on a side surface of the dc brushless motor, the first layer circuit being connected to the plurality of first type windings, the second layer circuit being electrically connected to the second type windings.

10. The brushless dc motor according to claim 1, wherein the stator includes a ring yoke that surrounds the rotor and has an axis of the central axis, and a plurality of teeth that protrude from the ring yoke in a direction toward the rotor, and the number of the teeth is equal to a sum of the number of the first-type windings and the number of the second-type windings.

11. The dc brushless motor of claim 10, wherein the first type of winding, the second type of winding, and the teeth are arranged in a manner that:

12. The dc brushless motor of claim 10, wherein the first type of winding, the second type of winding, and the teeth are arranged in a manner that: each first type winding and each second type winding are wound on the same tooth part in an overlapping mode, the first type winding is wound on the outer surface of the stator tooth part and is close to the outer surface of the stator tooth part, and the second type winding is wound on the first type winding and is far away from the outer surface of the stator tooth part.

13. The dc brushless motor of claim 12, wherein each winding of the first type of winding has a different number of turns from each winding of the second type of winding, or wherein each winding of the first type of winding has a different wire diameter from each winding of the second type of winding.

14. The dc brushless electric machine of claim 10, wherein the number of the plurality of first type windings is 3, and the number of the plurality of second type windings is 3.

15. The dc brushless motor of claim 1, wherein the first external power source is a dc power source, and the second external power source is an ac power source.