Fan with axial magnetic flux brushless direct current motor

Abstract

The utility model relates to the technical field of fans, in particular to a fan with an axial magnetic flux brushless direct current motor. The fan with the axial magnetic flux brushless direct current motor comprises a fan frame, a stator assembly and a rotor assembly. A connecting column is arranged on the fan frame, a cavity is formed in the connecting column, and a bearing is arranged in the cavity. The stator assembly comprises a control panel and six iron core windings, the control panel is provided with mounting holes, and the mounting holes are formed in the connecting columns in a penetrating mode. The rotor assembly comprises fan blades, a metal sealing cover and permanent magnets, mounting grooves are formed in the fan blades, the permanent magnets comprise two first permanent magnets and two second permanent magnets, and the first permanent magnets and the second permanent magnets are axially magnetized. The metal sealing cover is hermetically connected with the mounting groove; a through hole is formed in the bottom of the mounting groove, and the bearing penetrates through the through hole so that the rotor assembly can rotate relative to the stator assembly. The fan with the axial magnetic flux brushless direct current motor is small in size, high in integration level and capable of reducing loss of magnetic energy and improving working efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of fans, in particular to a fan with an axial magnetic flux brushless DC motor. Background Art

[0002] At present, electric motors have been used to generate kinetic energy in various technical fields. An electric motor (also called an electric machine or an e-motor) is an electrical device configured to convert electrical energy into mechanical energy. The mechanical energy can thereby be used to generate or drive kinetic energy for other devices. An electric motor may generally include a stator and a rotor housed in a motor housing. The stator may be fixed in place and the rotor may move relative to the stator. Commonly, the rotor is rotatably fixed to an axis that rotates with the rotor. Most electric motors generate energy using a magnetic field and winding currents.

[0003] Generally, electric motors can be divided into radial flux motors and axial flux motors. Compared with radial DC motors, axial flux DC motors have the advantages of high power, high torque, simple structure, small size, and light weight. Therefore, axial DC motors are often used in household appliances, electric vehicles, high-voltage power grid equipment, and marine equipment. The fan with axial flux brushless DC motor in the prior art is large in size and low in integration; it is also prone to magnetic leakage, which leads to magnetic energy loss, reduced work efficiency, and increased costs.

[0004] Therefore, it is urgent to design a fan with an axial flux brushless DC motor to solve the above technical problems. Utility Model Content

[0005] The utility model aims to provide a fan with an axial flux brushless DC motor, which has the characteristics of small size and high integration, can reduce the loss of magnetic energy, improve work efficiency and save costs.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides a fan with an axial flux brushless DC motor, comprising:

[0008] A fan frame, wherein a connecting column is provided on the fan frame, a cavity is provided inside the connecting column, and a bearing is provided in the cavity;

[0009] A stator assembly, the stator assembly comprising a control board and six core windings, the control board is provided with a mounting hole, the six core windings are evenly distributed on the control board, and the six core windings are welded to the control board; the mounting hole is penetrated on the connecting column, and one end of the connecting column protrudes from the upper end surface of the core winding;

[0010] A rotor assembly, the rotor assembly comprising a fan blade, a metal sealing cover and a permanent magnet, the fan blade being provided with a mounting groove, the permanent magnet comprising two first permanent magnets and two second permanent magnets, and the first permanent magnets and the second permanent magnets are both axially magnetized, the two first permanent magnets and the two second permanent magnets are both arranged in the mounting groove, and the two first permanent magnets are arranged opposite to each other, and the two second permanent magnets are arranged opposite to each other, along the direction from the stator assembly to the rotor assembly, the magnetic poles of the first permanent magnet and the magnetic poles of the second permanent magnet are opposite, the magnetic poles of the two first permanent magnets are the same, and the magnetic poles of the two second permanent magnets are the same; the metal sealing cover is sealed and connected to the mounting groove; a through hole is provided at the bottom of the mounting groove, and the bearing is penetrated in the through hole so that the rotor assembly can rotate relative to the stator assembly.

[0011] As an optional technical solution for a fan with an axial flux brushless DC motor, the metal sealing cover is provided with an internal thread, the mounting groove is provided with an external thread, and the internal thread and the external thread are screwed together so that the metal sealing cover can seal the mounting groove.

[0012] As an optional technical solution for a fan with an axial flux brushless DC motor, a buckle is provided on the metal sealing cover, a slot is provided on the mounting groove, and the buckle is connected to the slot by a snap connection.

[0013] As an optional technical solution for a fan having an axial flux brushless DC motor, the two first permanent magnets and the two second permanent magnets are both adhesively connected to the bottom wall of the mounting groove.

[0014] As an optional technical solution for a fan with an axial flux brushless DC motor, the rotor assembly also includes a shaft core, one end of the shaft core is connected to the bearing, and the other end of the shaft core is connected to the metal sealing cover.

[0015] As an optional technical solution for a fan with an axial flux brushless DC motor, the fan with an axial flux brushless DC motor further includes a fixing member, and the fixing member is inserted between the control board and the fan frame.

[0016] As an optional technical solution for a fan with an axial flux brushless DC motor, a plurality of air inlets are provided on the fan frame.

[0017] As an optional technical solution for a fan with an axial flux brushless DC motor, the plurality of air inlets are evenly distributed in a ring shape about the axis of the connecting column.

[0018] As an optional technical solution for a fan with an axial flux brushless DC motor, the fan with an axial flux brushless DC motor also includes a shell, a positioning column is provided on one of the shell and the fan frame, a positioning groove is provided on the other of the shell and the fan frame, and the positioning column is plugged into the positioning groove.

[0019] As an optional technical solution for a fan with an axial flux brushless DC motor, the fan frame and the fan blades are both engineering plastic parts, and the metal sealing cover is an iron part.

[0020] The beneficial effects of the utility model include at least:

[0021] The utility model provides a fan with an axial flux brushless DC motor, the fan with an axial flux brushless DC motor comprises a fan frame, a stator assembly and a rotor assembly. A connecting column is provided on the fan frame, a cavity is provided inside the connecting column, and a bearing is provided in the cavity. The stator assembly comprises a control board and six iron core windings, a mounting hole is provided on the control board, the six iron core windings are evenly distributed on the control board, and the six iron core windings are all welded to the control board; the mounting hole is penetrated on the connecting column, and one end of the connecting column protrudes from the upper end surface of the iron core winding. The rotor assembly includes a fan blade, a metal sealing cover and a permanent magnet. The fan blade is provided with a mounting groove. The permanent magnet includes two first permanent magnets and two second permanent magnets, and the first permanent magnets and the second permanent magnets are both axially magnetized. The two first permanent magnets and the two second permanent magnets are both arranged in the mounting groove, and the two first permanent magnets are arranged opposite to each other, and the two second permanent magnets are arranged opposite to each other, along the direction of the stator assembly pointing to the rotor assembly, the magnetic poles of the first permanent magnet and the magnetic poles of the second permanent magnet are opposite, the magnetic poles of the two first permanent magnets are the same, and the magnetic poles of the two second permanent magnets are the same; the metal sealing cover is sealed and connected to the mounting groove; a through hole is opened at the bottom of the mounting groove, and a bearing is penetrated in the through hole so that the rotor assembly can rotate relative to the stator assembly. By setting a connecting column on the fan frame and setting a mounting hole on the control board, the control board is sleeved on the connecting column through the mounting hole, which can improve the stability and reliability of the connection between the stator assembly and the fan frame and avoid relative movement between the two; on the other hand, it can improve the integration of the fan assembly with an axial flux brushless DC motor, so that the fan with an axial flux brushless DC motor is miniaturized, avoiding the problem that the control board is directly connected to the top of the connecting column, resulting in the fan with an axial flux brushless DC motor being too large and not conducive to assembly and use. In addition, the metal sealing cover is sealed and connected to the mounting groove, so that the two first permanent magnets and the two second permanent magnets can be in a relatively closed space, thereby reducing the phenomenon of magnetic leakage during use, reducing the loss of magnetic energy, and shortening the magnetic circuit as much as possible, thereby improving work efficiency and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0023] Figure 1 It is a structural schematic diagram of a fan with an axial flux brushless DC motor provided by an embodiment of the utility model;

[0024] Figure 2 It is an exploded diagram of a fan with an axial flux brushless DC motor provided by an embodiment of the utility model;

[0025] Figure 3 It is a structural schematic diagram of a stator assembly and a fan frame provided in an embodiment of the utility model;

[0026] Figure 4 It is a structural schematic diagram of a stator assembly provided in an embodiment of the utility model;

[0027] Figure 5 It is a schematic structural diagram of a rotor assembly (without showing a metal sealing cover) provided in an embodiment of the utility model.

[0028] Reference numerals

[0029] 100, fan frame; 110, connecting column; 120, cavity; 130, air inlet; 140, positioning column; 150, positioning groove; 200, stator assembly; 210, control board; 2101, mounting hole; 220, iron core winding; 300, rotor assembly; 310, fan blade; 320, metal sealing cover; 330, mounting groove; 340, first permanent magnet; 350, second permanent magnet; 360, shaft core. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0033] In the description of the present utility model, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use. They are only for the convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present utility model, unless otherwise specified, "multiple" means two or more.

[0034] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] In the art, electric motors (motors) within fans can generally be divided into radial flux motors and axial flux motors.

[0038] Among them, the radial flux motor includes a rotor, which is formed by a cylindrical body carrying magnets around its circumference. The stator is regularly configured as a cylindrical hollow body and surrounds the rotor at intervals in the radial direction. The stator usually carries a number of winding elements distributed in the circumferential direction on its inner circumference. Each winding element includes a stator tooth extending radially from the stator yoke toward the rotor. Wires of a metallic, well-conducting material (such as copper) are wound around the stator teeth to form windings. When current is applied to the windings, the rotor attached to the shaft of the motor is subjected to a torque generated by the magnetic field. In a radial flux machine, the magnetic flux generated is radial flux.

[0039] In an axial flux machine, the rotor includes a disc-shaped rotor body having two circular surfaces connected by thickness. The two circular surfaces are generally oriented in opposite axial directions. The disc-shaped rotor body may be defined by an outer edge and an inner circumference, which defines a space acting on the shaft. Typically, at least two permanent magnets are attached to at least one of the two circular surfaces of the rotor body, referred to as an attachment surface. The stator is regularly disc-shaped and arranged in a fixed position spaced axially from the rotor. The stator carries a plurality of winding elements distributed circumferentially on its side facing the rotor. Each winding element includes a corresponding stator tooth extending in an axial direction from the stator yoke toward the rotor. A wire of a metallic, well-conducting material (such as copper) is wound around the stator teeth to form a winding. When current is supplied to the winding, the rotor attached to the shaft of the motor is subjected to a torque generated by the magnetic field. In an axial flux machine, the magnetic flux generated is an axial magnetic flux. The rotor of an axial flux machine can be driven by a stator on one side of the rotor or by two stators on both sides of the rotor. In rotors designed to be driven by a single stator, with a single air gap, a single circular face of the rotor body usually carries a permanent magnet. In two air gap rotors intended to operate with two stators, two circular surfaces usually carry magnets. The magnets are held on the respective circular surfaces by holding means, leaving a space between at least two magnets on the same surface. In both variants, the same magnets can also be held in the rotor body so that they are in flush contact with the two circular surfaces, for example by forming cavities or windows in the rotor body, more specifically in or through the circular surfaces.

[0040] The present embodiment provides a fan with an axial flux brushless DC motor, which has the characteristics of small size and high integration, can reduce the loss of magnetic energy, improve work efficiency and save costs.

[0041] like Figure 1-Figure 5 As shown, the fan with an axial flux brushless DC motor mainly includes a fan frame 100, a stator assembly 200 and a rotor assembly 300. A connecting column 110 is provided on the fan frame 100, a cavity 120 is provided inside the connecting column, and a bearing is provided in the cavity 120. The stator assembly 200 includes a control board 210 and six core windings 220. The control board 210 is provided with mounting holes 2101. The six core windings 220 are evenly distributed on the control board 210, and the six core windings 220 are welded to the control board 210; the mounting hole 2101 is penetrated on the connecting column 110, and one end of the connecting column 110 protrudes from the upper end surface of the core winding 220. The rotor assembly 300 includes a fan blade 310, a metal sealing cover 320 and a permanent magnet. The fan blade 310 is provided with a mounting groove 330. The permanent magnet includes two first permanent magnets 340 and two second permanent magnets 350, and the first permanent magnets 340 and the second permanent magnets 350 are both axially magnetized. The two first permanent magnets 340 and the two second permanent magnets 350 are both arranged in the mounting groove 330, and the two first permanent magnets 340 are arranged opposite to each other, and the two second permanent magnets 350 are arranged opposite to each other, along the direction of the stator assembly 200 pointing to the rotor assembly 300, the magnetic poles of the first permanent magnet 340 and the magnetic poles of the second permanent magnet 350 are opposite, the magnetic poles of the two first permanent magnets 340 are the same, and the magnetic poles of the two second permanent magnets 350 are the same; the metal sealing cover 320 is sealed and connected to the mounting groove 330; a through hole is opened at the bottom of the mounting groove 330, and a bearing is penetrated in the through hole so that the rotor assembly 300 can rotate relative to the stator assembly 200.

[0042] Based on the above design, in this embodiment, a connecting column 110 is provided on the fan frame 100, and a mounting hole 2101 is provided on the control board 210, and the control board 210 is sleeved on the connecting column 110 through the mounting hole 2101, and the control board 210 and the fan frame 100 can be fixedly connected by screws. In this way, on the one hand, the stability and reliability of the connection between the stator assembly 200 and the fan frame 100 can be improved, and relative movement between the two can be avoided; on the other hand, the integration of the fan assembly with an axial flux brushless DC motor can be improved, so that the volume of the fan with an axial flux brushless DC motor is miniaturized, and the problem that the control board 210 is directly connected to the top of the connecting column 110, resulting in the fan with an axial flux brushless DC motor being too large and not conducive to assembly and use, can be avoided.

[0043] It can be understood that, in this embodiment, a cavity 120 is provided inside the connecting column 110, so the connecting column 110 can also be called a middle tube.

[0044] The metal sealing cover 320 in this embodiment is sealed and connected to the mounting groove 330, so that the two first permanent magnets 340 and the two second permanent magnets 350 can be in a relatively sealed space, and then during use, the phenomenon of magnetic leakage can be reduced, the loss of magnetic energy can be reduced, and the magnetic circuit can be shortened as much as possible, thereby improving work efficiency and saving costs. In addition, in order to further reduce the loss of magnetic energy, the air gap between the first permanent magnet 340 and the second permanent magnet 350 and the core winding 220 in this embodiment is reduced as much as possible, thereby improving the working efficiency of the fan with an axial flux brushless DC motor. Exemplarily, the air gap between the first permanent magnet 340 and the second permanent magnet 350 and the core winding 220 can be set to between 0.5mm and 3mm.

[0045] Exemplarily, the fan frame 100 and the fan blades 310 in this embodiment are both engineering plastic parts, thereby reducing the weight of the fan with an axial flux brushless DC motor, making the fan with an axial flux brushless DC motor more lightweight and easier for users to carry and transfer.

[0046] Exemplarily, the metal sealing cover 320 in this embodiment is an iron piece, which can reduce the cost while reducing the magnetic leakage phenomenon.

[0047] It should be noted that the axial magnetization technology of the first permanent magnet 340 and the second permanent magnet 350 in this embodiment belongs to the conventional magnetization technology in the art, so the process steps of axial magnetization are not described in detail in this embodiment. The core winding 220 in this embodiment is set to six, and the permanent magnets include two first permanent magnets 340 and two second permanent magnets 350, so as to form a six-slot four-pole axial flux brushless DC motor solution. Of course, the operator can also design other numbers of core windings 220 and permanent magnets according to actual needs to form other solutions, which will not be described one by one here.

[0048] It is understandable that the core winding 220 and the control board 210 in this embodiment are both components in the prior art, and the control board 210 can control the on / off and strength of the current in the core winding 220, thereby changing the strength of the magnetic field. Therefore, the specific structure and working principle of this embodiment will not be described in detail. The core winding 220 and the control board 210 can be connected by welding to improve the stability of the two.

[0049] The core winding 220 structure in this embodiment is a standard part, and its structure is similar to that of an inductor. Certain types of inductors can be directly used. Its core has good magnetic conductivity and low core loss rate. The copper wires of the core winding 220 are welded at both ends of the bottom of the core. The core needs to be electrically insulated to avoid short circuits between the copper wires and the core. Magnetic fluxes pass through the top and bottom of the core winding 220, and the magnetic fluxes on both sides can be used to drive the rotor assembly 300 to improve work efficiency.

[0050] It can be understood that the main working principle of the fan with an axial flux brushless DC motor in this embodiment is the same as the working principle of common motors on the market, that is, magnetic exchange is carried out through the core winding 220 of the stator assembly 200 and the axially magnetized permanent magnet of the rotor assembly 300, and then the fan blades 310 are driven to rotate by utilizing the generated magnetic force.

[0051] Optionally, the metal sealing cover 320 in this embodiment is provided with an internal thread, and the mounting groove 330 is provided with an external thread, and the internal thread and the external thread are screwed together so that the metal sealing cover 320 can seal the mounting groove 330, thereby improving the stability and reliability of the assembly of the metal sealing cover 320 and the mounting groove 330, and also facilitating the subsequent disassembly and maintenance work of the two.

[0052] Optionally, in some embodiments, a buckle is provided on the metal sealing cover 320, and a slot is provided on the mounting groove 330, and the buckle and the slot are snap-connected, thereby improving the stability and reliability of the assembly of the metal sealing cover 320 and the mounting groove 330, and also facilitating the subsequent disassembly and maintenance of the two.

[0053] Optionally, in some embodiments, the metal sealing cover 320 may also be integrally injection molded with the fan blade 310 to improve stability and reliability.

[0054] Optionally, the two first permanent magnets 340 and the two second permanent magnets 350 in the present embodiment are adhesively connected to the bottom wall of the mounting groove 330, so as to avoid the two first permanent magnets 340 and the two second permanent magnets 350 from shaking and becoming unstable in the mounting groove 330, thereby improving stability and reliability, and further ensuring the stability of the magnetic exchange between the core winding 220 and the first permanent magnet 340 and the second permanent magnet 350, thereby ensuring that the fan blades 310 can rotate smoothly.

[0055] like Figure 5As shown, in this embodiment, the rotor assembly 300 further includes an axis core 360, one end of which is connected to the bearing, and the other end of which is connected to the metal sealing cover 320. The iron core winding 220 of the stator assembly 200 and the axially magnetized permanent magnet of the rotor assembly 300 perform magnetic exchange to realize the rotation of the fan blade 310. The setting of the axis core 360 ​​can support the operation of the fan blade 310, the first permanent magnet 340 and the second permanent magnet 350, and avoid the first permanent magnet 340 and the second permanent magnet 350 from shaking and other unstable phenomena.

[0056] Exemplarily, the shaft core 360 ​​can be made of plastic material or metal material.

[0057] In some embodiments, the fan with an axial flux brushless DC motor further includes a fixing member (not shown in the figure), which is disposed between the control board 210 and the fan frame 100. The setting of the fixing member can improve the stability and reliability of the connection between the control board 210 and the fan frame 100, and prevent the control board 210 from falling off. Optionally, the fixing member in this embodiment can be configured as a buckle or a screw.

[0058] like Figure 2-Figure 3 As shown, in this embodiment, a plurality of air inlets 130 are provided on the fan frame 100, and the plurality of air inlets 130 are evenly distributed in a ring shape about the axis of the connecting column 110, which can improve the uniformity and stability of the air inhaled by the fan (ie, the air intake volume).

[0059] Optionally, a plurality of heat dissipation holes are provided on the fan frame 100 in this embodiment, and the plurality of heat dissipation holes are evenly distributed in a ring shape about the axis of the connecting column 110. This can improve the heat dissipation performance of the fan with an axial flux brushless DC motor, avoid local heat concentration, improve safety, and extend service life.

[0060] The fan with an axial flux brushless DC motor in this embodiment also includes a shell (not shown in the figure), and a positioning column 140 is provided on one of the shell and the fan frame 100, and a positioning groove 150 is provided on the other of the shell and the fan frame 100. The positioning column 140 is plugged into the positioning groove 150, so that the shell and the fan frame 100 can be assembled together, thereby preventing foreign objects from damaging the rotor assembly 300 and the stator assembly 200 during use, thereby extending the service life.

[0061] Obviously, the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

[0062] Note that in the description of this specification, the reference terms "some embodiments", "other embodiments", etc., mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A fan having an axial flux brushless DC motor, characterized in that include: A fan frame (100), wherein a connecting column (110) is provided on the fan frame (100), a cavity (120) is provided inside the connecting column, and a bearing is provided inside the cavity (120); A stator assembly (200), the stator assembly (200) comprising a control board (210) and six iron core windings (220); the control board (210) is provided with a mounting hole (2101); the six iron core windings (220) are evenly distributed on the control board (210), and the six iron core windings (220) are all welded to the control board (210); the mounting hole (2101) is penetrated on the connecting column (110), and one end of the connecting column (110) protrudes from the upper end surface of the iron core winding (220); A rotor assembly (300), the rotor assembly (300) comprising a fan blade (310), a metal sealing cover (320) and a permanent magnet, the fan blade (310) being provided with a mounting groove (330), the permanent magnet comprising two first permanent magnets (340) and two second permanent magnets (350), the first permanent magnets (340) and the second permanent magnets (350) being both axially magnetized, the two first permanent magnets (340) and the two second permanent magnets (350) being both arranged in the mounting groove (330), the two first permanent magnets (340) being arranged opposite to each other, the two second permanent magnets (350) being arranged opposite to each other, The magnets (350) are arranged opposite to each other, along the direction of the stator assembly (200) pointing to the rotor assembly (300); the magnetic poles of the first permanent magnet (340) and the second permanent magnet (350) are opposite to each other, the magnetic poles of the two first permanent magnets (340) are the same, and the magnetic poles of the two second permanent magnets (350) are the same; the metal sealing cover (320) is sealedly connected to the mounting groove (330); a through hole is opened at the bottom of the mounting groove (330), and the bearing is penetrated in the through hole so that the rotor assembly (300) can rotate relative to the stator assembly (200).

2. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The metal sealing cover (320) is provided with an internal thread, and the installation groove (330) is provided with an external thread, and the internal thread and the external thread are threadedly connected so that the metal sealing cover (320) can seal the installation groove (330).

3. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The metal sealing cover (320) is provided with a buckle, the mounting groove (330) is provided with a clamping groove, and the buckle is clamped and connected with the clamping groove.

4. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The two first permanent magnets (340) and the two second permanent magnets (350) are both adhesively connected to the bottom wall of the mounting groove (330).

5. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The rotor assembly (300) further comprises an axis core (360), one end of the axis core (360) being connected to the bearing, and the other end of the axis core (360) being connected to the metal sealing cover (320).

6. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The fan with an axial flux brushless DC motor also includes a fixing member, which is arranged between the control board (210) and the fan frame (100).

7. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The fan frame (100) is provided with a plurality of air inlets (130).

8. The fan with an axial flux brushless DC motor according to claim 7, characterized in that: The plurality of air inlets (130) are evenly distributed in a ring shape about the axis of the connecting column (110).

9. The fan with an axial flux brushless DC motor according to claim 1, characterized in that: The fan with an axial flux brushless DC motor also includes a shell, one of the shell and the fan frame (100) is provided with a positioning column (140), the other of the shell and the fan frame (100) is provided with a positioning groove (150), and the positioning column (140) is plug-connected with the positioning groove (150).

10. A fan with an axial flux brushless DC motor according to any one of claims 1 to 9, characterized in that: The fan frame (100) and the fan blades (310) are both engineering plastic parts, and the metal sealing cover (320) is an iron part.

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