Brushless direct current motor

Abstract

According to the brushless direct current motor provided by the embodiment of the invention, the axial flow heat dissipation piece can guide airflow to pass through the stator assembly under the condition of rotation, so that heat generated by the stator assembly can be exchanged for cooling; a fan blade part and a counterweight heat exchange part are arranged on the axial flow heat dissipation piece, the counterweight heat exchange part can be used as a cooling plate, and a wind body drained from the initial position of the fan blade part can be in contact with the counterweight heat exchange part, so that the wind body is further cooled, and the cooling effect is better when the wind body blows to the stator assembly; the higher the rotating speed of the rotor assembly is, the higher the flow guiding speed of the axial flow heat dissipation piece driven by the rotor assembly is, and the heat exchange efficiency of the stator assembly is better.

Description

Technical Field

[0001] The invention relates to the technical field of brushless DC motors, and in particular to a brushless DC motor. Background Art

[0002] Brushless DC Motor (BLDC) is a high-efficiency motor based on electronic commutation technology. Its core feature is to achieve current commutation through an electronic controller (rather than traditional mechanical brushes) to drive the rotor to rotate. That is, the mechanical brushes and commutators of traditional brushed motors are completely abandoned, and the rotor position is detected through electronic circuits and sensors (such as Hall sensors or encoders), and the current direction of the stator winding is controlled to achieve magnetic field switching; among them, the rotor usually uses permanent magnets (such as neodymium iron boron) to generate a magnetic field, and the stator winding forms an electromagnetic field after power is applied, and the interaction between the two generates torque.

[0003] Existing brushless DC motors are usually used in driving scenarios such as power tools, robot joints, drone propellers, and sweeping robots. However, the temperature inside the motor generally rises quickly, and high temperature causes aging of the winding insulation and shortens its lifespan. Summary of the invention

[0004] An embodiment of the present application provides a brushless DC motor, in which the axial-flow heat sink can guide the airflow through the stator assembly when rotating, so that the stator assembly can generate heat exchange and cooling; the axial-flow heat sink is provided with a fan blade portion and a counterweight heat exchange portion, the counterweight heat exchange portion can be used as a cooling plate, and the wind body guided by the initial position of the fan blade portion can contact the counterweight heat exchange portion, so that the wind body is further cooled, so that when the wind body blows toward the stator assembly, its cooling effect is better; the faster the rotor assembly rotates, the faster the rate at which it drives the axial-flow heat sink to guide the air, and the better the heat exchange efficiency of the stator assembly.

[0005] A brushless DC motor according to an embodiment of the present application includes: A housing, wherein a receiving cavity is provided inside the housing; A stator assembly is arranged inside the housing; A rotor assembly, wherein the rotor assembly is disposed in the housing, the rotor assembly is rotatably connected to the housing, and at least a portion of the rotor assembly passes through a middle portion of the stator assembly; The rotor assembly comprises: An axial flow heat sink, which can guide airflow through the stator assembly when rotating so that the stator assembly can be cooled; The axial flow heat sink comprises: A heat sink body, wherein a through-going mounting shaft hole is provided in the middle of the heat sink body; At least one fan blade portion, the at least one fan blade portion is disposed at at least one end of the heat sink body; A counterweight heat exchange portion is arranged at one end of the heat sink body.

[0006] Furthermore, as a more preferred embodiment of the present invention, the axial-flow heat sink also includes a shoulder abutment portion, which is coaxially connected to one end face of the counterweight heat exchange portion; the adjacent two sides of the at least one wind blade portion are respectively connected to the outer periphery of the shoulder abutment portion and one end of the counterweight heat exchange portion, and the at least one wind blade portion surrounds the shoulder abutment portion; and a guide portion is provided at the connection between the shoulder abutment portion and the counterweight heat exchange portion.

[0007] Further, as a more preferred embodiment of the present invention, The rotor assembly includes a balancing member, the balancing member is arranged at one end of the main body of the rotor assembly, and the axial flow heat sink is arranged at the other end of the main body of the rotor assembly; One end surface of the balancing piece is evenly provided with a laser scale grid, and the balancing piece can be laser cut to remove material to correct the balance of the rotor assembly.

[0008] Further, as a more preferred embodiment of the present invention, the rotor assembly further includes: a rotating shaft, both ends of which extend out of the housing; A magnetic connector, which is sleeved on the rotating shaft and rotates synchronously with the rotating shaft; At least one magnetic member, wherein the at least one magnetic member is embedded in the outer periphery of the magnetic connecting member; A protective cover, wherein both ends of the magnetic connector are detachably connected to the protective cover, and at least a portion of both ends of the at least one magnetic member can be sleeved in the protective cover; The axial flow heat sink is sleeved on one end of the rotating shaft and abuts against one of the protective sleeves; the balancing member is sleeved on the other end of the rotating shaft and abuts against another of the protective sleeves.

[0009] Further, as a more preferred embodiment of the present invention, a magnetic through hole for the rotor assembly to pass through is provided in the middle of the stator assembly; the stator assembly comprises: A stator body, wherein the stator body is equipped with a stator winding; A first bobbin, one end of the stator body being detachably connected to the first bobbin; A second wire frame, the other end of the stator body is detachably connected to the second wire frame.

[0010] Further, as a more preferred embodiment of the present invention, the shell wall of the shell is provided with at least one first deformation portion, the position of the at least one first deformation portion corresponds to that of the first wire frame, and the at least one first deformation portion can be deformed under the action of an external force to press against the outer periphery of the first wire frame; and / or The shell wall of the shell is provided with at least one second deformation part, the position of the at least one second deformation part corresponds to the position of the second wire rack, and the at least one second deformation part can be deformed under the action of external force to press against the outer periphery of the second wire rack.

[0011] Further, as a more preferred embodiment of the present invention, the stator assembly further comprises: a circuit board, the circuit board being electrically connected to the stator winding via a wire; The circuit board is provided with a snap-fitting slot portion, and the first wire rack is provided with a snap-fitting portion adapted to the snap-fitting slot portion, and the snap-fitting portion can be inserted into the snap-fitting slot portion to form a snap-fitting connection; and / or The circuit board is provided with a positioning insertion portion, and the first wire frame is provided with a protrusion matched with the positioning insertion portion, and the end of the protrusion is such that the protrusion can be inserted into the positioning insertion portion.

[0012] Further, as a more preferred embodiment of the present invention, the housing comprises: A shell body, one end of which is provided with an installation window; the installation window is connected to the accommodating cavity; A limiting end cover, wherein the limiting end cover is detachably connected to the installation window; the limiting end cover and the interior of the shell body can clamp the rotor assembly to limit the axial movement of the rotor assembly; The outer wall of the shell is provided with a first exhaust hole, and the first exhaust hole is arranged away from the fan blade part; the wind guided by the fan blade part can flow out from the first exhaust hole; and / or the limiting end cover is provided with at least one hollow part; the fan blade part is arranged away from the limiting end cover, and the wind guided by the fan blade part can flow out from the at least one hollow part.

[0013] Furthermore, as a more preferred embodiment of the present invention, a second exhaust hole is opened on the outer wall of the shell, and a bending portion is formed on the shell wall between the second exhaust hole and the first exhaust hole. The bending portion can be bent and deformed toward the inside of the shell under the action of external force and press against the stator assembly to form a limit for the positioning assembly, and the deformed bending portion can form a slope, which can guide the wind to flow out from the first exhaust hole or the second exhaust hole.

[0014] Further, as a more preferred embodiment of the present invention, the stator assembly further includes: A lead piece, the lead piece is used for electrical connection to an external device; A wire fixing member is arranged in the at least one hollow portion, a limiting slit is arranged in the middle of the wire fixing member, the lead member can pass through the limiting slit, and the lead member is interference fit with the limiting slit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for describing the embodiments are briefly introduced below.

[0016] Figure 1 A schematic diagram of the structure of the brushless DC motor provided in an embodiment of the present application.

[0017] Figure 2 A schematic diagram of the structure of a brushless DC motor provided in an embodiment of the present application.

[0018] Figure 3 A schematic diagram of the half-section structure of the brushless DC motor provided in an embodiment of the present application.

[0019] Figure 4 A schematic diagram of the structure of an axial flow heat sink provided in an embodiment of the present application.

[0020] Figure 5 Another schematic diagram of the structure of the axial flow heat sink provided in an embodiment of the present application.

[0021] Figure 6 A schematic diagram of the structure of the housing provided in an embodiment of the present application.

[0022] Figure 7 A schematic diagram of the structure of the magnetic connector provided in an embodiment of the present application.

[0023] Figure 8 A schematic diagram of the expanded structure of the stator assembly provided in an embodiment of the present application.

[0024] Reference numerals: 1-housing, 11-accommodating cavity, 12-air inlet, 13-first deformation part, 14-second deformation part, 15-housing body, 151-installation window, 16-limiting end cover, 161-annular boss, 162-hollow part, 17-first exhaust hole, 18-second exhaust hole.

[0025] 2-stator assembly, 21-magnetic through hole, 22-stator body, 221-slot, 23-first wire rack, 231-positioning connection protrusion, 232-clamping portion, 233-protruding portion, 24-second wire rack, 25-circuit board, 251-clamping slot portion, 252-positioning insertion portion, 26-bearing, 27-corrugated gasket, 28-lead piece, 29-wire fixing piece, 291-limiting seam.

[0026] 3-rotor assembly, 31-axial flow heat sink, 311-heat sink body, 3111-installation shaft hole, 312-blade part, 313-counterweight heat exchange part, 314-shoulder abutment part, 315-flow guide part, 32-balance part, 33-rotating shaft, 34-magnetic connector, 341-groove, 35-magnetic part, 36-protection kit.

[0027] a-first air gap, b-second air gap. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of this application.

[0029] It should be noted that when an element is referred to as being "fixed on" or "set on" another component, it can be directly on the other component or indirectly set on the other component; when a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component.

[0030] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0032] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0033] Example This embodiment is intended to promote the solution of existing brushless DC motors, which are usually configured in driving scenarios such as power tools, robot joints, drone propellers, and sweeping robots. However, there is a common problem that the temperature inside the motor rises quickly, and the high temperature causes the winding insulation to age and shorten its life. Figures 1 to 8 As shown, this embodiment provides a brushless DC motor, wherein the axial heat sink 31 can guide the airflow through the stator assembly 2 when rotating, so that the stator assembly 2 can generate heat exchange and cooling; the axial heat sink 31 is provided with a fan blade portion 312 and a counterweight heat exchange portion 313, the counterweight heat exchange portion 313 can be used as a cooling plate, and the wind body guided by the initial position of the fan blade portion 312 can contact the counterweight heat exchange portion 313, so that the wind body is further cooled, so that when the wind body blows toward the stator assembly 2, its cooling effect is better; the faster the rotor assembly 3 rotates, the faster the rate at which it drives the axial heat sink 31 to guide the air, and the better the heat exchange efficiency of the stator assembly 2.

[0034] Reference Figures 1 to 3 As shown, the brushless DC motor comprises: a housing 1, a stator assembly 2 and a rotor assembly 3. Among them, a containing cavity 11 is provided inside the housing 1; the stator assembly 2 is provided inside the housing 1; the rotor assembly 3 is provided inside the housing 1, the rotor assembly 3 is rotatably connected to the housing 1, and at least a part of the rotor assembly 3 passes through the middle of the stator assembly 2. It should be supplemented that both ends of the rotor assembly 3 are connected to the housing 1 by a rotating shaft 33 and provided with bearings 26. The spatial layout of the rotor assembly 3 passing through the middle of the stator can be: a magnetic through hole 21 for the rotor assembly 3 to pass through is provided in the middle of the stator assembly 2; the magnetic through hole 21 corresponds to the position of the magnetic region of the rotor assembly 3, and there is a gap between the stator assembly 2 and the rotor assembly 3, that is, the remaining air gap between the inner diameter of the magnetic through hole 21 and the outer diameter of the gradually magnetic region of the rotor, and the air gap is the first air gap a, (such as Figure 3 As shown), the size can be 0.3-0.5mm, and the guiding wind body can pass through for heat exchange.

[0035] Reference Figures 4 and 5As shown, the rotor assembly 3 includes an axial heat sink 31. The axial heat sink 31 can guide the airflow through the stator assembly 2 when rotating, so that the stator assembly 2 can be cooled. For example, aluminum alloy is forged and then CNC machined, and the surface is hard anodized.

[0036] Reference Figures 4 and 5 As shown, the axial flow heat sink 31 includes: a heat sink body 311 , at least one fan blade portion 312 and a counterweight heat exchange portion 313 .

[0037] A through-going mounting shaft hole 3111 is provided in the middle of the heat sink body 311. In some embodiments, a keyway is provided on the inner wall of the mounting shaft hole 3111, and torque is transmitted to the rotating shaft 33 through a flat key.

[0038] At least one fan blade portion 312 is disposed at at least one end of the heat sink body 311; it should be noted that the fan blade portion 312 can be evenly distributed on one end surface of the heat sink body 311. Exemplarily, a circumferential divergent vertical arrangement is adopted, and its thickness is 2 mm. Another exemplary embodiment is that 15 forward-inclined blades are evenly distributed in the circumferential direction, the blade inclination angle is 25°±1°, the root thickness is 1.2 mm, and the end thickness is 0.5 mm.

[0039] Reference Figures 4 and 5 As shown, the counterweight heat exchange part 313 is arranged at one end of the heat sink body 311 or is integrally formed with the heat sink body 311. It should be noted that the counterweight heat exchange part 313 can achieve the dynamic balance and heat dissipation coordination of the rotor assembly 3, wherein, in some embodiments, the entire heat sink body 311 directly adopts copper alloy. The counterweight heat exchange part 313 can be an annular copper alloy insert, which is fixed to the rear end of the heat sink body 311 by laser welding. The exposed surface of the counterweight heat exchange part 313 is a plane, and the exposed surface area of ​​the copper alloy insert is increased, and the heat dissipation is assisted by radiation and convection of the metal material. It should be noted that when the motor is rotating at high speed, that is, when the rotor assembly 3 is rotating at high speed, the airflow driven by the fan blade part will form convection in the housing 1, and the copper alloy insert has good thermal conductivity, which can further assist heat dissipation.

[0040] Reference Figures 4 to 6 As shown, the axial flow heat sink 31 also includes a shoulder abutment portion 314, the diameter of which is smaller than the counterweight heat exchange portion 313, and the shoulder abutment portion 314 is coaxially connected to one end face of the counterweight heat exchange portion 313; the adjacent two sides of at least one fan blade portion 312 are respectively connected to the outer periphery of the shoulder abutment portion 314 and one end of the counterweight heat exchange portion 313, and at least one fan blade portion 312 surrounds the shoulder abutment portion 314; the connection between the shoulder abutment portion 314 and the counterweight heat exchange portion 313 is provided with a guide portion 315. Figure 6As shown, it should be added that the outer shell 1 is evenly distributed with multiple air inlets 12 at positions radially opposite to the guide part 315. After the fan blade part 312 is driven, the wind body is sucked in from the air inlet 12. The direction of the suction will flow through the guide part 315, that is, the streamlined chamfer, which reduces the impact of airflow and improves air intake efficiency.

[0041] Reference Figure 1 As shown, the rotor assembly 3 includes a balancing member 32, which is arranged at one end of the main body of the rotor assembly 3, and an axial heat sink is arranged at the other end of the main body of the rotor assembly 3. Exemplarily, the outer diameter of the balancing member 32 is substantially consistent with the outer diameter of the shoulder abutment portion 314. The inner hole diameter of the balancing member 32 is interference fit with the rotating shaft 33. The balancing member 32 and the axial heat sink are respectively located at the front and rear ends of the rotor assembly 3, thereby forming an axially symmetrical layout to reduce the rotational eccentric force.

[0042] One end surface of the balancing member 32 is evenly provided with a laser scale grid, and the balancing member 32 can be laser cut to remove material to correct the balance of the rotor assembly 3. Each grid unit of the laser scale grid corresponds to a specified mass.

[0043] Reference Figure 1 As shown, the rotor assembly 3 further includes: a rotating shaft 33 , a magnet connecting member 34 , at least one magnetic member 35 and a protective member 36 .

[0044] Both ends of the rotating shaft 33 extend out of the housing 1; The magnetic connector 34 is sleeved on the rotating shaft 33 and rotates synchronously with the rotating shaft 33; it should be supplemented that the magnetic connector 34 can be integrally formed with the rotating shaft 33, or it can transmit torque through a flat key and a keyway, or it can use a shrink-fit process to achieve an interference fit connection.

[0045] Reference Figure 1 and 7 As shown, at least one magnetic component 35 is embedded in the outer periphery of the magnetic connector 34; illustratively, the magnetic connector 34 is a cylinder, and four grooves 341 are respectively provided on the cylinder, and the grooves 341 axially penetrate the entire cylinder. The magnetic component 35 is configured with four pieces, which are respectively matched with the grooves 341. The magnetic component 35 can be a neodymium iron boron magnet, and the surface glue is a high-temperature resistant polyimide glue.

[0046] Reference Figure 1 and 3As shown, the two ends of the magnet connector 34 are detachably connected to the shield 36, and at least a portion of the two ends of at least one magnetic member 35 can be sleeved in the shield 36; that is, the two ends of the magnet are embedded in the inner cavity of the shield 36 to prevent high-speed centrifugal escape. The outer diameter formed by the wind blade part 312 is larger than the outer diameter of the shield 36, that is, the outer diameter of the heat sink body 311 is larger than the outer diameter of the shield 36, forming a stepped airflow diffusion structure to reduce wind resistance. In some embodiments, the shield 36 is a sleeve, which is connected to the two ends of the magnet connector 34 through an internal thread.

[0047] The axial flow heat sink is sleeved on one end of the rotating shaft 33 and abuts against a protective member 36 ; the balancing member 32 is sleeved on the other end of the rotating shaft 33 and abuts against another protective member 36 .

[0048] Reference Figure 1 and 8 As shown, the stator assembly 2 includes: a stator body 22, a first wire frame 23 and a second wire frame 24. Among them, the stator body 22 is installed with a stator winding; one end of the stator body 22 is detachably connected to the first wire frame 23; the other end of the stator body 22 is detachably connected to the second wire frame 24. In some embodiments, both the first wire frame 23 and the second wire frame 24 are provided with positioning connection protrusions 231, and the outer periphery of the stator body 22 is provided with strip grooves 221 adapted to the positioning connection protrusions 231, and the positioning connection protrusions 231 are inserted into the strip grooves 221 to realize the positioning and installation of the first wire frame 23 and the second wire frame 24 on the stator body 22. In some embodiments, the inner side of the wire frame is coated with a 0.1 mm polyimide insulation layer, forming a double insulation barrier with the insulation paper of the winding slots (not shown in the figure) of the stator body 22.

[0049] Reference Figure 1 , 3 As shown in Figures 6 and 7, the shell wall of the shell 1 is provided with at least one first deformation portion 13, the position of at least one first deformation portion 13 corresponds to the position of the first wire frame 23, and at least one first deformation portion 13 can be deformed under the action of external force to press against the outer periphery of the first wire frame 23; and / or the shell wall of the shell 1 is provided with at least one second deformation portion 14, the position of at least one second deformation portion 14 corresponds to the position of the second wire frame 24, and at least one second deformation portion 14 can be deformed under the action of external force to press against the outer periphery of the second wire frame 24. It should be noted that a hydraulic clamp is used to apply a directional load to the deformation portion, so that the metal shell wall undergoes plastic deformation, radially deforms and displaces toward the shell 1, and presses to form a radial locking force on the wire frame, so that a second air gap b is formed between the outer periphery of the stator assembly 2 and the inner wall of the shell 1, thereby increasing the heat exchange area of ​​the stator assembly 2. In some embodiments, the first deformation portion 13 and / or the second deformation portion 14 can be a V-shaped guide groove preset on the inner side.

[0050] Reference Figure 1 and8 As shown, the stator assembly 2 further includes a circuit board 25. In some embodiments, the circuit board 25 is electrically connected to the stator winding via a wire.

[0051] Reference Figure 1 and 8 As shown, the circuit board 25 is provided with a snap-on slot portion 251, and the first wire frame 23 is provided with a snap-on portion 232 adapted to the snap-on slot portion 251, and the snap-on portion 232 can be inserted into the snap-on slot portion 251 to form a snap-on connection; exemplarily, the snap-on slot portion 251 is a dovetail groove structure, and the snap-on portion 232 is an elastic cantilever beam with a barb at the end, which generates elastic deformation after insertion, and the snap-on portion 232 and the first wire frame 23 are integrally injection molded to ensure positioning accuracy.

[0052] Reference Figure 1 and 8 As shown, the circuit board 25 is provided with a positioning insertion portion 252, and the first wire frame 23 is provided with a protrusion 233 adapted to the positioning insertion portion 252, and the end of the protrusion 233 is, and the protrusion 233 can be inserted into the positioning insertion portion 252. Exemplarily, the positioning insertion portion 252 is a rectangular guide hole with rounded corners, and the protrusion 233 is a stepped cylinder, the small end is in clearance with the guide hole, and the root of the large end is provided with an annular stop surface. The positioning insertion portion 252 and the protrusion 233 adopt an asymmetric layout (such as an offset of 1mm or an angle difference of 10°) to prevent reverse connection.

[0053] Reference Figure 1 and 8 As shown, the housing 1 includes: a housing body 15 and a limiting end cover 16 .

[0054] An installation window 151 is disposed at one end of the shell body 15 . The installation window 151 is provided with a stepped annular groove. The installation window 151 is connected to the accommodating cavity 11 .

[0055] The limiting end cover 16 is detachably connected to the installation window 151; the limiting end cover 16 and the interior of the shell body 15 can clamp the rotor assembly 3 to limit the axial movement of the rotor assembly 3; the limiting end cover 16 is an aluminum alloy die-casting, and a central annular boss 161 is provided on the inner side for accommodating the bearing 26 and the corrugated gasket 27. The edge of the installation window 151 is deformed inwardly to engage the limiting end cover 16, and is extruded in the axial direction, cooperating with the corrugated gasket 27 to form axial preload.

[0056] Reference Figure 6As shown, the outer wall of the housing 1 is provided with a first exhaust hole 17, which is arranged away from the fan blade part; the wind body guided by the fan blade part can flow out from the first exhaust hole 17; and / or the limiting end cover 16 is provided with at least one hollow part 162; the fan blade part is arranged away from the limiting end cover 16, and the wind body guided by the fan blade part can flow out from at least one hollow part 162. After the axial airflow of the fan blade part passes through the stator winding, part of the airflow is discharged from the first exhaust hole 17, and the other part is discharged through the hollow part 162, forming a double-path convection.

[0057] Reference Figure 6 As shown, a second exhaust hole 18 is formed on the outer wall of the shell 1, and a bending portion is formed on the shell wall between the second exhaust hole 18 and the first exhaust hole 17. The bending portion can be bent and deformed toward the shell 1 under the action of an external force and press against the stator assembly 2 to form a limit for the positioning assembly, and the deformed bending portion can form a slope, which can guide the wind to flow out from the first exhaust hole 17 or the second exhaust hole 18.

[0058] Reference Figure 1 and 8 As shown, the stator assembly 2 also includes a lead 28 and a wire fixing 29. The lead 28 is used for electrical connection with external devices; the wire fixing is arranged in at least one hollow portion 162, and a limiting slit 291 is arranged in the middle of the wire fixing 29, and the lead 28 can pass through the limiting slit 291, and the lead 28 and the limiting slit 291 are interference fit. The wire fixing 29 can be a silicone body as a whole, and the limiting slit 291 can be a V-shaped slit. The lead 28 includes a Hall signal line, which adopts an asymmetric triangle wiring and has an anti-counterfeiting effect.

[0059] Exemplary brushless DC motor assembly steps: 1. Rotor assembly 3 assembly 1. Attach the magnetic parts 35 to the outer periphery of the magnetic connector 34 according to polarity, apply high temperature resistant polyimide glue, and put them into the protective cover 36 for packaging and fixing.

[0060] 2. The axial flow heat sink is inserted into the front end of the rotating shaft 33, and the balancing member 32 is inserted into the rear end of the rotating shaft 33, and then checked after balancing.

[0061] 3. Bearings 26 are installed at both ends of the rotating shaft 33.

[0062] 2. Assembly of stator assembly 2 1. The first wire frame 23 and the second wire frame 24 are respectively positioned and installed to the two ends of the stator body 22 and connected.

[0063] 2. The circuit board 25 is locked with the first wire frame 23 through a dovetail slot buckle, and the stator body 22 is directly inserted into the ejector pin interface of the circuit board 25 through a gold-plated spring ejector pin.

[0064] 3. Shell 1 and assembly 1. The outer diameter of the axial heat sink 31 is larger than that of the stator assembly 2. The rotor assembly 3 is first installed into the housing 1, and the stator assembly 2 is then pressed into the housing 1. The hydraulic punch squeezes the first deformation part 13 and the second deformation part 14 to limit the radial locking force of the stator assembly 2. 2. The rotating shaft 33 is inserted into the limiting end cover 16, and the edge of the installation window 151 is buckled to squeeze the limiting end cover 16 to achieve axial pre-tightening.

[0065] The electronic device provided by the embodiment of the present application is described in detail above. The principle and implementation method of the present application are described in detail using specific examples herein, and the description of the above embodiments is only used to help understand the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A brushless DC motor, characterized in that: include: A housing, wherein a receiving cavity is provided inside the housing; A stator assembly is arranged inside the housing; A rotor assembly, wherein the rotor assembly is disposed in the housing, the rotor assembly is rotatably connected to the housing, and at least a portion of the rotor assembly passes through a middle portion of the stator assembly; The rotor assembly comprises: An axial flow heat sink, which can guide airflow through the stator assembly when rotating so that the stator assembly can be cooled; The axial flow heat sink comprises: A heat sink body, wherein a through-going mounting shaft hole is provided in the middle of the heat sink body; At least one fan blade portion, the at least one fan blade portion is disposed at at least one end of the heat sink body; A counterweight heat exchange portion is arranged at one end of the heat sink body.

2. The brushless DC motor according to claim 1, characterized in that: The axial-flow heat sink also includes a shoulder abutment portion, which is coaxially connected to an end face of the counterweight heat exchange portion; the adjacent two sides of the at least one wind blade portion are respectively connected to the outer periphery of the shoulder abutment portion and one end of the counterweight heat exchange portion, and the at least one wind blade portion surrounds the shoulder abutment portion; a guide portion is provided at the connection between the shoulder abutment portion and the counterweight heat exchange portion.

3. The brushless DC motor according to claim 1, characterized in that: The rotor assembly comprises a balancing piece, wherein the balancing piece is arranged at one end of a main body of the rotor assembly, and the axial flow heat sink is arranged at the other end of the main body of the rotor assembly.

4. The brushless DC motor according to claim 3, characterized in that: The rotor assembly further comprises: a rotating shaft, both ends of which extend out of the housing; A magnetic connector, which is sleeved on the rotating shaft and rotates synchronously with the rotating shaft; At least one magnetic member, wherein the at least one magnetic member is embedded in the outer periphery of the magnetic connecting member; A protective cover, wherein both ends of the magnetic connector are detachably connected to the protective cover, and at least a portion of both ends of the at least one magnetic member can be sleeved in the protective cover; The fan blade portion is sleeved on one end of the rotating shaft and abuts against one of the protective members; the balancing member is sleeved on the other end of the rotating shaft and abuts against another of the protective members.

5. The brushless DC motor according to claim 1, characterized in that: A magnetic through hole is provided in the middle of the stator assembly for the rotor assembly to pass through; the stator assembly comprises: A stator body, wherein the stator body is equipped with a stator winding; A first bobbin, one end of the stator body being detachably connected to the first bobbin; A second wire frame, the other end of the stator body is detachably connected to the second wire frame.

6. The brushless DC motor according to claim 5, characterized in that: The shell wall of the housing is provided with at least one first deformation portion, the position of the at least one first deformation portion corresponds to the first wire frame, and the at least one first deformation portion can be deformed under the action of an external force to press against the outer periphery of the first wire frame; and / or The shell wall of the shell is provided with at least one second deformation part, the position of the at least one second deformation part corresponds to the position of the second wire rack, and the at least one second deformation part can be deformed under the action of external force to press against the outer periphery of the second wire rack.

7. The brushless DC motor according to claim 5, characterized in that: The stator assembly further includes: a circuit board, the circuit board being electrically connected to the stator winding via a wire; The circuit board is provided with a snap-fitting slot portion, and the first wire rack is provided with a snap-fitting portion adapted to the snap-fitting slot portion, and the snap-fitting portion can be inserted into the snap-fitting slot portion to form a snap-fitting connection; and / or The circuit board is provided with a positioning insertion portion, and the first wire frame is provided with a protrusion matched with the positioning insertion portion, and the end of the protrusion is such that the protrusion can be inserted into the positioning insertion portion.

8. The brushless DC motor according to claim 1, characterized in that: The housing comprises: A shell body, one end of which is provided with an installation window; the installation window is connected to the accommodating cavity; A limiting end cover, wherein the limiting end cover is detachably connected to the installation window; the limiting end cover and the interior of the shell body can clamp the rotor assembly to limit the axial movement of the rotor assembly; The outer wall of the shell is provided with a first exhaust hole, and the first exhaust hole is arranged away from the fan blade part; the wind guided by the fan blade part can flow out from the first exhaust hole; and / or the limiting end cover is provided with at least one hollow part; the fan blade part is arranged away from the limiting end cover, and the wind guided by the fan blade part can flow out from the at least one hollow part.

9. The brushless DC motor according to claim 8, characterized in that: A second exhaust hole is formed on the outer wall of the shell, and a bending portion is formed on the shell wall between the second exhaust hole and the first exhaust hole. The bending portion can be bent and deformed toward the inside of the shell under the action of external force and press against the stator assembly to form a limit for the positioning assembly, and the deformed bending portion can form a slope, which can guide the wind to flow out from the first exhaust hole or the second exhaust hole.

10. The brushless DC motor according to claim 8, characterized in that: The stator assembly further comprises: A lead piece, the lead piece is used for electrical connection to an external device; A wire fixing member is arranged in the at least one hollow portion, a limiting slit is arranged in the middle of the wire fixing member, the lead member can pass through the limiting slit, and the lead member is interference fit with the limiting slit.

Images