Fan and cleaning device

Abstract

The application provides a fan and cleaning equipment, and relates to the technical field of cleaning equipment. The fan comprises a shell, a stator assembly, a rotor assembly, an impeller, a heat conduction structure and a sealing structure. The shell is internally provided with a containing cavity and an airflow channel, the stator assembly is arranged in the containing cavity, the magnetic part of the rotor assembly is opposite to the stator assembly in the axial direction, and the rotating shaft penetrates through the containing cavity and extends into the airflow channel. The impeller is arranged at one end of the rotating shaft, the heat conduction structure is arranged on the side of the stator assembly away from the rotor assembly and is in heat conduction contact with the stator assembly and at least partially exposed to the airflow channel, and the sealing structure is arranged at the position where the rotating shaft penetrates through the containing cavity and is in dynamic sealing cooperation with the rotating shaft. The heat of the stator assembly is transmitted to the airflow channel through the heat conduction structure and is taken away, and the liquid in the airflow channel is intercepted by the sealing structure when entering the containing cavity along the rotating shaft. The axial magnetic flux structure is compressed in the radial direction, the heat conduction structure and the sealing structure are not in conflict with each other in heat dissipation and waterproof, and the fan has the functions of liquid prevention and heat dissipation while the volume is reduced.

Description

Technical Field

[0001] This invention relates to the field of cleaning equipment technology, and more particularly to a fan and cleaning equipment. Background Technology

[0002] The main fan in household cleaning equipment generates the airflow required for operation. In related technologies, the drive motor for such fans often employs a radial flux brushless DC motor with the stator and rotor arranged radially. Because the windings and magnetic circuit of a radial flux motor extend radially, the radial dimension of the motor is relatively large. This makes it difficult to further compress the overall radial profile of the fan, limiting the miniaturization and flattening of cleaning equipment.

[0003] To reduce the radial dimension of the motor, some related technologies also include disc-type stator motors where the windings are supported on a circuit board. These motors are thinner along the axial direction, but their stator, being a circuit board supporting the windings, has low water resistance.

[0004] Household cleaning equipment often operates in humid environments. Wastewater and moisture generated during operation can easily enter the fan. While some technologies aim to waterproof the fan, they often involve adding a labyrinthine water-blocking structure or a waterproof cover to the outside. However, these structures are located in the airflow path, increasing airflow resistance and reducing the fan's aerodynamic efficiency. Furthermore, these structures are ineffective at sealing the rotational gap between the shaft and the housing. Water can still seep into the motor along this gap, adhering to the circuit board supporting the windings and causing short circuits.

[0005] If the cavity housing the motor is completely sealed to prevent water from entering, the heat generated by the circuit board during operation will be trapped inside and unable to dissipate. This heat buildup causes the winding temperature to rise. The magnets opposite the windings will demagnetize due to the increased temperature, causing the motor's output to decrease until it stops.

[0006] Therefore, for fans using circuit board stators, while minimizing size, the two requirements of preventing water from entering along the shaft and dissipating heat from the circuit board are mutually restrictive: open heat dissipation makes waterproofing impossible, while closed waterproofing makes heat dissipation impossible. Consequently, the fan cannot operate reliably and continuously in humid environments. Summary of the Invention

[0007] Therefore, the present invention provides a fan and cleaning equipment, which aims to solve the problem that fans using circuit board stators in related technologies cannot simultaneously achieve the requirements of size, waterproofing and heat dissipation.

[0008] According to a first aspect of the embodiments of this application, a fan is provided, comprising: A housing having a receiving cavity and an airflow channel communicating with the receiving cavity; The stator assembly is disposed within the receiving cavity; A rotor assembly includes a magnetic element and a rotating shaft. The magnetic element is disposed in the receiving cavity. The magnetic element and the stator assembly are disposed opposite each other along the axial direction of the rotating shaft. The rotating shaft is rotatably disposed in the housing. One end of the rotating shaft extends out of the receiving cavity and into the airflow channel. An impeller is disposed at one end of the rotating shaft located in the airflow channel; A heat-conducting structure is disposed on the side of the stator assembly opposite to the rotor assembly and is in thermal contact with the stator assembly, the heat-conducting structure being at least partially exposed in the airflow channel; A sealing structure is provided at the position where the rotating shaft extends out of the receiving cavity and is dynamically sealed with the rotating shaft to prevent liquid in the airflow channel from entering the receiving cavity along the rotating shaft.

[0009] When the fan is running, the stator assembly applies a magnetic field to the axially opposed magnetic components. These magnetic components drive the shaft to rotate around the axis. The end of the shaft that extends into the airflow channel drives the impeller to rotate, generating airflow. The heat generated by the stator assembly during operation is transferred along the side away from the rotor assembly to the heat-conducting structure. The portion of the heat-conducting structure exposed to the airflow channel transfers the heat to the flowing airflow. If liquid entrained in the airflow channel moves along the shaft towards the receiving cavity, it is intercepted by the sealing structure at the point where the shaft exits the cavity. The sealing structure maintains a dynamic seal with the shaft as it rotates, preventing the liquid from entering the receiving cavity. Because the magnetic components and stator assembly are axially opposed and the magnetic field is established axially, the radial dimension of the motor is no longer constrained by the radial expansion of the windings. The axial thickness and radial profile of the fan are compressed, reducing the overall size. The sealing structure only acts at the point where the shaft exits, not occupying the airflow channel. The flow resistance of the airflow channel does not increase due to waterproofing, and the liquid is prevented from entering the receiving cavity, thus preventing the stator assembly from short-circuiting due to liquid ingress. The heat from the stator assembly is directly transferred to the airflow channel through the heat-conducting structure and carried away by the airflow. The heat does not accumulate in the cavity, the temperature rise of the winding is suppressed, and the magnetic components do not demagnetize due to the temperature rise.

[0010] By setting up a heat-conducting structure, the heat of the stator assembly is drawn out to the airflow channel and carried away by the airflow. At the same time, a sealing structure is set up at the position where the shaft passes through the receiving cavity to prevent liquid from entering along the shaft. This allows the sealing required for waterproofing and the heat conduction required for heat dissipation to be achieved simultaneously on the same fan. As a result, the fan can be reduced in size and will not enter liquid, short-circuit, or accumulate heat and lose magnetism in humid environments, thus enabling continuous and reliable operation.

[0011] In one exemplary embodiment of this disclosure, an insert hole is provided on the inner wall of the housing; The heat-conducting structure includes a heat-conducting block embedded in the mounting hole, and the heat-conducting block is sealed to the mounting hole; One side of the heat-conducting block is in thermal contact with the stator assembly, and the other side extends into the airflow channel to form a heat dissipation section.

[0012] By setting a heat-conducting block embedded in the mounting hole of the housing, with one side in thermal contact with the stator assembly and the other side extending into the airflow channel to form a heat dissipation part, the heat of the stator assembly is directly conducted to the airflow channel along the heat-conducting block and carried away by the airflow. At the same time, the heat-conducting block and the mounting hole are sealed together so that the airflow channel and the receiving cavity are not connected at the mounting hole. Thus, the heat dissipation path is short, and heat dissipation and waterproofing do not conflict with each other.

[0013] In one exemplary embodiment of this disclosure, the housing is made of metal; The thermally conductive structure includes a thermally conductive medium filled between the stator assembly and the inner wall of the housing, the thermally conductive medium thermally connecting the stator assembly and the inner wall surface of the housing; At least a portion of the inner wall surface of the housing forms the wall surface of the airflow channel, and this portion of the inner wall surface is exposed in the airflow channel to form a heat dissipation section.

[0014] By filling the space between the stator assembly and the inner wall of the metal housing with a heat-conducting medium, the heat of the stator assembly is transferred to the metal housing through the heat-conducting medium and dissipated into the airflow through the part of the wall that forms the airflow channel. Thus, the housing also serves as a heat dissipation surface, eliminating the need for a separate heat-conducting block, resulting in a simpler structure and a larger heat exchange area.

[0015] In one exemplary embodiment of this disclosure, the surface of the heat dissipation portion exposed to the airflow channel is provided with a plurality of fins at intervals; The extension direction of each fin is parallel to the airflow direction in the airflow channel, and a heat dissipation channel for airflow is formed between two adjacent fins.

[0016] By setting fins whose extension direction is parallel to the airflow direction, the airflow flows through the heat dissipation channels between the fins and continuously exchanges heat with the fin surface. This increases the heat dissipation area while reducing the additional flow resistance, thereby improving the heat dissipation efficiency.

[0017] In one exemplary embodiment of this disclosure, the heat dissipation portion has a plurality of fins on the surface exposed to the airflow channel; The plurality of fins are arranged in a circumferential array along the axis of rotation, and the extension direction of each fin intersects the radial direction of the axis of rotation.

[0018] By arranging fins in a circumferential array along the axis of rotation, the airflow passes over the surface of each fin sequentially as it flows circumferentially within the airflow channel. This results in a longer path for the airflow across the fins, more thorough heat exchange, and further improved heat dissipation efficiency.

[0019] In one exemplary embodiment of this disclosure, the sealing structure includes an elastic seal sleeved on the rotating shaft, and the outer ring of the elastic seal is fixed to the housing; The elastic seal has a sealing lip facing the rotating shaft; the inner diameter of the sealing lip in its natural state is smaller than the outer diameter of the rotating shaft, and the sealing lip abuts against the outer circular surface of the rotating shaft after elastic deformation, and dynamically seals with the rotating shaft.

[0020] By setting an elastic seal with an outer ring fixed to the housing and an inner diameter of the sealing lip smaller than the outer diameter of the shaft in its natural state, the sealing lip continues to abut against the outer surface of the shaft after elastic deformation and maintains sliding contact when the shaft rotates. Thus, the elastic preload of the sealing lip can compensate for assembly tolerances and operational wear, achieving long-term effective dynamic sealing.

[0021] In one exemplary embodiment of this disclosure, the elastic seal is a waterproof gasket; The housing has a sealing groove, and the outer ring of the waterproof gasket is embedded in the sealing groove; The inner lip of the waterproof gasket forms the sealing lip, and the inner lip is interference-fitted with the rotating shaft.

[0022] By embedding the outer ring of the waterproof gasket into the sealing groove of the housing and making the inner lip interfere with the shaft, the inner lip interferes with the outer surface of the shaft to form a dynamic seal when the shaft rotates. This results in a simple structure, convenient assembly, and low cost.

[0023] In one exemplary embodiment of this disclosure, the resilient seal is an oil seal; The oil seal includes a bracket and an elastic sealing lip fixed to the inner side of the bracket; the inner edge of the elastic sealing lip is provided with an elastic ring, which presses the elastic sealing lip against the outer circular surface of the rotating shaft; the bracket is fixed to the housing, and the elastic sealing lip is dynamically sealed to the outer circular surface of the rotating shaft.

[0024] By fixing the oil seal bracket to the housing and tightening the elastic ring of the inner edge of the elastic sealing lip against the outer surface of the shaft, the elastic ring maintains the pressure on the elastic sealing lip when the shaft rotates at high speed. As a result, the oil seal is suitable for high speed and long-term operation, has a long sealing life, and is not prone to leakage under high-speed operation.

[0025] In one exemplary embodiment of this disclosure, the stator assembly includes a PCB board and winding coils; The PCB board has a through hole in the center for the rotating shaft to pass through, and the PCB board is in thermal contact with the heat-conducting structure. The winding coil is disposed on the surface of the PCB board, the winding coil is formed by etching and distributed along the circumference of the PCB board, and the winding coil is opposite to the magnetic component in the axial direction.

[0026] By setting the winding coil to be integrally formed with the PCB board through etching and distributed circumferentially, and forming an axial magnetic flux opposite to the magnetic components in the axial direction, while making the PCB board in thermal contact with the heat-conducting structure, the stator assembly is thinned along the axial direction, the motor is further compressed along the axial direction, and the heat generated by the winding coil is dissipated nearby through the PCB board, so that the heat on the circuit board does not accumulate.

[0027] In one exemplary embodiment of this disclosure, the rotor assembly further includes a connector that forms an axial air gap with the stator assembly; The magnetic elements are arranged circumferentially along the surface of the connector toward the stator assembly, and the magnetic poles of two adjacent magnetic elements alternately oppose each other in the axial direction.

[0028] By setting the connector to support the magnetic components and arranging their magnetic poles alternately in opposite directions circumferentially in the axial direction, an alternating magnetic field is formed in the axial air gap when the rotor assembly rotates. Thus, the connector forms an axial magnetic flux loop for the magnetic components, enhancing the magnetic field in the air gap and making the motor output smooth.

[0029] In one exemplary embodiment of this disclosure, the rotor assembly further includes a bearing assembly disposed in the stator assembly, and the shaft is rotatably supported on the housing via the bearing assembly.

[0030] By placing the bearing assembly within the stator assembly and supporting the shaft on the housing via the bearing assembly, the support position of the shaft is located within the stator region. This results in smooth shaft rotation and minimal wear. Furthermore, the bearing assembly occupies the axial space of the stator assembly without increasing the axial dimension of the fan.

[0031] In one exemplary embodiment of this disclosure, the housing is provided with an axial positioning surface, which is formed by a stepped surface on the inner wall of the housing; One side of the bearing assembly abuts against the shoulder of the rotating shaft, and the other side abuts against the axial positioning surface, thereby defining the axial air gap formed between the magnetic element and the stator assembly.

[0032] By setting a stepped surface on the inner wall of the housing to form an axial positioning surface, one side of the bearing assembly is abutted by the shoulder of the shaft and the other side is abutted by the axial positioning surface. In this way, the axial position of the shaft relative to the housing is fixed, the axial air gap between the magnetic component and the stator assembly is fixed after assembly and does not drift during operation, and the motor output is stable.

[0033] In one exemplary embodiment of this disclosure, the fan further includes a support member, the support member having a central hole through which the rotating shaft passes; The inner wall of the support member is provided with a bearing seat for supporting the bearing assembly; the support member is fixedly connected to the housing, and the rotor assembly is axially constrained between the support member and the housing.

[0034] By setting up a support member to support the bearing assembly via the bearing seat and fix it to the housing, the rotor assembly is clamped and positioned by the support member and the housing from both sides of the axial direction, thus ensuring a stable assembly. Furthermore, the support member and the housing can be processed separately and then fixedly connected, which facilitates the installation of the rotor assembly and axial constraint.

[0035] In one exemplary embodiment of this disclosure, the sealing structure is disposed axially between the impeller and the bearing assembly; The sealing structure has a gap along the axial direction between itself and the impeller, and / or the sealing structure has a gap along the axial direction between itself and the bearing assembly, so as to isolate the receiving cavity from the airflow passage in the axial direction.

[0036] By axially positioning the sealing structure between the impeller and the bearing assembly, and leaving an axial gap between the sealing structure and the impeller and / or between the sealing structure and the bearing assembly, the liquid on the airflow channel side is intercepted as it moves along the shaft toward the receiving cavity. Thus, the bearing assembly and the stator assembly are protected simultaneously, and the gap prevents liquid or airflow from interfering with each other.

[0037] According to a second aspect of the embodiments of this application, a cleaning device is provided, comprising: Equipment body; The fan as described in any one of the first aspects is disposed on the equipment body.

[0038] By incorporating the aforementioned fan into the main body of the cleaning equipment, when the cleaning equipment operates in a humid environment, wastewater and water vapor are blocked from the containment cavity by the fan's sealing structure, while the heat from the fan stator assembly is discharged through the airflow channel via the heat-conducting structure. As a result, the entire cleaning equipment tends to be miniaturized and flattened due to the compression of the fan's axial and radial dimensions, and it does not experience liquid ingress, short circuits, heat accumulation, or demagnetization in a humid environment, thus improving operational reliability.

[0039] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0040] The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0041] Figure 1 This is a cross-sectional view of the fan according to an embodiment of the present invention; Figure 2This is a partial cross-sectional view of a fan in an embodiment of the present invention, wherein the elastic sealing element is a waterproof gasket; Figure 3 This is a partial cross-sectional view of a fan in an embodiment of the present invention, where the elastic seal is an oil seal.

[0042] Explanation of reference numerals in the attached figures 100. Shell; 110. Receiving cavity; 120. Airflow channel; 200. Stator assembly; 300. Rotor assembly; 310. Magnetic component; 320. Shaft; 330. Connecting component; 400. Impeller; 410. Blade; 500. Thermally conductive structure; 600. Sealing structure; 610. Elastic seal; 611. Sealing lip; 612. Waterproof gasket; 613. Oil seal; 700. Bearing assembly; 800. Support components. Detailed Implementation

[0043] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0044] The features, structures, or characteristics described above can be combined in any suitable manner in one or more embodiments, and the features discussed in the various embodiments are interchangeable where possible. In the above description, numerous specific details are provided to give a full understanding of embodiments of the invention. However, those skilled in the art will recognize that the technical solutions of the invention can be practiced without one or more of the specific details, or other methods, components, materials, etc., can be employed. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the invention.

[0045] Although relative terms such as "up" and "down" are used in this invention to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples in the accompanying drawings. It is understood that if the icon's arrangement is flipped so that it is upside down, the component described as "up" will become the component described as "down". Other relative terms such as "high", "low", "top", "bottom", "front", "back", "left", and "right" also have similar meanings. When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0046] In this invention, the terms “a,” “an,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “comprising,” “including,” and “having” are used to indicate an open-ended inclusion meaning and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.

[0047] refer to Figures 1 to 3 As shown in the figure, this application provides a fan. The fan includes a housing 100, a stator assembly 200, a rotor assembly 300, an impeller 400, a heat-conducting structure 500, and a sealing structure 600.

[0048] A receiving cavity 110 and an airflow channel 120 are formed within the housing 100. The receiving cavity 110 is connected to the airflow channel 120. The stator assembly 200 is received within the receiving cavity 110. The rotor assembly 300 includes a magnetic element 310 and a rotating shaft 320. The magnetic element 310 is located within the receiving cavity 110. The magnetic element 310 and the stator assembly 200 are arranged opposite each other along the axial direction of the rotating shaft 320. The rotating shaft 320 is rotatably disposed within the housing 100. One end of the rotating shaft 320 extends out of the receiving cavity 110 and into the airflow channel 120. An impeller 400 is mounted on the end of the rotating shaft 320 that extends into the airflow channel 120. A heat-conducting structure 500 is located on the side of the stator assembly 200 opposite to the rotor assembly 300. The heat-conducting structure 500 is in thermal contact with the stator assembly 200. At least a portion of the heat-conducting structure 500 is exposed to the airflow channel 120. The sealing structure 600 is located at the position where the rotating shaft 320 protrudes from the receiving cavity 110. The sealing structure 600 is dynamically sealed with the rotating shaft 320.

[0049] When the fan is operating, the stator assembly 200 applies an axial magnetic field force to the magnetic component 310. The magnetic component 310 drives the shaft 320 to rotate around its axis. The shaft 320 drives the impeller 400 to rotate within the airflow channel 120. The rotation of the impeller 400 generates airflow, which flows through the airflow channel 120. The heat generated by the stator assembly 200 is transferred to the airflow channel 120 via the heat-conducting structure 500 and carried away by the flowing air. As the liquid entrained in the airflow channel 120 moves along the shaft 320 towards the receiving cavity 110, it is intercepted by the sealing structure 600 at the point where the shaft 320 exits the receiving cavity 110.

[0050] By arranging the magnetic component 310 and the stator assembly 200 axially opposite each other, the sealing structure 600 dynamically sealing at the point where the shaft 320 passes through, and the heat-conducting structure 500 drawing the heat of the stator assembly 200 to the airflow channel 120, the radial dimension of the motor is no longer constrained by the radial stacking and can be compressed. The liquid is intercepted by the sealing structure 600 before reaching the receiving cavity 110, and the heat generated by the stator assembly 200 is carried away by the airflow at the point of generation. Thus, waterproofing and heat dissipation are achieved simultaneously on the same fan without conflict. The fan has both liquid-proof and heat dissipation capabilities while reducing its size.

[0051] The division between the receiving cavity 110 and the airflow channel 120 is based on the location of the rotor assembly 300 and the impeller 400. The space where the rotor assembly 300 is located constitutes the receiving cavity 110, and the space where the impeller 400 is located constitutes the airflow channel 120. The airflow channel 120 has an air inlet and an air outlet.

[0052] In some embodiments, the airflow channel 120 is a volute-shaped flow channel that gradually expands circumferentially along the impeller 400 and leads to the air outlet. The air inlet is axially aligned with the center of the impeller 400, and the air outlet is tangentially led out circumferentially along the impeller 400. When the impeller 400 rotates, the airflow enters axially from the air inlet, is radially thrown into the volute-shaped airflow channel 120 by the impeller 400, and is discharged from the air outlet after circumferential convergence. The volute-shaped airflow channel 120 gradually converts the dynamic pressure of the airflow thrown out by the impeller 400 into static pressure, improving the aerodynamic efficiency of the fan. The heat dissipation part of the heat-conducting structure 500 exposed in the airflow channel 120 is located on the wall surface through which the airflow flows, allowing the flowing airflow to sweep over the heat dissipation part and carry away heat during its convergence and discharge.

[0053] In some embodiments, a protective net is provided at the air inlet of the airflow channel 120. The protective net prevents large foreign objects from entering the airflow channel 120 with the airflow and colliding with the impeller 400, thus avoiding damage to the impeller 400 or jamming of the shaft 320 by foreign objects.

[0054] In some implementations, the impeller 400 rotates at a speed of 20krpm to 100krpm during operation. Higher speeds result in greater output air pressure and volume, but also increase the load on the impeller 400 and shaft 320, as well as the heat generated by the winding coils. When higher air pressure and volume are required, the fan operates at a higher speed, necessitating that the heat dissipation of the heat-conducting structure 500 and the dynamic seal of the sealing structure 600 be adapted to the higher operating temperature and speed. Conversely, when lower noise and power consumption are required, the fan operates at a lower speed.

[0055] The stator assembly 200 is a stator structure that carries the windings. The side of the stator assembly 200 facing away from the rotor assembly 300 is in thermal contact with the heat-conducting structure 500. When the stator assembly 200 is energized, a magnetic field is formed circumferentially on the side facing the magnetic element 310. This magnetic field acts on the magnetic element 310 axially.

[0056] In some embodiments, the windings of the stator assembly 200 are supported on a substrate, the windings being distributed circumferentially along the substrate and axially aligned with the magnetic element 310, thereby forming an axial flux structure that establishes magnetic flux along the axial direction. The substrate may be a printed circuit board.

[0057] In other embodiments, the winding of the stator assembly 200 is a wound coil, with multiple wound coils arranged circumferentially and fixed on an insulated winding support. The side of the winding support opposite to the magnetic component 310 is in thermal contact with the heat-conducting structure 500.

[0058] In some other embodiments, the stator assembly 200 further includes an axially oriented stator core, with windings wound around the stator core, which guides magnetic flux axially. In all the aforementioned forms of the stator assembly 200, the windings are axially aligned with the magnetic element 310, forming an axial magnetic flux structure, and the side facing away from the magnetic element 310 is in thermal contact with the heat-conducting structure 500. It is understood that the winding bearing form of the stator assembly 200 is not limited to the above-mentioned types; as long as the windings are axially aligned with the magnetic element 310, this application does not limit the specific form of the winding bearing in the stator assembly 200.

[0059] In some embodiments, the magnetic component 310 is a permanent magnet, which has low cost and high stability. In other embodiments, the magnetic component 310 is a sintered NdFeB magnet, which has a high magnetic energy product, making it easier to establish a strong magnetic field in the axial air gap. In still other embodiments, the magnetic component 310 is a ferrite magnet, which has good temperature resistance and low cost. Permanent magnets have a demagnetization temperature. When the temperature of the magnetic component 310 exceeds its demagnetization temperature, the magnetic component 310 undergoes irreversible demagnetization, and the magnetic field weakens. If the heat generated during the operation of the stator assembly 200 accumulates and is transferred to the magnetic component 310, it will cause the magnetic component 310 to heat up. The heat-conducting structure 500 dissipates the heat of the stator assembly 200 through the airflow channel 120, suppressing the temperature rise within the receiving cavity 110 and keeping the operating temperature of the magnetic component 310 below its demagnetization temperature. Specifically, the magnetic components 310 are arranged circumferentially on the side of the rotor assembly 300 facing the stator assembly 200 to cooperate with the magnetic field generated by the stator assembly 200 and to avoid local overheating.

[0060] The rotating shaft 320 is an elongated shaft-shaped component. The rotating shaft 320 extends axially and is rotatably mounted on the housing 100. One end of the rotating shaft 320 is located within the receiving cavity 110 and connected to the magnetic element 310, while the other end of the rotating shaft 320 extends out of the receiving cavity 110 and into the airflow channel 120. The portion of the rotating shaft 320 extending out of the receiving cavity 110 is located within the airflow channel 120 and may come into contact with liquid within the airflow channel 120.

[0061] In some embodiments, the shaft 320 is a stainless steel shaft, or the surface of the shaft 320 is provided with an anti-rust coating to withstand the humid environment within the airflow channel 120. When the magnetic component 310 is driven to rotate by the magnetic field of the stator assembly 200, it drives the shaft 320 to rotate together.

[0062] Impeller 400 is a component that generates airflow. Impeller 400 is mounted on one end of shaft 320 that extends into airflow channel 120. Impeller 400 rotates with shaft 320. Impeller 400 is located within airflow channel 120.

[0063] In some embodiments, the impeller 400 is a centrifugal impeller, which, when rotating, redirects axially incoming airflow to radially outgoing airflow. The impeller 400 includes a hub and a plurality of blades 410 arranged circumferentially from the hub. The hub is fitted and fixed to the shaft 320. In some embodiments, the number of blades 410 is 7 to 13, with guide channels formed between adjacent blades 410. A greater number of blades 410 results in more effective airflow guidance, but also narrower channels and greater flow resistance. A larger number of blades 410 is used when higher air pressure is required; a smaller number is used when higher airflow is required. It is understood that the impeller 400 can also be an axial-flow impeller or a mixed-flow impeller; this application does not limit the specific form of the impeller 400.

[0064] A portion of the heat-conducting structure 500 is in thermal contact with the stator assembly 200. Another portion of the heat-conducting structure 500 is exposed to the airflow channel 120. Heat generated during operation of the stator assembly 200 is transferred to the heat-conducting structure 500 via its side facing away from the rotor assembly 300. The heat is conducted along the heat-conducting structure 500 to the portion exposed to the airflow channel 120. The airflow through the airflow channel 120 carries away the heat from this portion. Thus, the heat from the stator assembly 200 is discharged to the airflow channel 120 along a heat-conducting path independent of the main flow path of the airflow channel 120, without accumulating within the receiving cavity 110.

[0065] The sealing structure 600 is designed to block liquid. A rotational gap exists between the rotating shaft 320 and the housing 100 where the shaft 320 extends out of the receiving cavity 110. The sealing structure 600 fills this rotational gap and dynamically seals with the shaft 320. The dynamic seal means that the sealing structure 600 maintains its sealing of this rotational gap even when the shaft 320 is rotating. Liquid in the airflow channel 120 may migrate along the shaft 320 towards the receiving cavity 110 when the fan is operating. The sealing structure 600 blocks the liquid at the point where the shaft 320 extends out of the receiving cavity 110, preventing liquid from entering the receiving cavity 110.

[0066] In some embodiments, the windings of the stator assembly 200 are electrically connected to the drive circuit. The drive circuit energizes each phase winding of the stator assembly 200 in a predetermined commutation sequence. After the fan is connected to the power supply, the windings of the stator assembly 200 are energized. The windings establish a magnetic field in the axial direction. This magnetic field acts on the magnetic component 310. The magnetic component 310 is subjected to force and rotates circumferentially. As the magnetic component 310 rotates through a certain angle, the drive circuit switches the energized winding phase, causing the magnetic field established by the winding to advance circumferentially, continuously attracting the magnetic component 310 to rotate in the same direction. The magnetic component 310 drives the rotating shaft 320 to rotate. The rotating shaft 320 drives the impeller 400 located in the airflow channel 120 to rotate. The rotation of the impeller 400 causes airflow to enter from the air inlet of the airflow channel 120 and exit from the air outlet, forming the output airflow of the fan. During this process, the windings of the stator assembly 200 heat up due to energization. The heat is transferred from the side of the stator assembly 200 away from the rotor assembly 300 to the heat-conducting structure 500, and then carried away by the airflow from the part of the heat-conducting structure 500 exposed to the airflow channel 120. At the same time, if the liquid entrained by the airflow in the airflow channel 120 migrates along the rotating shaft 320 towards the receiving cavity 110, it will be intercepted by the sealing structure 600 at the position where the rotating shaft 320 exits the receiving cavity 110, and cannot enter the receiving cavity 110.

[0067] The aforementioned fan, through the axially opposite arrangement of the magnetic component 310 and the stator assembly 200, establishes the motor's magnetic field along the axial direction. The radial dimension of the motor is no longer constrained by the radial expansion of the windings. The fan's axial thickness decreases, its radial profile shrinks, and the overall volume is compressed. The sealing structure 600 only acts on the position where the shaft 320 protrudes from the receiving cavity 110, and does not occupy the airflow channel 120. The flow resistance of the airflow channel 120 is not increased by the sealing. Liquid is blocked outside the receiving cavity 110 by the sealing structure 600, preventing the stator assembly 200 from short-circuiting due to liquid intrusion. Heat from the stator assembly 200 is directly transferred to the airflow channel 120 via the heat-conducting structure 500 and carried away by the airflow. Heat does not accumulate within the sealed receiving cavity 110. The temperature rise of the stator assembly 200's windings is suppressed. The magnetic component 310, axially opposite to the windings, does not demagnetize due to temperature rise. Therefore, the requirement for waterproofing—sealing of the containment cavity 110—and the requirement for heat dissipation—thermal conduction are simultaneously achieved on the same fan. While reducing its size, the fan avoids liquid ingress and short circuits, as well as heat accumulation and demagnetization, in humid environments, ensuring continuous and reliable operation.

[0068] In some embodiments, the housing 100 is made of a non-metallic material. For example, the lower housing of the housing 100 is injection molded from plastic. Plastic has low thermal conductivity, and heat from the stator assembly 200 is not easily dissipated through the lower plastic housing. Therefore, an insert hole is provided in the wall of the lower housing. The heat-conducting structure 500 includes a heat-conducting block embedded in the insert hole. The heat-conducting block is a solid block with a thermal conductivity higher than that of the housing 100.

[0069] In some embodiments, the heat-conducting block is made of aluminum or copper. In other embodiments, the heat-conducting block is made of graphite or ceramic thermally conductive material.

[0070] A sealed connection is formed between the heat-conducting block and the wall of the mounting hole. This sealed connection can be an interference fit between the heat-conducting block and the mounting hole, or it can be achieved by filling the space between the heat-conducting block and the hole wall with sealant, or by placing a sealing ring between the heat-conducting block and the hole wall. After the heat-conducting block and the mounting hole are sealed, the airflow channel 120 and the receiving cavity 110 are not connected at the mounting hole, and liquid or airflow does not flow between them through the mounting hole.

[0071] One side of the heat-conducting block makes thermal contact with the stator assembly 200. This side can be directly attached to the stator assembly 200, or thermally conductive adhesive or a thermally conductive pad can be filled between them to eliminate contact gaps. The other side of the heat-conducting block extends into the airflow channel 120 to form a heat dissipation section. The heat dissipation section is exposed to the airflow flowing within the airflow channel 120.

[0072] In some embodiments, the axial thickness of the heat-conducting block is adapted to the wall thickness of the lower housing, such that the side of the heat-conducting block that contacts the stator assembly 200 is located within the receiving cavity 110, and the side that extends into the airflow channel 120 is located within the airflow channel 120. A pre-compression can be applied between the heat-conducting block and the stator assembly 200 by an elastic element to maintain contact pressure between their contact surfaces, thereby reducing the contact thermal resistance of the contact surfaces.

[0073] In some embodiments, a thermally conductive medium is filled between the heat-conducting block and the mating surface of the stator assembly 200 to fill the microscopic gaps in the mating surface. Heat from the stator assembly 200 is transferred through the side of the heat-conducting block that contacts the stator assembly 200, and conducted along the heat-conducting block to the heat dissipation portion extending into the airflow channel 120, where it is carried away by the airflow. The heat-conducting block spans the lower housing with low thermal conductivity, directly delivering the heat from the stator assembly 200 into the airflow channel 120.

[0074] By setting a heat-conducting block embedded in the mounting hole of the housing 100, with one side of it in thermal contact with the stator assembly 200 and the other side extending into the airflow channel 120 to form a heat dissipation part, the heat of the stator assembly 200 is directly conducted to the airflow channel 120 along the heat-conducting block and carried away by the airflow. At the same time, the heat-conducting block and the mounting hole are sealed together so that the airflow channel 120 and the receiving cavity 110 are not connected at the mounting hole. Thus, the heat dissipation path is short, and heat dissipation and waterproofing do not conflict with each other.

[0075] In other embodiments, the housing 100 is made of metal. For example, the housing 100 is die-cast from an aluminum alloy or a magnesium alloy. The metallic housing 100 itself has high thermal conductivity. In this case, the thermally conductive structure 500 includes a thermally conductive medium filled between the stator assembly 200 and the inner wall of the housing 100. The thermally conductive medium is a thermally conductive material that can fill the gap.

[0076] In some embodiments, the thermally conductive medium is a thermally conductive adhesive. In other embodiments, the thermally conductive medium is a thermally conductive silicone grease or a phase change thermal pad.

[0077] A thermally conductive medium fills the gap between the side of the stator assembly 200 facing away from the rotor assembly 300 and the inner wall of the housing 100. The thermally conductive medium thermally connects the stator assembly 200 to the inner wall surface of the housing 100. At least a portion of the inner wall surface of the housing 100 forms the wall surface of the airflow channel 120. This portion of the inner wall surface is exposed in the airflow channel 120 to form a heat dissipation section.

[0078] In some embodiments, the area corresponding to the wall of the housing 100 that constitutes the heat dissipation part is provided with heat dissipation protrusions or fins that protrude from the wall on the side facing the airflow channel 120, so as to increase the heat exchange area between the area and the airflow.

[0079] In some embodiments, the metal housing 100 is made of aluminum alloy or magnesium alloy, balancing thermal conductivity and lightweight. Heat from the stator assembly 200 is transferred to the metal housing 100 via a heat-conducting medium, diffuses along the housing 100 to the heat dissipation section forming the wall of the airflow channel 120, and is carried away by the airflow passing through this wall. The lateral thermal diffusion of the housing 100 itself causes heat to spread along the housing 100 before reaching the heat dissipation section, resulting in an effective heat dissipation area larger than the projected area of ​​the stator assembly 200. The heat-conducting medium fills the gap between the stator assembly 200 and the inner wall of the housing 100, eliminating contact thermal resistance between them. The metal housing 100 also serves as a heat dissipation surface. In this case, there is no need for a separate heat-conducting block extending into the airflow channel 120, resulting in a simple structure. The heat dissipation section is the wall of the airflow channel 120, providing a large heat exchange area.

[0080] By filling the space between the stator assembly 200 and the inner wall of the metal housing 100 with a heat-conducting medium, the heat of the stator assembly 200 is transferred to the metal housing 100 through the heat-conducting medium and dissipated into the airflow through the part of the wall forming the airflow channel 120. Thus, the housing 100 also serves as a heat dissipation surface, eliminating the need for a separate heat-conducting block, resulting in a simpler structure and a larger heat exchange area.

[0081] Regardless of whether the heat-conducting structure 500 uses a heat-conducting block or a heat-conducting medium, fins can be further provided on the surface of the heat dissipation part exposed to the airflow channel 120 to increase the heat exchange area. Two fin arrangement methods are described below.

[0082] In some embodiments, the surface of the heat dissipation unit exposed to the airflow channel 120 is provided with multiple fins at intervals. Each fin is a sheet-like structure protruding from the surface of the heat dissipation unit. The multiple fins are spaced apart from each other. The extending direction of each fin is parallel to the airflow direction within the airflow channel 120. A heat dissipation channel for airflow is formed between two adjacent fins.

[0083] In some implementations, the number of fins ranges from 4 to 20. More fins result in a larger heat exchange area, but also narrower heat dissipation channels between adjacent fins and greater flow resistance. For applications requiring high heat dissipation, a larger number of fins with smaller spacing are used; conversely, for applications requiring high flow resistance, a smaller number of fins with larger spacing are used.

[0084] In some embodiments, the fins protrude from the surface of the heat dissipation section at a height of 2mm to 8mm, and the spacing between adjacent fins is 1mm to 3mm. Higher fins and smaller spacing result in a larger heat dissipation area; however, if the spacing is too small, the heat dissipation channel between adjacent fins is easily filled by the boundary layer of the airflow, and the heat exchange efficiency no longer increases with decreasing spacing. After the airflow enters the airflow channel 120, it flows through the space between adjacent fins along the heat dissipation channel parallel to the fin extension direction, continuously exchanging heat with the fin surface. The fins increase the contact area between the heat dissipation section and the airflow, removing more heat per unit time. Based on the exposed area of ​​the heat dissipation section, the heat exchange area between the heat dissipation section and the airflow can be increased to 3 to 6 times that without fins after the fins are installed. Under the same airflow rate, the heat dissipation section with fins can reduce the steady-state temperature rise of the stator assembly 200 compared to the case without fins. The extension direction of the fins is parallel to the airflow direction, and the airflow flows along the fins, resulting in a smaller additional flow resistance while increasing the heat exchange area.

[0085] By setting fins whose extension direction is parallel to the airflow direction, the airflow flows through the heat dissipation channels between the fins and continuously exchanges heat with the fin surface. This increases the heat dissipation area while reducing the additional flow resistance, thereby improving the heat dissipation efficiency.

[0086] In other embodiments, the heat dissipation section has multiple fins on the surface exposed to the airflow channel 120. The fins are arranged in a circumferential array along the rotation axis 320. The extension direction of each fin intersects the radial direction of the rotation axis 320. In some embodiments, the angle between the extension direction of the fin and the radial direction of the rotation axis 320 is 15° to 60°. The closer this angle is to the flow tangent direction of the airflow at that location, the smoother the airflow passes over the fins. In some embodiments, the number of fins arranged in the circumferential array is 12 to 36, with adjacent fins evenly spaced circumferentially. The extension direction of each fin is inclined along the circumferential flow tangent direction of the airflow at that location, allowing the airflow to pass between adjacent fins along the inclined direction of the fins. As the airflow flows circumferentially within the airflow channel 120, it sequentially passes over the fins arranged in the circumferential array, exchanging heat with the fin surfaces. The fins are distributed in a circumferential array along the rotation axis 320, adapting to the direction of the circumferential airflow within the airflow channel 120. The airflow travels a longer path across the fins, resulting in more thorough heat exchange. Compared to radially arranged fins, this method better aligns with circumferential airflow, further improving heat dissipation efficiency. It is understood that the choice between fins arranged parallel to the airflow direction and fins arranged in a circumferential array can be made based on the actual airflow direction within the airflow channel 120; this application does not limit the fin arrangement direction.

[0087] By setting fins arranged in a circumferential array along the rotation axis 320, the airflow passes over the surface of each fin sequentially when flowing circumferentially in the airflow channel 120. As a result, the path of the airflow passing over the fins is longer, the heat exchange is more thorough, and the heat dissipation efficiency is further improved.

[0088] In some implementations, reference Figures 1 to 3 As shown, the sealing structure 600 includes an elastic seal 610 sleeved on the rotating shaft 320. The elastic seal 610 is an elastic annular seal. The outer ring of the elastic seal 610 is fixed to the housing 100. The elastic seal 610 has a sealing lip 611 facing the rotating shaft 320. The sealing lip 611 is a lip-shaped portion of the inner edge of the elastic seal 610 that converges towards the rotating shaft 320. The inner diameter of the sealing lip 611 in its natural state is smaller than the outer diameter of the rotating shaft 320. After the elastic seal 610 is assembled in place, the sealing lip 611 is stretched open by the rotating shaft 320 and undergoes elastic deformation. The sealing lip 611 continuously presses against the outer circular surface of the rotating shaft 320 with elastic restoring force. After elastic deformation, the sealing lip 611 abuts against the outer circular surface of the rotating shaft 320 and dynamically seals with the rotating shaft 320. When the rotating shaft 320 rotates, the sealing lip 611 slides relative to the outer circular surface of the rotating shaft 320 and maintains contact with the outer circular surface. The sealing lip 611 maintains a tight, elastic seal against the rotating shaft 320. As the shaft 320 rotates, the sealing lip 611 seals the rotational gap between the shaft 320 and the housing 100, preventing liquid from seeping in along the shaft 320. The elastic deformation of the sealing lip 611 compensates for assembly tolerances between the shaft 320 and the housing 100, as well as wear during operation, ensuring a long-term effective seal.

[0089] In some embodiments, the resilient seal 610 has a single sealing lip 611. In other embodiments, the resilient seal 610 has two axially spaced sealing lips 611, wherein the sealing lip 611 closer to the airflow passage 120 is used to block liquid, and the sealing lip 611 closer to the receiving cavity 110 is used to block dust, forming a cavity for containing grease between the two sealing lips 611. The two sealing lips 611 share the responsibilities of blocking liquid and blocking dust, further improving the reliability of the seal. The material of the resilient seal 610 can be selected according to the operating conditions. In some embodiments, the sealing lip 611 of the resilient seal 610 is made of nitrile rubber, suitable for ambient temperature and humid conditions. In other embodiments, the sealing lip 611 is made of fluororubber, suitable for higher temperature conditions. In some embodiments, the operating temperature at the mating point between the sealing lip 611 and the rotating shaft 320 is -20°C to 120°C.

[0090] By setting an elastic seal 610 with an outer ring fixed to the housing 100 and an inner diameter of the sealing lip 611 smaller than the outer diameter of the rotating shaft 320 in its natural state, the sealing lip 611 continuously abuts against the outer surface of the rotating shaft 320 after elastic deformation, and maintains sliding contact when the rotating shaft 320 rotates. Thus, the elastic pre-tightening of the sealing lip 611 can compensate for assembly tolerances and operational wear, achieving long-term effective dynamic sealing.

[0091] In some implementations, reference Figure 2As shown, the elastic seal 610 is a waterproof gasket 612. A sealing groove is provided on the housing 100. The outer ring of the waterproof gasket 612 is embedded in the sealing groove. The sealing groove provides axial and radial restraint to the outer ring of the waterproof gasket 612. The inner lip of the waterproof gasket 612 forms a sealing lip 611. The inner lip is interference-fitted with the rotating shaft 320. The inner lip is fitted onto the rotating shaft 320 with an interference fit. When the rotating shaft 320 rotates, the inner lip forms a dynamic seal by interfering with the outer surface of the rotating shaft 320. In some embodiments, the waterproof gasket 612 is made of nitrile rubber or silicone rubber, which combines elasticity and moisture resistance. In some embodiments, the inner lip of the waterproof gasket 612 has a secondary lip on the side facing the airflow channel 120. The secondary lip makes light contact with the rotating shaft 320 and is used to block larger water droplets and dust before the main lip, reducing the burden on the main lip. The waterproof gasket 612 has a simple structure. A dynamic seal is achieved by the interference fit between the inner lip and the 320-degree rotating shaft. The outer ring is fixed by embedding it into the sealing groove. The waterproof gasket 612 is easy to assemble and has a low cost.

[0092] In some embodiments, the interference fit between the inner lip of the waterproof gasket 612 and the rotating shaft 320 is 0.05 mm to 0.3 mm. A larger interference fit results in a more reliable seal, but also increases the frictional resistance between the inner lip and the rotating shaft 320 during rotation. A larger interference fit is used when high sealing reliability is required; a smaller interference fit is used when high rotational resistance is required.

[0093] By embedding the outer ring of the waterproof gasket 612 into the sealing groove of the housing 100 and making the inner lip interfere with the rotating shaft 320, the inner lip interferes with the outer surface of the rotating shaft 320 to form a dynamic seal when the rotating shaft 320 rotates. This results in a simple structure, convenient assembly, and low cost.

[0094] It is understood that the resilient seal 610 can also be replaced with an oil seal 613 to accommodate higher speeds and longer operating times. In other embodiments, see reference... Figure 3As shown, the resilient seal 610 is an oil seal 613. The oil seal 613 includes a bracket and a resilient sealing lip fixed to the inner side of the bracket. This resilient sealing lip constitutes a sealing lip 611. In some embodiments, the bracket is a metal skeleton. An elastic ring is provided on the inner edge of the resilient sealing lip. The elastic ring is a tensioning ring surrounding the inner edge of the resilient sealing lip. The elastic ring tightens the resilient sealing lip concentrically. The elastic ring presses the resilient sealing lip against the outer surface of the rotating shaft 320. The bracket is fixed to the housing 100. The resilient sealing lip dynamically seals against the outer surface of the rotating shaft 320. When the rotating shaft 320 rotates at high speed, the elastic ring maintains the pressure of the resilient sealing lip on the rotating shaft 320. The elastic ring provides a stable radial pressure for the resilient sealing lip. The oil seal 613 is suitable for high speeds and long-term operation, and has a long sealing life. The bracket provides support for the resilient sealing lip, stabilizing its shape and position. Under high-speed operation, the resilient sealing lip is less prone to leakage due to pressure fluctuations. Thus, the waterproof gasket 612 and the oil seal 613 provide two implementations of the sealing structure 600. The waterproof gasket 612 emphasizes simple structure and low cost; the oil seal 613 emphasizes durable sealing at high speeds.

[0095] By fixing the oil seal 613 to the housing 100 with a bracket and tightening the elastic ring of the inner edge of the elastic sealing lip against the outer surface of the rotating shaft 320, the elastic ring maintains the pressure on the elastic sealing lip when the rotating shaft 320 rotates at high speed. As a result, the oil seal 613 is suitable for high speed and long-term operation, has a long sealing life, and is not prone to leakage under high speed operation.

[0096] In some embodiments, the stator assembly 200 includes a PCB board and winding coils. The PCB board is a printed circuit board. The PCB board is disk-shaped. A through hole is formed at the center of the PCB board for the shaft 320 to pass through. The shaft 320 passes through the through hole. The PCB board is in thermal contact with the heat-conducting structure 500. The winding coils are disposed on the surface of the PCB board. The winding coils are formed by etching. The winding coils are distributed circumferentially along the PCB board. The winding coils are axially opposite the magnetic element 310.

[0097] In some embodiments, a heat dissipation pad electrically connected to the winding coil is formed on the side of the PCB board facing away from the magnetic component 310. The heat dissipation pad is a copper-clad pad area. The distribution of the heat dissipation pads on the PCB board corresponds to the distribution of the winding coils on the PCB board, so that the areas of the winding coils where heat is concentrated correspond to the heat dissipation pads. The heat dissipation pads are in thermal contact with the heat-conducting structure 500. In some embodiments, the position of the heat dissipation pads is relative to the area of ​​the heat-conducting structure 500 in contact with the PCB board, so that heat is transferred from the heat dissipation pads to the heat-conducting structure 500 nearby.

[0098] In some embodiments, the PCB board thickness is 0.8 mm to 2 mm. Heat generated by the winding coil is transferred to the heat-conducting structure 500 via the PCB board and heat dissipation pads. When the winding coil is energized, a magnetic field is formed circumferentially on the surface of the PCB board. This magnetic field interacts axially with the magnetic component 310, driving the magnetic component 310 to rotate the shaft 320. The winding coil is integrally formed by etching along the PCB board. The stator assembly 200 is thinned axially. The motor is further compressed axially. The winding coil is distributed circumferentially along the PCB board and axially aligned with the magnetic component 310, forming an axially established magnetic flux. The PCB board is in direct thermal contact with the heat-conducting structure 500. Heat generated by the winding coil is dissipated nearby via the PCB board, preventing heat accumulation on the circuit board.

[0099] In some embodiments, each winding coil is a spoke-shaped coil extending radially along the PCB board, and multiple winding coils are arranged at uniform intervals circumferentially. In other embodiments, each winding coil is a flat coil spirally wound around its own center, and multiple winding coils are arranged circumferentially. The winding coils are grouped by phase circumferentially.

[0100] In some embodiments, the winding coils are divided into three phases, with winding coils of the same phase distributed circumferentially and connected in series or parallel. The number of phases of the winding coils corresponds to the number of poles of the magnetic component 310. In some embodiments, the magnetic component 310 has 8 to 16 poles. A higher number of poles results in a higher commutation frequency and smaller torque fluctuations at the same speed, but it also places higher demands on the etching linewidth and number of turns of the winding coils. When high torque stability is required, the magnetic component 310 has a higher number of poles; when the processing difficulty of the winding coils is high, the magnetic component 310 has a lower number of poles.

[0101] In other embodiments, the PCB board is a multilayer circuit board, with the winding coils distributed across different layers and interconnected via conductive vias to increase the number of winding turns within a limited radial dimension. In some embodiments, the side of the PCB board facing away from the magnetic component 310 has an array of thermally conductive vias in the area corresponding to the winding coils. These vias are filled with thermally conductive metal, guiding the heat from the winding coils through the thickness of the PCB board to the heat dissipation pads, and then to the thermally conductive structure 500. The thermally conductive vias provide a low thermal resistance path for the heat from the winding coils to pass through the thickness of the PCB board, allowing the heat generated by the winding coils to be transferred to the thermally conductive structure 500 more quickly.

[0102] In some embodiments, the rotor assembly 300 further includes a connector 330. The connector 330 is a disc-shaped member that carries the magnetic element 310. In some embodiments, the connector 330 is a magnetic back iron, and the connector 330 is made of a magnetically conductive material. An axial air gap is formed between the connector 330 and the stator assembly 200. The magnetic elements 310 are arranged circumferentially along the surface of the connector 330 facing the stator assembly 200. The magnetic poles of two adjacent magnetic elements 310 alternately oppose each other in the axial direction. That is, for two circumferentially adjacent magnetic elements 310, one has an N pole and the other has an S pole at the end facing the stator assembly 200. When the shaft 320 rotates, the magnetic elements 310 arranged circumferentially along the surface of the connector 330 with their magnetic poles alternately opposing in the axial direction sweep across the stator assembly 200 in sequence. The magnetic elements 310 form an alternating magnetic field in the axial air gap. This alternating magnetic field interacts with the windings of the stator assembly 200, continuously generating torque.

[0103] The connector 330 is a disc-shaped component made of a magnetically conductive material. In some embodiments, the connector 330 is made of low-carbon steel or silicon steel. The end of the magnetic element 310 facing away from the stator assembly 200 is attached to the connector 330. Magnetic flux emitted from the same magnetic element 310 passes through the axial air gap through the winding coils of the stator assembly 200, returns via adjacent opposite-pole magnetic elements 310, and closes along the connector 330 between adjacent magnetic elements 310. The connector 330 provides a low-resistivity return path for the magnetic flux.

[0104] In some embodiments, the thickness of the connector 330 is 1 mm to 4 mm. If the connector 330 is too thin, the magnetic flux will saturate within the connector 330, and the magnetic field will be weakened; if the connector 330 is too thick, the moment of inertia and axial dimension of the rotor assembly 300 will increase. When a higher magnetic field strength is required, the connector 330 is made with a larger thickness; when a lighter rotor is required, the connector 330 is made with a smaller thickness. The magnetic component 310 can be bonded and fixed to the connector 330, or it can be circumferentially limited by a mounting groove on the surface of the connector 330. The connector 330 carries the magnetic component 310 and forms an axial magnetic flux loop for the magnetic component 310. The magnetic field in the axial air gap is enhanced. The magnetic poles of adjacent magnetic components 310 alternate with opposite directions, creating an alternating magnetic field in the axial air gap when the rotor assembly 300 rotates. The motor output is smooth.

[0105] By setting the connector 330 to support the magnetic component 310 and arranging its magnetic poles alternately in opposite directions circumferentially in the axial direction, an alternating magnetic field is formed in the axial air gap when the rotor assembly 300 rotates. Thus, the connector 330 forms an axial magnetic flux loop for the magnetic component 310, enhancing the magnetic field in the air gap and making the motor output stable.

[0106] In some embodiments, the rotor assembly 300 further includes a bearing assembly 700. The bearing assembly 700 is disposed in the stator assembly 200. The shaft 320 is rotatably supported on the housing 100 via the bearing assembly 700. In some embodiments, the bearing assembly 700 includes a single bearing.

[0107] In other embodiments, the bearing assembly 700 includes two bearings spaced apart along the axial direction. The two bearings respectively support the two ends of the shaft 320. When the shaft 320 rotates, the bearing assembly 700 bears radial and axial loads and maintains the rotation center of the shaft 320.

[0108] In some embodiments, the bearing of the bearing assembly 700 is a deep groove ball bearing, which bears both radial and axial loads.

[0109] In other embodiments, the bearing assembly 700 includes a pair of angular contact ball bearings arranged back-to-back and axially preloaded to eliminate axial movement of the shaft 320.

[0110] When the bearing assembly 700 includes two bearings spaced apart axially, both bearings are fitted onto the shaft 320, and a spacer sleeve is provided between them axially, defining the axial distance between the inner rings of the two bearings. The shaft 320 is supported by the two bearings, reducing the radial runout of the shaft 320 under high-speed rotation.

[0111] In some embodiments, the bearings of the bearing assembly 700 are pre-lubricated sealed bearings, which are self-lubricated and sealed by their own dust covers, requiring no additional lubrication during the service life of the fan. The dust covers of the sealed bearings also prevent a small amount of moisture that has crossed the sealing structure 600 from contacting the bearing raceways. The bearing assembly 700 is disposed within the stator assembly 200. The support position of the shaft 320 is located within the area where the stator assembly 200 is located. The shaft 320 rotates smoothly with minimal wear. The bearing assembly 700 occupies the axial space of the stator assembly 200 and does not additionally increase the axial dimension of the fan.

[0112] By placing the bearing assembly 700 in the stator assembly 200 and supporting the shaft 320 on the housing 100 via the bearing assembly 700, the support position of the shaft 320 is located within the area of ​​the stator assembly 200. As a result, the shaft 320 rotates smoothly and experiences less wear. Furthermore, the bearing assembly 700 occupies the axial space of the stator assembly 200 without increasing the axial dimension of the fan.

[0113] In some embodiments, the housing 100 is provided with an axial positioning surface. The axial positioning surface is formed by a stepped surface on the inner wall of the housing 100. The rotating shaft 320 is provided with a shoulder. One side of the bearing assembly 700 abuts against the shoulder of the rotating shaft 320. The other side of the bearing assembly 700 abuts against the axial positioning surface. The relative positions of the inner and outer rings of the bearing assembly 700 along the axial direction of the rotating shaft 320 are defined by the shoulder and the axial positioning surface. After the bearing assembly 700 is limited by the shoulder and the axial positioning surface on both sides, the axial position of the rotating shaft 320 relative to the housing 100 is fixed. The axial air gap formed between the magnetic element 310 and the stator assembly 200 is thus fixed.

[0114] In some embodiments, the axial air gap is between 0.2 mm and 1.5 mm. A smaller axial air gap results in stronger axial magnetic flux and greater motor output, but also places higher demands on assembly precision. A smaller axial air gap is used when higher output is required; a larger axial air gap is used when higher tolerances for assembly tolerances are required. The axial air gap remains constant as the shaft 320 rotates.

[0115] In some embodiments, the axial distance between the shoulder and the axial locating surface determines the axial position of the bearing assembly 700 and even the shaft 320 relative to the housing 100, and thus determines the axial air gap. This axial distance is determined during the machining of the housing 100 and the shaft 320. During assembly, there is no need to measure the axial air gap online; the set axial air gap is obtained by placing both ends of the bearing assembly 700 against the shoulder and the axial locating surface, respectively.

[0116] In some embodiments, an adjusting shim is provided between the shoulder and the axial positioning surface, allowing for fine-tuning of the axial air gap by replacing shims of different thicknesses. The axial air gap is crucial for the axial interaction between the magnetic component 310 and the stator assembly 200. The shoulder and axial positioning surface limit the bearing assembly 700 from both sides, fixing the axial air gap after assembly and preventing drift during operation. This ensures stable motor output. The axial positioning surface is directly formed by the stepped surface of the inner wall of the housing 100, eliminating the need for additional independent positioning parts.

[0117] By setting the stepped surface of the inner wall of the housing 100 to form an axial positioning surface, one side of the bearing assembly 700 is abutted by the shoulder of the rotating shaft 320 and the other side is abutted by the axial positioning surface. Thus, the axial position of the rotating shaft 320 relative to the housing 100 is fixed, the axial air gap between the magnetic component 310 and the stator assembly 200 is fixed after assembly and does not drift during operation, and the motor output is stable.

[0118] In some implementations, reference Figure 1As shown, the fan also includes a support member 800. In some embodiments, the support member 800 is a lower flange. The support member 800 has a central hole through which a rotating shaft 320 passes. The rotating shaft 320 passes through the central hole. The inner wall of the support member 800 has a bearing housing. The bearing housing supports the bearing assembly 700.

[0119] In some embodiments, the bearing housing supports the outer ring of the bearing assembly 700. The support member 800 is fixedly connected to the housing 100.

[0120] In some embodiments, the support member 800 is fixedly connected to the housing 100 by fasteners, specifically screws. The rotor assembly 300 is axially constrained between the support member 800 and the housing 100. The support member 800 supports the bearing assembly 700 via a bearing housing. The shaft 320 passes through the central hole of the support member 800. The bearing housing is an axially recessed annular step on the inner wall of the support member 800, and the outer ring of the bearing assembly 700 is embedded in and radially limited by the bearing housing.

[0121] In some embodiments, the support member 800 is made of metal and also serves as part of a heat conduction path, transferring some of the heat from the bearing assembly 700 and the stator assembly 200 through the support member 800. The support member 800 is fixedly connected to the housing 100. This fixed connection can be a threaded fastener connection or a snap-fit ​​connection between the support member 800 and the housing 100. When using a threaded fastener connection, the edge of the support member 800 has multiple threaded holes spaced circumferentially, through which fasteners pass to secure the support member 800 to the housing 100. After the support member 800 is fixedly connected to the housing 100, the rotor assembly 300 is clamped from both axial sides by the support member 800 and the housing 100. The axial position of the rotor assembly 300 is constrained. The support member 800 provides an independent bearing seat for the bearing assembly 700. The rotor assembly 300 is positioned by the support member 800 and both ends of the housing 100, ensuring a secure assembly. The support 800 and the housing 100 can be machined separately and then fixedly connected, which facilitates the installation of the rotor assembly 300 and axial constraint.

[0122] By setting the support member 800 to support the bearing assembly 700 via the bearing seat and to fix it to the housing 100, the rotor assembly 300 is clamped and positioned by the support member 800 and the housing 100 from both sides of the axial direction, thereby ensuring a stable assembly. Furthermore, the support member 800 and the housing 100 can be processed separately and then fixedly connected, which facilitates the installation of the rotor assembly 300 and axial constraint.

[0123] In some embodiments, the sealing structure 600 is axially disposed between the impeller 400 and the bearing assembly 700. An axial gap exists between the sealing structure 600 and the impeller 400. An axial gap also exists between the sealing structure 600 and the bearing assembly 700.

[0124] In other embodiments, there is an axial gap between the sealing structure 600 and the impeller 400, and the sealing structure 600 is fitted with the bearing assembly 700.

[0125] In some other embodiments, there is an axial gap between the sealing structure 600 and the bearing assembly 700, and the sealing structure 600 is fitted with the impeller 400.

[0126] The sealing structure 600 axially isolates the receiving cavity 110 from the airflow passage 120. When liquid from the airflow passage 120 moves along the shaft 320 toward the receiving cavity 110, it is intercepted upon reaching the sealing structure 600. The liquid is blocked before reaching the bearing assembly 700 and the receiving cavity 110.

[0127] In some embodiments, the axial gap between the sealing structure 600 and the bearing assembly 700 is 0.5 mm to 3 mm. This gap prevents the liquid intercepted at the sealing structure 600 from directly contacting the bearing assembly 700 and provides space for the liquid to be thrown away as the shaft 320 rotates. The axial gap between the sealing structure 600 and the impeller 400 protects the sealing structure 600 from direct scouring by the rotating airflow of the impeller 400. The sealing structure 600 is located between the impeller 400 and the bearing assembly 700. The liquid is intercepted before reaching the bearing assembly 700 and the receiving cavity 110. The bearing assembly 700 and the stator assembly 200 are protected simultaneously. The gaps on both sides of the sealing structure 600 axially isolate the receiving cavity 110 from the airflow channel 120, preventing liquid or airflow from interfering with each other at the gaps.

[0128] By axially positioning the sealing structure 600 between the impeller 400 and the bearing assembly 700, and leaving an axial gap between the sealing structure 600 and the impeller 400 and / or between the sealing structure 600 and the bearing assembly 700, the liquid on the airflow channel 120 side moves along the rotating shaft 320 toward the receiving cavity 110 and is intercepted upon reaching the sealing structure 600. Thus, the bearing assembly 700 and the stator assembly 200 are protected simultaneously, and the gap prevents liquid or airflow from interfering with each other.

[0129] This application embodiment also provides a cleaning device. The cleaning device includes a device body and the aforementioned fan. The fan is disposed on the device body. The device body is the main body of the cleaning device that carries the fan and performs the cleaning function. The fan provides the airflow required for the cleaning device's operation. When the cleaning device is working, the impeller 400 of the fan disposed on the device body rotates, generating the airflow required for the operation. When the cleaning device operates in a humid environment, the wastewater and water vapor generated during operation approach the fan and are blocked outside the receiving cavity 110 by the fan's sealing structure 600. The heat of the fan stator assembly 200 is discharged through the airflow channel 120 via the heat conduction structure 500. After adopting the aforementioned fan, the entire machine tends to be miniaturized and flattened due to the compression of the fan's axial and radial dimensions. In a humid operating environment, the fan does not short-circuit due to liquid ingress or demagnetize due to heat accumulation. The operational reliability of the cleaning device is improved.

[0130] The blower can be applied to various types of cleaning equipment. In some embodiments, the cleaning equipment is a floor scrubber, the main body of which includes a roller brush and a wastewater recovery air path. The airflow generated by the blower is used to draw wastewater from the floor along with the airflow into the wastewater recovery air path. In other embodiments, the cleaning equipment is an upright or handheld vacuum cleaner, the main body of which includes a dust collection chamber. The airflow generated by the blower is used to draw dust and debris into the dust collection chamber through the suction port. In still other embodiments, the cleaning equipment is a robotic vacuum cleaner, the main body of which includes a chassis and a dust box. The airflow generated by the blower is used to draw the swept dust and debris into the dust box. The operating environment of all the above-mentioned cleaning equipment may contain wastewater or moisture. The blower's shaft end seal and airflow channel 120 can dissipate heat, enabling small-scale and reliable operation in humid environments.

[0131] As a relatively independent component, the fan can be reused in different equipment bodies. In some embodiments, the fan's outlet is connected to the equipment body's suction port via an air duct, and the negative pressure generated by the fan acts on the surface to be cleaned through the suction port. In other embodiments, the fan's inlet is connected to the dust-air separation chamber of the equipment body via an air duct, and the fan draws in the clean airflow after dust-air separation. Fans of the same specification can be installed in different equipment bodies, only requiring adaptation of the connection method between the inlet / outlet and the equipment body's air duct. The miniaturization and reliability of the fan in humid environments make it independent of the form of a specific equipment body. It should be noted that the specific forms of the aforementioned equipment bodies are merely examples, and the fan in this application does not depend on the specific form of the equipment body.

[0132] It should be understood that the application of this invention is not limited to the detailed structure and arrangement of the components proposed herein. This invention can have other embodiments and can be implemented and performed in various ways. The foregoing variations and modifications fall within the scope of this invention. It should be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more individual features mentioned or apparent in the text and / or drawings. All these different combinations constitute multiple alternative aspects of the invention. The embodiments of this invention illustrate the best known mode for carrying out the invention and will enable those skilled in the art to utilize the invention.

Claims

1. A fan, characterized in that, include: A housing having a receiving cavity and an airflow channel communicating with the receiving cavity; The stator assembly is disposed within the receiving cavity; A rotor assembly includes a magnetic element and a rotating shaft. The magnetic element is disposed in the receiving cavity. The magnetic element and the stator assembly are disposed opposite each other along the axial direction of the rotating shaft. The rotating shaft is rotatably disposed in the housing. One end of the rotating shaft extends out of the receiving cavity and into the airflow channel. An impeller is disposed at one end of the rotating shaft located in the airflow channel; A heat-conducting structure is disposed on the side of the stator assembly opposite to the rotor assembly and is in thermal contact with the stator assembly, the heat-conducting structure being at least partially exposed in the airflow channel; A sealing structure is provided at the position where the rotating shaft extends out of the receiving cavity and is dynamically sealed with the rotating shaft to prevent liquid in the airflow channel from entering the receiving cavity along the rotating shaft.

2. The fan according to claim 1, characterized in that, An insert hole is provided on the inner wall of the housing; The heat-conducting structure includes a heat-conducting block embedded in the mounting hole, and the heat-conducting block is sealed to the mounting hole; One side of the heat-conducting block is in thermal contact with the stator assembly, and the other side extends into the airflow channel to form a heat dissipation section.

3. The fan according to claim 1, characterized in that, The casing is made of metal. The thermally conductive structure includes a thermally conductive medium filled between the stator assembly and the inner wall of the housing, the thermally conductive medium thermally connecting the stator assembly and the inner wall surface of the housing; At least a portion of the inner wall surface of the housing forms the wall surface of the airflow channel, and this portion of the inner wall surface is exposed in the airflow channel to form a heat dissipation section.

4. The fan according to claim 2 or 3, characterized in that, The heat dissipation section has multiple fins spaced apart on the surface exposed to the airflow channel; the extension direction of each fin is parallel to the airflow direction in the airflow channel, and a heat dissipation channel for airflow is formed between two adjacent fins.

5. The fan according to claim 2 or 3, characterized in that, The heat dissipation section has multiple fins on the surface exposed to the airflow channel; the multiple fins are arranged in a circumferential array along the axis of rotation, and the extension direction of each fin intersects the radial direction of the axis of rotation.

6. The fan according to claim 1, characterized in that, The sealing structure includes an elastic seal sleeved on the rotating shaft, and the outer ring of the elastic seal is fixed to the housing; The resilient seal has a sealing lip facing the rotating shaft; The inner diameter of the sealing lip in its natural state is smaller than the outer diameter of the rotating shaft. After elastic deformation, the sealing lip abuts against the outer circular surface of the rotating shaft and dynamically seals with the rotating shaft.

7. The fan according to claim 6, characterized in that, The elastic sealing element is a waterproof gasket; The housing has a sealing groove, and the outer ring of the waterproof gasket is embedded in the sealing groove; The inner lip of the waterproof gasket forms the sealing lip, and the inner lip is interference-fitted with the rotating shaft.

8. The fan according to claim 6, characterized in that, The elastic seal is an oil seal; the oil seal includes a bracket and an elastic sealing lip fixed to the inner side of the bracket; The inner edge of the elastic sealing lip is provided with an elastic ring, which presses the elastic sealing lip against the outer surface of the rotating shaft; The bracket is fixed to the housing, and the elastic sealing lip is dynamically sealed to the outer circular surface of the rotating shaft.

9. The fan according to claim 1, characterized in that, The stator assembly includes: The PCB board has a through hole in its center for the rotating shaft to pass through, and the PCB board is in thermal contact with the heat-conducting structure. A winding coil is disposed on the surface of the PCB board. The winding coil is formed by etching and distributed circumferentially along the PCB board. The winding coil is opposite to the magnetic component in the axial direction.

10. The fan according to claim 1, characterized in that, The rotor assembly also includes a connector, and an axial air gap is formed between the connector and the stator assembly. The magnetic elements are arranged circumferentially along the surface of the connector toward the stator assembly, and the magnetic poles of two adjacent magnetic elements alternately oppose each other in the axial direction.

11. The fan according to claim 1, characterized in that, The rotor assembly also includes: A bearing assembly is disposed in the stator assembly, and the rotating shaft is rotatably supported on the housing via the bearing assembly.

12. The fan according to claim 11, characterized in that, The housing is provided with an axial positioning surface, which is formed by a stepped surface on the inner wall of the housing; One side of the bearing assembly abuts against the shoulder of the rotating shaft, and the other side abuts against the axial positioning surface, thereby defining the axial air gap formed between the magnetic element and the stator assembly.

13. The fan according to claim 11, characterized in that, The fan also includes a support member, and the support member has a central hole for the rotating shaft to pass through. The inner wall of the support member is provided with a bearing seat for supporting the bearing assembly; The support member is fixedly connected to the housing, and the rotor assembly is axially constrained between the support member and the housing.

14. The fan according to claim 11, characterized in that, The sealing structure is disposed axially between the impeller and the bearing assembly; The sealing structure has a gap along the axial direction between itself and the impeller, and / or the sealing structure has a gap along the axial direction between itself and the bearing assembly, so as to isolate the receiving cavity from the airflow passage in the axial direction.

15. A cleaning device, characterized in that, include: Equipment body; The fan as described in any one of claims 1 to 14, wherein the fan is disposed on the equipment body.

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