Dustproof structure of brushless motor

Abstract

The invention discloses a dustproof structure of a brushless motor, and belongs to the technical field of electric tools. The dustproof structure comprises a casing, a rotor and a stator, and further comprises a wind blocking ring arranged at the front end of the stator, a fan blade sleeved at the front end of a rotor mandrel, and at least two split type sealing components arranged in a central hole of the wind blocking ring. The at least two split type sealing components are encircled along the circumferential direction to form an annular structure, the front end of the annular structure forms a fence part protruding towards the fan blade direction, and the fence part at least partially extends into the fan blade and is matched with the fan blade to form a sealing structure at the front end of the rotor. The independent fence part formed by the split type sealing component extends into the fan blade, so that the front end of the rotor is effectively sealed on the premise of not sacrificing the blade length of the fan blade, and the technical problem that the dustproof performance and the heat dissipation efficiency are difficult to consider at the same time in the prior art is solved; and the working reliability and the service life of the brushless motor in a dust environment are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of power tool technology, specifically relating to a brushless motor, and more particularly to a brushless motor with a dustproof structure. Background Technology

[0002] Brushless motors are widely used in power tools, home appliances, and industrial equipment due to their high efficiency, long lifespan, and low noise. The demand for brushless motors is particularly increasing for metal cutting and grinding power tools operating in dusty environments. However, the rotors of brushless motors are typically made of permanent magnet materials, which have strong magnetism. When the motor is used in an environment containing ferrous dust or metal particles, the cooling airflow introduced by the internal fan can bring these dust particles into the motor. Once this ferrous dust enters the air gap between the rotor and stator, it is easily attracted by the permanent magnet rotor and is difficult to remove. Long-term accumulation can lead to air gap blockage, causing serious malfunctions such as rotor-stator friction (scouring), seizing, or even burnout, severely affecting the motor's lifespan and operational reliability. Therefore, effectively preventing dust from entering the brushless motor, especially preventing ferrous dust from being attracted by the permanent magnet rotor, has become a pressing technical problem to be solved in this field.

[0003] To address the aforementioned issues, various dustproof structures for brushless motors have been disclosed in the prior art. For example, the applicant previously proposed a dustproof structure for a brushless motor (patent application number: CN201820462735.X). This structure includes a housing, a rotor, and a stator. By setting front and rear dustproof end plates at both ends of the stator core, and cooperating with front and rear insulating end plates and O-rings, the rotor space inside the stator is physically isolated from the winding slots. Simultaneously, a fan blade and a baffle ring are installed at the front end of the rotor. The first isolation ring on the fan blade and the second isolation ring on the baffle ring (the outer diameter of the first isolation ring is slightly smaller than the inner diameter of the second isolation ring) work together to achieve a non-contact seal at the front end of the rotor. This solution effectively prevents dust from entering the rotor space and discharges dust particles entering the coils through ventilation spaces and air guide holes, significantly improving the adaptability of brushless motors in dusty environments and representing an important improvement in this technical field.

[0004] However, further practical applications have revealed that while the aforementioned existing technical solutions offer good dustproof performance, their blade-windshield mating structure has certain limitations. Specifically, to achieve an effective seal, the second isolation ring on the windshield needs to form a certain mating depth with the first isolation ring on the blade, which compresses the axial length of the blade. To maintain the necessary sealing effect, some blade length must be sacrificed, thus affecting the heat dissipation efficiency of the blade to some extent. In other words, there is a structural contradiction between dustproof performance and heat dissipation efficiency. How to maintain the original dimensions and heat dissipation efficiency of the blade to the maximum extent while ensuring dustproof performance has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention aims to solve the aforementioned problems in the prior art and provide an improved dustproof structure for brushless motors. Specifically, the technical problem this invention addresses is: based on existing dustproof structures, how to ensure the sealing effect at the rotor front end without sacrificing the length of the fan blades, thereby maintaining good dustproof performance while maximizing the heat dissipation efficiency of the fan blades, and resolving the structural contradiction between dustproof performance and heat dissipation efficiency.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A dustproof structure for a brushless motor includes a housing, a rotor, and a stator surrounding the rotor. The stator includes a stator core and several coils. The rotor includes a rotor spindle and a rotor core disposed in a central rotor space within the stator core. The dustproof structure further includes: a windproof ring disposed at the front end of the stator, with a central hole for the rotor spindle to pass through; a fan blade fitted onto the front end of the rotor spindle and located in front of the windproof ring; and at least two separate sealing components disposed within the central hole of the windproof ring. The at least two separate sealing components circumferentially enclose and form an annular structure. The front end of the annular structure forms a fence portion protruding towards the fan blade, at least partially extending into the interior of the fan blade, cooperating with the fan blade to form a sealing structure at the front end of the rotor.

[0008] Preferably, the split-type sealing component consists of two semi-annular plastic parts, which face each other and enclose each other within the central hole of the windbreak ring, with their mating surfaces extending axially. This split-type structure is easy to install and can form a complete ring-shaped enclosure.

[0009] Preferably, the enclosure section has a cylindrical structure, with its outer diameter smaller than the inner diameter of the fan blade, and a labyrinth seal structure with a gap fit is formed between the outer wall of the enclosure section and the inner wall of the fan blade. By forming a tortuous gap path, dust can be effectively prevented from entering.

[0010] More preferably, the outer wall of the fence section is provided with at least one circumferentially extending rib or groove to further increase the length and tortuosity of the sealing path, thereby enhancing the labyrinth sealing effect.

[0011] Preferably, the rear end of the split sealing component has a mounting portion that fits against the inner wall of the central hole of the windshield, and a positioning structure is provided on the outer circumferential surface of the mounting portion to restrict the axial movement and circumferential rotation of the split sealing component relative to the windshield, thereby ensuring the stability of the assembly and the reliability of the seal.

[0012] More preferably, the positioning structure includes a positioning protrusion disposed on the outer peripheral surface of the mounting part and a positioning groove disposed on the inner wall of the central hole of the windshield, wherein the positioning protrusion and the positioning groove cooperate; or, the positioning structure includes a positioning plane disposed on the outer peripheral surface of the mounting part and a mating plane disposed on the inner wall of the central hole of the windshield. These positioning methods are simple and effective, and facilitate manufacturing and assembly.

[0013] Preferably, the fan blade is a centrifugal fan blade, comprising a blade section and a hub section, wherein the inner ring of the hub section is fitted onto the rotor spindle, and the guard section extends into the inner space of the hub section. This arrangement allows the guard section to penetrate deep into the fan blade to form a seal without occupying the axial space of the blade.

[0014] Preferably, the dustproof structure further includes a front dustproof end plate and a rear dustproof end plate. The front dustproof end plate is disposed at the front end of the stator core, and the rear dustproof end plate is disposed at the rear end of the stator core. The front and rear dustproof end plates each include an annular cover and several isolation plates. The isolation plates are inserted into through slots on the stator core that connect the winding slots to the rotor space, isolating the winding slots from the rotor space. This structure, in conjunction with the front-end sealing structure, forms a complete seal for the rotor space.

[0015] More preferably, the rear end face of the split sealing component abuts against the front end face of the front dustproof end plate, forming an axial compression fit. This fit helps eliminate assembly gaps and improves overall sealing performance.

[0016] Preferably, the split sealing component is made of an elastic material, forming an elastic interference fit between it and the inner wall of the central hole of the windshield to compensate for manufacturing tolerances and enhance sealing; or, the split sealing component is made of a rigid material, and a sealing gasket is provided between it and the inner wall of the central hole of the windshield, which can also achieve a good sealing effect.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] First, this invention constructs a novel rotor front-end sealing method by setting at least two separate sealing components to form a ring structure within the central hole of the windshield ring, with the front end of the sealing component extending into the interior of the fan blade. Compared to the existing technology that relies on the cooperation of a first isolation ring on the fan blade and a second isolation ring on the windshield ring, the sealing component of this invention is set independently of the fan blade, and its axial length can be freely designed according to sealing requirements without occupying or compressing the axial space of the fan blade itself. Therefore, the technical solution of this invention can maintain or even enhance the sealing effect while allowing the fan blade to maintain its original blade length design, thereby effectively maintaining the heat dissipation efficiency of the fan blade and solving the technical contradiction in the prior art where dustproof performance and heat dissipation efficiency are difficult to balance.

[0019] Secondly, the present invention employs a split-type sealing component design, which not only facilitates installation within the limited space between the windshield ring and the rotor spindle, but also allows for reliable fixing and effective sealing with the windshield ring by selecting different materials (such as elastic materials) or setting positioning structures. The opposing enclosing method of the two semi-annular components can form a complete annular enclosure, avoiding the problem of difficult installation of integral components, while also reducing manufacturing difficulty and cost.

[0020] Third, by further adding ribs or grooves to the outer wall of the enclosure, the present invention can form a more complex labyrinthine sealing path, significantly enhancing its ability to prevent dust intrusion. Simultaneously, the abutting fit between the enclosure and the front dustproof end plate effectively connects the front-end sealing structure with the internal dustproof structure of the stator, forming a comprehensive dustproof system from the front end to the interior. Testing has shown that, under the same dusty conditions, the motor lifespan of the present invention is extended by more than 50% compared to existing technologies, significantly improving the reliability of brushless motors in harsh dusty environments. Attached Figure Description

[0021] To make the above-mentioned objectives, technical solutions, and beneficial effects of the present invention clearer, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are simplified or schematic, used only to assist in illustrating the concept of the present invention, and should not be construed as limiting the scope of protection of the present invention. The same reference numerals in the drawings represent the same or similar components.

[0022] Figure 1 This is a schematic diagram illustrating an embodiment of the present invention in which the lower dust cover and the EVA foam pad are combined.

[0023] Figure 2 This is a schematic diagram illustrating an embodiment of the present invention in which the lower dust cover and the O-ring are engaged.

[0024] Figure 3 This is a cross-sectional view of the overall structure of a brushless motor in one embodiment of the present invention;

[0025] Figure 4 This is an exploded view of a brushless motor dustproof structure in one embodiment of the present invention;

[0026] Figure 5 This is a cross-sectional view of the internal structure of a brushless motor in one embodiment of the present invention;

[0027] Figure 6 for Figure 5 Exploded structural view;

[0028] Figure 7 This is a schematic diagram of the assembly structure of the windshield ring and the sealing component in one embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram of the cooperative structure of the windshield ring, the upper dust cover, and the fan blades in one embodiment of the present invention;

[0030] Figure 9 This is a schematic diagram comparing the length of a wind turbine blade in an embodiment of the present invention with that in the prior art.

[0031] Explanation of the markings on the attached diagram:

[0032] 1-Casing; 2-Rotor; 3-Stator; 4-Fan blade; 5-Wind baffle; 6-Front dustproof end plate; 7-Front insulating end plate; 8-Rear insulating end plate; 9-Rear dustproof end plate; 10-O-ring; 2-1-Rotor core; 2-2-Rotor spindle; 3-1-Stator core; 3-2-Coil; 3-3-Wound slot; 3-4-Ventilation space; 3-5-Rotor space; 3-6-Through slot; 5-1- Outer edge; 5-2-Air guide hole; 6-1-Isolation plate of front dustproof end plate; 6-2-Ring cover of front dustproof end plate; 7-1-Protrusion; 8-1-Structure of rear insulating end plate; 9-1-Isolation plate; 9-2-Ring cover; 10-1-EVA foam pad; 10-2-O-ring rubber ring; 11-First split sealing component; 12-Second split sealing component; 13-Fence section; 14-Mounting section. Detailed Implementation

[0033] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the following embodiments are only for explaining the present invention and do not constitute any limitation on the scope of protection of the present invention. All equivalent substitutions or transformations made based on the technical concept of the present invention should fall within the scope of protection of the present invention.

[0034] like Figure 3 and Figure 4As shown, this embodiment provides a dustproof structure for a brushless motor, including a housing 1, a rotor 2, and a stator 3 surrounding the rotor 2. The rotor 2 includes a rotor core 2-1 and a rotor spindle 2-2 penetrating the rotor core 2-1. A permanent magnet (not shown) is embedded within the rotor core 2-1. The stator 3 includes a stator core 3-1 and several coils 3-2 wound on the stator core 3-1. A rotor space 3-5 for accommodating the rotor core 2-1 is formed in the center of the stator core 3-1. Multiple winding slots 3-3 are circumferentially formed on the stator core 3-1, and the coils 3-2 are embedded in the winding slots 3-3. The space between two adjacent coils 3-2 in the winding slots 3-3 forms a ventilation space 3-4 for the flow of cooling air. The winding slots 3-3 and the rotor space 3-5 are connected by a through slot 3-6. This through slot 3-6 is open in conventional brushless motor designs, but in this invention, it needs to be isolated by a dustproof structure.

[0035] To prevent dust from entering the rotor space 3-5 through the front end of rotor 2, the present invention provides a sealing structure at the front end of rotor 2, consisting of a fan blade 4, a baffle ring 5, and a split sealing component. Specifically, the fan blade 4 is sleeved and fixed to the front end of rotor spindle 2-2 and rotates synchronously with rotor 2. The fan blade 4 is preferably a centrifugal fan blade, which includes a hub located at the center and multiple blades extending radially outward along the hub. The inner ring of the hub is interference-fitted with rotor spindle 2-2 or fixed by a key connection.

[0036] The wind baffle ring 5 is fixedly installed at the front end of the stator 3. The wind baffle ring 5 has an annular outer edge 5-1. Specifically, the outer edge 5-1 of the wind baffle ring 5 is fixedly connected to the inner wall of the housing 1 or to the front end face of the stator 3. The wind baffle ring 5 is located between the fan blade 4 and the stator 3, and a central hole is opened in its center for the rotor spindle 2-2 to pass through. Multiple air guide holes 5-2 are opened circumferentially on the wind baffle ring 5. The positions of these air guide holes 5-2 correspond one-to-one with the ventilation spaces 3-4 on the stator core 3-1, and are used to guide the cooling airflow.

[0037] like Figures 5 to 8As shown, the core improvement of this invention lies in the provision of at least two separate sealing components within the central hole of the windshield ring 5. In this embodiment, the separate sealing components are two semi-annular sealing components, namely, the first separate sealing component 11 and the second separate sealing component 12. The two sealing components enclose each other within the central hole of the windshield ring 5, forming a complete annular structure. The front end of this annular structure (i.e., the end facing the fan blade 4) forms a fence portion 13 protruding towards the fan blade 4. The fence portion 13 has a cylindrical structure, and its axial length is designed according to the sealing requirements, typically 5-15 mm. After assembly, the fence portion 13 extends at least partially into the interior of the fan blade 4, specifically into the inner space of the hub portion of the fan blade 4. The outer wall of the fence portion 13 and the inner wall of the fan blade 4 form a clearance fit, maintaining a small gap of 1.5-2.5 mm between them, thus constituting a non-contact labyrinth seal structure. The relationship between the depth of the fence section 13 extending into the fan blade 4 and the sealing effect can be determined through experimental optimization. In this embodiment, the preferred range is 10-20 mm.

[0038] The advantage of this design is that the enclosure section 13 is set independently of the fan blade 4, and its axial length can be freely designed as needed without sacrificing the blade length of the fan blade 4 itself. For example... Figure 9 As shown, compared with the existing technology that relies on the cooperation of the first isolation ring on the fan blade and the second isolation ring on the wind deflector (length A in the figure), the blade length of the fan blade 4 in the present invention (length B in the figure) can maintain the original design length, thereby ensuring that the heat dissipation efficiency of the fan blade 4 is not affected by the sealing structure.

[0039] To further enhance the sealing effect, at least one circumferentially extending rib can be provided on the outer wall of the enclosure 13. The cross-sectional shape of the rib can be rectangular, triangular, or semi-circular, and its height is slightly smaller than the gap between the enclosure 13 and the inner wall of the fan blade 4, so that a narrower gap is formed between the rib and the inner wall of the fan blade 4, increasing airflow resistance. In an alternative, grooves can be used instead of ribs, which can also form a tortuous sealing path. The specific number, shape, size, and arrangement of the ribs can be adjusted according to the results of airflow simulation analysis to achieve the best sealing effect and the minimum wind resistance loss.

[0040] The rear end of the split-type sealing component has a mounting portion 14, which fits against the inner wall of the central hole of the windshield ring 5. To ensure accurate positioning and reliable fixation of the split-type sealing component within the windshield ring 5, a positioning structure is provided on the outer peripheral surface of the mounting portion 14. In this embodiment, the positioning structure may include a positioning protrusion on the outer peripheral surface of the mounting portion 14 and a positioning groove on the inner wall of the central hole of the windshield ring 5. The positioning protrusion and the positioning groove cooperate to restrict the axial movement and circumferential rotation of the split-type sealing component relative to the windshield ring 5. In an alternative embodiment, the positioning structure may also take the form of a positioning plane and a mating plane, that is, at least one plane is machined on the outer peripheral surface of the mounting portion 14, and a corresponding mating plane is machined on the inner wall of the central hole of the windshield ring 5, thereby preventing rotation through planar mating. In addition to the cooperation between the positioning protrusion and the positioning groove, the split-type sealing component and the windshield ring 5 may also be fixed by auxiliary fixing methods such as ultrasonic welding, hot riveting, and bonding to enhance the reliability of the connection.

[0041] Regarding the material selection for the split-type sealing component, there are several alternative options. One option is to use an elastic material, such as rubber or thermoplastic elastomer (TPE), utilizing its elastic deformation to achieve an interference fit with the center hole of the windshield ring 5, thus achieving both sealing and compensating for manufacturing tolerances. Another option is to use a rigid material, such as reinforced nylon or PBT plastic. In this case, a sealing gasket (not shown in the figure) can be placed between the mounting part and the inner wall of the center hole of the windshield ring 5, or an adhesive can be used for fixation. In this embodiment, both the split-type sealing component and the fan blade 4 are made of PA66-GF30 nylon material. Whether wear-resistant agents, lubricants, etc., need to be added can be determined by those skilled in the art based on actual working conditions.

[0042] like Figure 5 and Figure 6 As shown, the dustproof structure of the present invention also includes a dustproof component disposed inside the stator 3, which works in conjunction with the front sealing structure to form a complete seal for the rotor space 3-5. Specifically, a front insulating end plate 7 and a rear insulating end plate 8 are respectively disposed at the front and rear ends of the stator core 3-1. Several hollow protrusions 7-1 are provided on the front insulating end plate 7 and the rear insulating end plate 8 at the positions corresponding to the winding slots 3-3, and are installed at both ends of the stator core 3-1 through the protrusions 7-1.

[0043] A front dustproof end plate 6 is provided on the outer side of the front insulating end plate 7, and a rear dustproof end plate 9 is provided on the outer side of the rear insulating end plate 8. Both the front dustproof end plate 6 and the rear dustproof end plate 9 include a circular cover 9-2 and several isolation plates 9-1. The isolation plates 9-1 are evenly distributed on the inner edge of the circular cover 9-2 and extend axially. During assembly, the isolation plates 9-1 of the front dustproof end plate 6 and the rear dustproof end plate 9 are inserted into the through slots 3-6 from the front and rear ends of the stator core 3-1, respectively. The isolation plates 9-1 of the two dustproof end plates are in contact with each other or have a small gap in the middle of the through slots 3-6. The width of the isolation plates 9-1 is approximately equal to (slightly smaller than) the width of the through slots 3-6 to achieve a clearance fit, thereby completely isolating the winding slot 3-3 from the rotor space 3-5.

[0044] There is a certain air gap between the outer wall of the rotor core 2-1 and the inner wall of the stator core 3-1, which is a necessary condition for the normal operation of the motor. The annular covers 9-2 of the front dustproof end plate 6 and the rear dustproof end plate 9 cover the openings at both ends of the air gap, sealing the two ends of the rotor space 3-5 and preventing dust from entering from the air gap.

[0045] A sealing ring is provided at the rear end of rotor 2. The rear dustproof end plate 9 presses the sealing ring and forms a tight fit with the inner wall of the housing 1 to achieve sealing at the rear end of rotor 2.

[0046] It is worth noting that in this embodiment, the rear end face of the split sealing component (first split sealing component 11 and second split sealing component 12) abuts against the front end face of the front dustproof end plate 6. For example... Figure 8 As shown, when the split sealing component is installed in place, its rear end face contacts the front end face of the annular cover of the front dustproof end plate 6. This axial pressing fit eliminates the assembly gap between the two, preventing dust from seeping in from the connection. At the same time, this fit also helps to press the front dustproof end plate 6 onto the stator core 3-1, improving the overall assembly stability.

[0047] The following is combined Figure 1 and Figure 2 The following describes two implementation methods for the dust cover (i.e., the sealing of the rear dust cover area 9). Figure 1 An embodiment using an EVA foam pad 10-1 is shown, wherein an EVA foam pad 10-1 is placed between the housing 1 and the rear dustproof end plate 9, and the elasticity of the foam material is used to achieve a seal. Figure 2 An embodiment using an O-ring 10-2 is shown, wherein an annular groove is formed on the bottom surface of the rear dustproof end plate 9, and the O-ring 10-2 is embedded in the annular groove. The rear dustproof end plate 9 presses the O-ring 10-2 against the housing 1 to achieve a seal. Both methods can be selected according to actual assembly space and cost requirements.

[0048] The dustproof working principle of this invention is as follows: When the motor is working, the rotor core 2-2 drives the fan blade 4 to rotate at high speed, generating a cooling airflow. The airflow enters the interior of the housing 1 from the air inlet at the rear end of the motor (not shown in the figure). Due to the sealing fit between the rear end of the rotor 2 and the housing 1 with the O-ring rubber ring 10, dust particles cannot enter the rear end of the rotor 2, but can only enter the winding slot 3-3 area of ​​the stator 3 through the hollow protrusion 7-1 on the rear insulating end plate 8. Between the winding slot 3-3 and the rotor space 3-5, due to the blocking of the through slot 3-6 by the isolation plates 9-1 of the front and rear dustproof end plates, dust particles cannot enter the rotor space 3-5, but can only flow forward along the winding slot 3-3. The airflow carries the dust particles through the winding slot 3-3, removes the heat generated by the coil 3-2, and then flows out from the ventilation space 3-4 at the front end of the stator core 3-1, and enters the fan blade 4 area through the air guide hole 5-2 on the wind baffle ring 5. At this point, because the fence portion 13 at the front end of the split-type sealing component extends into the interior of the fan blade 4, forming a labyrinth seal with the inner wall of the fan blade 4, it prevents dust particles in the airflow from further advancing into the front end area of ​​the rotor 2. Finally, the airflow carrying dust particles is thrown out of the casing 1 by the centrifugal fan blade 4, completing the heat dissipation and dust removal process. Throughout the entire process, the rotor space 3-5 remains isolated from external dust, and the permanent magnet rotor core 2-1 does not adsorb any iron dust.

[0049] It should be further noted that the number of split sealing components is not limited to two; it can also be composed of three or more arc-shaped components spliced ​​together circumferentially, as long as they can form a complete ring structure. The components can be divided circumferentially or axially and then spliced ​​together, and those skilled in the art can choose according to the convenience of mold manufacturing and assembly.

[0050] In summary, this invention, by incorporating a split sealing component within the central hole of the windshield ring and extending its enclosure into the fan blades, ensures excellent dustproof performance while avoiding sacrifices in fan blade length, effectively maintaining the fan blades' heat dissipation efficiency. Simultaneously, the split sealing component, in conjunction with the dustproof structure inside the stator, forms a comprehensive dustproof system from the front end to the interior, significantly improving the reliability and service life of the brushless motor in dusty environments. This invention features a simple structure, convenient assembly, and low cost, demonstrating promising prospects for industrial applications.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various improvements, substitutions, and modifications can be made without departing from the spirit and principles of the present invention, and these improvements, substitutions, and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dustproof structure for a brushless motor, comprising a housing (1), a rotor (2), and a stator (3) surrounding the rotor (2), wherein the stator (3) comprises a stator core (3-1) and a plurality of coils (3-2), and the rotor (2) comprises a rotor spindle (2-2) and a rotor core (2-1) disposed within a central rotor space (3-5) of the stator core (3-1), characterized in that, Also includes: A wind baffle (5) is provided at the front end of the stator (3), and a central hole is provided in the center of the wind baffle (5) for the rotor spindle (2-2) to pass through; The fan blade (4) is sleeved on the front end of the rotor spindle (2-2) and located in front of the windshield ring (5); And at least two separate sealing components are disposed in the central hole of the windshield ring (5). The at least two separate sealing components are arranged to form an annular structure in the circumferential direction. The front end of the annular structure forms a fence portion protruding towards the wind blade (4). The fence portion extends at least partially into the interior of the wind blade (4) and cooperates with the wind blade (4) to form a sealing structure at the front end of the rotor.

2. The dustproof structure of the brushless motor according to claim 1, characterized in that, The split sealing component consists of two semi-annular plastic parts, which are arranged opposite each other in the central hole of the windshield ring (5), and their mating surfaces extend axially.

3. The dustproof structure of the brushless motor according to claim 1 or 2, characterized in that, The fence section has a cylindrical structure with an outer diameter smaller than the inner diameter of the fan blade (4). The outer wall of the fence section and the inner wall of the fan blade (4) form a labyrinth seal structure with a gap fit.

4. The dustproof structure of the brushless motor according to claim 3, characterized in that, The outer wall of the enclosure is provided with at least one circumferentially extending rib or groove to enhance the sealing effect of the maze.

5. The dustproof structure of the brushless motor according to claim 1, characterized in that, The rear end of the split sealing component has an installation part, which is in contact with the inner wall of the central hole of the windshield ring (5), and a positioning structure is provided on the outer peripheral surface of the installation part to restrict the axial movement and circumferential rotation of the split sealing component relative to the windshield ring (5).

6. The dustproof structure of the brushless motor according to claim 5, characterized in that, The positioning structure includes a positioning protrusion disposed on the outer peripheral surface of the mounting part and a positioning groove disposed on the inner wall of the central hole of the windshield ring (5), wherein the positioning protrusion and the positioning groove cooperate; or, the positioning structure includes a positioning plane disposed on the outer peripheral surface of the mounting part and a mating plane disposed on the inner wall of the central hole of the windshield ring (5).

7. The dustproof structure of the brushless motor according to claim 1, characterized in that, The fan blade (4) is a centrifugal fan blade, which includes a blade section and a hub section. The inner ring of the hub section is fitted onto the rotor spindle (2-2), and the fence section extends into the inner space of the hub section.

8. The dustproof structure of the brushless motor according to claim 1, characterized in that, It also includes a front dustproof end plate (6) and a rear dustproof end plate (9). The front dustproof end plate (6) is disposed at the front end of the stator core (3-1), and the rear dustproof end plate (9) is disposed at the rear end of the stator core (3-1). The front dustproof end plate (6) and the rear dustproof end plate (9) respectively include a circular cover (9-2) and a number of isolation plates (9-1). The isolation plates (9-1) are inserted into the through slot (3-6) on the stator core (3-1) that connects the winding slot (3-3) and the rotor space (3-5) to isolate the winding slot (3-3) from the rotor space (3-5).

9. The dustproof structure of the brushless motor according to claim 8, characterized in that, The rear end face of the split sealing component abuts against the front end face of the front dustproof end plate (6) to form an axial pressing fit.

10. The dustproof structure of the brushless motor according to claim 1, characterized in that, The split sealing component is made of an elastic material, and it forms an elastic interference fit with the inner wall of the central hole of the windshield ring (5); or, the split sealing component is made of a rigid material, and a sealing gasket is provided between it and the inner wall of the central hole of the windshield ring (5).

Images