A pool cleaner brushless motor

Abstract

The utility model relates to a kind of swimming pool cleaning machine brushless motor, comprising: rotor assembly, including rotor body and magnetic ring, the magnetic ring is wrapped in the rotor body by integral forming;Stator assembly, including stator core, wire holder and winding, the stator core has several teeth slots, the wire holder is configured in the teeth slot, the winding is wound on the wire holder, the middle part of the stator assembly forms mounting hole, the rotor assembly is located in the mounting hole;Hall plate assembly, the Hall plate assembly is located at the rear end of the stator core;Housing, the housing has installation cavity, the rotor assembly, the stator assembly and the Hall plate assembly are located in the installation cavity, the stator assembly and the housing have sealing glue between.

Description

Technical Field

[0001] This utility model relates to the field of motor manufacturing and waterproofing engineering technology, and in particular to a brushless motor for a swimming pool cleaner. Background Technology

[0002] With the continuous improvement of people's living standards and the increasing demand for cleanliness in their living environments, automated swimming pool cleaning equipment, especially swimming pool cleaning robots, is gradually becoming the mainstream choice for modern swimming pool maintenance due to its ability to efficiently and conveniently clean the bottom, walls, and surface of the pool. As the core power component of swimming pool cleaning robots, the performance of their propulsion system directly determines the robot's cleaning efficiency, operational stability, and service life.

[0003] Currently, high-performance pool cleaning robots generally use brushless DC motors (BLDC) as their drive motors. Compared with traditional brushed motors, brushless motors have significant advantages such as high efficiency, high power density, precise speed control, long lifespan, and maintenance-free operation, making them very suitable as underwater propulsion power sources.

[0004] However, since pool cleaning robots need to work continuously in a water-filled environment for a long time, their drive motors must have extremely high waterproof, leak-proof, and corrosion-resistant capabilities, which poses a severe challenge to the design and manufacturing of the motors.

[0005] In existing technologies, common waterproofing measures mainly include: 1. Mechanical seals: using seals such as oil seals and O-rings at the motor shaft protrusion to prevent water from seeping in from the rotating shaft. This method is effective initially, but the seals are vulnerable parts. After long-term underwater operation, pressure changes, and chemical corrosion, they are prone to aging, wear, or deformation, leading to seal failure. 2. Housing seals: fixing the motor housing to the front and rear end covers through threaded connections or snap-fit ​​structures, and using sealing rings (such as O-rings) at the mating surfaces to achieve static sealing. However, the seams of the housing, screw holes, and lead wire outlets are still potential points of water leakage risk. 3. Local protection: impregnating the stator windings with varnish or coating electronic components to improve their moisture resistance. However, these methods provide limited protection and are difficult to cope with the harsh environment of long-term complete immersion. The above-mentioned traditional waterproofing technologies have obvious limitations: they mostly rely on the integrity of physical seals, and these seals have a limited lifespan. Once they fail, moisture can penetrate into the motor. Once moisture enters, it will cause: Electrical failures: short circuits in the winding coils and decreased insulation resistance, potentially leading to motor burnout. Component corrosion: corrosion of precision electronic components such as Hall sensors and circuit board solder joints, resulting in control malfunctions. Magnet degradation: especially for high-performance neodymium iron boron permanent magnets, chloride ions in water will accelerate their oxidation and corrosion, leading to permanent decay of magnetic properties and a decrease in motor output torque. Bearing damage: moisture entering the bearings can cause lubrication failure and corrosion, causing rotor jamming or abnormal noise. Therefore, existing waterproofing technologies are insufficient to meet the requirements of pool cleaning robots for ultra-long motor lifespan (typically several years) and high reliability. An innovative process that can fundamentally solve the waterproofing problem of underwater motors is urgently needed. Summary of the Invention

[0006] In view of the above situation, in order to solve the problems of short circuits in windings, magnet corrosion, electronic component failure and aging of seals caused by water intrusion when the brushless motor of the pool cleaner is working underwater for a long time, it is necessary to propose a brushless motor for pool cleaner with high reliability and long life waterproof performance.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a brushless motor for a swimming pool cleaning machine, comprising: The rotor assembly includes a rotor body and a magnetic ring, wherein the magnetic ring is integrally molded and enclosed within the rotor body; A stator assembly includes a stator core, a wire frame, and windings. The stator core has a plurality of slots, the wire frame is disposed in the slots, the windings are wound on the wire frame, a mounting hole is formed in the middle of the stator assembly, and the rotor assembly is located in the mounting hole. Hall plate assembly, the Hall plate assembly being located at the rear end of the stator core; The housing has a mounting cavity, in which the rotor assembly, the stator assembly, and the Hall plate assembly are all located. The stator assembly and the housing are sealed with adhesive.

[0008] Furthermore, the rotor body has a front bearing at its front end and a rear bearing at its rear end.

[0009] Furthermore, the front end of the housing is provided with a front cover, and the rear end of the housing is provided with a rear cover. The front cover has a first protrusion extending into the mounting cavity, and the inner side of the first protrusion has a front bearing groove, in which the front bearing is disposed. The rear cover has a second protrusion extending into the mounting cavity, and the inner side of the second protrusion has a rear bearing groove, in which the rear bearing is disposed.

[0010] Furthermore, both the front cover and the rear cover are locked to the housing by radial screws.

[0011] Furthermore, both the front bearing groove and the rear bearing groove are stepped grooves.

[0012] Furthermore, the rotor body is hollow, and the rear end of the rotor body has an inner fan blade assembly.

[0013] Furthermore, the inner fan blade assembly includes a plurality of fan blades arranged in a ring array, the fan blades extending from the inner wall of the rotor body toward the center, and the fan blades extending obliquely on the inner wall of the rotor body.

[0014] Furthermore, the ends of the wind blades have arc-shaped flaps.

[0015] Furthermore, there is a gap between adjacent wind blades in an axial view.

[0016] The beneficial effects of this invention are as follows: A permanent magnet ring is used as an insert and integrally encapsulated within the rotor body via injection molding, forming a composite rotor assembly where the magnet ring and the plastic rotor body are seamlessly integrated. This rotor body constitutes the first permanent waterproof and corrosion-resistant barrier for the rotor, isolating corrosive media at the source. A sealant is applied between the stator assembly and the housing, completely filling the annular gap between the stator core and the inner wall of the housing, the gaps between coil turns, and the area around the Hall plate. The sealant cures at room temperature or under heating conditions, forming a robust, seamless, and insulating integral seal that thoroughly seals all electrical and electronic components, constituting the final waterproof layer of the stator. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a brushless motor for a swimming pool cleaner according to an embodiment of the present invention; Figure 2This is a schematic diagram of the internal structure of a brushless motor for a pool cleaning machine according to an embodiment of this utility model; Figure 3 This is a cross-sectional structural schematic diagram of a brushless motor for a pool cleaning machine according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the housing of a brushless motor for a pool cleaning machine according to an embodiment of the present invention.

[0018] Label Explanation: 100. Rotor assembly; 110. Rotor body; 120. Magnetic ring; 130. Front bearing; 140. Rear bearing; 150. Inner fan blade assembly; 151. Fan blade; 1511. Arc-shaped fin; 200. Stator assembly; 201. Mounting hole; 210. Stator core; 220. Wire frame; 300. Hall plate assembly; 400. Housing; 410. Mounting cavity; 420. Control box; 430. Axial limiting rib; 440. Circumferential limiting rib; 500, Sealing compound; 610, Front end cap; 611, First protrusion; 612, Front bearing groove; 620, Rear end cap; 621. Second protrusion; 622. Rear bearing groove. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description of a brushless motor for a swimming pool cleaning machine, in conjunction with the accompanying drawings and embodiments, is provided. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the scope of the utility model.

[0020] Please refer to Figures 1-4 A brushless motor for a pool cleaner, comprising: The rotor assembly 100 includes a rotor body 110 and a magnetic ring 120, wherein the magnetic ring 120 is integrally molded and wrapped inside the rotor body 110. The stator assembly 200 includes a stator core 210, a wire frame 220, and a winding. The stator core 210 has a plurality of slots, the wire frame 220 is disposed in the slots, and the winding is wound on the wire frame 220. A mounting hole 201 is formed in the middle of the stator assembly 200, and the rotor assembly 100 is located in the mounting hole 201. Hall plate assembly 300 is located at the rear end of stator core 210; typically, Hall plate assembly 300 is supported and fixed on wire frame 220. The housing 400 has a mounting cavity 410 inside, and the rotor assembly 100, stator assembly 200 and Hall plate assembly 300 are all located in the mounting cavity 410. There is a sealant 500 between the stator assembly 200 and the housing 400.

[0021] The permanent magnet ring 120 is used as an insert and is integrally encapsulated within the rotor body 110 through injection molding, forming a composite rotor assembly 100 in which the magnet ring 120 and the plastic rotor body 110 are seamlessly integrated. This rotor body 110 constitutes the first permanent waterproof and corrosion-resistant barrier of the rotor, isolating corrosive media at the source. A sealant 500 is applied between the stator assembly 200 and the housing 400. The sealant 500 completely fills the annular gap between the stator core 210 and the inner wall of the housing 400, the gaps between coil turns, and the area around the Hall plate. The sealant 500 cures at room temperature or under heating conditions, forming a robust, seamless, and insulating integral seal that completely seals all electrical and electronic components, constituting the final waterproof layer of the stator.

[0022] Please refer to Figure 2 and Figure 3 The rotor body 110 has a front bearing 130 at its front end and a rear bearing 140 at its rear end. The front and rear bearings 140 support the rotor body 110 and ensure its smooth rotation. Preferably, both the front bearing 130 and the rear bearing 140 are high-precision ceramic bearings or stainless steel bearings to reduce friction loss and improve energy efficiency.

[0023] Please refer to Figure 1 and Figure 3 The housing 400 has a front cover 610 at its front end and a rear cover 620 at its rear end. The front cover 610 has a first protrusion 611 extending into the mounting cavity 410, and the inner side of the first protrusion 611 has a groove for a front bearing 130, in which the front bearing 130 is disposed. The rear cover 620 has a second protrusion 621 extending into the mounting cavity 410, and the inner side of the second protrusion 621 has a groove for a rear bearing 140, in which the rear bearing 140 is disposed. The first protrusion 611 and the second protrusion 621 can enhance the sealing and connection stability.

[0024] Please refer to Figure 1 and Figure 3 Both the front cover 610 and the rear cover 620 are locked to the housing 400 by radial screws. That is, the radial screws pass through the housing 400 and lock to the first protrusion 611 or the second protrusion 621.

[0025] Please refer to Figure 3 Both the front bearing (slot 130) and the rear bearing (slot 140) are stepped grooves. This reduces the contact area and improves the smoothness of bearing operation.

[0026] Please refer to Figures 1-3 The rotor body 110 is hollow, and its rear end has an inner fan blade assembly 150. The inner fan blade assembly 150 cuts the water flow during rotation, generating axial thrust to propel the pool cleaner forward. It is more compact, safer, and less prone to damage compared to the outer fan blades. Understandably, the inner fan blade assembly 150 is integrally formed with the rotor body 110.

[0027] Please refer to Figure 1 and Figure 3 The inner fan blade assembly 150 includes a plurality of fan blades 151 arranged in a ring array. The fan blades 151 extend from the inner wall of the rotor body 110 toward the center and extend obliquely on the inner wall of the rotor body 110. This enables the inner fan blade assembly 150 to generate axial thrust.

[0028] Please refer to Figure 1 and Figure 3 The end of the blade 151 has an arc-shaped flap 1511. This increases the airflow velocity, thereby increasing the thrust.

[0029] Preferably, there is a gap between adjacent wind blades 151 in the axial view.

[0030] Specifically, a control box 420 is provided on the outer wall of the housing 400. The control box 420 is connected to the mounting cavity 410. The Hall plate assembly 300 and the winding leads are all electrically connected to the outside through the control box 420.

[0031] Understandably, the inner wall of the housing 400 is generally provided with axial limiting ribs 430 and circumferential limiting ribs 440. The axial limiting ribs 430 are supported at the bottom of the stator assembly 200 to facilitate pre-positioning before sealing 500. The circumferential limiting ribs 440 are adapted to the limiting grooves on the outer wall of the stator assembly 200 to prevent the stator assembly 200 from rotating.

[0032] Understandably, the Hall plate assembly 300 is used to provide real-time feedback on the position of the rotor body 110, and works with an external controller to achieve sensor-based control of the brushless motor, optimizing starting torque and operating efficiency.

[0033] Understandably, the magnetic ring 120 is integrally molded within the rotor body 110. First, pre-magnetized or unmagnetized permanent magnets (such as NdFeB, ferrite, etc.) are precisely placed at designated positions in a high-precision injection mold. Then, high-performance thermoplastic engineering plastics (such as nylon PA6, PA66, PPS, PBT, etc., often reinforced with glass fiber) are heated to a molten state and injected into the mold cavity under high pressure. The molten plastic perfectly encapsulates each magnet, filling all gaps within the mold and forming a tight physical bond with the magnet surface, completely encapsulating the outer circumference and axial end face of the permanent magnet ring. After cooling and solidification, the mold is opened, resulting in a composite component where the magnet and the plastic rotor body 110 are seamlessly integrated. The core mechanism for achieving waterproofing lies in the injection-molded plastic rotor body forming a continuous, seamless, and dense physical barrier, completely isolating the internal magnets from the external environment. The thickness and uniformity of this plastic shell are ensured by the mold, effectively resisting water pressure. Even in deep water environments, water molecules have extreme difficulty penetrating this complete plastic coating. Furthermore, by selecting engineering plastics with excellent hydrolysis and chemical corrosion resistance, it resists the erosion of chlorine, bromine, salt, and household cleaning chemicals in pool water, ensuring the long-term stability of the outer shell. Simultaneously, the insulation properties of the plastic eliminate the risk of electrical short circuits caused by water infiltration. The entire rotor assembly 100 becomes a single unit after injection molding, eliminating the need for subsequent bonding or welding processes, avoiding defects and stress concentration points that these processes might introduce, thereby further improving structural integrity and long-term reliability. In summary, completely encapsulating the magnet within the plastic rotor body 110 through injection molding not only simplifies the assembly process and reduces costs, but more importantly, it constructs an indestructible "waterproof Great Wall" for the motor rotor, a core technological guarantee for ensuring the motor's long-term, stable, and efficient operation in harsh underwater environments.

[0034] In contrast, if magnets are mechanically bonded or clipped onto metal or plastic supports, the bonding interface or mechanical gaps become potential channels for water seepage. Under prolonged immersion, moisture can seep in through capillary action or pressure difference, causing magnet oxidation and rust (especially since neodymium iron boron magnets are highly susceptible to corrosion), leading to magnetic performance degradation, rotor imbalance, and ultimately motor failure. Injection molding, however, fundamentally eliminates these interfaces and gaps, achieving IP68 or even higher levels of waterproofing.

[0035] Understandably, the stator assembly 200 and the housing 400 are sealed with an adhesive 500, which means that the entire stator assembly 200 (including the stator core 210, copper winding coils, lead solder joints, Hall plate assembly 300, etc.) is completely immersed and filled in a special liquid polymer material. After curing, it forms a strong, seamless, and dense whole. Commonly used potting materials typically employ materials with excellent insulation, low water absorption, high and low temperature resistance, hydrolysis resistance, and chemical corrosion resistance, including at least one or a combination of epoxy resin, polyurethane, and silicone. The potting process is usually carried out in a vacuum environment to completely eliminate air bubbles and ensure that the adhesive can penetrate into every tiny gap and between coil turns. After curing, this potting layer acts like a "sealed armor" for the stator, and its waterproofing effect is manifested on multiple levels: First, it achieves a physical absolute seal. The potting compound 500 completely fills the annular gap between the stator core 210 and the outer casing, the capillary gaps between the coil wires, the tiny channels at the lead wire exits, and the complex areas surrounding the electronic components. After curing, these "loopholes" that could have become pathways for moisture intrusion are completely blocked, forming a continuous, non-porous protective layer. Even under deep water and high pressure, water molecules have difficulty penetrating this dense barrier, thus achieving IP68 or even higher levels of waterproof protection. Secondly, it provides strong resistance to chemical corrosion. Chlorine and bromine in pool water, salt in seawater, and minerals and chemical additives in industrial water are all highly corrosive. Traditional sealing methods (such as O-rings and sealant 500 strips) may fail due to aging or minor damage. However, the overall potting directly isolates all metal parts (copper wires, iron core) and electronic components from these corrosive media. The potting material itself is chemically stable and not easily hydrolyzed or corroded, thus effectively preventing copper wire oxidation, iron core rusting, solder joint corrosion, and Hall plate failure, fundamentally protecting the core functions of the motor. Furthermore, potting offers multiple additional benefits: it enhances the mechanical strength of the stator, secures the coils, and improves resistance to vibration and shock; it improves heat dissipation (partially thermally conductive potting compound 500 can dissipate heat); it enhances electrical insulation performance and helps reduce electromagnetic noise. In short, stator waterproofing, especially waterproofing achieved through integral potting, is the lifeline of modern high-performance motors, particularly those used in underwater applications. It is not merely a simple protection against water ingress, but a systematic engineering project for building a long-term stable, safe, reliable, and durable power core, and the fundamental guarantee for the motor to continuously "breathe" and "operate" in harsh liquid environments.

[0036] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0037] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0038] In summary, the brushless motor for a pool cleaner provided by this utility model constructs multiple, long-lasting waterproof barriers in terms of materials and structure by injection molding the rotor magnet and encapsulating the stator assembly, completely isolating the core components of the motor from water and corrosive media, thereby significantly improving the reliability and durability of the motor in harsh pool environments.

[0039] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A brushless motor for a swimming pool cleaner, characterized in that, include: The rotor assembly includes a rotor body and a magnetic ring, wherein the magnetic ring is integrally molded and enclosed within the rotor body; A stator assembly includes a stator core, a wire frame, and windings. The stator core has a plurality of slots, the wire frame is disposed in the slots, the windings are wound on the wire frame, a mounting hole is formed in the middle of the stator assembly, and the rotor assembly is located in the mounting hole. Hall plate assembly, the Hall plate assembly being located at the rear end of the stator core; The housing has a mounting cavity, in which the rotor assembly, the stator assembly, and the Hall plate assembly are all located. The stator assembly and the housing are sealed with adhesive.

2. The brushless motor for a swimming pool cleaner according to claim 1, characterized in that, The rotor body has a front bearing at the front end and a rear bearing at the rear end.

3. The brushless motor for a swimming pool cleaner according to claim 2, characterized in that, The front end of the housing is provided with a front cover, and the rear end of the housing is provided with a rear cover. The front cover has a first protrusion extending into the mounting cavity. The inner side of the first protrusion has a front bearing groove, and the front bearing is disposed in the front bearing groove. The rear cover has a second protrusion extending into the mounting cavity. The inner side of the second protrusion has a rear bearing groove, and the rear bearing is disposed in the rear bearing groove.

4. The brushless motor for a swimming pool cleaner according to claim 3, characterized in that, Both the front cover and the rear cover are locked to the housing by radial screws.

5. A brushless motor for a swimming pool cleaner according to claim 3, characterized in that, Both the front bearing groove and the rear bearing groove are stepped grooves.

6. The brushless motor for a swimming pool cleaner according to claim 1, characterized in that, The rotor body is hollow, and the rear end of the rotor body has an inner fan blade assembly.

7. A brushless motor for a swimming pool cleaner according to claim 6, characterized in that, The inner fan blade assembly includes a plurality of fan blades arranged in a ring array. The fan blades extend from the inner wall of the rotor body toward the center and extend obliquely on the inner wall of the rotor body.

8. A brushless motor for a swimming pool cleaner according to claim 7, characterized in that, The ends of the wind blades have arc-shaped flaps.

9. A brushless motor for a swimming pool cleaner according to claim 7, characterized in that, There is a gap between adjacent wind blades in the axial view.

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