A brushless motor for a vacuum cleaner with overload protection function

Abstract

The application discloses a brushless motor with overload protection function for a dust collector, and relates to the technical field of brushless motors.The brushless motor comprises an outer machine box, a motor shell, a main shaft, a permanent magnet rotor, a pair of retainers and a plurality of winding coils.The motor shell is installed on the outer machine box, the main shaft is rotatably installed on the motor shell through a pair of bearings, the permanent magnet rotor is installed on the main shaft, a pair of retainers are arranged in the motor shell, and a plurality of winding coils are annularly and uniformly distributed between the pair of retainers.The main shaft is provided with centrifugal fan blades, the outer machine box is provided with a damping assembly, and the motor shell is provided with a heat dissipation assembly.The torque impact is reduced through a plurality of series-connected speed-increasing linkage gears.The torque required is gradually increased with each backward transmission of the speed-increasing linkage gears, the rigid impact is changed into a flexible impact, the dust collector is prevented from generating vibration, the strength of the connecting structure is protected, and the impact damage is avoided.

Description

Technical Field

[0001] This invention relates to the field of brushless motor technology, specifically a brushless motor for vacuum cleaners with overload protection. Background Technology

[0002] In recent years, as vacuum cleaner filtration systems have evolved towards higher-grade filters such as HEPA / H13, airflow resistance has increased significantly, forcing brushless motors to continuously increase their power density. Current high-end models have reached over 500W. This power increase has led to a sharp deterioration in the motor's thermal load, with winding temperature rise exceeding 60% compared to earlier products. Traditional heat dissipation solutions face fundamental contradictions. Existing motors generally rely on natural convection cooling from the casing, which is inefficient. While adding ventilation holes to the casing can improve heat exchange efficiency, the high concentration of fine dust inside the vacuum cleaner can easily penetrate the motor cavity, causing bearing grease contamination and accelerated wear. The accumulation of conductive dust can lead to armature short circuits. When a high-power brushless motor starts, the transient peak value of the phase current can reach 300% of the rated value, generating strong torque pulsation. Over time, this can lead to fatigue cracking of the connection solder joints, resulting in vibration and abnormal noise throughout the machine. Summary of the Invention

[0003] The purpose of this invention is to provide a brushless motor for a vacuum cleaner with overload protection to solve the problems mentioned in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a brushless motor for a vacuum cleaner with overload protection function, comprising an outer casing, a motor housing, a main shaft, a permanent magnet rotor, a pair of cages, and several winding coils. The motor housing is mounted on the outer casing, the main shaft is rotatably mounted on the motor housing via a pair of bearings, the permanent magnet rotor is mounted on the main shaft, the pair of cages are disposed in the motor housing, the several winding coils are evenly distributed in a ring between the pair of cages, a centrifugal fan blade is mounted on the main shaft, a shock-absorbing component is installed in the outer casing, and a heat dissipation component is disposed in the motor housing.

[0005] Furthermore, the shock absorption assembly includes a gear ring and several speed-increasing linkage gears. The gear ring is disposed on the outer ring of the motor housing and is rotatably mounted inside the outer casing. Each speed-increasing linkage gear is formed by a small gear and a large gear coaxially connected. Each speed-increasing linkage gear is rotatably mounted inside the outer casing. At the moment the brushless motor inside the vacuum cleaner starts, the motor housing is subjected to a reaction torsional force, and the gear ring rotates synchronously with the motor housing, driving the speed-increasing linkage gears to rotate.

[0006] Furthermore, the pinion of one of the speed-increasing linkage gears meshes with the gear ring, and the other speed-increasing linkage gears are connected in sequence. The pinion of the latter speed-increasing linkage gear meshes with the large gear of the former speed-increasing linkage gear. A return torsion spring is provided at the junction of the last speed-increasing linkage gear and the outer casing. The torque required increases with each stage of the speed-increasing linkage gear transmission. The last stage of the speed-increasing linkage gear is constrained by the return torsion spring. The rotation of several speed-increasing linkage gears weakens the reaction torsional force, transforming rigid impact into flexible impact, and preventing the vacuum cleaner from vibrating due to the reverse torsional impact force. After the brushless motor enters normal working state, the reverse torsional impact force decreases, and the return torsion spring drives the last stage of the speed-increasing linkage gear to reverse and reset. The motor housing also rotates and resets. Through the setting of the shock-absorbing component, the torque impact is reduced by several speed-increasing linkage gears connected in series, preventing the vacuum cleaner from vibrating, while protecting the strength of the connection structure and preventing impact damage.

[0007] Furthermore, the heat dissipation assembly includes a sealing ring and several thin rods. The sealing ring is rotatably installed inside the motor housing on the side away from the centrifugal fan blades. Several sliding grooves are evenly distributed in a ring on the motor housing. The sealing ring seals the sliding grooves. Several thin rods are installed on the sealing ring and are slidably installed in each sliding groove. When the brushless motor starts, it drives the centrifugal fan blades to rotate. Airflow flows over the surface of the brushless motor. The air guide vanes increase the contact area with the flowing airflow, thereby enhancing the heat dissipation effect.

[0008] Furthermore, the heat dissipation assembly includes the same number of air guide vanes as the thin rods, with several air guide vanes evenly distributed in a ring on the outer side of the motor housing, and an elastic sheet connecting each thin rod to each air guide vane.

[0009] Furthermore, a through hole is provided on the motor housing, and several inner support blocks are arranged in a ring evenly. A thermally expanding material is placed between each inner support block and the sealing ring. If the internal temperature of the brushless motor gradually increases, the thermally expanding material expands due to heat, pushing the sealing ring to rotate inside the motor housing. When the sealing ring rotates, it causes all the thin rods to deflect in the sliding grooves. The thin rods drive the elastic plates to move. When the elastic plates block the flow channels between the air guide vanes, the airflow velocity across the air guide vanes decreases, forming a [condition] at the tail of the brushless motor. A local high-pressure zone is formed, while the airflow velocity is high and the air pressure is low at the other end of the brushless motor. The air pressure difference is used to allow airflow to ventilate and dissipate heat inside the brushless motor through the through hole. When the internal temperature of the brushless motor decreases, the thermal expansion material contracts, the sealing ring resets, and the elastic sheet also resets. The air duct between the air guides is fully opened. Through the setting of the heat dissipation component, the internal temperature of the brushless motor is cooled down. The airflow through the outside and inside of the brushless motor is adjusted according to the temperature change of the brushless motor to achieve dynamic temperature regulation and avoid the problem of overheating inside the brushless motor.

[0010] Furthermore, a rubber disc is provided on the side of the spindle away from the outer casing, a glass plate and several internal friction blocks are provided on the side of the motor housing near the rubber disc, and several external friction blocks are provided on the side of the rubber disc near the glass plate. Several external friction blocks are in contact with the glass plate, and several internal friction blocks are in contact with the rubber disc.

[0011] Furthermore, both the outer and inner friction blocks are made of fiber material and are evenly distributed in a circumferential shape. When the main shaft rotates at high speed, the inner friction block rubs against the rubber disc, causing negative charges to accumulate on the rubber disc, while the outer friction block rubs against the glass plate, causing positive charges to accumulate on the glass plate. Thus, an electrostatic field is formed between the rubber disc and the glass plate, ionizing the dust in the air and causing the dust in the air to be adsorbed, preventing it from entering the brushless motor with the airflow, thereby achieving the effect of electrostatic dust removal.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] 1. By using several series-connected speed-increasing gears, the torque impact is reduced. The required torque increases with each subsequent drive of the speed-increasing gear, transforming rigid impact into flexible impact, avoiding vibration of the vacuum cleaner, and protecting the strength of the connection structure from impact damage.

[0014] 2. When the spindle rotates at high speed, the inner friction block rubs against the rubber disc, causing negative charges to accumulate on the rubber disc. The outer friction block rubs against the glass plate, causing positive charges to accumulate on the glass plate. As a result, an electrostatic field is formed between the rubber disc and the glass plate, which ionizes the dust in the air. This causes the dust in the air to be adsorbed and will not enter the brushless motor with the airflow, thus achieving the effect of electrostatic dust removal.

[0015] 3. By using thermal expansion material to push the sealing ring to rotate inside the motor housing, the internal temperature of the brushless motor is cooled down. The airflow through the outside and inside of the brushless motor is adjusted according to the temperature change of the brushless motor, achieving dynamic temperature regulation and avoiding the problem of overheating inside the brushless motor. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 ;

[0017] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 2 ;

[0018] Figure 3 This is a schematic diagram of the internal structure of the external chassis of the present invention;

[0019] Figure 4 This is a schematic diagram of the internal structure of the motor housing of the present invention. Figure 1 ;

[0020] Figure 5 This is a schematic diagram of the internal structure of the motor housing of the present invention. Figure 2 ;

[0021] Figure 6 This is a schematic diagram of the internal structure of the motor housing of the present invention. Figure 3 ;

[0022] Figure 7 This is a schematic diagram of the internal structure of the motor housing of the present invention. Figure 4 .

[0023] In the diagram: 1. Outer casing; 2. Motor housing; 3. Main shaft; 4. Permanent magnet rotor; 5. Cage; 6. Winding coil; 7. Bearing; 8. Gear ring; 9. Speed-increasing linkage gear; 10. Through hole; 11. Inner support block; 12. Thermal expansion material; 13. Sealing ring; 14. Slide groove; 15. Thin rod; 16. Elastic sheet; 17. Air guide plate; 18. Outer friction block; 19. Rubber disc; 20. Inner friction block. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example: Figures 1-7 As shown, the present invention provides a technical solution: a brushless motor for a vacuum cleaner with overload protection function, including an outer casing 1, a motor housing 2, a main shaft 3, a permanent magnet rotor 4, a pair of retainers 5, and several winding coils 6. The motor housing 2 is mounted on the outer casing 1, the main shaft 3 is rotatably mounted on the motor housing 2 via a pair of bearings 7, the permanent magnet rotor 4 is mounted on the main shaft 3, the pair of retainers 5 are disposed in the motor housing 2, and several winding coils 6 are evenly distributed in a ring between the pair of retainers 5. A centrifugal fan blade (not shown in the figure) is mounted on the main shaft 3, a shock absorption component is installed in the outer casing 1, and a heat dissipation component is provided in the motor housing 2.

[0026] The shock absorption assembly includes a gear ring 8 and several speed-increasing linkage gears 9. The gear ring 8 is located on the outer ring of the motor housing 2 and is rotatably mounted inside the outer casing 1. Each speed-increasing linkage gear 9 consists of a small gear and a large gear coaxially connected. Each speed-increasing linkage gear 9 is rotatably mounted inside the outer casing 1. The small gear of one speed-increasing linkage gear 9 meshes with the gear ring 8, and the other speed-increasing linkage gears 9 are connected in sequence. The small gear in the latter speed-increasing linkage gear 9 meshes with the large gear in the former speed-increasing linkage gear 9. A return torsion spring is provided at the junction of the last speed-increasing linkage gear 9 and the outer casing 1.

[0027] At the moment the brushless motor inside the vacuum cleaner starts, the motor housing 2 is subjected to a reaction torsional force. The gear ring 8 rotates synchronously with the motor housing 2, driving the speed-increasing linkage gear 9 to rotate. With each subsequent stage of transmission, the required torque increases. The last stage of the speed-increasing linkage gear 9 is constrained by a return torsion spring. The rotation of several speed-increasing linkage gears 9 weakens the reaction torsional force, transforming rigid impact into flexible impact, thus preventing the vacuum cleaner from vibrating due to the reverse torsional impact force. After the brushless motor enters normal working condition, the reverse torsional impact force decreases, and the return torsion spring drives the last stage of the speed-increasing linkage gear 9 to reverse and reset. The motor housing 2 also rotates and resets. Through the setting of the shock-absorbing components, the torque impact is reduced by several speed-increasing linkage gears 9 connected in series, preventing the vacuum cleaner from vibrating and protecting the strength of the connecting structure from impact damage.

[0028] The heat dissipation assembly includes a sealing ring 13 and several thin rods 15. The sealing ring 13 is rotatably installed inside the motor housing 2 on the side away from the centrifugal fan blades. Several sliding grooves 14 are evenly distributed in a ring on the motor housing 2. The sealing ring 13 seals the sliding grooves 14. Several thin rods 15 are installed on the sealing ring 13 and are slidably installed in each sliding groove 14. The heat dissipation assembly includes air guide vanes 17 in the same number as the thin rods 15. Several air guide vanes 17 are evenly distributed in a ring on the outside of the motor housing 2. Each thin rod 15 is connected to each air guide vane 17 by an elastic sheet 16. A through hole 10 is opened on the motor housing 2. Several inner support blocks 11 are arranged in a ring evenly distributed inside the motor housing 2. A thermal expansion material 12 is provided between each inner support block 11 and the sealing ring 13. When the brushless motor starts, it drives the centrifugal fan blades to rotate. Airflow flows over the surface of the brushless motor. The air guide vanes 17 increase the contact area with the flowing airflow and enhance the heat dissipation effect.

[0029] If the internal temperature of the brushless motor gradually increases, the thermal expansion material 12 expands due to heat. The thermal expansion material 12 pushes the sealing ring 13 to rotate inside the motor housing 2. When the sealing ring 13 rotates, it drives all the thin rods 15 to deflect in the slide groove 14. The thin rods 15 drive the elastic plate 16 to move. When the elastic plate 16 blocks the flow channel between the air guide plates 17, the airflow velocity through the air guide plates 17 decreases, forming a local high-pressure area at the tail of the brushless motor. At the other end of the brushless motor, the airflow velocity is fast and the air pressure is low. The air pressure difference allows the airflow to ventilate and dissipate heat inside the brushless motor through the through hole 10. When the internal temperature of the brushless motor decreases, the thermal expansion material 12 contracts, the sealing ring 13 resets, and the elastic plate 16 also resets. The air channel between the air guide plates 17 is fully opened. Through the setting of the heat dissipation component, the internal temperature of the brushless motor is cooled down. The airflow through the outside and inside of the brushless motor is adjusted according to the temperature change of the brushless motor, realizing dynamic temperature regulation and avoiding the problem of overheating inside the brushless motor.

[0030] A rubber disc 19 is provided on the side of the spindle 3 away from the outer casing 1. A glass plate and several internal friction blocks 20 are provided on the side of the motor housing 2 near the rubber disc 19. Several external friction blocks 18 are provided on the side of the rubber disc 19 near the glass plate. The external friction blocks 18 are in contact with the glass plate, and the internal friction blocks 20 are in contact with the rubber disc 19. Both the external friction blocks 18 and the internal friction blocks 20 are made of fiber material and are evenly distributed in a circumferential shape. When the spindle 3 rotates at high speed, the internal friction blocks 20 rub against the rubber disc 19, causing negative charges to accumulate on the rubber disc 19. The external friction blocks 18 rub against the glass plate, causing positive charges to accumulate on the glass plate. Thus, an electrostatic field is formed between the rubber disc 19 and the glass plate, ionizing the dust in the air. This causes the dust in the air to be adsorbed and will not enter the brushless motor with the airflow, achieving the effect of electrostatic dust removal.

[0031] The working principle of this invention is as follows: At the moment the brushless motor inside the vacuum cleaner starts, the motor housing 2 experiences a reaction torsional force. The gear ring 8 rotates synchronously with the motor housing 2, driving the speed-increasing linkage gear 9 to rotate. With each subsequent stage of transmission, the required torque increases. The final stage of the speed-increasing linkage gear 9 is constrained by a return torsion spring. The rotation of several speed-increasing linkage gears 9 weakens the reaction torsional force, transforming rigid impact into flexible impact, thus preventing the vacuum cleaner from vibrating due to the reverse torsional impact. After the brushless motor enters normal operating mode, the reverse torsional impact decreases, and the return torsion spring drives the final stage of the speed-increasing linkage gear 9 to reverse and reset. The motor housing 2 also rotates and resets. Through the shock-absorbing components, the torque impact is reduced by several series-connected speed-increasing linkage gears 9, preventing the vacuum cleaner from vibrating and protecting the strength of the connecting structure from impact damage.

[0032] When the brushless motor starts, it drives the centrifugal fan blades to rotate. Airflow passes over the surface of the brushless motor. The guide vanes 17 increase the contact area with the flowing airflow, enhancing the heat dissipation effect. If the internal temperature of the brushless motor gradually rises, the thermal expansion material 12 expands due to heat. The thermal expansion material 12 pushes the sealing ring 13 to rotate inside the motor housing 2. When the sealing ring 13 rotates, it drives all the thin rods 15 to deflect in the slide groove 14. The thin rods 15 drive the elastic plate 16 to move. When the elastic plate 16 blocks the flow channel between the guide vanes 17, the airflow velocity passing through the guide vanes 17 decreases, forming a cooling effect at the tail of the brushless motor. A local high-pressure zone is formed, while the airflow velocity is high and the air pressure is low at the other end of the brushless motor. The air pressure difference is used to allow airflow to ventilate and dissipate heat inside the brushless motor through the through hole 10. When the internal temperature of the brushless motor decreases, the thermal expansion material 12 contracts, the sealing ring 13 resets, the elastic sheet 16 also resets, and the air duct between the air guides 17 is fully opened. Through the setting of the heat dissipation component, the internal temperature of the brushless motor is cooled down, and the airflow through the outside and inside of the brushless motor is adjusted according to the temperature change of the brushless motor to achieve dynamic temperature regulation and avoid the problem of overheating inside the brushless motor.

[0033] When the spindle 3 rotates at high speed, the inner friction block 20 rubs against the rubber disc 19, causing negative charges to accumulate on the rubber disc 19, and the outer friction block 18 rubs against the glass plate, causing positive charges to accumulate on the glass plate. Thus, an electrostatic field is formed between the rubber disc 19 and the glass plate, ionizing the dust in the air, so that the dust in the air is adsorbed and will not enter the brushless motor with the airflow, achieving the effect of electrostatic dust removal.

[0034] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A brushless motor for a vacuum cleaner with overload protection, characterized in that: The device includes an outer casing (1), a motor housing (2), a main shaft (3), a permanent magnet rotor (4), a pair of cages (5), and several winding coils (6). The motor housing (2) is mounted on the outer casing (1). The main shaft (3) is rotatably mounted on the motor housing (2) via a pair of bearings (7). The permanent magnet rotor (4) is mounted on the main shaft (3). A pair of cages (5) are disposed in the motor housing (2). Several winding coils (6) are evenly distributed in a ring between the pair of cages (5). Centrifugal fan blades are mounted on the main shaft (3). A shock-absorbing component is installed in the outer casing (1). A heat dissipation component is provided in the motor housing (2). The heat dissipation assembly includes a sealing ring (13) and several thin rods (15). The sealing ring (13) is rotatably installed inside the motor housing (2) on the side away from the centrifugal fan blades. Several sliding grooves (14) are evenly distributed in a ring on the motor housing (2). The sealing ring (13) seals the sliding grooves (14). Several thin rods (15) are installed on the sealing ring (13) and are slidably installed in each sliding groove (14). The heat dissipation assembly includes air guides (17) in the same number as the thin rods (15). Several air guides (17) are evenly distributed in a ring on the outside of the motor housing (2). Each thin rod (15) is connected to each air guide (17) by an elastic sheet (16). The motor housing (2) has a through hole (10), and the motor housing (2) has several inner support blocks (11) inside. The several inner support blocks (11) are evenly distributed in a ring, and a thermal expansion material (12) is provided between each inner support block (11) and the sealing ring (13).

2. The brushless motor for a vacuum cleaner with overload protection function according to claim 1, characterized in that: The shock absorption assembly includes a gear ring (8) and several speed-increasing linkage gears (9). The gear ring (8) is set on the outer ring of the motor housing (2). The gear ring (8) is rotatably installed inside the outer casing (1). Each speed-increasing linkage gear (9) is formed by a small gear and a large gear coaxially connected. Each speed-increasing linkage gear (9) is rotatably installed inside the outer casing (1).

3. A brushless motor for a vacuum cleaner with overload protection function according to claim 2, characterized in that: One of the speed-increasing linkage gears (9) has a small gear that meshes with a gear ring (8), and the other speed-increasing linkage gears (9) are connected in sequence. The small gear in the latter speed-increasing linkage gear (9) meshes with the large gear in the former speed-increasing linkage gear (9). A reset torsion spring is provided at the junction of the last speed-increasing linkage gear (9) and the outer casing (1).

4. A brushless motor for a vacuum cleaner with overload protection function according to claim 1, characterized in that: A rubber disc (19) is provided on the side of the main shaft (3) away from the outer casing (1). A glass plate and several internal friction blocks (20) are provided on the side of the motor housing (2) near the rubber disc (19). Several external friction blocks (18) are provided on the side of the rubber disc (19) near the glass plate. Several external friction blocks (18) are in contact with the glass plate, and several internal friction blocks (20) are in contact with the rubber disc (19).

5. A brushless motor for a vacuum cleaner with overload protection function according to claim 4, characterized in that: Both the outer friction block (18) and the inner friction block (20) are made of fiber material, and the outer friction block (18) and the inner friction block (20) are evenly distributed in a circumferential shape.

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