Permanent magnet variable frequency motor self-heat dissipation structure based on industrial fan

Abstract

This invention provides a self-cooling structure for a permanent magnet variable frequency motor based on an industrial fan, relating to the field of industrial fan motor heat dissipation. It includes an inner suction fan blade, an outer exhaust fan blade, and a rotor. The key feature is that the inner suction fan blade can slide along the axial direction of the rotor and is coaxially arranged in opposite directions with the outer exhaust fan blade. A pressure chamber is formed between the inner and outer exhaust fan blades. The inner suction fan blade directionally draws high-temperature gas around the rotor into the pressure chamber, while the outer exhaust fan blade forms a dynamic air seal for pressurization on its inner side and directionally exhausts gas from its outer side. This self-cooling structure for a permanent magnet variable frequency motor based on an industrial fan, through the coaxial and opposite arrangement of the inner and outer exhaust fan blades, combined with the pressurization effect of the pressure chamber, allows the inner suction fan blade to directionally draw in high-temperature gas around the rotor, while the outer exhaust fan blade forms a dynamic air seal on its inner side to constrain the airflow and maintain pressurization, and directionally exhausts gas from its outer side, significantly improving heat dissipation efficiency and air pressure.

Description

Technical Field

[0001] This invention relates to the field of heat dissipation for industrial fan motors, specifically to a self-heating structure for a permanent magnet variable frequency motor based on an industrial fan. Background Technology

[0002] Permanent magnet variable frequency motors are widely used in large ventilation equipment such as industrial fans due to their advantages of high efficiency, energy saving, wide speed range, and stable operation. When an industrial fan is running, the core components of the motor, such as the rotor and stator, continuously generate a large amount of heat. If the heat cannot be dissipated in time, the internal temperature of the motor will rise, which will affect the magnetic properties of the permanent magnets and the insulation performance of the windings, shorten the service life of the motor, and even cause motor overload, burnout, and other failures, seriously affecting the normal operation of the industrial fan. Currently, the built-in heat dissipation structure of permanent magnet variable frequency motors used in industrial fans mostly adopts a single fan blade exhaust design. The fan blade position is fixed, which can only achieve simple air transport and cannot pressurize the airflow. This results in problems such as low heat dissipation efficiency and insufficient air pressure. Especially under high load and high heat generation conditions of the motor, it is unable to quickly expel the high-temperature gas generated by the core components. Furthermore, the fan blade position cannot be adaptively adjusted according to changes in motor speed, leading to insufficient heat dissipation under high load and energy waste under low load. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a self-heating structure for a permanent magnet variable frequency motor based on an industrial fan, which solves the problem of the inability to quickly expel high-temperature gases generated by core components.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution: a self-heating structure for a permanent magnet variable frequency motor based on an industrial fan, comprising an inner ring exhaust fan blade, an outer ring exhaust fan blade, and a rotor, wherein the inner ring exhaust fan blade can slide along the axial direction of the rotor and is arranged coaxially and in opposite directions with the outer ring exhaust fan blade. A pressure chamber is formed between the inner ring exhaust fan blade and the outer ring exhaust fan blade. The inner ring exhaust fan blade draws the high-temperature gas around the rotor into the pressure chamber in a directional manner. The outer ring exhaust fan blade forms a dynamic air seal pressurization on the inner side and exhausts gas in a directional manner on the outer side. When the inner exhaust fan blades move closer to the outer exhaust fan blades, the pressure chamber volume decreases, the airflow constraint increases, the compression degree increases, and the air pressure in the pressure chamber rises, forming a high-pressure output mode. When the inner exhaust fan blades move further away from the outer exhaust fan blades, the pressure chamber volume increases, the airflow constraint weakens, the compression degree decreases, and the air pressure in the pressure chamber decreases, forming a high-volume output mode.

[0005] Preferably, it also includes a housing, the rotor being rotatably disposed inside the housing, and one end of the rotor passing through one side of the housing and rotatably engaging with the housing.

[0006] Preferably, the inner wall of the housing is provided with a mounting bracket, and the inside of the mounting bracket is provided with a stator, and the stator and rotor are coaxially arranged.

[0007] Preferably, the outer surface of the rotor is provided with a keyway, and the inner ring exhaust fan blade is slidably disposed on the rotor through the keyway, and the inner ring exhaust fan blade is coaxial with the rotor.

[0008] Preferably, one end of the stator is provided with a mounting ring, the outer ring exhaust fan blade is rotatably connected to one end of the mounting ring, and the outer ring exhaust fan blade is coaxial with the rotor. The inner ring of the outer ring exhaust fan blade is provided with a plurality of exhaust ports communicating with the pressure chamber for discharging the pressurized airflow.

[0009] Preferably, the outer surface of the inner ring exhaust fan blade is rotatably connected to a collecting plate, and the surface of the collecting plate is provided with a plurality of grooves for collecting high-temperature gas around the rotor.

[0010] Preferably, one end of the outer casing is provided with an adjustment box, and a motion frame is slidably connected inside the adjustment box. One end of the motion frame extends through the outer casing and into the interior to be fixedly connected to the air collecting plate, which is used to drive the air collecting plate and the inner ring exhaust fan blades to slide along the rotor axis.

[0011] Preferably, a spring is provided between the motion frame and the outer shell. The spring is sleeved on the outside of the motion frame to provide elastic restoring force. In conjunction with the air pressure driving force of the inner ring exhaust fan blade, the inner ring exhaust fan blade can achieve stepless sliding and position adjustment with the rotor speed.

[0012] Preferably, an exhaust groove is provided on the right side of the outer surface of the outer shell. The exhaust groove is arranged in a circle and corresponds to the outer exhaust direction of the outer ring exhaust fan blades, and is used to discharge the high-temperature airflow led out by the outer ring exhaust fan blades.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This self-cooling structure for a permanent magnet variable frequency motor based on an industrial fan uses an inner ring suction fan blade and an outer ring exhaust fan blade arranged coaxially and in opposite directions. Combined with the pressurization effect of the pressure chamber, the inner ring suction fan blade draws in high-temperature gas around the rotor in a directional manner, while the outer ring exhaust fan blade forms a dynamic air seal on the inside to constrain the airflow and maintain pressurization, and exhausts the gas in a directional manner on the outside. This significantly improves heat dissipation efficiency and air pressure, solving the problems of insufficient heat dissipation and insufficient air pressure in existing structures.

[0014] This permanent magnet variable frequency motor self-cooling structure based on an industrial fan features an inner ring exhaust fan blade that can slide steplessly along the rotor axis and adaptively adjust its position according to changes in rotor speed. This allows for continuous adjustment of the pressure chamber volume and internal air pressure, enabling switching between high-pressure and high-volume cooling modes. Under high load, it provides high-pressure forced exhaust, while under low load, it operates quietly and energy-savingly. This adapts to different operating conditions of the motor, avoids energy waste, and improves the stability of motor operation.

[0015] This self-heating structure of the permanent magnet variable frequency motor based on industrial fans achieves passive adaptive adjustment of the inner ring exhaust fan blades through the cooperation of spring and air pressure driving force. It requires no additional sensors, electronic control components and power source, and has a simple structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the overall cross-sectional structure of the present invention; Figure 3 This is a schematic diagram of the rotor structure of the present invention; Figure 4 This is a schematic diagram of the stator structure of the present invention; Figure 5 This is a schematic diagram of the motion frame structure of the present invention; Figure 6 This is a schematic diagram of the outer ring exhaust fan blade structure of the present invention; Figure 7 This is a schematic diagram of the cross-sectional structure of the pressure chamber of the present invention; Figure 8 This is a schematic diagram of the inner ring exhaust fan blade structure of the present invention.

[0017] Among them, 1. Inner ring exhaust fan blade; 2. Outer ring exhaust fan blade; 3. Rotor; 4. Housing; 5. Stator; 6. Collector plate; 7. Adjustment box; 8. Motion frame; 9. Mounting frame; 10. Keyway; 11. Mounting ring; 12. Pressure chamber; 13. Exhaust port; 14. Groove; 15. Spring; 16. Exhaust groove. Detailed Implementation

[0018] like Figures 1-8 As shown, a self-cooling structure for a permanent magnet variable frequency motor based on an industrial fan includes an inner ring exhaust fan blade 1, an outer ring exhaust fan blade 2, and a rotor 3. When in use, the inner ring exhaust fan blade 1 is used to extract hot air near the rotor 3, and the outer ring exhaust fan blade 2 is used to quickly expel the collected hot air. The rotor 3 provides power for the rotation of the inner ring exhaust fan blade 1. The inner ring exhaust fan blade 1 can slide along the axial direction of the rotor 3 and is arranged coaxially and in opposite directions with the outer ring exhaust fan blade 2.

[0019] A pressure chamber 12 is formed between the inner ring exhaust fan blade 1 and the outer ring exhaust fan blade 2. When the inner ring exhaust fan blade 1 rotates, it generates axial negative pressure, which draws the high-temperature gas around the rotor 3 into the pressure chamber 12 in a directional manner. The blades in the inner region of the outer ring exhaust fan blade 2 are tilted in a direction opposite to the radial outward direction of the airflow in the pressure chamber 12, forming a dynamic air seal to constrain the airflow and maintain pressurization. The blades in the outer region are tilted in a direction consistent with the axial exhaust direction, which directs the pressurized airflow outward.

[0020] The axial displacement of the inner ring exhaust fan blade 1 along the rotor 3 is determined by the dynamic balance between the air pressure driving force and the elastic restoring force. It slides continuously and steplessly with the change of the rotor 3 speed, realizing the smooth and continuous adjustment of the volume of the pressure chamber 12 and the air pressure inside the chamber, thereby completing the adaptive switching of the heat dissipation mode. When the inner ring exhaust fan blade 1 moves closer to the outer ring exhaust fan blade 2, the volume of the pressure chamber 12 decreases, the airflow constraint is enhanced, the degree of compression is increased, and the air pressure inside the pressure chamber 12 increases, forming a high-pressure output mode. When the inner ring exhaust fan blade 1 moves away from the outer ring exhaust fan blade 2, the volume of the pressure chamber 12 increases, the airflow constraint is weakened, the degree of compression is reduced, and the air pressure inside the pressure chamber 12 decreases, forming a large air volume output mode.

[0021] It also includes a housing 4, and a rotor 3 is rotatably mounted inside the housing 4 via a bearing. One end of the rotor 3 passes through one side of the housing 4 and is rotatably fitted with the housing 4. The bearing, housing 4, and rotor 3 are all interference fits to ensure that the rotor 3 rotates smoothly and that the radial offset meets the design requirements.

[0022] The inner wall of the outer casing 4 is fixed with a mounting bracket 9 by bolts. The mounting bracket 9 is a ring frame structure used to stably support the stator 5. The stator 5 is located inside the mounting bracket 9, and the stator 5 and the rotor 3 are coaxially arranged. The stator 5 is the fixed winding component of the permanent magnet variable frequency motor. After being energized, it can generate a rotating magnetic field. The stator 5 and the rotor 3 are coaxially arranged, and a uniform air gap is left between them to ensure that the rotating magnetic field generated by the stator 5 can stably drive the rotor 3 to rotate. At the same time, the heat generated by the stator 5 during operation can be quickly conducted to the heat dissipation structure through the surrounding airflow to achieve heat dissipation.

[0023] A keyway 10 is provided on the outer surface of the rotor 3. The inner ring exhaust fan blade 1 is slidably mounted on the rotor 3 through the keyway 10, and the inner ring exhaust fan blade 1 is coaxial with the rotor 3. The length of the keyway 10 is adapted to the effective axial length of the rotor 3. A key block matching the keyway 10 is provided at the center hole of the inner ring exhaust fan blade 1. The inner ring exhaust fan blade 1 is slidably mounted on the rotor 3 through the clearance fit between the keyway 10 and the key block. The core function of the keyway 10 is to restrict the circumferential rotation of the inner ring exhaust fan blade 1, ensuring that the inner ring exhaust fan blade 1 and the rotor 3 remain coaxial and rotate synchronously, while allowing the inner ring exhaust fan blade 1 to slide freely and smoothly along the axial direction of the rotor 3, ensuring the stability of the air intake direction of the inner ring exhaust fan blade 1 and avoiding the impact of circumferential offset on the air extraction efficiency.

[0024] One end of the stator 5 is provided with a mounting ring 11. The mounting ring 11 is a ring structure, and its inner diameter is adapted to the outer diameter of the outer ring exhaust fan blade 2. It is used to provide stable rotational support for the outer ring exhaust fan blade 2. The outer ring exhaust fan blade 2 is rotatably connected to one end of the mounting ring 11, and the outer ring exhaust fan blade 2 is coaxial with the rotor 3. The inner ring of the outer ring exhaust fan blade 2 has several exhaust ports 13 that communicate with the pressure chamber 12 to discharge the pressurized airflow. The outer ring exhaust fan blade 2 has an independent power supply and can rotate freely. It can also be rotated by wind force. The outer ring exhaust fan blade 2 and the rotor 3 are kept coaxial to avoid airflow turbulence caused by coaxiality deviation.

[0025] An air collecting plate 6 is rotatably connected to the outer surface of the inner ring exhaust fan blade 1. The surface of the air collecting plate 6 is provided with several grooves 14 for gathering high-temperature gas around the rotor 3. The grooves 14 are used to quickly gather the high-temperature gas dispersed around the rotor 3 and stator 5 to the suction end of the inner ring exhaust fan blade 1, reduce the diffusion of high-temperature gas, significantly improve the suction efficiency of the inner ring exhaust fan blade 1, and ensure that the heat generated by the core components of the motor can be quickly sucked into the pressure chamber 12.

[0026] An adjustment box 7 is provided at one end of the outer casing 4. A motion frame 8 is slidably connected inside the adjustment box 7, and one end of the motion frame 8 extends through the outer casing 4 and into the interior to be fixedly connected to the air collecting plate 6, which is used to drive the air collecting plate 6 and the inner ring exhaust fan blade 1 to slide along the rotor 3 axis.

[0027] A spring 15 is installed between the motion frame 8 and the outer casing 4. The spring 15 is sleeved on the outside of the motion frame 8 to provide an elastic restoring force. This spring, in conjunction with the air pressure driving force of the inner ring exhaust fan blade 1, enables the stepless sliding and position adjustment of the inner ring exhaust fan blade 1 according to the rotational speed of the rotor 3. Initially, the spring 15 is in a slightly compressed state to provide a stable elastic restoring force. This spring 15, together with the air pressure driving force generated when the inner ring exhaust fan blade 1 rotates, forms a stepless adjustment mechanism for the inner ring exhaust fan blade 1. When the air pressure driving force is greater than the elastic restoring force of the spring 15, it pushes the motion frame 8 to slide, causing the inner ring exhaust fan blade 1 to move closer to the outer ring exhaust fan blade 2. When the air pressure driving force is less than the elastic restoring force, the spring 15 returns to its original shape, pushing the motion frame 8 to its original position, causing the inner ring exhaust fan blade 1 to move away from the outer ring exhaust fan blade 2. Ultimately, this achieves stepless sliding and precise position adjustment of the inner ring exhaust fan blade 1 according to the rotational speed of the rotor 3, ensuring adaptive switching of the heat dissipation mode.

[0028] An exhaust groove 16 is provided on the right side of the outer surface of the outer casing 4. The exhaust groove 16 is arranged in a circle and corresponds to the outer exhaust direction of the outer ring exhaust fan blade 2. It is used to discharge the high-temperature airflow that is led out by the outer ring exhaust fan blade 2.

[0029] When in use, after the motor starts, the stator 5 is energized to drive the rotor 3 to rotate. The rotor 3 drives the inner ring exhaust fan blade 1 to rotate synchronously. When the inner ring exhaust fan blade 1 rotates, it generates axial negative pressure. The air collecting plate 6 gathers the high-temperature gas around the rotor 3 through the groove 14 on its surface and draws it into the pressure chamber 12 between the inner ring exhaust fan blade 1 and the outer ring exhaust fan blade 2.

[0030] The outer ring exhaust fan blade 2 starts to rotate, and its inner area forms a dynamic air seal, which constrains the airflow in the pressure chamber 12 and prevents the airflow from leaking out radially. This allows the airflow to continuously accumulate and compress within the pressure chamber 12, achieving pressurization. The pressurized airflow is then discharged to the outside through the exhaust port 13 of the inner ring of the outer ring exhaust fan blade 2, and then discharged to the outside of the outer casing 4 through the exhaust groove 16 on the outer casing 4, completing one heat dissipation cycle.

[0031] As the motor load increases and the rotor speed of 3 rises, the rotational speed of the inner ring exhaust fan blade 1 also increases synchronously, enhancing the suction force. This raises the air pressure in the pressure chamber 12 and at the rear end of the inner ring exhaust fan blade 1. The resulting air pressure driving force overcomes the elastic restoring force of the spring 15, pushing the motion frame 8 to slide along the adjustment box 7. This, in turn, drives the air collecting plate 6 and the inner ring exhaust fan blade 1 to move axially along the rotor 3 towards the outer ring exhaust fan blade 2. At this time, the volume of the pressure chamber 12 continuously decreases, airflow constraint strengthens, and the degree of compression increases. The air pressure inside the chamber continues to rise, forming a high-pressure output mode. This effectively overcomes airflow resistance and quickly discharges the large amount of high-temperature gas generated by the high motor load, ensuring effective heat dissipation.

[0032] When the motor load decreases and the rotor speed of 3 decreases, the suction force of the inner ring exhaust fan blade 1 weakens, and the air pressure in the pressure chamber 12 and at the rear end of the inner ring exhaust fan blade 1 decreases. The air pressure driving force is less than the elastic restoring force of the spring 15, and the spring 15 returns to its deformation, pushing the motion frame 8 to reset, and causing the air collecting plate 6 and the inner ring exhaust fan blade 1 to move away from the outer ring exhaust fan blade 2 along the rotor 3 axis. At this time, the volume of the pressure chamber 12 continues to increase, the airflow constraint weakens, the degree of compression decreases, the air pressure in the chamber continues to decrease, the gas flow resistance decreases, forming a large air volume output mode, achieving efficient and quiet ventilation, and taking into account both heat dissipation efficiency and quiet effect.

[0033] When the rotor 3 speed is stable, the air pressure driving force of the inner ring exhaust fan blade 1 and the elastic restoring force of the spring 15 reach dynamic balance. The inner ring exhaust fan blade 1 is stationary at the current axial position. The volume of the pressure chamber 12 and the air pressure inside the chamber remain constant. The device works stably in the heat dissipation mode corresponding to the current working condition, realizing stepless adaptation under all working conditions.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A permanent magnet variable frequency motor self-cooling structure based on an industrial fan, comprising an inner circle air suction fan blade (1), an outer circle air exhaust fan blade (2) and a rotor (3), characterized in that: The inner ring exhaust fan blade (1) can slide along the axial direction of the rotor (3) and is arranged coaxially and in the opposite direction to the outer ring exhaust fan blade (2). A pressure chamber (12) is formed between the inner ring exhaust fan blade (1) and the outer ring exhaust fan blade (2). The inner ring exhaust fan blade (1) draws the high-temperature gas around the rotor (3) into the pressure chamber (12) in a directional manner. The outer ring exhaust fan blade (2) forms a dynamic air seal pressurization on the inner side and exhausts gas in a directional manner on the outer side. When the inner ring exhaust fan blade (1) moves closer to the outer ring exhaust fan blade (2), the volume of the pressure chamber (12) decreases, the airflow constraint is strengthened, the degree of compression is increased, and the air pressure in the pressure chamber (12) rises, forming a high-pressure output mode; when the inner ring exhaust fan blade (1) moves further away from the outer ring exhaust fan blade (2), the volume of the pressure chamber (12) increases, the airflow constraint is weakened, the degree of compression is reduced, and the air pressure in the pressure chamber (12) decreases, forming a large air volume output mode.

2. The self-heating structure of a permanent magnet variable frequency motor based on an industrial fan according to claim 1, characterized in that: It also includes a housing (4), the rotor (3) is rotatably disposed inside the housing (4), and one end of the rotor (3) passes through one side of the housing (4) and rotates in cooperation with the housing (4).

3. The self-heating structure of a permanent magnet variable frequency motor based on an industrial fan according to claim 2, characterized in that: The inner wall of the outer casing (4) is provided with a mounting bracket (9), and the inside of the mounting bracket (9) is provided with a stator (5), and the stator (5) and the rotor (3) are coaxially arranged.

4. The self-heating structure of a permanent magnet variable frequency motor based on an industrial fan according to claim 2, characterized in that: The outer surface of the rotor (3) is provided with a keyway (10), and the inner ring exhaust fan blade (1) is slidably disposed on the rotor (3) through the keyway (10), and the inner ring exhaust fan blade (1) is coaxial with the rotor (3).

5. The self-heating structure of a permanent magnet variable frequency motor based on an industrial fan according to claim 3, characterized in that: One end of the stator (5) is provided with an installation ring (11), the outer ring exhaust fan blade (2) is rotatably connected to one end of the installation ring (11), and the outer ring exhaust fan blade (2) is coaxial with the rotor (3). The inner ring of the outer ring exhaust fan blade (2) is provided with several exhaust ports (13) that communicate with the pressure chamber (12) for discharging the pressurized airflow.

6. The self-heating structure of a permanent magnet variable frequency motor based on an industrial fan according to claim 4, characterized in that: The outer surface of the inner ring exhaust fan blade (1) is rotatably connected to a collecting plate (6), and the surface of the collecting plate (6) is provided with several grooves (14) for collecting high-temperature gas around the rotor (3).

7. The self-heating structure for a permanent magnet variable frequency motor based on an industrial fan according to claim 6, characterized in that: One end of the outer shell (4) is provided with an adjustment box (7), and a motion frame (8) is slidably connected inside the adjustment box (7). One end of the motion frame (8) extends through the outer shell (4) and into the interior to be fixedly connected to the air collecting plate (6), which is used to drive the air collecting plate (6) and the inner ring exhaust fan blade (1) to slide along the rotor (3) axis.

8. The self-heating structure of a permanent magnet variable frequency motor based on an industrial fan according to claim 7, characterized in that: A spring (15) is provided between the motion frame (8) and the outer shell (4). The spring (15) is sleeved on the outside of the motion frame (8) to provide elastic restoring force. In conjunction with the air pressure driving force of the inner ring exhaust fan blade (1), the inner ring exhaust fan blade (1) can slide and adjust its position with the rotation speed of the rotor (3).

9. A self-heating structure for a permanent magnet variable frequency motor based on an industrial fan according to claim 2, characterized in that: An exhaust groove (16) is provided on the right side of the outer surface of the outer shell (4). The exhaust groove (16) is arranged in a circle and corresponds to the outer exhaust direction of the outer ring exhaust fan blade (2). It is used to discharge the high temperature airflow that is discharged through the outer ring exhaust fan blade (2).

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