A low-noise mixed-flow fan for high-volume ventilation

Abstract

This application relates to the field of mixed-flow fans and discloses a low-noise mixed-flow fan for large-volume ventilation, including a housing, a motor fixedly installed inside the housing, and fan blades mounted on the output shaft of the motor via a coupling. The housing includes a fixed cylinder and an extension cylinder welded to one side of the fixed cylinder. A long shaft is mounted at the center of the hub of the fan blades, and a magnetic transmission structure for speed reduction is mounted on the outside of the long shaft; the magnetic transmission structure includes a speed-reducing magnetic ring. During dust removal and prevention, the magnetic transmission structure replaces the traditional rigid coupling transmission. Power transmission is achieved through magnetic coupling between the speed-reducing magnetic rings, eliminating frictional noise and vibration generated by mechanical contact. Simultaneously, noise-reducing plates are installed on the inner wall of the fan, utilizing rectangular cavities and sound-absorbing holes to form a resonant sound-absorbing structure, effectively consuming the aerodynamic noise inside the fan, thereby reducing the noise during the operation of the mixed-flow fan while achieving dust removal.

Description

Technical Field

[0001] This invention relates to the field of mixed-flow fan technology, specifically a low-noise mixed-flow fan for large-volume ventilation. Background Technology

[0002] In modern industrial and commercial building air conditioning systems, mixed-flow fans are widely used in ventilation circulation systems because they combine the high-pressure characteristics of centrifugal fans with the large-flow advantages of axial fans. As people's requirements for indoor environmental quality increase, air conditioning systems not only need to meet the demand for large-volume air delivery, but also have stringent standards for noise control and air cleanliness during operation. Traditional mixed-flow fans still have some defects during operation.

[0003] Existing high-volume mixed-flow fans typically use a transmission method where the motor directly drives the impeller. This rigid connection structure is prone to mechanical vibration and aerodynamic noise at high speeds, making it difficult to meet the requirements of modern industry for a low-noise operating environment. To ensure ventilation quality, some fan inlets are equipped with dust filter structures. However, under high air volume conditions, dust easily accumulates on the filter surface, leading to increased air resistance and reduced efficiency. Moreover, existing filter cleaning methods mostly rely on manual shutdown maintenance, which is not only time-consuming and labor-intensive but also affects the continuity of the ventilation system. Although there are some automatic dust removal structures in existing technologies, they are often complex and prone to generating secondary dust during the dust removal process, which exacerbates the noise problem inside the fan.

[0004] Therefore, there is an urgent need for a low-noise mixed-flow fan for high-volume ventilation that can solve the above problems. By optimizing the transmission and dust removal structure, it can achieve low-noise operation and automatic filter cleaning while ensuring high air volume output. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a low-noise mixed-flow fan for high-volume ventilation, solving the problems of high noise, dust pollution, and difficulty in self-cleaning of traditional mixed-flow fans.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a low-noise mixed-flow fan for large-volume ventilation, comprising a housing, a motor fixedly installed inside the housing, and fan blades mounted on the output shaft of the motor via a coupling. The housing includes a fixed cylinder and an extension cylinder welded to one side of the fixed cylinder. A long shaft is installed at the center of the hub of the fan blades, and a magnetic transmission structure for speed reduction is installed on the outside of the long shaft. The magnetic transmission structure includes a deceleration magnetic ring, a gas distribution component for diverting flow is fixedly installed on the inner wall of one end of the fixed cylinder, a dust removal structure for dust removal is connected to one side of the gas distribution component, a dustproof structure for filtering dust is installed inside the extension cylinder, and a noise reduction plate for noise reduction is fixedly installed on the inner wall of the fixed cylinder. The dustproof structure includes a filter screen and an elastic element, and the dust removal structure includes a dust removal pipe and an extrusion head; The deceleration magnetic ring is used to drive the dust removal pipe to decelerate and rotate, so that the dust removal pipe can obtain a small part of the airflow from the mixed flow fan through the air distribution component. During the rotation, the elastic element is squeezed by the extrusion head to clean the filter screen. At the same time, it works in conjunction with the dust diversion and blowing inside the dust removal pipe to handle the dust removal operation after dust prevention.

[0007] Preferably, the motor is externally fitted with a shock-absorbing structure, which includes a spring shock absorber, a mounting plate, a mounting ring, and a rubber ring; Both ends of the spring shock absorber are fixedly connected to mounting blocks. The mounting ring is sleeved on the outside of the motor, and a rubber ring is filled between the mounting ring and the motor. The mounting plate is installed at equal intervals on the outer wall of the mounting ring, and one side of the mounting plate is fixedly connected to the inner wall of the fixed cylinder. Both ends of the spring shock absorber are fixedly connected to the outer wall of the motor and the mounting plate respectively through the mounting blocks, so that an elastic shock-absorbing installation is formed between the motor and the mounting plate.

[0008] Preferably, the magnetic transmission structure includes a first deceleration magnetic ring and a second deceleration magnetic ring; The deceleration magnetic ring is a deceleration magnetic ring one, and the deceleration magnetic ring one includes an inner ring, an inner magnetic block, a fixed ring, a steel column, a fixed connecting plate, an outer ring, and an outer magnetic block; The deceleration magnetic ring is a second deceleration magnetic ring, and the internal structure of the second deceleration magnetic ring is the same as that of the first deceleration magnetic ring. The inner ring is fixedly installed on the outer wall of the long shaft. Multiple inner magnetic blocks are interference-fitted inside the inner ring and arranged in a ring. The fixed ring is fixedly installed on one side of the motor through a fixed connecting plate. Multiple steel columns are interference-fitted inside the fixed ring in a ring. Multiple outer magnetic blocks are interference-fitted inside the outer ring in a ring.

[0009] Preferably, a fixed ring and an outer ring are sequentially fitted around the outer side of the inner ring, and a working gap is left between each pair of the inner ring, the fixed ring, and the outer ring; The magnetic poles of the multiple inner magnetic blocks and the multiple outer magnetic blocks are all adjacent and opposite magnetic poles, and the inner magnetic blocks and the corresponding outer magnetic blocks are opposite magnetic poles. The steel column is made of electrical pure iron or low carbon steel. The steel column modulates the magnetic field between the inner and outer magnetic blocks, and forms a speed difference through the difference in the number of outer and inner magnetic blocks, which is used to decelerate and transmit the rotational force of the long shaft.

[0010] Preferably, the air distribution assembly includes a fixed frame, a central column, an air distribution plate, a distribution shroud, a connecting frame, and an air inlet. Multiple fixing brackets are fixedly installed at equal angles on the inner wall of one end of the fixing cylinder. The central column is fixedly installed on the central axis of the fixing cylinder through the fixing brackets and extends into the interior of the flow divider. The air distribution plate is rotatably connected to the flow divider through a bearing. The air distribution plate is rotatably arranged outside the central column. The flow divider is fixedly connected to the fixing ring of the second deceleration magnetic ring. The connecting frame is fixedly connected to one side of the diffuser and to one end of the central column. Multiple air inlets are arranged in a ring on one side of the diffuser, and the exterior of the diffuser has a hemispherical structure with the air inlets facing the fan blades. An air storage chamber is formed between the air distribution plate and the diffuser.

[0011] Preferably, the dust removal structure further includes an air jet pipe and an installation strip. The cleaning pipe is symmetrically installed on both sides of the air distribution plate and is connected to the air storage chamber. The air jet pipe is fixedly connected to one end of the cleaning pipe and is connected to it. The air outlet of the air jet pipe is oriented towards the filter screen. The extrusion head is fixedly connected to one end of the cleaning pipe, the mounting strip is fixedly installed between the cleaning pipe and the outer ring, and the outer ring of the second deceleration magnetic ring is fixedly connected to the cleaning pipe through the mounting strip; The long shaft drives the inner ring to rotate, which in turn drives the outer ring to rotate the dust removal pipe and the air distribution plate. This is used to make the extrusion head squeeze the elastic element to vibrate and remove dust, and to cooperate with the jet pipe to blow air to remove dust.

[0012] Preferably, the dustproof structure further includes a movable ring, a sealing ring, a protrusion, a fixing strip, a fixing post, and a vibration spring; The movable ring is fixedly connected to the edge of the filter screen, and the filter screen has an outwardly convex arc surface structure. The fixed post passes through the movable ring and is movably disposed inside it. The vibration spring is sleeved on the outside of the fixed post and fixedly disposed between the movable ring and the fixed strip. The fixed strip is fixedly connected to the inner wall of one end of the fixed cylinder. One side of the sealing ring is fixedly connected to one side of the movable ring, and the other side is press-fitted to the shock-absorbing structure for a movable elastic seal between the movable ring and the fixed strip. The protrusion is fixedly connected to one side of the movable ring, and one side of the protrusion has an arc surface structure.

[0013] Preferably, the protrusion, fixing strip, fixing post, and vibration spring constitute the elastic element; The arc-shaped structure of the protrusion extends to one side of the fixing strip and is pressed against the extrusion head. The contact surface between the extrusion head and the protrusion is an arc-shaped structure. The extrusion head moves in a ring through a deceleration magnetic ring and squeezes the protrusion, causing it to push the filter screen to move. It then moves and resets momentarily through a vibration spring, creating low-frequency vibration to shake off the adsorbed dust.

[0014] Preferably, the bottom of the extension cylinder is provided with a dust outlet, and a dust collection structure is installed at the bottom of the dust outlet. The dust collection structure includes a dust collection box and a detachable dust box. The dust collection box is fixedly connected to the bottom of the dust outlet, and the detachable dust box is sealed and pulled out inside the dust collection box for cleaning the collected dust.

[0015] Preferably, the noise reduction plate includes an outer shell, a rectangular cavity, and sound-absorbing holes; Multiple rectangular cavities are formed inside the outer shell plate to create a consumption chamber, and multiple sound-absorbing holes are correspondingly formed on one side of the multiple rectangular cavities to eliminate some of the noise inside the fan through resonance.

[0016] Working Principle: This invention achieves low-noise, high-volume ventilation through a combination of magnetic drive and airflow self-cleaning mechanism. When the motor drives the long shaft and fan blades to rotate, the magnetic drive structure utilizes the attraction of opposite poles and the repulsion of like poles in the deceleration magnetic rings. The difference in the number of inner and outer magnetic blocks creates differential deceleration to transmit power. Simultaneously, the diversion component guides part of the airflow into the air storage chamber, driving the dust removal structure linked to the deceleration magnetic ring to rotate. This causes the extrusion head to periodically press against the elastic element of the dustproof structure, causing the filter screen to vibrate at low frequency and shake off dust. Combined with the diversion gas sprayed from the cleaning pipe, the dust filter component is automatically cleaned. Meanwhile, the noise reduction plate on the inner wall of the fan forms a resonant sound absorption structure through rectangular cavities and sound-absorbing holes. This, combined with the magnetic drive, eliminates mechanical vibration noise, ultimately achieving continuous low-noise operation and maintenance-free operation under high airflow conditions.

[0017] This invention provides a low-noise mixed-flow fan for high-volume ventilation. It offers the following advantages: 1. In dust removal and prevention, this invention replaces the traditional rigid coupling transmission with a magnetic transmission structure. Power transmission is achieved through magnetic coupling between the deceleration magnetic rings, eliminating frictional noise and vibration caused by mechanical contact. At the same time, noise reduction plates are set on the inner wall of the fan, and a resonant sound absorption structure is formed by rectangular cavities and sound-absorbing holes, which effectively consumes the aerodynamic noise inside the fan, thereby reducing the noise of the mixed flow fan during operation while achieving dust removal. 2. This invention utilizes the airflow of the fan itself, and through the air distribution component, a small portion of the airflow is diverted to the dust removal structure. Under the deceleration drive of the magnetic transmission structure, the dust removal pipe drives the extrusion head to rotate, periodically extruding the elastic element corresponding to the filter screen, causing the filter screen to vibrate at low frequency and shake off the dust. Combined with the dust diversion and blowing inside the dust removal pipe, the filter screen is automatically cleaned, avoiding manual shutdown for maintenance. This dust removal process utilizes airflow and vibration, avoiding the additional noise generated by mechanical scraping. 3. This invention, by setting a shock-absorbing structure on the outside of the motor and using the combination of spring shock absorbers and rubber rings, effectively isolates the transmission of motor vibration to the fan casing, improves the smoothness and low noise effect of the fan operation, and at the same time avoids the loosening of internal parts of the mixed flow fan caused by the vibration environment, thereby ensuring the long-term use of the mixed flow fan. 4. The magnetic transmission structure of the present invention uses steel columns to modulate the magnetic field and utilizes the difference in the number of inner and outer magnetic blocks to form a differential speed, which ensures the smoothness of power transmission. Furthermore, since there is a working gap inside the deceleration magnetic ring and it is a non-contact transmission, if the dust removal and dust prevention structure is damaged, the non-contact transmission method can serve as overload protection in case of pressure overload, avoiding excessive current damage to the motor, thereby increasing the service life of the mixed flow fan. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram showing the connection between the shock-absorbing structure and the dustproof structure of the present invention; Figure 4 This is a schematic diagram showing the position of the magnetic transmission structure of the present invention; Figure 5 This is a schematic diagram of the structure of the deceleration magnetic ring of the present invention; Figure 6 This is a schematic diagram of the vibration reduction structure of the present invention; Figure 7 This is a schematic diagram of the dust removal structure of the present invention; Figure 8 This is a schematic diagram of the internal structure of the dust collection structure of the present invention; Figure 9 This is a schematic diagram showing the disassembled dust removal structure and dust prevention structure of the present invention; Figure 10 This is a schematic diagram of the noise reduction board of the present invention; Figure 11 For the present invention Figure 6 Enlarged view of point A; Figure 12 For the present invention Figure 8 Enlarged view of point A; Figure 13 For the present invention Figure 10 Enlarged diagram of point A.

[0019] The components include: 1. Fixed cylinder; 2. Extension cylinder; 3. Motor; 4. Fan blade; 5. Vibration damping structure; 51. Spring vibration damper; 52. Mounting plate; 53. Mounting ring; 54. Rubber ring; 6. Magnetic transmission structure; 61. Deceleration magnetic ring one; 611. Inner ring; 612. Inner magnetic block; 613. Fixed ring; 614. Steel column; 615. Fixed connecting plate; 616. Outer ring; 617. Outer magnetic block; 62. Deceleration magnetic ring two; 7. Air distribution assembly; 71. Fixing frame; 72. Central column; 73. Air distribution plate. 74. Diverter hood; 75. Connecting frame; 76. Air inlet; 8. Dust removal structure; 81. Dust removal pipe; 82. Extrusion head; 83. Jet pipe; 84. Mounting strip; 9. Dustproof structure; 91. Movable ring; 92. Filter screen; 93. Sealing ring; 94. Protrusion; 95. Fixing strip; 96. Fixing column; 97. Vibration spring; 10. Dust collection structure; 101. Dust collection box; 102. Removable dust box; 11. Noise reduction plate; 1101. Outer shell plate; 1102. Rectangular cavity; 1103. Sound absorption hole. Detailed Implementation

[0020] 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.

[0021] Please see the appendix Figure 1-13 This invention provides a low-noise mixed-flow fan for large-volume ventilation, including a housing, a motor 3 fixedly installed inside the housing, and fan blades 4 mounted on the output shaft of the motor 3 via a coupling. The housing includes a fixed cylinder 1 and an extension cylinder 2 welded to one side of the fixed cylinder 1. A long shaft is installed at the center of the hub of the fan blades 4, and a magnetic transmission structure 6 for speed reduction transmission is installed on the outside of the long shaft. The magnetic transmission structure 6 includes a speed reduction magnetic ring. A gas distribution component 7 for flow splitting is fixedly installed on the inner wall of one end of the fixed cylinder 1. A dust removal structure 8 for dust removal is connected to one side of the gas distribution component 7. A dustproof structure 9 for dust filtration is installed inside the extension cylinder 2. A noise reduction plate 11 for noise reduction is fixedly installed on the inner wall of the fixed cylinder 1. The dustproof structure 9 includes a filter screen 92 and an elastic element. The dust removal structure 8 includes a dust removal pipe 81 and an extrusion head 82. The deceleration magnetic ring is used to drive the dust removal pipe 81 to rotate at a reduced speed, so that the dust removal pipe 81 can obtain a small part of the airflow from the mixed flow fan through the air distribution component 7. During the rotation, the elastic element is squeezed by the extrusion head 82 to clean the filter screen 92. At the same time, it works in conjunction with the dust diversion blowing inside the dust removal pipe 81 to handle the dust removal operation after dust prevention.

[0022] Please see the appendix Figure 1-5 and attached Figure 7 The deceleration magnetic ring is a first deceleration magnetic ring 61, which includes an inner ring 611, an inner magnetic block 612, a fixed ring 613, a steel column 614, a fixed connecting plate 615, an outer ring 616, and an outer magnetic block 617. The deceleration magnetic ring is a second deceleration magnetic ring 62, and the internal structure of the second deceleration magnetic ring 62 is the same as that of the first deceleration magnetic ring 61. The inner ring 611 is fixedly installed on the outer wall of the long shaft. Multiple inner magnetic blocks 612 are interference-fitted inside the inner ring 611 and arranged in a ring. The fixed ring 613 is fixedly installed on one side of the motor 3 through the fixed connecting plate 615. Multiple steel columns 614 are interference-fitted inside the fixed ring 613 in a ring. Multiple outer magnetic blocks 617 are interference-fitted inside the outer ring 616 in a ring.

[0023] A fixed ring 613 and an outer ring 616 are sequentially fitted around the inner ring 611, and a working gap is left between each pair of the inner ring 611, the fixed ring 613 and the outer ring 616. The magnetic poles of the multiple inner magnetic blocks 612 and the multiple outer magnetic blocks 617 are adjacent and opposite magnetic poles, and the inner magnetic block 612 and the corresponding outer magnetic block 617 are opposite magnetic poles. The steel column 614 is made of electrical pure iron or low carbon steel. The steel column 614 modulates the magnetic field between the inner magnetic block 612 and the outer magnetic block 617, and forms a differential speed through the difference in the number of outer magnetic blocks 617 and inner magnetic blocks 612, which is used to decelerate and transmit the rotational force of the long shaft. During operation, the motor 3 drives the long shaft and fan blades 4 to rotate, thereby drawing air in from the extension tube 2 and blowing it out from one end of the fixed tube 1. As the long shaft rotates, it drives the outer inner ring 611 to rotate, thereby modulating the magnetic field between the inner magnetic block 612 and the outer magnetic block 617 through the steel column 614. This causes the inner ring 611 to rotate while simultaneously driving the outer ring 616 to rotate at a reduced speed. The rotation of the outer ring 616 drives the connected air distribution assembly 7 to rotate. Furthermore, since the first and second reduction magnetic rings 61 and 62 are installed at both ends of the long shaft and are fixed to the cleaning pipe 81, the stability of the cleaning pipe 81 is increased.

[0024] Please see the appendix Figure 1-3 and attached Figure 7-9 Multiple fixed brackets 71 are fixedly installed at equal angles on the inner wall of one end of the fixed cylinder 1. The central column 72 is fixedly installed on the central axis of the fixed cylinder 1 through the fixed brackets 71 and extends into the interior of the flow divider 74. The air distribution plate 73 is rotatably connected to the flow divider 74 through the bearing. The air distribution plate 73 is rotatably set outside the central column 72. The flow divider 74 is fixedly connected to the fixed ring 613 of the deceleration magnetic ring 62. The connecting bracket 75 is fixedly connected to one side of the flow divider 74 and fixedly connected to one end of the central column 72. Multiple air inlets 76 are opened in a ring on one side of the flow divider 74. The exterior of the flow divider 74 has a hemispherical structure and the air inlets 76 are set towards the fan blade 4. An air storage chamber is formed between the air distribution plate 73 and the flow divider 74. When the fan blade 4 rotates and blows air, part of the airflow enters the interior of the distribution hood 74 through the air inlet 76. Since the cleaning pipe 81 is connected to the air storage chamber and the air pressure at the jet pipe 83 is lower than the air pressure inside the air storage chamber, the airflow enters the cleaning pipe 81 and flows out from the jet pipe 83 to blow dust off the filter screen 92. At the same time, since the cleaning pipe 81 is driven to rotate by the magnetic drive structure 6, the air distribution plate 73 rotates outside the distribution hood 74.

[0025] Please see the appendix Figure 7-9 and attached Figure 12 The dust removal structure 8 also includes a jet pipe 83 and an installation strip 84. The cleaning pipe 81 is symmetrically installed on both sides of the air distribution plate 73 and is connected to the air storage chamber. The jet pipe 83 is fixedly connected to one end of the cleaning pipe 81 and is connected to it. The air outlet of the jet pipe 83 is set towards the filter screen 92. The extrusion head 82 is fixedly connected to one end of the cleaning pipe 81. The installation strip 84 is fixedly installed between the cleaning pipe 81 and the outer ring 616. The outer ring 616 of the deceleration magnetic ring 62 is fixedly connected to the cleaning pipe 81 through the installation strip 84. The long shaft drives the inner ring 611 to rotate, so that the outer ring 616 drives the cleaning pipe 81 and the air distribution plate 73 to rotate. This is used to make the extrusion head 82 extrude the elastic element to vibrate and remove dust, and cooperate with the jet pipe 83 to blow air to remove dust. The movable ring 91 is fixedly connected to the edge of the filter screen 92, and the filter screen 92 has an outwardly protruding arc surface structure. The fixed post 96 passes through the movable ring 91 and is movably disposed inside it. The vibration spring 97 is sleeved on the outside of the fixed post 96 and fixedly disposed between the movable ring 91 and the fixed strip 95. The fixed strip 95 is fixedly connected to the inner wall of one end of the fixed cylinder 1. One side of the sealing ring 93 is fixedly connected to one side of the movable ring 91, and the other side is press-fitted with the shock absorption structure 5 for movable elastic sealing between the movable ring 91 and the fixed strip 95. The protrusion 94 is fixedly connected to one side of the movable ring 91, and one side of the protrusion 94 has an arc surface structure. The arc-shaped structure of the protrusion 94 extends to one side of the fixing strip 95 and is pressed against the extrusion head 82. The contact surface between the extrusion head 82 and the protrusion 94 is an arc-shaped structure. The extrusion head 82 moves in a ring through the deceleration magnetic ring and presses against the protrusion 94, causing it to push the filter screen 92 to move. The filter screen 92 is then reset by the vibration spring 97, generating a momentary movement and resetting, forming a low-frequency vibration to shake off the adsorbed dust. While the dust removal pipe 81 rotates, the extrusion head 82 presses against the protrusion 94, which in turn quickly presses the movable ring 91, causing it to slide outside the fixed column 96. At the same time, the sealing ring 93 stretches elastically, allowing the movable ring 91 to remain sealed between the movable ring 91 and the fixed strip 95 after movement, preventing dust from entering. After the movable ring 91 moves, it is immediately reset by the elasticity of the vibration spring 97, while the sealing ring 93 is pressed to maintain the seal. This allows the dust on the outside of the filter screen 92 to be shaken off by the extrusion head 82 while blowing dust, preventing dust or debris from clogging the filter screen 92 after long-term use. This ensures that the mixed flow fan can perform dust self-cleaning and guarantees its long-term stable use.

[0026] Please see the appendix Figure 1 , 2 and attached Figure 8 The bottom of the extension tube 2 is provided with a dust outlet, and a dust collection structure 10 is installed at the bottom of the dust outlet. The dust collection structure 10 includes a dust collection box 101 and a detachable dust box 102. The dust collection box 101 is fixedly connected to the bottom of the dust outlet, and the detachable dust box 102 is sealed and pulled out inside the dust collection box 101 for cleaning the collected dust.

[0027] After being shaken off, the dust falls downwards into the dust collection box 101 at the dust inlet. The dust or impurity particles are collected by the removable dust box 102, preventing the dust from being re-adsorbed onto the filter screen 92 after being shaken off or blown away. When the mixed flow fan is regularly inspected, the dust collection box 101 can be pulled outwards, making it easy to remove the dust collection box 101 from the inside of the removable dust box 102 for processing of the collected dust or impurities. The openings for installation and removal of the removable dust box 102 and the dust collection box 101 are equipped with sealing strips, ensuring a tight seal between the two when the removable dust box 102 is placed inside the dust collection box 101, preventing airflow from entering through gaps and causing dust to rise.

[0028] Please see the appendix Figure 1-4 6, 10, 11 and appendix Figure 13 Both ends of the spring shock absorber 51 are fixedly connected to mounting blocks. The mounting ring 53 is sleeved on the outside of the motor 3, and the rubber ring 54 is filled between the mounting ring 53 and the motor 3. The mounting plate 52 is installed at equal intervals on the outer wall of the mounting ring 53, and one side of the mounting plate 52 is fixedly connected to the inner wall of the fixed cylinder 1. Both ends of the spring shock absorber 51 are fixedly connected to the outer wall of the motor 3 and the mounting plate 52 respectively through the mounting blocks, so that the motor 3 and the mounting plate 52 form an elastic shock-absorbing installation. Multiple rectangular cavities 1102 are opened inside the outer shell plate 1101 to form a consumption chamber. Multiple sound-absorbing holes 1103 are correspondingly opened on one side of the multiple rectangular cavities 1102 to eliminate some of the noise inside the fan through resonance. When the motor 3 is in use, it usually resonates with the mounting bracket or plate, which leads to noise. Because the mounting ring 54 is filled with an elastic material such as a rubber ring 54 between the mounting ring 53 and the motor 3, the vibration of the motor 3 during use can increase the buffer between the motor 3 and the mounting ring 53, thus avoiding noise. At the same time, when vibration occurs, the piston inside the spring damper 51 squeezes the gas in its cylinder and the piston is reset by the spring, thereby reducing vibration. When the fan is in use, due to the high pressure and large air volume airflow inside, a certain amount of noise will be generated when the airflow passes through the internal structure. At this time, when the vibrating airflow enters the rectangular cavity 1102 through the sound absorption hole 1103, the noise with a similar vibration frequency is resonated and consumed due to the Helmholtz resonance principle, thereby reducing the noise. In addition, through the above-mentioned dust prevention and dust removal operations, the resonance noise caused by dust entering the fan is prevented, thus reducing the noise generation to a certain extent and improving the low noise performance and operational reliability of the mixed flow fan.

[0029] 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 low-noise mixed-flow fan for high-volume ventilation, comprising a housing, a motor (3) fixedly installed inside the housing, and fan blades (4) mounted on the output shaft of the motor (3) via a coupling, characterized in that: The outer casing includes a fixed cylinder (1) and an extension cylinder (2) welded to one side of the fixed cylinder (1). A long shaft is installed at the center of the hub of the fan blade (4), and a magnetic transmission structure (6) for speed reduction transmission is installed on the outside of the long shaft. The magnetic transmission structure (6) includes a deceleration magnetic ring. A gas distribution component (7) for diverting flow is fixedly installed on the inner wall of one end of the fixed cylinder (1). A dust removal structure (8) for dust removal is connected to one side of the gas distribution component (7). A dustproof structure (9) for filtering dust is installed inside the extension cylinder (2). A noise reduction plate (11) for noise reduction is fixedly installed on the inner wall of the fixed cylinder (1). The dustproof structure (9) includes a filter screen (92) and an elastic element, and the dust removal structure (8) includes a dust removal pipe (81) and an extrusion head (82). The deceleration magnetic ring is used to drive the dust removal pipe (81) to decelerate and rotate, so that the dust removal pipe (81) can obtain a small part of the airflow from the mixed flow fan through the air distribution component (7), and squeeze the elastic element through the extrusion head (82) during the rotation to clean the filter screen (92). At the same time, it cooperates with the dust removal pipe (81) to split the dust and handle the dust removal operation after dust prevention.

2. A low-noise mixed-flow fan for large-volume ventilation according to claim 1, characterized in that, The motor (3) is fitted with a shock-absorbing structure (5), which includes a spring shock absorber (51), a mounting plate (52), a mounting ring (53), and a rubber ring (54). Both ends of the spring shock absorber (51) are fixedly connected to mounting blocks. The mounting ring (53) is sleeved on the outside of the motor (3), and the rubber ring (54) is filled between the mounting ring (53) and the motor (3). The mounting plate (52) is installed at equal distances on the outer wall of the mounting ring (53), and one side of the mounting plate (52) is fixedly connected to the inner wall of the fixed cylinder (1). Both ends of the spring shock absorber (51) are fixedly connected to the outer wall of the motor (3) and the mounting plate (52) respectively through the mounting blocks, so that the motor (3) and the mounting plate (52) form an elastic shock-absorbing installation.

3. A low-noise mixed-flow fan for large-volume ventilation according to claim 1, characterized in that, The magnetic transmission structure (6) includes a first deceleration magnetic ring (61) and a second deceleration magnetic ring (62). The deceleration magnetic ring is a deceleration magnetic ring one (61), and the deceleration magnetic ring one (61) includes an inner ring (611), an inner magnetic block (612), a fixed ring (613), a steel column (614), a fixed connecting plate (615), an outer ring (616), and an outer magnetic block (617). The deceleration magnetic ring is a second deceleration magnetic ring (62), and the internal structure of the second deceleration magnetic ring (62) is the same as the internal structure of the first deceleration magnetic ring (61); The inner ring (611) is fixedly installed on the outer wall of the long shaft. Multiple inner magnetic blocks (612) are interference-fitted inside the inner ring (611) and arranged in a ring. The fixed ring (613) is fixedly installed on one side of the motor (3) through a fixed connecting plate (615). Multiple steel columns (614) are interference-fitted inside the fixed ring (613) in a ring. Multiple outer magnetic blocks (617) are interference-fitted inside the outer ring (616) in a ring.

4. A low-noise mixed-flow fan for large-volume ventilation according to claim 3, characterized in that, A fixed ring (613) and an outer ring (616) are sequentially fitted around the inner ring (611), and a working gap is left between each pair of the inner ring (611), the fixed ring (613) and the outer ring (616); The magnetic poles of the multiple inner magnetic blocks (612) and the multiple outer magnetic blocks (617) are all adjacent and opposite magnetic poles, and the inner magnetic block (612) and the corresponding outer magnetic block (617) are opposite magnetic poles. The steel column (614) is made of electrical pure iron or low carbon steel. The steel column (614) modulates the magnetic field between the inner magnetic block (612) and the outer magnetic block (617), and forms a differential speed through the difference in the number of the outer magnetic block (617) and the inner magnetic block (612), which is used to decelerate and transmit the rotational force of the long shaft.

5. A low-noise mixed-flow fan for high-volume ventilation according to claim 3, characterized in that, The air distribution assembly (7) includes a fixed frame (71), a central column (72), an air distribution plate (73), a flow divider (74), a connecting frame (75), and an air inlet (76). Multiple fixing brackets (71) are fixedly installed at equal angles on the inner wall of one end of the fixing cylinder (1). The central column (72) is fixedly installed on the central axis of the fixing cylinder (1) through the fixing brackets (71) and extends into the interior of the flow divider (74). The air distribution plate (73) is rotatably connected to the flow divider (74) through a bearing. The air distribution plate (73) is rotatably arranged outside the central column (72). The flow divider (74) is fixedly connected to the fixing ring (613) of the deceleration magnetic ring II (62). The connecting frame (75) is fixedly connected to one side of the diffuser (74) and fixedly connected to one end of the central column (72). Multiple air inlets (76) are arranged in a ring on one side of the diffuser (74), and the exterior of the diffuser (74) has a hemispherical structure, with the air inlets (76) facing the fan blades (4). An air storage chamber is formed between the air distribution plate (73) and the diffuser (74).

6. A low-noise mixed-flow fan for large-volume ventilation according to claim 5, characterized in that, The dust removal structure (8) also includes a jet pipe (83) and an installation strip (84). The cleaning pipe (81) is symmetrically installed on both sides of the air distribution plate (73), and the cleaning pipe (81) is connected to the air storage chamber. The jet pipe (83) is fixedly connected to one end of the cleaning pipe (81) and is connected to it. The air outlet of the jet pipe (83) is set towards the filter screen (92). The extrusion head (82) is fixedly connected to one end of the cleaning pipe (81), the mounting strip (84) is fixedly installed between the cleaning pipe (81) and the outer ring (616), and the outer ring (616) of the deceleration magnetic ring II (62) is fixedly connected to the cleaning pipe (81) through the mounting strip (84); The long shaft drives the inner ring (611) to rotate, causing the outer ring (616) to drive the dust removal pipe (81) and the air distribution plate (73) to rotate, so that the extrusion head (82) can extrude the elastic element to vibrate and remove dust, and cooperate with the jet pipe (83) to blow air to remove dust.

7. A low-noise mixed-flow fan for large-volume ventilation according to claim 1, characterized in that, The dustproof structure (9) also includes a movable ring (91), a sealing ring (93), a protrusion (94), a fixing strip (95), a fixing post (96), and a vibration spring (97). The movable ring (91) is fixedly connected to the edge of the filter screen (92), and the filter screen (92) is an outwardly protruding arc surface structure. The fixed post (96) passes through the movable ring (91) and is movably disposed inside it. The vibration spring (97) is sleeved on the outside of the fixed post (96) and fixedly disposed between the movable ring (91) and the fixed strip (95). The fixed strip (95) is fixedly connected to the inner wall of one end of the fixed cylinder (1). One side of the sealing ring (93) is fixedly connected to one side of the movable ring (91), and the other side is press-fitted to the shock-absorbing structure (5) for movable elastic sealing between the movable ring (91) and the fixed strip (95). The protrusion (94) is fixedly connected to one side of the movable ring (91), and one side of the protrusion (94) is an arc surface structure.

8. A low-noise mixed-flow fan for large-volume ventilation according to claim 7, characterized in that, The protrusion (94), fixing strip (95), fixing post (96), and vibration spring (97) constitute the elastic element; The arc-shaped structure of the protrusion (94) extends to one side of the fixing strip (95) and is pressed against the extrusion head (82). The contact surface between the extrusion head (82) and the protrusion (94) is an arc-shaped structure. The extrusion head (82) moves in a ring through a deceleration magnetic ring and extrudes through the protrusion (94), causing it to push the filter screen (92) to move. It is then reset by a vibration spring (97) to generate instantaneous movement and reset, forming a low-frequency vibration to shake off the adsorbed dust.

9. A low-noise mixed-flow fan for large-volume ventilation according to claim 1, characterized in that, The bottom of the extension tube (2) is provided with a dust outlet, and a dust collection structure (10) is installed at the bottom of the dust outlet. The dust collection structure (10) includes a dust collection box (101) and a detachable dust box (102). The dust collection box (101) is fixedly connected to the bottom of the dust outlet, and the detachable dust box (102) is sealed and pulled out inside the dust collection box (101) for cleaning the collected dust.

10. A low-noise mixed-flow fan for high-volume ventilation according to claim 1, characterized in that, The noise reduction plate (11) includes an outer shell plate (1101), a rectangular cavity (1102), and sound absorption holes (1103). Multiple rectangular cavities (1102) are formed inside the outer shell plate (1101) to form a consumption chamber, and multiple sound-absorbing holes (1103) are correspondingly formed on one side of the multiple rectangular cavities (1102) to eliminate some of the noise inside the fan through resonance.

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