Single-inlet centrifugal fan

Abstract

This invention discloses a single-inlet centrifugal fan, belonging to the technical field of centrifugal fans. The invention includes a fan housing, with a drive motor fixedly mounted on the outer side of the housing. The fan housing has an air inlet and an air outlet. A rear cover plate is fixedly mounted on the output end of the drive motor, and a front cover plate is parallel to the outer side of the rear cover plate. Blades are elastically and evenly mounted between the rear and front cover plates. An adjusting motor is fixedly mounted on the outer side of the fan housing, and a transmission assembly for driving the blades to rotate synchronously is provided between the adjusting motor and the blades. A filter screen is elastically and telescopically connected to the inner side of the air inlet. This single-inlet centrifugal fan allows for convenient adjustment of the blade angle, thereby controlling the intake suction intensity, impeller work, and internal air pressure distribution. It offers a wide adjustment range and improves the automatic cleaning effect of the filter screen.

Description

Technical Field

[0001] This invention relates to the field of centrifugal fan technology, specifically a single-inlet centrifugal fan. Background Technology

[0002] A single-inlet centrifugal fan is a fluid machine that uses centrifugal force to transport gas. It adopts a single-side air inlet design, where gas enters the centrifugal chamber through a single air inlet, is accelerated by the impeller, and is discharged radially to form a high-pressure airflow. It is widely used in many fields such as industrial production, building ventilation, and environmental protection.

[0003] Prior art (Chinese patent publication number: CN108035914A, publication date: 2018-05-15) discloses a single-inlet explosion-proof centrifugal fan, including a base, a mounting seat at the upper end of the base, a centrifugal fan at the upper end of the mounting seat, a protective net on the centrifugal fan, a duct at the upper end of the centrifugal fan, a movable rod inside the duct, and symmetrically arranged support rods on the duct, with the support rods fixedly connected to the duct. Grooves are formed on both sides of the movable rod, and the support rods are located within the grooves. Fixing blocks are symmetrically arranged within the grooves, distributed on both sides of the support rods. Each fixing block has a support leg at the end furthest from the groove. This fan has a debris interception net, which is easy to disassemble, saving workers a significant amount of time and effort. Chinese Patent CN117006107A (published on 2023-11-07) discloses a centrifugal fan with a purification system, which includes a shock-absorbing base and a centrifugal fan housing mounted on top of it. The housing has an air inlet, a spiral duct one, a spiral duct two, an air outlet duct, and an air outlet connected sequentially from its side wall to its top. The bottom of the spiral duct two is located below the bottom of the spiral duct one. A filter screen is fixed at the air inlet. Mounting frames are provided on both sides of the filter screen and mounted on the housing. A cleaning brush is installed between the two mounting frames to abut against the filter screen. The bottom of the spiral duct two has a storage channel extending to the side wall of the housing. This solves the problem that the air intake of the centrifugal fan decreases with the increase of usage time, and to a certain extent purifies the air passing through the centrifugal fan, improving air quality.

[0004] Existing single-inlet centrifugal fans can only adjust the power of the drive motor when adjusting the airflow, which means that the speed can only be adjusted as a whole. The air pressure drops sharply with the square of the speed, and it is impossible to ensure both air pressure and air volume at the same time. The adjustment is limited and the adaptability is poor. Moreover, it is very easy to enter the surge zone at low speed and low load, resulting in airflow backflow, increased vibration and noise, and poor operating stability. Summary of the Invention

[0005] The purpose of this invention is to provide a single-inlet centrifugal fan to solve the problems mentioned in the background art. Currently, most single-inlet centrifugal fans on the market can only adjust the power of the drive motor when adjusting the airflow, which means that the speed can only be adjusted as a whole. The air pressure drops sharply with the square of the speed, and it is impossible to ensure both air pressure and air volume at the same time. The adjustment is limited, the adaptability is poor, and it is very easy to enter the surge zone at low speed and low load, resulting in airflow backflow, increased vibration and noise, and poor operating stability.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a single-inlet centrifugal fan, comprising a fan housing, a drive motor fixedly installed on the outer side of the fan housing, and an air inlet and an air outlet provided on the fan housing, a rear cover plate fixedly installed at the output end of the drive motor, and a front cover plate arranged parallel to the outer side of the rear cover plate, blades being elastically and evenly installed between the rear cover plate and the front cover plate, an adjusting motor fixedly installed on the outer side of the fan housing, and a transmission component for driving the blades to rotate synchronously and adjust is provided between the adjusting motor and the blades, and a filter screen is elastically and telescopically connected to the inner side of the air inlet.

[0007] Preferably, the transmission assembly includes a threaded rod fixedly installed at the output end of the regulating motor, and an adjusting plate is threadedly connected to the outer side of the threaded rod. A guide rod parallel to the threaded rod is fixedly installed on the inner wall of the fan housing, and the guide rod slides through the adjusting plate.

[0008] Preferably, a rotating ring is rotatably mounted on the outer side of the adjusting plate, and a toothed ring is rotatably mounted on the outer side of the front cover plate. An adjusting component is connected between the rotating ring and the toothed ring. During the horizontal movement of the rotating ring driven by the adjusting plate, the adjusting component drives the toothed ring to rotate. A transmission gear is fixedly mounted on the shaft of the blade, and the toothed ring and the transmission gear are meshed together. During the rotation of the toothed ring, the blade is driven to rotate synchronously for adjustment.

[0009] Preferably, the rotating ring is provided with connecting rods evenly, and the connecting rods slide through the front cover plate, and the rotating ring rotates synchronously through the connecting rods during the rotation of the front cover plate.

[0010] Preferably, the adjustment assembly includes a fixed post fixedly installed on the outside of the rotating ring, and a ball is embedded in the top of the fixed post. A guide block is fixedly installed on the outside of the toothed ring, and the side of the guide block near the ball is set as an inclined surface. As the rotating ring approaches the front cover plate, the ball rolls along the inclined surface of the guide block to drive the toothed ring to rotate and adjust.

[0011] The above method can drive multiple blades to rotate synchronously, thereby adjusting the ventilation effect without changing the power of the drive motor.

[0012] Preferably, a fixed air inlet pipe is uniformly fixedly provided on the outer side of the filter screen, and the fixed air inlet pipe slides through the frame installed inside the air inlet, and a spring is fixedly connected between the frame inside the air inlet and the filter screen.

[0013] Preferably, a rotating seat is elastically mounted on the inner side of the air inlet via a torsion spring, and a cylindrical sealing elastic component is fixedly connected between the filter and the rotating seat. When the filter slides toward the rotating seat, the rotating seat rotates elastically, and the sealing elastic component is twisted when the rotating seat rotates elastically.

[0014] Preferably, the rotating seat has an internal cavity, and the space between the cavity on the inner side of the rotating seat and the air inlet and the sealing elastic rubber part is connected. The rotating seat is uniformly connected with backflush pipes that open towards the filter screen. The cavity on the inner side of the rotating seat is connected to the backflush pipes, and one-way valves are provided on both the fixed air inlet pipe and the backflush pipe. During the twisting of the sealing elastic rubber part, air is drawn in through the fixed air inlet pipe into the space between the air inlet and the sealing elastic rubber part. When the sealing elastic rubber part returns to its original state, the drawn-in air is blown towards the filter screen through the backflush pipe.

[0015] Preferably, a fixed frame is fixedly installed on the inner side of the rotating seat, and a rotating shaft is slidably arranged on the fixed frame. The rotating shaft is rotatably installed on the filter screen, and a scraper is fixedly installed on the rotating shaft. The scraper is in contact with the filter surface of the filter screen. A switch is fixedly installed on the inner side of the air inlet, and the switch is squeezed during the movement of the fixed air inlet pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are: the single-inlet centrifugal fan can conveniently adjust the blade angle, thereby controlling the intake suction intensity, impeller work, and internal air pressure distribution, with a wide adjustment range, and can promote the automatic cleaning effect of the filter screen, as detailed below; 1. Equipped with an adjusting plate, a rotating ring, a gear ring, and a transmission gear, the adjusting plate is driven by the adjusting motor to move inside the fan housing. This causes the adjusting plate to move synchronously with the rotating ring, which in turn causes the fixed column on the outer side of the rotating ring to drive the ball bearings to roll along the guide block. This, in turn, drives the gear ring to rotate and adjust. The gear ring, through meshing with the transmission gear, drives multiple blades to rotate and adjust synchronously. This allows for adjustment of the ventilation effect without changing the power of the drive motor, and provides a wide adjustment range.

[0017] 2. Equipped with a filter screen and a fixed air inlet pipe, when a large amount of impurities are filtered out on the outside of the filter screen and partially block the filter holes, the filter screen slides along the air inlet under the action of air pressure. When the fixed air inlet pipe moves and the switch is pressed, the switch can control the adjustment motor to drive the blades to rotate and adjust, so that the air force on the inside of the air inlet is rapidly reduced. At this time, the filter screen is instantly reset under the action of spring force, and then the filtered material on the outside of the filter screen is automatically shaken off.

[0018] 3. Equipped with a rotating seat, a sealing elastic component, and a backflush pipe, the rotating seat rotates elastically under the force of a torsion spring as the filter moves. This twists the sealing elastic component, allowing air to be drawn into the space between the air inlet and the sealing elastic component through the fixed air inlet pipe. When the sealing elastic component returns to its original position, air is blown onto the filter through the backflush pipe, thus achieving backflushing of impurities on the filter. The rotation of the rotating seat also drives the scraper to scrape away impurities on the outside of the filter, ensuring effective filtration and air intake. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a schematic diagram of the blade mounting structure of the present invention; Figure 3 This is a schematic diagram of the connection structure between the adjusting plate and the rotating ring of the present invention; Figure 4 This is a schematic diagram of the mounting structure of the front cover plate and the toothed ring of the present invention; Figure 5 For the present invention Figure 4 Enlarged structural diagram at point A in the middle; Figure 6 This is a schematic diagram of the installation structure of the sealing elastic rubber component of the present invention; Figure 7 This is a schematic cross-sectional view of the air inlet structure of the present invention; Figure 8 For the present invention Figure 7 Enlarged structural diagram at point B.

[0020] In the diagram: 1. Fan housing; 2. Drive motor; 3. Air inlet; 4. Air outlet; 5. Rear cover; 6. Front cover; 7. Blades; 8. Adjusting motor; 9. Threaded rod; 10. Guide rod; 11. Adjusting plate; 12. Rotating ring; 13. Connecting rod; 14. Fixed column; 15. Ball bearing; 16. Gear ring; 17. Guide block; 18. Transmission gear; 19. Filter screen; 20. Fixed air inlet pipe; 21. Rotating seat; 22. Sealing elastic rubber part; 23. Backflush pipe; 24. Fixing frame; 25. Rotating shaft; 26. Scraper; 27. Switch. Detailed Implementation

[0021] 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.

[0022] Example 1: Existing single-inlet centrifugal fans mostly only allow adjustment of the motor power when regulating airflow, resulting in only overall speed adjustment. The air pressure drops sharply with the square of the speed, making it impossible to simultaneously guarantee air pressure and airflow. This limits adjustment and reduces adaptability. To solve this technical problem, this example discloses the following technical content. Please refer to [link / reference]. Figures 1-5 As shown; A single-inlet centrifugal fan includes a fan housing 1, a drive motor 2 fixedly mounted on the outside of the fan housing 1, and an air inlet 3 and an air outlet 4 provided on the fan housing 1. A rear cover plate 5 is fixedly mounted on the output end of the drive motor 2, and a front cover plate 6 is arranged parallel to the outside of the rear cover plate 5. Blades 7 are elastically and evenly mounted between the rear cover plate 5 and the front cover plate 6. An adjustment motor 8 is fixedly mounted on the outside of the fan housing 1, and a transmission component for driving the blades 7 to rotate synchronously is provided between the adjustment motor 8 and the blades 7.

[0023] The transmission assembly includes a threaded rod 9 fixedly mounted on the output end of the regulating motor 8, with an adjusting plate 11 threadedly connected to the outer side of the threaded rod 9. A guide rod 10 parallel to the threaded rod 9 is fixedly mounted on the inner wall of the fan housing 1, and the guide rod 10 slides through the adjusting plate 11. A rotating ring 12 is rotatably mounted on the outer side of the adjusting plate 11, and a gear ring 16 is rotatably mounted on the outer side of the front cover plate 6. An adjusting assembly connects the rotating ring 12 and the gear ring 16. During the horizontal movement of the rotating ring 12 driven by the adjusting plate 11, the adjusting assembly drives the gear ring 16 to rotate. A transmission gear 18 is fixedly mounted on the shaft of the blade 7, and the gear ring 16 and the transmission gear 18... The gear ring 16 is engaged and connected, and the blade 7 is driven to rotate synchronously during the rotation of the gear ring 16. The rotating ring 12 is evenly provided with connecting rods 13, and the connecting rods 13 slide through the front cover plate 6. During the rotation of the front cover plate 6, the rotating ring 12 is driven to rotate synchronously through the connecting rods 13. The adjustment component includes a fixed post 14 fixedly installed on the outside of the rotating ring 12, and a ball bearing 15 is embedded in the top of the fixed post 14. A guide block 17 is fixedly installed on the outside of the gear ring 16, and the side of the guide block 17 near the ball bearing 15 is set as an inclined surface. During the rotation of the rotating ring 12, the ball bearing 15 rolls along the inclined surface of the guide block 17 to push the gear ring 16 to rotate and adjust.

[0024] By starting the drive motor 2, the rear cover plate 5, the front cover plate 6, and the blades 7 can be rotated, causing the fan housing 1 to draw in air through the air inlet 3 and discharge it through the air outlet 4. By controlling the adjustment motor 8 to drive the threaded rod 9 to rotate, the threaded rod 9 can drive the adjustment plate 11 to slide along the guide rod 10 through the threaded connection. This allows the adjustment plate 11 to drive the rotating ring 12 to move synchronously, causing the fixed column 14 on the outside of the rotating ring 12 to drive the ball bearing 15 to roll along the guide block 17, thereby driving the gear ring 16 to rotate and adjust. The gear ring 16, through meshing with the transmission gear 18, drives multiple blades 7 to rotate and adjust synchronously. Thus, the ventilation effect can be adjusted without changing the power of the drive motor 2, and the adjustment range is wide.

[0025] Example 2: The technical content disclosed in this example is a further improvement based on Example 1. Existing single-inlet centrifugal fans are inconvenient for automatically cleaning the filter mechanism without shutting down. To further solve this technical problem, this example discloses the following technical content: Figure 1 and Figures 6-8 As shown; a filter 19 is elastically telescopically connected to the inner side of the air inlet 3, and a fixed air inlet pipe 20 is uniformly fixedly arranged on the outer side of the filter 19. The fixed air inlet pipe 20 slides through the frame installed inside the air inlet 3, and a spring is fixedly connected between the frame inside the air inlet 3 and the filter 19.

[0026] A rotating seat 21 is elastically mounted on the inner side of the air inlet 3 via a torsion spring. A cylindrical sealing elastic component 22 is fixedly connected between the filter 19 and the rotating seat 21. When the filter 19 slides toward the rotating seat 21, the rotating seat 21 elastically rotates. Simultaneously, the rotating seat 21 twists the sealing elastic component 22 during its elastic rotation. A cavity is provided inside the rotating seat 21, and the cavity inside the rotating seat 21 communicates with the space between the air inlet 3 and the sealing elastic component 22. Backflush pipes 23 with openings facing the filter 19 are evenly connected to the rotating seat 21. The cavity inside the rotating seat 21 communicates with the backflush pipes 23, and the air inlet pipe 20 and the backflush pipe 23 are fixed. Both are equipped with one-way valves. During the twisting of the sealing elastic rubber part 22, air is drawn in through the fixed air intake pipe 20 into the space between the air inlet 3 and the sealing elastic rubber part 22. When the sealing elastic rubber part 22 returns to its original state, the drawn-in air is blown towards the filter screen 19 through the back-blowing pipe 23. A fixed bracket 24 is fixedly installed on the inner side of the rotating seat 21, and a rotating shaft 25 is slidably installed on the fixed bracket 24. The rotating shaft 25 is rotatably installed on the filter screen 19, and a scraper 26 is fixedly installed on the rotating shaft 25. At the same time, the scraper 26 is attached to the filter surface of the filter screen 19. A switch 27 is fixedly installed on the inner side of the air inlet 3, and the switch 27 is squeezed during the movement of the fixed air intake pipe 20.

[0027] When the equipment has been working for a long time, and the outer side of the filter screen 19 becomes clogged with impurities, the filter screen 19 slides along the air inlet 3 under air pressure. When the fixed air inlet pipe 20 moves and presses the switch 27, the switch 27 controls the adjusting motor 8 to drive the blade 7 to rotate and adjust, reducing the tilt angle of the blade 7, which causes the airflow inside the air inlet 3 to decrease rapidly. At this time, the filter screen 19 instantly resets under the action of the spring force, thus automatically shaking off the filtered material on the outer side of the filter screen 19. As the filter screen 19 moves, the rotating seat 21 rotates elastically under the action of the torsion spring force, thereby twisting the sealing elastic rubber part 22, and the air intake... The increased space between the air inlet 3 and the sealing elastic rubber part 22 allows air to be drawn in through the fixed air inlet pipe 20. A filter structure can be installed on the fixed air inlet pipe 20 to ensure the cleanliness of the drawn-in air. When the filter screen 19 is reset, the sealing elastic rubber part 22 is also restored. At this time, the drawn-in air is blown towards the filter screen 19 through the backflush pipe 23, thereby achieving backflushing of impurities on the filter screen 19. The rotation of the rotating seat 21 can improve the backflushing effect of the backflush pipe 23, and at the same time drive the scraper 26 to scrape off impurities on the outside of the filter screen 19, ensuring the filtration and air intake effects.

[0028] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A single-inlet centrifugal ventilator, comprising a ventilator shell (1), a driving motor (2) fixedly installed on the outer side of the ventilator shell (1), an air inlet (3) and an air outlet (4) arranged on the ventilator shell (1), a rear cover plate (5) fixedly installed on the output end of the driving motor (2), and a front cover plate (6) arranged in parallel on the outer side of the rear cover plate (5), characterized in that, Blades (7) are installed elastically and evenly between the rear cover plate (5) and the front cover plate (6). An adjustment motor (8) is fixedly installed on the outside of the fan housing (1). A transmission component for driving the blades (7) to rotate synchronously is provided between the adjustment motor (8) and the blades (7). A filter screen (19) is elastically and telescopically connected to the inside of the air inlet (3).

2. A single inlet centrifugal fan as claimed in claim 1, characterized in that: The transmission assembly includes a threaded rod (9) fixedly installed at the output end of the regulating motor (8), and an adjusting plate (11) is threadedly connected to the outer side of the threaded rod (9). A guide rod (10) parallel to the threaded rod (9) is fixedly installed on the inner wall of the fan housing (1), and the guide rod (10) slides through the adjusting plate (11).

3. A single inlet centrifugal fan as claimed in claim 2, characterized in that: A rotating ring (12) is rotatably mounted on the outer side of the adjusting plate (11), and a toothed ring (16) is rotatably mounted on the outer side of the front cover plate (6). An adjusting component is connected between the rotating ring (12) and the toothed ring (16). The rotating ring (12) drives the toothed ring (16) to rotate through the adjusting component during the horizontal movement driven by the adjusting plate (11). A transmission gear (18) is fixedly mounted on the shaft of the blade (7). The toothed ring (16) and the transmission gear (18) are meshed and connected. During the rotation of the toothed ring (16), the blade (7) is driven to rotate synchronously.

4. A single inlet centrifugal fan as claimed in claim 3, characterised in that: The rotating ring (12) is evenly provided with connecting rods (13), and the connecting rods (13) slide through the front cover plate (6). During the rotation of the front cover plate (6), the rotating ring (12) is driven to rotate synchronously through the connecting rods (13).

5. A single inlet centrifugal fan as claimed in claim 3, characterized in that: The adjustment assembly includes a fixed post (14) fixedly installed on the outside of the rotating ring (12), and a ball (15) is embedded in the top of the fixed post (14). A guide block (17) is fixedly installed on the outside of the toothed ring (16), and the side of the guide block (17) near the ball (15) is set as an inclined surface. During the process of the rotating ring (12) approaching the front cover plate (6), the ball (15) rolls along the inclined surface of the guide block (17) to push the toothed ring (16) to rotate and adjust.

6. A single inlet centrifugal fan as claimed in claim 1, characterized in that: A fixed air inlet pipe (20) is uniformly fixed on the outer side of the filter (19), and the fixed air inlet pipe (20) slides through the frame installed inside the air inlet (3), and a spring is fixedly connected between the frame inside the air inlet (3) and the filter (19).

7. A single inlet centrifugal fan as claimed in claim 1, characterized in that: The air inlet (3) has a rotating seat (21) installed on its inner side by a torsion spring, and a cylindrical sealing elastic rubber part (22) is fixedly connected between the filter (19) and the rotating seat (21). When the filter (19) slides toward the rotating seat (21), the rotating seat (21) rotates elastically, and the rotating seat (21) twists the sealing elastic rubber part (22) when it rotates elastically.

8. A single inlet centrifugal fan as claimed in claim 7, characterised in that: The rotating seat (21) has an internal cavity, and the space between the cavity on the inner side of the rotating seat (21) and the air inlet (3) and the sealing elastic rubber part (22) is connected. The rotating seat (21) is evenly connected with backflush pipes (23) with openings facing the filter screen (19). The cavity on the inner side of the rotating seat (21) and the backflush pipes (23) are connected. One-way valves are provided on both the fixed air inlet pipe (20) and the backflush pipes (23). During the twisting process of the sealing elastic rubber part (22), air is drawn in through the fixed air inlet pipe (20) and the space between the air inlet (3) and the sealing elastic rubber part (22). When the sealing elastic rubber part (22) returns to its original state, the drawn-in air is blown towards the filter screen (19) through the backflush pipes (23).

9. A single inlet centrifugal fan as claimed in claim 8, characterised in that: A fixed frame (24) is fixedly installed on the inner side of the rotating seat (21), and a rotating shaft (25) is slidably arranged on the fixed frame (24). The rotating shaft (25) is rotatably installed on the filter screen (19), and a scraper (26) is fixedly installed on the rotating shaft (25). The scraper (26) is attached to the filter surface of the filter screen (19). A switch (27) is fixedly installed on the inner side of the air inlet (3), and the switch (27) is squeezed during the movement of the fixed air inlet pipe (20).

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