Low-noise centrifugal fan

Abstract

The utility model relates to the technical field of centrifugal fans, and discloses a low-noise centrifugal fan which comprises a base, a shell is fixedly connected to the outer wall of the base, a rotor is installed in the shell, a motor is installed on the outer wall of the top of the base, and the tail end of an output shaft of the motor extends into the shell and is fixedly connected with the rotor. The rotor comprises a hub and a plurality of blades evenly distributed on the outer wall of the hub, the front edges of the blades are provided with arc-shaped flow guide edges, the rear edges of the blades are provided with sawtooth grooves, a damping mechanism is installed between the base and the motor, and the base is connected with the motor through the damping mechanism. And starting from the key part of the interaction of the airflow and the impeller, the pneumatic noise and the vortex noise are greatly reduced, and the noise pollution condition during the operation of the fan is effectively improved.

Description

Technical Field

[0001] This application relates to the field of centrifugal fan technology, and in particular to a low-noise centrifugal fan. Background Technology

[0002] Centrifugal fans are machines that rely on input mechanical energy to increase gas pressure and discharge gas. They are widely used in many fields such as industrial production, ventilation, and air conditioning systems. However, in actual use, the noise generated by centrifugal fans during operation has always been a problem that plagues users.

[0003] The main causes of noise generated by traditional centrifugal fans include: aerodynamic noise generated by the friction between the fan impeller and the air during rotation; mechanical noise generated by the vibration of various components during fan operation; and vortex noise formed by unstable airflow inside the fan. These noises not only pollute the working environment and affect the physical and mental health of workers, but may also interfere with the normal lives of nearby residents. Therefore, reducing the noise of centrifugal fans has become an urgent problem to be solved in the industry. Utility Model Content

[0004] The purpose of this invention is to provide a low-noise centrifugal fan to solve the problems mentioned in the background art.

[0005] The low-noise centrifugal fan provided in this application adopts the following technical solution:

[0006] A low-noise centrifugal fan includes a base, an outer shell fixedly connected to the outer wall of the base, a rotor installed inside the outer shell, a motor installed on the top outer wall of the base, and the end of the output shaft of the motor extending into the interior of the outer shell and fixedly connected to the rotor.

[0007] The rotor includes a hub and multiple blades evenly distributed on the outer wall of the hub. The leading edge of the blades is provided with an arc-shaped guide edge, and the trailing edge is provided with a serrated groove. A shock-absorbing mechanism is installed between the base and the motor, and the base and the motor are connected through the shock-absorbing mechanism.

[0008] Preferably, the shock absorption mechanism includes guide rails, a fixing block, and a mounting bracket. Two guide rails are fixedly connected to the top outer wall of the base. Two sliders are slidably connected to the outer wall of the guide rails. A connecting block is fixedly connected to the top outer wall of the slider. A connecting rod is rotatably connected to the top inner wall of the connecting block. The two connecting rods are inclined relative to each other, and their top ends are hinged to the bottom outer wall of the mounting bracket.

[0009] Preferably, the plurality of fixing blocks are welded to the top outer wall of the base, with each pair of fixing blocks located at both ends of the guide rail. A damper is installed between the fixing block and the slider. A sliding rod is fixedly connected to the outer wall of each pair of connecting blocks on opposite sides, and the end of the sliding rod away from the connecting block is slidably connected to the inner wall of the fixing block.

[0010] Preferably, the outer wall of the slide rod is fitted with an elastic element, one end of which is fixedly connected to the outer wall of the fixing block, and the other end is fixedly connected to the outer wall of the connecting block. The motor is fixedly mounted on the top outer wall of the mounting frame by bolts, and a shock-absorbing pad is provided between the mounting frame and the motor.

[0011] Preferably, the bottom outer wall of the mounting bracket is fixedly connected with multiple limiting rods, and the top outer wall of the base is provided with multiple slip rings that communicate with the interior of the base. The limiting rods are slidably connected to the inner wall of the slip rings, and their bottom ends extend into the inner cavity of the base.

[0012] Preferably, the outer wall in the middle of the front side of the housing is provided with an air inlet for air intake, and the outer periphery of the housing is provided with an air outlet for air exhaust.

[0013] In summary, this application includes the following beneficial technical effects:

[0014] 1. This low-noise centrifugal fan features an innovative and optimized impeller structure. The arc-shaped guide edge at the leading edge of the blades effectively guides the airflow smoothly into the fan, significantly reducing airflow separation and lowering the noise generated by the airflow impacting the blades. The serrated groove structure at the trailing edge of the blades effectively disperses the airflow wake vortex, weakens the vortex intensity, and suppresses the noise generated by airflow turbulence. By improving the structure of the leading and trailing edges of the blades, starting from the key parts of the interaction between the airflow and the impeller, aerodynamic noise and vortex noise are significantly reduced, effectively improving the noise pollution situation during fan operation.

[0015] 2. Through the shock absorption mechanism, the elastic element and damping composite shock absorption structure installed between the motor and the base absorb vibration energy and convert it into elastic potential energy through elastic deformation, while the damper consumes vibration energy through the flow of hydraulic oil. The two work together to efficiently attenuate the vibration generated by the motor operation, greatly reducing the noise generated by mechanical vibration, creating a quiet atmosphere for the workplace and surrounding environment, effectively protecting the physical and mental health of the staff, and reducing the noise interference to the lives of surrounding residents. Attached Figure Description

[0016] Figure 1 This is an overall schematic diagram of an embodiment of the application;

[0017] Figure 2 This is a rear-view perspective view of an embodiment of the application;

[0018] Figure 3 for Figure 2 Enlarged schematic diagram of the structure at point A in the middle;

[0019] Figure 4 This is an exploded view of an embodiment of the application;

[0020] Figure 5 for Figure 4 Enlarged schematic diagram of the structure at point B.

[0021] Explanation of reference numerals in the attached drawings: 1. Base; 2. Housing; 3. Air inlet; 4. Air outlet; 5. Motor; 6. Rotor; 7. Hub; 8. Blade; 9. Guide edge; 10. Serrated groove; 11. Slider; 12. Connecting block; 13. Connecting rod; 14. Mounting bracket; 15. Vibration damping pad; 16. Fixing block; 17. Slide rod; 18. Damper; 19. Elastic element; 20. Slip ring; 21. Limiting rod; 22. Guide rail. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0023] This application discloses a low-noise centrifugal fan. (Refer to...) Figure 1-5 A low-noise centrifugal fan includes a base 1, a housing 2, a motor 5, and a rotor 6. The base 1 is integrally formed from high-strength steel and has an anti-slip rubber pad (not shown in the figure) on its bottom. It can be firmly fixed to the ground or equipment platform by expansion bolts to ensure the foundation stability when the fan is running. The housing 2 is fixed to the outer wall of the base 1 by welding (or fixing bolts). The housing 2 adopts a double-layer steel plate structure, and sound-absorbing material is filled between the two layers of steel plates, which can effectively block the noise generated by the fan during operation.

[0024] Reference Figure 4 Inside the outer shell 2, a rotor 6 is installed. The rotor 6 consists of a hub 7 and multiple blades 8 evenly distributed around the outer periphery of the hub 7. The hub 7 is made of aluminum alloy and is formed by precision casting, which has the characteristics of light weight and high strength. The blades 8 are fixedly connected to the hub 7 by high-strength bolts. The leading edge of the blade 8 is precision machined to form an arc-shaped guide edge 9. The curvature of the guide edge 9 is optimized by aerodynamic simulation, which can effectively guide the airflow to flow smoothly into the blade 8. The trailing edge of the blade 8 is machined with a serrated groove 10. The tooth height and tooth spacing of the serrated groove 10 are designed according to a specific ratio, which can effectively disperse the airflow wake vortex.

[0025] Reference Figure 2 and Figure 5 A motor 5 is installed on the top outer wall of the base 1. The motor 5 is a low-noise variable frequency motor. Its output shaft extends into the interior of the housing 2 through a pre-drilled shaft hole (the shaft diameter of the shaft hole is larger than the outer diameter of the output shaft of the motor 5) and is connected to the hub 7 of the rotor 6 by a flat key. This ensures that the power of the motor 5 can be stably transmitted to the rotor 6. At the same time, a shock absorption mechanism is installed between the base 1 and the motor 5. This shock absorption mechanism can effectively absorb the vibration generated by the motor 5 during operation and reduce the generation of mechanical noise.

[0026] Reference Figure 3 The shock absorption mechanism mainly consists of guide rails 22, fixing blocks 16, and mounting brackets 14. Both guide rails 22 are T-shaped guide rails, which are firmly fixed to the top outer wall of the base 1 by welding. The surface of the guide rails 22 is hardened to HRC50-55 to improve wear resistance. Two sliders 11 are slidably installed on the outer wall of the guide rails 22. The sliders 11 and the guide rails 22 are matched with high-precision linear bearings to ensure that the sliders 11 can slide freely with low friction and high precision along the direction of the guide rails 22.

[0027] Reference Figure 3 The top outer wall of the slider 11 is fixed to the connecting block 12 by bolts. The connecting block 12 is made of cast steel and has good strength and toughness. The connecting rod 13 is rotatably connected to the top inner wall of the connecting block 12 by a deep groove ball bearing. The bearing has a precision grade of P5 to ensure that the connecting rod 13 can rotate flexibly and has high rotational accuracy. The two connecting rods 13 are set at relative inclinations, and their top ends are hinged to the bottom outer wall of the mounting frame 14 by a spherical bearing. The spherical bearing can adapt to the force in different directions, forming a stable support structure with multi-directional shock absorption capability.

[0028] Reference Figure 3 Multiple fixing blocks 16 are firmly installed on the top outer wall of the base 1 by welding. Each pair of fixing blocks 16 are located at both ends of the guide rail 22, serving as a limit and support. A damper 18 is installed between the fixing block 16 and the slider 11. The damper 18 is a hydraulic damper, and its two ends are connected to the fixing block 16 and the slider 11 by bolts, which can effectively dissipate vibration energy.

[0029] Reference Figure 3 On the outer wall of each pair of connecting blocks 12 opposite to each other, a sliding rod 17 is fixed by welding. The sliding rod 17 is made of stainless steel and the surface is polished. The inner wall of the fixing block 16 is provided with a sliding groove that matches the sliding rod 17. The end of the sliding rod 17 away from the connecting block 12 is slidably connected in the sliding groove. Precision machining ensures that the sliding rod 17 can slide smoothly in the sliding groove and has a small fitting gap.

[0030] Reference Figure 3 An elastic element 19 is sleeved on the outer wall of the slide rod 17. The elastic element 19 is made of high elastic alloy elastic steel and has undergone heat treatment. Its elastic coefficient meets the design requirements. One end of the elastic element 19 is fixed to the outer wall of the fixing block 16 by welding, and the other end is welded to the outer wall of the connecting block 12. Together with the damper 18, it forms an elastic element damping composite shock absorption structure, which can effectively absorb and attenuate the vibration generated by the motor 5 during operation.

[0031] Reference Figure 2 and Figure 4The motor 5 is fixedly mounted on the top outer wall of the mounting bracket 14 by high-strength bolts. A shock-absorbing pad 15 is provided between the mounting bracket 14 and the motor 5. The shock-absorbing pad 15 is made of rubber and has honeycomb grooves on its surface, which can further enhance the shock absorption effect and reduce the vibration of the motor 5 transmitted to the mounting bracket 14.

[0032] Referring to point 3, multiple limiting rods 21 are welded to the bottom outer wall of the mounting frame 14. The limiting rods 21 are made of cylindrical steel and their surfaces are galvanized to prevent corrosion. Correspondingly, multiple slip rings 20 connected to the interior of the base 1 are opened on the top outer wall of the base 1. The inner diameter of the slip ring 20 and the outer diameter of the limiting rod 21 are clearance-fitted, with the clearance value controlled between 0.05-0.1mm. The limiting rod 21 is inserted into the slip ring 20, allowing the limiting rod 21 to slide within the slip ring 20, and its bottom end extends into the inner cavity of the base 1. Through the cooperation between the limiting rod 21 and the slip ring 20, the offset range of the mounting frame 14 can be effectively limited, ensuring the stability of the mounting frame 14 during the vibration reduction process and preventing excessive offset from affecting the normal operation of the fan.

[0033] Reference Figure 1 and Figure 4 An air inlet 3 is opened on the middle outer wall of the front of the outer casing 2 to guide the air to flow smoothly into the interior of the outer casing 2, reducing air intake resistance and airflow noise. A filter screen (not shown in the figure) can also be installed at the air inlet 3 to filter impurities in the air and prevent impurities from entering the fan and affecting the fan performance. An air outlet 4 is opened on the outer periphery of the outer casing 2. The air outlet 4 is set along the tangential direction of the outer casing 2. When the air is accelerated and pressurized under the action of the blades 8, it is discharged from the air outlet 4 along the tangential direction to form a stable airflow.

[0034] The implementation principle of a low-noise centrifugal fan according to an embodiment of this application is as follows: When the low-noise centrifugal fan is powered on and started, the motor 5 is preferably of type YE2132M-4. The motor 5 is powered on and runs through a switch. The stator winding inside the motor 5 generates a rotating magnetic field, which drives the rotor to rotate, thereby driving the output shaft of the motor 5 to rotate. The output shaft of the motor 5 is connected to the hub 7 of the rotor 6 through a flat key, transmitting power to the rotor 6, causing the hub 7 to drive the blades 8 to rotate at high speed. Outside air enters the interior of the outer casing 2 through the air inlet 3. Under the action of centrifugal force generated by the rotation of the blades 8, the air is thrown towards the outer edge of the blades 8 and flows along the surface of the blades 8 towards the outer periphery of the outer casing 2. The guide edge 9 at the leading edge of the blades 8 can optimize the inflow angle of the airflow, reduce the airflow separation phenomenon, and make the airflow flow more smoothly over the blades 8. The serrated groove 10 at the trailing edge of the blades 8 disperses the airflow wake vortex and reduces the aerodynamic noise caused by airflow turbulence. The accelerated and pressurized air is finally discharged from the air outlet 4 tangentially set along the outer casing 2, forming an airflow with a certain pressure and velocity, which meets the actual requirements. Due to operational requirements, the motor 5 inevitably vibrates during fan operation. This vibration is initially buffered by the damping pad 15, whose rubber material and honeycomb groove structure absorb some of the vibration energy. The remaining vibration energy is transferred to the mounting frame 14, which then transmits the vibration to components such as the connecting rod 13, slider 11, and slide rod 17. At this point, the elastic element 19 undergoes elastic deformation, converting the vibration energy into elastic potential energy, which is then slowly released. Simultaneously, the damper 18 consumes the vibration energy through the flow of internal hydraulic oil. The two work together to effectively absorb and consume the vibration generated by the motor 5 during operation, reducing the transmission of vibration to the base 1 and the outer casing 2, thereby reducing mechanical noise. The limiting rod 21 cooperates with the slip ring 20 to limit the displacement range of the mounting frame 14 when it shifts due to vibration, ensuring that the mounting frame 14 remains stable during vibration damping and preventing loosening or other malfunctions in the connection between the motor 5 and the rotor 6 due to excessive displacement. This ensures that the low-noise centrifugal fan can operate stably and with low noise.

[0035] The foregoing description with reference to preferred embodiments provides an exemplary implementation of the present disclosure. However, those skilled in the art will understand that various modifications and alterations can be made to the above specific embodiments without departing from the spirit of the present disclosure, and various combinations can be made to the various technical features and structures proposed in the present disclosure without exceeding the protection scope of the present disclosure, the protection scope of the present disclosure being determined by the appended claims.

Claims

1. A low-noise centrifugal fan comprising a base (1), characterized in that: The outer wall of the base (1) is fixedly connected to the outer shell (2), the rotor (6) is installed inside the outer shell (2), the top outer wall of the base (1) is equipped with a motor (5), and the end of the output shaft of the motor (5) extends into the interior of the outer shell (2) and is fixedly connected to the rotor (6). The rotor (6) includes a hub (7) and multiple blades (8) evenly distributed on the outer wall of the hub (7). The leading edge of the blade (8) is provided with an arc-shaped guide edge (9), and the trailing edge is provided with a serrated groove (10). A shock-absorbing mechanism is installed between the base (1) and the motor (5). The base (1) and the motor (5) are connected through the shock-absorbing mechanism.

2. A low noise centrifugal fan as claimed in claim 1, characterized in that: The shock absorption mechanism includes a guide rail (22), a fixing block (16), and a mounting bracket (14). The two guide rails (22) are fixedly connected to the top outer wall of the base (1). The outer wall of the guide rail (22) is slidably connected to two sliders (11). The top outer wall of the slider (11) is fixedly connected to a connecting block (12). The top inner wall of the connecting block (12) is rotatably connected to a connecting rod (13). The two connecting rods (13) are inclined relative to each other, and their top ends are hinged to the bottom outer wall of the mounting bracket (14).

3. A low noise centrifugal fan as claimed in claim 2, characterised in that: Multiple fixing blocks (16) are welded to the top outer wall of the base (1). Every two fixing blocks (16) are located at both ends of the guide rail (22). A damper (18) is installed between the fixing block (16) and the slider (11). A sliding rod (17) is fixedly connected to the outer wall of the opposite side of every two connecting blocks (12). The end of the sliding rod (17) away from the connecting block (12) is slidably connected to the inner wall of the fixing block (16).

4. A low noise centrifugal fan as claimed in claim 3, characterised in that: The outer wall of the slide rod (17) is fitted with an elastic element (19). One end of the elastic element (19) is fixedly connected to the outer wall of the fixing block (16), and the other end is fixedly connected to the outer wall of the connecting block (12). The motor (5) is fixedly installed on the top outer wall of the mounting frame (14) by bolts. A shock-absorbing pad (15) is provided between the mounting frame (14) and the motor (5).

5. A low noise centrifugal fan as claimed in claim 2, wherein: The bottom outer wall of the mounting bracket (14) is fixedly connected with multiple limiting rods (21), and the top outer wall of the base (1) is provided with multiple slip rings (20) that communicate with its interior. The limiting rods (21) are slidably connected to the inner wall of the slip rings (20), and their bottom ends extend into the inner cavity of the base (1).

6. A low noise centrifugal fan as claimed in claim 1, wherein: The outer wall of the front of the outer shell (2) is provided with an air inlet (3) for air intake, and the outer periphery of the outer shell (2) is provided with an air outlet (4) for exhaust.

Images