Backward inclined centrifugal fan

Abstract

The utility model discloses a backward-inclined centrifugal fan, and relates to the technical field of fans, the backward-inclined centrifugal fan comprises a fan mounting plate, a motor is mounted on the fan mounting plate, a backward-inclined centrifugal wind wheel is mounted on a rotor of the motor, and the backward-inclined centrifugal wind wheel comprises a front disc, a rear disc and a plurality of blades; an air duct is formed among the front disc, the rear disc and the two adjacent blades, the blades are in the shape of an arc-shaped curved surface in the air duct direction, the air outlet end of each blade is provided with an air pressing inclined surface, and the air inlet end of each blade is provided with a windward arc surface. The air outlet ends of the blades are provided with the air pressing slopes, and the air inlet ends of the blades are provided with the windward cambered surfaces, so that resistance to air is reduced from the air inlet ends, the air channel and the air outlet ends when the blades work, noise of the backward inclined centrifugal fan is reduced, and working efficiency is improved.

Description

Technical Field

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

[0002] Backward-curved centrifugal fans, as a widely used ventilation device, play an important role in industrial and civil fields. Their main function is to increase air pressure through centrifugal force and discharge the air, thereby achieving forced ventilation. With increasingly stringent requirements for noise control in the working environment and growing demands for equipment operating efficiency, how to improve fan efficiency while reducing noise has become one of the key research focuses.

[0003] In existing backward-curved centrifugal fan designs, different impeller structures and installation schemes are often employed to reduce operating noise and improve efficiency. For example, some designs reduce turbulence and vortex generation by changing the blade shape; others focus on improving the airflow guidance structure between the impeller and the casing to reduce wind resistance and improve airflow smoothness. Furthermore, there are various conventional practices for motor mounting and vibration reduction, such as adding anti-vibration pads and installing specialized mounting devices.

[0004] However, these existing technical solutions generally have certain shortcomings. For example, most designs have limited effectiveness in improving blade shape to reduce resistance at the inlet, duct, and outlet, resulting in a failure to significantly reduce noise generated during fan operation despite these measures. The support and guide structures in existing designs also fail to effectively reduce wind resistance, resulting in only a modest improvement in overall efficiency. Utility Model Content

[0005] To help reduce noise generated during fan operation and improve fan efficiency, this application provides a backward-curved centrifugal fan, employing the following technical solution:

[0006] A backward-inclined centrifugal fan includes a fan mounting plate, on which a motor is mounted. A backward-inclined centrifugal impeller is mounted on the rotor of the motor. The backward-inclined centrifugal impeller includes a front plate, a rear plate, and a plurality of blades. An air duct is formed between the front plate, the rear plate, and two adjacent blades. The plurality of blades are arc-shaped curved surfaces along the direction of the air duct. The air outlet end of the blades is provided with a pressure slope, and the air inlet end of the blades is provided with a windward arc surface.

[0007] By adopting the above technical solution, the blades of the backward-curved centrifugal fan are made into arc-shaped surfaces along the air duct direction. The air outlet end of the blades is provided with a pressure slope, and the air inlet end is provided with a windward arc surface. This reduces the resistance to the wind from the air inlet end, the air duct, and the air outlet end during operation, thereby reducing the noise of the backward-curved centrifugal fan and improving its working efficiency.

[0008] Optionally, the fan mounting plate is provided with a mounting slot for mounting the motor, a stop slot communicating with the mounting slot to prevent rotation, and a plurality of mounting holes for mounting the motor are provided at the bottom of the mounting slot.

[0009] By adopting the above technical solution, the fan mounting plate is equipped with mounting slots and holes for mounting the motor, and the stator of the motor is prevented from rotating by the stop slot, which improves the firmness of the motor installation and reduces the noise caused by motor vibration.

[0010] Optionally, the fan mounting plate is further provided with a plurality of support columns, the plurality of support columns being spaced apart from the outer edge of the backward-inclined centrifugal impeller, and the end of the support column away from the fan mounting plate is fixedly mounted with a guide ring mounting plate.

[0011] By adopting the above technical solution, a support column is set on the fan mounting plate, a guide ring mounting plate is installed on the support column, and a guide ring is installed on the guide ring mounting plate, thereby reducing the air resistance of the backward-curved centrifugal impeller. The fan mounting plate and the guide ring mounting plate are fixed together to form the external mounting frame of the backward-curved centrifugal fan, which facilitates the installation and maintenance of the backward-curved centrifugal fan by the user.

[0012] Optionally, the number of the support columns is eight, and the eight support columns are divided into four groups of two support columns each. The four groups of support columns are evenly arranged around the backward-inclined centrifugal impeller, and the support columns in the same group are spaced apart.

[0013] By adopting the above technical solution, the support columns are divided into four groups of two, and the four groups of support columns are evenly arranged around the backward-inclined centrifugal impeller. This helps to improve the strength of the support columns and the reliability of the installation of the guide ring mounting plate. The support columns in the same group are spaced apart, which helps to reduce the resistance to the wind after the wind is discharged from the backward-inclined centrifugal impeller.

[0014] Optionally, the cross-sectional shape of the support column is spindle-shaped, and the length direction of the spindle shape is set along the flow direction of the air discharged from the air duct.

[0015] By adopting the above technical solution, the cross-sectional shape of the support column is set in a shuttle shape with pointed ends and a thick middle, which gives the support column sufficient strength. At the same time, it helps to reduce the resistance to the wind discharged from the backward-inclined centrifugal impeller. The length direction of the shuttle shape is set along the flow direction of the wind discharged from the air duct, thereby further reducing the resistance to the wind.

[0016] Optionally, the guide ring mounting plate is provided with an air guide port connected to the air inlet of the rear-inclined centrifugal impeller, and a back wind groove is provided on the side away from the air guide port. The end of the front plate away from the rear plate passes through the back wind groove.

[0017] By adopting the above technical solution, a back wind groove is set on the side of the guide ring mounting plate away from the air guide port, and the back wind groove is passed through the end of the front plate away from the rear plate, so that the air can directly enter the air inlet of the front plate from the air guide port, which helps to reduce the air leakage between the guide ring mounting plate and the front plate and improves the working efficiency of the rear-inclined centrifugal fan.

[0018] Optionally, the air guide surface of the air guide port of the air guide ring mounting plate is set in an arc shape.

[0019] By adopting the above technical solution, the air guide surface of the air guide port of the air guide ring mounting plate is set in an arc shape, which helps to reduce the resistance of the air inlet to the wind entering the front plate from the air guide port.

[0020] Optionally, the motor includes a rotor, a stator, and a mounting base. The rotor is fixedly connected to the backward-inclined centrifugal impeller, the stator is fixedly mounted on the mounting base, the mounting base is provided with screw holes, the mounting base passes through the mounting groove, and the mounting base is fixedly mounted on the fan mounting plate by fastening screws.

[0021] By adopting the above technical solution, the stator is installed in the mounting slot through the mounting base, and the mounting base is fixed to the fan mounting plate by fastening screws, which helps to improve the convenience and firmness of motor installation.

[0022] Optionally, the mounting base is provided with a stop block, and the stop block passes through the stop groove.

[0023] By adopting the above technical solution, a stop block is set on the mounting base, and the stop block passes through a stop groove, which helps to prevent the mounting base from rotating under the action of external force and improves the reliability of motor operation.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. By making the blades of the backward-curved centrifugal fan into an arc-shaped surface along the air duct direction, and setting a pressure slope at the air outlet end of the blades and a windward arc surface at the air inlet end, the resistance to the wind is reduced from the air inlet end, the air duct and the air outlet end during operation, thereby reducing the noise of the backward-curved centrifugal fan and improving the working efficiency.

[0026] 2. The fan mounting plate is designed with mounting slots and holes for the motor, and the stop slot prevents the motor stator from rotating, which improves the stability of the motor installation and reduces noise caused by motor vibration.

[0027] 3. Support columns are set on the fan mounting plate, and guide ring mounting plates are installed on the support columns. Guide rings are installed on the guide ring mounting plates to reduce the air resistance of the backward-curved centrifugal impeller. The fan mounting plate and the guide ring mounting plate are fixed together to form the external mounting frame of the backward-curved centrifugal fan, which facilitates the installation and maintenance of the backward-curved centrifugal fan by the user.

[0028] 4. The cross-sectional shape of the support column is a shuttle shape with pointed ends and a thicker middle, which gives the support column sufficient strength. At the same time, it helps to reduce the resistance to the air discharged from the backward-inclined centrifugal fan. The length of the shuttle shape is set along the flow direction of the air discharged from the air duct, thereby further reducing the resistance to the wind.

[0029] 5. A backwind groove is provided on the side of the guide ring mounting plate away from the air guide port, and the backwind groove is provided at the end of the front plate away from the rear plate, so that the air can directly enter the air inlet of the front plate from the air guide port. This helps to reduce air leakage between the guide ring mounting plate and the front plate and improves the working efficiency of the rear-inclined centrifugal fan. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a backward-inclined centrifugal fan structure from the front view disclosed in this application.

[0031] Figure 2 This is a cross-sectional view of a backward-inclined centrifugal fan disclosed in this application.

[0032] Figure 3 For along Figure 2 A cross-sectional view along line AA in the middle.

[0033] Figure 4 This is a structural schematic diagram of the wind turbine mounting plate disclosed in this application.

[0034] Figure 5 This is a schematic diagram of the structure of the motor disclosed in this application.

[0035] Figure 6 This is a schematic diagram of a rearward-tilting centrifugal fan structure from the rear view disclosed in this application.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Fan mounting plate; 11. Mounting slot; 12. Stop slot; 13. Mounting hole; 14. Support column; 2. Motor; 21. Rotor; 22. Stator; 23. Mounting base; 231. Screw hole; 232. Stop block; 3. Backward-inclined centrifugal impeller; 31. Front plate; 32. Rear plate; 33. Blades; 331. Compressed air slope; 332. Windward arc surface; 34. Air duct; 4. Guide ring mounting plate; 41. Air guide outlet; 42. Backwind slot; 5. Fastening screws. Detailed Implementation

[0038] The following combination Figures 1 to 6 This application will be described in further detail.

[0039] This application discloses a backward-inclined centrifugal fan.

[0040] A backward-curved centrifugal fan. (See reference) Figures 1 to 3 The system includes a fan mounting plate 1, a motor 2, and a backward-curved centrifugal impeller 3. The motor 2 is mounted on the fan mounting plate 1, and the backward-curved centrifugal impeller 3 is mounted on the rotor 21 of the motor 2. The backward-curved centrifugal impeller 3 includes a front plate 31, a rear plate 32, and several blades 33. An air duct 34 is formed between the front plate 31, the rear plate 32, and two adjacent blades 33. The several blades 33 are curved along the direction of the air duct 34. It should be noted that in this embodiment, the number of blades 33 is 7; in other embodiments of this application, the number of blades 33 is 5, 6, 8, or 9, depending on the backward-curved design. The centrifugal impeller 3 is configured with a pressure slope 331 at the air outlet end and a windward arc surface 332 at the air inlet end. By making the blades 33 of the backward-inclined centrifugal impeller 3 into an arc-shaped surface along the air duct 34, and by setting the pressure slope 331 at the air outlet end and the windward arc surface 332 at the air inlet end, the resistance to the wind is reduced at the air inlet end, the air duct 34 and the air outlet end during operation. This design reduces airflow impact and turbulence, thereby effectively reducing noise levels and improving overall work efficiency.

[0041] Reference Figure 4 The fan mounting plate 1 is provided with a mounting groove 11 and a stop groove 12. The mounting groove 11 is used to install the motor 2. The stop groove 12 is connected to the mounting groove 11 to prevent the stator 22 of the motor 2 from rotating. The bottom of the mounting groove 11 is provided with several mounting holes 13 for installing the motor 2. By setting the mounting groove 11 and mounting holes 13 for installing the motor 2, and by setting the stop groove 12 to prevent the stator 22 of the motor 2 from rotating, the fan mounting plate 1 improves the firmness of the fixed installation of the motor 2 and reduces the noise generated by the vibration of the motor 2.

[0042] Reference Figure 3 and Figure 4The fan mounting plate 1 is also provided with several support columns 14. The support columns 14 are spaced apart from the outer edge of the backward-inclined centrifugal impeller 3. A guide ring mounting plate 4 is fixedly installed on the end of each support column 14 away from the fan mounting plate 1. The fan mounting plate 1 is provided with support columns 14, and the guide ring mounting plate 4 is installed on the support columns 14. It should be noted that the guide ring mounting plate 4 is fixedly installed on the support columns 14. In this embodiment, threaded holes are provided on the support columns 14, and through holes corresponding to the threaded holes are provided on the guide ring mounting plate 4. Then, the guide ring mounting plate 4 is fixed to the support column 14 with screws. In other embodiments of this application, the support column 14 and the guide ring mounting plate 4 can also be fixed by snap-fit ​​or adhesive. Any method that can make the two firmly installed together is acceptable. The guide ring is installed on the guide ring mounting plate 4 to reduce the wind resistance of the backward-inclined centrifugal impeller 3. The fan mounting plate 1 and the guide ring mounting plate 4 are fixed together to form the external mounting frame of the backward-inclined centrifugal fan, which makes it convenient for users to install and maintain the backward-inclined centrifugal fan.

[0043] Reference Figure 3 There are eight support columns 14 in total. The eight support columns 14 are divided into four groups of two support columns 14 each. The four groups of support columns 14 are evenly arranged around the backward-inclined centrifugal impeller 3. The support columns 14 in the same group are spaced apart. The four groups of support columns 14 are evenly arranged around the backward-inclined centrifugal impeller 3, which helps to improve the strength of the support columns 14 and improve the reliability of the installation of the guide ring mounting plate 4. The spaced-apart support columns 14 in the same group helps to reduce the resistance to the wind after the wind is discharged from the backward-inclined centrifugal impeller 3.

[0044] Reference Figure 3 The cross-sectional shape of the support column 14 is spindle-shaped, with its length aligned with the airflow direction discharged from the duct 34. The spindle shape, tapering at both ends and thicker in the middle, provides sufficient strength and helps reduce resistance to the airflow discharged from the backward-inclined centrifugal impeller 3. This shape and orientation not only provide sufficient mechanical strength but also effectively reduce the vortex effect generated when airflow bypasses the support column 14. More importantly, the spindle-shaped design allows airflow to flow smoothly along its surface, unlike traditional cylinders which create a large low-pressure area at the rear, thus preventing additional noise.

[0045] Reference Figure 2The guide ring mounting plate 4 is provided with an air guide port 41 connected to the air inlet of the backward-inclined centrifugal fan 3. A back wind groove 42 is provided on the side away from the air guide port 41. The back wind groove 42 passes through the end of the front plate 31 away from the rear plate 32. The back wind groove 42 is provided on the side of the guide ring mounting plate 4 away from the air guide port 41. The back wind groove 42 passes through the end of the front plate 31 away from the rear plate 32, so that the air can directly enter the air inlet of the front plate 31 from the air guide port 41. This helps to reduce the air leakage between the guide ring mounting plate 4 and the front plate 31 and improves the working efficiency of the backward-inclined centrifugal fan. The air guide surface of the air guide port 41 of the guide ring mounting plate 4 is set with an arc shape, which helps to reduce the resistance to the air entering the air inlet of the front plate 31 from the air guide port 41.

[0046] Reference Figure 2 , Figure 5 and Figure 6 The motor 2 includes a rotor 21, a stator 22, and a mounting base 23. The rotor 21 is fixedly connected to the backward-inclined centrifugal impeller 3. The stator 22 is fixedly mounted on the mounting base 23. The mounting base 23 has screw holes 231 and a mounting groove 11. The mounting base 23 is fixedly mounted on the fan mounting plate 1 by fastening screws 5. The stator 22 is mounted on the mounting groove 11 through the mounting base 23. The mounting base 23 is fixed to the fan mounting plate 1 by fastening screws 5, which helps to improve the convenience and firmness of the motor 2 installation. The mounting base 23 is provided with a stop block 232, which passes through a stop groove 12. The mounting base 23 is provided with a stop block 232, which passes through a stop groove 12. The stop block 232 passes through the stop groove 12, which helps to prevent the mounting base 23 from rotating under the action of external force, thus improving the reliability of the motor 2 operation.

[0047] The implementation principle of this application embodiment is as follows: through careful design and optimization of the curved surface of the blade 33, the shape of the support column 14, and the airflow guiding structure, effective airflow guidance and smooth flow are achieved, thereby significantly reducing the noise during the operation of the fan and improving its working efficiency. At the same time, the unique motor 2 fixing mechanism ensures the reliability and stability of the overall structure, providing a solid guarantee for practical applications.

[0048] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A backward-inclined centrifugal fan, comprising a fan mounting plate (1), a motor (2) mounted on the fan mounting plate (1), and a backward-inclined centrifugal impeller (3) mounted on the rotor (21) of the motor (2), characterized in that: The backward-inclined centrifugal impeller (3) includes a front plate (31), a rear plate (32) and several blades (33). The front plate (31), the rear plate (32) and two adjacent blades (33) form an air duct (34). The shape of the several blades (33) along the direction of the air duct (34) is an arc-shaped surface. The air outlet end of the blade (33) is provided with a pressure slope (331), and the air inlet end of the blade (33) is provided with a windward arc surface (332).

2. A backward-curved centrifugal fan according to claim 1, characterized in that: The fan mounting plate (1) is provided with a mounting groove (11) for mounting the motor (2), and a stop groove (12) for preventing rotation is connected to the mounting groove (11). The bottom of the mounting groove (11) is provided with a plurality of mounting holes (13) for mounting the motor (2).

3. A backward-curved centrifugal fan according to claim 2, characterized in that: The fan mounting plate (1) is also provided with a number of support columns (14), and the number of support columns (14) are spaced apart from the outer edge of the backward-inclined centrifugal impeller (3). The end of the support column (14) away from the fan mounting plate (1) is fixedly installed with a guide ring mounting plate (4).

4. A backward-curved centrifugal fan according to claim 3, characterized in that: The number of the support columns (14) is 8. The 8 support columns (14) are divided into four groups of two support columns (14). The four groups of support columns (14) are evenly arranged around the backward-inclined centrifugal impeller (3). The support columns (14) in the same group are spaced apart.

5. A backward-curved centrifugal fan according to claim 4, characterized in that: The cross-sectional shape of the support column (14) is spindle-shaped, and the length direction of the spindle shape is set along the flow direction of the air discharged from the air duct (34).

6. A backward-curved centrifugal fan according to claim 3, characterized in that: The guide ring mounting plate (4) is provided with an air guide port (41) connected to the air inlet of the rear-inclined centrifugal impeller (3), and a back wind groove (42) is provided on the side away from the air guide port (41). The back wind groove (42) passes through the end of the front plate (31) away from the rear plate (32).

7. A backward-curved centrifugal fan according to claim 6, characterized in that: The air guide surface of the air guide port (41) of the air guide ring mounting plate (4) is set in an arc shape.

8. A backward-curved centrifugal fan according to claim 2, characterized in that: The motor (2) includes a rotor (21), a stator (22) and a mounting base (23). The rotor (21) is fixedly connected to the backward-inclined centrifugal impeller (3). The stator (22) is fixedly mounted on the mounting base (23). The mounting base (23) is provided with screw holes (231). The mounting base (23) passes through the mounting groove (11). The mounting base (23) is fixedly mounted on the fan mounting plate (1) by fastening screws (5).

9. A backward-curved centrifugal fan according to claim 8, characterized in that: The mounting base (23) is provided with a stop block (232), and the stop block (232) passes through the stop groove (12).

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