Improved backward inclined centrifugal wind wheel

Abstract

The utility model discloses an improved retroverted centrifugal wind wheel which comprises an upper cover plate, a bottom plate and a plurality of blades, the upper cover plate, the bottom plate and the blades are integrally formed, and the blades are distributed at intervals in the circumferential direction and connected between the upper cover plate and the bottom plate in a formed mode. Each blade is gradually bent in the clockwise or anticlockwise direction, an included angle beta is formed between the tangent line of any point on a projection curve of each blade and the tangent line of the concentric circle of the centrifugal wind wheel at the point, the included angle beta has the trend of gradually decreasing from the inner edge end to the outer edge end of each blade, the inner edge end of each blade forms an air inlet angle beta 1, and the outer edge end of each blade forms an air outlet angle beta 2. The air inlet angle beta 1 is 35-39 degrees; the outer edge ends of the blades form an air outlet angle beta 2, and the air outlet angle beta 2 ranges from 28 degrees to 32 degrees. And the air inlet resistance is reduced, the air volume capturing efficiency is improved, the air flow discharging direction is optimized, the outlet turbulent flow is reduced, the secondary flow loss is reduced, and the static pressure and energy efficiency ratio is increased.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal fan technology, and in particular to an improved backward-inclined centrifugal impeller. Background Technology

[0002] Current centrifugal fans mainly consist of an impeller, volute, inlet, outlet, and drive unit. Their working principle involves the high-speed rotation of the impeller, which causes the incoming gas to gain kinetic energy under centrifugal force and be thrown against the inner wall of the volute. The gas then gradually decelerates within the volute, increasing in pressure before being discharged through the outlet. As industries increasingly demand higher production efficiency, product quality, and environmental comfort, more stringent requirements are being placed on the performance of centrifugal fans. For example, in data centers and other locations with extremely high heat dissipation requirements, fans need to possess high airflow, high static pressure, and high efficiency to ensure stable operation of electronic equipment in suitable temperature environments. In high-end air purification equipment, fans are required to provide sufficient airflow while also exhibiting low noise and high efficiency, creating a quiet and clean living space for users.

[0003] Existing centrifugal impellers struggle to simultaneously optimize multiple performance indicators such as high air volume, high static pressure, high efficiency, and low noise. Furthermore, some centrifugal impellers employ complex structures and control methods in pursuit of high performance, which not only increases manufacturing costs and complexity but also brings numerous inconveniences to equipment installation, commissioning, and maintenance. Therefore, improvements are necessary. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an improved backward-inclined centrifugal impeller to improve the performance of the impeller, increase the energy efficiency ratio of the fan equipped with the centrifugal impeller, optimize the structure of the impeller, and make it simpler, more reasonable and easier to maintain.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an improved backward-inclined centrifugal impeller, comprising an integrally formed upper cover plate, a bottom plate, and multiple blades, as well as an assembled outer ring. Each blade is spaced apart along the circumference and formed and connected between the upper cover plate and the bottom plate. Each blade is gradually bent in a clockwise or counterclockwise direction. The tangent at any point on the blade's projection curve forms an angle β with the tangent of the concentric circle of the centrifugal impeller at that point. From the inner edge to the outer edge of the blade, the angle β gradually decreases. The inner edge of the blade forms an inlet angle β1, which is 35 to 39 degrees. The outer edge of the blade forms an outlet angle β2, which is 28 to 32 degrees. The inner ring of the outer ring is assembled to the outer edge of the bottom plate. Simultaneously, the outer ring is connected to each blade. The inner surface of the outer ring is smoothly connected to the inner surface of the bottom plate to form a smooth air guide surface structure.

[0006] In a further technical solution, the upper cover is arranged in a ring shape, and the outer diameter D2 of the upper cover is 235-260mm; the inner ring of the upper cover forms an air inlet, and the diameter D1 of the air inlet meets the condition: D1∶D2=0.78±0.05.

[0007] In a further technical solution, the diameter D3 of the outer edge of the outer ring is smaller than the diameter D2, and meets the condition: D3∶D2=0.94±0.05.

[0008] In a further technical solution, the number of blades is 8 to 14.

[0009] In a further technical solution, the blade thickness is 1.2mm-3.5mm and the height is 80mm-95mm; the air inlet and air outlet sides of the blade are narrowed to form a blade designed according to Bernoulli's principle.

[0010] In a further technical solution, the inner side of the base plate is arc-shaped; a connecting pipe is formed at the center of the base plate, and multiple reinforcing ribs are formed between the connecting pipe and the bottom surface of the base plate. Each reinforcing rib is spaced apart along the circumferential direction, and a limiting groove is formed at the inner end of the connecting pipe. The limiting groove is polygonal.

[0011] In a further technical solution, the outer edge of the base plate forms a first step, and the inner ring of the outer ring forms a second step, with the first and second steps spliced ​​together. The inner side of the outer ring has multiple limiting grooves with recesses, and the outer ends of the limiting grooves have limiting slots. The bottom edge of the blade has a limiting protrusion that matches the limiting groove. The bottom of the outer edge of the blade has a downward-protruding limiting foot. During assembly, the limiting protrusion of each blade is engaged with the corresponding limiting groove, and its limiting foot is engaged with the corresponding limiting slot. The connection between the outer ring and the base plate, and the connection between the outer ring and each blade, are fastened by ultrasonic welding.

[0012] The advantages of this invention compared to the prior art after adopting the above structure are:

[0013] 1. It has the advantages of efficient airflow capture and discharge, reduces intake resistance, improves air volume capture efficiency, optimizes airflow discharge direction, reduces outlet turbulence, reduces secondary flow loss, and improves static pressure and energy efficiency ratio.

[0014] 2. The blade tilt angle gradually decreases from the inner edge to the outer edge, achieving a balanced load distribution on the blade, avoiding local stall, and improving the stability of operation under all working conditions.

[0015] 3. The curved blade design effectively suppresses rotational noise and flow separation noise, meeting the low-noise requirements of high-end equipment (such as data centers and air purifiers).

[0016] 4. The limiting snap-fit ​​design between the outer ring and the wind turbine body enables rapid and precise assembly, improving operational efficiency. Ultrasonic welding replaces traditional screws and adhesives, avoiding fatigue failure caused by stress concentration and enhancing the reliability of the connection structure.

[0017] 5. The stepped splicing structure between the outer ring and the base plate ensures a smooth transition of the air guide surface and reduces airflow disturbance. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a structural schematic diagram from another perspective of this utility model.

[0021] Figure 3 This is a side view structural diagram of the present invention.

[0022] Figure 4 This is an exploded view of the present invention.

[0023] Figure 5 This is a cross-sectional schematic diagram of the present invention. Detailed Implementation

[0024] The following are merely preferred embodiments of the present invention and do not limit the scope of protection of the present invention.

[0025] like Figures 1 to 5 As shown, an improved backward-inclined centrifugal impeller includes an upper cover plate 1, a bottom plate 3, and multiple blades 2. The number of blades 2 is 11. The upper cover plate 1, the bottom plate 3, and each blade 2 are integrally formed. Each blade 2 is distributed at intervals along the circumferential direction and is formed and connected between the upper cover plate 1 and the bottom plate 3. Each blade 2 is gradually bent in a clockwise direction. The tangent at any point on the projection curve of the blade 2 and the tangent of the concentric circle of the centrifugal impeller at that point form an angle β. From the inner edge end to the outer edge end of the blade 2, the angle β has a gradually decreasing trend. The inner edge end of the blade 2 forms an air inlet angle β1, which is 35 degrees to 39 degrees. The outer edge end of the blade 2 forms an air outlet angle β2, which is 28 degrees to 32 degrees.

[0026] The upper cover plate 1 is arranged in a ring shape, and the outer diameter D2 of the upper cover plate 1 is 250mm. The inner ring of the upper cover plate 1 forms an air inlet, and the diameter D1 of the air inlet meets the condition: D1∶D2=0.78±0.05, that is, the diameter D1 is 195mm.

[0027] The blade 2 has a maximum thickness of 2.5 mm, a minimum thickness of 1.2 mm, and a height of 85 mm. The air inlet and outlet sides of the blade (2) are narrowed to form a blade (2) designed according to the Bernoulli principle.

[0028] The centrifugal impeller structure provided in this embodiment has the advantages of efficient airflow capture and discharge, reducing intake resistance, improving airflow capture efficiency, optimizing airflow discharge direction, reducing outlet turbulence, reducing secondary flow loss, and improving static pressure and energy efficiency ratio.

[0029] The table below is a performance comparison list of centrifugal fans equipped with the centrifugal impeller in this solution and traditional centrifugal impellers, showing the comparison of various performance indicators when the speed of the two impellers is increased to the same noise level.

[0030]

[0031] Table 1

[0032] As shown in Table 1, when the two types of impellers are accelerated to produce the same noise, the centrifugal impeller in this embodiment, compared with the traditional centrifugal impeller, enhances the airflow capture capability by optimizing the inlet angle β1 through the three-dimensional curved blade shape, thereby increasing the air volume by 12% to 15%; the gradual design of the outlet angle β2 reduces exhaust resistance and improves static pressure efficiency; the optimization of the curvature, thickness, number and height of the blades reduces flow separation loss, improves the overall efficiency of the fan, and at the same time, suppresses turbulent noise.

[0033] The tilt angle of blade 2 gradually decreases from the inner edge to the outer edge, achieving a balanced load distribution on the blade, avoiding local stall, and improving operational stability under all conditions. The bending design of blade 2 effectively suppresses rotational noise and flow separation noise, meeting the low-noise requirements of high-end equipment (such as data centers and air purifiers).

[0034] Specifically, the inner side of the base plate 3 is arc-shaped; a connecting pipe 31 is formed at the center of the base plate 3, and multiple reinforcing ribs 32 are formed and connected between the connecting pipe 31 and the bottom surface of the base plate 3. Each reinforcing rib 32 is spaced apart along the circumferential direction, and a limiting groove 33 is formed at the inner end of the connecting pipe 31. The limiting groove 33 is polygonal.

[0035] Specifically, an outer ring 4 is fitted to the outer edge of the base plate 3. The outer ring 4 is ring-shaped, and its inner ring is connected to the outer edge of the base plate 3. The inner surfaces of the two rings form a smooth air guide surface structure. The inner surfaces of the outer ring 4 are connected to the bottom edges of each blade 2. The diameter D3 of the outer edge of the outer ring 4 is smaller than the diameter D2, and meets the condition: D3∶D2=0.94±0.05. That is, the diameter D3 is 208mm.

[0036] Specifically, the outer edge of the base plate 3 forms a first step 34, and the inner ring of the outer ring 4 forms a second step 41. The first step 34 and the second step 41 are spliced ​​together. The inner surface of the outer ring 4 has multiple limiting grooves 42 recessed, and the outer ends of the limiting grooves 42 have limiting slots 43. The bottom edge of the blade 2 has a limiting protrusion 23, which matches the limiting groove 42. The bottom end of the outer edge of the blade 2 has a downward protruding limiting foot 22. During assembly, the limiting protrusion 23 of each blade 2 is engaged with the corresponding limiting groove 42, and its limiting foot 22 is engaged with the corresponding limiting slot 43. The connection between the outer ring 4 and the base plate 3, and the connection between the outer ring 4 and each blade 2, are fastened by ultrasonic welding. The stepped splicing structure between the outer ring 4 and the base plate 3 ensures a smooth transition of the air guide surface and reduces airflow disturbance.

[0037] The limiting snap-fit ​​design between the outer ring 4 and the wind turbine body enables rapid and precise assembly, improving operational efficiency. Ultrasonic welding replaces traditional screws and adhesives, avoiding fatigue failure caused by stress concentration and enhancing the reliability of its connection structure.

[0038] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. An improved backward-inclined centrifugal impeller, characterized in that: It includes an integrally molded upper cover plate (1), a bottom plate (3), and multiple blades (2), as well as an assembled outer ring (4). Each blade (2) is spaced apart along the circumference and is formed and connected between the upper cover plate (1) and the bottom plate (3). Each blade (2) is gradually bent in either a clockwise or counterclockwise direction. The tangent at any point on the projection curve of the blade (2) forms an angle β with the tangent of the concentric circle of the centrifugal impeller at that point. The angle β gradually decreases from the inner edge to the outer edge of the blade (2). The inner edge of the blade (2) forms an inlet angle β1, which is 35 degrees to 39 degrees. The outer edge of the blade (2) forms an outlet angle β2, which is 28 degrees to 32 degrees. The inner ring of the outer ring (4) is assembled on the outer edge of the base plate (3). At the same time, the outer ring (4) is connected to each blade. The inner side of the outer ring (4) is smoothly connected to the inner side of the base plate (3) to form a smooth air guide surface structure.

2. An improved backward-inclined centrifugal impeller according to claim 1, characterized in that: The upper cover plate (1) is arranged in a ring shape, and the outer diameter D2 of the upper cover plate (1) is 235-260mm; the inner ring of the upper cover plate (1) forms an air inlet, and the diameter D1 of the air inlet meets the condition: D1∶D2=0.78±0.

05.

3. An improved backward-inclined centrifugal impeller according to claim 2, characterized in that: The outer diameter D3 of the outer ring (4) is smaller than the diameter D2, and meets the condition: D3∶D2=0.94±0.

05.

4. An improved backward-inclined centrifugal impeller according to claim 3, characterized in that: The number of blades (2) is 8 to 14.

5. An improved backward-inclined centrifugal impeller according to claim 4, characterized in that: The blade (2) has a thickness of 1.2mm-3.5mm and a height of 80mm-95mm; the air inlet side and air outlet side of the blade (2) are narrowed to form a blade (2) designed according to the Bernoulli principle.

6. An improved backward-inclined centrifugal impeller according to claim 5, characterized in that: The inner side of the base plate (3) is arc-shaped; a connecting pipe (31) is formed at the center of the base plate (3), and multiple reinforcing ribs (32) are formed and connected between the connecting pipe (31) and the bottom surface of the base plate (3). Each reinforcing rib (32) is spaced apart along the circumferential direction. A limiting groove (33) is formed at the inner end of the connecting pipe (31), and the limiting groove (33) is polygonal.

7. An improved backward-inclined centrifugal impeller according to claim 1, characterized in that: The outer edge of the base plate (3) forms a first step (34), and the inner ring of the outer ring (4) forms a second step (41). The first step (34) and the second step (41) are spliced ​​together. The inner side of the outer ring (4) is notched with multiple limiting grooves (42). The outer end of the limiting grooves (42) is provided with a limiting slot (43). The bottom edge of the blade (2) is formed with a limiting protrusion (23). The limiting protrusion (23) matches the limiting groove (42). The bottom end of the outer edge of the blade (2) is formed with a downward protruding limiting foot (22). During assembly, the limiting protrusion (23) of each blade (2) is respectively engaged with the corresponding limiting groove (42), and its limiting foot (22) is engaged with the corresponding limiting slot (43). The connection between the outer ring (4) and the base plate (3) and the connection between the outer ring (4) and each blade (2) are fastened by ultrasonic welding.

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