Single-suction type centrifugal impeller with one-way twisted blades and fan

Abstract

The single-suction type centrifugal impeller comprises the blades, a concave face and a convex face are formed at the upper end and the lower end of each blade respectively, the concave faces and the convex faces extend in the length direction of the blades, and a positive deflection blade top and a negative deflection blade root are arranged at the two axial ends of each blade respectively; a front edge is formed at the concave position along the axial height of a blade channel of the blade, a rear edge is formed at the convex position along the axial height of the blade channel of the blade, and the blade is further provided with an air inlet and an air outlet. The centrifugal fan blade solves the technical problems that in the prior art, traditional centrifugal fan blades are designed in a linear mode or a simple bending mode, so that the working efficiency is low in the actual using process, and noise is large in the using process.

Description

Technical Field

[0001] The invention relates to the technical field of fans, and in particular to a single-suction centrifugal impeller with unidirectional twisted blades and a fan. Background Art

[0002] In modern industry and construction, centrifugal fans are widely used in air treatment and airflow control. Their main function is to push the airflow from the center of the fan to the periphery through the rotating impeller, thereby increasing the pressure and flow of the airflow.

[0003] In the Chinese patent application document CN115596702A, a "centrifugal impeller, centrifugal fan and air conditioning unit" is proposed. The device includes a hub, a centrifugal fan blade, which is installed on the hub; a fixing ring, which is connected to the radial outer side of the air inlet end of the centrifugal fan blade; and a reinforcing part, which is connected between the centrifugal fan blade and the fixing ring. The centrifugal fan and the air conditioning unit respectively include the centrifugal impeller. The device can improve the strength of the connection position between the centrifugal fan blade and the fixing ring, and increase the operating speed of the centrifugal impeller;

[0004] In the Chinese patent application document CN116464666A, a "centrifugal impeller and centrifugal fan" is proposed. The device includes a bottom plate, a top plate and a plurality of blades uniformly arranged along the circumferential direction of the axis of the top plate and the bottom plate and all located between the bottom plate and the top plate. The blade has a leading edge, a blade root, a trailing edge and a blade tip. The leading edge and the trailing edge are arranged oppositely, and the blade root and the blade tip are arranged oppositely. In the direction from the blade root to the blade tip, the blade includes a mainstream area and a jet area, a part of the leading edge is located in the mainstream area, and the other part is located in the jet area. The direction of the relative speed of the airflow flowing into the centrifugal impeller and the blade is opposite to the rotation speed of the leading edge located in the mainstream area to form an inlet angle β1, and the direction of the relative speed of the airflow and the blade is opposite to the rotation speed of the leading edge located in the jet area to form an inlet angle β2. During the rotation of the centrifugal impeller, the inlet angle β1 gradually decreases, and the inlet angle β2 gradually increases.

[0005] At present, traditional centrifugal fan impellers usually adopt straight or simply curved blade designs; although these blades have certain performance advantages, they have problems such as insufficient efficiency, high noise and unstable airflow in actual applications. Summary of the invention

[0006] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide a single-suction centrifugal impeller and fan with unidirectional twisted blades, so as to solve the technical problems that traditional centrifugal fan blades in the prior art all adopt a straight line or simple curved design, which leads to low working efficiency and high noise during actual use.

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a unidirectional twisted blade, comprising a blade, wherein a concave surface and a convex surface are respectively formed at the upper and lower ends of the blade, the concave surface and the convex surface extend along the length direction of the blade, and a positive deflection blade top and a negative deflection blade root are respectively arranged at the axial ends of the blade; a leading edge is formed at a recessed position along the axial height of the blade channel, and a trailing edge is formed at a raised position along the axial height of the blade channel, and an air inlet and an air outlet are also respectively arranged on the blade.

[0009] In some embodiments, the concave surface is a suction wall surface, and the convex surface is a pressure wall surface. The suction wall surface and the pressure wall surface are arranged opposite to each other on the blade, and both extend along the length direction of the blade.

[0010] In some embodiments, the positive deflection blade tip deflects clockwise and gradually reduces the deflection angle along the axial height of the blade path until the negative deflection blade root deflects counterclockwise.

[0011] In some embodiments, the blade is also provided with an inlet angle and an outlet angle that cooperate with the air inlet and the air outlet, and the inlet angle of the air inlet gradually decreases along the axial height of the blade, and the outlet angle of the air outlet gradually increases along the axial height of the blade path.

[0012] In some embodiments, the air inlet on the suction wall surface is gradually recessed along the axial height of the blade channel, and the air outlet on the pressure wall surface is gradually protruded along the axial height of the blade channel.

[0013] In some embodiments, the rotation center point of the shape change of the cross-sectional shape on the blade and along the axial height of the blade path from the positive deflection blade top to the negative deflection blade root is point R, and any cross-sectional contour shape of the blade along the axial height of the blade path remains consistent, that is, the shape of the positive deflection blade top and the negative deflection blade root are the same, the positive deflection blade top rotates clockwise relative to the original blade top, and the negative deflection blade root rotates counterclockwise relative to the original blade root.

[0014] In some embodiments, the deflection angle range of the positive deflection blade top is 0°-4°, the deflection angle of the negative deflection blade root is -4°-0°, the inner and outer circle diameters of the positive deflection blade top are both increased by 0-1.5mm, and the inner and outer circle diameters of the negative deflection blade root are both reduced by 0-1.5mm, the inlet angle is the angle β1 between the blade and the circumferential direction when entering the blade, and the range of the inlet angle is 70°-85°; the outlet angle is the angle β2 between the blade and the circumferential direction when leaving the blade, and the range of the outlet angle is 160°-175°.

[0015] A single-suction centrifugal impeller, the centrifugal impeller comprises a main shaft, an air outlet fixed wheel end and a bottom fixed wheel disc; an installation area is formed between the air outlet fixed wheel end and the bottom fixed wheel disc, and the main shaft is arranged on the outside of the bottom fixed wheel disc, a rotation axis is arranged at the axis center of the main shaft, a plurality of blades are arranged in the installation area along the rotation axis at uniform intervals, and the two ends of the blades are respectively connected to the opposite side of the air outlet fixed wheel end and the bottom fixed wheel disc, wherein the length of the blade is parallel to the rotation axis, and the leading edge of the blade is closer to the rotation axis than the trailing edge thereof.

[0016] A centrifugal fan comprises a driving motor, a volute body and a volute bracket; the output end of the driving motor is connected to the main shaft, the volute body is provided with a mounting cavity, a centrifugal impeller is arranged in the mounting cavity, the volute body is also provided with an air outlet, and the lower end of the volute body is provided with a volute bracket.

[0017] In some embodiments, a wind collector cooperating with the centrifugal impeller is provided on the volute body, and the wind collector is tightly connected with a sealing baffle, a bearing is provided at one end of the main shaft away from the drive motor, a volute tongue is also provided on the volute body, and a support frame is provided at the lower end of the drive motor.

[0018] Compared with the prior art, the present invention provides a single-suction centrifugal impeller and a fan with unidirectional twisted blades. When the blade is applied to a single-suction centrifugal impeller, the blade tip design at the air outlet fixed wheel end has the feature of a positive deflection blade tip. During the operation of the fan, this design can significantly optimize the guidance and flow characteristics of the airflow on the one hand. Specifically, the design effectively accelerates the speed of the airflow injected from the impeller air collecting port into the blade duct flow channel by implementing a clockwise positive deflection on the blade tip part, so that the airflow flows more smoothly into the flow channel area of ​​the blade, which not only reduces the turbulence and resistance during the airflow entry process, but also reduces the vibration problem caused by the impact of the airflow, thereby improving the overall operation efficiency of the fan. On the other hand, the optimized design of the positive deflection angle ensures that the airflow can be more evenly distributed when passing through the blade, further enhancing the airflow stability and conveying capacity of the fan. The blade has the feature of a negative deflection blade root in the blade root design of the bottom fixed wheel disc. This arrangement can effectively guide the airflow away from the blade during the operation of the fan. The root area of ​​the blade is avoided to avoid a large amount of airflow accumulation at the blade root. This helps to reduce the accumulation of airflow at the blade root, avoids the problem of airflow instability caused by airflow accumulation, avoids turbulence and eddy current caused by the increase of local flow resistance, improves the overall efficiency, and reduces the uneven airflow load on the blade surface; on the other hand, the negative deflection blade root setting can achieve a more uniform airflow distribution and a smoother airflow transition. The airflow in the blade root area is effectively guided, thereby avoiding the stagnation of airflow at the root of the blade, reducing the local pressure loss when the airflow passes through the blade root area, and further improving the comprehensive aerodynamic performance and efficiency of the fan; compared with the existing centrifugal fan, the present invention provides a drive motor that is externally placed outside the fan, which effectively reduces the overall volume and weight of the fan. In addition, the use of a drive motor with an outer rotor structure further optimizes the dynamic balance and operating stability of the fan, reduces mechanical vibration and noise, and this improvement not only improves the energy efficiency ratio of the fan, but also provides greater flexibility and convenience for the maintenance and installation of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is an overall schematic diagram of a unidirectional twisted blade provided by an embodiment of the present invention;

[0020] Figure 2 is a side view schematic diagram of a unidirectional twisted blade provided by an embodiment of the present invention;

[0021] Figure 3 is an overall schematic diagram of a centrifugal impeller provided by an embodiment of the present invention;

[0022] Figure 4 is an internal schematic diagram of a centrifugal impeller provided by an embodiment of the present invention;

[0023] Figure 5It is a schematic diagram of the assembly of a centrifugal impeller and a volute body provided by an embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of the expansion of the centrifugal impeller and the volute body provided by an embodiment of the present invention;

[0025] Figure 7 is an overall schematic diagram of a fan provided by an embodiment of the present invention;

[0026] Figure 8 It is a schematic diagram of the back structure of a fan provided by an embodiment of the present invention.

[0027] Explanation of the reference numerals: 1. blade; 11. suction wall; 12. pressure wall; 13. positive deflection blade top; 14. negative deflection blade root; 15. leading edge; 16. trailing edge; 17. air inlet; 18. air outlet; 19. point R; 2. centrifugal impeller; 21. main shaft; 211. rotation axis; 22. air outlet fixed wheel end; 23. bottom fixed wheel disc; 3. centrifugal fan; 31. drive motor; 311. support frame; 32. volute body; 321. installation cavity; 322. air outlet end; 33. volute bracket; 34. air collector; 35. sealing baffle; 36. bearing; 37. volute tongue. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] In order to solve the technical problem that traditional centrifugal fan blades in the prior art all adopt a straight line or a simple curved design, which leads to low working efficiency and high noise during actual use, the present invention provides a single-suction centrifugal impeller and fan with unidirectional twisted blades, which can improve the operating efficiency of the fan and reduce the noise generated during the operation of the fan.

[0030] It should be noted that the single-suction centrifugal impeller and fan with unidirectional twisted blades described in the present invention are used for but not limited to the fan field, etc. For the convenience of explanation, in the present invention, only the single-suction centrifugal impeller and fan with unidirectional twisted blades applied to the fan field are used as an example for explanation, and the principles of applying the single-suction centrifugal impeller and fan with unidirectional twisted blades in other types of equipment are essentially the same as those applied in the fan field, and will not be described one by one here.

[0031] See also Figure 1 , Figure 1The present invention is a schematic structural diagram of a single-suction centrifugal impeller and a fan with unidirectional twisted blades in an embodiment of the present invention. A unidirectional twisted blade comprises a blade 1, wherein a concave surface and a convex surface are respectively formed at the upper and lower ends of the blade 1, and the concave surface and the convex surface extend along the length direction of the blade 1. A positive deflection blade top 13 and a negative deflection blade root 14 are respectively provided at the axial ends of the blade 1; a leading edge 15 is formed at a recessed portion along the axial height of the blade channel of the blade 1, and a trailing edge 16 is formed at a raised portion along the axial height of the blade channel of the blade 1, and an air inlet 17 and an air outlet 18 are also respectively provided on the blade 1.

[0032] In this embodiment, the blade top is provided with a positive deflection and the blade root is provided with a negative deflection; specifically, the deflection angle of the blade top gradually increases from 0° clockwise to 4°, then decreases back to 0°, and then increases in a counterclockwise direction, and finally reaches a deflection angle of -4° to 0° at the blade root. This arrangement enables the clockwise deflection at the top of the blade 1 to significantly optimize the guidance of the airflow, improve the flow characteristics of the airflow, and thus provide better directionality when the airflow enters the centrifugal impeller 2, which helps to reduce turbulence and noise, while the counterclockwise deflection at the root of the blade 1 effectively guides the airflow away from the root of the blade 1, reducing the accumulation of airflow in the blade root area. This arrangement is intended to improve the overall aerodynamic performance, reduce the instability of the airflow, and improve the working efficiency of the blade 1.

[0033] In one embodiment, see Figure 1 and Figure 2In order to improve the working efficiency of the blade 1, the concave surface is the suction wall surface 11, and the convex surface is the pressure wall surface 12. The suction wall surface 11 and the pressure wall surface 12 are arranged opposite to each other on the blade 1, and the two extend along the length direction of the blade 1. The positive deflection blade top 13 deflects clockwise along the axial height of the blade path of the blade 1 and gradually reduces the deflection angle until the negative deflection blade root 14 deflects counterclockwise. The blade 1 is also provided with an inlet angle and an outlet angle that cooperate with the air inlet 17 and the air outlet 18, and the inlet angle of the air inlet 17 along the axial height of the blade 1 gradually decreases, and the outlet angle of the air outlet 18 along the axial height of the blade path of the blade 1 gradually increases. The air inlet 17 on the suction wall surface 11 is gradually recessed along the axial height of the blade path of the blade 1, and the air outlet 18 on the pressure wall surface 12 is gradually convex along the axial height of the blade path of the blade 1. The blade 1 and along the axial height of the blade path from the positive deflection blade top 13 to the negative deflection blade root 1 The rotation center point of the shape change of the cross-sectional shape of 4 is R point 19, and the cross-sectional contour shape of any blade 1 along the axial height of the blade path remains consistent, that is, the shape of the positive deflection blade top 13 and the negative deflection blade root 14 are the same, the positive deflection blade top 13 rotates clockwise relative to the original blade top, and the negative deflection blade root 14 rotates counterclockwise relative to the original blade root, the deflection angle range of the positive deflection blade top 13 is 0°-4°, and the deflection angle of the negative deflection blade root 14 is -4°-0°, the inner and outer circle diameters of the positive deflection blade top 13 are increased by 0-1.5mm, and the inner and outer circle diameters of the negative deflection blade root 14 are reduced by 0-1.5mm, the inlet angle is the angle β1 between the blade 1 and the circumferential direction when entering the blade 1, and the range of the inlet angle is 70°-85°; the outlet angle is the angle β2 between the blade 1 and the circumferential direction when leaving the blade 1, and the range of the outlet angle is 160°-175°.

[0034] In the present embodiment, a positive deflection blade top 13 and a negative deflection blade root 14 are provided on the blade 1, which can effectively speed up the speed of the airflow injected into the pipe flow channel of the blade 1 from the air collecting port of the centrifugal impeller 2, so that the airflow can flow more smoothly into the flow channel area of ​​the blade 1, which not only reduces the turbulence and resistance during the airflow entry process, but also reduces the vibration problem caused by the impact of the airflow. The blade 1 designed in this way can improve the overall operating efficiency of the entire centrifugal fan 3. The positive deflection blade top 13 improves the performance of the blade 1 by changing the shape of the top of the blade 1, effectively reducing the airflow separation at the top of the blade 1, thereby improving the efficiency and performance of the blade 1. The positive deflection blade top 13 can reduce the airflow separation at the top of the blade 1, thereby improving the efficiency of the blade 1. This is because the positive deflection blade top 13 can make the airflow at the top of the blade 1 smoother, reduce the disturbance and energy loss of the airflow, and the positive deflection blade top 13 can also reduce the noise of the blade 1; because the positive deflection blade top 13 can reduce the airflow separation at the top of the blade 1 , thereby reducing the disturbance and noise of the airflow. The positive deflection blade top 13 can also extend the service life of the blade 1, because the positive deflection blade top 13 can reduce the airflow separation at the top of the blade 1, thereby reducing the wear and damage of the blade 1, and setting the negative deflection blade root 14 can reduce the load on the root of the fan blade 1, thereby reducing the stress and fatigue damage at the root of the blade 1 and extending the service life of the blade 1. The negative deflection blade root 14 can improve the dynamic response of the centrifugal fan 3, improve the stability and reliability of the centrifugal fan 3, and reduce the damage risk of the centrifugal fan 3 under extreme wind conditions. The negative deflection blade root 14 can also simplify the manufacturing process of the fan, reduce the manufacturing cost, and improve the economy of the centrifugal fan 3. The negative deflection blade root 14 can improve the aerodynamic performance of the centrifugal fan 3 and improve the power generation efficiency of the centrifugal fan 3, thereby improving the economic benefits of the centrifugal fan 3. The negative deflection blade root 14 can make the centrifugal fan 3 better adapt to complex wind conditions, such as strong winds, gusts, etc., and improve the adaptability and reliability of the fan.

[0035] In one embodiment, see Figure 3 - Figure 5 In order to improve the working efficiency of the centrifugal impeller 2, the centrifugal impeller 2 includes a main shaft 21, an air outlet fixed wheel end 22 and a bottom fixed wheel disc 23; an installation area is formed between the air outlet fixed wheel end 22 and the bottom fixed wheel disc 23, and the main shaft 21 is arranged on the outer side of the bottom fixed wheel disc 23, and a rotation axis 211 is arranged at the axis center of the main shaft 21, and a plurality of blades 1 are evenly spaced and arranged in the installation area along the rotation axis 211, and the two ends of the blade 1 are respectively connected to the opposite side of the air outlet fixed wheel end 22 and the bottom fixed wheel disc 23, wherein the length of the blade 1 is parallel to the rotation axis 211, and the leading edge 15 of the blade 1 is smaller than the distance between its trailing edge 16 and the rotation axis 211.

[0036] In this embodiment, the centrifugal fan 3 adopts a new blade 1 for structural design, which has high stability, so that it will not malfunction during long-term operation, and the noise is low during operation, and it will not cause interference to the surrounding environment and staff; this makes them suitable for places that require a quiet working environment, such as offices, hospitals, etc. When the centrifugal impeller 2 is installed on the centrifugal fan 3, when the centrifugal fan 3 is running, on the one hand, it can significantly optimize the guidance and flow characteristics of the airflow, and by implementing a clockwise positive deflection on the top part of the blade 1, the speed of the airflow injected from the air collecting port of the centrifugal impeller 2 to the pipeline flow channel of the blade 1 is effectively accelerated, so that it flows more smoothly into the flow channel area of ​​the blade 1, which not only reduces the turbulence and resistance during the airflow entry process, but also reduces the vibration problem caused by the impact of the airflow, thereby improving the overall operation efficiency of the centrifugal fan 3; on the other hand, the optimized design of the positive deflection angle ensures that the airflow can be more evenly distributed when passing through the blade 1, further enhancing the airflow stability and conveying capacity of the centrifugal fan 3.

[0037] In one embodiment, see Figure 5 - Figure 8 In order to improve the working efficiency of the centrifugal fan 3, the centrifugal fan 3 includes a driving motor 31, a volute body 32 and a volute bracket 33; the output end of the driving motor 31 is connected to the main shaft 21, the volute body 32 is provided with a mounting cavity 321, and the mounting cavity 321 is provided with a centrifugal impeller 2, the volute body 32 is also provided with an air outlet end 322, the lower end of the volute body 32 is provided with a volute bracket 33, the volute body 32 is provided with an air collector 34 that cooperates with the centrifugal impeller 2, and the air collector 34 is tightly connected with a sealing baffle 35, a bearing 36 is provided at one end of the main shaft 21 away from the driving motor 31, a volute tongue 37 is also provided on the volute body 32, and a support frame 311 is provided at the lower end of the driving motor 31.

[0038] In this embodiment, the drive motor 31 is externally arranged outside the fan, so that the overall volume and weight of the fan are effectively reduced. In addition, the use of the outer rotor drive motor 31 further optimizes the dynamic balance and operation stability of the fan, and reduces mechanical vibration and noise. This improvement not only improves the energy efficiency ratio of the fan, but also provides greater flexibility and convenience for the maintenance and installation of the fan. The main function of the air collector 34 is to evenly guide the airflow to the centrifugal impeller 2 to reduce the resistance loss of the airflow and ensure that the airflow can smoothly enter the centrifugal impeller 2. At the same time, it has the effect of improving the overall performance of the centrifugal fan 3 and reducing the noise generated during the operation of the centrifugal fan 3. The main function of the sealing baffle 35 is to prevent gas or liquid from leaking inside the fan, ensuring the normal operation and efficiency of the centrifugal fan 3, and at the same time can reduce the energy loss inside the fan, improve the efficiency of the centrifugal fan 3, and protect the fan from the influence of the external environment, thereby extending the service life of the centrifugal fan 3. It also has the effect of reducing the noise and vibration inside the centrifugal fan 3 and improving the working environment.

[0039] In order to better understand the present invention, the following Figures 1 to 8 The technical solution of the present invention is described in detail: by setting a suction wall 11 and a pressure wall 12 on the blade 1, when the fan is running, the air flows through the blade 1, and due to the shape and rotation of the blade 1, the air forms a low-pressure area on the side of the suction wall 11 of the blade 1, and this low-pressure area will attract the surrounding air, thereby generating suction; at the same time, when the centrifugal fan 3 is running, the air flows through the blade 1, and due to the shape and rotation of the blade 1, the air forms a high-pressure area on the side of the pressure wall 12 of the blade 1, and this high-pressure area will push the air to flow forward, thereby generating thrust. The blade 1 in this application is a single twisted structure, and each cross section is deflected on the original basis, and the deflection center point is point R 19, The blade tip is provided with a positive deflection, and the blade root is provided with a negative deflection; the deflection angle of the blade tip gradually increases from 0° clockwise to 4°, then decreases back to 0°, and then increases in a counterclockwise direction, and finally reaches a deflection angle of -4° to 0° at the blade root. By setting it in this way, the clockwise deflection at the top of the blade 1 significantly optimizes the guidance of the airflow, improves the flow characteristics of the airflow, and thus provides better directionality when the airflow enters the impeller, which helps to reduce turbulence and noise, while the counterclockwise deflection at the root of the blade 1 effectively guides the airflow away from the root of the blade 1, reduces the accumulation of the airflow in the blade root area, effectively improves the overall aerodynamic performance, reduces the instability of the airflow, and improves the working efficiency of the blade 1;

[0040] The centrifugal impeller 2 in the present application is the core structural component of the centrifugal fan 3, which includes an air outlet fixed wheel end 22, blades 1 and a bottom fixed wheel disc 23. The centrifugal impeller 2 has a vital influence on the air volume and efficiency of the centrifugal fan 3. The aerodynamic performance of the centrifugal impeller 2 determines the air flow guidance efficiency and the overall working efficiency of the fan; through the blades 1 with a twisted angle in the present application, the air flow introduction speed can be significantly improved, and the local accumulation of air flow at the root of the blade can be effectively prevented, the flow path of the air flow is optimized, thereby reducing aerodynamic losses, enhancing aerodynamic performance and the working efficiency of the fan, and the volute body 32 and the volute tongue 37 in the device are tightly combined to form a whole, without an additional volute tongue 37 part, this structure helps to improve the fluid dynamics performance, reduce turbulence and energy loss to improve the overall efficiency of the system, and by eliminating the separation seams that may exist in the traditional design, the structure can improve the smooth flow of the fluid, thereby enhancing the overall performance and stability of the fluid system;

[0041] The air inlet 17 of the centrifugal fan 3 is provided with an air collector 34, and a sealing baffle 35 is installed on the periphery of the air collector 34, which effectively blocks the gap between the volute body 32 and the air collector 34, and ensures the stability of the airflow by preventing airflow leakage or backflow. The configuration of the sealing baffle 35 not only reduces noise, but also reduces energy loss, thereby optimizing the overall performance of the system, improving the fluid dynamics efficiency, and further improving the operating efficiency and reliability of the fan system;

[0042] In the present application, the drive motor 31 is fixedly arranged on the outside of the centrifugal fan 3, and the drive motor 31 is configured as an outer rotor motor. The main shaft 21 of the drive motor 31 is connected to the centrifugal impeller 2 through a bearing 36. The drive motor 31 transmits power to the centrifugal impeller 2 by applying a driving force to the main shaft 21, thereby improving the dynamic balance and operation stability of the centrifugal fan 3. By placing the drive motor 31 outside the centrifugal fan 3, the overall volume and weight of the centrifugal fan 3 are effectively reduced, and the design layout of the centrifugal fan 3 is optimized. This configuration makes the power transmission path between the drive motor 31 and the centrifugal impeller 2 shorter, thereby reducing power loss and improving transmission efficiency; in addition, the use of the drive motor 31 further improves the dynamic balance of the centrifugal fan 3, because the drive motor 31 has a better center of gravity distribution, which helps to reduce vibration caused by imbalance; the external design of the drive motor 31 reduces interference with the internal structure of the centrifugal fan 3, thereby improving the operation stability of the centrifugal fan 3, and by reducing mechanical vibration and noise, the comfort and quietness of the centrifugal fan 3 in actual application are improved.

[0043] Specifically, the improved design not only improves the energy efficiency ratio of the fan, so that it can provide higher air flow or pressure under the same energy input, but also simplifies the maintenance and installation process of the centrifugal fan 3; the external design of the drive motor 31 makes it unnecessary to disassemble the complex components inside the centrifugal fan 3 when repairing and replacing the motor, thereby improving the maintenance efficiency. At present, the airflow distribution of traditional fans is usually not uniform, which will lead to reduced fan efficiency, and because the flow path of the airflow may be irregular, the difference in airflow velocity between the leading edge 15 and the trailing edge 16 of the blade 1 makes the fan perform poorly in actual operation. The present application optimizes the guidance and distribution of the airflow by designing a blade 1 with a specific twist angle, thereby improving the uniformity of the airflow, allowing the airflow to pass through the impeller more smoothly and reducing the instability of the flow. In addition, the root of the impeller blade 1 of the traditional fan is prone to airflow accumulation, which will lead to an increase in aerodynamic resistance, thereby affecting the performance of the fan, and the blade 1 in the present application effectively reduces this airflow accumulation problem. By improving the airflow path, the twisted blade 1 can more effectively guide the airflow, reduce aerodynamic losses, and greatly improve the aerodynamic efficiency of the fan.

[0044] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A unidirectional twisted blade, characterized in that: It includes a blade, wherein a concave surface and a convex surface are respectively formed at the upper and lower ends of the blade, the concave surface and the convex surface extend along the length direction of the blade, and a positive deflection blade top and a negative deflection blade root are respectively arranged at the two axial ends of the blade; a leading edge is formed at a recessed position along the axial height of the blade channel, and a trailing edge is formed at a raised position along the axial height of the blade channel, and an air inlet and an air outlet are also respectively arranged on the blade.

2. The one-way twisted blade according to claim 1, characterized in that: The concave surface is a suction wall surface, and the convex surface is a pressure wall surface. The suction wall surface and the pressure wall surface are arranged opposite to each other on the blade, and both extend along the length direction of the blade.

3. The one-way twisted blade according to claim 1, characterized in that: The positive deflection blade tip deflects clockwise and gradually reduces the deflection angle along the axial height of the blade path until the negative deflection blade root deflects counterclockwise.

4. The one-way twisted blade according to claim 1, characterized in that: The blade is also provided with an inlet angle and an outlet angle that match the inlet and the outlet, and the inlet angle of the inlet gradually decreases along the axial height of the blade, and the outlet angle of the outlet gradually increases along the axial height of the blade.

5. The one-way twisted blade according to claim 2, characterized in that: The air inlet on the suction wall surface is gradually recessed along the axial height of the blade channel, and the air outlet on the pressure wall surface is gradually protruded along the axial height of the blade channel.

6. The one-way twisted blade according to claim 1, characterized in that: The rotation center point of the shape change of the cross-sectional shape on the blade from the positive deflection blade top to the negative deflection blade root along the axial height of the blade path is point R, and the cross-sectional contour shape of the blade along any axial height of the blade path remains consistent, that is, the shape of the positive deflection blade top and the negative deflection blade root are the same, the positive deflection blade top rotates clockwise relative to the original blade top, and the negative deflection blade root rotates counterclockwise relative to the original blade root.

7. The one-way twisted blade according to claim 6, characterized in that: The deflection angle range of the positive deflection blade top is 0°-4°, the deflection angle of the negative deflection blade root is -4°-0°, the inner and outer circle diameters of the positive deflection blade top are both increased by 0-1.5mm, and the inner and outer circle diameters of the negative deflection blade root are both reduced by 0-1.5mm. The wind inlet angle is the angle β1 between the blade and the circumferential direction when entering the blade, and the range of the wind inlet angle is 70°-85°; the wind outlet angle is the angle β2 between the blade and the circumferential direction when leaving the blade, and the range of the wind outlet angle is 160°-175°.

8. A single suction centrifugal impeller, suitable for the unidirectional twisted blades as claimed in any one of claims 1 to 7, characterized in that: The centrifugal impeller includes a main shaft, an air outlet fixed wheel end and a bottom fixed wheel disc; an installation area is formed between the air outlet fixed wheel end and the bottom fixed wheel disc, and the main shaft is arranged on the outside of the bottom fixed wheel disc, and a rotation axis is arranged at the axis center of the main shaft, and a plurality of blades are evenly spaced and arranged in the installation area along the rotation axis, and the two ends of the blades are respectively connected to the opposite sides of the air outlet fixed wheel end and the bottom fixed wheel disc, wherein the length of the blade is parallel to the rotation axis, and the leading edge of the blade is closer to the rotation axis than the trailing edge thereof.

9. A centrifugal fan, suitable for the centrifugal impeller as claimed in claim 8, characterized in that: The centrifugal fan includes a driving motor, a volute body and a volute bracket; the output end of the driving motor is connected to the main shaft, the volute body is provided with a mounting cavity, a centrifugal impeller is arranged in the mounting cavity, the volute body is also provided with an air outlet, and a volute bracket is arranged at the lower end of the volute body.

10. A centrifugal fan according to claim 9, characterized in that: The volute is provided with an air collector cooperating with the centrifugal impeller, and the air collector is tightly connected with a sealing baffle, a bearing is provided at one end of the main shaft away from the drive motor, a volute tongue is also provided on the volute body, and a support frame is provided at the lower end of the drive motor.

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