A blade, an impeller assembly, and a centrifugal fan

Abstract

This utility model discloses a blade, an impeller assembly, and a centrifugal fan. The blade includes a blade body with a first end and a second end at two points in a first direction. The first end has a first end face, and the second end has a second end face. A plane parallel to the first and second end faces is defined as the cutting plane. The blade body includes a first guide surface and a second guide surface that are arranged opposite to each other. The cutting plane cuts through the first guide surface to obtain a first guide line, which includes a first arc segment and a straight segment that are connected to each other. The cutting plane cuts through the second guide surface to obtain a second guide line, which includes at least two arc segments with different radii of curvature. The blade of this utility model, through the combination of straight and arc segments of the first guide line and the synergy of multiple arc segments with different radii of curvature in the second guide line, can precisely control the airflow, effectively suppressing airflow separation, reducing eddy current generation, and lowering energy loss.

Description

Technical Field

[0001] This utility model belongs to the field of wind turbine technology, specifically relating to a blade, impeller assembly, and centrifugal fan. Background Technology

[0002] Currently, the guide surface of traditional centrifugal fan blades typically adopts a single-curvature arc segment design. From a fluid dynamics perspective, this design has significant limitations. During centrifugal fan operation, the velocity and pressure distribution of the airflow continuously changes as it moves along the blade guide surface. A single-curvature guide surface cannot balance the velocity differences of airflow in different parts of the blade, and cannot accurately match the velocity and pressure distribution of airflow in different areas.

[0003] For example, when airflow passes through the blades, in the blade inlet area, because the single curvature guide surface cannot provide an ideal guiding angle for the airflow, when the airflow enters the channel between the blades, the angle between it and the guide surface is often too large or too small, and the impact angle is unreasonable, which causes the airflow to be unable to adhere smoothly to the guide surface, resulting in impact loss and increased energy consumption.

[0004] In the blade exit region, the airflow needs to undergo a significant angle of deflection to exit the fan. A single-curvature guide surface with only a uniform curvature change at the exit cannot smoothly guide the airflow during deflection. The airflow separates due to the abrupt change in curvature during deflection, resulting in wake loss. The turbulent airflow within the wake region forms strong vortices, which not only increase airflow resistance but also significantly reduce the fan's aerodynamic efficiency. Simultaneously, the vortices generated by airflow separation induce airflow pulsations. These pulsating airflows periodically impact the blades and other fan components, generating high-frequency noise. Utility Model Content

[0005] One of the purposes of this invention is to disclose a blade that, through the combination of straight and curved segments of the first guide line and the synergy of multiple curved segments with different radii of curvature in the second guide line, can finely control the airflow, effectively suppress airflow separation, reduce eddy current generation, and thus reduce energy loss.

[0006] The second objective of this invention is to disclose an impeller assembly whose blade structure effectively suppresses airflow separation, significantly reduces the generation of eddies, and fundamentally reduces energy loss caused by airflow turbulence.

[0007] The third objective of this invention is to disclose a centrifugal fan whose impeller assembly, during airflow guidance, effectively suppresses airflow separation through its blade structure, significantly reducing the generation of eddies and fundamentally reducing energy loss caused by airflow turbulence. Due to the effective suppression of airflow separation and eddies by the blade structure, the vibration of the impeller assembly caused by airflow instability during operation is greatly reduced, thus significantly lowering the fan's noise.

[0008] To achieve one of the above objectives, this utility model discloses a blade, including a blade body, wherein the blade body has a first end and a second end at two ends in a first direction, the first end has a first end face, the second end has a second end face, and a plane parallel to the first end face and the second end face is defined as the cutting plane. The blade body includes a first air guide surface and a second air guide surface that are arranged opposite to each other. The cutting plane cuts through the first air guide surface to obtain a first air guide line, which includes a first arc segment and a straight segment that are connected to each other. The cutting plane cuts through the second air guide surface to obtain a second air guide line, which includes at least two arc segments and the at least two arc segments have different radii of curvature.

[0009] As an optional implementation, the connection point between the first arc segment and the straight line segment is defined as point A, and the tangent L1 of the first arc segment at point A coincides with the straight line containing the straight line segment.

[0010] As an optional implementation, the blade body includes a first segment and a second segment that are connected to each other. One side of the first segment is provided with a planar segment, and one side of the second segment is provided with a first arc-shaped segment. The first arc-shaped segment and the planar segment are connected to form the first air guide surface. The cutting plane cuts the planar segment to obtain the straight segment, and the cutting plane cuts the first arc-shaped segment to obtain the first arc segment.

[0011] As an optional implementation, the radius of curvature of the first arc segment obtained by each of the intercepting planes intercepting the first arc segment is the same along the first direction.

[0012] As an optional implementation, the direction of the line segment is defined as the second direction, and the width of the first segment gradually decreases along the second direction.

[0013] As an optional implementation, the second air guide surface includes three arc segments, which are a second arc segment, a third arc segment, and a fourth arc segment connected in sequence. The cutting plane cuts the second arc segment to obtain a second arc segment, the cutting plane cuts the third arc segment to obtain a third arc segment, and the cutting plane cuts the fourth arc segment to obtain a fourth arc segment. The radius of curvature of the second arc segment is smaller than that of the third arc segment, and the radius of curvature of the third arc segment is larger than that of the fourth arc segment.

[0014] As an optional implementation, along the first direction, the radii of curvature of the second arc segments obtained by the cutting plane from the second arc segment are all the same; the radii of curvature of the third arc segments obtained by the cutting plane from the third arc segment are all the same; and the radii of curvature of the fourth arc segments obtained by the cutting plane from the fourth arc segment are all the same.

[0015] As an optional implementation, the inlet angle of the blade body is α, and the value of α is in the range of 25° < α < 49°; the outlet angle of the blade body is β, and the value of β is in the range of 90° < β < 140°.

[0016] As an optional implementation, along the first direction, the entrance angle α on each intercepting plane gradually decreases, and the exit angle β gradually increases.

[0017] To achieve the second objective mentioned above, this utility model discloses an impeller assembly, including a mounting disk and a plurality of blades as described above. The mounting disk has a central axis and a mounting surface. The plurality of blade bodies are arranged at equal intervals around the central axis in a circumferential direction and are mounted on the mounting surface through the first end.

[0018] To achieve the third objective mentioned above, this utility model discloses a centrifugal fan, including a volute and an impeller assembly as described above, wherein the impeller assembly is mounted on the volute.

[0019] As an optional implementation, the centrifugal fan further includes an air guide component. The volute has an installation port, an air outlet, and an air cavity. The air guide component is installed in the installation port, and the impeller assembly is installed in the air cavity. The air guide component and the impeller assembly are coaxially arranged. The air guide component has an air guide channel that communicates with the air cavity and guides the airflow into the air cavity. The air outlet communicates with the air cavity and guides the airflow out of the air cavity. The air guide component has a blocking section on the side facing the impeller assembly. The blocking section is spaced apart from the second end of the blade body and forms a leakage prevention channel.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. The blade of this utility model can finely control the airflow by setting straight and arc segments on the first guide line of the blade body and multiple arc segments with different radii of curvature on the second guide line. This can effectively suppress airflow separation, reduce eddy current generation, and thus reduce energy loss.

[0021] 2. The impeller assembly of this invention effectively suppresses airflow separation through its blade structure, significantly reducing the generation of eddies and fundamentally reducing energy loss caused by airflow turbulence. Due to the effective suppression of airflow separation and eddies by the blade structure, the vibration of the impeller assembly caused by airflow instability is greatly reduced during operation.

[0022] 3. The centrifugal fan of this invention, through its blade structure, effectively suppresses airflow separation during airflow guidance, significantly reducing the generation of eddies and fundamentally reducing energy loss caused by airflow turbulence. Due to the effective suppression of airflow separation and eddies by the blade structure, the vibration of the impeller assembly caused by airflow instability during operation is greatly reduced, significantly lowering the fan's noise. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the blade body cut by multiple cutting planes in Embodiment 1 of this utility model; Figure 2 This is a schematic diagram of the blade body of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the structure of the blade body in Embodiment 1 of this utility model, in which the first end is cut off by a plane. Figure 4 This is a schematic diagram of the structure of the blade body in Embodiment 1 of this utility model, in which the second end is cut off by a plane. Figure 5 This is a schematic diagram of the impeller assembly according to Embodiment 2 of this utility model; Figure 6 This is a front view of the impeller assembly according to Embodiment 2 of this utility model; Figure 7 This is a schematic diagram of the inlet angle and outlet angle of the blade body at the first end face of Embodiment 1 and Embodiment 2 of this utility model; Figure 8 This is a schematic diagram of the inlet angle and outlet angle of the blade body at the second end face of Embodiment 1 and Embodiment 2 of this utility model; Figure 9 This is a schematic diagram of the centrifugal fan components when disassembled according to Embodiment 3 of this utility model; Figure 10 This is a cross-sectional schematic diagram of the assembled components of the centrifugal fan according to Embodiment 3 of this utility model; Figure 11 This is a schematic diagram showing the internal airflow direction of the centrifugal fan during operation according to Embodiment 3 of this utility model; Figure 12 This is a side view of the air guide component according to Embodiment 3 of this utility model; Figure 13 This is a cross-sectional schematic diagram of the assembled components of a centrifugal fan in the prior art.

[0025] Explanation of key figure labels: 10. Blade body; 101. First end face; 102. Second end face; 103. Cut plane; 11. First guide surface; 111. First arc segment; 112. Planar segment; 12. Second guide surface; 121. Second arc segment; 122. Third arc segment; 13. First guide line; 131. First arc segment; 132. Straight segment; 14. Second guide line; 141. Second arc segment; 142. Third arc segment; 143. Fourth arc segment; 144. Fifth arc segment; 15. Leading edge transition surface; 151. Leading edge arc; 16. Trailing edge Transition surface; 161, trailing edge arc; 17, centerline; 20, impeller assembly; 21, mounting plate; 211, mounting surface; 22, diffuser channel; 23, hub; 30, volute; 31, mounting port; 32, air outlet; 33, air cavity; 331, annular cavity section; 34, first side plate; 35, second side plate; 36, enclosure plate; 40, air guide; 41, blocking section; 411, leakage prevention channel; 42, air guide channel; 43, air guide ring; 44, mounting section; 45, arc-shaped transition section; 50, drive motor; 51, drive shaft; 511, connecting end. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0028] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0029] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0030] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0031] The technical solution of this utility model will be further described below with reference to the embodiments and accompanying drawings.

[0032] Example 1 Please see Figure 1 and Figure 2 As shown, this application embodiment provides a blade, including a blade body 10, and the blade body 10 has a first end and a second end at two ends in a first direction, the first end having a first end face 101 and the second end having a second end face 102, and a plane parallel to the first end face 101 and the second end face 102 is defined as the cutting plane 103.

[0033] Specifically, the blade body 10 includes a first guide surface 11 and a second guide surface 12 arranged opposite to each other, see reference. Figure 3 or Figure 4 A first air guide line 13 can be obtained by cutting the first air guide surface 11 with a cutting plane 103, and the first air guide line 13 includes a first arc segment 131 and a straight line segment 132 that are connected to each other. At the same time, a second air guide line 14 can be obtained by cutting the second air guide surface 12 with the cutting plane 103, wherein the second air guide line 14 includes at least two arc segments, and the radii of curvature of the at least two arc segments are different.

[0034] It should be noted that, in this application, the first direction refers to the height direction of the blade. The first guide surface 11 and the second guide surface 12 are the two sides of the blade body 10 in the thickness direction.

[0035] Based on this structure, when the blades of this invention are used to perform work and guide the airflow, the airflow enters the diffuser channel 22 from the inlet end of the diffuser channel 22 formed between the two blades. Within the diffuser channel 22, the airflow is pressurized by the combined action of the first guide surface 11 of the blades and the second guide surface 12 of the adjacent blades. Simultaneously, the airflow is guided by the two guide surfaces and exits from the outlet end of the diffuser channel 22. Specifically, the airflow process at a certain blade height will be described below using the guidance process of the first guide line 13 and the second guide line 14.

[0036] When airflow enters the inlet of the diffuser channel 22, the airflow direction at the inlet often exhibits a significant directional deviation, resulting in a turbulent state. Part of the airflow first contacts the straight section 132 of the first guide line 13 near the inlet. This straight section 132, with its straight trajectory, quickly straightens the turbulent airflow direction at the inlet, allowing the airflow to enter the diffuser channel 22 in a stable and orderly manner. This effectively avoids localized high-speed impacts caused by the initial chaotic direction of the airflow, reduces the degree of turbulence upon entry, and thus minimizes energy loss caused by initial airflow turbulence.

[0037] When the airflow flows along the straight segment 132 to the first arc segment 131 of the first guide line 13, the curvature of the first arc segment 131 matches the airflow direction guided by the straight segment 132, thus smoothly receiving the airflow. When the airflow comes into contact with the first arc segment 131, the arc trajectory of the arc segment will exert a continuous force on the airflow, causing the airflow to change its flow direction under the continuous force, realizing a gradual transition of airflow direction, reducing separation and turbulence caused by sudden changes in airflow direction, and guiding the airflow to flow smoothly along its arc within the diffuser channel 22.

[0038] Simultaneously, some of the airflow at the inlet end will also come into contact with the arc segment of the second guide line 14. The arc segment, using its curved trajectory, initially guides the airflow to change its direction, achieving initial rectification and guidance of the airflow at the inlet end. As the airflow moves forward within the diffuser channel 22, since the second guide line 14 is composed of at least two arc segments with different radii of curvature, it can be understood that the arc segment with smaller curvature can exert a stronger constraint and guiding force on the airflow through its compact curved trajectory, controlling the airflow trajectory and causing the airflow at the inlet end to accelerate and compress along a predetermined path within the diffuser channel 22. The arc segment with larger curvature can guide the airflow at a relatively gentle angle, allowing the airflow to gradually adjust its direction and speed within a relatively spacious area. This application uses arc segments with different radii of curvature to form the second guide line 14, enabling coordinated regulation of airflow speed and pressure.

[0039] More specifically, this embodiment takes the second air guide 14 as an example, which includes two arc segments. The two arc segments are the second arc segment 141 and the third arc segment 142. The radius of curvature of the second arc segment 141 is smaller than the radius of curvature of the third arc segment 142, and the second arc segment 141 is located at the air inlet end of the blade.

[0040] It should be noted that the geometric characteristics of arc segments with larger radii of curvature (such as the third arc segment 142) are that the curve curvature is gentler. If used alone for the entire guide line, in order to meet the profile length required for airflow guidance, the blade solid structure needs to extend more radially, which leads to an increase in the radial length of the blade.

[0041] The curve of the arc segment with a smaller radius of curvature (such as the second arc segment 141) is steeper. The profile length required to guide the airflow to change the same angle is shorter than that of the profile with a larger radius of curvature. If used alone for the entire guide line, although it can reduce the blade width, the steeper curve can easily cause the airflow velocity to change drastically during the flow. The airflow in the boundary layer cannot continue to flow along the blade surface, which will cause separation and form a large number of vortices.

[0042] Therefore, this application employs a small radius of curvature arc segment (second arc segment 141) at the air inlet, which can quickly change the airflow direction and reduce the radial extension requirement; while a large radius of curvature arc segment (third arc segment 142) is used at the air outlet. Although a certain radial length is required, the large radius of curvature arc segment ensures smooth airflow exit since the airflow has already undergone major deflection. By combining arc segments with various radii of curvature, the increase in the overall radial length of the blade caused by using a large radius of curvature throughout the entire process is avoided, and airflow separation losses are also reduced.

[0043] Therefore, through the coordinated action of the first guide surface 11 and the second guide surface 12, airflow separation can be effectively suppressed, and the generation of eddies and pulsations can be reduced. When the blades of this application are applied to a wind turbine, the operating noise of the wind turbine can be reduced. At the same time, by reducing airflow energy loss, the aerodynamic efficiency of the wind turbine can be improved, and the energy consumption per unit air volume can be reduced.

[0044] As an optional implementation method, see [link / reference]. Figure 3 Let point A be the connection point between the first arc segment 131 and the straight line segment 132, and let the tangent L1 of the first arc segment 131 at point A coincide with the straight line containing the straight line segment 132.

[0045] Thus, when the airflow enters from the inlet of the diffuser channel 22, it first comes into contact with the straight section 132 of the first guide line 13. The straight section 132, with its straight trajectory, initially regulates the turbulent airflow, allowing it to flow towards point A in a relatively stable state. Since the tangent L1 of the first arc section 131 at point A coincides with the straight line of the straight section 132, this means that when the airflow reaches point A, its flow direction is the same as that of the first arc section 131 at point A. This allows the airflow to transition naturally and smoothly from the straight section 132 to the first arc section 131 without changing its own motion trend. It should be noted that if there is an angle difference at the junction of the straight segment 132 and the first arc segment 131, the airflow will generate a large impact and turbulence due to the sudden change in direction when passing through this position, which will lead to increased energy loss and may even cause airflow separation.

[0046] Therefore, by aligning the tangent L1 of the first arc segment 131 at point A with the straight line containing the straight line segment 132, this application effectively avoids abrupt changes in airflow direction during the transition from the straight line segment 132 to the first arc segment 131. Subsequently, the airflow can smoothly continue to flow along the curved trajectory of the first arc segment 131. The first arc segment 131, using its curved trajectory, applies a continuous force to the airflow, guiding it to change direction smoothly without losing excessive kinetic energy, and allowing it to continue moving stably within the diffuser channel 22. Furthermore, it ensures the stability and reliability of the blades during the work and guidance of airflow. Under actual operating conditions, parameters such as airflow velocity and pressure will constantly change. By connecting the straight segment 132 and the first arc segment 131 at the same angle, the blades can always efficiently guide airflow under various complex airflow conditions, reducing the additional force on the blades caused by airflow fluctuations and extending the service life of the blades.

[0047] As an optional implementation, the blade body 10 includes a first segment and a second segment that are connected to each other. Specifically, one side of the first segment has a planar segment 112, and one side of the second segment has a first arcuate segment 111. The first arcuate segment 111 connects with the planar segment 112 to form the first air guide surface 11. The planar segment 112 is cut off using a cutting plane 103 to obtain the straight segment 132, and the first arcuate segment 111 is cut off using the cutting plane 103 to obtain the first arcuate segment 131.

[0048] Based on this structure, when the airflow enters from the air inlet of the diffuser channel 22, it first contacts the first flat section 112. The flat section 112 can generate friction and geometric constraints through its flat surface contact with the airflow, which initially regulates the chaotic airflow direction. Furthermore, its straight structure can effectively prevent the airflow from generating local high-speed impacts due to collisions, so that the airflow flows in a relatively stable and orderly manner toward the junction of the flat section 112 and the first arc section 111. As the airflow flows along the planar segment 112 to the junction with the first arcuate segment 111, the curvature of the first arcuate segment 111 is the same as the direction of the airflow emanating from the planar segment 112. When the airflow reaches the junction, the first arcuate segment 111, with its continuous curved surface, can seamlessly transition with the planar segment 112. The airflow does not need to drastically change its motion trend and can naturally continue to flow along the curved trajectory of the first arcuate segment 111. During this process, the curved structure of the first arcuate segment 111 exerts a continuous force on the airflow, guiding it to change direction smoothly without losing too much kinetic energy. This achieves a smooth turning of the airflow within the diffuser channel 22, effectively avoiding turbulence and separation caused by sudden changes in airflow direction, and reducing energy loss. Thus, the planar segment 112 of the first section and the first arc-shaped segment 111 of the second section work together. The planar segment 112 can perform preliminary airflow rectification, while the first arc-shaped segment 111 can perform fine-tuning of airflow guidance and direction adjustment. In actual working conditions, this segmented structure can continuously and stably guide airflow, reduce the additional stress caused by airflow fluctuations on the blades, and improve blade durability.

[0049] In addition, the first section on the side away from the planar section 112 and the second section on the side away from the first arc section 111 are each provided with at least one arc section, and these arc sections are connected in sequence to form the second air guide surface 12, with two adjacent arc sections connected at the same angle.

[0050] As an optional implementation, the first arc segment 131 obtained by each cutting plane 103 cutting the first arc segment 111 along the first direction has the same radius of curvature.

[0051] Based on this structure, when the airflow flows along the diffuser channel 22 in the first direction, the guiding force and flow constraint on the airflow in the cross section perpendicular to the blade height direction tend to be stable because the curvature radius of the first arc segment 131 at each height position is consistent.

[0052] After entering the diffuser channel 22, the airflow is initially regulated by the first planar section 112 and then enters the first arcuate section 111 of the second section. During its ascent or descent along the first direction, regardless of its height position on the blade, the first arcuate section 131 that the airflow contacts guides the airflow with the same curvature. This consistency ensures the continuity of the airflow trajectory along the height direction within the diffuser channel 22. For example, after the airflow smoothly changes direction along the first arcuate section 131 at a certain height, it will still change direction in the same way and to the same extent at higher or lower positions, without causing abrupt changes in airflow direction or generating additional disturbances due to height changes. Therefore, the first arc segment 131 with the same radius of curvature can effectively reduce the non-uniformity of airflow along the height direction within the diffuser channel 22. It should be noted that if the radius of curvature of the first arc segment 131 is different at different heights, the guiding force and flow resistance experienced by the airflow will change when passing through different heights, which may lead to local vortices or airflow separation within the diffuser channel 22.

[0053] This application maintains a consistent radius of curvature for the first arc segment 131 at all heights, ensuring that the airflow flows smoothly and evenly throughout the entire blade height range, which helps to improve the overall stability and smoothness of the airflow.

[0054] As an alternative implementation method, please refer again. Figure 2 Define the direction of the line containing line segment 132 as the second direction. (See also...) Figure 3 and Figure 4 ,in, Figure 3 To ensure that the cutting plane 103 coincides with the first end face 101, and the cutting plane 103 cuts the blade profile at the first end, Figure 4 The blade profile is obtained by aligning the cutting plane 103 with the second end face 102 and cutting the blade at the second end using the cutting plane 103. Along the first direction, the width of the first segment gradually decreases in the second direction.

[0055] Based on this structure, as the airflow enters the diffuser channel 22, it first comes into contact with the first planar section 112. Since the airflow at the inlet end is usually uneven in speed and turbulent in direction, the structure of the first section, whose width gradually decreases along the first direction and the second direction, can perform preliminary diversion and adjustment of the airflow. When the airflow rushes in from the inlet end, the wider blade root can catch more airflow. As the airflow flows along the first direction, the width of the first section gradually narrows, constraining the airflow in the width direction and promoting the gradual homogenization of the airflow velocity, avoiding situations where the local airflow velocity is too high or too low. During operation, as the airflow moves from the planar section 112 of the first segment to the first arcuate section 111 of the second segment, the gradually decreasing width of the second segment effectively reduces the risk of boundary layer separation on the blade surface. When airflow passes over an object's surface, the boundary layer is prone to separation at abrupt shape changes, generating eddies and increasing energy loss. The gradually narrowing width of the first segment provides a smooth transition space for the airflow, allowing it to better conform to the blade surface. The gradually narrowing width creates a pressure gradient related to the flow direction, which helps the airflow overcome surface friction, maintain boundary layer stability, reduce energy loss caused by boundary layer separation, and improve the flow efficiency within the diffuser channel 22. Furthermore, when multiple blades of this application are mounted on the impeller, the first end of the blade is mounted on the mounting plate 21 of the impeller, while the second end is cantilevered. This causes the second end of the blade to bear a large centrifugal force and vibration load during the high-speed rotation of the impeller. This application reduces the weight of the blade at the second end by gradually narrowing the width of the first section of the blade from the first end to the second end. When the impeller rotates at high speed, the originally heavy second end of the blade will generate a strong centrifugal pull, causing a large load on the blade root and the entire impeller structure. By reducing the weight of the second end, the centrifugal force is significantly reduced, effectively reducing the risk of blade deformation caused by centrifugal force, avoiding excessive stress on the blade root leading to fatigue damage or fracture, thereby enhancing the reliability and safety of the blade structure.

[0056] As an optional implementation method, see [link / reference]. Figure 3 The second air guide surface 12 includes three arcuate segments: a second arcuate segment 121, a third arcuate segment 122, and a fourth arcuate segment connected sequentially. The second arcuate segment 141 is obtained by cutting the second arcuate segment 121 with a cutting plane 103; the third arcuate segment 142 is obtained by cutting the third arcuate segment 122 with a cutting plane 103; and the fourth arcuate segment 143 is obtained by cutting the fourth arcuate segment with a cutting plane 103. Furthermore, the radius of curvature of the second arcuate segment 141 is smaller than that of the third arcuate segment 142, and the radius of curvature of the third arcuate segment 142 is larger than that of the fourth arcuate segment 143.

[0057] Based on this structure, when the airflow enters from the inlet of the diffuser channel 22, part of the airflow will first come into contact with the second arc segment 141 near the inlet. Since the airflow at the inlet typically has a high degree of turbulence and large velocity fluctuations, the small radius of curvature of the second arc segment 141 gives it a compact curved trajectory, which can exert a strong constraint and guiding force on the airflow, rapidly changing its initial direction and initially guiding the turbulent airflow into the interior of the diffuser channel 22. In other words, the small radius of curvature forces the airflow to accelerate when passing through this segment, which not only helps to disperse the vortices at the inlet but also allows the airflow to quickly obtain a relatively stable flow direction. As the airflow continues to move within the diffuser channel 22, it enters the region of influence of the third arc segment 142. The larger radius of curvature of the third arc segment 142 provides a relatively gentle curve trajectory and ample flow space. Here, the high velocity gained by the airflow in the second arc segment 141 is adjusted, and the force exerted on the airflow by the third arc segment 142, with its gentle curve, is relatively weakened, allowing the airflow to further adjust its direction and velocity in a relatively stable state. When the airflow reaches the fourth arc segment 143, its radius of curvature decreases again, allowing the fourth arc segment 143 to provide final precise guidance and acceleration of the airflow. At this point, the fourth arc segment 143, with its compact curved structure, exerts strong constraint on the airflow, causing it to accelerate along a predetermined path within the diffuser channel 22 and exit from the outlet of the diffuser channel 22 at a specific speed and direction.

[0058] Thus, the three arc segments of the second guide surface 12 work together: the second arc segment 141 rapidly rectifyes and initially accelerates the turbulent airflow at the inlet; the third arc segment 142 further adjusts the airflow speed and direction and balances the pressure; and the fourth arc segment 143 achieves precise airflow guidance and final acceleration. Through the difference in curvature radius, these three segments finely control the airflow speed, direction, and pressure at different stages, effectively suppressing airflow separation, reducing eddies and pulsations, and lowering the fan's operating noise. Simultaneously, this precise airflow guidance method minimizes airflow energy loss, significantly improves the fan's aerodynamic efficiency, and reduces energy consumption per unit air volume.

[0059] In addition, the second air guide surface 12 may also include four curved sections, see reference. Figure 4 Correspondingly, the second air guide line 14 includes four arc segments, namely the second arc segment 141, the third arc segment 142, the fourth arc segment 143, and the fifth arc segment 144. The radius of curvature of the third arc segment 142 is greater than that of the second arc segment 141, the radius of curvature of the fourth arc segment 143 is greater than that of the third arc segment 142, and the radius of curvature of the fifth arc segment 144 is less than that of the fourth arc segment 143.

[0060] Understandably, each arc segment can exert a force on the airflow in a specific direction and intensity based on its unique curvature. By setting more arc segments, the direction of the airflow can be gradually changed over a shorter distance and at a finer scale, avoiding significant energy loss and eddies caused by sudden changes in airflow direction. This enables more precise and complex control of the airflow, significantly improving the blade's guiding effect on the airflow.

[0061] As an optional implementation method, see [link / reference]. Figure 3 as well as Figure 4 Along the first direction, the radii of curvature of the second arc segment 141 obtained by cutting the second arc segment 121 from the plane 103 are all the same, the radii of curvature of the third arc segment 142 obtained by cutting the third arc segment 122 from the plane 103 are all the same, and the radii of curvature of the fourth arc segment 143 obtained by cutting the fourth arc segment from the plane 103 are all the same.

[0062] Based on this structure, when the airflow enters the diffuser channel 22 and contacts the second arc segment 121, since all the second arc segments 141 have the same radius of curvature, the guiding force and constraint degree experienced by the airflow are consistent in every cross-section perpendicular to the blade height direction. This ensures that the airflow does not experience abrupt changes in guiding force due to height changes when it rises or falls along the first direction. For example, at a certain height, after the airflow completes initial directional adjustment and acceleration through the second arc segment 141, it will continue to change direction and speed to the same extent and in the same way at higher or lower positions, ensuring that the airflow maintains a stable and continuous flow trajectory throughout the entire blade height range. This reduces airflow turbulence, separation, or vortex phenomena caused by uneven guidance, greatly improving the stability of the airflow. Similarly, when the airflow reaches the third arc segment 122 or the fourth arc segment, it can also maintain a stable and continuous flow trajectory at different heights.

[0063] Therefore, stable airflow guidance characteristics can effectively reduce fatigue damage to the blades. It should be noted that if the radius of curvature of the arc segments at different heights is different, the force exerted by the airflow on the blade surface will fluctuate with height, which can easily lead to fatigue cracks in the blades over long periods. However, by maintaining a consistent radius of curvature for each arc segment, the force distribution on the blade surface is more uniform, reducing localized stress concentration caused by uneven stress, lowering the risk of blade fatigue damage, and thus extending the blade's service life.

[0064] Furthermore, the tangent directions of the two interconnected arc segments are the same at the connection point, enabling a seamless transition of airflow. When airflow moves from one arc segment to another along the second guide line 14, the consistent tangent direction at the connection point allows the airflow to smoothly transition from one arc segment to the next without changing its motion trend. This effectively avoids airflow impact and turbulence caused by abrupt changes in direction, reducing the risk of airflow separation.

[0065] As an optional implementation, the inlet angle of the blade body 10 is α, and the value of α is in the range of 25° < α < 49°; at the same time, the outlet angle of the blade body 10 is β, and the value of β is in the range of 90° < β < 140°.

[0066] Specifically, the blade body 10 also includes a leading edge transition surface 15 and a trailing edge transition surface 16. The air inlet end of the first air guide surface 11 and the air inlet end of the second air guide surface 12 are connected by the leading edge transition surface 15, and the air outlet end of the first air guide surface 11 and the air outlet end of the second air guide surface 12 are connected by the trailing edge transition surface 16. Both the leading edge transition surface 15 and the trailing edge transition surface 16 are arc-shaped guiding surfaces.

[0067] When airflow enters from the inlet, the leading edge transition surface 15, with its smooth arc-shaped surface, effectively guides the airflow smoothly into the diffuser channel 22, avoiding strong impacts and eddies caused by sudden turns at the inlet. Compared to the planar leading edge transition surface 15, the arc-shaped guiding surface is less likely to form sharp corners at the inlet, reducing energy loss during airflow entry and allowing the airflow to contact the first guide surface 11 and the second guide surface 12 in a relatively orderly manner. After the airflow completes its flow within the diffuser channel 22, the arc-shaped structure of the trailing edge transition surface 16 ensures that the airflow can be smoothly discharged from the diffuser channel 22.

[0068] Specifically, the leading edge arc 151 is obtained by cutting the leading edge transition surface 15 with the cutting plane 103, and the trailing edge arc 161 is obtained by cutting the trailing edge transition surface 16 with the cutting plane 103. (See reference...) Figure 7 A centerline 17 is provided between the first guide line 13 and the second guide line 14. It should be noted that the centerline 17 is a curve; the centerline 17 divides the blade body 10 into two segments along the thickness direction. The connection point between the leading edge arc 151 and the centerline 17 is defined as point B, and the tangent of the centerline 17 at point B is L2. A circle is drawn with the rotation center of the mounting plate 21 as the center and the distance from point B to the rotation center of the mounting plate 21 as the radius. The tangent of this circle at point B is L3, and the angle between L2 and L3 is the blade inlet angle α.

[0069] Similarly, the connection point between the trailing edge arc 161 and the centerline 17 is defined as point C, and the tangent of the centerline 17 at point C is L4. A circle is drawn with the rotation center of the mounting plate 21 as the center and the distance from point C to the rotation center of the mounting plate 21 as the radius. The tangent of this circle at point C is L5, and the angle between L4 and L5 is the exit angle β of the blade.

[0070] If α is too small (≤25°), the angle between the airflow entry direction and the tangent of the blade centerline 17 is too steep, which easily forms a strong impact with the guide surface, generating vortices and energy loss; if α is too large (≥49°), the airflow is prone to boundary layer separation on both sides of the blade body 1, causing airflow separation loss. Therefore, when the blade inlet angle α is set between 25° and 49°, the arc-shaped transition surface of the blade leading edge matches the inlet angle, which can guide the airflow smoothly into the diffuser channel 22, reduce impact loss, and improve intake efficiency.

[0071] If β ≤ 90°, the blades are backward-curved, resulting in a smaller circumferential component of the absolute velocity at the air outlet. This leads to decreased pressure conversion efficiency and lower total pressure, making it difficult to meet high-pressure requirements. If β ≥ 140°, the blades are excessively forward-curved. In this case, the width of the diffuser channel 22 decreases at the outlet. The diffuser channel 22 as a whole has a smaller inlet width, gradually increasing width, and then decreasing again. This causes the relative velocity of the airflow to first decrease and then increase, easily leading to separation losses and reduced impeller efficiency. Therefore, when the blade outlet angle β is set between 90° and 140°, the circumferential component of the absolute velocity at the outlet is smaller, while the radial component is larger. This allows the gradual expansion of the diffuser channel 22 to more effectively convert the kinetic energy of the airflow into pressure energy. The airflow can be discharged from the diffuser channel 22 at a suitable speed and direction, ensuring full utilization of the airflow's kinetic energy and avoiding airflow turbulence and energy loss caused by an unreasonable angle.

[0072] In addition, reasonable blade inlet and outlet angles can optimize the pressure distribution on the blade surface, reduce the impact of airflow on the blade trailing edge, reduce vibration and noise caused by uneven stress on the blade, extend the service life of the blade, and improve the stability and reliability of equipment operation.

[0073] Therefore, this embodiment, through the arc-shaped structure of the leading-edge transition surface 15 and the trailing-edge transition surface 16, and by limiting the blade inlet angle and the blade outlet angle within a certain range, optimizes the entire process from airflow entry to exit, reducing energy loss of airflow when entering and exiting the diffuser channel 22, and suppressing the generation of eddies and airflow separation phenomena. At the same time, stable airflow also reduces vibration and noise during equipment operation, reduces equipment maintenance costs, and enables the equipment to operate in a more efficient and stable state.

[0074] It should be added that after each cutting plane 103 cuts the entire blade, a cross-sectional profile is obtained, and the cross-sectional profile is formed by connecting the first guide line 13, the leading edge arc 151, the second guide line 14 and the trailing edge arc 161 end to end in sequence to form a closed profile.

[0075] As an optional implementation, along the first direction, the entrance angle α on each intercepting plane 103 gradually decreases, and the exit angle β gradually increases.

[0076] See Figure 7 The blade body 10 is located at the height of the first end face 101, with an inlet angle of α1 and an outlet angle of β1; see reference. Figure 8 At the height of the second end face 102, the blade body 10 has an inlet angle of α2 and an outlet angle of β2, where α1 is greater than α2 and β1 is less than β2, and this change is gradual in the first direction. For example, a cutting plane 103 can be set between the first end face 101 and the second end face 102, and the distance from the cutting plane 103 to both the first end face 101 and the second end face 102 is the same. Then the inlet angle on the cutting plane 103 is α3 and the outlet angle is β3. At this time, α1, α3, and α2 can gradually decrease with equal arithmetic angles, and similarly, β1, β3, and α2 can gradually increase with equal arithmetic angles, making the angle change more uniform and gradual.

[0077] As the airflow rises along the blade height, the inlet angle gradually decreases, providing a more suitable entry angle for the airflow at the blade inlet. Specifically, during its ascent, the airflow gradually adapts to the changes in circumferential velocity caused by the blade rotation. On the intercept plane 103 at different heights, it adjusts its entry posture according to the changes in the inlet angle, avoiding excessive impact or poor entry at a certain height due to a fixed inlet angle. For example, at lower positions, a larger inlet angle better matches the lower circumferential velocity, allowing the airflow to smoothly transition from axial to radial flow and reducing initial impact losses. At higher positions, appropriately reducing the inlet angle matches the significantly increased circumferential velocity, allowing the airflow to enter the diffuser channel 22 with a posture more closely aligned with the blade angle, avoiding vortices caused by velocity direction mismatch, and ensuring that the airflow maintains an orderly flow state during the entry phase.

[0078] As the airflow moves along the blade height, the exit angle gradually increases as the airflow rises, providing more space for the airflow to exit at the blade's outlet. During this upward movement, the airflow can gradually adjust its speed and direction, adapting its flow trend according to the changes in the exit angle on the intercept plane 103 at different heights. This avoids excessive constraint or dispersion of the airflow at a certain height due to a fixed exit angle. For example, at lower positions, a smaller exit angle allows the airflow to quickly straighten its direction and accelerate moderately; while at higher positions, appropriately increasing the exit angle enhances the blade's work capacity, allowing the airflow to exit more smoothly. It should be noted that traditional blades with fixed inlet and outlet angles may experience significant adverse pressure gradients or airflow diffusion losses at certain heights due to a mismatch between the inlet and outlet angles and the actual airflow requirements. This application, however, achieves this by gradually decreasing the inlet angle and gradually increasing the outlet angle, ensuring that the airflow at each height is adapted to the inlet and outlet angles. At lower blade positions, the smaller outlet angle, while constraining the airflow to some extent, helps to quickly streamline the airflow, and the energy loss is relatively small because the airflow velocity and energy are not yet fully developed. As the airflow ascends, the outlet angle increases, precisely adapting to the changes in airflow velocity and direction during the flow process. This reduces airflow deceleration and boundary layer separation caused by adverse pressure gradients, while also avoiding excessive airflow dispersion caused by an excessively large outlet angle.

[0079] In this way, the airflow can maintain a relatively stable energy state throughout the entire blade height range, converting more kinetic energy into the pressure energy required by the equipment, greatly improving the aerodynamic efficiency of the equipment and reducing the energy consumption per unit air volume. Furthermore, since the inlet angle α gradually decreases and the outlet angle β gradually increases on each cross-sectional plane 103 in the first direction, and the shape and angle of the first guide line 13 and the second guide line 14 differ on the cross-sectional plane 103 at different heights of the blade, when viewed from a three-dimensional perspective, these changes in cross-sectional shape at different heights cause the blade to appear as a twisted state. That is, the blade of this application is a three-dimensional twisted blade.

[0080] Example 2 See Figure 5 and Figure 6 This embodiment discloses an impeller assembly 20, which includes a mounting disk 21 and multiple blades of Embodiment 1. The mounting disk 21 has a central axis and a mounting surface 211. Multiple blade bodies 10 are arranged at equal intervals around the central axis in the circumferential direction and are mounted on the mounting surface 211 through a first end.

[0081] Based on this structure, when using the impeller assembly 20 of this utility model, during assembly, multiple blade bodies 10 are arranged at equal intervals around the central axis along the circumferential direction. In this application, the central axis of the mounting disk 21 extends along the first direction. The blades are mounted on the mounting surface 211 via a first end, and the first end and the mounting surface 211 can be fixed by welding, bolting, or mortise and tenon joints to ensure that the blades do not loosen during high-speed rotation.

[0082] Thus, the blades can be firmly attached to the mounting plate 21 and rotate at high speed under the drive of the mounting plate 21 to do work and guide the airflow; and the blades are evenly distributed, which can balance the forces during rotation.

[0083] Among them, see Figure 7 and Figure 8 The exit angle β of the blade body 10 at the height of the first end face 101 and the second end face 102 is greater than 90°, and the exit angle β of the blade body 10 at different heights between the first end face 101 and the second end face 102 is also greater than 90°. The outlet direction of the airflow is towards the rotation direction of the impeller assembly 20, and the blade is a forward-curved three-dimensional twisted blade.

[0084] It should be noted that the first air guide surface 11 in this application is the windward surface, and the second air guide surface 12 is the air intake surface.

[0085] When the impeller assembly 20 starts operating, turbulent external airflow rushes in from the inlet end of the diffuser channel 22 formed between the blades. Since the straight section 132 of the first guide surface 11 of the blades is close to the inlet end, the airflow first contacts this straight section 132. The straight section 132, with its straight trajectory, quickly straightens the airflow direction, allowing the airflow to enter the diffuser channel 22 in a stable state. Simultaneously, part of the airflow at the inlet end contacts the small-radius curved section of the second guide surface 12. This curved section, with its steep curvature, provides initial and rapid deflection guidance to the airflow. As the impeller continues to rotate, the airflow continues to flow within the diffuser channel 22. At this time, the arc-shaped section of the first guide surface 11 and the large-radius arc section of the second guide surface 12 come into play. The arc-shaped section of the first guide surface 11 smoothly connects with the straight section 132, and its curvature matches the airflow direction guided by the straight section 132, further guiding the airflow to change direction within the channel; the large-radius arc section of the second guide surface 12 uses its gentle curvature to adjust the speed and pressure of the airflow, preventing the airflow from separating due to excessive speed or sudden changes in direction. When the airflow reaches the outlet of the diffuser channel 22, because the blade outlet angle β is greater than 90°, the airflow not only has tangential velocity but also gains an additional radial velocity component when leaving the diffuser channel 22. During the rotation of the impeller assembly 20, the forward-curving blade outlet angle causes the airflow to deviate from the radial direction at a larger angle, enhancing the circumferential velocity of the airflow and significantly increasing the outlet pressure of the blade.

[0086] Finally, the arc-shaped structure of the blade trailing edge transition surface 16 and the specific blade exit angle ensure that the airflow can be discharged at a suitable speed and direction. Multiple blades are arranged at equal intervals around the central axis, and the mounting plate 21 drives the blades to rotate at high speed around the central axis, continuously drawing in external airflow and performing work, realizing efficient airflow processing and energy conversion, and finally delivering the processed airflow to the target location to meet the equipment's operating requirements.

[0087] The blades can perform work and guide the airflow within the diffuser channel 22. Their blade structure includes the combination of the planar section 112 and the first arcuate section 111 of the first guide surface 11, the synergy of multiple arcuate sections with different radii of curvature on the second guide surface 12, and the arcuate guide surface of the leading and trailing edge transition surface 16, providing precise control of the airflow from multiple dimensions. During airflow guidance, the blade structure effectively suppresses airflow separation, significantly reduces the generation of vortices, and fundamentally reduces energy loss caused by airflow turbulence. Due to the effective suppression of airflow separation and vortices by the blade structure, the vibration of the impeller assembly 20 caused by airflow instability is greatly reduced during operation.

[0088] The specific structural details of the blades and their guiding mechanism for airflow have been described in detail in Example 1, including the design principles of the curvature of each arc segment and the influence of the exit angle on airflow, etc., and will not be repeated here.

[0089] It should be noted that in this embodiment, the first end of the blade is mounted on the mounting plate 21, while the second end of the blade is far from the mounting plate 21 and in a cantilever state, eliminating the need for additional intermediate support structures to maintain the blade shape and stability. Compared to traditional blade structures with two or more supports, this application can reduce the amount of metal material required for support components, including connectors, support beams, and other parts, thereby reducing the overall weight of the impeller assembly 20. As a result, the moment of inertia of the impeller is reduced during operation, and the energy required to overcome inertia during acceleration, deceleration, and variable operating conditions is reduced. Therefore, the impeller assembly 20 can reach its rated speed from a stationary state more quickly, shortening the equipment start-up time and improving the equipment response efficiency.

[0090] Example 3 See Figure 9 and Figure 10This embodiment discloses a centrifugal fan, which includes a volute 30 and an impeller assembly 20 as described in Embodiment 2 above. The impeller assembly 20 is mounted on the volute 30.

[0091] Based on this structure, when using the centrifugal fan of this application, after the centrifugal fan is started, external gas enters the fan through the pre-set air inlet on the volute 30. At this time, the impeller assembly 20 rotates at high speed under the drive of the motor, and a negative pressure area is formed inside the volute 30 at the air inlet, and the external gas is drawn in under the action of the pressure difference. The gas entering the fan first comes into contact with the high-speed rotating impeller assembly 20. The blades in the impeller assembly 20 are arranged at equal intervals around the central axis, and the first end of the blade is fixed to the mounting plate 21, and the second end is cantilevered. During the rotation of the impeller, the gas flows along the channel formed by the first guide surface 11 and the second guide surface 12 of the blades. The unique structure of the blades, such as the combination of the straight segment 132 and the arc segment of the first guide line 13, the synergy of multiple arc segments with different radii of curvature of the second guide line 14, and the specific blade outlet angle design, performs work and guides the gas. During airflow guidance, the straight section 132 at the inlet quickly regulates the turbulent airflow, while the arc section with a small radius of curvature initially redirects the airflow. The combination of arc sections with different radii of curvature within the channel makes the airflow velocity and pressure distribution more rational, preventing separation caused by sudden changes in direction or velocity. The trailing edge arc 161 at the outlet and the specific blade exit angle ensure that the airflow is discharged in a stable state. As the blades continue to rotate, the gas, under the action of centrifugal force, is thrown from the impeller center to the impeller edge, gaining kinetic energy. The accelerated gas enters the annular cavity section 331 between the volute 30 and the impeller assembly 20. Due to the restriction of the volute 30, the gas flow space gradually expands. According to Bernoulli's principle, the gas velocity decreases and the pressure increases, achieving a gas pressurization process. Finally, the pressurized gas is discharged from the outlet of the volute 30.

[0092] Therefore, during the airflow guidance process, the centrifugal fan effectively suppresses airflow separation through its blade structure, significantly reducing the generation of eddies and fundamentally reducing energy loss caused by airflow turbulence. Due to the effective suppression of airflow separation and eddies by the blade structure, the vibration of the impeller assembly 20 caused by airflow instability is greatly reduced during operation, significantly lowering the fan's noise.

[0093] As an optional implementation, the centrifugal fan further includes an air guide 40. The volute 30 has an installation port 31, an air outlet 32, and an air cavity 33. Specifically, the air guide 40 is installed in the installation port 31, and the impeller assembly 20 is installed in the air cavity 33, with the air guide 40 and impeller assembly 20 coaxially arranged. The air guide 40 has an air guide channel 42, which communicates with the air cavity 33 and guides airflow into the air cavity 33. The air outlet 32 ​​communicates with the air cavity 33 and guides the airflow out of the air cavity 33. (See reference...) Figure 10 and Figure 12 The air guide 40 has a blocking section 41 on the side facing the impeller assembly 20, and the blocking section 41 is spaced apart from the second end of the blade body 10 to form a leakage prevention channel 411.

[0094] Based on this structure, when the centrifugal fan starts running, the external airflow first reaches the mounting port 31 of the volute 30 and enters the air guide channel 42 of the air guide component 40. The shape and angle of the air guide channel 42 can initially sort and guide the turbulent initial airflow, so that the airflow flows towards the air cavity 33 in a relatively stable and orderly state. Since the air guide component 40 is coaxially set with the impeller assembly 20, the airflow adjusted by the air guide channel 42 can be accurately aligned with the air inlet area of ​​the impeller assembly 20 and smoothly enter the air cavity 33. The airflow entering the air chamber 33 encounters the high-speed rotating impeller assembly 20, is accelerated by the blades, and is thrown towards the impeller edge. Subsequently, the airflow undergoes a diffusion process in the annular cavity section 331 between the volute 30 and the impeller assembly 20. As the airflow flows from the impeller assembly 20 to the outlet 32, the anti-leakage channel 41 formed by the blocking section 41 of the guide vane 40 facing the impeller assembly 20 and the second end of the blade body 10 begins to function. This anti-leakage channel 411 restricts the return path of the airflow, ensuring that the airflow can only be discharged from the outlet 32 ​​in a predetermined direction, avoiding disordered flow of airflow inside the fan. Finally, the diffused and guided airflow is discharged from the outlet 32 ​​and delivered to the target location, completing the entire gas delivery process.

[0095] Among them, see Figure 13 In the centrifugal fan shown in the related technology, the air guide 40 and the impeller assembly 20 are axially spaced and form an installation gap. The first and second ends of the blades in the impeller assembly 20 are respectively connected to the first and second end mounting plates. As the fan starts and the impeller assembly 20 rotates, region a formed by the air guide channel 42 in the air guide 40 is under negative pressure and has the minimum pressure value, continuously drawing in external air. Region b is formed between the two blades and between the first and second end mounting plates. When the impeller assembly 20 rotates at high speed, the blades exert centrifugal force on the gas in region b, making region b a positive pressure. The annular region between the volute 30 and the impeller assembly 20 is region c. During the gas flow from region b to region c, because the spatial structure of region c is relatively wider than that of region b, the flow space suddenly increases after the gas enters region c. According to the principles of fluid mechanics, when the gas velocity decreases, its kinetic energy is gradually converted into pressure energy. Region c is a positive pressure and has the maximum pressure value.

[0096] Due to the directional flow of airflow, the pressure at one end of the radial end of the installation gap formed between the air guide 40 and the impeller assembly 20 in the axial direction is close to the pressure value of region a, and the pressure at the other end is close to the pressure value of region c. That is, there is a large pressure difference between the two ends. At this time, the airflow will flow from the high pressure end to the low pressure end. In other words, the airflow in region c will leak back through the gap. Furthermore, the excessive pressure difference between region a and region c results in a large flow velocity of the leaking airflow. The leaking airflow is perpendicular to the direction of the main airflow in region a, which seriously interferes with the flow of the main airflow and affects the air intake state and working efficiency of the impeller.

[0097] See Figure 9 and Figure 10 This application addresses the issue by providing a blocking section 41 at the axial end of the air guide 40, where the blade is mounted on the mounting plate 21 only from the first end of the blade body 10, and the second end of the blade body 10 and the blocking section 41 of the air guide 40 are axially spaced to form a leakage prevention channel 411. (See reference...) Figure 11 At this time, the air guide channel 42 inside the air guide component 40 is still under negative pressure, the area b formed between the two blades and the mounting plate 21 is under positive pressure, and the area c formed between the volute 30 and the impeller assembly 20 is under positive pressure with the highest pressure value. It is particularly important to note that since no second end mounting plate is provided between area b and the leakage channel 411, area b and the leakage channel 411 can be connected.

[0098] At this point, the pressure at one end of the radial ends of the anti-leakage channel 411 is close to the pressure in region b, and the pressure at the other end is close to the pressure in region c. Since both regions b and c are under positive pressure and there is a small pressure difference between them, the pressure difference between the two radial ends of the anti-leakage channel 411 is small, which reduces the amount of air flowing back from the gap. Simultaneously, because the leakage of the airflow is extremely small and the flow velocity is opposite to the direction of the main airflow, the leakage at the gap is further reduced under the influence of the main airflow.

[0099] Therefore, this application effectively prevents airflow from flowing back through the gap between the impeller assembly 20 and the guide vane 40, ensuring that the main airflow enters the impeller stably and evenly, reducing the degree of airflow turbulence inside the fan, and maintaining the stable rotation of the impeller. At the same time, the blocking section 41 can block the airflow between the blades at the second end, allowing more gas to remain between the blades to do work fully, and then enter the annular cavity section 331.

[0100] It should be noted that, in this embodiment, the centrifugal fan effectively suppresses airflow separation and significantly reduces vortex generation during airflow guidance through its blade structure. Furthermore, by optimizing the structure and installation of the air guide 40 and blade assembly, the flow interference of airflow recirculation within the air cavity 33 on the main airflow is reduced. This significantly improves the fan's aerodynamic efficiency, reduces energy loss, enhances operational stability, and reduces vibration and noise.

[0101] As an optional implementation, the volute 30 includes a first side plate 34, a second side plate 35, and a surrounding plate 36. Specifically, the first side plate 34 and the second side plate 35 are arranged opposite to each other, and the surrounding plate 36 is disposed between the first side plate 34 and the second side plate 35. The first side plate 34, the second side plate 35, and the surrounding plate 36 together form an air cavity 33. An installation port 31 is disposed on the first side plate 34, and an air outlet 32 ​​is disposed on the surrounding plate 36. The second side plate 35 has a through-hole. The centrifugal fan also includes a drive assembly, which includes a drive shaft 51. The drive shaft 51 passes through the through-hole and is connected to the mounting plate 21. The drive assembly is used to drive the mounting plate 21 to rotate.

[0102] Based on this structure, during assembly, the drive shaft 51 is equipped with a connecting end 511, and the mounting plate 21 is equipped with a hub 23. The connecting end 511 is fixedly connected to the hub 23. For details, please refer to [link / reference needed]. Figure 10 The hub 23 includes a mounting groove with a mounting hole at its axial end and a protrusion on one radial side. The outer periphery of the connecting end 511 has a groove, which is inserted into the mounting groove. The protrusion in the mounting groove is connected to the groove on the connecting end 511, restricting the circumferential disengagement of the drive shaft 51 from the mounting plate 21. The axial end face of the connecting end 511 also has a mounting hole, which is connected to the mounting hole of the mounting groove by bolts, screws, or other fasteners, restricting the axial disengagement of the drive shaft 51 from the mounting plate 21.

[0103] When the centrifugal fan starts, the drive shaft 51 in the drive assembly begins to rotate under the power of a motor or other power source. After passing through the opening of the second side plate 35, the drive shaft 51 connects to the mounting plate 21, thereby transmitting the rotational power to the mounting plate 21 and driving the impeller assembly 20 to rotate at high speed. The external airflow enters through the mounting port 31 located on the first side plate 34, and after being initially combed by the air guide channel 42 of the air guide 40, it enters the air cavity 33 formed by the first side plate 34, the second side plate 35, and the surrounding plate 36.

[0104] Within the air chamber 33, the airflow encounters the high-speed rotating impeller assembly 20. The blades exert centrifugal force on the airflow, causing it to move from the center of the impeller towards the edge, gaining kinetic energy. The accelerated airflow enters the annular cavity section 331 between the volute 30 and the impeller assembly 20 along the impeller edge. This annular cavity section 331 is formed by the surrounding plate 36 and the outer edge of the impeller. Due to the restriction of the surrounding plate 36, the airflow space gradually expands. According to Bernoulli's principle, the airflow velocity decreases and the pressure increases, achieving a gas pressurization process. Finally, the pressurized airflow is discharged from the outlet 32 ​​on the surrounding plate 36 and transported to the target location, completing the entire gas transport process. During the operation of the fan, the various components of the volute 30 work closely together to provide a stable operating environment for the impeller assembly 20, while effectively guiding and constraining the airflow.

[0105] The drive assembly also includes a drive motor 50, which is connected to the drive shaft 51 via direct drive, belt drive, or coupling drive.

[0106] Additionally, see Figure 12 The air guide component 40 also includes an air guide ring 43, a mounting section 44, and an arc-shaped transition section 45. The mounting section 44 and the blocking section 41 are positioned opposite each other and connected to the two ends of the air guide ring 43 along the axial direction. The mounting section 44 is also connected to the air guide ring 43 via the arc-shaped transition section 45. Both the mounting section 44 and the blocking section 41 are flanges extending radially from the ends of the air guide ring 43. The flange of the mounting section 44 is mounted to the mounting opening 31 of the first side plate 34 using fasteners such as screws and bolts. The inner circumferences of the air guide ring 43 and the arc-shaped transition section 45 form the air guide channel 42.

[0107] Thus, the installation section 44 securely fixes the air guide 40 to the first side plate 34 with tight bolt connections to prevent the air guide 40 from loosening or shifting; the arc transition section 45 guides the airflow gradually to the impeller assembly 20 through smooth arc changes, reducing the impact of airflow on the channel wall and reducing energy loss.

[0108] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A vane, characterized by: The blade body includes a blade body with a first end and a second end at two ends in a first direction. The first end has a first end face and the second end has a second end face. A plane parallel to the first end face and the second end face is defined as the cutting plane. The blade body includes a first air guide surface and a second air guide surface that are arranged opposite to each other. The cutting plane cuts through the first air guide surface to obtain a first air guide line, which includes a first arc segment and a straight segment that are connected to each other. The cutting plane cuts through the second air guide surface to obtain a second air guide line, which includes at least two arc segments and the at least two arc segments have different radii of curvature.

2. The blade according to claim 1, characterized in that: The connection point between the first arc segment and the straight line segment is defined as point A, and the tangent L1 of the first arc segment at point A coincides with the straight line containing the straight line segment.

3. The blade according to claim 1, characterized in that: The blade body includes a first segment and a second segment that are connected to each other. The first segment has a planar segment on one side, and the second segment has a first arc segment on one side. The first arc segment and the planar segment are connected to form the first air guide surface. The cutting plane cuts the planar segment to obtain the straight segment, and the cutting plane cuts the first arc segment to obtain the first arc segment.

4. The blade according to claim 3, characterized in that: Along the first direction, the radius of curvature of the first arc segment obtained by each of the cutting planes cutting the first arc segment is the same.

5. The blade according to claim 3, characterized in that: The direction of the line segment is defined as the second direction. Along the first direction, the width of the first segment gradually decreases in the second direction.

6. The blade according to claim 1, characterized in that: The second air guide surface includes three arc segments, which are a second arc segment, a third arc segment, and a fourth arc segment connected in sequence. The cutting plane cuts the second arc segment to obtain a second arc segment, the cutting plane cuts the third arc segment to obtain a third arc segment, and the cutting plane cuts the fourth arc segment to obtain a fourth arc segment. The radius of curvature of the second arc segment is smaller than that of the third arc segment, and the radius of curvature of the third arc segment is larger than that of the fourth arc segment.

7. The blade of claim 6, wherein: Along the first direction, the radii of curvature of the second arc segments obtained by the cutting plane from the second arc segment are all the same; the radii of curvature of the third arc segments obtained by the cutting plane from the third arc segment are all the same; the radii of curvature of the fourth arc segments obtained by the cutting plane from the fourth arc segment are all the same.

8. The blade of claim 1, wherein: The inlet angle of the blade body is α, and the value of α is in the range of 25° < α < 49°; the outlet angle of the blade body is β, and the value of β is in the range of 90° < β < 140°.

9. The blade of claim 8, wherein: Along the first direction, the entrance angle α on each intercepting plane gradually decreases, and the exit angle β gradually increases.

10. An impeller assembly characterized by: It includes a mounting plate and a plurality of blades as described in any one of claims 1-9, the mounting plate having a central axis and a mounting surface, the plurality of blade bodies being arranged at equal intervals around the central axis in a circumferential direction and mounted on the mounting surface through the first end.

11. A centrifugal fan, characterized in that: It includes a volute and an impeller assembly as described in claim 10, the impeller assembly being mounted on the volute.

12. The centrifugal fan of claim 11, wherein: The centrifugal fan further includes an air guide component. The volute has an installation port, an air outlet, and an air cavity. The air guide component is installed in the installation port, and the impeller assembly is installed in the air cavity. The air guide component and the impeller assembly are coaxially arranged. The air guide component has an air guide channel that communicates with the air cavity and guides the airflow into the air cavity. The air outlet communicates with the air cavity and guides the airflow out of the air cavity. The air guide component has a blocking section on the side facing the impeller assembly. The blocking section is spaced apart from the second end of the blade body and forms a leakage prevention channel.

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