An impeller structure, a multi-blade centrifugal fan and a multi-blade centrifugal blower

Abstract

This utility model relates to the field of multi-blade centrifugal fan technology, specifically to an impeller structure, a multi-blade centrifugal fan, and a multi-blade centrifugal blower. It includes a first disc and a second disc, and several blades located between them. The blades have an arc-shaped cross-section and are spirally twisted from the end closer to the first disc to the end closer to the second disc. A first centerline L1 exists at the end of the blade closer to the first disc, and a second centerline L2 exists at the end of the blade closer to the second disc. The projections of the first centerline L1 and the second centerline L2 intersect at an intersection point P. The intersection point P, the midpoint m1 of the first centerline L1, and the midpoint m2 of the second centerline L2 do not coincide simultaneously. This utility model optimizes the blade geometry, effectively improving the airflow guidance capability, improving airflow organization, and significantly reducing eddies and flow separation phenomena, thereby improving the aerodynamic performance of the blower. Furthermore, it improves the impeller's operating efficiency while effectively reducing operating noise.

Description

Technical Field

[0001] This utility model relates to the field of multi-blade centrifugal fan technology, specifically to an impeller structure, a multi-blade centrifugal fan, and a multi-blade centrifugal blower. Background Technology

[0002] The impeller is the main structure of a multi-blade centrifugal fan, as shown in the attached image. Figure 1 As shown, the impeller blades in existing multi-blade centrifugal fans mainly adopt a single circular arc straight blade structure. However, the existing straight blade structure has certain defects: (1) The angle is consistent in the entire impeller radius direction, which cannot match the different airflow directions in each section, resulting in the inflow angle deviation in different areas of the blade, forming an angle of attack loss, and ultimately reducing the efficiency of the fan; (2) When the airflow flows over the straight blade, separation and vortices are easily generated on the back of the blade. The vortex area not only reduces energy utilization, but also becomes a noise source, especially at high speeds; (3) The straight blade is prone to resonate with the airflow rhythm at a specific frequency, producing a noticeable "whistling sound". This is not conducive to the overall vibration control and noise control of the fan.

[0003] In summary, the currently used straight blade structure results in greater airflow impact during operation, which can easily lead to lower fan efficiency and higher operating noise. Utility Model Content

[0004] To address the technical problems of existing impeller blade defects, this utility model provides an impeller structure, a multi-blade centrifugal fan, and a multi-blade centrifugal blower. It optimizes the geometric structure of the blades, effectively improves the ability to guide airflow, improves airflow organization, and significantly reduces eddies and flow separation phenomena, thereby improving the aerodynamic performance of the blower. In addition, it also improves the impeller's operating efficiency and effectively reduces operating noise.

[0005] The technical solution provided by this utility model is as follows: an impeller structure, including a first disk and a second disk arranged opposite to each other, and a plurality of blades fixed in a uniform circumferential array between the first disk and the second disk. The cross-section of the blades is arc-shaped, and the blades are spirally twisted from the end closer to the first disk to the end closer to the second disk. A first center line L1 exists at the end of the blades closer to the first disk, and a second center line L2 exists at the end of the blades closer to the second disk. The projections of the first center line L1 and the second center line L2 intersect at an intersection point P. The intersection point P, the midpoint m1 of the first center line L1, and the midpoint m2 of the second center line L2 do not coincide simultaneously.

[0006] Optionally, the side of the blade closest to the center of its circumferential array is the air inlet side, which is inclined toward the convex side of the blade.

[0007] Optionally, the side of the blade away from the center of its circumferential array is the air outlet side, which is inclined toward the concave side of the blade.

[0008] Optionally, the inlet angle of the blade gradually increases from the end closer to the first disc to the end closer to the second disc.

[0009] Optionally, the blade has a root inlet angle α1 at the end near the first disc, where α1 satisfies 55.5°≤α1≤57.5°; and the blade has a top inlet angle α2 at the end near the second disc, where α2 satisfies 59°≤α1≤61°.

[0010] Optionally, the exit angle of the blade gradually increases from the end closer to the first disc to the end closer to the second disc.

[0011] Optionally, the blade has a root exit angle β1 at the end near the first disk, wherein β1 satisfies 159°≤β1≤161°; and the blade has a top exit angle β2 at the end near the second disk, wherein β2 satisfies 170°≤β2≤172°.

[0012] A multi-blade centrifugal fan includes the impeller structure described above, and also includes an impeller disk, wherein the first disk is fixedly connected to the impeller disk.

[0013] A multi-blade centrifugal fan, comprising the aforementioned multi-blade centrifugal fan.

[0014] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects: In view of the technical problems of defects in existing impeller blades, this utility model optimizes the geometric structure of the blades, effectively improves the ability to guide airflow, improves airflow organization, and significantly reduces eddies and flow separation phenomena, thereby improving the aerodynamic performance of the fan; in addition, it also improves the operating efficiency of the impeller and effectively reduces operating noise. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an existing impeller mentioned in the background section.

[0016] Figure 2 This is a schematic diagram of the impeller structure proposed in an embodiment of the present utility model.

[0017] Figure 3 This is a partial schematic diagram of the impeller structure proposed in an embodiment of the present invention.

[0018] Figure 4 This is a partial top view of the impeller structure proposed in an embodiment of the present invention.

[0019] Figure 5for Figure 4 Enlarged diagram of point A in the middle

[0020] Figure 6 This is a schematic diagram of the blade structure proposed in an embodiment of the present invention.

[0021] Figure 7 This is a projected schematic diagram of the blade proposed in an embodiment of the present invention.

[0022] Figure 8 This is a schematic diagram of the structure of the multi-blade centrifugal fan proposed in an embodiment of the present invention. Detailed Implementation

[0023] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0024] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the utility model. Furthermore, it should be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. The terms "first," "second," etc., used in this utility model are provided for the convenience of describing the technical solution of this utility model and have no specific limiting effect; they are all general terms and do not constitute a limitation on the technical solution of this utility model. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not contradict or conflict, all of which are within the scope of protection claimed by this utility model.

[0025] Example 1

[0026] Combined with appendix Figure 2 To be continued Figure 7 This embodiment proposes an impeller structure, including a first disk 1 and a second disk 2 arranged opposite to each other, and a plurality of blades 3 fixed in a uniform circumferential array between the first disk 1 and the second disk 2. The blades 3 have an arc-shaped cross-section and are spirally twisted from the end near the first disk 1 to the end near the second disk 2. Furthermore, a first centerline L1 exists at the end of the blade 3 near the first disk 1, and a second centerline L2 exists at the end of the blade 3 near the second disk 2. The projections of the first centerline L1 and the second centerline L2 along the blade's length direction intersect at an intersection point P. The intersection point P, the midpoint m1 of the first centerline L1, and the midpoint m2 of the second centerline L2 do not coincide simultaneously.

[0027] In this embodiment, the impeller structure has blades 3 that, compared to traditional straight blades 3, although the main cross-section is still arc-shaped, are helically twisted along their extension direction, such as... Figure 5 and Figure 7 As shown, when viewed along the axial direction (i.e., the length direction) of blade 3, the projections of the first centerline L1 and the second centerline L2 intersect at a single intersection point P, rather than being completely coincident.

[0028] Furthermore, the intersection point P, the midpoint m1 of the first center line L1, and the midpoint m2 of the second center line L2 do not coincide simultaneously, but the intersection point P may coincide with either the midpoint m1 or the midpoint m2.

[0029] As attached Figure 4 and attached Figure 5 As shown, the airflow flows from the inside to the outside of the impeller structure. Correspondingly, the blade 3 has an inlet edge 31 and an outlet edge 32. In this embodiment, the improvement to the blade 3 structure, from an overall perspective, involves the spiral twisting of the blade 3 and the design that the intersection point P, the midpoint m1 of the first centerline L1, and the midpoint m2 of the second centerline L2 do not coincide simultaneously. This causes the blade 3 to twist axially, resulting in the inlet edge 31 and the outlet edge 32 exhibiting opposite inclinations along the length of the blade 3. Furthermore, it allows the inclination degrees of the inlet edge 31 and the outlet edge 32 of the blade 3 to be different. For example, see attached... Figure 5 and attached Figure 7 Taking the example shown, the inlet edge 31 of blade 3 has a relatively small inclination, while the outlet edge 32 has a relatively large inclination. This difference in the inclination of the inlet edge 31 and the outlet edge 32 can better improve the aerodynamic conditions of blade 3.

[0030] In detail, ordinary blades generally only twist around their own central axis. That is, although the inclination direction of the airflow inlet side and the airflow outlet side of ordinary blades are opposite, the degree of inclination is generally the same.

[0031] In this embodiment, the blade 3 has a composite deformation that combines helical torsion and tilting. The position of the intersection point P is introduced as a parameter. Therefore, for real products, when designing the blade 3, those skilled in the art can further change the position of the intersection point P according to the actual situation and the degree of helical torsion, thereby changing the tilting degree of the air inlet side 31 and the air outlet side 32 of the blade 3 respectively, making the design of the axial deformation posture of the blade 3 more flexible.

[0032] It is important to note that since the direction of the spiral twist is fixed, the tilt directions of the inlet edge 31 and the outlet edge 32 are also fixed. Changing the position of the intersection point P requires consideration of the degree of spiral twist to affect the tilt degrees of the inlet edge 31 and the outlet edge 32 separately. If only the degree of spiral twist or only the position of the intersection point P is adjusted, the tilt degrees of the inlet edge 31 and the outlet edge 32 will only be adjusted synchronously. As a result, when the blade 3 has a structure combining spiral twist and tilt, and the tilt degrees of the inlet edge 31 and the outlet edge 32 are different, the aerodynamic angles of each section along the axial direction of the blade 3 can be effectively optimized. This guides the airflow to flow smoothly along the surface of the blade 3, effectively reducing airflow separation caused by angle mismatch, reducing energy loss, and improving aerodynamic efficiency.

[0033] Specifically, in this embodiment, the surface of blade 3 is a continuously spirally twisted curved surface. This design can coordinate the airflow velocity distribution at different radial positions, suppress local airflow pulsation and separation, reduce eddies and secondary flows, thereby effectively reducing overall operating noise and improving the aerodynamic performance and operational stability of the impeller. Furthermore, the spirally twisted curved surface can also reduce the natural frequency of blade 3, improve overall vibration resistance, effectively avoid resonance, and further enhance the operational reliability and extend the service life of the impeller structure.

[0034] In addition, due to the spatial curvature change formed on the surface of blade 3, a similar effect to a reinforcing rib is produced. Compared with straight blades, this significantly improves the structural strength of the sheet metal part itself, enhances its resistance to bending, deformation and fatigue, and thus improves the overall mechanical strength and durability of the impeller structure.

[0035] In the impeller structure, the side of the blade 3 closest to the center of its circumferential array is the air inlet edge 31. In a further embodiment, the air inlet edge 31 is inclined towards the convex side of the blade 3. In conjunction with the aforementioned first centerline L1 and second centerline L2, in this embodiment, it actually means that there is a misalignment between the end of the first centerline L1 located at the air inlet edge 31 and the end of the second centerline L2 located at the air inlet edge 31, so as to accommodate… Figure 4 and attached Figure 5 As shown in the view, this implementation makes the air inlet edge 31 of the blade 3 form a "backward tilt" structure.

[0036] This slightly "rearward-tilted" inlet edge 31 can guide the incoming flow at the inlet of blade 3, allowing the airflow to enter the impeller at a better incident angle, thereby reducing inlet impact loss, improving airflow adhesion, and enhancing overall flow stability.

[0037] In the impeller structure, the side of the blade 3 facing away from the center of its circumferential array is the outlet edge 32. In an embodiment similar to the aforementioned improvement, the outlet edge 32 is inclined towards the concave side of the blade 3. Similarly, in conjunction with the aforementioned first centerline L1 and second centerline L2, in this embodiment, it actually means that there is a misalignment between one end of the first centerline L1 located at the outlet edge 32 and the other end of the second centerline L2 located at the outlet edge 32, to accommodate... Figure 4 and attached Figure 5 As shown in the view, this implementation makes the air outlet edge 32 of the blade 3 form a "forward tilting" structural form.

[0038] The slightly forward-leaning exhaust edge 32 helps to smoothly discharge the airflow, reduce airflow separation and outlet vortex phenomena, further reduce energy loss at the trailing edge of the blade 3, improve exhaust efficiency, and effectively reduce flow noise.

[0039] When the backward-tilted inlet edge 31 and the forward-tilted outlet edge 32 are combined, a smoother streamlined guiding effect can be formed in the overall aerodynamic layout of the blades 3. This effectively balances the changes in airflow angle between the inlet and outlet areas, reduces airflow separation on the surface of the blades 3, optimizes pressure distribution, and reduces the formation of local negative pressure zones, thereby further improving the continuity of airflow and the stability of the flow field. It significantly improves the matching of airflow injection angles at different radii, reduces angle-of-attack losses, and significantly improves the fan efficiency and airflow and pressure output performance. Furthermore, this combination design not only helps improve aerodynamic performance but also reduces noise and vibration caused by flow field fluctuations, significantly improving the overall operational reliability and service life of the impeller.

[0040] In other embodiments, the inlet angle of the blade 3 gradually increases from the end near the first disc 1 to the end near the second disc 2. Based on knowledge in the art, as shown in the appendix... Figure 6 and attached Figure 7 As shown, the inlet angle is defined as the angle between the tangent of the arc line of blade 3 (simplified here as the arc line of the cross section of blade 3) located at the end of the inlet edge 31 and the tangent of the arc line of blade 3 itself at that end with the impeller center as the center.

[0041] In this improvement, the two ends of blade 3 have different inlet angles, and in accordance with the helical twist structure of blade 3, the inlet angles at both ends of blade 3 transition smoothly. At this time, the arc at both ends of blade 3 has different inlet angles to achieve precise matching of airflow angle of attack at different radii, thereby improving airflow adhesion and overall flow smoothness.

[0042] In a further embodiment, the blade 3 has a root inlet angle α1 at the end near the first disc 1, where α1 satisfies 55.5° ≤ α1 ≤ 57.5°; the blade 3 has a top inlet angle α2 at the end near the second disc 2, where α2 satisfies 59° ≤ α1 ≤ 61°. Along the axial direction of the blade 3, the inlet angle at the air inlet edge 31 of the blade 3 gradually changes from α1 to α2. In a preferred embodiment, α2 is 60° and α1 is 56.5°, thereby further optimizing the airflow guidance performance.

[0043] In a similar embodiment, the exit angle of blade 3 gradually increases from the end closer to the first disc 1 to the end closer to the second disc 2. Based on knowledge in the art, as shown in the appendix... Figure 6 and attached Figure 7 As shown, similar to the inlet angle, the outlet angle is defined as the angle between the tangent of the arc line of blade 3 (simplified here as the arc line of the cross section of blade 3) located at the end point of the outlet edge 32 and the tangent of the arc line at that end point with the impeller center as the center.

[0044] In this improvement, the two ends of blade 3 have different exit angles, and in accordance with the helical twist structure of blade 3, the exit angles at both ends of blade 3 transition smoothly. At this time, the arc at both ends of blade 3 has different exit angles to achieve precise matching of airflow angle of attack at different radii, thereby improving airflow adhesion and overall flow smoothness.

[0045] In a further embodiment, the blade 3 has a root exit angle β1 at the end near the first disc 1, where β1 satisfies 159°≤β1≤161°; the blade 3 has a top exit angle β2 at the end near the second disc 2, where β2 satisfies 170°≤β2≤172°. Along the axial direction of the blade 3, the exit angle at the air outlet edge 32 of the blade 3 gradually changes from β1 to β2. In a preferred embodiment, β2 is 171° and β1 is 160°, thereby further optimizing airflow guidance performance.

[0046] When the aforementioned inlet and outlet angles are set in combination, the inlet edge 31 of the blade 3 is tilted backward from the first disc 1 to the second disc 2, and the outlet edge 32 of the blade 3 is tilted forward from the first disc 1 to the second disc 2. This geometric optimization significantly enhances the aerodynamic adaptability and operating efficiency of the impeller under multiple operating conditions.

[0047] Example 2

[0048] Combined with appendix Figure 8 This embodiment proposes a multi-blade centrifugal fan, including the impeller structure described in the technical solution of embodiment 1, and also includes an impeller disk 4, with the first disk 1 fixedly connected to the impeller disk 4.

[0049] Example 3

[0050] This embodiment of a multi-blade centrifugal fan includes the multi-blade centrifugal fan described in the technical solution of embodiment 2.

[0051] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A structure of impeller, comprising oppositely arranged first disc (1) and second disc (2), and several blades (3) fixed in uniform array along the ring direction between the first disc (1) and the second disc (2), characterized in that, The blade (3) has an arc-shaped cross section and the blade (3) is spirally twisted from the end near the first disk (1) to the end near the second disk (2); The blade (3) has a first center line L1 at one end near the first disk (1) and a second center line L2 at one end near the second disk (2). The projections of the first center line L1 and the second center line L2 on the blade length direction intersect at an intersection point P. The intersection point P, the midpoint m1 of the first center line L1 and the midpoint m2 of the second center line L2 do not coincide at the same time.

2. The impeller structure according to claim 1, characterized in that, The side of the blade (3) closest to the center of its circumferential array is the air inlet side (31), which is inclined toward the convex side of the blade (3).

3. The impeller structure according to claim 1, characterized in that, The side of the blade (3) facing away from the center of its circumferential array is the air outlet edge (32), which is inclined toward the concave side of the blade (3).

4. The impeller structure according to claim 1, characterized in that, The inlet angle of the blade (3) gradually increases from the end closer to the first disc (1) to the end closer to the second disc (2).

5. The impeller structure according to claim 4, characterized in that, The blade (3) has a root inlet angle α1 at the end near the first disc (1), where α1 satisfies 55.5°≤α1≤57.5°; the blade (3) has a top inlet angle α2 at the end near the second disc (2), where α2 satisfies 59°≤α1≤61°.

6. The impeller structure according to claim 1, characterized in that, The exit angle of the blade (3) gradually increases from the end closer to the first disc (1) to the end closer to the second disc (2).

7. The impeller structure according to claim 6, characterized in that, The blade (3) has a root exit angle β1 at the end near the first disk (1), where β1 satisfies 159°≤β1≤161°; the blade (3) has a top exit angle β2 at the end near the second disk (2), where β2 satisfies 170°≤β2≤172°.

8. A multi-blade centrifugal fan, comprising the impeller structure according to any one of claims 1-7, characterized in that, It also includes an impeller (4), with the first disc (1) fixedly connected to the impeller (4).

9. A multi-blade centrifugal fan, characterized in that, Including the multi-blade centrifugal fan as described in claim 8.

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