Impeller and centrifugal fan comprising same
By cutting transition sections on the impeller blades and increasing the outlet angle, the problems of uneven blade work and vortex formation are solved, thus improving the efficiency and performance of the centrifugal fan.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NINGBO FOTILE KITCHEN WARE CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-06-26
AI Technical Summary
In existing multi-blade centrifugal fans, the impeller blades work unevenly at high speeds, resulting in reduced fan efficiency. Furthermore, vortex zones are prone to form near the front plate of the volute, affecting fan performance.
Design an impeller in which the blades are cut along the chord direction near the front plate to form a transition section. The exit angle of the transition section is greater than the exit angle of the main blade segment, which increases the airflow velocity, reduces the formation of vortices, and improves the work capacity.
By improving the blade structure, the overall work capacity of the impeller and the efficiency of the fan are enhanced, eddies are reduced, and the performance of the centrifugal fan is improved.
Smart Images
Figure CN224413945U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of power devices, and in particular to an impeller and a centrifugal fan containing the impeller. Background Technology
[0002] The multi-blade centrifugal fan is the core power component of a range hood, providing air intake capacity. Its aerodynamic performance directly determines the range hood's smoke extraction ability. The impeller, as the main working component of the multi-blade centrifugal fan, directly affects key indicators such as airflow, air pressure, and noise levels.
[0003] During operation, the impeller draws in oil fumes while expelling airflow. Due to the suction force of the impeller, the airflow drawn into the fan system has a certain velocity and typically flows towards the rear plate of the impeller before spreading towards the front plate. This phenomenon is more pronounced when the impeller size is small and the rotational speed is high, leading to uneven work distribution among the impeller blades. Specifically, the work done by the blades is mainly concentrated at the rear plate, while the blades at the shallower plate have weaker work capacity, thus significantly limiting the overall work capacity of the impeller. Furthermore, because the airflow velocity is higher near the rear plate of the impeller within the volute casing compared to the lower velocity at the front plate, a large vortex area often forms on the wall of the volute casing near the front plate, which to some extent affects the efficiency of the fan system. Utility Model Content
[0004] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide an impeller and a centrifugal fan containing the impeller.
[0005] The present invention solves the above-mentioned technical problems through the following technical solution:
[0006] An impeller for a centrifugal fan, the impeller comprising a front disc, a rear disc, and blades, the blades being connected to the front disc and the rear disc, the blades being cut along the chordal direction of the blades from the outlet end toward the inlet end of the blades near the front disc to form a transition section near the front disc and a main blade segment near the rear disc along the axial direction of the impeller, the transition section being partially connected to the main blade segment along the chordal direction;
[0007] The exit angle of the transition section is greater than the exit angle of the main leaf segment.
[0008] In this technical solution, by cutting the blades to form a transition section and a main blade segment, and setting the outlet angle of the transition section to be greater than that of the main blade segment, the airflow velocity in the transition zone is increased, avoiding the formation of a large vortex area near the wall of the volute near the front plate, thereby improving the work capacity of the transition section, and thus improving the overall work capacity of the impeller and increasing the efficiency of the centrifugal fan using this impeller.
[0009] Preferably, the difference between the exit angle of at least a portion of the transition section and the exit angle of the main leaf segment is a, where a ≥ 3°.
[0010] In this technical solution, by setting the difference between the exit angle of at least a portion of the transition section and the exit angle of the main blade segment to at least 3°, the effect of increasing the flow velocity of the airflow from the transition section to the volute is more obvious, thereby better reducing the vortex near the volute and the front plate.
[0011] Preferably, the difference between the exit angle of the transition section and the exit angle of the main leaf segment is a, where a ≤ 6°.
[0012] In this technical solution, by setting the difference between the exit angle of at least a portion of the transition section and the exit angle of the main blade segment to no more than 6°, a large energy loss due to an excessively large exit angle is avoided, thus achieving a better balance between increasing airflow velocity and avoiding energy loss.
[0013] Preferably, the chord length is c0, and the cutting depth along the chord length direction between the transition segment and the main leaf segment is c1, where c1 ≥ ( )c0.
[0014] In this technical solution, by setting the cutting depth of the blade to be no less than one-third of the chord length, the processing of the transition section is made more convenient.
[0015] Preferably, the cutting depth along the chord length direction between the transition segment and the main leaf segment is c1, where c1 ≤ ( )c0.
[0016] In this technical solution, by setting the cutting depth of the blade to no more than two-thirds of the chord length, the connection between the main blade segment and the transition segment is prevented from being weak.
[0017] Preferably, the exit angle of the transition section remains unchanged along the axial direction from the rear disc toward the front disc.
[0018] In this technical solution, by setting the exit angle of the transition section to remain constant, processing becomes more convenient.
[0019] Preferably, the transition section is cut along the chord length direction from the exit end of the blade toward the inlet end of the blade to form a plurality of sub-transition sections distributed along the axial direction, and the adjacent sub-transition sections are partially connected along the chord length direction.
[0020] In this technical solution, by dividing the transition section into multiple sub-transition sections, each of which can be independently set with an exit angle, the exit angle at different positions of the blade can be made more suitable for the working conditions, thereby further improving the efficiency of the impeller.
[0021] Preferably, for different sub-transition sections, the exit angle of the sub-transition section gradually increases along the direction away from the rear plate.
[0022] In this technical solution, since the work capacity of the blades is weaker and the airflow velocity is lower the further away from the rear disk, the exit angle of different sub-transition sections gradually increases along the direction away from the rear disk, and the effect of improving the airflow velocity is better, thereby improving the uniformity of the airflow velocity at all points along the axial direction of the transition section.
[0023] Preferably, along the axial direction, the distance between the front plate and the rear plate is m, and the length of the transition section along the axial direction is n, where n ≥ 0.1m.
[0024] In this technical solution, by setting the axial length of the transition section to at least 0.1 times the distance between the front and rear discs, the overall work capacity of the blade is better.
[0025] Preferably, the distance between the front plate and the rear plate is m, and the length of the transition section along the axial direction is n, where n ≤ 0.4m.
[0026] In this technical solution, the axial length of the transition section is set to no more than 0.4 times the distance between the front and rear discs to avoid over-processing.
[0027] Preferably, the inlet angle of the transition section is equal to the inlet angle of the main leaf segment.
[0028] Preferably, the front disc includes a first front disc and a second front disc, the first front disc, the rear disc and the second front disc are arranged sequentially at intervals along the axial direction, the blade is sequentially connected to the first front disc, the rear disc and the second front disc, and the transition section includes a first transition section and a second transition section, the first transition section is close to the first front disc and the second transition section is close to the second front disc.
[0029] In this technical solution, by setting two front discs, the impeller has dual air inlets, increasing the impeller's airflow. Simultaneously, by setting transition sections near both the first and second front discs, the work capacity at both ends of the blades along the axial direction is enhanced, thereby improving the impeller's efficiency.
[0030] Preferably, the distance between the first transition section and the rear plate is L1, and the distance between the second transition section and the rear plate is L2, where L1 > L2;
[0031] The maximum value of the exit angle of the first transition section is greater than the maximum value of the exit angle of the second transition section.
[0032] In this technical solution, the distance L1 between the first transition section and the rear plate is greater than the distance L2 between the second transition section and the rear plate. The maximum value of the exit angle of the first transition section is greater than the maximum value of the exit angle of the second transition section. In other words, the farther the transition section is from the rear plate, the greater the increase in its exit angle relative to the exit angle of the main blade segment, and the better the effect on improving the uniformity of airflow velocity.
[0033] A centrifugal fan, the centrifugal fan comprising the impeller as described above.
[0034] In this technical solution, by setting the aforementioned impeller, the vortex near the front plate of the centrifugal fan casing can be reduced, thereby improving the efficiency of the centrifugal fan.
[0035] The positive and progressive effects of this utility model are as follows: by setting a transition section near the front plate of the blade, setting the inlet angle of the transition section to be greater than the inlet angle of the main blade segment, and setting the outlet angle of the transition section to be greater than the outlet angle of the main blade segment, the airflow velocity in the transition zone is increased, avoiding the formation of a large vortex area on the wall surface of the volute near the front plate, thereby improving the work capacity of the transition section, and further improving the overall work capacity of the impeller, thus increasing the efficiency of the centrifugal fan using this impeller. Attached Figure Description
[0036] Figure 1 This is a three-dimensional structural diagram of an impeller according to an embodiment of the present invention.
[0037] Figure 2 for Figure 1 Enlarged view of section A.
[0038] Figure 3 This is a side view of an impeller according to an embodiment of the present invention.
[0039] Figure 4 This is a side view of a blade according to an embodiment of the present invention.
[0040] Figure 5 This is a schematic diagram of the impeller passage of an embodiment of the present invention.
[0041] Figure 6 for Figure 5 Enlarged view of section B in the middle.
[0042] Explanation of reference numerals in the attached figures:
[0043] Impeller 100
[0044] Leaf 2
[0045] Primary leaf segment 21
[0046] Transition section 22
[0047] Import end 201
[0048] Export end 202
[0049] Front board 3
[0050] First front plate 31
[0051] Second front board 32
[0052] Backboard 4
[0053] chord length direction C Detailed Implementation
[0054] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.
[0055] This embodiment provides a centrifugal fan, which includes a volute and an impeller 100. The impeller 100 includes a front disc 3, a rear disc 4, and blades 2. The blades 2 are connected to the front disc 3 and the rear disc 4. Multiple blades 2 are arranged at circumferential intervals along the impeller 100. Figures 1-6 As shown, the impeller 100 in the figure is for illustrative purposes only. Figure 1 The diagram only shows the structure of any one of the blades, 2. Figure 5 The diagram only shows the structure of any two adjacent blades forming an air passage. Near the front disk 3, blade 2 is cut along the chordal direction C from its exit end 202 towards its inlet end 201 to form a transition section 22 near the front disk 3 and a main blade segment 21 near the rear disk 4 along the axial direction of the impeller 100. Along the chordal direction C, the transition section 22 is partially connected to the main blade segment 21, and the exit angle of the transition section 22 is greater than the exit angle of the main blade segment 21. By cutting blade 2 to form the transition section 22 and the main blade segment 21, and setting the exit angle of the transition section 22 to be greater than the exit angle of the main blade segment 21, as shown... Figure 5 and Figure 6 As shown, Figure 6 H represents the width of the leaf canal of the primary leaf segment. Figure 6 h represents the width of the blade passage at the outlet angle of the transition section 22. H > h, which means that when the outlet angle of the blade increases, the size of the blade passage decreases. Therefore, by setting the outlet angle of the transition section 22 to be greater than the outlet angle of the main blade segment 21, the airflow velocity of the transition section 22 is increased, avoiding the formation of a large vortex area near the wall of the front plate 3 of the volute, thereby improving the work capacity of the transition section 22, and thus improving the overall work capacity of the impeller 100 and increasing the efficiency of the centrifugal fan using the impeller 100.
[0056] Specifically, the difference between the exit angle of the transition section 22 and the exit angle of the main blade segment 21 is 'a', with an optimal range of 3° ≤ a ≤ 6°. By setting the difference between at least a portion of the exit angle of the transition section 22 and the exit angle of the main blade segment 21 to at least 3°, the effect of increasing the velocity of the airflow from the transition section 22 to the volute is more significant, thereby better reducing the vortex near the volute and the front plate 3. By setting the difference between at least a portion of the exit angle of the transition section 22 and the exit angle of the main blade segment 21 to no more than 6°, significant energy loss due to an excessively large exit angle is avoided, achieving a better balance between increasing airflow velocity and avoiding energy loss.
[0057] In this embodiment, as Figure 1 and Figure 4 As shown, along the axial direction from the rear plate 4 to the front plate 3, the exit angle of the transition section 22 remains unchanged, a=5°. By setting the exit angle of the transition section 22 to remain unchanged, the processing is more convenient.
[0058] Of course, in other embodiments, 'a' can also take other values. Simultaneously, the transition section 22 can be cut along the chord direction C from the outlet end 202 of the blade 2 toward the inlet end 201 of the blade 2 to form multiple sub-transition sections distributed axially. Along the chord direction C, adjacent sub-transition sections are partially connected. By cutting the transition section 22 into multiple sub-transition sections, each sub-transition section can have its outlet angle independently set, making the outlet angles at different positions of the blade 2 more suitable for the operating conditions, further improving the efficiency of the impeller 100.
[0059] In further embodiments, when the transition section 22 is divided into multiple sub-transition sections, the exit angle of each sub-transition section gradually increases along the direction away from the rear disk 4. Since the work capacity of the blade 2 decreases and the airflow velocity decreases with increasing distance from the rear disk 4, the gradual increase in the exit angle of each sub-transition section along the direction away from the rear disk 4 has a better effect on improving the airflow velocity, thereby improving the uniformity of the airflow velocity at all points along the axial direction of the transition section 22.
[0060] In this embodiment, the blade 2 is a technical variation of the two-dimensional blade 2 in the prior art. Based on the two-dimensional blade 2 of the prior art, the blade 2 is cut to form a transition section 22 and a main blade segment 21. Then, the transition section 22 is bent using a processing method in the prior art, so that the exit angle of the transition section 22 is greater than the exit angle of the main blade segment 21. The inlet section of the blade 2 is not cut, and the inlet angle of the transition section 22 remains consistent with the inlet angle of the main blade segment 21.
[0061] like Figure 3 and Figure 4As shown, for the cutting depth on blade 2, the chord length of blade 2 is c0, and the cutting depth along the chord length direction C between transition segment 22 and main blade segment 21 is c1. The optimal range of values for c1 is: By setting the cutting depth of blade 2 to no less than one-third of the chord length, the processing of transition segment 22 is made easier. By setting the cutting depth of blade 2 to no more than two-thirds of the chord length, the connection between main blade segment 21 and transition segment 22 is prevented from being weak.
[0062] Specifically in this embodiment, .
[0063] Of course, in other embodiments, the cutting depth can also be set to other values, as long as it ensures that the transition segment 22 and the main leaf segment 21 can still be reliably connected after cutting.
[0064] For the length of transition segment 22, such as Figure 3 As shown, the distance between the front disc 3 and the rear disc 4 along the axial direction is m, and the length of the transition section 22 along the axial direction is n, with the preferred value range of n being 0.1m ≤ n ≤ 0.4m. Setting the axial length of the transition section 22 to at least 0.1 times the distance between the front disc 3 and the rear disc 4 improves the overall work capacity of the blade 2. Setting the axial length of the transition section 22 to no more than 0.4 times the distance between the front disc 3 and the rear disc 4 avoids over-processing.
[0065] Specifically, in this embodiment, n=0.3m.
[0066] In this embodiment, the centrifugal fan is a dual-inlet centrifugal fan. Both ends of the impeller 100 are configured as air inlets. The front disc 3 includes a first front disc 31 and a second front disc 32, which are sequentially spaced along the axial direction. The blades 2 are sequentially connected to the first front disc 31, the rear disc 4, and the second front disc 32. By providing two front discs 3, the impeller 100 has dual air inlets, increasing the airflow of the impeller 100.
[0067] Specifically, in this embodiment, only the area near the first front disc 31 was cut to form the first transition section.
[0068] Of course, in other embodiments, the blade 2 can also be cut at both ends near the first front disc 31 and the second front disc 32 to form a first transition section near the first front disc 31 and a second transition section near the second front disc 32. By providing transition sections 22 at both ends near the first front disc 31 and the second front disc 32, the work capacity at both ends of the blade 2 along the axial direction is improved, thereby improving the efficiency of the impeller 100.
[0069] In further embodiments, when the blade 2 has a first transition section and a second transition section at its two ends respectively, the distance between the first transition section and the rear plate 4 is L1, and the distance between the second transition section and the rear plate 4 is L2. The maximum value of the exit angle of the first transition section can be set to be greater than the maximum value of the exit angle of the second transition section. Since the distance L1 between the first transition section and the rear plate 4 is greater than the distance L2 between the second transition section and the rear plate 4, the maximum value of the exit angle of the first transition section is greater than the maximum value of the exit angle of the second transition section. That is to say, the farther the transition section 22 is from the rear plate 4, the greater the increase in its exit angle relative to the exit angle of the main blade segment 21, and the better the effect on improving the uniformity of airflow velocity.
[0070] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.
Claims
1. An impeller for use in a centrifugal fan, the impeller comprising a front disc, a rear disc, and blades, the blades being connected to the front disc and the rear disc, characterized in that: The blade is cut along the chord length direction from the outlet end of the blade toward the inlet end of the blade near the front disk to form a transition section near the front disk along the axial direction of the impeller and a main blade segment near the rear disk. The transition section is partially connected to the main blade segment along the chord length direction. The exit angle of the transition section is greater than the exit angle of the main leaf segment.
2. The impeller of claim 1, wherein The difference between the exit angle of at least a portion of the transition section and the exit angle of the main leaf segment is a, where a ≥ 1°; And / or, the difference between the exit angle of the transition section and the exit angle of the main leaf segment is a, where a ≤ 4°.
3. The impeller as described in claim 2, characterized in that, The chord length is c0, and the cutting depth along the chord length direction between the transition segment and the main leaf segment is c1, where c1 ≥ ( c0; And / or, the cutting depth along the chord length direction between the transition segment and the main leaf segment is c1, c1≤( )c0.
4. The impeller as described in claim 2, characterized in that, Along the axial direction from the rear disc toward the front disc, the exit angle of the transition section remains unchanged.
5. The impeller as described in claim 2, characterized in that, The transition section is cut along the chord length direction from the exit end of the blade toward the inlet end of the blade to form a plurality of sub-transition sections distributed along the axial direction, and adjacent sub-transition sections are partially connected along the chord length direction.
6. The impeller as described in claim 5, characterized in that, For different sub-transition sections, the exit angle of the sub-transition section gradually increases in the direction away from the rear plate.
7. The impeller as claimed in claim 1, characterized in that, Along the axial direction, the distance between the front plate and the rear plate is m, and the length of the transition section along the axial direction is n, where n ≥ 0.1m; And / or, the distance between the front plate and the rear plate is m, and the length of the transition section along the axial direction is n, where n≤0.4m.
8. The impeller as claimed in claim 1, characterized in that, The inlet angle of the transition section is equal to the inlet angle of the main leaf segment.
9. The impeller as described in any one of claims 1-8, characterized in that, The front disc includes a first front disc and a second front disc. The first front disc, the rear disc, and the second front disc are arranged sequentially at intervals along the axial direction. The blade is sequentially connected to the first front disc, the rear disc, and the second front disc. The transition section includes a first transition section and a second transition section. The first transition section is close to the first front disc, and the second transition section is close to the second front disc.
10. The impeller as claimed in claim 9, characterized in that, The distance between the first transition section and the rear plate is L1, and the distance between the second transition section and the rear plate is L2, where L1 > L2; The maximum value of the exit angle of the first transition section is greater than the maximum value of the exit angle of the second transition section.
11. A centrifugal fan, characterized in that, The centrifugal fan includes an impeller as described in any one of claims 1-10.