Impeller, centrifugal fan and range hood
By setting the saw toothed section and smooth section on the leading and trailing edges of the blade, the contradiction between impeller airflow noise and work area is solved, and better airflow performance and noise reduction are achieved, avoiding the increase in noise caused by increasing rotation speed.
Patent Information
- Application Number
- CN202323517431.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-22
- Publication Date
- 2025-01-14
- Estimated Expiration
- 2033-12-22
AI Technical Summary
In the prior art, the blades of the impeller are provided with a sawtooth shape to improve airflow noise, but result in a reduction in work area, affecting aerodynamic performance, and increasing the noise level when the rotation speed is increased to improve workability.
Both the leading and trailing edges of the blade are provided with sawtooth segments and smooth segments adjacent to the sawtooth segments. The turbulence is increased through the sawtooth shape, low-speed airflow is mixed to high-speed airflow, reducing flow loss and noise, and taking into account the work area through the smoothing segment to improve the Fluid dynamics performance.
Synchronously reduces the impact noise at the leading edge of the blade and the trailing edge vortex shedding noise, improves the airflow performance of the impeller and avoids the increase in noise that increases the speed and improves the workmanship capacity.
Smart Images
Figure CN222351009U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of fans, and in particular to an impeller, a centrifugal fan and a range hood. Background Art
[0002] Range hoods generally use centrifugal fans as their power system to generate airflow, increase air circulation or provide wind force. As one of the core components of a centrifugal fan, the impeller plays an important role in the performance of the centrifugal fan.
[0003] In the related art, the blades of the impeller may be provided with serrations or other shape features on the entire leading edge or the entire trailing edge to improve the airflow noise. However, the serrations may reduce the working area of the blades, resulting in a reduction in air volume, thereby affecting the overall aerodynamic performance of the impeller. Utility Model Content
[0004] The embodiments of the present application provide an impeller, a centrifugal fan and a range hood, which can simultaneously reduce the impact noise of the leading edge of the blade and the vortex shedding noise of the trailing edge of the blade, and take into account the working area of the leading edge and the trailing edge of the blade, so that the airflow performance of the impeller is guaranteed.
[0005] In a first aspect, an embodiment of the present application provides an impeller, the impeller comprising:
[0006] front plate;
[0007] a rear disc, the rear disc being spaced apart from the front disc; and
[0008] A plurality of blades, opposite ends of each blade are connected to the front disk and the rear disk respectively, and the plurality of blades are distributed at intervals along the circumference of the front disk and the rear disk;
[0009] The blade has a leading edge and a trailing edge, wherein the leading edge is arranged toward the inner side of the rear disk, and the trailing edge is arranged toward the outer side of the rear disk, and both the leading edge and the trailing edge are provided with a sawtooth segment and a smooth segment arranged adjacent to the sawtooth segment.
[0010] In some embodiments, the serrated segment located at the leading edge includes a first serrated sub-segment and a second serrated sub-segment, wherein the first serrated sub-segment is located at a side of the smooth segment of the leading edge close to the front disk, and the second serrated sub-segment is located at a side of the smooth segment of the leading edge close to the rear disk;
[0011] The sawtooth segment located at the trailing edge includes a third sub-sawtooth segment and a fourth sub-sawtooth segment. The third sub-sawtooth segment is located at a side of the smooth segment of the trailing edge close to the front disk, and the fourth sub-sawtooth segment is located at a side of the smooth segment of the trailing edge close to the rear disk.
[0012] In some of the embodiments, the smooth section at the leading edge extends to the middle of the leading edge.
[0013] In some of the embodiments, the smooth section of the leading edge and the smooth section of the trailing edge are symmetrically arranged.
[0014] In some embodiments, the length L1 of the smooth section at the leading edge and the total length L2 of the blade between the front disk and the rear disk satisfy: 0.35≤L1 / L2≤0.65.
[0015] In some embodiments, the impeller further includes a middle disk, wherein the middle disk is connected to the smooth section of the leading edge and the smooth section of the trailing edge and is located between the front disk and the trailing disk.
[0016] In some embodiments, the total length of the smooth section at the front edge is L1, and the distance between one end of the smooth section close to the front disc and the middle disc is L3, satisfying: 0.5L1≤L3≤L1.
[0017] In some embodiments, the center of the smooth section at the leading edge and the center of the distance between the front disk and the rear disk is L4, and the total length L1 of the smooth section at the leading edge satisfies: L4≤1 / 5L1.
[0018] In some embodiments, the smooth segment is a straight line segment setting or an arc segment setting;
[0019] And / or, the shape of the teeth of the sawtooth segment is rectangular, arc-shaped or angular.
[0020] In a second aspect, an embodiment of the present application provides a centrifugal fan, which includes a volute and an impeller as described above, wherein the volute is provided with a accommodating cavity and an air inlet and an air outlet respectively connected to the accommodating cavity, and the impeller is located in the accommodating cavity.
[0021] In a third aspect, an embodiment of the present application provides a range hood, comprising a casing and a centrifugal fan as described above, wherein the centrifugal fan is installed in the casing.
[0022] Based on the impeller, centrifugal fan and range hood of the embodiment of the present application, by providing a sawtooth segment and a smooth segment adjacent to the sawtooth segment on both the leading edge and the trailing edge of the blade, the impeller of the embodiment has the following effects:
[0023] First, the sawtooth shape of the sawtooth section of the leading edge can further increase the degree of turbulence when the airflow flows, so that the low-speed airflow in the impeller is more easily mixed into the high-speed airflow, so that the airflow flows through the leading edge more smoothly, reducing the flow impact of the airflow at the leading edge, reducing flow losses, and reducing the airflow impact noise at the leading edge.
[0024] Second, the serrated shape of the serrated section of the trailing edge changes the position where the trailing vortex of the blade falls off, thereby increasing the distance between the vortex centers, suppressing the disturbance of the shedding vortex to the trail flow, and further reducing the aerodynamic noise caused by the trail vortex.
[0025] Third, the smooth sections of the leading and trailing edges of the blades are set to reduce the impact noise of the leading edge of the blades and the vortex shedding noise of the trailing edge of the blades while ensuring the working area of the blades. This can improve the working capacity without increasing the speed of the impeller, thereby providing better fluid dynamics performance and ensuring the airflow performance of the impeller. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.
[0027] Figure 1 This is a schematic structural diagram of an embodiment of a centrifugal fan of the present application;
[0028] Figure 2 This is a schematic diagram of the structure of the impeller of this application;
[0029] Figure 3 This is a schematic diagram of the structure of the blades of the impeller of this application;
[0030] Figure 4 This is a structural schematic diagram of the impeller of this application from another perspective.
[0031] Description of Figure Numbers:
[0032] 1000, centrifugal fan; 100, impeller; 10, front disc; 20, rear disc; 30, blade; 31, leading edge; 311, first serrated sub-segment; 312, second serrated sub-segment; 32, trailing edge; 321, third serrated sub-segment; 322, fourth serrated sub-segment; 33, connecting foot; 30a, serrated segment; 30b, smooth segment; 40, middle disc; 200, volute; 201, air inlet; 202, air outlet; 300, motor.
[0033] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION
[0034] In order to make the objectives, technical solutions and advantages of the present application clearer, the following part will further describe the embodiments of the present application in detail in conjunction with the accompanying drawings.
[0035] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.
[0036] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.
[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0038] Range hoods generally use centrifugal fans as their power system to generate airflow, increase air circulation or provide wind force. As one of the core components of the fan, the impeller plays an important role in the performance of the fan.
[0039] In the related technology, the blades of the impeller are provided with shape features such as serrations to improve the airflow disturbance at the leading edge and the large-scale vortex shedding at the trailing edge. However, the serration setting will reduce the working area of the blades, resulting in a certain reduction in air volume. In order to ensure that the air volume meets the standard, the workmanship must be improved by increasing the rotation speed, which in turn increases the noise level and affects the user experience.
[0040] To solve the above problems, the first aspect of the present application proposes a range hood. In an embodiment of the present application, the range hood includes a casing and a centrifugal fan. A flue is provided in the casing, and the centrifugal fan is arranged in the flue of the casing. When the range hood is working, it can absorb the oil smoke, water vapor, etc. generated during cooking into the flue through the centrifugal fan and discharge them outdoors.
[0041] The second aspect of the present application provides a centrifugal fan 1000, Figure 1The centrifugal fan 1000 includes a volute 200, an impeller 100 and a motor 300. The volute 200 is provided with a containing cavity and an air inlet 201 and an air outlet 202 respectively connected to the containing cavity. The volute 200 can guide and expand the smoke. The motor 300 and the impeller 100 are both arranged in the volute 200, and the motor 300 and the impeller 100 are transmission-coordinated so that when the range hood is working, the motor 300 can be used to drive the impeller 100 to rotate at a high speed to generate negative pressure to suck the smoke from the air inlet 201 into the volute 200, and the centrifugal force generated during the rapid rotation of the impeller 100 can quickly discharge the smoke, water vapor, etc. from the volute 200 through the air outlet 202.
[0042] In order to increase the workability of the impeller 100 and reduce the working noise, the present application focuses on improving the impeller 100. Figures 2 to 4 In the embodiment of the present application, the impeller 100 may include a front disk 10 , a rear disk 20 , and a plurality of blades 30 .
[0043] The rear disc 20 is arranged at a distance from the front disc 10. The front disc 10 and the rear disc 20 constitute the basic framework of the impeller 100. The front disc 10 and the rear disc 20 are arranged in an annular plate-like structure, and the annular accommodation space between the front disc 10 and the rear disc 20 forms a centrifugal air outlet channel. When the impeller 100 rotates, the airflow flows from the inner ring side of the front disc 10 and the rear disc 20 to the outer ring side under the action of centrifugal force, so that the air inlet 201 of the volute 200 is arranged opposite to the inner ring side of the front disc 10 and the rear disc 20, and the air outlet 202 of the volute 200 is located on the outer ring side of the front disc 10 and the rear disc 20. The outer contour dimensions of the front disc 10 and the rear disc 20 can be the same, and the materials used for the front disc 10 and the rear disc 20 can also be the same, both of which are made of high-strength metal materials, such as aluminum alloy or carbon steel. The opposite ends of each blade 30 are connected to the front disk 10 and the rear disk 20 respectively, and the plurality of blades 30 are spaced apart along the circumference of the front disk 10 and the rear disk 20, and a flow channel for fluid to flow through is provided between two adjacent blades 30. The connection between the front disk 10 and the rear disk 20 and the blades 30 may be a detachable connection to facilitate the maintenance and replacement of the blades 30. The number of blades 30 may be 48, 56, or 64, etc., so that the working capacity of the blades 30 can be fully utilized, and the air flow channel between adjacent blades 30 is wider, and the separation vortex is not easy to block the channel, which can improve the flow efficiency.
[0044] The blade 30 may be arranged in the shape of a long strip, and has a leading edge 31 and a trailing edge 32 on opposite sides of the length direction of the blade 30. The leading edge 31 is arranged toward the inner side of the rear disc 20, that is, toward the air inlet direction, and the trailing edge 32 is arranged toward the outer side of the rear disc 20, that is, toward the air outlet direction. The material of the blade 30 may be a metal alloy, such as stainless steel or aluminum alloy, so as to have good corrosion resistance and high strength. The leading edge 31 and the trailing edge 32 are both provided with a sawtooth section 30a and a smooth section 30b arranged adjacent to the sawtooth section 30a. The sawtooth section 30a and the smooth section 30b may be an integral structure, so as to ensure the stability of the overall structure of the blade 30. It is understood that the smooth section 30b generally refers to an area without sawtooth, protrusion or other protruding structures. Such a smooth section 30b helps to reduce the turbulence and separation of the airflow and improve the aerodynamic efficiency of the blade 30. A chamfer is set at one end of the leading edge 31 close to the front disk 10, and the chamfer means that the edge or angle of the leading edge 31 of the blade 30 is designed not to be perpendicular to the direction of the blade 30, but to have an inclination of a chamfer. This means that by introducing a chamfer at the leading edge 31 of the blade 30, the inlet circle diameter of the impeller 100 can be affected. The inlet circle diameter refers to the area where the air flows through the impeller 100, and increasing the inlet circle diameter helps to improve the performance of the impeller 100.
[0045] Please refer to Figures 2 to 4 In some structural forms, the smooth section 30b can be a straight section extending along the length direction of the blade 30, so as to facilitate processing and manufacturing, which helps to reduce production costs. And the straight section can provide better structural stability, especially in applications that process high-speed fluids. Of course, the smooth section 30b can also be an arc segment that is convex or concave, and the arc segment can reduce the turbulence and separation of the airflow on the surface of the blade 30, which helps to reduce aerodynamic losses and improve efficiency. And the arc shape can also play a role in guiding the airflow, so as to help reduce aerodynamic noise and vibration, improve the working stability of the blade 30, and reduce the mechanical noise level.
[0046] Optionally, the shape of the teeth of the sawtooth segment 30a is rectangular, arc-shaped or angular. That is, as long as the teeth of the sawtooth portions of the leading edge 31 and the trailing edge 32 of the blade 30 can break up the airflow mass, the shape can be as described above, and a suitable tooth shape can be selected according to production requirements, process requirements and cost requirements.
[0047] Reference Figure 3Optionally, connecting pins 33 are provided at both ends of the length direction of the blade 30, and the front disc 10 and the rear disc 20 are respectively provided with a plurality of mounting grooves opposite to each other, and the connecting pins 33 of the blade 30 are inserted into the mounting grooves and matched with the mounting grooves. Specifically, the connecting pins 33 provided at both ends of the length direction of the blade 30 may be block-shaped, and the mounting grooves are adapted to the connecting pins 33 of the blade 30, and are relatively arranged on the front disc 10 and the rear disc 20, and a plurality of mounting grooves are adapted to the front disc 10 and the rear disc 20 according to the number of the blades 30. The matching between the connecting pins 33 of the blade 30 and the mounting grooves of the front disc 10 and the rear disc 20 may be directly inserted into the mounting grooves by interference fit, or may be passed through the mounting grooves, with the ends of the connecting pins 33 located on the other side of the front disc 10 and the other side of the rear disc 20, and then fixed to the front disc 10 and the rear disc 20 by bending the connecting pins 33, or the connecting pins 33 and the mounting grooves are riveted.
[0048] Furthermore, two connecting pins 33 are arranged at intervals at both ends of the length direction of the blade 30. The front disc 10 and the rear disc 20 correspond to the blade 30, and multiple groups of two mounting grooves are arranged at intervals in the circumferential direction. Specifically, the blade 30 has a certain width, so in order to ensure the strength of the blade 30 after being connected to the front disc 10 and the rear disc 20, it is preferred to arrange two connecting pins 33 at each end of the length direction of the blade 30, and then arrange multiple groups of mounting grooves on the front disc 10 and the rear disc 20, and the number of each group of mounting grooves is two, so as to be able to adapt to the connecting pins 33 on the blade 30.
[0049] Based on the impeller 100, the centrifugal fan 1000 and the range hood according to the embodiment of the present application, by providing the sawtooth segment 30a and the smooth segment 30b adjacent to the sawtooth segment 30a on both the leading edge 31 and the trailing edge 32 of the blade 30, the impeller 100 according to the embodiment of the present application has the following effects:
[0050] First, the sawtooth shape of the sawtooth section 30a of the leading edge 31 can further increase the degree of turbulence when the airflow flows, so that the low-speed airflow in the impeller 100 is more easily mixed into the high-speed airflow, so that the airflow flows through the leading edge 31 more smoothly, reducing the flow impact of the airflow at the leading edge 31, reducing flow losses, and reducing the airflow impact noise at the leading edge 31.
[0051] Second, the sawtooth shape of the sawtooth section 30a of the trailing edge 32 changes the position where the wake vortex of the trailing edge 32 of the blade 30 falls off, thereby increasing the distance between the vortex centers, suppressing the disturbance of the shedding vortex to the wake flow, and further reducing the aerodynamic noise caused by the wake vortex.
[0052] Third, the smooth sections 30b of the leading edge 31 and the trailing edge 32 of the blade 30 are arranged to ensure the working area of the blade 30 while reducing the impact noise of the leading edge 31 of the blade 30 and the vortex shedding noise of the trailing edge 32 of the blade 30, so that the working capacity can be improved without increasing the rotation speed of the impeller 100, so as to provide better fluid dynamics performance, so that the airflow performance of the impeller 100 is guaranteed.
[0053] Please refer to Figures 2 to 4 Optionally, the sawtooth segment 30a at the leading edge 31 includes a first sawtooth sub-segment 311 and a second sawtooth sub-segment 312, wherein the first sawtooth sub-segment 311 is located at a side of the smooth segment 30b of the leading edge 31 close to the front disc 10, and the second sawtooth sub-segment 312 is located at a side of the smooth segment 30b of the leading edge 31 close to the rear disc 20. That is, sawtooth sub-segments are provided at opposite ends of the smooth segment 30b of the leading edge 31, so that the opposite ends of the smooth segment 30b can reduce the flow impact of the airflow at the leading edge 31, so as to further reduce the airflow noise.
[0054] The sawtooth segment 30a located at the trailing edge 32 includes a third sub-sawtooth segment 30a and a fourth sub-sawtooth segment 30a, wherein the third sub-sawtooth segment 30a is located at a side of the smooth segment 30b of the trailing edge 32 close to the front disk 10, and the fourth sub-sawtooth segment 30a is located at a side of the smooth segment 30b of the trailing edge 32 close to the rear disk 20. That is, sawtooth sub-segments are provided at opposite ends of the smooth segment 30b of the trailing edge 32, so that the opposite ends of the smooth segment 30b can suppress the disturbance of the shedding vortex to the wake flow, thereby further reducing the aerodynamic noise caused by the wake vortex.
[0055] Further, the shapes of the teeth of the first sawtooth sub-segment 311, the second sawtooth sub-segment 312, the third sub-segment 30a and the fourth sub-segment 30a. This means that the specific shapes of the sawtooth in these four sawtooth segments 30a are consistent. This design choice may be to maintain consistent aerodynamic characteristics or structural characteristics at the corresponding positions of the leading edge 31 and the trailing edge 32 of the entire blade 30. This consistent design may have the following advantages:
[0056] Aerodynamic performance consistency: The same shape of the serrated sub-segments can ensure the consistency of aerodynamic characteristics at different parts of the blade 30, which helps to improve the overall performance.
[0057] Consistency of flow control: Sawtooth sub-segments of the same shape may provide similar flow control characteristics, making the fluid dynamic behavior more consistent in different regions of the blade 30 .
[0058] Simplification of manufacturing and maintenance: If the teeth of the four sawtooth sub-segments have the same shape, manufacturing and maintenance may be less difficult because the same process and processing tools can be used.
[0059] In some structural forms, the smooth section 30b located at the leading edge 31 extends to the middle of the leading edge 31. It is understandable that when the airflow passes through the blade 30, the air volume in the middle of the blade 30 will be greater than the air volume at the two ends, that is, the middle of the blade 30 is the main working area, and the two ends are the secondary working areas, so that the smooth section 30b extends to the middle of the leading edge 31, thereby ensuring the work area of the middle of the leading edge 31 of the blade 30, so as to further improve the workability of the blade 30. Specifically, the middle of the leading edge 31 can be a smooth section 30b, and the two ends of the leading edge 31 are serrated sections 30a. In this way, the workability of the leading edge 31 is taken into account, and the flow impact of the airflow at the leading edge 31 is reduced. Similarly, the trailing edge 32 can also be a smooth section 30b in the middle, and the two ends of the trailing edge 32 are serrated sections 30a. That is, the aerodynamic noise caused by the wake vortex is reduced, and the workability of the trailing edge 32 is taken into account.
[0060] Reference Figure 3 and Figure 4 Optionally, the smooth section 30b of the leading edge 31 and the smooth section 30b of the trailing edge 32 are symmetrically arranged. In this way, the smooth section 30b of the leading edge 31 and the smooth section 30b of the trailing edge 32 have the same shape and position, which helps to maintain the balance of the entire blade 30, so that the smooth section 30b of the leading edge 31 and the smooth section 30b of the trailing edge 32 maintain consistent aerodynamic performance under different working conditions.
[0061] Furthermore, the length L1 of the smooth section 30b at the leading edge 31 and the total length L2 of the blade 30 between the front disk 10 and the rear disk 20 satisfy: 0.35≤L1 / L2≤0.65. When the ratio of the length L1 of the smooth section 30b at the leading edge 31 to the total length L2 of the leading edge 31 is less than 0.35, the length of the smooth section 30b is shorter, which cannot effectively guarantee the working area of the blade 30. When the ratio of the length L1 of the smooth section 30b at the leading edge 31 to the total length L2 of the leading edge 31 is greater than 0.65, the length of the smooth section 30b is longer, which will result in a shorter length of the serrated section 30a, which will result in a greater impact on the airflow at the leading edge 31 and a higher loss of airflow. Therefore, by limiting the ratio of the length L1 of the smooth section 30b of the leading edge 31 to the total length of the leading edge 31 to be between 0.35 and 0.65, the flow loss at the leading edge 31 can be reduced, and the airflow impact noise at the leading edge 31 can be reduced, while ensuring the work area of the leading edge 31 of the blade 30, so that the airflow performance of the impeller 100 is guaranteed. Further, when the smooth section 30b of the leading edge 31 and the smooth section 30b of the trailing edge 32 are symmetrically arranged, by limiting the length of the smooth section 30b of the leading edge 31, the specific length of the smooth section 30b of the trailing edge 32 can be simultaneously limited, so as to simultaneously ensure that the disturbance effect of the shedding vortex on the wake flow is suppressed, and the work area of the trailing edge 32 of the blade 30 is guaranteed.
[0062] Please refer to Figures 1 to 4 In some structural forms, the impeller 100 further includes a middle plate 40, which is connected to the smooth section 30b of the leading edge 31 and the smooth section 30b of the trailing edge 32, and is located between the front plate 10 and the rear plate 20. The middle plate 40 coincides with the axis of the front plate 10 and the rear plate 20, and the diameter of the middle plate 40 is the same as the diameter of the front plate 10. During assembly, the smooth section 30b of the leading edge 31 of each blade 30 and the smooth section 30b of the trailing edge 32 of the blade 30 are inserted into the assembly opening of the middle plate 40, and are connected to the middle plate 40 and the blade 30 through the clamping of the assembly opening, and then the blade 30 is connected to the front plate 10 and the rear plate 20, so as to achieve the position fixation between the middle plate 40 and the front plate 10 and the rear plate 20. The middle part of the middle plate 40 also has a through hole through which the output shaft of the motor 300 passes and is fixed, so that when the motor 300 is in operation, the entire impeller 100 can be driven to rotate through the middle plate 40. The smooth section 30b of the middle plate 40 connected to the leading edge 31 and the smooth section 30b of the trailing edge 32 is less likely to deform and displace than the sawtooth section 30a provided at the leading edge 31 and the trailing edge 32, so as to improve the installation stability of the middle plate 40.
[0063] It can be understood that the middle plate 40 is usually located between the front plate 10 and the rear plate 20, that is, the middle plate 40 is also arranged close to the middle of the blade 30. Further, the total length L1 of the smooth section 30b located at the leading edge 31, and the distance between the end of the smooth section 30b close to the front plate 10 and the middle plate 40 is L3, which satisfies: 0.5L1≤L3≤L1. The above arrangement will make the smooth section 30b closer to the working area near the middle plate 40, and because the airflow near the middle plate 40 is larger, the working area of the middle part of the leading edge 31 of the blade 30 is ensured, so as to further improve the workability of the blade 30. Similarly, the smooth section 30b of the trailing edge 32 can be arranged in the same manner as the leading edge 31, so as to ensure the working area of the middle part of the leading edge 31 of the blade 30.
[0064] Reference Figure 4 In other embodiments, the center of the smooth section 30b located at the leading edge 31 is L4 from the center of the distance between the front disc 10 and the rear disc 20, and the total length L1 of the smooth section 30b located at the leading edge 31 satisfies: L4≤1 / 5L1. The above arrangement will make the smooth section 30b closer to the working area near the middle of the front disc 10 and the rear disc 20, and because the airflow near the middle of the front disc 10 and the rear disc 20 is larger, the working area in the middle of the leading edge 31 of the blade 30 is ensured, so as to further improve the workability of the blade 30. Similarly, the smooth section 30b of the trailing edge 32 can be arranged in the same manner as the leading edge 31, so as to ensure the working area in the middle of the leading edge 31 of the blade 30.
[0065] The same or similar numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of this application, it should be understood that if the terms "upper", "lower", "left", "right", etc. indicate an orientation or position relationship based on the orientation or position relationship shown in the drawings, it is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0066] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.
Claims
1. An impeller, used in a centrifugal fan, characterized in that: The impeller comprises: front plate; a rear disc, the rear disc being spaced apart from the front disc; and A plurality of blades, opposite ends of each blade are respectively connected to the front disk and the rear disk, and the plurality of blades are spaced and distributed along the circumference of the front disk and the rear disk; The blade has a leading edge and a trailing edge, wherein the leading edge is arranged toward the inner side of the rear disk, and the trailing edge is arranged toward the outer side of the rear disk, and both the leading edge and the trailing edge are provided with a sawtooth segment and a smooth segment arranged adjacent to the sawtooth segment.
2. The impeller according to claim 1, characterized in that The sawtooth segment located at the leading edge includes a first sawtooth sub-segment and a second sawtooth sub-segment, wherein the first sawtooth sub-segment is located at a side of the smooth segment of the leading edge close to the front disk, and the second sawtooth sub-segment is located at a side of the smooth segment of the leading edge close to the rear disk; The sawtooth segment located at the trailing edge includes a third sub-sawtooth segment and a fourth sub-sawtooth segment. The third sub-sawtooth segment is located at a side of the smooth segment of the trailing edge close to the front disk, and the fourth sub-sawtooth segment is located at a side of the smooth segment of the trailing edge close to the rear disk.
3. The impeller according to claim 1, characterized in that The smooth section at the leading edge extends to the middle of the leading edge.
4. The impeller according to claim 1, characterized in that: The smooth section of the leading edge and the smooth section of the trailing edge are symmetrically arranged.
5. An impeller as claimed in any one of claims 2 to 4, characterized in that The length of the smooth section at the leading edge is L1, and the total length of the blade between the front disk and the rear disk is L2, which satisfies: 0.35≤L1 / L2≤0.
65.
6. An impeller as claimed in any one of claims 2 to 4, characterized in that The impeller further comprises a middle disk, which is connected to the smooth section of the leading edge and the smooth section of the trailing edge and is located between the front disk and the trailing disk.
7. The impeller according to claim 6, characterized in that The total length of the smooth section at the front edge is L1, and the distance between one end of the smooth section close to the front disc and the middle disc is L3, satisfying: 0.5L1≤L3≤L1.
8. An impeller as claimed in any one of claims 2 to 4, characterized in that The center of the smooth section at the front edge and the center of the distance between the front disk and the rear disk is L4, and the total length L1 of the smooth section at the front edge satisfies: L4≤1 / 5L1.
9. An impeller as claimed in any one of claims 1 to 4, characterized in that The smooth segment is a straight line segment setting or an arc segment setting; And / or, the shape of the teeth of the sawtooth segment is rectangular, arc-shaped or angular.
10. A centrifugal fan, characterized in that: It comprises a volute and an impeller as claimed in any one of claims 1 to 9, wherein the volute is provided with a containing cavity and an air inlet and an air outlet respectively connected to the containing cavity, and the impeller is located in the containing cavity.
11. A range hood, characterized in that: It comprises a casing and the centrifugal fan as claimed in claim 10, wherein the centrifugal fan is installed in the casing.