CN113309714B - Multi-wing centrifugal fans and household appliances - Google Patents

Abstract

The invention discloses a multi-wing centrifugal fan and a household appliance. The multipurpose centrifugal fan includes: the impeller assembly comprises an impeller body and a hub, wherein the hub comprises a first side surface and a second side surface which are opposite to each other, the impeller body comprises a first section and a second section, the first section is connected to the first side surface, the second section is connected to the second side surface, and the diameter of the first section and the diameter of the second section are gradually increased along the direction away from the hub; the volute comprises a volute body and a volute tongue, the impeller assembly is arranged in the volute body, and the volute tongue is spaced from the impeller assembly; and the motor is connected with the hub and used for driving the impeller assembly to rotate. According to the multi-wing centrifugal fan, noise in the area close to the hub is reduced, and the volute tongue gap in the area far from the hub is reduced by increasing the volute tongue gap in the area close to the hub, so that work efficiency in the area far from the hub is increased.

Description

Multi-wing centrifugal fans and household appliances

Technical field

The present invention relates to the technical field of fans, and in particular to a multi-wing centrifugal fan and household appliances.

Background technique

Multi-wing centrifugal fans are widely used in industrial equipment, such as range hoods, due to their advantages of large air volume, low noise, and low cost.

However, in the existing technology, the airflow is unbalanced in the axial direction of the multi-blade centrifugal fan, which makes the multi-blade centrifugal fan noisy during use. However, the usual method of reducing the noise of the multi-blade centrifugal fan will have a negative impact on the multi-blade centrifugal fan. Wing centrifugal fan has a greater impact on the working efficiency.

Contents of the invention

The embodiment of the present invention provides a multi-blade centrifugal fan and household appliances.

The multi-blade centrifugal fan according to the embodiment of the present invention includes an impeller assembly, including an impeller body and a hub. The hub includes a first side and a second side that are opposite to each other. The impeller body includes a first section and a second section. The first section is connected to the first side, the second section is connected to the second side, and the diameter of the first section and the diameter of the second section gradually increase in the direction away from the hub. ;

A volute includes a volute body and a volute tongue, the impeller assembly is installed in the volute body, and the volute tongue is spaced apart from the impeller assembly;

A motor is connected to the hub and used to drive the impeller assembly to rotate.

In some embodiments, the motor is located on the side where the second side is located, the length of the first section is B1, the length of the second section is B2, B1>B2 and B1, B2>0 .

In some embodiments, the angle between the outer diameter of the first section and the axial direction of the first section is a1, and the angle between the outer diameter of the second section and the axial direction of the second section is a1. The angle is a2, a1<a2, a1≥0° and 0°<a2<10°.

In some embodiments, the diameters of both ends of the impeller body are equal.

In some embodiments, the maximum outer diameter of the impeller assembly is D1, the length of the second section is B2, 0.4*D1≤B2≤D1 and D1, B2>0.

In some embodiments, the radius of the connection between the volute tongue and the volute body is the volute radius, and the volute radius gradually increases in the direction approaching the hub.

In some embodiments, the radius of the volute near the motor is R1, the radius of the volute away from the motor is R2, and the radius of the volute close to the hub is R2. The shell radius is R3, R1<R2<R3 and R1, R2, R3>0.

In some embodiments, the tongue depth gradually increases away from the hub.

In some embodiments, the impeller assembly further includes reinforcing ribs installed on the impeller body.

The household appliance according to the embodiment of the present invention includes the multi-blade centrifugal fan described in the above embodiment.

In the multi-blade centrifugal fan and household appliances according to the embodiment of the present invention, the diameter of the first section and the diameter of the second section are gradually increased in the direction away from the hub, so that the gap between the impeller body and the volute tongue is arranged in the direction closer to the hub. Gradually increase the setting, so that the volute tongue clearance in the area close to the hub becomes larger and the noise becomes smaller, and the volute tongue clearance in the area far from the hub becomes smaller, and the work efficiency increases.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of the drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

Figure 1 is a schematic structural diagram of a multi-blade centrifugal fan according to an embodiment of the present invention;

Figure 2 is another structural schematic diagram of the multi-blade centrifugal fan according to the embodiment of the present invention;

Figure 3 is a schematic structural diagram of the impeller assembly according to the embodiment of the present invention;

Figure 4 is an enlarged view of point A in Figure 3;

Figure 5 is a rear view of the volute of the multi-blade centrifugal fan according to the embodiment of the present invention;

Figure 6 is a cross-sectional view at B-B in Figure 5;

Figure 7 is a cross-sectional view at B-B in Figure 5;

Figure 8 is a cross-sectional view at C-C in Figure 5;

Figure 9 is a cross-sectional view at D-D in Figure 5;

Main features and symbols:

Multi-blade centrifugal fan 100, impeller assembly 10, impeller body 11, first section 11a, second section 11b, hub 12, first side 121, second side 122, reinforcing rib 13, volute 20, volute body 21, Snail tongue 22, motor 30.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the embodiments of the present invention and cannot be understood as limiting the embodiments of the present invention.

In the embodiment of the present invention, the first feature being "above" or "below" the second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in direct contact with each other. Additional characteristic contacts between them. Furthermore, the terms "above", "above" and "above" a first feature on a second feature include the first feature being directly above and diagonally above the second feature, or simply mean that the first feature is higher in level than the second feature. “Below”, “under” and “under” the first feature is the second feature includes the first feature being directly below and diagonally below the second feature, or simply means that the first feature is less horizontally than the second feature.

The following disclosure provides many different embodiments or examples of different structures for implementing embodiments of the invention. In order to simplify the disclosure of embodiments of the invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the invention. Embodiments of the present invention may repeat reference numbers and/or reference letters in different examples, such repetition being for purposes of simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, embodiments of the present invention provide examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Referring to FIGS. 1 to 3 , the multi-blade centrifugal fan 100 according to the embodiment of the present invention includes an impeller assembly 10 , a volute 20 and a motor 30 . The impeller assembly 10 includes an impeller body 11 and a hub 12. The hub 12 includes a first side 121 and a second side 122 that are opposite to each other. The impeller body 11 includes a first section 11a and a second section 11b. The first section 11a is connected to the first side. 121. The second section 11b is connected to the second side 122. The diameter d1 of the first section 11a and the diameter d2 of the second section 11b gradually increase in the direction away from the hub 12. The volute 20 includes a volute body 21 and a volute tongue 22 . The impeller assembly 10 is installed in the volute body 21 . The volute tongue 22 is spaced apart from the impeller assembly 10 . The motor 30 is connected to the hub 12 for driving the impeller assembly 10 to rotate.

The power area of the multi-blade centrifugal fan 100 is mainly concentrated near the hub 12. The airflow velocity in the power area is larger, and the noise generated by the volute tongue 22 is larger. The airflow velocity in the area away from the hub 12 is smaller, the noise is smaller, but the power is generated. less.

In the embodiment of the present invention, the diameter d1 of the first section 11a and the diameter d2 of the second section 11b are gradually increased in the direction away from the hub 12, so that the gap between the impeller body 11 and the volute tongue 22 is arranged in the direction closer to the hub 12. Gradually increase the setting, so that the gap between the volute tongues 22 in the area close to the hub 12 becomes larger and the noise becomes smaller, and the gap between the volute tongues 22 in the area far away from the hub 12 becomes smaller and the work efficiency increases.

Specifically, the multi-blade centrifugal fan 100 may be a left-hand centrifugal fan or a right-hand centrifugal fan. Viewed from the side of the motor, if the impeller rotates clockwise, it is called a right-hand centrifugal fan, and if it rotates counterclockwise, it is called a left-hand centrifugal fan. In some embodiments, the multi-blade centrifugal fan 100 may be a double-suction multi-blade centrifugal fan. The double-suction multi-blade centrifugal fan includes two volutes 20 and two impeller assemblies 10 . The impeller assemblies 10 correspond to the volutes 20 one-to-one. . Preferably, the double-suction multi-blade centrifugal fan includes a motor 30 , which is disposed between the two volutes 20 and the two impeller assemblies 10 . In this way, the motor 30 can supply energy to the two impeller assemblies 10 at the same time, effectively saving costs and reducing the size of the double-suction multi-blade centrifugal fan. It is worth mentioning that the double-suction multi-wing centrifugal fan has four air flow inlets and two air flow outlets, that is, there are two air flow inlets at both ends of the impeller assembly 10. There are two impeller assemblies 10, which means there are four air flow inlets. . It is worth noting that the two airflow inlets of the double-suction multi-wing centrifugal fan close to the motor 30 are blocked by the motor 30. Therefore, the two airflow inlets of the double-suction multi-wing centrifugal fan close to the motor 30 are smaller than those of the double-suction multi-wing centrifugal fan. The air flow at the two air flow suction inlets away from the motor 30 is small. In addition, the two airflow inlets of the double-suction multi-wing centrifugal fan close to the motor 30 can also be used to ventilate and dissipate heat for the motor 30, thereby reducing the temperature of the motor 30.

The first section 11a can be connected to the periphery of the first side 121, that is, the diameter of the end of the first section 11a close to the first side 121 is the same as the diameter of the first side 121; the first section 11a can also be connected to the middle part of the first side 121. Connection, that is, the diameter of one end of the first section 11a close to the first side 121 is smaller than the diameter of the first side 121; the first section 11a can also be partially connected to the periphery of the first side 121, and the other part is connected to the middle of the first side 121 , that is, the diameter of the end of the first section 11a close to the first side 121 is smaller than the diameter of the first side 121 but the first section 11a is tangent to the periphery of the first side 121 , and the connection position between the first section 11a and the first side 121 There are many, and there are no specific restrictions here.

The second section 11b can be connected to the periphery of the second side 122, that is, the diameter of the end of the second section 11b close to the second side 122 is the same as the diameter of the second side 122; the second section 11b can also be connected to the middle part of the second side 122. Connection, that is, the diameter of one end of the second section 11b close to the second side 122 is smaller than the diameter of the second side 122; the second section 11b can also be partially connected to the periphery of the second side 122, and the other part is connected to the middle of the second side 122 , that is, the diameter of the end of the second section 11b close to the second side 122 is smaller than the diameter of the second side 122 but the second section 11b is tangent to the periphery of the second side 122. The connection position between the second section 11b and the second side 122 There are many, and there are no specific limitations here.

It is worth noting that the diameter of the end of the first section 11a close to the first side 121 can be the same as the diameter of the end of the second section 11b close to the second side 122, and the diameter of the end of the first section 11a close to the first side 121 can also be the same. The diameter of one end of the second section 11b close to the second side 122 is different. Preferably, the diameter of the first section 11a close to the first side 121 and the diameter of the second section 11b close to the second side 122 are the same, and one end of the first section 11a close to the first side 121 is connected to the periphery of the first side 121. One end of the second section 11b close to the second side 122 is connected to the periphery of the second side 122 .

The diameter d1 of the first section 11a can increase equidistantly in the direction away from the hub 12, that is, the first section 11a is in a straight line with the outer contour of the same plane in the axial direction; the diameter d1 of the first section 11a can increase along the direction away from the hub 12. The direction can also increase unequally, that is, the outer contour of the first section 11a and the axial direction can be in the same plane as a concave arc, a convex arc, a wave shape, etc. The first section 11a and the axial direction are located in the same plane. There are many shapes of the outer contour of the plane, which are not specifically limited here.

The diameter d2 of the second section 11b can increase equidistantly in the direction away from the hub 12, that is, the second section 11b is in a straight line with the outer contour of the same plane in the axial direction; the diameter d2 of the second section 11b can increase along the direction away from the hub 12. The direction can also increase unequally, that is, the outer contour of the second section 11b located on the same plane as the axial direction can be in the shape of a concave arc, a convex arc, a wave shape, etc. The second section 11b is located on the same plane as the axial direction. There are many shapes of the outer contour of the plane, which are not specifically limited here.

The shape of the outer contour of the first section 11a located on the same plane as the axial direction may be the same as or different from the shape of the outer contour of the second section 11b located on the same plane as the axial direction, and is not specifically limited here.

The first section 11a includes a plurality of first fan blades. The number of the first fan blades can be 10, 20, 30, 40, 50, 100, etc. The specific number can be adjusted as needed and is not mentioned here. Make specific limitations. The first fan blade can be a forward fan blade, a backward fan blade, or a straight fan blade, which is not specifically limited here.

The second section 11b includes a plurality of second fan blades. The number of the second fan blades can be 10, 20, 30, 40, 50, 100, etc. The specific number can be adjusted as needed and is not mentioned here. Make specific limitations. The number of the second fan blades may be the same as the number of the first fan blades, or may be different.

There are many shapes of the volute body 21, which can be in the shape of a cylinder, a truncated cone, etc. The shape of the volute body 21 is adapted to the shape of the impeller body 11, and is not specifically limited here. The volute body 21 may include a volute plate, side plates, legs, etc., and the volute body 21 has a supporting and protective role.

The volute tongue 22 is used to prevent part of the gas from circulating in the volute 20 . The volute tongue 22 is spaced apart from the impeller assembly 10 to prevent the volute tongue 22 from impeding the movement of the impeller assembly 10 .

There are many ways to connect the motor 30 to the hub 12. For example, the hub 12 is provided with a through hole, and the output shaft of the motor 30 fits with the through hole; another example is that the output shaft of the motor 30 is snap-fitted with the hub 12; another example is that the motor 30 The output shaft is indirectly connected to the hub 12 by connecting to the impeller body 11 .

It should be noted that the above-mentioned examples and specific numerical values are for convenience of illustrating the implementation of the present invention and should not be understood as limiting the scope of the present invention.

In some embodiments, please refer to Figures 1 to 3, the motor 30 is located on the side where the second side 122 is located, the length of the first section 11a is B1, the length of the second section 11b is B2, B1>B2 and B1 , B2>0. Both ends along the axial direction of the impeller body 11 are air inlets of the impeller assembly 10 , that is, the end of the first section 11 a away from the hub 12 and the end of the second section 11 b away from the hub 12 are both air inlets. The motor 30 is located on the side where the second side 122 is located, which will affect the air intake of the air inlet of the second section 11b, so that the air intake volume of the second section 11b is compared with the air intake volume of the first section 11a without fan obstruction. should be small, so that the main pressurization area of the entire impeller body 11 is not located in the middle of the impeller body 11 , but is located closer to the motor 30 than the middle of the impeller body 11 . Setting B1>B2 means that the hub 12 is placed in the main pressurizing area of the impeller body 11, so that the diameter d2 of the first section 11a and the second section 11b at the main pressurizing area is smaller, that is, the diameter d2 at the main pressurizing area is smaller. The clearance between the volute tongues 22 of the first section 11a and the second section 11b is large, which effectively reduces the noise in the main pressurization area.

It is worth noting that the length B1 of the first section 11a means the approximate length of the first section 11a along the axial direction of the impeller body 11, that is, the lengths of the first section 11a at different positions along the axial direction of the impeller body 11 are different. They must all be equal, and B1 can be the approximate length of the first section 11a along the axial direction of the impeller body 11 . The length B2 of the second section 11b means the approximate length of the second section 11b along the axial direction of the impeller body 11, that is, the lengths of the second section 11b in the axial direction of the impeller body 11 at different positions are not necessarily the same, B2 Just take the approximate length of the second section 11b along the axial direction of the impeller body 11 .

In some embodiments, please refer to Figures 3 and 4. The angle between the outer diameter of the first section 11a and the axial direction of the first section 11a is a1, and the angle between the outer diameter of the second section 11b and the axial direction of the second section 11b is a1. The angle in the axial direction is a2, a1<a2, a1≥0° and 0°<a2<10°. If the angle a1 or a2 is too large, the diameter d1 of the first section 11a or the diameter d2 of the second section 11b located in the main work area will be too small, thereby affecting the air volume performance of the multi-blade centrifugal fan 100. Set a1<a2, a1≥0° and 0°<a2<10° so that the impeller body 11 can be tilted at a certain angle to ensure that the outer diameter of the main power area of the impeller body 11 is smaller than the outer diameter away from the hub 12, thus increasing the The clearance between the volute tongues 22 in the main work area reduces the noise in the main work area.

There are many angles of a1 and a2. a1 can be 0°, 3°, 5°, 9°, 9.5°, etc., and a2 can be 0.5°, 2°, 4°, 6°, 8°, 9.5°, etc. The angle is not specifically limited here.

It is worth noting that the outer diameter of the first section 11a means the outer contour of the first section 11a located on the same plane as the axial direction. The outer contour can be a straight line or a curve. When the outer contour is When it is a curve, the outer diameter of the first segment 11a can be obtained by connecting the starting point and the end point of the outer contour, or the outer diameter of the first segment 11a can be obtained by connecting the starting point and the midpoint of the outer contour. A tangent line somewhere on the outer contour is used as the outer diameter of the first section 11a. The outer diameter of the first section 11a can be roughly the same as the extension direction of the outer contour, and there is no specific limitation here.

The outer diameter of the second section 11b means the outer contour of the second section 11b located on the same plane as the axial direction. The outer contour can be a straight line or a curve. When the outer contour is a curve, it can be The outer diameter of the second segment 11b can be obtained by connecting the starting point and the end point of the outer contour. The outer diameter of the second segment 11b can also be obtained by connecting the starting point and the midpoint of the outer contour. You can also obtain the outer diameter of the second segment 11b by connecting a certain point of the outer contour. The tangent line is used as the outer diameter of the second section 11b. The outer diameter of the second section 11b can be substantially the same as the extension direction of the outer contour, and there is no specific limitation here.

In some embodiments, please refer to FIGS. 1 to 3 , the diameters of both ends of the impeller body 11 are equal, that is, the diameter of the end of the first section 11 a away from the hub 12 is equal to the diameter of the end of the second section 11 b away from the hub 12 . With this arrangement, the volute 20 can be configured as a cylinder that is convenient for production, thereby facilitating the production of the multi-blade centrifugal fan 100. Preferably, the diameter d1 of the first section 11a close to the hub 12 is the same as the diameter d2 of the second section 11b close to the hub 12, and the diameter d1 of the first section 11a away from the hub 12 is also the same as the diameter d2 of the second section 11b away from the hub 12. Such an arrangement not only facilitates production, but also improves the working efficiency of the motor.

In some embodiments, please refer to FIG. 3 , the maximum outer diameter of the impeller assembly 10 is D1, the length of the second section 11b is B2, 0.4*D1≤B2≤D1 and D1, B2>0. If the length of the second section 11b is too small, the supercharging effect of the second section 11b will be poor and it will not be able to perform a good supercharging function. If the length of the second section 11b is too large, a larger vortex will be formed. area may produce reverse flow, therefore, it is set in such a way that the length of the second section 11b ensures the supercharging effect while taking into account the supercharging efficiency. In the same way, the length of the first section 11a cannot be too large or too small, and the length of B1 can also be within the range of 0.4*D1 to D1.

In some embodiments, please refer to FIGS. 2 and 5 , the radius of the connection between the volute tongue 22 and the volute body 21 is the radius of the volute 20 , and the radius of the volute 20 gradually increases in the direction approaching the hub 12 . The larger the radius of the volute tongue 22, the smaller the turning point of the airflow to the volute tongue 22, so that the noise of the airflow to the volute tongue 22 is smaller. The radius of the volute 20 is gradually increased in the direction close to the hub 12, so that it is closer to the hub. Noise reduction at position 12.

In some embodiments, please refer to Figure 5 and Figures 7 to 9 , the radius of the volute 20 near the motor 30 is R1, and the radius of the volute 20 away from the motor 30 is R2. The radius of the volute 20 close to the hub 12 is R3, R1<R2<R3 and R1, R2, R3>0. In the multi-wing centrifugal fan 100, the hub 12 is located in the main pressurization area of the multi-wing centrifugal fan 100, so the air flow at the hub 12 is larger, and the air inlet far away from the motor 30 is not blocked by the fan, and the air inlet closer to the motor 30 is not blocked by the fan. The airflow at the tuyere is large, so the airflow where the volute 20 is close to the motor 30, the airflow where the volute 20 is far away from the fan, and the airflow where the volute 20 is close to the hub 12 increase in sequence, so that the volute 20 is close to the motor 30. The radius R1, the radius R2 of the volute 20 where the volute 20 is away from the motor 30, and the radius R3 of the volute 20 where the volute 20 is close to the hub 12 are sequentially increased to effectively reduce the noise of the multi-wing centrifugal fan 100.

In some embodiments, see FIG. 6 , the tongue depth gradually increases away from the hub 12 . The depth of the volute tongue is closely related to the noise of the multi-blade centrifugal fan 100. Generally, if the volute tongue depth is large, the noise will be higher but the aerodynamic performance is better. On the contrary, the noise will be smaller. The depth β1 of the volute tongue close to the hub 12 is small, which effectively reduces the noise there, while the depth β2 of the volute tongue far away from the hub 12 is large, which effectively improves the aerodynamic performance there.

It is worth noting that the smaller depth β1 of the volute tongue close to the hub 12 means that the position close to the hub 12 is a shallow tongue, and the larger depth β2 of the volute tongue at the position far away from the hub 12 means that the position far away from the hub 12 is Deep tongue. The standard of deep tongue and shallow tongue is not fixed, as long as the depth of the volute tongue is larger at the position close to the hub 12 than at the position far away from the hub 12.

It is worth adding that the depth of the volute tongue is the angle between the straight line passing through the center of the impeller assembly 10 and the straight line passing through the center of the volute tongue 22 and the center of the impeller assembly 10. The straight line passing through the center of the impeller assembly 10 is usually along the vertical axis. A straight line extending vertically or horizontally. The positive direction of the tongue depth is the opposite direction of the rotation direction of the impeller assembly 10, that is, based on the straight line passing through the center of the circle of the impeller assembly 10, the more volute tongues 22 extend in the opposite direction of the rotation direction of the impeller assembly 10, the more volute tongues 22 The greater the depth, the vice versa.

In some embodiments, please refer to FIG. 2 and FIG. 3 , the impeller assembly 10 further includes reinforcing ribs 13 , and the reinforcing ribs 13 are installed on the impeller body 11 . The reinforcing ribs 13 are used to fix the impeller body 11 and enhance the structural stability of the impeller body 11 . The reinforcing ribs 13 may extend along the circumferential direction of the impeller body 11 , or may extend at a certain angle with the circumferential direction of the impeller body 11 , for example, the reinforcing ribs 13 may extend at an angle of 5° or 10° with the circumferential direction of the impeller body 11 . , 15°, 20°, 30°, 40° and other angles, there are no specific restrictions here.

The impeller assembly 10 may include one reinforcing rib 13 or multiple reinforcing ribs 13 , such as 2, 3, 4, etc. The extending directions of the multiple reinforcing ribs 13 may be different. The extending directions of the multiple reinforcing ribs 13 It can also be the same. The plurality of reinforcing ribs 13 can intersect or be spaced apart from each other, as long as the reinforcing ribs 13 can play a role in strengthening the structural stability of the impeller body 11, and there is no specific limit here.

In the illustrated embodiment, since the first section 11a is longer than the second section 11b, the reinforcing rib 13 is connected to the circumferential side surface of the first section 11a at 360 degrees in the middle of the first section 11a along the circumferential direction of the first section 11a. , on the one hand, the structural strength of the first section 11a can be ensured; on the other hand, in the axial and radial directions, the reinforcing ribs 13 will not cause additional vibration to the rotational stability of the first section 11a.

The embodiment of the present invention also discloses a household appliance. Specifically, household appliances include but are not limited to appliances with oil fume exhaust power supply, such as oil fume equipment, integrated stoves, and appliances with multi-wing centrifugal fans 100 such as hair dryers and vacuum cleaners. Take a household appliance as a cooking fume device as an example to illustrate. The household appliance may be an upper-row kitchen equipment, a lower-row kitchen equipment, or a side-row kitchen equipment, which is not specifically limited here.

Specifically, the household appliance includes a multi-wing centrifugal fan 100. The household appliance also includes but is not limited to a box, a deflector, a check valve and other components. The deflector, the multi-wing centrifugal fan 100 and the check valve are all installed on On the box, the oil fume enters the box through the deflector, and the multi-wing centrifugal fan 100 installed in the box works. The oil fume is sucked into the multi-wing centrifugal fan 100 under the centrifugal force of the multi-wing centrifugal fan 100 and flows from the multi-wing centrifugal fan 100. The air flow outlet is discharged into the check valve, and the check valve prevents the oil fume from flowing back into the multi-wing centrifugal fan 100, thereby realizing the discharge of the oil fume. It can be understood that a check valve refers to a valve whose opening and closing parts are circular valve discs and rely on their own weight and medium pressure to act to block the reverse flow of the medium. Check valves can be lift check valves and swing check valves.

In the description of this specification, reference to the description of the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" is intended to be in conjunction with the described implementation. A specific feature, structure, material, or characteristic described in a manner or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are illustrative and should not be construed as limitations of the present invention. Those of ordinary skill in the art can make modifications to the above-mentioned embodiments within the scope of the present invention. The embodiments are subject to changes, modifications, substitutions and variations.

Claims (8)

1. A multi-wing centrifugal fan, characterized in that it includes: The impeller assembly includes an impeller body and a hub. The hub includes a first side and a second side that are opposite to each other. The impeller body includes a first section and a second section, and the first section is connected to the first side, The second section is connected to the second side, and the diameter of the first section and the diameter of the second section gradually increase in a direction away from the hub; A volute includes a volute body and a volute tongue, the impeller assembly is installed in the volute body, and the volute tongue is spaced apart from the impeller assembly; A motor, connected to the hub, used to drive the impeller assembly to rotate; The radius of the volute where the volute is close to the motor is R1, the radius of the volute where the volute is away from the motor is R2, and the radius of the volute where the volute is close to the hub is R3, R1< R2<R3 and R1, R2, R3>0; The maximum outer diameter of the impeller assembly is D1, the length of the second section is B2, 0.4*D1≤B2≤D1 and D1, B2>0. 2. The multi-blade centrifugal fan according to claim 1, characterized in that the motor is located on the side where the second side is located, the length of the first section is B1, and the length of the second section is B1. B2, B1>B2 and B1, B2>0. 3. The multi-blade centrifugal fan according to claim 2, wherein the angle between the outer diameter of the first section and the axial direction of the first section is a1, and the outer diameter of the second section The angle with the axial direction of the second section is a2, a1<a2, a1≥0° and 0°<a2<10°. 4. The multi-blade centrifugal fan according to claim 1, wherein the diameters of both ends of the impeller body are equal. 5. The multi-blade centrifugal fan according to claim 1, wherein the radius of the connection between the volute tongue and the volute body is the volute radius, and the volute radius is along the direction close to the hub. gradually increase. 6. The multi-blade centrifugal fan according to claim 1, wherein the depth of the volute tongue gradually increases in a direction away from the hub. 7. The multi-blade centrifugal fan according to claim 1, wherein the impeller assembly further includes reinforcing ribs, and the reinforcing ribs are installed on the impeller body. 8. A household appliance, characterized by comprising the multi-blade centrifugal fan according to any one of claims 1 to 7.