Centrifugal fan impeller and fan

Abstract

The utility model discloses a centrifugal fan impeller and fan, including impeller bottom plate, impeller cover, and install and connect between the impeller bottom plate and the air wheel cover plate the circumferential interval distribution's several main wind blade, set up the air inlet in the middle of impeller cover, form the air duct between two adjacent main wind blade, the central setting of impeller bottom plate has the connecting seat, sets up the circumferential interval distribution's several second auxiliary blade in the edge accessory of the top of impeller bottom plate, its characterized in that: the bottom surface of impeller cover has the protruding several first auxiliary blade, and the circumferential interval distribution of several first auxiliary blade around the periphery of air inlet. It makes the fan of drawing in more air flow from the air inlet when rotating, improves the fan performance, and through simulation test, can improve the air flow of fan of drawing in at least 5%.

Description

Technical Field

[0001] This utility model relates to a centrifugal fan impeller and an induced draft fan. Background Technology

[0002] In centrifugal fans, induced draft fans typically use ordinary AC asynchronous motors as the drive motor, which meets basic functional requirements. Compared to DC inverter fans, they are cheaper and more reliable. However, AC asynchronous motors are affected by the power grid frequency and the number of pole pairs, resulting in a lower upper speed limit. Under certain structural space constraints, there are limited ways to increase the airflow of induced draft fans. For example, patent US6318358(B1) adds a set of negative pressure blades below the main blades of the impeller to increase the airflow. The specific structure can also be referenced in Chinese patent number 202422360533.2, entitled "A Windmill and its Application in a Blower."

[0003] Because induced draft fans are inexpensive, they generally use asynchronous motors. Due to limitations in power grid frequency, the upper speed limit of the motor is low. Under the constraints of the space structure of the induced draft fan product, it is difficult to increase the airflow of the induced draft fan. Summary of the Invention

[0004] This utility model provides a centrifugal fan impeller and an induced draft fan, which solves the technical problem of difficulty in increasing the airflow of the induced draft fan under the spatial structure limitations of the existing induced draft fan products.

[0005] The technical solution of this utility model is implemented as follows:

[0006] A centrifugal fan impeller includes an impeller base plate, an impeller cover plate, and a plurality of main air blades circumferentially spaced and installed between the impeller base plate and the impeller cover plate. An air inlet is provided in the middle of the impeller cover plate, and an air duct is formed between two adjacent main air blades. A connecting seat is provided in the center of the impeller base plate, and a plurality of second secondary blades circumferentially spaced are provided on the edge of the top of the impeller base plate. The impeller is characterized in that a plurality of first secondary blades protrude from the bottom surface of the impeller cover plate and are circumferentially spaced around the periphery of the air inlet.

[0007] Preferably, the first auxiliary blades protruding from the bottom surface of the impeller cover plate are staggered from the main wind blades that are circumferentially spaced above the top surface of the impeller cover plate.

[0008] Preferably, the number of main wind blades, first auxiliary blades, and second auxiliary blades are the same.

[0009] Preferably, a metal nut for connecting to the motor shaft is embedded in the connecting seat.

[0010] Preferably, the axial height H1 of the main blade and the axial height H2 of the first auxiliary blade have the following relationship: H2 is in the range of 8%H1 to 12%H1.

[0011] Preferably, the axial height H1 of the main blade is equal to the axial height H3 of the second blade.

[0012] Preferably, the cross-sectional shape of the first auxiliary blade is the same as that of the main wind blade, and the first auxiliary blade 22 is located in the middle of two adjacent main wind blades 3 in the circumferential direction.

[0013] Preferably, the impeller base plate, impeller cover plate, and main fan blades are all injection molded parts.

[0014] An induced draft fan includes a volute, a motor mounted outside the volute, and an impeller mounted inside the volute cavity, characterized in that: the impeller is a centrifugal fan impeller as described above, and the motor shaft extends into the inner cavity and is connected to the impeller's connecting seat.

[0015] Compared with the prior art, this utility model has the following advantages:

[0016] Effect 1: This invention features several first-stage blades protruding from the bottom surface of the impeller cover plate, with these blades circumferentially spaced around the air inlet. When the induced draft fan rotates, it draws in more airflow from the air inlet, improving fan performance; simulation tests show that it can increase the airflow of the induced draft fan by at least 5%.

[0017] Effect 2: The axial height H1 of the main blade and the axial height H2 of the first auxiliary blade have the following relationship: H2 is in the range of 8% to 12% of H1. The impeller obtains the best performance through simulation test.

[0018] Effect 3: The first set of blades protruding from the bottom surface of the impeller cover plate and the main wind blades distributed circumferentially above the top surface of the impeller cover plate are staggered and evenly distributed, so that the air at the air inlet can flow in fully, avoid the two airflows from interfering with each other and increasing the flow loss, and improve the working performance of the fan.

[0019] Other advantages of this invention are described in detail in the Embodiments section. Attached Figure Description

[0020] Figure 1 This is a perspective view of one angle of Embodiment 1 of the present invention;

[0021] Figure 2 This is a perspective view of another embodiment of the present invention;

[0022] Figure 3 This is an exploded view of Embodiment 1 of the present invention;

[0023] Figure 4 This is a front view of Embodiment 1 of the present utility model;

[0024] Figure 5 yes Figure 4 AA section view;

[0025] Figure 6 yes Figure 4 BB section view;

[0026] Figure 7 This is a perspective view of Embodiment 2 of this utility model;

[0027] Figure 8 This is a structural cross-sectional view of Embodiment 2 of this utility model. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] Example 1:

[0030] like Figures 1 to 6 As shown, this embodiment provides a centrifugal fan impeller, including an impeller base plate 1, an impeller cover plate 2, and a plurality of main fan blades 3 circumferentially spaced and installed between the impeller base plate 1 and the impeller cover plate 2. An air inlet 21 is provided in the middle of the impeller cover plate 2, and an air duct 10 is formed between two adjacent main fan blades 3. A connecting seat 11 is provided in the center of the impeller base plate 1, and a plurality of second auxiliary blades 13 circumferentially spaced and arranged on the edge of the top of the impeller base plate 1. The characteristic feature is that a plurality of first auxiliary blades 22 protrude from the bottom surface of the impeller cover plate 2, and the plurality of first auxiliary blades 22 are circumferentially spaced around the periphery of the air inlet 21.

[0031] This invention features a plurality of first sub-blades 22 protruding from the bottom surface of the impeller cover plate 2, which are circumferentially spaced around the air inlet 21. When the induced draft fan rotates, it draws in more airflow from the air inlet, improving fan performance; simulation tests show that it can increase the airflow of the induced draft fan by at least 5%.

[0032] Preferably, the first auxiliary blades 22 protruding from the bottom surface of the impeller cover plate 2 are staggered from the main air blades 3 circumferentially spaced above the top surface of the impeller cover plate 2. This staggered and even distribution of the first auxiliary blades 22 protruding from the bottom surface of the impeller cover plate 2 and the main air blades 3 circumferentially spaced above the top surface of the impeller cover plate 2 ensures sufficient airflow at the air inlet, avoids mutual interference between the two airflows causing increased flow losses, and improves the working performance of the fan.

[0033] Preferably, the connecting seat 11 is fitted with a metal nut 12 for connecting with the motor shaft, so that the connection is firm and reliable.

[0034] Preferably, the number of main wind blades 3, the number of first auxiliary blades 22 and the number of second auxiliary blades 13 are the same, the layout is reasonable and the coordination is appropriate.

[0035] Preferably, the axial height H1 of the main blade 3 and the axial height H2 of the first auxiliary blade 22 have the following relationship: H2 is in the range of 8%H1 to 12%H1, and the impeller obtains the best performance through simulation testing.

[0036] Preferably, the axial height H1 of the main blade 3 is equal to the axial height H3 of the second auxiliary blade 13.

[0037] Preferably, the cross-sectional shape of the first auxiliary blade 22 is the same as that of the main air blade 3, and the first auxiliary blade 22 is located in the middle of two adjacent main air blades 3 in the circumferential direction, so as to avoid the two airflows interfering with each other and causing increased flow loss, thereby improving the working performance of the fan.

[0038] Preferably, the impeller base plate, impeller cover plate, and main fan blades are all injection molded parts, which are easy to manufacture and have low cost.

[0039] Preferably, a number of main air blades 3 have protruding positioning posts 31 below them, and a number of positioning holes 23 are provided on the impeller base plate 1. The positioning posts 31 are nested in the positioning holes 23 and the main air blades 3 are welded to the impeller base plate 1 using ultrasonic welding technology.

[0040] Example 2:

[0041] like Figure 7 and Figure 8 As shown, this embodiment provides an induced draft fan, including a volute 5, a motor 6 installed outside the volute 5, and an impeller 100 installed in the inner cavity 51 of the volute 5. The impeller 100 is a centrifugal fan impeller as described in Embodiment 1. The shaft of the motor 6 extends into the inner cavity 51 and is connected to the connecting seat 11 of the impeller 100. The motor 6 is an AC motor.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A centrifugal fan impeller, comprising an impeller base plate (1), an impeller cover plate (2), and a plurality of main fan blades (3) circumferentially spaced and installed between the impeller base plate (1) and the impeller cover plate (2), wherein an air inlet (21) is provided in the middle of the impeller cover plate (2), an air duct (10) is formed between two adjacent main fan blades (3), a connecting seat (11) is provided in the center of the impeller base plate (1), and a plurality of second auxiliary blades (13) circumferentially spaced and attached to the edge of the top of the impeller base plate (1), characterized in that: Several first-stage blades (22) protrude from the bottom surface of the impeller cover plate (2), and the several first-stage blades (22) are distributed circumferentially around the air inlet (21).

2. The centrifugal fan impeller according to claim 1, characterized in that: The first auxiliary blades (22) protruding from the bottom surface of the impeller cover plate (2) are staggered from the main wind blades (3) that are circumferentially spaced above the top surface of the impeller cover plate (2).

3. A centrifugal fan impeller according to claim 2, characterized in that: The number of main wind blades (3), first auxiliary blades (22) and second auxiliary blades (13) is the same.

4. A centrifugal fan impeller according to claim 2, characterized in that: The connecting seat (11) contains a metal nut (12) for connecting to the motor shaft.

5. A centrifugal fan impeller according to claim 1, 2, 3, or 4, characterized in that: The axial height H1 of the main blade (3) and the axial height H2 of the first auxiliary blade (22) have the following relationship: H2 is in the range of 8%H1 to 12%H1.

6. A centrifugal fan impeller according to claim 1, 2, 3, or 4, characterized in that: The axial height H1 of the main blade (3) is equal to the axial height H3 of the second auxiliary blade (13).

7. A centrifugal fan impeller according to claim 6, characterized in that: The cross-sectional shape of the first auxiliary blade (22) is the same as that of the main wind blade (3), and the first auxiliary blade (22) is located in the middle of two adjacent main wind blades (3) in the circumferential direction.

8. A centrifugal fan impeller according to claim 5, characterized in that: The impeller base plate (1), impeller cover plate (2) and main air blades (3) are all injection molded parts.

9. An induced draft fan, comprising a volute (5), a motor (6) mounted outside the volute (5), and an impeller (100) mounted in the inner cavity (51) of the volute (5), characterized in that: The impeller (100) is a centrifugal fan impeller according to any one of claims 1 to 8. The shaft of the motor (6) extends into the inner cavity (51) and is connected to the connecting seat (11) of the impeller (100). The motor (6) is an AC motor.

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