Axial flow fan and air conditioner

Abstract

The present invention discloses an axial flow fan wheel and an air conditioner, wherein the axial flow fan wheel comprises a hub and a plurality of fan blades arranged on the hub, wherein the blade edge of the fan blade comprises a root edge, a front blade edge, a top blade edge and a rear blade edge connected in sequence from beginning to end, and at the same circumferential position of the fan blade, the circumferential span from the front blade edge to the rear blade edge is D0, and the circumferential span from the dividing strip connecting the root edge and the top blade edge to the front blade edge is D1, and D1 / D0∈[0.2, 0.4]; and at this circumferential position, the thickness of the fan blade at the dividing strip position is greater than the thickness at other positions, and the thickness of the rear blade edge is less than the thickness of the front blade edge. The axial flow fan wheel of the present invention can reduce the turbulence generated on the fan blade, thereby reducing the turbulent noise generated by the fan blade.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to an axial flow fan wheel and an air conditioner. Background Art

[0002] Axial flow fans are often used in household appliances or air conditioners as ventilation devices. When the axial flow fan rotates, it drives the air around it to rotate to form an airflow, and drives the airflow to blow out along the axial direction of the axial flow fan. The thickness of the blades of a conventional axial flow fan is basically the same at each position on the same circumference. When the airflow flows from the front edge of the fan blade to the rear edge of the fan blade, the airflow separates before reaching the rear edge, causing the airflow to become turbulent near the rear edge of the fan blade, generating a large turbulent noise. Summary of the invention

[0003] The main purpose of the present invention is to provide an axial flow wind wheel, aiming to reduce the turbulence generated on the wind blades, and further reduce the turbulence noise generated by the wind blades.

[0004] To achieve the above-mentioned purpose, the present invention proposes an axial flow wind wheel and an air conditioner including the axial flow wind wheel, the axial flow wind wheel includes a hub and a plurality of fan blades arranged on the hub, the blade edges of the fan blades include a blade root edge, a front blade edge, a blade top edge and a rear blade edge connected in sequence from beginning to end, at the same circumferential position of the fan blade, the circumferential span from the front blade edge to the rear blade edge is D0, the circumferential span from the dividing strip connecting the blade root edge and the blade top edge to the front blade edge is D1, D1 / D0∈[0.2,0.4]; and at this circumferential position, the thickness of the fan blade at the dividing strip position is greater than the thickness at other positions, and the thickness of the rear blade edge is less than the thickness of the front blade edge.

[0005] Preferably, the dividing strip separates the fan blade into a front blade portion and a rear blade portion, and at the same circumferential position of the fan blade, the thickness of the front blade portion gradually decreases from the dividing strip to the front blade edge, and the thickness of the rear blade portion gradually decreases from the dividing strip to the rear blade edge.

[0006] Preferably, the thickness of the fan blade at the position of the dividing strip is H0, the thickness of the front blade edge is H1, the thickness of the rear blade edge is H2, and at the same circumferential position of the fan blade, H0-H1∈[0.3mm, 1.5mm], H0-H2∈[2.5mm, 5mm].

[0007] Preferably, H0∈[4.5mm, 7.6mm]; H1∈[3.0mm, 7.3mm]; H2∈[1.7mm, 2.5mm].

[0008] Preferably, at the same radial position of the fan blade, the thickness of the fan blade gradually decreases from the blade root edge to the blade top edge.

[0009] Preferably, at the same circumferential position of the fan blade, the angle formed by the blade chord line connecting the front blade edge and the rear blade edge and the rotation plane of the axial flow wind wheel is α, and α is gradually reduced in the radial direction of the fan blade.

[0010] Preferably, α∈[20°, 30°].

[0011] Preferably, α∈[20°, 28°].

[0012] Preferably, the radius of the ring where the blade top edge is located is R0, and the radius of the ring where any blade chord line is located is R m The radius coefficient of the ring where the blade chord line is located is k, k=R m / R0,R m ∈[0, R0]: when k∈[0, 0.1], α=28-30k; when k∈(0.1, 0.4], α=26-10k; when k∈(0.4, 1], α=23.3-3.3k.

[0013] The technical solution of the present invention is to provide a dividing strip connecting the root edge and the top edge of the wind blade on the wind blade, and the ratio of the circumferential span from the dividing strip to the front blade edge to the circumferential span from the front blade edge to the rear blade edge is D1 / D0∈[0.2, 0.4], and at this circumferential position, the thickness of the wind blade at the dividing strip is greater than the thickness at other positions, and the thickness of the rear blade edge is less than the thickness of the front blade edge, so that the maximum thickness position of the wind blade appears on the dividing strip, and the blade surface of the wind blade is raised at the position where the dividing strip is located relative to other positions.

[0014] When the axial flow wind wheel is working, the front blade edge intercepts the airflow forward, and the airflow blows through the blade surface of the wind blade through the front blade edge and flows backward. The airflow first flows to the dividing strip. Affected by the raised slope of the dividing strip, the airflow has a tendency to flow "close" to the blade surface of the wind blade behind the dividing strip. After the airflow flows through the dividing strip, the airflow continues to move backward along the blade surface of the wind blade located behind the dividing strip, thereby effectively pushing the airflow backward at the separation point of the blade surface, thereby reducing the generation of turbulence and achieving the effect of reducing turbulent noise. It can be seen that, compared with conventional axial flow wind wheels, the axial flow wind wheel of the present invention can effectively push the airflow backward at the separation point of the blade surface, thereby reducing the turbulence generated on the wind blade, and thereby reducing the turbulent noise generated by the wind blade.

[0015] Furthermore, since the thickness of the rear blade edge is smaller than that of the front blade edge, on the one hand, the front blade edge can have better strength and can withstand the impact of airflow with higher wind speed; on the other hand, the rear blade edge can have a better wake, which can effectively improve the wake flow on the rear side of the wind blade and reduce the wake noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention 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 invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0017] Figure 1 A schematic structural diagram of an embodiment of an air-conditioning outdoor unit of the present invention;

[0018] Figure 2 It is a structural schematic diagram of an embodiment of an axial flow wind wheel of the present invention;

[0019] Figure 3 for Figure 2 Sectional view along line II;

[0020] Figure 4 for Figure 2 Schematic diagram of part of the structure of the central axial flow wind wheel;

[0021] Figure 5 for Figure 4 On the fan blade, one of the R m A schematic diagram of a wind blade cross section obtained by intercepting the circumference of the radius;

[0022] Figure 6 for Figure 4 On the wind blade, another R m A schematic diagram of a wind blade cross section obtained by intercepting the circumference of the radius;

[0023] Figure 7-A It is a schematic diagram of airflow flowing on the blade surface of a conventional axial flow wind wheel blade;

[0024] Figure 7-B It is a schematic diagram of airflow flowing on the blade surface of the axial flow wind wheel blade of the present invention;

[0025] Figure 8 for Figure 2 A schematic diagram of another part of the structure of the central axial flow wind wheel;

[0026] Fig. 9 for Figure 8 Different R m A comparative schematic diagram of the cross section of a wind blade obtained by intercepting the circumference of the radius;

[0027] Fig.10 The schematic diagram of the change in radial direction of the angle formed by the blade chord line of the axial flow wind wheel of the utility model and the rotation plane of the axial flow wind wheel;

[0028] Fig.11 This is a speed-air volume comparison test diagram of the axial flow wind wheel of the present invention and the conventional axial flow wind wheel;

[0029] Fig.12 This is a wind volume-noise comparison test diagram between the axial flow wind wheel of the present invention and a conventional axial flow wind wheel.

[0030] Description of Figure Numbers:

[0031]

[0032] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them, and the technical solutions must be within the scope of protection required. When the combination is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] The present invention provides an axial flow wind wheel and an air conditioner, wherein the air conditioner may be a window air conditioner, a split air conditioner or a cabinet air conditioner. If the air conditioner is a window air conditioner, the axial flow wind wheel is arranged on the outdoor side of the window air conditioner; if the air conditioner is a split air conditioner, the axial flow wind wheel is arranged on the outdoor unit of the split air conditioner. Of course, in other embodiments, the axial flow wind wheel may also be installed in a fan or a blower.

[0037] See also Figure 1 In the following embodiments of the present invention, the air conditioner is a split air conditioner including an air conditioner outdoor unit 100. The air conditioner outdoor unit 100 includes a housing 110, a front panel 120 mounted on the housing 110, the front panel 120 is provided with an air outlet, the air outlet is provided with an air outlet mesh cover 130, the axial flow wind wheel is installed in the housing 110, and the air outlet side of the axial flow wind wheel is opposite to the air outlet. Wherein, the axial flow wind wheel is installed in the air conditioner outdoor unit. The axial flow wind wheel rotates to supply air to the outdoor side, so as to discharge heat to the outdoor side. The axial flow wind wheel can reduce the turbulence generated on the fan blade 300, thereby reducing the turbulence noise generated by the fan blade 300. In this embodiment, the axial flow wind wheel is installed in the air conditioner.

[0038] See also Figures 2 to 4 In one embodiment of the axial flow wind wheel of the present invention, the axial flow wind wheel comprises a hub 200 and a plurality of wind blades 300 arranged on the hub 200, and the blade edges of the wind blades 300 comprise a blade root edge 30a, a front blade edge 30b, a blade top edge 30c and a rear blade edge 30d connected in sequence from beginning to end (the wind blade rotates from back to front, such as Figure 2 As shown by the dashed arrow in the middle, at the same circumferential position of the wind blade 300, the circumferential span from the front blade edge 30b to the rear blade edge 30d is D0, and the circumferential span from the dividing strip 330 connecting the blade root edge 30a and the blade top edge 30c to the front blade edge 30b is D1, D1 / D0∈[0.2, 0.4]; and at this circumferential position, the thickness of the wind blade 300 at the dividing strip 330 is greater than the thickness at other positions, and the thickness of the rear blade edge 30d is less than the thickness of the front blade edge 30b.

[0039] Specifically, a plurality of fan blades 300 are evenly spaced on the outer circumference of the hub 200, and the hub 200 is connected to a driving motor, so as to be driven by the driving motor to rotate and drive the fan blades 300 to rotate, thereby guiding the airflow inside the air conditioner to the outdoor side and exhausting air to the outdoor side. As for the number of the fan blades 300, there is no specific limitation, and it can be 3 to 5. Specifically, in this embodiment, the number of the fan blades 300 is 3.

[0040] See also Figure 4In this embodiment, at the same circumferential position of the fan blade 300, the ratio of the circumferential span from the partition strip 330 to the front blade edge 30b (i.e., D1) to the circumferential span from the front blade edge 30b to the rear blade edge 30d (i.e., D0) is D1 / D0∈[0.2, 0.4], which is equivalent to the partition strip 330 being located at a position 0.2D0~0.4D0 closer to the front blade edge 30b on the fan blade 300. And at this circumferential position, the thickness of the fan blade 300 at the partition strip 330 position is greater than the thickness at other positions, and the thickness at the rear blade edge 30d is less than the thickness at the front blade edge 30b, that is, the maximum thickness position of the fan blade 300 appears on the partition strip 330, and the thickness at other positions of the fan blade 300 is less than the thickness on the partition strip 330 of the fan blade 300, that is, the blade surface of the fan blade 300 is raised at the position where the partition strip 330 is located relative to other positions. It is worth noting that the ridge should smoothly transition to the blade surface of the fan blade 300 from the front and rear sides, so that the slope of the ridge is relatively gentle. It should be noted that in this embodiment and the following embodiments, the numerical dimensions (except thickness) of the technical features defined are the dimensions obtained by the corresponding projection of the axial flow fan wheel on the horizontal plane when the axial flow fan wheel is placed horizontally.

[0041] like Figure 7-A As shown ( Figure 7-A W in the middle indicates the direction of air flow). When the axial flow wind wheel is working, the fan blade 300 rotates, and the front blade edge 30b intercepts the airflow forward. The airflow blows over the blade surface of the fan blade 300 through the front blade edge 30b and flows backward 9. The airflow first flows to the dividing strip 330. Affected by the raised slope of the dividing strip 330, the airflow has a tendency to flow "close" to the blade surface of the fan blade 300 behind the dividing strip 330. After the airflow flows through the dividing strip 330, the airflow continues to move backward along the blade surface of the fan blade 300 located behind the dividing strip 330, thereby effectively pushing the airflow backward at the separation point on the blade surface of the fan blade 300, thereby reducing the generation of turbulence and achieving the effect of reducing turbulent noise.

[0042] like Figure 7-B As shown ( Figure 7-B W in the figure indicates the airflow direction), while in a conventional axial flow fan wheel, the thickness of the fan blade 300 at the same circumferential position is equal, and the airflow moves backward directly along the blade surface of the fan blade 300 from the front blade edge 30b of the conventional fan blade 300. The airflow is separated from the blade surface of the fan blade 300 before reaching the rear blade edge 30d. The separated airflow forms turbulence on the blade surface of the fan blade 300, thereby generating greater turbulent noise.

[0043] It is worth explaining here that the dividing strip 330 is actually a part of the fan blade 300 itself, and D1 should actually be the circumferential span from the radial bisector of the dividing strip 330 to the front blade edge 30b. As for the specific value of D1 / D0, it can be 0.2, 0.25, 0.3 or 0.35. However, D1 / D0 should not be less than 0.2, otherwise the effect of the dividing strip 330 pushing the airflow separation point backward is not obvious, and the noise reduction effect is not good; and D1 / D0 should not be greater than 0.4, otherwise the dividing strip 330 will affect the stability of the airflow flowing on the fan blade 300, and it is not easy to form a stable airflow. Therefore, it is necessary to keep D1 / D0 in the range of 0.2~0.4.

[0044] In order to verify the technical effect achieved by the axial flow wind wheel of the present invention, the axial flow wind wheel of the present invention and the conventional axial flow wind wheel were tested under the same number of wind blades 300 and working conditions, and the measured data are as follows:

[0045] Table 1. Conventional axial flow wind wheel, measured parameters

[0046]

[0047] Table 2. Measured parameters of the axial flow wind wheel of the present invention

[0048]

[0049] According to the data measured in Table 1 and Table 2 above, a speed-air volume comparison test chart is drawn (such as Fig.11 as shown) and air volume-noise comparison test chart (as shown Fig.12 As shown). It can be seen that under the same rotation speed condition, compared with the conventional axial flow wind wheel, although the air volume and power of the axial flow wind wheel of the present invention are basically the same as those of the conventional axial flow wind wheel, the noise of the axial flow wind wheel of the present invention is significantly reduced, which is reduced by nearly 2dB, greatly improving the noise problem of the axial flow wind wheel.

[0050] The technical solution of the present invention is to provide a dividing strip 330 connecting the root edge 30a and the top edge 30c of the fan blade 300, and the ratio of the circumferential span from the dividing strip 330 to the front blade edge 30b to the circumferential span from the front blade edge 30b to the rear blade edge 30d is D1 / D0∈[0.2, 0.4], and at this circumferential position, the thickness of the fan blade 300 at the dividing strip 330 is greater than the thickness at other positions, and the thickness of the rear blade edge 30d is less than the thickness of the front blade edge 30b, so that the maximum thickness position of the fan blade 300 appears on the dividing strip 330, and the blade surface of the fan blade 300 is raised at the position of the dividing strip 330 relative to other positions.

[0051] When the axial flow wind wheel is working, the front blade edge 30b intercepts the airflow forward, and the airflow blows through the blade surface of the wind blade 300 through the front blade edge 30b and flows backward. The airflow first flows to the dividing strip 330. Affected by the raised slope of the dividing strip 330, the airflow has a tendency to flow "close to" the blade surface of the wind blade 300 behind the dividing strip 330. After the airflow flows through the dividing strip 330, the airflow continues to move backward along the blade surface of the wind blade 300 located behind the dividing strip 330, thereby effectively pushing the airflow backward at the separation point on the blade surface of the wind blade 300, thereby reducing the generation of turbulence and achieving the effect of reducing turbulent noise. It can be seen that, compared with conventional axial flow wind wheels, the axial flow wind wheel of the present invention can effectively push the airflow backward at the separation point on the blade surface of the wind blade 300, thereby reducing the turbulence generated on the wind blade 300, and thereby reducing the turbulent noise generated by the wind blade 300.

[0052] Furthermore, since the thickness of the rear blade edge 30d is less than that of the front blade edge 30b, on the one hand, the front blade edge 30b can have better strength and can withstand the impact of airflow with higher wind speed; on the other hand, the rear blade edge 30d can have a better wake, which effectively improves the wake flow on the rear side of the wind blade 300 and reduces the wake noise.

[0053] See also Figure 4 and Figure 5 Based on the above embodiment, in order to improve the stability of the airflow flowing on the blade surface of the fan blade 300 and reduce the generation of turbulent noise, the partition strip 330 divides the fan blade 300 into a front blade portion 310 and a rear blade portion 320. At the same circumferential position of the fan blade 300, the thickness of the front blade portion 310 gradually decreases from the partition strip 330 to the front blade edge 30b, and the thickness of the rear blade portion 320 gradually decreases from the partition strip 330 to the rear blade edge 30d.

[0054] Specifically, the front side of the partition bar 330 is connected to the front blade portion 310 by a concave arc smooth transition, and the thickness of the front blade portion 310 gradually decreases from the partition bar 330 to the front blade edge 30b, thereby forming an inclined surface inclined to the front blade edge 30b at the front blade portion 310. The rear side of the partition bar 330 is connected to the rear blade portion 320 by a concave arc smooth transition, and the thickness of the rear blade portion 320 gradually decreases from the partition bar 330 to the rear blade edge 30d, thereby forming an inclined surface inclined to the rear blade edge 30d at the rear blade portion 320.

[0055] When the airflow flows on the surface of the fan blade 300, the airflow first flows from the front blade edge 30b along the inclined surface of the front blade portion 310 to the dividing strip 330. After flowing through the dividing strip 330, the airflow tends to flow toward the surface of the rear blade portion 320, and gradually moves along the inclined surface of the rear blade portion 320 to the rear blade edge 30d, which greatly helps to push the airflow backward at the separation point on the surface of the fan blade 300.

[0056] Please combine Figure 4 , Figure 8 and Fig. 9 For the convenience of explanation, it is defined as follows: on the fan blade 300, according to any angle R with the hub 200 as the center m The circumferential section cut around the radius is S m , this circumferential section S m is a virtual cross section for explanation. Therefore, the circumferential cross section of the fan blade 300 is cut according to the circumference of R1, R2, R3, R4, and R5 on the fan blade 300, and the circumferential cross section S1, circumferential cross section S2, circumferential cross section S3, circumferential cross section S4 and circumferential cross section S5 are obtained in sequence, and R1 to R5 increase in sequence. m Take P1 to P m There are m sampling points in total, and each circumferential section S is recorded. m Corresponding P1 to P m The thickness of the sampling point. In this embodiment, m=6 is taken as an example, where P1 and P2 are located in the front leaf portion 310, and P1 belongs to the front leaf edge 30b; P3 is located in the partition bar 330; P4 to P6 are located in the rear leaf portion 320, and P6 belongs to the rear leaf edge 30d. Each circumferential section S m The thickness data records of the locations of sampling points P1 to P6 are shown in Table 3 below:

[0057] Table 3. Thickness dimensions at different locations of each circumferential section

[0058]

[0059] It can be seen from the above table that at any circumferential position of the fan blade 300 (i.e., a single circumferential cross-section), the maximum thickness position of the fan blade 300 is located on the dividing strip 330, and at this circumferential position, the thickness of the front blade portion 310 gradually decreases from the dividing strip 330 to the front blade edge 30b, and the thickness of the rear blade portion 320 gradually decreases from the dividing strip 330 to the rear blade edge 30d.

[0060] See also Figure 4 and Figure 5 , it is further considered that the thickness of the fan blade 300 at the position of the dividing strip 330, the thickness of the front blade edge 30b, and the thickness of the rear blade edge 30d should not be too different, otherwise it will cause the thickness difference at each position of the fan blade 300 to be too large, which is not conducive to the stable flow of airflow. Therefore, preferably, the thickness of the fan blade 300 at the position of the dividing strip 330 is H0, the thickness of the front blade edge 30b is H1, and the thickness of the rear blade edge 30d is H2. At the same circumferential position of the fan blade 300, H0-H1∈[0.3mm, 1.5mm], H0-H2∈[2.5mm, 5mm].

[0061] For ease of description, it is defined herein that △H1=H0-H1, △H2=H0-H2, then △H1∈[0.3mm, 1.5mm], △H2∈[2.5mm, 5mm]. At the same radial position of the fan blade 300, △H1 may be a fixed constant value, such as 0.3mm, 0.5mm or 1mm, or △H1 may gradually increase with the increase of the circumferential radius of the fan blade 300, for example, gradually increase from 0.3mm to 1mm or 1.5mm. Similarly, at the same radial position of the fan blade 300, △H2 may also be a fixed constant value, such as 3mm, 3.5mm or 4mm, and △H2 may gradually decrease with the increase of the circumferential radius of the fan blade 300, for example, gradually decrease from 5mm to 2mm or 2.5mm.

[0062] Based on the data in Table 3 above, the comparative data of △H1 and △H2 corresponding to each circumferential section can be obtained as shown in Table 4 below:

[0063] Table 4. Comparison data of △H1 and △H2 corresponding to each circumferential section

[0064]

[0065] From the data analysis of Table 4 above, it can be seen that at the same radial position of the fan blade 300, as the circumferential section S m As the radius of the ring increases, △H1 gradually increases, while △H2 gradually decreases.

[0066] In order to verify the effect of the thickness change of the front blade portion 310 and the rear blade portion 320 of the fan blade 300 on the axial flow fan wheel, based on the test experiment of the above embodiment, the axial flow fan wheel is further tested at the same rotation speed, and the experiment is as follows:

[0067] Table 5. Measured parameters of the axial flow wind wheel of the present invention

[0068]

[0069] It can be analyzed from Table 1, Table 2 and Table 5 that at the same speed, the noise of the axial flow wind wheel in this embodiment is reduced by nearly 2.4dB compared with the conventional axial flow wind wheel, and the noise reduction effect is better. That is to say, by limiting the same radial position of the wind blade 300, as the circumferential section S of the wind blade increases, the noise level of the axial flow wind wheel increases. m As the circumferential radius increases, ΔH1 gradually increases, while ΔH2 gradually decreases, so that the axial flow wind wheel can achieve a better noise reduction effect.

[0070] In this embodiment, at the same radial position of the wind blade 300, the thickness of the wind blade 300 gradually decreases from the blade root edge 30a to the blade top edge 30c. Such a configuration can make the thickness of the portion of the wind blade 300 adjacent to the blade root edge 30a larger to ensure the stability of the connection between the wind blade 300 and the hub 200, while the thickness of the portion of the wind blade 300 adjacent to the blade root edge 30a is smaller, and its diversion force is better, which is beneficial to reducing wind loss.

[0071] See also Figure 5 Here, it should be noted that the thickness of the fan blade 300 at the position of the partition bar 330, the thickness of the front blade edge 30b, and the thickness of the rear blade edge 30d should not be too large, otherwise the thickness of the fan blade 300 itself will increase, making the wind resistance of the fan blade 300 larger and consuming more power; and these three should not be too small, otherwise the thickness of the fan blade 300 itself is too small, resulting in a weak strength of the fan blade 300, which is easy to deform during high-speed rotation. Therefore, preferably, H0∈[4.5mm, 7.6mm]; H1∈[3.0mm, 7.3mm]; H2∈[1.7mm, 2.5mm].

[0072] Specifically, for the partition bar 330, in the radial direction of the fan blade 300, the thickness H0 of the partition bar 330 can be gradually increased from 4.5 mm to 7 mm or 7.6 mm, or H0 can be gradually increased from 5 mm to 7.6 mm. For the front blade edge 30b, in the radial direction of the fan blade 300, the thickness H1 of the front blade edge 30b can be gradually increased from 3.0 mm to 6 mm or 7 mm, or H1 can be gradually increased from 4 mm to 7 mm. For the rear blade edge 30d, in the radial direction of the fan blade 300, the thickness H2 of the rear blade edge 30d can be gradually increased from 1.7 mm to 2 mm or 2.5 mm, or H2 can be gradually increased from 2 mm to 2.5 mm.

[0073] See also Figure 4 and Figure 6 Based on the above embodiment, in order to increase the air volume and air pressure of the axial flow wind wheel, improve the work efficiency and reduce the noise, in this embodiment, at the same circumferential position of the wind blade 300, the angle formed by the blade chord line 10 connecting the front blade edge 30b and the rear blade edge 30d and the axial flow wind wheel rotation plane 20 is α, and the α is gradually reduced in the radial direction of the wind blade 300. It should be noted that the blade chord line 10 is a virtual line segment used to explain the shape structure of the wind blade 300.

[0074] Here, it is considered that the angle α formed by the blade chord line 10 and the axial flow wind wheel rotation plane 20 should not be too large or too small, otherwise it is difficult to achieve the effect of reducing noise. In order to verify the influence of the angle formed by the blade chord line 10 and the axial flow wind wheel rotation plane 20 on the noise reduction effect in the radial direction of the wind blade 300, the following test is carried out at the same speed: wherein R1 to R7 are all circumferential radii centered on the hub 200, and R1 to R7 increase in sequence, and different sizes of angles α are tested at each circumferential position of the wind blade 300, and the noise value test data corresponding to (α, R) are obtained as shown in Table 6 below:

[0075] Table 6. Measured parameters of the axial flow wind wheel of the present invention

[0076]

[0077] From the above Table 6, we can get:

[0078] At (20°, R1), the noise value is 51.5dB;

[0079] At (22°, R2), the noise value is 51.2dB;

[0080] At (24°, R3), the noise value is 50.5dB;

[0081] At (26°, R4), the noise value is 50.1dB;

[0082] At (28°, R5), the noise value is 50.8dB;

[0083] At (30°, R6), the noise value is 51.7dB.

[0084] That is to say, in the radial direction of the fan blade 300, as the circumferential radius of the blade surface of the fan blade 300 increases, when α increases from 18° to 20°, the noise of the axial flow wind wheel is basically above 52dB, and even reaches 55.4dB; in this direction, when α is gradually increased from 20° to 30°, the noise of the axial flow wind wheel remains at a low level, basically less than 52dB; in this direction, when α is gradually increased from 30°, the noise of the axial flow wind wheel increases again to above 52dB. It can be seen that at the same circumferential position of the fan blade 300, when α gradually increases from 20° to 30° in the radial direction of the fan blade 300, the noise reduction effect of the axial flow wind wheel is better. Therefore, preferably, α∈[20°, 30°].

[0085] Obviously, in the radial direction of the fan blade 300, as the circumferential radius of the blade surface of the fan blade 300 increases, when α is gradually increased from 20° to 28°, the noise reduction effect of the axial flow fan wheel is the best, which is less than 51.5dB. At this time, the bending angle of the entire blade surface of the fan blade 300 is not too large, and the air volume and air pressure of the axial flow fan wheel are increased, which can not only reduce noise, but also obtain a larger air volume. Therefore, in this embodiment, α∈[20°, 28°] is preferred.

[0086] See also Figure 8 and Fig. 9 In order to ensure the stability of the connection between the fan blade 300 and the hub 200 and to improve the air supply capacity of the fan blade 300, the angle α formed by the blade chord line 10 of the fan blade 300 and the rotating plane 20 of the axial flow wind wheel can be limited to decrease rapidly near the hub 200 and decrease slowly away from the hub 200.

[0087] In this embodiment, the radius of the circumference where the blade top edge 30c is located is R0, and the radius of the circumference where any blade chord line 10 is located is R m The radius coefficient of the ring where the blade chord line 10 is located is k, k=R m / R0,R m ∈[0,R0]:

[0088] When k∈[0, 0.1], α=28-30k;

[0089] When k∈(0.1, 0.4], α=26-10k;

[0090] When k∈(0.4, 1], α=23.3-3.3k.

[0091] See also Fig. 9 and Fig.10 , due to R m ∈[0, R0], k=R m / R0, so k∈[0,1], with the radius R of the ring where the blade chord line 10 is located m As the radius coefficient k increases, the radius coefficient k gradually increases. When k∈[0, 0.1], α=28-30k, that is, as the radius coefficient k increases from 0 to 0.1, α decreases rapidly from 28° to 25°. When k∈(0.1, 0.4], α=26-10k, that is, as the radius coefficient k increases from 0.1 to 0.4, α gradually decreases from 25° to 22°. When k∈(0.4, 1], α=23.3-3.3k, that is, as the radius coefficient k increases from 0.4 to 1, α gradually decreases slowly from 22° to 20°.

[0092] It can be seen that by limiting the α to decrease rapidly near the hub 200, a larger installation angle is formed between the blade root position of the fan blade 300 and the hub 200, which can not only enhance the stability of the connection between the fan blade 300 and the hub 200, but also improve the air supply capacity of the fan blade 300. The α decreases slowly at a position away from the hub 200, so that the blade surface of the fan blade 300 at the blade tip position is relatively flat, which can reduce the formation of blade tip leakage vortex, thereby reducing noise.

[0093] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An axial flow wind wheel, comprising a hub and a plurality of wind blades arranged on the hub, characterized in that: The blade edge of the wind blade includes a blade root edge, a front blade edge, a blade top edge and a rear blade edge connected in sequence from beginning to end. At the same circumferential position of the wind blade, the circumferential span from the front blade edge to the rear blade edge is D0, and the circumferential span from the dividing strip connecting the blade root edge and the blade top edge to the front blade edge is D1, D1 / D0∈[0.25, 0.4]; And at the circumferential position, the thickness of the fan blade at the position of the dividing strip is greater than the thickness at other positions, the thickness of the rear blade edge is less than the thickness of the front blade edge, and the blade surface of the fan blade is raised at the position of the dividing strip relative to other positions; The partition strip is arranged in a strip shape; The partition strip divides the fan blade into a front blade portion and a rear blade portion. At the same circumferential position of the fan blade, the thickness of the front blade portion gradually decreases from the partition strip to the front blade edge, and the thickness of the rear blade portion gradually decreases from the partition strip to the rear blade edge. The thickness of the fan blade at the position of the dividing strip is H0, the thickness of the front blade edge is H1, and the thickness of the rear blade edge is H2. At the same circumferential position of the fan blade, H0-H1∈[0.3mm, 1.5mm], H0-H2∈[2.5mm, 5mm]; At the same circumferential position of the fan blade, the angle formed by the blade chord line connecting the front blade edge and the rear blade edge and the rotation plane of the axial flow wind wheel is α, and the angle α is gradually reduced in the radial direction of the fan blade; α∈[20°，28°]； The radius of the ring where the blade top edge is located is R0, and the radius of the ring where any blade chord line is located is R m The radius coefficient of the ring where the blade chord line is located is k, k=R m / R0,R m ∈[0, R0]: When k∈[0, 0.1], α=28-30k; When k∈(0.1, 0.4], α=26-10k; When k∈(0.4, 1], α=23.3-3.3k.

2. The axial flow wind wheel according to claim 1, characterized in that: At the same radial position of the fan blade, the thickness of the fan blade gradually decreases from the blade root edge to the blade top edge.

3. An air conditioner, characterized in that: The air conditioner comprises the axial flow fan wheel as described in any one of claims 1 to 2.

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