Patent Application
20200332807
The present disclosure relates to the technical field of air conditioners, in particular to an axial flow impeller and an air conditioner.
An axial flow impeller is commonly used in a household appliance or an air conditioner to serve as a ventilation device. When rotating, the axial flow impeller drives the air in its circumferential direction to rotate, forming an airflow, and drives the air flow to blow out along the axial direction of the axial flow impeller. Thicknesses of the blade of the conventional axial flow impeller at various positions of the same circumference are basically equal. When the airflow flows from a front blade edge to a rear blade edge of the blade, the airflow separates before reaching the rear blade edge. As a result, the airflow becomes turbulent at a position adjacent to the rear blade edge of the blade, which generates a large turbulent noise.
The main objective of the present disclosure is to provide an axial flow impeller, which aims to reduce the turbulence generated at the blade, and thereby reduce the turbulence noise generated by the blade.
In order to achieve the above objective, the present disclosure provides an axial flow impeller including a hub and a plurality of blades provided at the hub, where: a blade edge of the blade includes a blade root edge, a front blade edge, a blade top edge and a rear blade edge connected sequentially, at a same circumference of the blade, a circumferential span from the front blade edge to the rear blade edge is D0, a circumferential span from a divider strip connecting the blade root edge and the blade top edge to the front blade edge is D1, D1/D0 is equal to or greater than 0.2 and equal to or smaller than 0.4, i.e., D1/D0ϵ[0.2, 0.4] and at the this circumference, a thickness of the blade at the divider strip is greater than thicknesses of the blade at other positions, and a thickness of the rear blade edge is smaller than a thickness of the front blade edge.
In some embodiments, the divider strip is configured to divide the blade into a front blade portion and a rear blade portion, at the same circumference of the blade, a thickness of the front blade portion gradually decreases from the divider strip to the front blade edge, and a thickness of the rear blade portion gradually decreases from the divider strip to the rear blade edge.
In some embodiments, the thickness of the blade at the divider strip is H0, the thickness of the front blade edge is H1, the thickness of the rear blade edge is H2, ΔH1 is equal to H0−H1, ΔH2 is equal to H0−H2, and at the same circumference of the blade, ΔH1 is equal to or greater than 0.3 mm and equal to or smaller than 1.5 mm, i.e., H0−H1ϵ[0.3 mm, 1.5 mm], ΔH2 is equal to or greater than 2.5 mm and equal to or smaller than 5 mm, H0−H2ϵ[2.5 mm, 5 mm].
In some embodiments, H0 is equal to or greater than 4.5 mm and equal to or smaller than 7.6 mm, i.e., H0ϵ[4.5 mm, 7.6 mm], H1 is equal to or greater than 3.0 mm and equal to or smaller than 7.3 mm, i.e., H1ϵ[3.0 mm, 7.3 mm], and H2 is equal to or greater than 1.7 mm and equal to or smaller than 2.5 mm, i.e., H2ϵ[1.7 mm, 2.5 mm].
In some embodiments, at a same radial direction of the blade, the thickness of the blade gradually decreases from the blade root edge to the blade top edge.
In some embodiments, at the same circumference of the blade, an angle formed by a blade chord line connecting the front blade edge and the rear blade edge and a rotation plane of the axial flow impeller is α, and α gradually decreases in a radial direction of the blade.
In some embodiments, α is equal to or greater than 20° and equal to or smaller than 30°, i.e., αϵ[20°, 30° ].
In some embodiments, α is equal to or greater than 20° and equal to or smaller than 28°, i.e., αϵ[20°, 28° ].
In some embodiments, a radius corresponding to a circumference at which the blade top edge lies is denoted as R0, a radius corresponding to a circumference at which a blade chord line lies is denoted as Rm, and a radius coefficient of the circumference of the blade chord line is denoted as k, k is equal to Rm/R0, and Rm is equal to or greater than 0 and equal to or smaller than R0, i.e., Rmϵ[0, R0]. Then when k is equal to or greater than 0 and equal to or smaller than 0.1, i.e., when kϵ[0, 0.1], α=28°−k×30°; when k is greater than 0.1 and equal to or smaller than 0.4, i.e., when kϵ(0.1, 0.4], α=26°−k×10°; and when k is greater than 0.4 and equal to or smaller than 1, i.e., when kϵ(0.4, 1], α=23.3°−k×3.3°.
In the technical solutions of the present disclosure, a divider strip connecting the blade root edge and the blade top edge is provided at the blade. The ratio D1/D0 of the circumferential span from the divider strip to the front blade edge to the circumferential span from the front blade edge to the rear blade edge is equal to or greater than 0.2 and equal to or smaller than 0.4. At the circumference, the thickness of the blade at the divider strip is greater than the thicknesses of the blade at other positions, and the thickness of the rear blade edge is smaller than the thickness of the front blade edge, such that the position of the maximum thickness of the blade appears at the divider strip, and the blade surface of the blade is raised at the position where the divider strip is located relative to other positions.
When the axial flow impeller operates, the front blade edge grabs the air flow forwards, the airflow blows through the blade surface of the blade through the front blade edge and flows backwards, and the airflow first flows to the divider strip. Affected by the slope of the bulge of the divider strip, the airflow has a tendency to flow “closer” to the blade surface of the blade at the rear side of the divider strip. After the airflow flows past the divider strip, the airflow continues to move backwards along the blade surface of the blade at the rear side of the divider strip. Therefore, the airflow is effectively moved backwards at the separation point of the blade surface of the blade, thereby reducing the generation of turbulent flow and reducing the turbulent noise. It can be seen that, compared with the conventional axial flow impeller, the axial flow impeller of the present disclosure can effectively move the airflow backwards at the separation point of the blade surface of the blade, thereby reducing the turbulence generated at the blade and reducing the turbulent noise generated by the blade.
Further, since the thickness of the rear blade edge is smaller than the thickness of the front blade edge, on the one hand, the front blade edge has better strength and can bear the impact of the airflow with a larger wind speed; on the other hand, the rear blade edge can have a better trail, which can effectively improve the trail flow at the rear side of the blade and reduce the trail noise.
In order to more clearly illustrate the embodiments of the present disclosure, the drawings used in the embodiments will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present disclosure. It will be apparent to those skilled in the art that other figures can be obtained from the structures illustrated in the drawings without inventive effort.
The realization of the objective, functional characteristics, advantages of the present disclosure are further described with reference to the accompanying drawings.
The technical solutions of the embodiments of the present disclosure will be clearly described in the following with reference to the accompanying drawings. It is obvious that the described embodiments are only some rather than all of the embodiments of the present disclosure. All other embodiments obtained by persons skilled in the art based on the embodiments of the present disclosure without creative efforts shall fall within the scope of the present disclosure.
It should be noted that, if there is directional indication (such as up, down, left, right, front, rear . . . ) in the embodiments of the present disclosure, the directional indication is only used to explain the relative positional relationship and movement between the components in a certain attitude (as shown in the Figures). If the specific attitude changes, the directional indication changes accordingly.
In addition, the descriptions, such as “first,” “second” in the embodiments of the present disclosure, are merely for descriptive purposes, and should not be understood as indicating or suggesting relative importance or impliedly indicating the number of the indicated technical feature. Therefore, the feature associated with the “first,” the “second” can expressly or impliedly include at least one such feature. Besides, the technical solutions of various embodiments can be combined with each other as long as they do not conflict with each other.
The present disclosure provides an axial flow impeller and air conditioner. 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 impeller is provided at the outdoor side of the window air conditioner; if the air conditioner is a split air conditioner, the axial flow impeller is provided at the outdoor unit of the split air conditioner. In other embodiments, the axial flow impeller may also be provided in a fan of the air conditioner.
Referring to
Referring to
Specifically, the plurality of blades 300 are evenly spaced around the outer circumference of the hub 200. The hub 200 is configured to connect with the driving motor, and driven by the driving motor to rotate the blade 300, to guide the airflow inside the air conditioner to the outdoor and exhaust the air to the outdoor. The number of the blades 300 is not specifically limited, and may be 3 to 5, in this embodiment, the number of the blades 300 is 3.
Referring to
As shown in
However, as shown in
It should be noted here, the divider strip 330 is actually a part of the blade 300 itself, and D1 should actually be the circumferential span from the radial bisector, i.e., a bisection line along the radial direction, of the divider strip 330 to the front blade edge 30b. The specific value of D1/D0 may be 0.2, 0.25, 0.3, or 0.35. A value of D1/D0 less than 0.2 may not provide obvious effect of the divider strip 330 moving the airflow separation point backward, and the noise reduction effect is not good. On the other hand, a value of D1/D0 greater than 0.4 may cause the divider strip 330 to affect the stability of the airflow flowing on the blade surface of the blade 300, and it is not easy to form a stable airflow. Therefore, in some embodiments, D1/D0 is maintained in the range of 0.2 to 0.4.
In order to verify the technical effect achieved by the axial flow impeller of the present disclosure, the axial flow impeller of the present disclosure and the conventional axial flow impeller were tested with the same number of blades 300 and under the same working conditions, and the measured data is as follows:
Based on the measured data shown in Tables 1 and 2 above, a speed-air volume test comparison diagram (as shown in
In the technical solutions of the present disclosure, a divider strip 330 connecting the blade root edge 30a and the blade top edge 30c is provided at the blade 300. The ratio D1/D0 of the circumferential span from the divider 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 equal to or greater than 0.2 and equal to or smaller than 0.4. At the circumference, the thickness of the blade 300 at the divider strip 330 is greater than the thicknesses of the blade 300 at other positions, and the thickness of the rear blade edge 30d is smaller than the thickness of the front blade edge 30b. That is, the position of the maximum thickness of the blade 300 is at the divider strip 330. That is, the blade surface of the blade 300 is raised relative to other positions at the position where the divider strip 330 is located.
When the axial flow impeller operates, the blade 300 rotates, the front blade edge 30b grabs the air flow forwards, the airflow blows through the blade surface of the blade 300 through the front blade edge 30b and flows backwards 9, and the airflow first flows to the divider strip 330. Affected by the slope of the bulge of the divider strip 330, the airflow has a tendency to flow “closer” to the blade surface of the blade 300 at the rear side of the divider strip 330. After the airflow flows past the divider strip 330, the airflow continues to move backwards along the blade surface of the blade 300 at the rear side of the divider strip 330. Therefore, the airflow is effectively moved backwards at the separation point of the blade surface of the blade 300, thereby reducing the generation of turbulent flow and reducing the turbulent noise. It can be seen that, compared with the conventional axial flow impeller, the axial flow impeller of the present disclosure can effectively move the airflow backwards at the separation point of the blade surface of the blade 300, thereby reducing the turbulence generated at the blade 300, and reducing the turbulent noise generated by the blade 300.
Further, since the thickness of the rear blade edge 30d is smaller than the thickness of the front blade edge 30b, on the one hand, the front blade edge 30b has better strength and can bear the impact of the airflow with a larger wind speed; on the other hand, the rear blade edge 30d can have a better trail, which can effectively improve the trail flow at the rear side of the blade 300 and reduce the trail noise.
Referring to
Specifically, a concave arc is used to smoothly transition and connect the front side of the divider strip 330 to the front blade portion 310. The thickness of the front blade portion 310 gradually decreases from the divider strip 330 to the front blade edge 30b, so that an inclined surface inclined towards the front blade edge 30b is formed in the front blade portion 310. The concave arc is used to smoothly transition and connect the rear side of the divider strip 330 to the rear blade portion 320. The thickness of the rear blade portion 320 gradually decreases from the divider strip 330 to the rear blade edge 30d, so that an inclined surface inclined towards the rear blade edge 30d is formed in the rear blade portion 320.
When the airflow flows on the blade surface of the blade 300, the airflow first flows from the front blade edge 30b along the inclined surface of the front blade portion 310 to the divider strip 330, and after passing the divider strip 330, the airflow tends to flow towards the surface of the rear blade portion 320 and gradually moves along the inclined surface of the rear blade portion 320 towards the rear blade edge 30d, which greatly facilitates the backward movement of the airflow at the separation point of the blade surface of the blade 300.
Referring to
As can be seen from the above table, at any circumference of the blade 300 (i.e., a single circumferential section), the maximum thickness position of the blade 300 is located at the divider strip 330, and at the circumference, the thickness of the front blade portion 310 gradually decreases from the divider strip 330 to the front blade edge 30b, and the thickness of the rear blade portion 320 gradually decreases from the divider strip 330 to the rear blade edge 30d.
Referring to
Hereinafter, ΔH1 equal to H0−H1 and ΔH2 equal to H0−H2 are used for description. Thus, in some embodiments, ΔH1 is equal to or greater than 0.3 mm and equal to or smaller than 1.5 mm, and ΔH2 is equal to or greater than 2.5 mm and equal to or smaller than 5 mm. At the same radial position of the blade 300, ΔH1 may be a fixed constant value, for example, 0.3 mm, 0.5 mm or 1 mm. In some embodiments, ΔH1 gradually increases with the increase of a circumferential radius, i.e., a radius of a circumference, of the blade 300, for example, from 0.3 mm to 1 mm or 1.5 mm. Likewise, at the same radial position of the blade 300, ΔH2 may be a fixed constant value, for example, 3 mm, 3.5 mm or 4 mm. In some embodiments, ΔH2 gradually decreases with the increase of the circumferential radius of the blade 300, for example, from 5 mm to 2 mm or 2.5 mm.
Based on the data in Table 3 above as an example, the comparison data of ΔH1 and ΔH2 corresponding to the circumferential sections can be obtained as shown in Table 4 below:
According to the data in Table 4 above, at the same radial position of the blade 300, as the circumferential radius of the circumferential section Sm on the blade increases, ΔH1 gradually increases, and ΔH2 gradually decreases.
In order to confirm the effect of the thickness variation of the front blade portion 310 and the rear blade portion 320 of the blade 300 on the axial flow impeller, based on the test experiment of the above embodiments, the axial flow impeller is further tested at the same speed, and the experimental results are as follows:
Based on the analysis of the data in Table 1, Table 2 and Table 5 above it can be seen that at the same rotation speed, the noise of the axial flow impeller in this embodiment is reduced by nearly 2.4 dB compared to the conventional axial flow impeller, and the noise reduction effect is better. That is, at the same radial direction of the blade 300, as the circumferential radius of the circumferential section Sm on the blade increases, ΔH1 gradually increases, while ΔH2 gradually decreases, which causes the axial flow impeller to achieve a better noise reduction effect.
In this embodiment, at the same radial direction of the blade 300, the thickness of the blade 300 gradually decreases from the blade root edge 30a to the blade top edge 30c. As such, the thickness of the portion of the blade 300 adjacent to the blade root edge 30a is relatively large, so as to ensure the stability of the connection between the blade 300 and the hub 200, while the thickness of the portion of the blade 300 adjacent to the blade root edge 30a is relatively small, and the flow guiding capability is better, which is beneficial to reduce air loss.
Referring to
Specifically, in the direction from the blade top edge 30c to the blade root edge 30a of the blade 300, the thickness H0 of the divider strip 330 may gradually increase from 4.5 mm to 7 mm or 7.6 mm, or from 5 mm to 7.6 mm, the thickness H1 of the front blade edge 30b may gradually increase from 3.0 mm to 6 mm or 7 mm, or from 4 mm to 7 mm, and the thickness H2 of the rear blade edge 30d may gradually increase from 1.7 mm to 2 mm or 2.5 mm, or from 2 mm to 2.5 mm.
Referring to
The angle α formed by the blade chord line 10 and the rotation plane 20 of the axial flow impeller 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 rotation plane 20 of the axial flow impeller in the radial direction of the fan blade 300 on the noise reduction effect, the following tests were conducted at the same speed: R1 to R7 are all circumferential radii centered on the hub 200, and R1 to R7 increase sequentially. Tests were performed at each circumference of the blade 300 for different sizes of a to obtain the test data of the noise values corresponding to (α, R) as shown in Table 6 below.
As can be seen from Table 6 above:
At (20°, R1), the noise value is 51.5 dB;
At (22°, R2), the noise value is 51.2 dB;
At (24°, R3), the noise value is 50.5 dB;
At (26°, R4), the noise value is 50.1 dB;
At (28°, R5), the noise value is 50.8 dB;
At (30°, R6), the noise value is 51.7 dB.
That is, as the circumferential radius of the blade surface of the blade 300 increases in the radial direction of the blade 300, α increases from 18° to 20°, the noise of the axial flow impeller is basically above 52 dB, even reaching 55.4 dB. When α gradually increases from 20° to 30° in this direction, the noise of the axial flow impeller is kept at a relatively low level, basically less than 52 dB; in this direction, when α is gradually increased from 30°, the noise of the axial flow impeller is increased to more than 52 dB. As can be seen, at the same circumference of the blade 300, when the α gradually increases from 20° to 30° in the radial direction of the blade 300, the noise reduction effect of the axial flow impeller is better. Therefore, preferably, α is equal to or greater than 20° and equal to or smaller than 30°.
Thus, as the circumferential radius of the blade surface of the blade 300 increases in the radial direction of the blade 300, when α gradually increases from 20° to 28°, the noise reduction effect of the axial flow impeller is the best, all are less than 51.5 dB. And at this time, the bending angle of the entire blade surface of the blade 300 is not too large, and the air volume and air pressure of the axial flow impeller are increased, which can not only reduce the noise, but also obtain a larger air volume. Therefore, in some embodiments, α is chosen to be equal to or greater than 20° and equal to or smaller than 28°.
Referring to
In this embodiment, a radius corresponding to a circumference at which the blade top edge lies is denoted as R0, a radius corresponding to a circumference at which a blade chord line lies is denoted as Rm, and a radius coefficient of the circumference of the blade chord line is denoted as k, where k is equal to Rm/R0 and Rm is equal to or greater than 0 and equal to or smaller than R0.
When k is equal to or greater than 0 and equal to or smaller than 0.1, α=28°−k×30°.
When k is greater than 0.1 and equal to or smaller than 0.4, α=26°−k×10°.
When k is greater than 0.4 and equal to or smaller than 1, α=23.3°−k×3.3°.
Referring to
As can be seen, α decreases rapidly near the hub 200, so that the blade root position of the blade 300 and the hub 200 form a large mounting angle. As such, not only can the stability of the connection between the blade 300 and the hub 200 be enhanced, but also the air supply capability of the blade 300 can be improved. On the other hand, α gradually decreases at positions away from the hub 200, and the blade surface of the blade 300 is gentler, which can reduce the formation of the blade top vortex and thereby reduce noise.
The above are only some embodiments of the present disclosure, and thus do not limit the scope of the present disclosure. Under the inventive concept of the present disclosure, equivalent structural transformations made according to the description and drawings of the present disclosure, or direct/indirect application in other related technical fields are included in the scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201810138859.7 | Feb 2018 | CN | national |
This application is a continuation of International Application No. PCT/CN2018/084877, filed on Apr. 27, 2018, which claims priority to Chinese Application No. 201810138859.7, filed on Feb. 7, 2018, which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2018/084877 | Apr 2018 | US |
| Child | 16918168 | US |
