阅读说明：本技术 轴流风机及具有其的空调室外机 (Axial fan and air conditioner outdoor unit with same ) 是由 孙卫亮 刘博� 徐伟 阮国刚 于 2019-11-20 设计创作，主要内容包括：本发明提供一种轴流风机及具有其的空调室外机。其中,所述轴流风机包括轮毂和与所述轮毂连接的叶片,所述叶片包括连接至所述轮毂的叶根部以及远离所述轮毂的边缘部,在叶片的旋转方向上,所述叶片具有前缘和后缘,所述叶片具有朝上的上表面和朝下的下表面,所述叶片包括靠近所述轮毂的第一叶片区和远离所述轮毂的第二叶片区,所述第一叶片区的上表面呈向下凹陷的曲面,所述第二叶片区的上表面呈向上凸起的曲面。本发明提供的轴流风机可以提高效率和降低噪音。(The invention provides an axial flow fan and an air conditioner outdoor unit with the same. The axial flow fan comprises a hub and blades connected with the hub, the blades comprise blade roots connected to the hub and edge portions far away from the hub, the blades are provided with front edges and rear edges in the rotating direction of the blades, the blades are provided with upward upper surfaces and downward lower surfaces, the blades comprise first blade areas close to the hub and second blade areas far away from the hub, the upper surfaces of the first blade areas are curved surfaces sunken downwards, and the upper surfaces of the second blade areas are curved surfaces protruding upwards. The axial flow fan provided by the invention can improve the efficiency and reduce the noise.)

1. The utility model provides an axial fan, including wheel hub and with the blade that wheel hub is connected, the blade is including being connected to wheel hub's blade root and keeping away from wheel hub's edge portion, in the direction of rotation of blade, the blade has leading edge and trailing edge, its characterized in that, the blade has upper surface up and lower surface down, the blade is including being close to wheel hub's first blade district and keeping away from wheel hub's second blade district, the upper surface in first blade district is undercut curved surface, the upper surface in second blade district is bellied curved surface upwards.

2. The axial flow fan according to claim 1, wherein a ratio of a distance from an outer edge of the first blade region to a rotational axis of the axial flow fan to a distance from an edge portion of the blade to the rotational axis of the axial flow fan is not less than 0.45 and not more than 0.9.

3. The axial fan of claim 2, wherein an outer edge of the first blade region and an inner edge of the second blade region are adjacent.

4. The axial flow fan according to claim 1, wherein a cylindrical surface having a rotation axis of the axial flow fan as a central axis intersects an upper surface of a blade region located within 50% of a distance from the blade root portion to the edge portion to form a sectional curve, and an included angle between the sectional curve and the rotation axis is gradually increased in a direction from a leading edge to a trailing edge of the blade.

5. The axial flow fan according to claim 1, wherein in a sectional curve formed by intersecting a cylindrical surface having a rotation axis of the axial flow fan as a central axis with an upper surface of the blade region located within an interval of 60% to 90% of a distance from the root portion to the edge portion, there is at least one sectional curve whose included angle with the rotation axis in a direction from the leading edge to the trailing edge of the blade is first decreased and then increased.

6. The axial flow fan of claim 2, wherein a radius of curvature of an upper surface of the second blade region gradually increases in a direction from the leading edge to the trailing edge.

7. The axial flow fan of claim 1, wherein a trailing edge of the blade is S-shaped.

8. The axial flow fan according to claim 7, wherein an angle between a line connecting the rotation axis of the axial flow fan and the root portion of the trailing edge and a line connecting the rotation axis of the axial flow fan and the edge portion of the trailing edge as projected on a horizontal plane is 15 to 45 degrees.

9. The axial flow fan of claim 1, wherein the edge portion of the blade has a chamfered surface.

10. The axial fan of claim 1, wherein edge portions of the leading edge and/or the trailing edge have chamfers.

11. An outdoor unit of an air conditioner, comprising the axial flow fan according to any one of claims 1 to 10.

Technical Field

The invention relates to the technical field of fans, in particular to an axial flow fan and an air conditioner outdoor unit with the same.

Background

Axial fans generally include a hub and blades, and during the rotation of the axial fan, the pressures on the two sides of the blades are different, wherein the side with higher pressure is a pressure side, and the side with lower pressure is a suction side. Because a gap exists between the blade and the wind guide ring positioned at the periphery of the blade, fluid on one side of the pressure surface bypasses the blade top to flow to the suction surface, and thus a Tip Leakage Vortex (TLV) is formed at the blade top. The greater the pressure differential, the greater the tip leakage vortex intensity. The tip leakage vortex is a main factor affecting the efficiency of the fan and generating noise. Therefore, it is of great significance to research how to reduce the tip leakage vortex so as to improve the efficiency of the fan and reduce the noise of the fan.

Disclosure of Invention

The invention provides an axial flow fan and an air conditioner outdoor unit with the same, which can improve the efficiency of the fan and reduce noise.

In order to achieve the purpose, the invention is realized by the following technical scheme.

The utility model provides an axial fan, including wheel hub and with the blade that wheel hub is connected, the blade is including being connected to wheel hub's blade root and keeping away from wheel hub's edge portion, in the direction of rotation of blade, the blade has leading edge and trailing edge, wherein, the blade has upper surface up and lower surface down, the blade is including being close to wheel hub's first blade district with keep away from wheel hub's second blade district, the upper surface in first blade district is undercut curved surface, the upper surface in second blade district is bellied curved surface upwards.

Further, the ratio of the distance from the outer edge of the first blade area to the rotation axis of the axial flow fan to the distance from the edge portion of the blade to the rotation axis of the axial flow fan is not less than 0.45 and not more than 0.9.

Further, an outer edge of the first blade region is adjacent to an inner edge of the second blade region.

Furthermore, a cylindrical surface taking the rotation axis of the axial flow fan as a central axis intersects with the upper surface of the blade area located within 50% of the distance from the blade root to the edge portion to form a section curve, and an included angle between the section curve and the rotation axis is gradually increased in the direction from the front edge to the rear edge of the blade.

Further, in a cross-sectional curve formed by intersecting a cylindrical surface with the rotation axis of the axial flow fan as a central axis with the upper surface of the blade region located in an interval of 60% to 90% of the distance from the blade root to the edge portion, at least one cross-sectional curve exists, and an included angle between the cross-sectional curve and the rotation axis in the direction from the leading edge to the trailing edge of the blade is first reduced and then increased.

Further, the radius of curvature of the upper surface of the second blade gradually increases in a direction from the leading edge to the trailing edge.

Further, the trailing edge of the blade is S-shaped.

Furthermore, the included angle between the connecting line of the rotation axis of the axial flow fan and the blade root of the trailing edge and the connecting line of the rotation axis of the axial flow fan and the edge part of the trailing edge in the projection on the horizontal plane is 15-45 degrees.

Further, the edge portion of the blade has a chamfered surface.

Further, the edge portions of the leading edge and/or the trailing edge are chamfered.

The invention also provides an air conditioner outdoor unit, which comprises the axial flow fan in any technical scheme.

According to the axial flow fan provided by the invention, the upper surface of the first blade area of the blade, which is close to the hub, is a curved surface which is sunken downwards, so that the load of the blade area can be increased, the air volume is ensured, and the efficiency is improved; the upper surface in the second blade district of keeping away from wheel hub of blade is the bellied curved surface that makes progress, so set up the load that can reduce this blade district, reduces the deformation in this blade district to reduce the tip and leak vortex intensity, reduce energy loss, but noise abatement simultaneously of lifting efficiency. The air conditioner outdoor unit provided by the invention has the beneficial effects as the axial flow fan is arranged.

Drawings

Fig. 1 is a perspective view of a preferred embodiment of an axial flow fan according to the present invention.

FIG. 2 is a side view of a preferred embodiment of the axial flow fan of the present invention.

FIG. 3 is a schematic top view of a blade partition in accordance with a preferred embodiment of the axial flow fan of the present invention.

FIG. 4 is a top view of an axial flow fan according to a preferred embodiment of the present invention.

Fig. 5 is a sectional view taken along line a-a of fig. 4.

Fig. 6 is a sectional view taken along line B-B of fig. 4.

Fig. 7 is a schematic cross-sectional view taken along line C-C of fig. 4.

FIG. 8 is a bottom view of a preferred embodiment of the axial flow fan of the present invention.

Fig. 9 is a partial enlarged view at D in fig. 1.

Fig. 10 is a partial enlarged view at E in fig. 1.

Fig. 11 is a partial enlarged view at F in fig. 5.

FIG. 12 is a graph comparing test data for noise.

The reference numbers illustrate: 100-axial flow fan; 1-a hub; 2-a blade; 21-leaf root; 22-edge portion; 23-leading edge; 24-the trailing edge; 251-a first blade region; 252-a second blade region; 253-third vane zone; 221-a chamfer plane; 231-leading edge tail chamfer; 241-trailing edge tail chamfer.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

An axial flow fan and an outdoor unit of an air conditioner having the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to fig. 1 and 2, in a preferred embodiment, an axial flow fan 100 of the present invention includes a hub 1 and blades 2 connected to the hub 1.

The hub 1 is roughly cylindrical, a connecting column used for being connected with an output shaft of a motor is arranged in the hub, and a D-shaped hole is formed in the connecting column. And a plurality of radially distributed support ribs are further arranged in the cylindrical hub 1 to enhance the structural strength.

The blade 2 comprises a root portion 21 connected to the outer periphery of the hub 1 and an edge portion 22 remote from the hub 1. In the direction of rotation of the blade 2, as indicated by the arrow in fig. 1, the blade has a leading edge 23 and a trailing edge 24. In the present embodiment, the number of the blades 2 is 3, and the projections of the edge portions 22 of the 3 blades 2 on the horizontal plane are on the same circle. In other embodiments, the number of blades 2 may also be 4, 5 or more.

Referring to fig. 3, the blade 2 includes a first blade region 251 near the hub 1 and a second blade region 252 far from the hub 1. Referring to fig. 4 to 6, the blade 2 has an upward upper surface and a downward lower surface, the upper surface of the first blade area 251 is a downward concave curved surface, and the upper surface of the second blade area 252 is an upward convex curved surface. It should be noted that the above expressions close to the hub 1 and far from the hub 1 are relative to each other between the first blade region 251 and the second blade region 252. That is, the first blade zone 251 is proximate to the hub 1 relative to the second blade zone 252; similarly, the second blade region 252 is remote from the hub 1 with respect to the first blade region 251. In this embodiment, a third blade region 253 is further disposed between the first blade region 251 and the blade root 21 of the blade 2, and an upper surface of the third blade region 253 may be a plane or a curved surface. In other embodiments, the third blade region 253 may not be provided, in other words, the first blade region 251 is formed to extend directly from the blade root 21 to the outside, that is, the inner edge of the first blade region 251 is located at the blade root 21.

Referring to fig. 3 and 5, in the present embodiment, the blade 2 includes a third blade region 253, a first blade region 251 and a second blade region 252 in sequence from the blade root portion 21 to the edge portion 22. A distance from the rotation axis of axial flow fan 100 to the inner edge of first blade region 251 is L1, a distance from the rotation axis of axial flow fan 100 to the outer edge of first blade region 252 is L2, and a distance from the rotation axis of axial flow fan 100 to edge portion 22 is L3. The ratio of the distance from the rotation axis of the axial flow fan 100 to the outer edge of the first blade region 252 being L2 to the distance from the rotation axis of the axial flow fan 100 to the edge portion 22 being L3 is not less than 0.45 and not more than 0.9. The ratio of L2 to L3 can be, for example, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, etc. In this embodiment, the outer edge of the first blade region 251 and the inner edge of the second blade region 252 are adjacent, that is, the outer edge of the first blade region 251 is the intersection point with the first blade region 251 and the second blade region 252. In other embodiments, the outer edge of the first blade region 251 and the inner edge of the second blade region 252 may not be contiguous. For example, one or more regions having a planar or curved upper surface may be disposed between first blade region 251 and second blade region 252. Further, the radius of curvature of the upper surface of the second blade region 252 increases in a direction from the leading edge 23 to the trailing edge 24.

Referring to fig. 4 and 7, a cross section formed by intersecting a cylindrical surface having a rotation axis of the axial flow fan 100 as a central axis and the blade 2, that is, a cross section formed along a line C-C in fig. 4, is schematically illustrated in fig. 7. A cross-sectional curve formed by intersecting a cylindrical surface having the rotation axis of the axial flow fan 100 as a central axis with an upper surface of the blade region located within 50% of the distance from the blade root portion 21 to the edge portion 22 is such that an included angle between the cross-sectional curve and the rotation axis is gradually increased in a direction from the leading edge 23 to the trailing edge 24 of the blade 2. That is, in the schematic view shown in fig. 7, the angle b is an angle between a tangent line of any point on the cross-sectional curve and the rotation axis, and the angle is gradually increased from bottom to top. For a horizontal placement of the fan, the axis of rotation is also the vertical line. In addition, in a cross-sectional curve formed by intersecting a cylindrical surface having the rotation axis of the axial flow fan 100 as the central axis with the upper surface of the blade region located in the interval of 60% to 90% of the distance from the blade root portion 21 to the edge portion 22, at least one cross-sectional curve exists, and an included angle between the cross-sectional curve and the rotation axis in the direction from the leading edge 23 to the trailing edge 24 of the blade 2 is first reduced and then increased. Preferably, the change trend of the included angle which is decreased first and then increased satisfies the parabolic equation. The twisted blade shape thus formed can reduce the amount of deformation of the blade 2 while ensuring the amount of wind, thereby improving efficiency and reducing noise.

Referring to fig. 8, the trailing edge 24 of the blade 2 is S-shaped. The outer side of the axial flow fan 100 is often provided with a protective grid, which comprises a plurality of grid bars. In an embodiment of the present invention, the trailing edge 24 of the blade 2 is set to be S-shaped, and there is a phase difference between each point on the trailing edge 24 passing through a certain grid, so that the interaction between the airflow driven by the blade 2 and the grid is weakened, thereby reducing the possibility of the peak value of the noise in a certain frequency band, and further achieving the effect of reducing the noise. Further, a projection of a connection line between the rotation axis of the axial flow fan 100 and the root 21 of the trailing edge 24 and a connection line between the rotation axis of the axial flow fan 100 and the edge 22 of the trailing edge 24 on a horizontal plane forms an included angle a, and the included angle a is 15 degrees to 45 degrees. Such as 18 degrees, 20 degrees, 22 degrees, 25 degrees, 28 degrees, 30 degrees, 32 degrees, 35 degrees, 38 degrees, 40 degrees, 42 degrees, and the like. The preferred range of the magnitude of the included angle a is 20 to 30 degrees.

Referring to fig. 9 and 10, the edge portions 22 of the front edge 23 and the rear edge 24 are chamfered. The leading edge 23 has a leading edge tail chamfer 231 at the edge portion 22 and the trailing edge 24 has a trailing edge tail chamfer 241 at the edge portion 22. The chamfer angle is arranged, so that the stress at the sharp angle of the blade 2 can be improved, the deformation at the sharp angle of the blade 2 is reduced, and the noise is reduced. Referring to fig. 11, the edge portion 22 of the blade 2 further has a chamfer 221. The provision of the chamfer 221 improves the force at the edge portion 22 of the blade 2 and reduces the deformation at the tip of the blade 2, thereby reducing noise.

The following table shows input power test data of the axial flow fan according to the embodiment of the present invention and the same type of conventional axial flow fan when the same air volume is achieved. Number of slave testsIt can be seen that at 252.51m³Under the wind rate of/min, the input power of the traditional design is about 1003W, while the input power adopting the technical scheme of the invention is about 764W, and the input power is reduced by about 20 percent. The technical scheme of the invention has obvious effect of improving the efficiency of the fan.

Watch 1

	Diameter of blade	Number of revolutions	Air quantity	Input power
					Scheme of the invention	575mm	1058rpm	252.51m3/min	764.14W
Conventional solutions	575mm	1075rpm	252.51m3/min	1003.28W

The following table is noise test data of the axial flow fan adopting the technical scheme of the embodiment of the invention and the conventional axial flow fans of the same type. Fig. 12 is a plot of the test data, and from the data in table two and fig. 12, it can be seen that the noise sound pressure level of the inventive solution is reduced by approximately 2dBA over the conventional solution for the same wind flow rate.

Watch two

As can be seen from the above description of the specific embodiment, in the axial flow fan 100 provided by the present invention, the upper surface of the first blade area 251 of the blade 2, which is close to the hub 1, is a curved surface that is concave downward, so that the load of the blade area can be increased, the air volume can be ensured, and the efficiency can be improved; the upper surface of the second blade area 252 of the blade 2 far away from the hub 1 is an upward convex curved surface, so that the load of the blade area can be reduced, the deformation of the blade area is reduced, the leakage vortex strength of the blade top is reduced, the energy loss is reduced, and the noise can be reduced while the efficiency is improved. The invention also provides an air conditioner outdoor unit which comprises the axial flow fan. The air conditioner outdoor unit provided by the invention has the advantages of the axial flow fan.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.