Semi-open type axial flow fan

Abstract

The utility model discloses a semi-open type axial flow fan which comprises a hub, the hub is provided with a hub outer wall, a set of blades are evenly distributed on the outer circumferential face of the hub outer wall, each blade at least comprises a main wing, a blade root and a blade top, the blade roots and the blade tops are arranged at the two ends of the main wing, and the main wing is provided with ten sections spliced with one another in the blade height direction. Wherein the cross section S0 is a blade root cross section, the cross section S9 is a blade top cross section, the cross sections S1 to S8 are sequentially located between the cross section S0 and the cross section S9, and each cross section is configured according to the cross section diameter, the chord length and the mounting angle. The utility model has the main beneficial effects that the structure is compact, the layout is reasonable, the number of the blades is reasonably set, and under the condition of the same air pressure, the air volume and the efficiency are greatly improved, and the noise is greatly reduced. In addition, compared with the prior art, a wheel flange is omitted, dust accumulation can be avoided, and the cleanliness is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and more specifically, to a semi-open axial flow fan. Background Technology

[0002] Axial flow fans consist of a hub and multiple blades distributed around the hub. The blades have airfoils, leading edges, and trailing edges. Air flows in from the leading edge of the blades, is pressurized by the airfoils, and flows out from the trailing edge of the blades to propel the air to flow in the same direction as the axis. They are commonly used in fans or other ventilation equipment.

[0003] Slight deformation of the blades can easily occur during production or storage and transportation. Due to the high overall structural strength of the thicker blades, it is difficult for them to automatically deform and find a new balance point during operation. This ultimately causes the axial flow fan to vibrate and generate noise during operation. Moreover, the fan usually uses irregularly shaped blades to achieve large air volume and low noise, but the effect is not good and it is impossible to achieve a balance between air volume and noise, resulting in a poor customer experience.

[0004] As disclosed in patent announcement CN217271003U, a seven-bladed high-efficiency, low-noise axial flow fan includes: a hub with a built-in drive motor and an outer wall; a rim; and seven identical composite blades evenly arranged between the outer wall and the rim. Each composite blade includes a main wing and a tip winglet. The main wing includes a blade root fixedly connected to the outer wall of the hub and a blade tip fixedly connected to the rim. The main wing has ten interlocking cross-sections along the blade height direction, where cross-section S0 is the blade root cross-section, cross-section S10 is the blade tip cross-section, and S1 to S9 are located between them. Each cross-section is configured by its cross-sectional diameter, chord length, and installation angle. However, during operation, a large amount of dust accumulates at the rim, causing uneven weight distribution and swaying during operation. Furthermore, the dust accumulation is difficult to clean, time-consuming, and labor-intensive, resulting in significant limitations. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a semi-open axial flow fan.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A semi-open axial flow fan includes a hub with an outer wall. A set of blades is evenly distributed on the outer circumference of the outer wall. Each blade includes at least a main wing and blade roots and tips at its two ends. The main wing has ten interlocking cross-sections along its height direction, where cross-section S0 is the blade root cross-section, cross-section S9 is the blade tip cross-section, and cross-sections S1 to S8 are located between them. Each cross-section is configured by its diameter, chord length, and installation angle.

[0008]

[0009] Preferably, the airfoil of the blade (3) has a geometric shape, formed by smoothly connecting the two-dimensional coordinates of each point on the pressure surface and the suction surface, wherein the two-dimensional coordinates of the pressure surface and the suction surface are respectively:

[0010]

[0011]

[0012]

[0013] Preferably, using the trailing edge axial reference line of the blade root section as a reference, the trailing edge axial offset distances of sections S1 to S9 are as follows:

[0014]

[0015]

[0016] Preferably, each section of the main wing (31) curves forward along the trailing edge in the circumferential direction, with the following curve angles:

[0017]

[0018] Preferably, seven blades (3) are evenly distributed on the outer circumferential surface of the outer wall (2) of the hub. The leading edges of each blade (3) are non-uniformly distributed in the circumferential direction. The two sides of the leading edges form a non-uniform angle α with the center of the hub (1). The non-uniform angle data of each blade (3) are as follows:

[0019] blade Circumferential non-uniform angle (degree) Leaf #1 0 Leaf #2 2.7 Leaf #3 -0.4 Leaf #4 1.8 Leaf #5 -0.8 Blade #6 3.1 Leaf #7 -0.5 .

[0020] The beneficial effects of this invention are mainly reflected in its compact structure, reasonable layout, and optimized number of blades. Furthermore, under the same wind pressure conditions, this invention significantly improves airflow and efficiency while greatly reducing noise. In addition, compared with existing technologies, the elimination of the wheel rim avoids dust accumulation and greatly improves cleanliness. Attached Figure Description

[0021] The technical solution of this utility model will be further described below with reference to the accompanying drawings:

[0022] Figure 1 : A perspective view of a preferred embodiment of the present invention;

[0023] Figure 2 : A structural diagram of the main wing in a preferred embodiment of this utility model;

[0024] Figure 3 : Front view of a preferred embodiment of the present invention. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the specific embodiments shown in the accompanying drawings. However, these embodiments are not limited to the present invention, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present invention.

[0026] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0027] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] like Figures 1 to 3 As shown, this utility model discloses a semi-open axial flow fan, including a hub 1. The hub 1 has an outer wall 2, and a set of blades 3 are evenly distributed on the outer circumferential surface of the outer wall 2. In this embodiment, seven blades 3 are evenly distributed on the outer circumferential surface of the outer wall 2. The leading edges of each blade 3 are non-uniformly distributed in the circumferential direction, and the two sides of the leading edges form a non-uniform angle α with the center of the hub 1. Taking the direction in the same direction as the rotation direction of the hub 1 as a positive value, the non-uniform angle data of each blade 3 are as follows:

[0029] blade Circumferential non-uniform angle (degree) Leaf #1 0 Leaf #2 2.7 Leaf #3 -0.4 Leaf #4 1.8 Leaf #5 -0.8 Blade #6 3.1 Leaf #7 -0.5 .

[0030] The blade arrangement described above is a preferred embodiment of this utility model. Of course, the number of blades 3 can also be other, and adjustments can be made according to actual needs. All of these fall within the protection scope of this utility model and will not be elaborated further here. Compared with the prior art where the blade leading edge is axially uniformly distributed, this design can significantly reduce resistance under the same rotational speed, resulting in a significant increase in airflow and efficiency.

[0031] Furthermore, in this utility model, the blade 3 includes at least a main wing 31 and blade roots 32 and blade tips 33 disposed at both ends thereon. The main wing 31 is provided with ten interlocking cross sections along the blade height direction, wherein cross section S0 is the blade root cross section, cross section S9 is the blade tip cross section, and cross sections S1 to S8 are located between the two in sequence. Each cross section is configured by the cross section diameter, chord length, and installation angle.

[0032]

[0033] Furthermore, the airfoil of blade 3 is a composite airfoil, based on the NACA-6407 airfoil, with a portion of the trailing edge removed to give the airfoil a geometric shape. It is formed by smoothly connecting the two-dimensional coordinates of points on the pressure and suction surfaces. The two-dimensional coordinates of the pressure and suction surfaces are as follows:

[0034]

[0035]

[0036]

[0037] Using the trailing edge axial reference line of the blade root section as a reference, the trailing edge axial offset distances of sections S1 to S9 are as follows:

[0038]

[0039] Each section of the main wing 31 curves forward along the trailing edge in the circumferential direction, with the following curve angles:

[0040]

[0041] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0042] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementations or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

Claims

1. A semi-open axial fan, including a hub (1), characterized in that: The hub (1) has a hub outer wall (2), and a set of blades (3) are evenly distributed on the outer circumference of the hub outer wall (2). The blades (3) include at least a main wing (31) and blade roots (32) and blade tips (33) at both ends thereon. The main wing (31) has ten interlocking cross sections along the blade height direction, wherein cross section S0 is the blade root cross section, cross section S9 is the blade tip cross section, and cross sections S1 to S8 are located between the two in sequence. Each cross section is configured by the cross section diameter, chord length and installation angle.

2. The semi-open axial flow fan according to claim 1, characterized in that: The airfoil of the blade (3) has a geometric shape, which is formed by smoothly connecting the two-dimensional coordinates of each point on the pressure surface and the suction surface. The two-dimensional coordinates of the pressure surface and the suction surface are as follows:

3. The semi-open axial flow fan according to claim 1, characterized in that: Using the trailing edge axial reference line of the blade root section as a reference, the trailing edge axial offset distances of sections S1 to S9 are as follows:

4. The semi-open axial flow fan according to claim 1, characterized in that: Each section of the main wing (31) curves forward along the trailing edge in the circumferential direction, with the following forward curvature angles:

5. The semi-open axial flow fan according to claim 1, characterized in that: Seven blades (3) are evenly distributed on the outer circumferential surface of the outer wall (2) of the hub. The leading edges of each blade (3) are non-uniformly distributed in the circumferential direction. The two sides of the leading edges form a non-uniform angle α with the center of the hub (1). The non-uniform angle data of each blade (3) are as follows: 。

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