Fan blade unit and cross-flow fan blade equipped with the same

Abstract

This invention relates to a wind turbine unit and a cross-flow wind turbine blade having the same. The wind turbine unit includes: a first connecting ring and a second connecting ring spaced apart and coaxially arranged in a first direction; and a blade assembly including a plurality of blades arranged around the first direction, with the plurality of blades spaced apart from each other circumferentially. Each blade's opposite ends in the first direction are connected to the first connecting ring and the second connecting ring, respectively. The orthographic projections of each blade and the second connecting ring on a first virtual plane overlap. In this wind turbine unit, the first and second connecting rings connect the two ends of all the wind turbine blades into one unit, effectively preventing deformation of isolated blades during production and placement. Because the orthographic projections of each blade and the second connecting ring on a plane perpendicular to the first direction overlap, the joint has a large cross-sectional area, resulting in greater connection strength and thus improving the overall strength of the wind turbine unit.

Description

Technical Field

[0001] The present invention relates to the technical field of fan manufacturing, and in particular to a fan blade unit and a cross-flow fan blade provided with the fan blade unit. Background Art

[0002] Crossflow blades are widely used in various production and living equipment with cooling, heat dissipation, ventilation and air exchange functions because of their unlimited axial length, the length can be selected arbitrarily according to different usage needs, the airflow can reach a long distance, there is no turbulence, and the air output is uniform. Taking air conditioners as an example, crossflow blades are important components used to guide air in air conditioners. When the crossflow blades rotate, the airflow flows in from the air inlet of the air duct, passes through the evaporator for heat exchange, and is blown out from the air outlet of the air duct to achieve the air outlet of the air conditioner.

[0003] The existing crossflow fan mainly includes three structural parts: the fan unit, the end cover and the shaft cover. Each structural part is produced by a separate set of molds, and then multiple middle-section fan blades, the end cover and the shaft cover are gradually welded by ultrasonic to form a complete crossflow fan. However, due to structural defects, the current fan unit is easily damaged due to collision with other parts during placement. Summary of the invention

[0004] Based on this, it is necessary to provide a fan unit and a cross-flow fan provided with the fan unit which can effectively prevent the cross-flow fan blade from being damaged in order to solve the problem that the cross-flow fan blade is easily damaged.

[0005] A fan blade unit, the fan blade unit comprising:

[0006] A first connecting ring and a second connecting ring spaced apart and coaxially arranged in a first direction; and

[0007] a blade assembly, comprising a plurality of blades arranged around the first direction, wherein the plurality of blades are spaced apart from each other along the circumferential direction, and opposite ends of each blade in the first direction are respectively connected to the first connecting ring and the second connecting ring;

[0008] Wherein, the orthographic projections of each of the blades and the second connecting ring on the first virtual plane have an overlapping area;

[0009] The first direction is perpendicular to the first virtual plane.

[0010] In one embodiment, the orthographic projection of the blade on the first virtual plane has a first edge and a second edge along the radial direction of the blade assembly; the first edges of a plurality of the blades are located on a first concentric circle, and the second edges of a plurality of the blades are located on a second concentric circle;

[0011] The first concentric circle and the second concentric circle are cocentrically arranged, and the diameter of the first concentric circle is smaller than the diameter of the second concentric circle;

[0012] The inner diameter of the second connecting ring is larger than the diameter of the first concentric circle and smaller than the diameter of the second concentric circle, and the outer diameter of the second connecting ring is larger than the diameter of the second concentric circle.

[0013] In one embodiment, the first concentric circle and the second concentric circle have a first center;

[0014] The orthographic projections of the first connecting ring and the second connecting ring on the first virtual plane have a second center; the first center coincides with the second center.

[0015] In one embodiment, the inner contour of the second connecting ring is circular, and the outer contour of the second connecting ring is non-circular.

[0016] In one embodiment, the outer contour of the second connecting ring extends in a wave shape along the circumferential direction to form a plurality of wave crests and wave troughs that are alternately arranged.

[0017] In one embodiment, the wave crest is in an arc shape.

[0018] In one of the embodiments, in the radial direction of the wind blade unit, the wave troughs are arranged corresponding to the blades, and each of the wave peaks is arranged correspondingly between two adjacent blades.

[0019] In one embodiment, an end surface of the blade away from the first connecting ring and an end surface of the second connecting ring away from the first connecting ring are located in the same plane.

[0020] In one embodiment, the orthographic projection of the second connecting ring on the first connecting ring is completely located on the first connecting ring.

[0021] In one of the embodiments, an outer contour of an orthographic projection of the second connecting ring on the first connecting ring completely coincides with an outer contour of the second connecting ring.

[0022] In one embodiment, the first connecting ring includes a first connecting portion and a second connecting portion, the first connecting portion and the second connecting portion are stacked in the first direction, the blade assembly is connected to the first connecting portion, the second connecting portion is located on a side of the first connecting portion away from the blade assembly, the outer diameter of the second connecting portion is smaller than the outer diameter of the first connecting portion, and the second connecting portion is provided with a plurality of blade mounting grooves, the plurality of blade mounting grooves are arranged at intervals from each other along the circumference of the second connecting portion, and each of the blade mounting grooves is connected to two opposite surfaces of the second connecting portion in the first direction;

[0023] The orthographic projection of each blade on the first connecting ring is located in one of the blade mounting grooves, and the orthographic projection of the second connecting ring on the first connecting ring is located in an area where the first connecting portion is not connected to the second connecting portion.

[0024] A crossflow fan blade comprises the above-mentioned fan blade unit.

[0025] In one embodiment, a plurality of the fan blade units are connected in sequence along a first direction, and among two adjacent fan blade units, one of the fan blade units is connected to the first connecting ring of the other fan blade unit by means of a second connecting ring and a blade assembly.

[0026] In the above-mentioned fan blade unit, the two ends of the blade assembly of the fan blade unit are respectively provided with a first connecting ring and a second connecting ring, and the first connecting ring and the second connecting ring connect the two ends of all the fan blades into one body, thereby effectively preventing the deformation of isolated blades during production and placement. Since the orthographic projections of each blade and the second connecting ring on the plane perpendicular to the first direction have an overlapping area, the junction of the two has a larger cross-sectional area, and thus has a larger connection strength, thereby improving the overall strength of the fan blade unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a crossflow fan blade according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 A schematic structural diagram of a fan blade unit of a crossflow fan blade is shown;

[0029] Figure 3 for Figure 2 A transverse cross-sectional view of the fan blade unit shown;

[0030] Figure 4 for Figure 2 A longitudinal sectional view of the fan blade unit shown;

[0031] Figure 5 for Figure 2 A schematic diagram of a first connecting ring of a fan blade unit is shown;

[0032] Figure 6 A schematic diagram of the fan blade units connected to each other according to an embodiment of the present invention;

[0033] Figure 7 FIG. 1 is a schematic diagram of a contact surface of a fan blade unit during welding according to an embodiment of the present invention.

[0034] Description of reference numerals:

[0035] 100, crossflow fan blade; 20, shaft cover; 40, end cover; 60, fan blade unit; 61, first connecting ring; 612, first connecting part; 614, second connecting part; 6141, blade mounting groove; 63, second connecting ring; 65, blade assembly; 652, blade. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying 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 the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0042] See also Figure 1 and Figure 2 , Figure 1 FIG. 1 shows a schematic diagram of the structure of a crossflow fan blade in an embodiment of the present invention. Figure 2 for Figure 1 A schematic structural diagram of a fan blade unit of a crossflow fan blade is shown.

[0043] The embodiment of the present invention provides a crossflow fan blade 100, which is used to be installed in an air conditioner or other device, and the crossflow fan blade 100 can rotate around its own central axis to form an airflow. Specifically, the crossflow fan blade 100 is generally a hollow cylindrical structure, including a shaft cover 20, an end cover 40 and a plurality of fan blade units 60, and the plurality of fan blade units 60 are sequentially connected by ultrasonic welding or the like, and the shaft cover 20 and the end cover 40 are arranged at the head and tail ends of the crossflow fan blade 100 by ultrasonic welding or the like.

[0044] As described in the background technology, the shaft cover 20, the end cover 40 and the fan blade unit 60 are produced separately using a set of molds, and the produced shaft cover 20, the end cover 40 and the plurality of fan blade units 60 are transported to the welding device and welded into a whole. The existing fan blade unit usually includes a fixed disc and a plurality of blades. The fixed disc is roughly annular. The plurality of blades are arranged on one side of the fixed disc and are distributed along the circumference of the fixed disc. The end of the blade away from the fixed disc is an open structure. Each blade is separated from each other and independently arranged. Therefore, during the production and placement process, collisions between adjacent blades and between blades and other parts are inevitable, resulting in deformation or even damage of the blades. Moreover, the plurality of blades are also prone to deformation during the production and placement process after production.

[0045] In addition, during the use of the crossflow fan blade 100, each welding part is very easy to be damaged. The inventor found in the research that the main reason for the easy damage of each welding part is that the connection of two adjacent fan blade units in the prior art is achieved by each blade of one fan blade unit and the fixed disk of the other fan blade unit through separate independent welding. Since the area of ​​the blade end is very small, the contact surface of the two fan blade units is too small, which easily leads to the welding being not firm and damaged, and then the fan blade breaks.

[0046] In order to solve the above problems, the fan blade unit 60 of the present invention includes a first connecting ring 61, a second connecting ring 63 and a blade assembly 65. The first connecting ring 61 and the second connecting ring 63 are coaxial and spaced in the first direction, and the blade assembly 65 includes a plurality of blades 652, which are arranged around the first direction and spaced from each other along the circumferential direction, and each blade 652 is connected to the first connecting ring 61 and the second connecting ring 63 at opposite ends in the first direction. The orthographic projections of each blade 652 and the second connecting ring 63 on the first virtual plane have an overlapping area, and one fan blade unit 60 can be connected to the first connecting ring 61 of another fan blade unit 60 through the second connecting ring 63.

[0047] It should be noted that the first virtual plane is any plane perpendicular to the first direction.

[0048] In this way, the two ends of the blade assembly 65 of the fan blade unit 60 are respectively provided with a first connecting ring 61 and a second connecting ring 63, and the first connecting ring 61 and the second connecting ring 63 connect the two ends of all the blades 652 into one body, thereby effectively preventing the deformation of the isolated blades 652 during the production and placement process. Since the orthographic projections of each blade 652 and the second connecting ring 63 on the plane perpendicular to the first direction have an overlapping area, compared with the tangential arrangement of the blade and the connecting ring in the prior art, the junction of the blade 652 and the second connecting ring 63 of the present invention has a larger cross-sectional area, and thus has a greater strength, thereby improving the overall strength of the fan blade unit 60. Moreover, since one of the two adjacent fan blade units 60 can be connected to the first connecting ring 61 of the other fan blade unit 60 through the second connecting ring 63, the contact area of ​​the adjacent fan blade units 60 is increased, thereby enhancing the overall firmness of the crossflow fan blade 100 and reducing the breakage rate of the crossflow fan blade 100.

[0049] Combination Figure 3 , Figure 4 as well as Figure 5 As shown, Figure 3 FIG. 4 shows a transverse cross-sectional view of a fan blade unit in an embodiment of the present invention, Figure 4 FIG. 2 shows a longitudinal cross-sectional view of a fan blade unit in an embodiment of the present invention, Figure 5 A schematic diagram of a first connecting ring of a fan blade unit in an embodiment of the present invention is shown.

[0050] In some embodiments, the first connecting ring 61 is a hollow ring structure, and the central axis direction of the first connecting ring 61 is the first direction mentioned in the present invention.

[0051] The blade assembly 65 is integrally formed with the first connecting ring 61, one end of each blade 652 of the blade assembly 65 is connected to the first connecting ring 61, and the other end of the blade 652 extends along the first direction away from the first connecting ring 61 to form a long strip structure, and the positive projection of each blade 652 on a plane perpendicular to the first direction is an arc shape. It can be understood that the shape and number of the blades 652 are not limited, and the gaps between each two adjacent blades 652 can be the same or different, and can be set as needed to meet different requirements.

[0052] Furthermore, if Figure 3 As shown, the positive projection of the blade 652 on the first virtual plane has a relative first edge and a second edge along the radial direction of the blade assembly 65, the first edge of each blade 652 is located on a first concentric circle with a diameter D1, and the second edge of each blade 652 is located on a second concentric circle with a diameter D2, the first concentric circle and the second concentric circle are concentrically arranged, and the diameter D1 of the first concentric circle is smaller than the diameter D2 of the second concentric circle.

[0053] The second connecting ring 63 is a hollow ring structure, and the central axis of the second connecting ring 63 coincides with the central axis of the first connecting ring 61 so as to be coaxially arranged with the first connecting ring 61. The inner diameter of the second connecting ring 63 is larger than the diameter D1 of the first concentric circle and smaller than the diameter D2 of the second concentric circle, and the outer diameter of the second connecting ring 63 is larger than the diameter D2 of the first concentric circle.

[0054] Preferably in one embodiment, Figure 3 As shown, the inner contour of the second connecting ring 63 can define an inscribed circle with a diameter of D3, and the outer contour of the second connecting ring 63 can define a circumscribed circle with a diameter of D4; the size relationship between D1, D2, D3 and D4 is: D1 <D3<D2<D4。

[0055] In this way, the cross-sectional area of ​​the joint between the blade 652 and the second connecting ring 63 is larger, and both have higher structural strength, thereby ensuring the firmness of the connection between the second connecting ring 63 and the blade 652 and further enhancing the overall strength.

[0056] Further, the first concentric circle and the second concentric circle have a first center, the orthographic projections of the first connecting ring 61 and the second connecting ring 63 on the first virtual plane have a second center, the first center coincides with the second center, and the outer diameter of the second connecting ring 63 is not greater than the outer diameter of the first connecting ring 61, and the orthographic projection of the second connecting ring 63 on the first connecting ring 61 is completely located on the first connecting ring 61. In this way, the first connecting ring 61, the blade assembly 65 and the second connecting ring 63 are coaxially arranged, and after the two fan blade units 60 are connected to each other, in the radial direction of the fan blade unit 60, the first connecting ring 61 will not protrude from the second connecting ring 63, thereby ensuring the consistency of the packaging size of the crossflow fan blade 100.

[0057] Preferably, in one embodiment, the shape of the outer contour of the first connecting ring 61 is completely identical to the shape of the outer contour of the second connecting ring 63 , and the outer contour of the orthographic projection on the first connecting ring 61 completely coincides with the outer contour of the second connecting ring 63 .

[0058] Specifically, in some embodiments, the inner contour and the outer contour of the second connecting ring 63 are both circular, and accordingly, the outer contour of the first connecting ring 61 is also preferably circular. In other embodiments, the inner contour of the second connecting ring 63 is circular, and the outer contour of the second connecting ring 63 is non-circular, and accordingly, the outer contour of the first connecting ring 61 is also non-circular in shape, which is the same as the outer contour of the second connecting ring 63.

[0059] Preferably, in one embodiment, the outer contour of the second connecting ring 63 extends in a wavy shape along the circumferential direction and has arc-shaped crests and troughs arranged alternately, and an arc-shaped crest is arranged between two adjacent troughs. In the radial direction of the fan blade unit 60, the troughs are arranged corresponding to the blades 652, and the arc-shaped crests correspond to the space between two adjacent blades 652. Correspondingly, the outer contour of the first connecting ring 61 also extends in a wavy shape along the circumferential direction and has arc-shaped crests and troughs arranged alternately. It can be understood that since the spacing between the blades 652 is not equal, the radii of the arc-shaped crests formed by the outer contour of the second connecting ring 63 are also not equal.

[0060] Thus, the outer contour of the second connecting ring 63 can effectively reduce the rotation noise generated when the crossflow fan blade 100 rotates, and improve the noise quality. It can be understood that the outer contour of the second connecting ring 63 is not limited to this, and different shapes can be selected as needed.

[0061] Furthermore, the end surface of the blade 652 away from the first connecting ring 61 and the end surface of the second connecting ring 63 away from the first connecting ring 61 are located in the same plane, that is, Figure 5 As shown, the distance H0 between the end surface of the blade 652 away from the first connecting ring 61 and the first connecting ring 61 is equal to the distance H1 between the end surface of the second connecting ring 63 away from the first connecting ring 61 and the first connecting ring 61 .

[0062] In this way, the end face of the blade 652 is flush with the end face of the second connecting ring 63, and the second connecting ring 63 of one fan unit 60 can contact the first connecting ring 61 of another fan unit 60 at the same time as the end face of the blade 652, thereby enlarging the contact area between the two fan units 60, increasing the connection strength of the two fan units 60, and protecting the blade 652 from wear.

[0063] Thus, the plurality of blade units 60 are sequentially connected along the first direction to form a cross-flow blade 100 , and among two adjacent blade units 60 , the first connecting ring 61 of one blade unit 60 is welded to the second connecting ring 63 of the other blade unit 60 .

[0064] Combination Figure 6 and Figure 7 , Figure 6 FIG. 1 is a schematic diagram showing the interconnection of the fan blade units 60 in one embodiment of the present invention. Figure 7 FIG. 1 is a schematic diagram of a contact surface of a fan blade unit 60 during welding according to an embodiment of the present invention.

[0065] In one embodiment, the first connecting ring 61 includes a first connecting portion 612 and a second connecting portion 614 stacked in a first direction. The blade assembly 65 is connected to a side end surface of the first connecting portion 612 away from the second connecting portion 614. The outer diameter of the second connecting portion 614 is smaller than the outer diameter of the first connecting portion 612. The second connecting portion 614 is provided with a blade mounting groove 6141 for connecting the blade assembly 65 of another fan blade unit 60. A plurality of blade mounting grooves 6141 are arranged at intervals along the circumferential direction. Each blade mounting groove 6141 extends inward from the outer edge of the second connecting portion 614 and connects two opposite surfaces of the second connecting portion 614 in the first direction. The orthographic projection of each blade 652 on the first connecting ring 61 is located in a blade mounting groove 6141, and the orthographic projection of the second connecting ring 63 on the first connecting ring 61 is located in the area where the first connecting portion 612 is not connected to the second connecting portion 614.

[0066] So, like Figure 6 As shown, when the two blade units 60 are connected to each other, each blade 652 of the blade unit 60 on the right side is inserted into a blade installation groove 6141 of the blade unit 60 on the left side, and abuts against the first connection portion 612 of the first connection ring 61 of the blade unit 60 on the left side. At the same time, the first connection portion 612 of the second connection ring 63 of the blade unit 60 on the right side also contacts the area where the first connection portion 612 of the first connection ring 61 of the blade unit 60 on the left side surrounds the second connection portion 614. Therefore, the two blade units 60 connected to each other contact each other through the blades 652 and the connection ring, so as to have a larger contact area.

[0067] The two ends of the blade assembly 65 of the above-mentioned blade unit 60 and the crossflow blade 100 equipped therewith are connected to each other as a whole through the first connecting ring 61 and the second connecting ring 63, respectively, so that the blade assembly 65 has a high overall strength, which effectively prevents the blade 652 from being damaged or deformed during the placement of the blade unit 60. In addition, the two interconnected blade units 60 have a large contact area, thereby increasing the firmness of the welding point between the two, improving the production efficiency of the crossflow blade 100, further enhancing the overall strength of the crossflow blade 100, extending the service life of the crossflow blade 100, and reducing the after-sales failure rate of the crossflow blade 100.

[0068] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A fan blade unit, characterized in that: The fan blade unit comprises: A first connecting ring (61) and a second connecting ring (63) spaced apart and coaxially arranged in a first direction; and A blade assembly (65) comprising a plurality of blades (652) arranged around the first direction, wherein the plurality of blades (652) are arranged at intervals from one another along the circumferential direction, and each blade (652) is respectively connected to the first connecting ring (61) and the second connecting ring (63) at two opposite ends in the first direction; The orthographic projections of each blade (652) and the second connecting ring (63) on the first virtual plane have an overlapping area; the orthographic projection of the blade (652) on the first virtual plane has a first edge and a second edge along the radial direction of the blade assembly (65); the first edges of a plurality of blades are located on a first concentric circle, the second edges of a plurality of blades are located on a second concentric circle, the first concentric circle and the second concentric circle have a first center, and the diameter of the first concentric circle is smaller than the diameter of the second concentric circle; the inner diameter of the second connecting ring (63) is larger than the diameter of the first concentric circle and smaller than the diameter of the second concentric circle, the outer diameter of the second connecting ring (63) is larger than the diameter of the second concentric circle, the orthographic projections of the first connecting ring (61) and the second connecting ring (63) on the first virtual plane have a second center; the first center coincides with the second center; The first direction is perpendicular to the first virtual plane.

2. The fan blade unit according to claim 1, characterized in that: The inner contour of the second connecting ring (63) is circular, and the outer contour of the second connecting ring (63) is non-circular.

3. The fan blade unit according to claim 2, characterized in that: The outer contour of the second connecting ring (63) extends in a wave shape along the circumferential direction to form a plurality of alternately arranged wave crests and wave troughs.

4. The fan blade unit according to claim 3, characterized in that: The wave crest is in an arc shape.

5. The fan blade unit according to claim 3, characterized in that: In the radial direction of the wind blade unit, the wave trough is arranged corresponding to the blade (652), and each wave crest is arranged correspondingly between two adjacent blades (652).

6. The fan blade unit according to claim 1, characterized in that: An end surface of one side of the blade (652) away from the first connecting ring (61) and an end surface of one side of the second connecting ring (63) away from the first connecting ring (61) are located in the same plane.

7. The fan blade unit according to claim 1, characterized in that: The orthographic projection of the second connecting ring (63) on the first connecting ring (61) is completely located on the first connecting ring (61).

8. The fan blade unit according to claim 7, characterized in that: The outer contour of the orthographic projection of the second connecting ring (63) on the first connecting ring (61) completely coincides with the outer contour of the second connecting ring (63).

9. The fan blade unit according to claim 7, characterized in that: The first connecting ring (61) comprises a first connecting portion (612) and a second connecting portion (614), the first connecting portion (612) and the second connecting portion (614) being stacked in the first direction, the blade assembly (65) being connected to the first connecting portion (612), the second connecting portion (614) being located on a side of the first connecting portion (612) away from the blade assembly (65), the outer diameter of the second connecting portion (614) being smaller than the outer diameter of the first connecting portion (612), the second connecting portion (614) being provided with a plurality of blade mounting grooves (6141), the plurality of blade mounting grooves (6141) being arranged at intervals from each other along the circumference of the second connecting portion (614), and each of the blade mounting grooves (6141) being connected to two opposite surfaces of the second connecting portion (614) in the first direction; The orthographic projection of each blade (652) on the first connecting ring (61) is located in one of the blade mounting grooves (6141), and the orthographic projection of the second connecting ring (63) on the first connecting ring (61) is located in an area where the first connecting portion (612) is not connected to the second connecting portion (614).

10. A crossflow fan blade, characterized in that: The invention comprises a plurality of wind blade units according to any one of claims 1 to 9.

11. The crossflow fan blade according to claim 10, characterized in that: The plurality of wind blade units are connected in sequence along a first direction, and among two adjacent wind blade units, one of the wind blade units is connected to the first connecting ring (61) of the other wind blade unit by means of a second connecting ring (63) and a blade assembly (65).

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