Fan blade, fan and air blowing device

Abstract

A fan blade, comprising a hub (101) and blades (102), wherein the blades are connected to the hub; each blade comprises a first segment (11) and a second segment (12), and a hollow region (10a) is provided between the first segment and the second segment; a reference cylindrical surface (103) is configured around the axis of the hub and a spatial intersection line of the reference cylindrical surface and each blade is defined as a blade profile; the blade profile of the first segment is configured to protrude away from the rotation direction of the fan blade, and the blade profile of the second segment is configured to protrude away from the rotation direction of the fan blade. Also provided are a fan and an air blowing device. The working capacity of the fan blade at a same rotation speed can be improved, thus increasing the air supply amount thereof.

Description

Fans, fans and blowing equipment

[0001] This application claims priority to Chinese patent application No. 202323667442.5 filed on December 29, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of fan blades, and in particular to a fan blade, a fan and a blowing device. Background Art

[0003] Air conditioners are widely used in our daily lives. Axial-flow fans, such as floor fans, are particularly popular due to their high wind power and wide air distribution range. However, current fan blades are typically simple straight or curved, resulting in insufficient airflow at lower speeds, making them difficult to meet user needs. Technical issues

[0004] The main purpose of this application is to provide a fan blade, aiming to improve the work capacity of the fan blade under the same rotational speed conditions, thereby increasing its air supply. Technical Solutions

[0005] To achieve the above objectives, the fan blades proposed in this application include:

[0006] wheel hubs; and

[0007] a blade connected to the hub, the blade comprising a first segment and a second segment, with a hollow area between the first segment and the second segment;

[0008] A reference cylindrical surface is constructed around the axis of the hub, and the spatial intersection line between the reference cylindrical surface and the blade is defined as the blade shape. The blade shape of the first segment is convexly set away from the rotation direction of the fan blade, and the blade shape of the second segment is convexly set away from the rotation direction of the fan blade.

[0009] In one embodiment, a ratio of the chord length of the blade profile of the first segment to the chord length of the blade profile of the second segment ranges from 0.8 to 1.2.

[0010] In one embodiment, a ratio of the curvature of the blade profile of the first segment to the curvature of the blade profile of the second segment ranges from 0.8 to 1.2.

[0011] In one embodiment, a reference projection plane is defined that passes through the axis of the hub and the midpoint of the hollow area at the same time, and the ratio of the overlapping length of the projections of the blade profile of the first segment and the blade profile of the second segment on the reference projection plane to the projection length of the blade profile of the first segment is less than or equal to 40%.

[0012] In one embodiment, in the circumferential direction of the hub, a relative pitch between the blade profile of the first segment and the blade profile of the second segment ranges from 0.7 to 1.

[0013] In one embodiment, in the air intake direction of the fan blade, the first segment is located upstream of the second segment; in the rotation direction of the fan blade, the blade profile of the second segment is located upstream of the first segment, and the suction surface of the blade profile of the first segment is arranged adjacent to the pressure surface of the blade profile of the second segment.

[0014] In one embodiment, the blade profile of the first segment and the blade profile of the second segment form a tandem blade form.

[0015] In one embodiment, the inner end of the first segment and the inner end of the second segment are respectively connected to the hub, and the hollow area is defined between the first segment, the second segment and the hub.

[0016] In one embodiment, the inner end of the first segment is connected to the side edge of the second segment, and the inner end of the second segment is connected to the hub.

[0017] In one embodiment, the inner end of the first segment and the inner end of the second segment are connected and are simultaneously connected to the hub.

[0018] In one embodiment, the blade further includes a bridging segment connecting an outer end of the first segment and an outer end of the second segment, and a smooth transition is formed between the first segment, the bridging segment, and the second segment.

[0019] The present application also proposes a fan, comprising the aforementioned fan blades.

[0020] The present application also proposes a blowing device, comprising the aforementioned fan blades or blower. Beneficial effects

[0021] In the technical solution of the present application, because the blade profiles of the first and second segments protrude in the same direction, that is, the blade profiles of the first and second segments both protrude away from the direction of rotation of the fan blade, the work done by the first and second segments can be superimposed, thereby increasing the total work capacity of the blade and improving the work capacity of the fan blade under the same speed conditions, thereby increasing the air flow rate of the fan blade. On the other hand, a fan using the fan blades of the present application can operate at a lower speed and power to meet the same air flow requirement, thereby helping to reduce the energy consumption of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0023] FIG1 is a schematic structural diagram of a fan blade according to an embodiment of the present application;

[0024] FIG2 is a schematic diagram of a blade of the fan blade in FIG1 intersecting with a reference cylindrical surface to form a set of blade profiles;

[0025] FIG3 is a schematic diagram of the fan blades in FIG2 intersecting with a plurality of different reference cylindrical surfaces to form multiple groups of blade profiles;

[0026] FIG4 is a schematic diagram of the structure of the same set of blades in FIG3 after being unfolded into a planar state;

[0027] FIG5 is a schematic diagram of the elementary-level velocity triangle analysis of the two blade profiles in FIG4 ;

[0028] FIG6 is a diagram showing the power-air volume relationship of the fan blade shown in FIG1 and a fan blade in the prior art;

[0029] FIG7 is a schematic structural diagram of another embodiment of a fan blade of the present application;

[0030] FIG8 is a schematic structural diagram of another embodiment of the fan blade of the present application.

[0031] Description of Figure Numbers:

[0032] Reference numerals: Reference numerals: 101 hub 10e chord line 102 blade 10f pressure surface 103 reference cylindrical surface 10g suction surface 10a hollow area 11 first segment 10b leading edge 12 second segment 10c trailing edge 13 bridge segment 10d central axis

[0033] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0034] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0035] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In this application, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0038] The present application proposes a fan blade. Referring to Figures 1 to 8, in some embodiments of the present application, the fan blade includes:

[0039] a wheel hub 101; and

[0040] The blade 102 is connected to the hub 101. The blade 102 includes a first segment 11 and a second segment 12. At least parts of the first segment 11 and the second segment 12 are spaced apart in the circumferential and / or axial direction of the hub 101. A hollow area 10a is defined between the first segment 11 and the second segment 12.

[0041] A reference cylindrical surface 103 is constructed around the axis of the hub 101, and the spatial intersection line of the reference cylindrical surface 103 and the blade 102 is defined as the blade profile. The blade profile of the first segment 11 is convexly set away from the rotation direction of the fan blade, and the blade profile of the second segment 12 is convexly set away from the rotation direction of the fan blade.

[0042] Specifically, please refer to Figure 4, which is a schematic diagram of the structure of the same set of blades in Figure 3 after being unfolded into a planar state. In this embodiment, in the direction of rotation of the fan blade, the second segment 12 is located upstream of the first segment 11, and in the air intake direction of the fan blade, the first segment 11 is located upstream of the second segment 12. Of course, in other embodiments, in the air intake direction of the fan blade, the second segment 12 may be located upstream of the first segment 11, or the two may be arranged side by side; in the direction of rotation of the fan blade, the first segment 11 may be located upstream of the second segment 12, or the two may be arranged side by side.

[0043] In Figure 4, the blade profiles of the first segment 11 and the second segment 12 both have a trailing edge 10c and a leading edge 10b arranged relative to each other along the rotation direction of the fan blade. In the wind inlet direction of the fan blade, the airflow flows in from the leading edge 10b of the blade profile and flows out from the trailing edge 10c of the blade profile; the line between the midpoint of the leading edge 10b and the midpoint of the trailing edge 10c of the blade profile is its chord 10e. It can be seen that regardless of the first segment 11 or the second segment 12, the central axis 10d of the blade profile is located on the side of its chord 10e that is away from the rotation direction of the fan blade, which means that both blade profiles are protruding away from the rotation direction of the fan blade, that is, the component of the protruding direction of the blade profile in the rotation direction of the fan blade is set in the opposite direction to the rotation direction of the fan blade.

[0044] Further, please refer to Figure 5 and analyze the blade profiles of the first segment 11 and the second segment 12 respectively using the primitive-level velocity triangle. The relative velocity of the air flowing through the first segment 11 with its leading edge 10b is defined as W11, and the relative velocity with its trailing edge 10c is defined as W12. ΔW1u extends along the tangential direction of the fan blade rotation direction and is used to represent the speed change from W11 to W12. Similarly, the relative velocity of the air flowing through the first segment 11 with its leading edge 10b can be defined as W21, and the relative velocity with its trailing edge 10c is defined as W22. ΔW2u extends along the tangential direction of the fan blade rotation direction and is used to represent the speed change from W21 to W22.

[0045] As can be seen from Figure 5, in the technical solution of the present application, since the blade profiles of the first segment 11 and the second segment 12 are raised in the same direction, that is, the blade profiles of the first segment 11 and the second segment 12 are both raised away from the rotation direction of the fan blade, ΔW1u and ΔW2u are both in the same direction as the rotation direction of the fan blade, so that the work done by the first segment 11 and the second segment 12 can be superimposed, thereby improving the total work capacity of the blade 102 and improving the work capacity of the fan blade under the same speed conditions, thereby increasing the air supply of the fan blade. On the other hand, the fan fan using the fan blade of the present application can operate at a lower speed and power to meet the same air supply requirement, which is conducive to reducing the energy consumption of the fan.

[0046] Specifically, see Figure 6, which shows the power-air volume relationship between the fan blade shown in Figure 1 and the prior art fan blade. The blade 102 of the prior art fan blade is a simple curved plate structure. As can be seen from Figure 6, under the same air volume conditions, the power required by the fan blade of the present application is lower than that of the prior art.

[0047] It is worth mentioning that in this embodiment, the maximum thickness dimension of the leading edge 10b of the blade profile is greater than the maximum thickness dimension of the trailing edge 10c, that is, the blade profile has the characteristics of a thick leading edge and a thin trailing edge 10c. This is conducive to improving the flow field on the first segment 11 and the second segment 12, thereby reducing the aerodynamic noise of the fan blade. It should be noted that the thickness dimension of the blade profile refers to the width dimension of the blade profile in a direction perpendicular to its central axis 10d. Of course, in other embodiments, the maximum thickness dimensions of the leading edge and trailing edge 10c of the blade profile may be consistent, or the maximum thickness dimension of the leading edge may be smaller than the maximum thickness dimension of the trailing edge 10c.

[0048] It can be understood that at least parts of the first segment 11 and the second segment 12 are spaced apart in the circumferential and / or axial direction of the hub 101. This may mean that at least parts of the first segment 11 and the second segment 12 are spaced apart only in the axial direction of the hub 101. In this case, the first segment 11 and the second segment 12 are arranged opposite to each other in the axial direction of the hub 101, and the corresponding hollow area 10a has a certain thickness; it may also mean that at least parts of the first segment 11 and the second segment 12 are spaced apart only in the circumferential direction of the hub 101. In this case, the first segment 11 and the second segment 12 are arranged opposite to each other in the circumferential direction of the hub 101, and the corresponding hollow area 10a has a certain width; it may also mean that at least parts of the first segment 11 and the second segment 12 are spaced apart along both the axial and circumferential directions of the hub 101. In this case, the first segment 11 and the second segment 12 are staggered on the hub 101.

[0049] The first segment 11 and the second segment 12 enclose a hollow area 10a, which means that the first segment 11 and the second segment 12 together enclose an annular structure, and the hollow area 10a is the center of the annular structure. The annular structure enclosed by the first segment 11 and the second segment 12 can be either a closed annular structure or a non-closed annular structure. It should be noted that the so-called closed annular structure means that the first segment 11 and the second segment 12 are closed and connected, and the periphery of the hollow area 10a is continuously connected without a gap. For example, referring to Figure 1, in one embodiment, the blade 102 also includes a bridging segment 13, which connects the outer end of the first segment 11 and the outer end of the second segment 12, and the first segment 11, the bridging segment 13 and the second segment 12 have a smooth transition, and the hollow area 10a is defined between the first segment 11, the second segment 12, the bridging segment 13 and the hub 101. That is, the outer end of the first segment 11 and the outer end of the second segment 12 are connected by a curved surface transition of the bridging segment 13, so that the first segment 11 and the second segment 12 are connected by a curved surface transition, thereby avoiding the formation of a tip at the outer end of the blade 102, reducing the leakage vortex at the outer end of the blade 102, thereby reducing the noise of the fan blade, and on the other hand, it can also improve the working capacity of the fan blade.

[0050] A non-closed ring shape means that the first segment 11 and the second segment 12 are at least partially not closed and connected, and some positions around the hollow area 10a are discontinuous. For example, the first segment 11 and the second segment 12 are disconnected at one end of the outer end of the blade 102, but the blade 102 as a whole still presents a ring shape with a hollow area 10a.

[0051] There are many specific structural methods for the hollow region 10a. For example, referring to FIG1 , in one embodiment, the inner end of the first segment 11 and the inner end of the second segment 12 are respectively connected to the hub 101. That is, the blade 102 is now divided into two spaced-apart lobes on the hub 101, so that the first segment 11, the second segment 12, and the hub 101 together form an annular structure. In this way, the effective length of the first segment 11 and the second segment 12 can be increased, thereby improving the overall working capacity of the blade 102. It should be noted that the inner end of the blade 102 refers to the end thereof close to the hub 101, and the outer end refers to the end thereof away from the hub 101. That is, the inner end of the blade 102 corresponds to the root portion thereof, and the outer end of the blade 102 corresponds to the tip portion thereof.

[0052] Of course, in other embodiments, the hollow region 10a can also be directly formed on the blade 102 body and positioned near the outer end of the blade 102. For example, referring to Figure 7, in another embodiment, the inner end of the first segment 11 is connected to the side edge of the second segment 12, and the inner end of the second segment 12 is connected to the hub 101; that is, the inner end of the second segment 12 serves as the root of the blade 102 and is directly connected to the hub 101, while the first segment 11 has no direct connection to the hub 101. In other words, the end of the blade 102 away from the hub 101 bends in a direction opposite to the direction of rotation of the fan blade to form the hollow region 10a. This makes the root of the blade 102 more compact, which helps reduce the weight of the blade 102.

[0053] Referring to Figure 8 , in yet another embodiment, the inner end of the first segment 11 and the inner end of the second segment 12 are connected, and are also connected to the hub 101. In other words, the root portion of the blade 102 is formed by both the first segment 11 and the second segment 12, with the hollow region 10a formed directly on the blade 102. This improves the structural strength of the root portion of the blade 102.

[0054] Specifically, the fan blade of the present application includes a hub 101 and a plurality of blades 102 arranged on the circumferential side of the hub 101, wherein the number of blades 102 can be set according to actual needs, and is generally set to at least two, for example, it can be two, three, five or more. Of course, under the premise of satisfying dynamic balance, it is not ruled out that only a single blade 102 is set. For example, a balancing structure can be set on the hub 101 to keep the entire fan blade stable during operation. For the sake of ease of description, the following mainly describes the structure of a single blade 102, and the structures of other blades 102 are the same or similar to the structure of the blade 102.

[0055] Referring to Figures 1, 7, and 8, in some embodiments, blade 102 further includes a bridging segment 13, which connects the outer end of first segment 11 to the outer end of second segment 12. The bridging segment 13 creates a smooth transition between the first segment 11, the bridging segment 13, and the second segment 12, and together they define a hollow region 10a. The provision of the bridging segment 13 not only optimizes the flow field within hollow region 10a, particularly at the blade tip, but also helps maintain the shape of hollow region 10a. Furthermore, this facilitates the manufacturing and shaping of blade 102 and enhances its aesthetics. Of course, in other embodiments, the distal ends of the first segment 11 and the second segment 12 may be directly connected.

[0056] In one embodiment, the first segment 11, the second segment 12, and the bridge segment 13 are integrally formed, which increases the overall structural strength and stability of the blade 102 while simplifying the manufacturing process. The hollow region 10a also reduces the weight of the blade 102, thereby reducing the overall weight of the fan blade, thereby requiring less driving force to drive the blade to rotate. Alternatively, in some embodiments, a filter can be placed within the hollow region 10a to further filter and purify the air.

[0057] In addition, there are many ways to connect the blades 102 and the hub 101. For example, the blades 102 and the hub 101 can be an integrally formed structure, or they can be separately set and assembled together through assembly structures such as screws and snaps. This application does not make specific restrictions here.

[0058] In some embodiments, the ratio of the chord length of the blade profile of the first segment 11 to the chord length of the blade profile of the second segment 12 ranges from 0.8 to 1.2. That is, the chord lengths of the blade profiles of the first segment 11 and the second segment 12 tend to be consistent. This allows the structures of the first segment 11 and the second segment 12 to be more similar, improving the aesthetics and coordination of the blade 102. In one embodiment, the chord lengths of the blade profiles of the first segment 11 and the second segment 12 are substantially consistent, that is, the ratio of the chord lengths of the blade profiles of the first segment 11 and the second segment 12 is 1.

[0059] In some embodiments, the ratio of the curvature of the blade profile of the first segment 11 to the curvature of the blade profile of the second segment 12 ranges from 0.8 to 1.2. That is, the curvatures of the blade profiles of the first segment 11 and the second segment 12 tend to be consistent. This allows the structures of the first segment 11 and the second segment 12 to be more similar, improving the aesthetics and coordination of the blade 102. In one embodiment, the curvatures of the blade profiles of the first segment 11 and the second segment 12 are substantially consistent, that is, the ratio of the curvatures of the blade profiles of the first segment 11 and the second segment 12 is 1.

[0060] It is worth mentioning that in some embodiments, the ratio of the chord length of the blade profile of the first segment 11 to the chord length of the blade profile of the second segment 12 is in the range of 0.8 to 1.2, and the ratio of the curvature of the blade profile of the first segment 11 to the curvature of the blade profile of the second segment 12 is in the range of 0.8 to 1.2. In other words, the blade curvature and chord length of the first segment 11 and the second segment 12 are consistent. This can make the work capacity of the first segment 11 and the second segment 12 consistent, and make the loads on the first segment 11 and the second segment 12 consistent, which is conducive to maintaining the structural form of the blade 102 and the hollow area 10a during the operation of the fan blade.

[0061] It should be noted that the definition of the relationship between the blade curvature or chord length of the first segment 11 and the second segment 12 applies to the relationship between the same group of blade profiles of the first segment 11 and the second segment 12 located on the same reference cylindrical surface 103. Specifically, referring to FIG3 , the blade profiles of the first segment 11 and the second segment 12 cut by the reference cylindrical surface 103 of the same radius are defined as belonging to the same group. FIG3 shows six groups of blade profiles cut by reference cylindrical surfaces 103 of six different radii, including blade profiles 11a and 12a, blade profiles 11b and 12b, blade profiles 11c and 12c, blade profiles 11d and 12d, blade profiles 11e and 12e, and blade profiles 11f and 12f. Blade profiles 11a and 12a, belonging to the same group, are located at the root of blade 102, while the other five groups of blade profiles are sequentially spaced apart and distributed toward the blade tip. It can be understood that the above-mentioned limitation on the relationship between the blade curvature or chord length of the first segment 11 and the second segment 12 is applicable to the blade profile of the first segment 11 and the blade profile of the second segment 12 belonging to the same group; of course, the blade profile of the first segment 11 and the blade profile of the second segment 12 belonging to different groups can be limited to have the curvature tend to be consistent and / or the chord length tend to be consistent, or no specific limitation can be made. For example, in other embodiments, the chord length of the first segment 11 may gradually increase and then gradually decrease in the direction from the root of the blade 102 toward the tip of the blade, and the chord length of the second segment 12 may also gradually increase and then gradually decrease accordingly.

[0062] In some embodiments, a reference projection plane is defined that passes through both the axis of the hub 101 and the midpoint of the hollow region 10a. The ratio of the overlapping lengths of the projections of the blade profiles of the first segment 11 and the second segment 12 on the reference projection plane to the projected length of the blade profile of the first segment 11 is less than or equal to 40%. In other words, the projection overlap ratio is less than or equal to 40%, such as 30% or 20%. In one embodiment, this ratio is less than or equal to 10%. This allows the blade 102 to be more compact in the axial direction of the hub 101 while ensuring that both the first segment 11 and the second segment 12 can perform well.

[0063] It should be noted that the blade profiles of the first segment 11 and the second segment 12 are projected onto the reference projection plane after being unfolded into a planar state. The projected length and overlap length both refer to the length dimensions along the axis of the hub 101. That is, the blade profiles of the first segment 11 and the second segment 12 are spaced apart axially in the hub 101, or partially overlap on the reference projection plane. Of course, in other embodiments, the blade profiles of the first segment 11 and the second segment 12 may overlap on the reference projection plane by more than 40%, such as 60%, 80%, or 100%.

[0064] In some embodiments, the relative pitch between the airfoil of the first segment 11 and the airfoil of the second segment 12 in the circumferential direction of the hub 101 ranges from 0.7 to 1. It should be noted that the pitch refers to the distance from the leading edge 10b of the first segment 11 to the leading edge 10b of the second segment 12 in the circumferential direction of the hub 101, and the relative pitch is the ratio of the pitch to the chord length of the first segment 11. In other words, the relative pitch can be used to represent the circumferential spacing between the first segment 11 and the second segment 12 in the hub 101. In one embodiment, the relative pitch between the airfoil of the first segment 11 and the airfoil of the second segment 12 ranges from 0.8 to 0.95. It is understandable that if the circumferential spacing between the first segment 11 and the second segment 12 in the hub 101 is too small, airflow disturbances between the first segment 11 and the second segment 12 will occur, increasing friction on the surface of the blade 102 and reducing blade efficiency. If the circumferential spacing between the first segment 11 and the second segment 12 in the hub 101 is too large, pressure loss will increase, leading to insufficient wind pressure. Of course, in other embodiments, the relative pitch of the blade profile of the first segment 11 and the second segment 12 may also range from less than 0.7 to greater than 1.

[0065] Referring to Figures 3 and 4, in some embodiments, in the air intake direction of the fan blade, the blade profile of the first segment 11 is located upstream of the second segment 12; in the rotation direction of the fan blade, the blade profile of the second segment 12 is located upstream of the blade profile of the first segment 11, and the suction surface 10g of the blade profile of the first segment 11 is arranged adjacent to the pressure surface 10f of the blade profile of the second segment 12. In this way, within the flow field of the blade 102, the second segment 12 is located downstream of the first segment 11 and is relatively close to it, allowing the second segment 12 to recover the flow field energy of the first segment 11, thereby further improving the total work capacity of the blade 102. Of course, in other embodiments, the suction surface 10g of the blade profile of the first segment 11 can also be arranged away from the pressure surface 10f of the blade profile of the second segment 12.

[0066] It should be noted that the pressure side 10f of the blade is the side where the blade and the airflow move relative to each other, that is, the direction of the airflow facing the blade. Correspondingly, the suction side 10g of the blade refers to the other side where the blade and the airflow move relative to each other, that is, the direction of the blade facing away from the airflow.

[0067] In some embodiments, the first segment 11 and the second segment 12 form a tandem blade 102. This improves the flow field within the blade 102 through interaction between the first segment 11 and the second segment 12, thereby forming a high-speed jet on the first segment 11 and the second segment 12 and further enhancing the overall work capacity of the blade 102. Of course, in other embodiments, the first segment 11 and the second segment 12 may not form a tandem blade 102. For example, the first segment 11 and the second segment 12 may be spaced apart in the axial direction of the hub 101 and arranged side by side in the circumferential direction of the hub 101.

[0068] The present application also proposes a fan, which includes the aforementioned fan blades. The specific structure of the fan blades refers to the above-mentioned embodiments. Since the fan adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here.

[0069] The present application also proposes a blowing device, which includes the aforementioned fan blades or fan. The specific structure of the fan blades or fan refers to the above-mentioned embodiments. Since the present blowing device adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0070] The air-blowing device includes, but is not limited to, floor fans, ceiling fans, desktop fans, and other fan products. It can also be other devices with axial-flow fan blades (such as air conditioner outdoor units). By using the aforementioned fan blades or blowers, the performance and air volume of the air-blowing device can be effectively improved, thereby enhancing the user experience.

[0071] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A fan blade, wherein, The fan blade includes: a hub; and blades connected to the hub, the blades including a first segment and a second segment, with a hollow region between the first segment and the second segment; A reference cylindrical surface is configured around the axis of the hub, and the intersection line of the reference cylindrical surface and the space of the blade is defined as the blade profile. The blade profile of the first segment protrudes in a direction away from the rotation direction of the fan blade, and the blade profile of the second segment protrudes in a direction away from the rotation direction of the fan blade.

2. The fan blade according to claim 1, wherein, The value range of the ratio of the chord length of the blade profile of the first segment to the chord length of the blade profile of the second segment is from 0.8 to 1.

2.

3. The fan blade according to claim 1, wherein, The value range of the ratio of the curvature of the blade profile of the first segment to the curvature of the blade profile of the second segment is from 0.8 to 1.

2.

4. The fan blade according to claim 1, wherein, Define a reference projection plane passing through the axis of the hub and the midpoint of the hollow region at the same time. The ratio of the overlapping length of the projections of the blade profile of the first segment and the blade profile of the second segment on the reference projection plane to the projection length of the blade profile of the first segment is less than or equal to 40%.

5. The fan blade according to claim 4, wherein, In the circumferential direction of the hub, the value range of the relative pitch of the blade profile of the first segment and the blade profile of the second segment is from 0.7 to 1.

6. The fan blade according to claim 5, wherein, In the air inlet direction of the fan blade, the first segment is located upstream of the second segment; in the rotation direction of the fan blade, the blade profile of the second segment is located upstream of the blade profile of the first segment, and the suction surface of the blade profile of the first segment is arranged adjacent to the pressure surface of the blade profile of the second segment.

7. The fan blade according to claim 6, wherein, The blade profiles of the first segment and the second segment form a tandem blade configuration.

8. The fan blade according to claim 1, wherein, The inner ends of the first segment and the second segment are respectively connected to the hub, and the hollow region is defined between the first segment, the second segment and the hub; Alternatively, the inner end of the first segment is connected to the side edge of the second segment, and the inner end of the second segment is connected to the hub; Alternatively, the inner ends of the first segment and the second segment are connected to each other and are simultaneously connected to the hub.

9. The fan blade according to any one of claims 1 to 8, wherein, The blade further includes a bridging segment connecting the outer ends of the first segment and the second segment, and a smooth transition is provided between the first segment, the bridging segment and the second segment.

10. A blower, wherein, The fan includes the fan blade according to any one of claims 1 to 9.

11. A blowing device, wherein, The blowing device includes the fan blade according to any one of claims 1 to 9 or the fan according to claim 10.

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