Fan blade, fan and blowing equipment

Abstract

The invention discloses a fan blade, a fan and blowing equipment, the fan blade comprises a hub and a blade, the blade is connected with the hub, the blade comprises a first segment and a second segment, and a hollow area is arranged between the first segment and the second segment; a reference cylindrical surface is formed around the axis of the hub, space intersection lines of the reference cylindrical surface and the blades are defined as blade profiles, the blade profile of the first segment is arranged in a protruding mode in the direction away from the rotating direction of the fan blades, and the blade profile of the second segment is arranged in a protruding mode in the direction away from the rotating direction of the fan blades. According to the technical scheme, the power capability of the fan blades under the same rotating speed condition can be improved, and then the air supply amount is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of fan blades, and particularly to a fan blade, a fan and a blowing device. Background Art

[0002] Blowing devices are widely used in people's daily lives. Among them, blowing devices using axial flow fan blades (such as floor fans) are favored by many users due to their large wind force and wide blowing range. However, currently, the fan blades are usually of simple straight plate or arc plate structures, resulting in insufficient air delivery at low rotational speeds and difficulty in meeting the usage requirements of users. Summary of the Invention

[0003] The main object of the present invention is to provide a fan blade, aiming to improve the work capacity of the fan blade under the condition of the same rotational speed, and further improve its air delivery.

[0004] To achieve the above object, the fan blade proposed by the present invention includes:

[0005] A hub; and

[0006] Blades connected to the hub, the blades including a first segment and a second segment, and there is a hollow region between the first segment and the second segment;

[0007] A reference cylindrical surface is configured around the axis of the hub, and the spatial intersection line of the reference cylindrical surface and the blade is defined as the blade profile. The blade profile of the first segment protrudes away from the rotation direction of the fan blade, and the blade profile of the second segment protrudes away from the rotation direction of the fan blade.

[0008] Optionally, 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 0.8 to 1.2.

[0009] Optionally, 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 0.8 to 1.2.

[0010] Optionally, a reference projection plane is defined to pass through the axis of the hub and the midpoint of the hollow region at the same time. 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, and the ratio of the projection length of the blade profile of the first segment is less than or equal to 40%.

[0011] Optionally, 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 0.7 to 1.

[0012] Optionally, 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 airfoil of the second segment is located upstream of the airfoil of the first segment, and the suction surface of the airfoil of the first segment is arranged adjacent to the pressure surface of the airfoil of the second segment.

[0013] Optionally, the airfoils of the first segment and the second segment form a tandem blade configuration.

[0014] Optionally, the inner ends of the first segment and the second segment are respectively connected to the hub, and the hollow region is defined among the first segment, the second segment and the hub.

[0015] Optionally, 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.

[0016] Optionally, the inner ends of the first segment and the second segment are connected to each other and are simultaneously connected to the hub.

[0017] Optionally, the blade further includes a bridging segment that connects the outer ends of the first segment and the second segment, and a smooth transition is formed among the first segment, the bridging segment and the second segment.

[0018] The present invention also provides a fan, including the aforementioned fan blade.

[0019] The present invention also provides a blowing device, including the aforementioned fan blade or fan.

[0020] In the technical solution of the present invention, since the convex directions of the airfoils of the first segment and the second segment are the same, that is, the airfoils of the first segment and the second segment both protrude away from the rotation direction of the fan blade, the work done by the first segment and the second segment can be superimposed, thereby improving the total work capacity of the blade and the work capacity of the fan blade under the same rotational speed condition, and further improving the air delivery volume of the fan blade. On the other hand, the fan applying the fan blade of the present application can operate at a lower rotational speed and power to meet the same air delivery volume requirement, which is beneficial to reducing the energy consumption of the fan. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0022] Figure 1 It is a schematic structural diagram of an embodiment of the fan blade of the present invention;

[0023] Figure 2 is Figure 1 A schematic diagram of a set of blade profiles formed by the intersection of a blade of the middle fan blade with a reference cylindrical surface;

[0024] Figure 3 is Figure 2 A schematic diagram of multiple sets of blade profiles formed by the intersection of the blades of the middle fan blade with multiple different reference cylindrical surfaces;

[0025] Figure 4 is Figure 3 A schematic diagram of the structure of the same set of blade profiles after being unfolded into a planar state;

[0026] Figure 5 is Figure 4 A schematic diagram of the elemental - level velocity triangle analysis of two blade profiles;

[0027] Figure 6 is Figure 1 The power - air volume relationship diagram of the shown fan blade and the fan blade of the prior art;

[0028] Figure 7 A schematic diagram of the structure of another embodiment of the fan blade of the present invention;

[0029] Figure 8 A schematic diagram of the structure of yet another embodiment of the fan blade of the present invention.

[0030] Explanation of the reference numerals in the drawings:

[0031] Reference numeral Name Reference numeral Name 101 Hub 10e Chord line 102 Vane 10f Pressure surface 103 Reference cylindrical surface 10g Suction surface 10a Hollow region 11 First segment 10b Leading edge 12 Second segment 10c Trailing edge 13 Bridging segment 10d Central axis

[0032] The realization, functional characteristics and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0034] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0035] In the present invention, unless otherwise clearly specified or limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" can explicitly or implicitly include at least one such feature. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or the solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0037] The present invention provides a fan blade. Please refer to Figures 1 to 8 , in some embodiments of the present invention, the fan blade includes:

[0038] a hub 101; and

[0039] a blade 102, connected to the hub 101. The blade 102 includes a first segment 11 and a second segment 12. At least part of the first segment 11 and the second segment 12 are spaced apart in the circumferential and / or axial directions of the hub 101, and there is a hollow region 10a between the first segment 11 and the second segment 12;

[0040] A reference cylindrical surface 103 is configured around the axis of the hub 101. 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 protrudes in a direction away from the rotation direction of the fan blade, and the blade profile of the second segment 12 protrudes in a direction away from the rotation direction of the fan blade.

[0041] Specifically, please refer to Figure 4 , Figure 4 For Figure 3Schematic diagram of the structure of the same group of blades after being unfolded into a plane state, in this embodiment, optionally, in the rotation direction 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 is located upstream of the first segment 11 or the two are arranged side by side; in the rotation direction of the fan blade, the first segment 11 is located upstream of the second segment 12 or the two are arranged side by side.

[0042] Figure 4 In the figure, the blade profiles of the first segment 11 and the second segment 12 both have a trailing edge 10c and a leading edge 10b relatively arranged along the rotation direction of the blade. In the wind inlet direction of the 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 blade, which means that both blade profiles protrude away from the rotation direction of the blade, that is, the component of the protruding direction of the blade profile in the rotation direction of the blade is set in the opposite direction to the rotation direction of the blade.

[0043] Please also refer to Figure 5 , the blade profiles of the first segment 11 and the second segment 12 are analyzed respectively with the primitive-level velocity triangle, and 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 tangent direction of the 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 is defined as W21, and the relative velocity with its trailing edge 10c is defined as W22, ΔW2u extends along the tangent direction of the blade rotation direction and is used to represent the speed change from W21 to W22.

[0044] Depend on Figure 5 It can be seen that in the technical solution of the present invention, since the blade profiles of the first segment 11 and the second segment 12 are convex in the same direction, that is, the blade profiles of the first segment 11 and the second segment 12 are both convex 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 improving the air supply of the fan blade. On the other hand, the fan using the fan blade of the present application can run at a lower speed and power to meet the same air supply requirement, which is beneficial to reduce the energy consumption of the fan.

[0045] For details, please refer to Figure 6, Figure 6 is Figure 1 the power-air volume relationship diagram of the shown fan blade and the prior art fan blade. Among them, the blade 102 of the prior art fan blade is a simple arc plate structure. It can be seen from Figure 6 that under the condition of the same air volume, the power required by the fan blade of the present application is lower than that of the prior art.

[0046] It is worth mentioning that, optionally in this embodiment, the maximum thickness dimension of the leading edge 10b of the airfoil is greater than the maximum thickness dimension of the trailing edge 10c, that is, the airfoil presents the characteristics of a thick leading edge and a thin trailing edge 10c. In this way, it is beneficial to improve the flow field on the first segment 11 and the second segment 12, and further reduce the aerodynamic noise of the fan blade. It should be noted that the thickness dimension of the airfoil refers to the width dimension of the airfoil in the direction perpendicular to its central axis 10d. Of course, in other embodiments, the maximum thickness dimensions of the leading edge and the trailing edge 10c of the airfoil may also tend to be the same, or the maximum thickness dimension of the leading edge is less than the maximum thickness dimension of the trailing edge 10c.

[0047] It can be understood that at least part of the first segment 11 and the second segment 12 are spaced apart in the circumferential and / or axial directions of the hub 101. This can either mean that at least part of the first segment 11 and the second segment 12 are only spaced apart along the axial direction of the hub 101. At this time, the first segment 11 and the second segment 12 are axially opposite to each other on the hub 101, and the corresponding hollow region 10a has a certain thickness; it can also mean that at least part of the first segment 11 and the second segment 12 are only spaced apart along the circumferential direction of the hub 101. At this time, the first segment 11 and the second segment 12 are circumferentially opposite to each other on the hub 101, and the corresponding hollow region 10a has a certain width; it can also be that at least part of the first segment 11 and the second segment 12 are spaced apart along both the axial and circumferential directions of the hub 101 at the same time. At this time, the first segment 11 and the second segment 12 are misaligned on the hub 101.

[0048] That the first segment 11 and the second segment 12 enclose a hollow region 10a means that the first segment 11 and the second segment 12 jointly enclose a ring structure, and the hollow region 10a is the center of the ring structure. The ring structure enclosed by the first segment 11 and the second segment 12 can be either a closed ring or a non-closed ring. It should be noted that the so-called closed ring means that the first segment 11 and the second segment 12 are closedly connected, and the periphery of the hollow region 10a is continuously connected without a gap. For example, please refer to Figure 1In one embodiment, the blade 102 further includes a bridge segment 13, the bridge segment 13 connects the outer end of the first segment 11 and the outer end of the second segment 12, the first segment 11, the bridge segment 13 and the second segment 12 are smoothly transitioned, and a hollow area 10a is defined between the first segment 11, the second segment 12, the bridge 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 the curved surface transition of the bridge segment 13, so that the first segment 11 and the second segment 12 are connected by the 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.

[0049] 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.

[0050] There are many specific structural methods for the hollow area 10a. For example, please refer to Figure 1 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, at this time, the blade 102 is divided into two spaced-apart blades on the hub 101, so that the first segment 11, the second segment 12 and the hub 101 together enclose a ring structure. In this way, the effective length of the first segment 11 and the second segment 12 can be increased, thereby improving the total working capacity of the blade 102. It should be noted that the inner end of the blade 102 refers to the end close to the hub 101, and the outer end refers to the end away from the hub 101, that is, the inner end of the blade 102 corresponds to the root of the blade, and the outer end of the blade 102 corresponds to the tip of the blade.

[0051] Of course, in other embodiments, the hollow area 10a may also be directly opened on the blade 102 body and disposed close to the outer end of the blade 102. For example, please refer 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 is not directly connected to the hub 101, that is, the end of the blade 102 away from the hub 101 is bent in a direction opposite to the rotation direction of the fan blade to form a hollow area 10a. In this way, the root of the blade 102 can be made smaller, which is conducive to reducing the weight of the blade 102.

[0052] Please refer to Figure 8, in another embodiment, the inner ends of the first segment 11 and the second segment 12 are connected and simultaneously connected to the hub 101. That is to say, the root part of the blade 102 is simultaneously constituted by the first segment 11 and the second segment 12, and the hollow region 10a is directly formed on the blade 102. In this way, the structural strength of the root part of the blade 102 can be improved.

[0053] Specifically, the fan blade of the present application includes a hub 101 and a plurality of blades 102 provided on the circumferential side of the hub 101. The number of the blades 102 can be set according to actual needs, generally set to at least two. For example, it can be two, three, five or more. Of course, on the premise of meeting dynamic balance, the case of only setting a single blade 102 is not excluded. For example, a balance structure can be provided on the hub 101 to keep the whole fan blade stable during operation. For the convenience of description, the structure of a single blade 102 will be mainly described below, and the structures of other blades 102 are the same as or similar to the structure of this blade 102.

[0054] Please refer to Figure 1 , Figure 7 and Figure 8 , in some embodiments, optionally, the blade 102 further includes a bridging segment 13. The bridging segment 13 connects the outer end of the first segment 11 and the outer end of the second segment 12. The first segment 11, the bridging segment 13 and the second segment 12 are smoothly transitioned, and jointly define the hollow region 10a. In this way, by providing the bridging segment 13, not only can the flow field of the blade 102 in the hollow region 10a, especially the tip part, be optimized, but also it is beneficial to maintain the shape of the hollow region 10a. On the other hand, it is also beneficial to the manufacturing and shaping of the blade 102 and improve its aesthetics. Of course, in other embodiments, the distal ends of the first segment 11 and the second segment 12 can also be directly connected.

[0055] Optionally, the first segment 11, the second segment 12 and the bridging segment 13 are integrally formed, so that the overall structural strength of the blade 102 is higher, the stability is better, and at the same time, the manufacturing process can be simplified. The hollow region 10a can also reduce the weight of the blade 102, and further reduce the overall weight of the fan blade. In this way, only a smaller driving force is required to drive the fan blade to rotate. Or, in some embodiments, a filter screen can also be provided in the hollow region 10a, which can also play a role in filtering and purifying.

[0056] In addition, there are various connection methods between the blade 102 and the hub 101. For example, the blade 102 and the hub 101 can be integrally formed structures, or they can be separately provided and assembled together through assembly structures such as screws and buckles. The present application does not make specific limitations here.

[0057] In some embodiments, optionally, the value range of 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 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 the same. In this way, the structures of the first segment 11 and the second segment 12 can be made relatively close, and the aesthetics and coordination of the blade 102 can be improved. Further optionally, the chord lengths of the blade profiles of the first segment 11 and the second segment 12 are basically the same, that is, the ratio of the chord lengths of the blade profiles of the first segment 11 and the second segment 12 is 1.

[0058] In some embodiments, optionally, the value range of 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 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 the same. In this way, the structures of the first segment 11 and the second segment 12 can be made relatively close, and the aesthetics and coordination of the blade 102 can be improved. Further optionally, the curvatures of the blade profiles of the first segment 11 and the second segment 12 are basically the same, that is, the ratio of the curvatures of the blade profiles of the first segment 11 and the second segment 12 is 1.

[0059] It is worth mentioning that in some embodiments, the value range of 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 from 0.8 to 1.2, and the value range of 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 from 0.8 to 1.2. That is, the curvatures and chord lengths of the blade profiles of the first segment 11 and the second segment 12 both tend to be the same. In this way, the work capacities of the first segment 11 and the second segment 12 can be made to tend to be the same, and the loads on the first segment 11 and the second segment 12 can be made to tend to be the same, which is conducive to maintaining the structural forms of the blade 102 and the hollow region 10a during the operation of the fan blade.

[0060] It should be noted that the limitations on the relationship between the curvature or chord length of the blade profiles of the first segment 11 and the second segment 12 are all for the relationship between the same set of blade profiles of the first segment 11 and the second segment 12 located on the same reference cylindrical surface 103. Specifically, please refer to Figure 3 , and define that the blade profiles of the first segment 11 and the second segment 12 intercepted by the reference cylindrical surface 103 with the same radius belong to the same group. Figure 3Six sets of blade profiles respectively intercepted by six reference cylindrical surfaces 103 with different radii are shown in total, including blade profile 11a and blade profile 12a, blade profile 11b and blade profile 12b, blade profile 11c and blade profile 12c, blade profile 11d and blade profile 12d, blade profile 11e and blade profile 12e, blade profile 11f and blade profile 12f. Among them, the blade profile 11a and the blade profile 12a belonging to the same set are located at the blade root part of the blade 102, and the other five sets of blade profiles are sequentially and spacedly distributed along the direction close to the blade tip. It can be understood that the above limitation on the relationship between the blade profile curvature or chord length of the first segment 11 and the second segment 12 preferably applies to the blade profiles of the first segment 11 and the second segment 12 belonging to the same set. Of course, for the blade profiles of the first segment 11 and the second segment 12 belonging to different sets, their curvatures can be limited to be consistent and / or their chord lengths can be limited to be consistent, or no specific limitation can be made. For example, in some other embodiments, in the direction from the blade root to the blade tip of the blade 102, the chord length of the first segment 11 gradually increases and then gradually decreases, and the chord length of the second segment 12 correspondingly gradually increases and then gradually decreases.

[0061] In some embodiments, a reference projection plane is defined to pass through the axis of the hub 101 and the midpoint of the hollow region 10a at the same time. The ratio of the overlapping length of the projections of the blade profiles of the first segment 11 and the second segment 12 on the reference projection plane to the projection length of the blade profile of the first segment 11 is less than or equal to 40%, that is, the projection overlapping ratio is less than or equal to 40%, such as 30% or 20%, etc. Preferably, this ratio is less than or equal to 10%. In this way, the size of the blade 102 in the axial direction of the hub 101 can be made more compact, and at the same time, both the first segment 11 and the second segment 12 can exert good work capacity.

[0062] 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, and both the projection length and the overlapping length refer to the length dimension in the axial direction of the hub 101. That is, the blade profiles of the first segment 11 and the second segment 12 are spaced apart in the axial direction of the hub 101, or partially overlap on the reference projection plane. Of course, in other embodiments, the overlapping ratio of the blade profiles of the first segment 11 and the second segment 12 on the reference projection plane can also exceed 40%, such as 60%, 80% or 100%.

[0063] In some embodiments, optionally, in the circumferential direction of the hub 101, the value range of the relative pitch of the blade profile of the first segment 11 and the blade profile of the second segment 12 is 0.7 to 1. It should be noted that the pitch refers to the distance between the leading edge 10b of the first segment 11 and 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. That is, the relative pitch can be used to represent the spacing between the first segment 11 and the second segment 12 in the circumferential direction of the hub 101. Preferably, the value range of the relative pitch of the blade profile of the first segment 11 and the blade profile of the second segment 12 is 0.8 to 0.95. It can be understood that if the spacing between the first segment 11 and the second segment 12 in the circumferential direction of the hub 101 is too small, it will cause air flow disturbance between the first segment 11 and the second segment 12, increase the frictional force suffered by the air on the surface of the blade 102, thereby reducing the efficiency of the fan blade; if the spacing between the first segment 11 and the second segment 12 in the circumferential direction of the hub 101 is too large, it will cause an increase in pressure loss and insufficient wind pressure. Of course, in other embodiments, the value range of the relative pitch of the blade profile of the first segment 11 and the blade profile of the second segment 12 can also be less than 0.7 or greater than 1.

[0064] Please refer to Figure 3 and Figure 4 , in some embodiments, optionally, in the air inlet direction of the fan blade, the blade profile of the first segment 11 is located upstream of the blade profile 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. Thus, in the flow field of the blade 102, the second segment 12 is located downstream of the first segment 11 and is relatively close, so that the second segment 12 can 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, it can also be that the suction surface 10g of the blade profile of the first segment 11 is arranged away from the pressure surface 10f of the blade profile of the second segment 12.

[0065] It should be noted that the pressure surface 10f of the blade is the side where the blade moves relative to the air flow, that is, the air flow direction faced by the blade. Correspondingly, the suction surface 10g of the blade refers to the other side where the blade moves relative to the air flow, that is, the direction of the blade that the air flow turns away from.

[0066] In some embodiments, optionally, the first segment 11 and the second segment 12 form a tandem blade 102. In this way, the flow field inside can be improved by the interaction between the first segment 11 and the second segment 12, so that a high-speed jet can be formed on the first segment 11 and the second segment 12, and the total work capacity of the blade 102 can be further enhanced. 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 are arranged at intervals in the axial direction of the hub 101 and are arranged side by side in the circumferential direction of the hub 101.

[0067] The present invention also provides a fan, which includes the aforementioned fan blade. The specific structure of the fan blade refers to the above embodiments. Since this fan adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0068] The present invention also provides a blowing device, which includes the aforementioned fan blade or fan. The specific structure of the fan blade or fan refers to the above embodiments. Since this blowing device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0069] Among them, the blowing device includes, but is not limited to, fan products such as floor fans, ceiling fans, and table fans. The blowing device can also be other devices with axial-flow fan blades (such as the outdoor unit of an air conditioner). By adopting the above-mentioned fan blade or fan, the work capacity and air delivery volume of the blowing device can be effectively improved, thereby enhancing the user experience.

[0070] The above are only optional embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A fan blade, characterized in that, Comprising: a hub; and blades, connecting to the hub, the blades comprising 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 spatial intersection line between the reference cylindrical surface and 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 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, characterized in that, 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, characterized in that, The blade profiles of the first segment and the second segment form a tandem blade form.

8. The fan blade according to claim 1, characterized in that, 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, characterized in that, The blade further includes a bridging segment, the bridging segment connecting the outer ends of the first segment and the second segment, and there is a smooth transition between the first segment, the bridging segment and the second segment.

10. A fan, characterized in that, Comprising a fan blade according to any one of claims 1 to 9.

11. A hair dryer device, characterized in that, Comprising a fan blade according to any one of claims 1 to 9 or a fan according to claim 10.

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