A fan and a hair dryer

Abstract

The present application discloses a fan and a hair dryer, the fan comprising: a wind tube, the interior of which is hollow along its axial direction, and the wind tube has an air inlet and an air outlet; a wind wheel, which is arranged inside the wind tube; and a guide vane assembly, which is arranged inside the wind tube and is arranged adjacent to the wind wheel; wherein, in the air inlet direction from the air inlet to the air outlet, the inner wall of the wind tube comprises an air inlet section, a sleeve section and an air outlet section connected in sequence, and the wind wheel and the guide vane assembly are arranged in the sleeve section; the air inlet section is provided with a contraction area, the contraction area extends to form an air inlet, and the contraction area is used to reduce the pressure of the airflow entering the wind wheel; the air outlet section is provided with an expansion area, the expansion area extends to form an air outlet, and the expansion area is used to expand the pressure of the airflow flowing out of the guide vane assembly. In the above manner, the fan in the present application can achieve the air volume required for use without increasing the rotation speed.

Description

Technical Field

[0001] The present application relates to the technical field of household appliances, and in particular to fans and hair dryers. Background Art

[0002] The hair dryer dries by generating wind with a specific temperature. When the hair dryer is powered on, the motor drives the fan blades to rotate, sucking air from the air inlet, heating it through the electric heating element, and blowing it out from the air outlet after forming hot air. Existing hair dryers are developing in the direction of small diameter and short body, which inevitably requires the diameter of the fan inside the hair dryer to become smaller, so that when the fan air volume needs to be guaranteed, the fan speed must be increased, which in turn leads to increased noise and affects the user experience. Therefore, it is necessary to study a fan and a hair dryer. Summary of the invention

[0003] In view of the deficiencies existing in the above-mentioned technologies, the present application provides a fan and a hair dryer, which can improve the air outlet performance.

[0004] In order to solve the above technical problems, the technical solution adopted in this application is:

[0005] A fan comprises: a duct, which is hollow along its axial direction to form a hollow cavity running through the duct, the duct having an air inlet and an air outlet; a wind wheel arranged inside the duct, and used to blow air to the duct to form a high-speed airflow; and a guide vane assembly arranged inside the duct and adjacent to the wind wheel, the guide vane assembly being used to rectify the airflow entering the duct; wherein, in the air inlet direction from the air inlet to the air outlet, the inner wall of the duct comprises an air inlet section, a socket section and an air outlet section connected in sequence, the wind wheel and the guide vane assembly being arranged on the socket section; the air inlet section is provided with a shrinking area, the shrinking area extends to form the air inlet, and the shrinking area is used to reduce the pressure of the airflow entering the wind wheel; the air outlet section is provided with an expanding area, the expanding area extends to form the air outlet, and the expanding area is used to expand the pressure of the airflow flowing out of the guide vane assembly.

[0006] Preferably, the air inlet section includes: a first straight area, which is substantially parallel to the axial direction of the air duct; and a first inclined area, which is respectively connected to the first straight area and the sleeve section, and is arranged at a first angle to the axial direction of the air duct to form the necking area; wherein the first inclined area is farther away from the air inlet than the first straight area.

[0007] Preferably, the sleeve section includes a second straight area and a third straight area which are substantially parallel to the axial direction of the wind cylinder, and the second straight area is respectively connected to the first inclined area and the third straight area; wherein, the second straight area is farther away from the air outlet section than the third straight area, the caliber of the second straight area is smaller than that of the first straight area, the wind wheel is installed in the second straight area, and the guide vane assembly is installed in the third straight area.

[0008] Preferably, the air outlet section includes: a fourth straight area, which is substantially parallel to the axial direction of the air duct; and a second inclined area, which is respectively connected to the third straight area and the fourth straight area, and is arranged at a second angle to the axial direction of the air duct to form the expansion area; wherein, the second inclined area is farther away from the air outlet than the fourth straight area, and the caliber of the fourth straight area is larger than the caliber of the third straight area.

[0009] Preferably, the necking area is an arc segment or an arc chain formed by smoothly connecting multiple arc segments; or, the necking area is a straight line segment or a broken line formed by multiple straight lines.

[0010] Preferably, the wind wheel is arranged close to the air inlet section, and the wind wheel includes a hub connected to the output shaft of the motor and blades arranged on the outer wall of the hub at equal intervals along the circumference of the hub, and the number of the blades is n1; wherein, the blade is constructed so that the cross-section in the circumferential direction of the hub is an arc-shaped and the chord length B corresponding to the cross-section increases with the increase of the blade diameter D; the following relationship is satisfied among the number of blades n1, the chord length B and the blade diameter D: 0.35<(B*n1 / D)<0.48.

[0011] Preferably, the blade comprises a blade root portion connected to the hub and a blade top portion arranged away from the blade root portion, wherein the gap between the blade top portion and the inner wall of the wind tube gradually decreases along the wind inlet direction.

[0012] Preferably, the hub is connected to the output shaft of the motor through a knurled nut; wherein the outer diameter of the hub gradually increases in the wind inlet direction, and the projection of the outer circumference of the hub in the axial direction is a segment of arc or a smooth arc chain composed of multiple segments of arc.

[0013] Preferably, the guide vane assembly is arranged close to the air outlet section, and the guide vane assembly includes a motor fixing seat supporting the motor and a guide vane arranged on the outer wall of the motor fixing seat, and the guide vane is connected to the inner wall of the wind tube to fix the motor to the wind tube; wherein the wind tube, the motor fixing seat and the hub are coaxially arranged.

[0014] In order to solve the above technical problems, another technical solution adopted by this application is:

[0015] An electric hair dryer comprises the blower as described above.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] The fan and hair dryer provided in the present application are provided with a contraction area at the air inlet of the fan and an expansion area at the air outlet. The contraction area can reduce the pressure of the airflow entering the wind wheel, while the expansion area is used to expand the pressure of the airflow out of the guide vane assembly, so that the air volume of the fan can still meet the use requirements without increasing the rotation speed, and the noise problem is effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional structural schematic diagram of the fan in this application;

[0019] Figure 2 is a schematic diagram of the exploded structure of the fan in this application;

[0020] Figure 3 is a cross-sectional schematic diagram of a blower in one embodiment of the present application;

[0021] Figure 4 It is a schematic diagram of an implementation mode of the first inclined surface area L2 in the present application;

[0022] Figure 5 This is one of the schematic diagrams of another implementation of the first inclined surface area L2 in the present application;

[0023] Figure 6 This is the second schematic diagram of another implementation of the first inclined surface area L2 in the present application;

[0024] Figure 7 is a schematic diagram of another implementation of the first inclined surface area L2 in the present application;

[0025] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of the A area in the middle;

[0026] Fig. 9 is a schematic diagram of the three-dimensional structure of the wind wheel in this application;

[0027] Fig.10 is a schematic diagram of the main viewing direction of the wind wheel in this application;

[0028] Fig.11 yes Fig.10 Schematic diagram of the cross section in the CC direction;

[0029] Fig.12 It is a schematic diagram of the structure of the blade in this application;

[0030] Fig.13It is a schematic diagram of the structure of the guide vane in this application;

[0031] Fig.14 It is a schematic diagram of the blade profile of a conventional guide vane;

[0032] Fig.15 It is a structural schematic diagram of the hair dryer in this application. DETAILED DESCRIPTION

[0033] The present application is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the text of the specification. If there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0034] In the description of this application, it is also necessary to explain that, unless otherwise specified and limited, the terms "disposed" and "connected" should be understood in a broader sense. For example, "connected" 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0035] In addition, if the meaning of "and / or" appears in this application, it includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the protection scope required by this application.

[0036] Existing hair dryers are developing in the direction of small diameter and short body, which will inevitably require the diameter of the entire fan to become smaller. As a result, when the fan air volume needs to be guaranteed, its rotation speed must be increased, which in turn leads to increased noise and affects the user experience.

[0037] In view of this, the present application provides a fan, see Figures 1 to 3 , Figure 1 is a schematic diagram of the structure of the fan in this application, Figure 2 is a schematic diagram of the exploded structure of the fan in this application, Figure 31 is a cross-sectional schematic diagram of an embodiment of the fan of the present application, comprising: a wind tube 100, the interior of which is hollowed along its axial direction to form a hollow cavity running through it, and the wind tube 100 has an air inlet 140 and an air outlet 150; a wind wheel 400, which is arranged inside the wind tube 100 and is used to blow air to the wind tube 100 to form a high-speed airflow; and a guide vane assembly 200, which is arranged inside the wind tube 100 and adjacent to the wind wheel 400, and the guide vane assembly 200 is used to rectify the airflow entering the wind tube 100; wherein, in the air inlet direction from the air inlet 140 to the air outlet 150 The inner wall of the air duct 100 includes an air inlet section 110, a sleeve section 120 and an air outlet section 130 which are connected in sequence, and the wind wheel 400 and the guide vane assembly 200 are arranged in the sleeve section 120; the air inlet section 110 is provided with a shrinking area, which extends to form an air inlet 140, and the shrinking area is used to reduce the pressure of the airflow entering the wind wheel 400; the air outlet section 130 is provided with a flaring area, which extends to form an air outlet 150, and the flaring area is used to expand the pressure of the airflow flowing out of the guide vane assembly 200; the wind wheel 400 is arranged close to the air inlet section 110, and the guide vane assembly 200 is arranged close to the air outlet section 130.

[0038] Through the above method, the necking area in the present application can reduce the pressure of the airflow entering the wind wheel 400, and the expansion area is used to expand the airflow out of the guide vane assembly 200, so that the air volume can still meet the use requirements without increasing the rotation speed of the fan, and the noise problem is effectively solved.

[0039] For further information, please refer to Figure 1 The air inlet section 110 includes: a first straight area L1 and a first inclined area L2, the first inclined area L2 is farther away from the air inlet 140 than the first straight area L1; the first straight area L1 is substantially parallel to the axial direction of the wind tube 100, the two ends of the first inclined area L2 are respectively connected to the first straight area L1 and the sleeve section 120, and the first inclined area L2 is set at a first angle α1 with the axial direction of the wind tube 100 to form a constriction area, so that when the fan is working, the airflow is first rectified by the first straight area L1, and then accelerated by the first inclined area L2, so that the airflow pressure at the air inlet 140 of the wind tube along the air inlet direction is gradually reduced, and the airflow can enter the wind wheel 400 at a lower pressure. By designing the air inlet 140 as above, the airflow pressure at the air inlet 140 can be reduced, thereby preventing the airflow in the wind tube 100 from flowing back.

[0040] Specifically, the necking area corresponds to the first slope area L2. There are many ways to implement the necking area. Figures 4 to 6 , which can be an arc or a chain of arcs formed by smoothly connecting multiple arcs. Figure 7 and Figure 8 , or a straight line or a polyline consisting of multiple straight lines; Figure 4is a schematic diagram when the first inclined surface area L2 is a single arc R; Figure 5 and Figure 6 Schematic diagram showing that the first slope area L2 is formed by two circular arcs with radii R1 and R2 connected smoothly. Of course, the first slope area L2 can also be formed by multiple circular arcs with different radii connected smoothly. Figure 3 It is a schematic diagram that the first inclined surface area L2 is composed of a straight line, and there is a first angle α1 between the straight line and the axial direction of the wind tube 100, and the value range of the first angle α1 is: 30°≤α1≤60°; Figure 7 and Figure 8 The first slope area L2 is a broken line composed of three straight line segments, which includes a first straight line segment B1 at an angle β1 to the axial direction of the wind tube 100, a second straight line segment B2 at an angle β2 to the axial direction of the wind tube 100, and a third straight line segment B3 at an angle β3 to the axial direction of the wind tube 100 in the air inlet direction from the air inlet 140 to the air outlet 150. Of course, the first slope area L2 can also be a broken line composed of several straight line segments. The present application is not limited to this, and can also be a combination of arcs and straight lines, which is not further limited here.

[0041] Furthermore, the sleeve section 120 includes a second straight area L3 and a third straight area L4 which are substantially parallel to the axial direction of the wind tube 100, and the second straight area L3 is respectively connected to the first inclined area L2 and the third straight area L4; wherein, the second straight area L3 is farther away from the air outlet section 130 than the third straight area L4, and the caliber of the second straight area L3 is smaller than the caliber of the first straight area L1, and the second straight area L3 is installed with a wind wheel 400, and the three straight areas L4 are installed with a guide vane assembly 200.

[0042] For further information, see Figure 3 The air outlet section 130 includes: a second inclined surface area L5 and a fourth straight area L6. The fourth straight area L6 is substantially parallel to the axial direction of the air duct 100. The second inclined surface area L5 is respectively connected to the third straight area L4 and the fourth straight area L6, and is set at a second angle α2 with the axial direction of the air duct 100 to form a flared area. Among them, the second inclined surface area L5 is farther away from the air outlet 150 than the fourth straight area L6, and the caliber of the fourth straight area L6 is larger than the caliber of the third straight area L4. As a result, the airflow can be expanded in the air outlet section 130, converting kinetic energy into static pressure, improving the pressure resistance of the fan, and reducing exhaust loss.

[0043] For further information, see Figure 3 Combined with Fig. 9The wind wheel 400 is fastened to the output shaft of the motor 300, and is completely nested in the wind tube 100, and can rotate around the output shaft of the motor 300 in the wind tube 100. The wind wheel 400 includes a hub 410 connected to the output shaft of the motor 300 and blades 420 arranged on the outer wall of the hub 410 at equal intervals along the circumference of the hub 410, wherein the hub 410 is installed in the second straight area L3, and the blades 420 are located in the first inclined area L2 and the second straight area L3. The blade 420 has a blade root 421 connected to the hub 410, a blade top 422 arranged away from the blade root, a blade leading edge 423 as the upwind side, and a blade trailing edge 424 as the downwind side, and the blade leading edge 423 and the blade trailing edge 424 are respectively located on both sides of the blade root 421 and the blade top 422. In the second straight region L3, the gap between the blade top 422 and the inner wall of the wind tube 100 gradually decreases along the air inlet direction, thereby effectively preventing the top gap of the blade 420 from flowing back, thereby improving the efficiency of the fan.

[0044] Specifically, see Fig.12 The blade 420 is configured such that the cross section M in the circumferential direction of the hub 410 is arc-shaped and the chord length B corresponding to the cross section M increases with the increase of the radius of the blade 420, that is, the cross-sectional shape of the blade 420 in the circumferential direction of the hub 410 changes continuously according to the radius of the blade 420. The plurality of blades 420 are arranged on the outer wall of the hub 410 in a twisted posture, and the adjacent leading edges and trailing edges of two adjacent blades 420 overlap.

[0045] Specifically, see Figures 9 to 12 , the blade height of blade 420 is defined as the distance from the top 422 to the root 421 of blade 420. If the diameter at a certain blade height G of blade 420 is D, the number n1 of blades 420, the chord length B at the blade height and the diameter D of blade 420 satisfy the following relationship: 0.35<(B*n1 / D)<0.48, and the number n1 of blades 420 satisfies 5≤n1≤13. Based on this, after blade 420 meets the above design, the chord length B gradually increases from the root 421 to the top 422 of blade, and the work capacity of wind wheel 400 is enhanced at the same speed; and the installation angle distortion of blade 420 from the root 421 to the top 422 of blade 420 is small, and the strength of blade 420 is relatively high.

[0046] See also Figure 3 Combined with Fig. 9Considering the existence of assembly error, after the wind wheel 400, the guide vane assembly 200 and the motor 300 are all installed in the wind tube 100, the axial distance between the interface ff between the first straight area L1 and the first inclined area L2 and the leading edge point Q of the blade 420 is less than 0.05*K; wherein the interface ff is perpendicular to the axis of the wind tube 100, the leading edge point Q of the blade 420 is the intersection of the top 422 of the blade and the leading edge 423 of the blade, and K is the length of the first inclined area L2 in the axial direction of the wind tube 100. The best assembly state of the wind wheel 400 is that the leading edge point Q of the blade 420 is located on the interface ff, that is, the axial distance between the interface ff and the leading edge point Q of the blade 420 is zero.

[0047] For further information, see Figure 3 Combined with Fig.11 , the outer diameter of the hub 410 gradually increases in the air inlet direction, wherein the diameter d1 of the small end face of the hub 410 close to the air inlet 140 is smaller than the diameter d2 of the large end face of the hub 410 away from the air inlet 150. Specifically, the projection of the outer peripheral surface of the hub 410 in the axial direction is a segment of arc or a smooth arc chain composed of multiple segments of arc, that is, the outer peripheral surface of the hub 410 is composed of one or more arcs in the axial direction; when the projection of the outer peripheral surface of the hub 410 in the axial direction is a smooth arc chain composed of multiple segments of arc, the number of arc segments n2 ≥ 2, and the radius of each arc is different. Therefore, when the airflow enters the wind tube 100 through the blades 420, the airflow can move along the outer wall of the hub 410 to the guide vane assembly 200, thereby avoiding the phenomenon of intake air backflow and airflow separation at the blade root 421.

[0048] For further information, please refer to Figure 3 Combined with Fig.11 , the hub 410 of the wind wheel 400 can be connected to the output shaft of the motor 300 through the knurled nut 500. Specifically, the knurled nut 500 and the output shaft of the motor 300 are connected by interference fit, and the hub 410 is provided with a mounting hole 411 that matches the knurled nut 500, and the knurled nut 500 is pressed into the mounting hole 411. In order to facilitate the press-fitting of the knurled nut 500 into the mounting hole 411, a groove 412 is provided on the front end face of the hub 410, and the groove 412 is connected to the mounting hole 411. The groove depth of the groove 412 is c, and the value range of the groove depth c is: (d1 / 3) ≤ c ≤ (d1 / 2). The outer circumference of the knurled nut 500 is provided with knurls, so as to increase the bonding strength with the hub 410, reduce the jitter between the wind wheel 400 and the output shaft of the motor 300 when rotating, and reduce noise.

[0049] For further information, see Figure 2 Combined with Figure 3The guide vane assembly 200 includes a motor fixing seat 210 supporting the motor 300 and a guide vane 220 arranged on the outer wall of the motor fixing seat 210. The guide vane 220 connects the motor fixing seat 210 and the inner wall of the wind tube 100 in the third straight area L4 to fix the motor 300 to the wind tube 100; the number of the guide vanes 220 is n3, which satisfies 5≤n3≤13. The guide vanes 220 not only fix the motor 300 in the wind tube 100, but also guide the airflow in the wind wheel 400, thereby homogenizing the airflow. The motor fixing seat 210 has a receiving groove 211 for installing the motor 300 and a through hole 212 formed on the groove wall of the receiving groove 211, through which the output shaft of the motor 300 is passed to the side of the wind wheel 400. After the output shaft of the motor 300 passes through the through hole 212, it is connected to the wind wheel 400, so that the motor 300 drives the wind wheel 400 to rotate when the motor 300 rotates. The wind tube 100, the motor fixing seat 210 and the wheel hub 410 are coaxially arranged.

[0050] Further, in order to reduce the dynamic and static interference effect between the wind wheel 400 and the guide vane 220, the blade shape of the guide vane 220 is designed. Fig.13 , Fig.13 It is a schematic diagram of the blade profile of the guide vane 220. The blade profile of the guide vane 220 includes a pressure surface profile 221, a trailing edge profile 224 as the leeward side, a suction surface profile 222 and a leading edge profile 223 as the upwind side, which are connected in sequence from beginning to end. Among them, the leading edge profile 223 is a single arc line, which is smoothly connected to the starting point of the pressure surface profile 221 and the starting point of the suction surface profile 222; the trailing edge profile 224 connects the tail end of the pressure surface profile 221 and the tail end of the suction surface profile 222; the suction surface profile 222 adopts a single arc design; the pressure surface profile 221 adopts a two-segment arc design, and the leading edge of the guide vane 220 to the 1 / 4-1 / 3 section in the direction of the blade chord length I adopts the profile arc H1, and the profile arc H1 is smoothly connected to its rear segment profile arc H2. Please continue to refer to Fig.14 , Fig.14 This is a schematic diagram of the blade profile of a conventional guide vane. Compared with the conventional guide vane, the pressure surface profile 221 in the present application adopts a two-segment arc design, which can form a recessed portion at the front edge of the pressure surface close to the leading edge profile 223, thereby effectively reducing the dynamic and static interference effect between the wind wheel 400 and the guide vane 220.

[0051] Specifically, after the wind wheel 400, the guide vane assembly 200 and the motor 300 are installed in the wind tube 100, taking into account the existence of assembly errors, the distance between the blade trailing edge 424 of the wind wheel 400 and the leading edge of the guide vane in the axial direction of the wind tube 100 is defined as distance a, and the length of the wind wheel 400 in the axial direction of the wind tube 100 is defined as distance b. The distance a and the distance b satisfy the relationship 0.15b≤a≤0.45b, wherein the leading edge of the guide vane refers to the position of the leading edge profile line 223.

[0052] Furthermore, considering the stability of the fan during operation, a reinforcing rib 160 is provided on the outer wall of the fan tube 100, see Figure 1 The reinforcing ribs 160 include transverse ribs 162 parallel to the airflow direction of the wind tube 100 and annular ribs 161 perpendicular to the airflow direction of the wind tube 100. In this way, the connection stability and reliability between the wind tube 100 and the outer tube 600 can be improved, thereby improving the stability of the fan during operation.

[0053] It can be understood that the fan in the present application can be applied to different usage scenarios, which are explained with examples below.

[0054] The fan in this application can be used for hair dryers, see Fig.15 The hair dryer comprises an outer cylinder 600, the blower arranged inside the outer cylinder 600, and a handle 900 arranged outside the outer cylinder 600. The outer cylinder 600 is hollow inside and has openings at both ends, wherein the blower is located in the hollow cavity of the outer cylinder 600, and an air inlet cover 700 and an air outlet cover 800 are respectively arranged at the openings at both ends of the outer cylinder 600, and the air inlet cover 700 is arranged close to the blower. The handle 900 is connected to the outer cylinder 600 and is located below the outer cylinder 600 to support the outer cylinder 600.

[0055] It can be understood that the above specific applications are merely examples of the fans in this application, and those skilled in the art can make adaptive adjustments according to actual conditions, which will not be elaborated here.

[0056] To summarize, in the present application, the air inlet section 110 is divided into a first straight area L1 and a first inclined area L2. When the airflow enters the fan from the outside, it is rectified through the first straight area L1, and is accelerated and depressurized in the first inclined area L2, so that the airflow pressure along the air inlet direction gradually decreases, and the airflow enters the wind wheel 400 at a lower pressure. Here, it can effectively prevent the pressure P2 at the inlet of the wind wheel 400 from being greater than the pressure P1 at the air inlet 140 due to the airflow being forced to do work and pressurize after entering the wind wheel 400, thereby avoiding the backflow of the airflow and causing the loss of air volume and efficiency. In the present application, the air outlet section 130 is divided into a second inclined area L5 and a fourth straight area L6. Therefore, the airflow can be expanded in the air outlet section 130 to convert kinetic energy into static pressure, thereby improving the pressure resistance of the fan and reducing exhaust losses.

[0057] Although the implementation scheme of the present application has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes, and it can be fully applicable to various fields suitable for the present application. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present application is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A fan, characterized in that: include: The air duct is hollowed out along its axial direction to form a hollow cavity running through it, and the air duct has an air inlet and an air outlet; A wind wheel is arranged inside the wind tube and is used to blow air to the wind tube to form a high-speed airflow; as well as A guide vane assembly is arranged inside the wind tube and adjacent to the wind wheel, and the guide vane assembly is used to rectify the airflow entering the wind tube; Wherein, in the air inlet direction from the air inlet to the air outlet, the inner wall of the wind tube includes an air inlet section, a sleeve section and an air outlet section which are connected in sequence, and the wind wheel and the guide vane assembly are arranged in the sleeve section; The air inlet section is provided with a contraction area, the contraction area extends to form the air inlet, and the contraction area is used to reduce the pressure of the airflow entering the wind wheel; the air outlet section is provided with an expansion area, the expansion area extends to form the air outlet, and the expansion area is used to expand the pressure of the airflow flowing out of the guide vane assembly; The necking area is an arc or an arc chain formed by smoothly connecting multiple arcs; or The necking area is a straight line or a broken line consisting of multiple straight lines; The wind wheel is arranged close to the air inlet section, and comprises a hub connected to the output shaft of the motor, the outer diameter of the hub gradually increases in the air inlet direction, and the projection of the outer peripheral surface of the hub in the axial direction is a segment of arc or a smooth arc chain composed of multiple segments of arc; The wind wheel further comprises blades arranged on the outer wall of the hub at equal intervals along the circumference of the hub, and the number of the blades is n1; Wherein, the blade is configured such that the cross section in the circumferential direction of the hub is in the shape of an arc, and the chord length B corresponding to the cross section increases as the blade diameter D increases; The number of blades n1, the chord length B and the blade diameter D satisfy the following relationship: 0.35<(B×n1 / D)<0.

48.

2. The fan according to claim 1, characterized in that: The air inlet section comprises: A first straight region is substantially parallel to the axial direction of the wind tube; and A first inclined surface area is connected to the first straight area and the sleeve section respectively, and is arranged at a first angle with the axial direction of the wind tube to form the necking area; Wherein, the first inclined area is farther away from the air inlet than the first straight area.

3. The fan according to claim 2, characterized in that: The sleeve section comprises a second straight area and a third straight area substantially parallel to the axial direction of the wind tube, and the second straight area is connected to the first inclined area and the third straight area respectively; The second straight area is farther away from the air outlet section than the third straight area, the diameter of the second straight area is smaller than that of the first straight area, the wind wheel is installed in the second straight area, and the guide vane assembly is installed in the third straight area.

4. The fan according to claim 3, characterized in that: The air outlet section comprises: A fourth straight region is substantially parallel to the axial direction of the wind tube; and The second inclined surface area is connected to the third straight area and the fourth straight area respectively, and is arranged at a second angle with the axial direction of the wind tube to form the expansion area; The second inclined area is farther away from the air outlet than the fourth straight area, and the diameter of the fourth straight area is larger than the diameter of the third straight area.

5. The fan according to claim 1, characterized in that: The blade comprises a blade root portion connected to the hub and a blade top portion arranged away from the blade root portion, wherein a gap between the blade top portion and the inner wall of the wind tube gradually decreases along the wind inlet direction.

6. The fan according to claim 1, characterized in that: The wheel hub is connected to the output shaft of the motor through a knurled nut.

7. The fan according to claim 1, characterized in that: The guide vane assembly is arranged near the air outlet section, and the guide vane assembly includes a motor fixing seat supporting the motor and a guide vane arranged on the outer wall of the motor fixing seat, and the guide vane is connected to the inner wall of the wind tube to fix the motor to the wind tube; Wherein, the wind tube, the motor fixing seat and the wheel hub are coaxially arranged.

8. A hair dryer, characterized in that: Comprising a fan as described in any one of claims 1-7.

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