Mixed flow impellers, fan components, power systems, fans

Abstract

The present invention provides a mixed flow rotor, a fan assembly, a power system, and a fan. The mixed flow rotor includes a hub and a plurality of blades arranged circumferentially of the hub. The blades have a suction surface and a pressure surface, and an inlet shear angle α, where α has a value of [25°, 40°]; and an outlet shear angle β, where β has a value of [30°, 40°]. Under the constraints of the aforementioned inlet and outlet shear angles, the mixed flow rotor of the present invention has a small turning angle of the airflow within the mixed flow rotor. The small turning angle reduces kinetic energy loss during the turning process, thereby ensuring the outlet pressure and air volume of the mixed flow rotor.

Description

Technical Field

[0001] The present invention relates to the technical field of household appliances, and in particular to a mixed flow fan wheel, a fan assembly, a power system, and a fan. Background Art

[0002] In the traditional bladeless fan structure, the outside air enters the air duct system under the drive of the power device. The power device is equipped with a fan, and the fan is equipped with a wind wheel. The wind wheel converts the outside gas into high-speed and high-pressure gas, which flows into the outlet air duct under the guidance of the guide air duct and is discharged from the air outlet gap.

[0003] However, when the inlet flow rate of a bladeless fan is fixed, the smaller the outlet gap (generally 2-5mm), the greater the air outlet speed and the better the jet effect, which can fully drive the surrounding gas forward. However, a small outlet gap will cause the bladeless fan to have a large air outlet resistance, which requires the above-mentioned fan to provide higher wind pressure and air volume. Summary of the Invention

[0004] Therefore, the present invention aims to further improve the air outlet effect of a bladeless fan, thereby providing a mixed flow wind wheel, a fan assembly, a power system, and a fan.

[0005] In order to solve the above problems, the present invention provides a mixed flow wind wheel, comprising a hub and a plurality of blades arranged in the circumferential direction of the hub, wherein the blades have a suction surface and a pressure surface, and the middle of the suction surface and the pressure surface is defined as the middle surface; a cylindrical surface M formed with the rotating shaft of the hub as the central axis intersects with the middle surface, and the intersection point of the cylindrical surface and the end line N of the blade leading edge of the middle surface is defined as the air inlet intersection point A, and the intersection point of the cylindrical surface M and the end line P of the blade trailing edge of the middle surface is defined as the air outlet intersection point B, and a line is drawn through points A and B. The blade profile curve Q of the blade; the tangent line of the blade profile curve Q passing through point A is the first tangent line, the tangent line of the axial section of the cylindrical surface M passing through point A is the second tangent line, the angle between the first tangent line and the second tangent line is the inlet tangent angle α, and the value of α is [25°, 40°]; the tangent line of the blade profile curve Q passing through point B is the third tangent line, the tangent line of the axial section of the cylindrical surface M passing through point B is the fourth tangent line, the angle between the third tangent line and the fourth tangent line is the outlet tangent angle β, and the value of β is [30°, 40°].

[0006] Furthermore, the air inlet angle α is 32°, and the air outlet angle β is 35°.

[0007] Furthermore, on the middle surface, the curve intersecting with the outer surface of the hub is taken as the lower end line, the outermost curve of the middle surface away from the hub is taken as the upper end line, and any curve between the upper end line and the lower end line is taken as the middle end line. The conformal transformation angle is defined as 10°, the coordinates of the intersection on the two-dimensional projection surface are defined as X and Y, and the ratios of the above coordinate values ​​to the diameter of the mixed flow wind wheel are defined as x and y, respectively, wherein the x corresponding to the lower end line satisfies [0.05, 0.35], and the y satisfies [0.045, 0.30]; the x corresponding to the middle end line satisfies [0.01, 0.35], and the y satisfies [0.15, 0.35]; the x corresponding to the upper end line satisfies [0.005, 0.30], and the y satisfies [0.24, 0.40].

[0008] Furthermore, the blade wrap angle σ is [80°, 100°].

[0009] Furthermore, the blade wrap angle σ is 90°.

[0010] Furthermore, the end surface of the leading edge of the blade includes a straight surface arranged on a side close to the hub, and a curved surface connected to the straight surface.

[0011] Furthermore, a plurality of tooth-shaped grooves are provided on the end surface of the trailing edge of the blade.

[0012] Furthermore, the blades include a main blade and an auxiliary blade sandwiched between the two main blades, and the leading edge of the auxiliary blade is arranged lower than the leading edge of the main blade in the axial height of the hub.

[0013] Furthermore, the plurality of blades are distributed at equal intervals in the circumferential direction at the same height of the hub.

[0014] The present invention further provides a fan assembly comprising any one of the mixed flow wind wheels described above; and a drive motor, wherein the mixed flow wind wheel is arranged on a motor shaft of the drive motor.

[0015] Furthermore, it also includes a shell covering the mixed flow wind wheel, a fluid channel is constructed between the inner side wall of the shell and the outer surface of the hub, and the blades are accommodated in the fluid channel.

[0016] Furthermore, the shell is integrally formed on the mixed flow wind wheel.

[0017] The present invention also provides a power system comprising any of the mixed flow wind wheels described above; or any of the wind turbine components described above.

[0018] The present invention also provides a fan comprising the power system described above.

[0019] Furthermore, the fan is a bladeless fan.

[0020] The technical solution of the present invention has the following advantages:

[0021] 1. The mixed flow wind wheel of the present invention comprises a hub and a plurality of blades arranged in the circumferential direction of the hub, wherein the blades have a suction surface and a pressure surface, and the middle of the suction surface and the pressure surface is defined as the mid-surface; a cylindrical surface M formed with the rotation axis of the hub as the central axis intersects with the mid-surface, and the intersection point of the cylindrical surface and the end line N of the blade leading edge of the mid-surface is defined as the air inlet intersection point A, and the intersection point of the cylindrical surface M and the end line P of the blade trailing edge of the mid-surface is defined as the air outlet intersection point B, and the blade is formed through points A and B. Shape curve Q; the tangent line of the blade curve Q through point A is the first tangent line, the tangent line of the axial section of the cylindrical surface M through point A is the second tangent line, the angle between the first tangent line and the second tangent line is the inlet tangent angle α, and the value of α is [25°, 40°]; the tangent line of the blade curve Q through point B is the third tangent line, the tangent line of the axial section of the cylindrical surface M through point B is the fourth tangent line, the angle between the third tangent line and the fourth tangent line is the outlet tangent angle β, and the value of β is [30°, 40°].

[0022] Under the constraints of the above-mentioned inlet cutting angle and outlet cutting angle, the mixed flow wind wheel in the present invention has a small turning angle of the airflow in the mixed flow wind wheel. The small turning angle can reduce the kinetic energy loss caused by the turning process, thereby ensuring the outlet wind pressure and air volume of the mixed flow wind wheel.

[0023] 2. In the mixed flow wind wheel of the present invention, on the middle surface, the curve intersecting with the outer surface of the hub is taken as the lower end line, the outermost curve of the middle surface away from the hub is taken as the upper end line, and any curve between the upper end line and the lower end line is taken as the middle end line. The conformal transformation angle is defined as 10°, the coordinates of the intersection on the two-dimensional projection surface are defined as X and Y, and the ratios of the above coordinate values ​​to the diameter of the mixed flow wind wheel are defined as x and y, respectively, wherein the x corresponding to the lower end line satisfies [0.05, 0.35], and the y satisfies [0.045, 0.30]; the x corresponding to the middle end line satisfies [0.01, 0.35], and the y satisfies [0.15, 0.35]; the x corresponding to the upper end line satisfies [0.005, 0.30], and the y satisfies [0.24, 0.40]. The blade shape is further constrained. This type of blade shape has better flow-guiding ability, which can reduce the kinetic energy loss along the airflow during the rotation process, thereby increasing the final air output.

[0024] 3. The blade wrap angle σ of the mixed flow impeller in the present invention is [80°, 100°]. The blades within the above angle range have strong working capacity and can increase the wind pressure.

[0025] 4. The trailing edge of the mixed flow impeller of the present invention is provided with a plurality of tooth-shaped grooves. The tooth-shaped grooves form vortices, which can effectively reduce the horseshoe pits formed by the interaction between the pressure surface and the suction surface, and reduce aerodynamic vortex noise.

[0026] 5. In the mixed flow impeller of the present invention, the blades are equally spaced in the circumferential direction at the same height of the hub. This equal spacing ensures uniform flow distribution across each blade. This uniform flow distribution ensures stable and consistent fluid pressure across each blade, thereby effectively extending the life of the guide vanes. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic structural diagram of the pressure surface, suction surface, and mid-surface of the mixed flow wind wheel blades in Example 1 provided by the present invention;

[0029] Figure 2 A schematic structural diagram of the mixed flow wind wheel in Example 1 provided by the present invention;

[0030] Figure 3 A schematic diagram of a segmentation angle in the conformal transformation in Example 1 provided by the present invention;

[0031] Figure 4 A schematic diagram of the molding principle of the mixed flow wind turbine blades in Example 1 provided by the present invention;

[0032] Figure 5 A schematic diagram of the blade wrap angle in Example 1 provided by the present invention;

[0033] Figure 6 A schematic diagram of the air inlet and outlet angles in Example 1 provided by the present invention;

[0034] Figure 7 A schematic structural diagram of a fan assembly in Example 2 provided by the present invention;

[0035] Figure 8 This is a schematic diagram of the structure of the power system in Example 3 provided by the present invention;

[0036] Figure 9 This is a cross-sectional view of the power system in Example 3 provided by the present invention.

[0037] Description of reference numerals:

[0038] 1-wheel hub;

[0039] 2-blade; 21-suction surface; 22-pressure surface; 23-center surface; 24-flat surface; 25-cambered surface; 26-main blade; 27-auxiliary blade; 28-toothed groove;

[0040] 3-Drive motor;

[0041] 4-shell;

[0042] 5-locking piece;

[0043] 6-upper shell;

[0044] 7-motor housing;

[0045] 8 - diffuser;

[0046] 9-Lower housing. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0050] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] Example 1

[0052] like Figures 1 to 6 The figure shows a mixed flow impeller provided by this embodiment, comprising a hub 1 and a plurality of blades 2 arranged circumferentially around the hub 1. The blades 2 have a suction surface 21 and a pressure surface 22. The pressure surface 22 of the blade 2 refers to the surface of the blade that applies pressure to the fluid, i.e., the surface where the blade performs work, and is typically concave. The suction surface 21 of the blade refers to the surface of the blade 2 that is impacted by the fluid due to pressure reduction, and is typically convex.

[0053] The following is a brief explanation of the leading edge and trailing edge of the blade. The leading edge of the blade is the flow surface of the blade 2 that begins to contact the airflow along the direction of the airflow, and the trailing edge of the blade is the end surface of the tail end of the blade 2 along the direction of the airflow.

[0054] In order to more accurately reflect the characteristics of the blade 2, in this embodiment, the equidistant point between the suction surface 21 and the pressure surface 22 is defined as the middle surface 23, that is, the distance from any point on the middle surface 23 to the suction surface 21 and the pressure surface 22 is equal, ensuring that the middle surface 23 is an intermediate curved surface along the thickness direction of the blade 2, which can better express the flow surface characteristics of the blade 2.

[0055] The intersection of the middle surface 23 and the leading edge of the blade generates an end line N at the leading edge of the blade, and the intersection of the middle surface 23 and the trailing edge of the blade generates an end line P of the trailing edge of the blade.

[0056] like Figure 6 As shown, based on the above explanation, a number of cylindrical surfaces M with different radii are formed with the rotation axis L1 of the hub 1 as the central axis, intersecting with the middle surface 23, and the intersection of the cylindrical surface M1 and the end line N of the blade leading edge of the middle surface 23 is defined as the air inlet intersection point A, and the intersection of the cylindrical surface M2 and the end line P of the blade trailing edge of the middle surface 23 is defined as the air outlet intersection point B; the blade profile curve Q of the blade 2 is made through the two points A and B. Here is a brief explanation of the blade profile curve Q. First, it is a curve on the middle surface 23, and any point on it is at an equal distance from the upper end line and the lower end line mentioned below. It is also to reflect the Characteristics of the blade profile: the tangent line of the blade profile curve Q passing through point A is the first tangent line n, the tangent line of the axial section of the cylindrical surface M1 passing through point A is the second tangent line m1, the angle between the first tangent line n and the second tangent line m1 is the inlet tangent angle α, and the value of α is [25°, 40°]; the tangent line of the blade profile curve Q passing through point B is the third tangent line p, the tangent line of the axial section of the cylindrical surface M2 passing through point B is the fourth tangent line m2, the angle between the third tangent line p and the fourth tangent line m2 is the outlet tangent angle β, and the value of β is [30°, 40°]. In this embodiment, the inlet tangent angle α is 32°, and the outlet tangent angle β is 35°.

[0057] The cylindrical surface M1 and cylindrical surface M2 mentioned above merely represent cylindrical surfaces M with different diameters for distinction.

[0058] In this embodiment, under the constraints of the above-mentioned inlet cutting angle α and outlet cutting angle β, the mixed flow wind wheel has a small turning angle of the airflow in the mixed flow wind wheel. The small turning angle can reduce the kinetic energy loss caused by the turning process, thereby ensuring the outlet wind pressure and air volume of the mixed flow wind wheel.

[0059] Based on this, in order to further illustrate the effect, a simulation test was conducted on the air output of the mixed flow impeller in this embodiment, and the following simulation results were obtained, as shown in Table 1 below:

[0060]

[0061] Table 1

[0062] Table 2 below further explains the units of the above parameters:

[0063]

[0064] Table 2

[0065] Back pressure: The inlet of the bladeless fan is a mesh air inlet. In order to consider the pressure loss in the inlet section and improve the work capacity of the fan, it is considered to set an inlet and outlet resistance difference, namely back pressure.

[0066] Wind pressure: the effective energy obtained by unit volume of gas passing through the fan.

[0067] Output power = (outlet total pressure - inlet total pressure) * volume flow rate = 381.7 * 158.2 / 3600 = 16.8

[0068] Input power = (speed * π * impeller torque) / 30 = 5500 * 3.14 * 0.0405424 / 30 = 23.4

[0069] Full voltage efficiency = output power / input power = 71.8%

[0070] Simulation conclusion: Under the condition of 5500rpm, after multiple tests on back pressure and input power, it is found that the efficiency of the wind wheel in this embodiment can reach up to 70%. The air volume of the air outlet of the base of the mixed flow wind wheel is increased from 170m 3 / h can be increased to a maximum of 196m 3 / h.

[0071] The specific forming process of the mixed flow wind wheel blade 2 is described below. Figure 3 and Figure 4 As shown, the blade shaping in this embodiment adopts the method of angle-conformal transformation, such as Figure 3As shown in the figure, the splitting angle is 10°. On the middle surface, the curve intersecting with the outer surface of the hub 1 is taken as the lower end line b, the outermost curve of the middle surface away from the hub 1 is taken as the upper end line a, and any curve between the upper end line a and the lower end line b is taken as the middle end line c. The above-mentioned splitting angle line and the upper end line a, middle end line c, and lower end line b respectively generate splitting intersections, as shown in FIG. Figure 4 As shown, in this embodiment, only the lower end line b is taken as an example, the number of segmentation intersections is 11, corresponding to points 1'-11', and a projection surface s is made through the central axis L1. The method of projecting the projection surface s is based on the design rules in the commonly used angle-preserving transformation, which will not be elaborated here. For the clarity of the subsequent explanation, the three-dimensional coordinate system XYZ is also defined in this embodiment, and the coordinate origin is point O in the figure. The upper end line a, the middle end line c, and the lower end line b selected on the middle surface 23 are sequentially projected onto the projection surface s in turn. The projections of the above segmentation intersections correspond to points 1"-11", and the coordinates of the above segmentation intersections on the two-dimensional projection surface are defined as X and Y. In this embodiment, the coordinate X corresponds to the value on the OZ axis in the XYZ coordinate system, and the coordinate Y corresponds to the value on the OY axis in the XYZ coordinate system. The ratios of the above coordinate values ​​to the diameter R of the mixed flow wind wheel are defined as x and y, respectively, to obtain the parameters in Table 3:

[0072]

[0073]

[0074] Table 3

[0075] The blade profile of the blade 2 described above has better flow-guiding capability, which can reduce the kinetic energy loss along the airflow during the rotation process, thereby increasing the final air output.

[0076] Among them, the x corresponding to the lower end line satisfies [0.05, 0.35], and the y satisfies [0.045, 0.30]; the x corresponding to the middle end line satisfies [0.01, 0.35], and the y satisfies [0.15, 0.35]; the x corresponding to the upper end line satisfies [0.005, 0.30], and the y satisfies [0.24, 0.40]. The above relationship determines the basic blade shape of blade 2. When the diameter of the mixed flow wind wheel changes, the shape of the corresponding blade 2 can be enlarged or reduced proportionally.

[0077] like Figure 5 As shown in , the blade wrap angle σ is [80°, 100°]. In this embodiment, the blade wrap angle σ is 90°. The blade 2 under the above wrap angle has a strong working capacity and can increase the wind pressure.

[0078] like Figure 2As shown, the end face of the leading edge of the blade includes a straight surface 24 arranged on a side close to the hub 1, and a curved surface 25 connected to the straight surface 24. This structural design is used to reduce the separation of the boundary layer of the airflow at the leading edge of the blade, reduce vortices, and reduce noise.

[0079] Furthermore, the end surface of the trailing edge of the blade is provided with a plurality of tooth-shaped grooves 28. Vortexes are formed between the tooth-shaped grooves 28, which can effectively reduce the horseshoe pits where the pressure surface and the suction surface interact, and reduce aerodynamic vortex noise.

[0080] The blades 2 in this embodiment include a main blade 26 and a secondary blade 27 sandwiched between the two main blades 26. The leading edges of the secondary blades 27 are positioned lower than the leading edges of the main blades 26 in the axial direction of the hub 1. The main blades 26 and secondary blades 27 have the same shape, differing only in the position of their leading edges. It should be noted that the aforementioned research in this embodiment focuses on the main blades 26. Of course, the same conclusions can be drawn using the secondary blades 27 as the research subject.

[0081] Of course, in this embodiment, the plurality of blades 2 are equally spaced in the circumferential direction at the same height of the hub 1. The equally spaced arrangement ensures uniform flow distribution by each blade, which in turn ensures the stability and consistency of the fluid pressure applied to each blade, thereby effectively ensuring the service life of the guide vane.

[0082] Example 2

[0083] like Figure 7 As shown, a fan assembly provided in this embodiment includes: the mixed flow fan wheel described in the above embodiment 1, and a drive motor 3, wherein the mixed flow fan wheel is installed on the motor shaft of the drive motor 3.

[0084] This embodiment also includes a shell 4 covering the mixed flow wind wheel, and a fluid channel is constructed between the inner side wall of the shell 4 and the outer surface of the hub 1, and the blades 2 are accommodated in the fluid channel. In this embodiment, the shell 4 is directly integrally formed on the mixed flow wind wheel.

[0085] Example 3

[0086] like Figures 8 to 9 As shown, a power system provided in this embodiment includes: the fan assembly described in the above embodiment 2.

[0087] like Figure 8 The exploded diagram in FIG shows the basic components of the power system. H in the figure represents a mixed flow impeller, which is mounted on the motor shaft of the drive motor 3. The outer cover of the drive motor 3 is provided with a motor housing 7. The motor housing 7 not only supports the installation of the motor, but also reduces the noise caused by the vibration of the drive motor.

[0088] This embodiment also includes a diffuser 8, which is arranged above the mixed flow impeller H. The high-speed rotating airflow coming out of the mixed flow impeller H enters the diffuser 8 and becomes an airflow flowing along the axial direction. The diffuser 8 is a hollow shell structure, and the above-mentioned motor shell 7 is deeply installed in the interior of the diffuser 8 to achieve a compact structural design.

[0089] This embodiment also includes an upper shell 6 and a lower shell 9, which are locked together by a locking member 5, wherein an air guide duct can be formed between the inner side wall of the upper shell 7 and the outer side surface of the diffuser 8.

[0090] Example 4

[0091] This embodiment provides a fan, specifically a bladeless fan, which includes the power system described in the above embodiment 3 and has all its technical advantages, which will not be described in detail here.

[0092] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A mixed flow wind wheel comprising a hub (1) and a plurality of blades (2) arranged in a circumferential direction of the hub (1), wherein the blades (2) have a suction surface (21) and a pressure surface (22), and is characterized in that: A point equidistant between the suction surface (21) and the pressure surface (22) is defined as a mid-surface (23); A cylindrical surface M formed with the rotation axis of the hub (1) as the central axis intersects with the middle surface (23), and an intersection point between the cylindrical surface M and the end line N of the blade leading edge of the middle surface (23) is defined as an air inlet intersection point A, and an intersection point between the cylindrical surface M and the end line P of the blade trailing edge of the middle surface (23) is defined as an air outlet intersection point B, and a blade profile curve Q of the blade (2) is drawn through points A and B; A tangent line to the blade profile curve Q passing through point A is a first tangent line, and a tangent line to the axial section of the cylindrical surface M passing through point A is a second tangent line. The angle between the first tangent line and the second tangent line is the inlet tangent angle α, and the value of α is [25°, 40°]. The tangent line of the blade profile curve Q through point B is the third tangent line, and the tangent line of the axial section of the cylindrical surface M through point B is the fourth tangent line. The angle between the third tangent line and the fourth tangent line is the outlet angle β, and the value of β is [30°, 40°].

2. The mixed flow wind wheel according to claim 1, characterized in that: The air inlet angle α is 32°, and the air outlet angle β is 35°.

3. The mixed flow wind wheel according to claim 1, characterized in that: On the middle surface (23), the curve intersecting the middle surface with the outer surface of the hub (1) is taken as the lower end line, the outermost curve of the middle surface (23) away from the hub (1) is taken as the upper end line, and any curve between the upper end line and the lower end line is taken as the middle end line, the conformal transformation angle is defined as 10°, the coordinates of the intersection on the two-dimensional projection surface are defined as (X, Y), and the ratios of the coordinate values ​​to the diameter of the mixed flow wind wheel are defined as x and y, respectively, wherein, The x corresponding to the lower end line satisfies [0.05, 0.35], and the y satisfies [0.045, 0.30]; The x corresponding to the midline satisfies [0.01, 0.35], and the y satisfies [0.15, 0.35]; The x corresponding to the upper end line satisfies [0.005, 0.30], and the y satisfies [0.24, 0.40].

4. The mixed flow wind wheel according to any one of claims 1 to 3, characterized in that: The blade wrap angle σ is [80°, 100°].

5. The mixed flow wind wheel according to claim 4, characterized in that: The blade wrap angle σ is 90°.

6. The mixed flow wind wheel according to claim 4, characterized in that: The end surface of the leading edge of the blade comprises a straight surface (24) arranged on a side close to the hub (1), and a cambered surface (25) connected to the straight surface (24).

7. The mixed flow wind wheel according to claim 5, characterized in that: A plurality of tooth-shaped grooves (28) are provided on the end surface of the trailing edge of the blade.

8. The mixed flow wind wheel according to claim 1, characterized in that: The blade (2) comprises a main blade (26) and an auxiliary blade (27) sandwiched between the two main blades (26), and the leading edge of the auxiliary blade (27) is arranged lower than the leading edge of the main blade (26) in the axial height of the hub (1).

9. The mixed flow wind wheel according to claim 8, characterized in that: The plurality of blades (2) are distributed at equal intervals in the circumferential direction at the same height of the hub (1).

10. A fan assembly, characterized in that: include: The mixed flow wind wheel according to any one of claims 1 to 9; A drive motor (3), wherein the mixed flow fan is arranged on a motor shaft of the drive motor (3).

11. The fan assembly according to claim 10, characterized in that: It also includes a shell (4) that is covered on the mixed flow wind wheel, a fluid channel is constructed between the inner side wall of the shell (4) and the outer surface of the hub (1), and the blades (2) are accommodated in the fluid channel.

12. The fan assembly according to claim 11, characterized in that The shell (4) is integrally formed on the mixed flow impeller.

13. A power system, characterized in that: include: The mixed flow wind wheel according to any one of claims 1 to 9; Or the fan assembly according to any one of claims 10 to 12.

14. A fan, characterized in that: include: The power system as claimed in claim 13.

15. The fan according to claim 14, characterized in that The fan is a bladeless fan.

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