Fan and fan control method

Abstract

A fan (100). A first fan blade (10) comprises first blades (11), a second fan blade (20) comprises second blades (21), the first fan blade (10) and the second fan blade (20) are coaxially arranged, the first fan blade (10) is located in front of the second fan blade (20), diameter D1 of the first fan blade (10) is greater than diameter D2 of the second fan blade (20), and blade trailing edges of the first blades (11) and blade leading edges of the second blades (21) are arranged adjacent to each other in the axial direction.

Description

Fan and fan control method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application number "202311644226.0" filed by Guangdong Midea Environmental Electrical Appliance Manufacturing Co., Ltd. on November 30, 2023, with application name "Fan and Fan Control Method". Technical Field

[0003] The present application relates to the field of household electrical appliances, and in particular to a fan and a method for controlling the fan. Background Art

[0004] In related technologies, floor fans and circulating fans are two common types of fans, but the air outlet forms of floor fans and circulating fans are different. Floor fans can achieve dispersed air outlet (i.e., scattered wind), while circulating fans can achieve more concentrated air outlet (i.e., gathered wind), which can provide different user experiences.

[0005] However, as people's living standards continue to improve, consumers' requirements for fans are also getting higher and higher, resulting in the single air outlet mode of floor fans and circulation fans being unable to meet usage needs. Summary of the Invention

[0006] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a fan that can achieve both dispersed and concentrated air output, providing a better user experience.

[0007] An embodiment of the present application provides a fan, comprising: a first fan blade and a second fan blade, the first fan blade having a first blade, the first fan blade and the second fan blade being coaxially arranged, the first fan blade being located in front of the second fan blade, the first fan blade and the second fan blade having opposite rotation directions, the second fan blade having a second blade, the diameter D1 of the first fan blade being greater than the diameter D2 of the second fan blade, and the trailing edge of the first blade and the leading edge of the second blade being axially adjacent to each other.

[0008] According to the fan of the embodiment of the present application, the rotation directions of the first fan blade and the second fan blade are opposite, and the diameter of the first fan blade is larger than that of the second fan blade. The first fan blade and the second fan blade can be controlled to rotate simultaneously or individually to achieve air volume adjustment, or a speed difference is created between the first fan blade and the second fan blade to achieve wind gathering mode and wind dispersion mode, so that the fan of the present application can have the wind outlet characteristics of a circulating fan and a floor fan, enrich the wind outlet modes, meet different usage needs, and improve the usage experience.

[0009] According to an embodiment of the present application, the fan includes: a first fan blade and a second fan blade, the first fan blade has a first blade, the first fan blade and the second fan blade are coaxially arranged, the first fan blade is located in front of the second fan blade, the second fan blade has a second blade, the diameter D1 of the first fan blade is greater than the diameter D2 of the second fan blade, and the trailing edge of the first blade and the leading edge of the second blade are axially adjacent to each other.

[0010] According to some embodiments of the present application, the diameter D1 of the first fan blade and the diameter D2 of the second fan blade satisfy: 0.4≤D2 / D1≤0.9.

[0011] In some embodiments, an extending direction from the leading edge of the first blade to the trailing edge of the blade is opposite to an extending direction from the leading edge of the second blade to the trailing edge of the blade.

[0012] According to some embodiments of the present application, a distance L1 between a leading edge of the first blade and a trailing edge of the second blade satisfies: 0<L1<80 mm.

[0013] In some embodiments, the fan further includes: a power source, wherein the power source is used to drive the first blade and the second blade to rotate.

[0014] In some embodiments, the power source includes: a first motor and a second motor, the first motor is connected to the power of the first fan blade, the second motor is connected to the power of the second fan blade, and is suitable for controlling the rotation speed of the first fan blade and the second fan blade respectively.

[0015] According to some embodiments of the present application, the fan further includes: an air guide tube having a first mounting portion and a second mounting portion, the first mounting portion being used to mount the first motor, and the second mounting portion being used to mount the second motor.

[0016] In some embodiments, the fan further includes: an air outlet mesh cover, which is arranged on the air outlet side of the first fan blade and has a first grille ring and a second grille ring arranged in sequence in the radial direction, the first grille ring is used to diverge airflow away from the rotation axis, and the second grille ring is used to gather airflow toward the rotation axis.

[0017] In some embodiments, the ratio of the outer diameter D3 of the first grille ring to the diameter D1 of the first blade satisfies: 1≤D3 / D1≤1.1, and the ratio of the outer diameter D4 of the second grille ring to the diameter D2 of the second blade satisfies: 1≤D4 / D2≤1.1.

[0018] In some embodiments, the angles formed between the plurality of first guide grilles in the first grille ring and the axis are 5° to 90°, and the angles formed between the plurality of second guide grilles in the second grille ring and the axis are 0° to 5°.

[0019] In some embodiments, the thickness of the windward side of the first guide grille is W1, the thickness of the windward side of the first guide grille is W2, and the following conditions are satisfied: 1.5 mm ≤ W1 ≤ 5 mm, 1.5 mm ≤ W2 ≤ 5 mm.

[0020] According to some embodiments of the present application, a width L2 of the first guide grille satisfies: 4 mm ≤ L2 ≤ 15 mm.

[0021] The present application also provides a fan control method, including:

[0022] Obtaining an air outlet mode of the fan, wherein the air outlet mode includes a scattered air mode and a concentrated air mode;

[0023] According to the air outlet mode, the rotational speeds of the first fan blade and the second fan blade are adjusted so that there is a rotational speed difference between the first fan blade and the second fan blade.

[0024] In some embodiments, adjusting the rotational speeds of the first and second fan blades according to the air outlet mode specifically includes:

[0025] In the wind dispersion mode, the rotation speed of the first blade is lower than the rotation speed of the second blade;

[0026] In the wind gathering mode, the rotation speed of the second fan blade is lower than the rotation speed of the first fan blade.

[0027] Furthermore, the wind dispersion mode and the wind gathering mode both have multiple gears, and the control method further includes:

[0028] In the wind dispersion mode, the speed difference between the first fan blade and the second fan blade is 100 rpm to 250 rpm;

[0029] In the wind gathering mode, the speed difference between the first fan blade and the second fan blade is 500 r / min to 800 r / min, and is positively correlated with the gear position.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0032] FIG1 is a perspective schematic diagram of a fan according to a first embodiment of the present application;

[0033] FIG2 is a schematic front view of a fan according to the first embodiment of the present application;

[0034] FIG3 is an exploded schematic diagram of a fan according to the first embodiment of the present application;

[0035] FIG4 is a schematic diagram of the cooperation between the first blade and the second blade of the fan according to an embodiment of the present application;

[0036] FIG5 is a perspective schematic diagram of a fan according to a second embodiment of the present application;

[0037] FIG6 is a schematic front view of a fan according to a second embodiment of the present application;

[0038] FIG7 is an exploded schematic diagram of a fan according to a second embodiment of the present application;

[0039] FIG8 is a schematic diagram of an air outlet grille according to a second embodiment of the present application at an angle;

[0040] FIG9 is a schematic diagram of the air outlet grille according to the second embodiment of the present application from another angle;

[0041] FIG10 is a schematic cross-sectional view of an air outlet grille according to a second embodiment of the present application;

[0042] FIG11 is a schematic cross-sectional view of a fan according to a second embodiment of the present application;

[0043] FIG12 is an exploded schematic diagram of a fan according to a third embodiment of the present application;

[0044] FIG13 is a schematic diagram of a first blade according to a third embodiment of the present application;

[0045] 14 is a simulated airflow streamline diagram and a simulated airflow cross-sectional velocity distribution diagram of the airflow of the fan in the wind gathering mode according to an embodiment of the present application;

[0046] 15 is a simulated airflow streamline diagram and a simulated airflow cross-sectional velocity distribution diagram of the airflow of the fan in the scattered wind mode according to an embodiment of the present application;

[0047] FIG16 is a schematic diagram of an airflow path of a fan in a wind-gathering mode according to an embodiment of the present application;

[0048] FIG17 is a schematic diagram of an airflow path of a fan in a wind dispersion mode according to an embodiment of the present application;

[0049] FIG18 is a schematic diagram of a fan control method according to an embodiment of the present application. DETAILED DESCRIPTION

[0050] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0051] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0052] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. Furthermore, in the description of this application, unless otherwise specified, "plurality" means two or more.

[0053] The fan 100 according to an embodiment of the present application is described below with reference to FIG. 1 to FIG. 18 .

[0054] As shown in FIG. 1 , FIG. 2 , FIG. 5 and FIG. 6 , the fan 100 includes a base and structures such as an air outlet assembly, an air inlet mesh cover 70 , and an air outlet mesh cover 60 disposed on the base.

[0055] Referring to Figures 3, 7 and 12, the fan 100 includes: a first fan blade 10 and a second fan blade 20, the first fan blade 10 has a first blade 11, the second fan blade 20 has a second blade 21, the first fan blade 10 and the second fan blade 20 are coaxially arranged, the first fan blade 10 is located in front of the second fan blade 20, the rotation directions of the first fan blade 10 and the second fan blade 20 are opposite, the diameter D1 of the first fan blade 10 is greater than the diameter D2 of the second fan blade 20, and the trailing edge of the first blade 11 and the leading edge of the second blade 21 are axially adjacent to each other.

[0056] Multiple first blades 11 are arranged in sequence along the circumferential direction, and multiple second blades 21 are arranged in sequence along the circumferential direction. The first fan blades 10 can rotate to drive the surrounding gas flow during the rotation process, thereby forming an airflow with a certain flow rate, and the second fan blades 20 can also rotate to drive the surrounding gas flow during the rotation process, thereby forming an airflow with a certain flow rate.

[0057] It is defined that the leading edge of the blade is located on the air inlet side of the fan blade, and the trailing edge of the blade is located on the air outlet side of the fan blade. Correspondingly, the trailing edge of the first fan blade 10 and the leading edge of the second fan blade 20 are arranged adjacent to each other in the axial direction, so that at least part of the airflow with a certain flow rate generated by the first fan blade 10 can further flow through the second fan blade 20, and can flow out after being decelerated or accelerated by the second fan blade 20.

[0058] The rotation directions of the first fan blade 10 and the second fan blade 20 are different, such as the first fan blade 10 rotates clockwise and the second fan blade 20 rotates counterclockwise, or the first fan blade 10 rotates counterclockwise and the second fan blade 20 rotates clockwise. Therefore, the rotation speeds of the first fan blade 10 and the second fan blade 20 can be the same to increase the air supply distance. Only one of the fan blades can be rotated, such as only the first fan blade 10 or only the second fan blade 20 to adjust the air volume.

[0059] The first blade 10 and the second blade 20 can be made to rotate at the same time, and at different speeds. For example: the speed of the first blade 10 is higher than that of the second blade 20. At this time, the speed of the first blade 10 is fast, and the speed of the second blade 20 is slow. After the airflow is initially accelerated by the first blade 10, most of the airflow can flow out from the outer area of ​​the second blade 20 (the non-overlapping area of ​​the axial projection of the first blade 10 and the axial projection of the second blade 20 is defined as the outer area). The air outlet area is large and the airflow velocity is low. The second blade 20 rotates at a low speed, which can be applied to the middle area adjacent to the rotation axis of the fan 100 (the axial projection area where the second blade 20 is located is defined as the middle area). The second fan blades 20 can perform secondary acceleration on the airflow to increase the air outlet speed while reducing the air outlet area, thereby achieving wind gathering and increasing the airflow speed so that the airflow can act on a farther area or position in the wind gathering mode.

[0060] The present application sets a first fan blade 10 and a second fan blade 20 so that the rotation directions of the first fan blade 10 and the second fan blade 20 are different. The air outlet side of the first fan blade 10 is arranged adjacent to the air inlet side of the second fan blade 20, and the diameter of the second fan blade 20 is smaller than the diameter of the first fan blade 10. Therefore, there is a speed difference between the first fan blade 10 and the second fan blade 20, and one of the first fan blade 10 and the second fan blade 20 rotates at a high speed and the other rotates at a low speed, so as to realize switching between a large-scale wind dispersion mode in the radially outer external area and a small-scale wind gathering mode in the radially inner middle area, thereby enriching the air outlet mode of the fan 100 and improving the user experience.

[0061] In the wind gathering mode, the airflow passes through the first fan blade 10 and is initially accelerated, and then enters the second fan blade 20 for secondary acceleration. The airflow velocity is high and the air outlet area is small, which can simulate the circulating fan outlet. In the wind dispersion mode, the airflow passes through the first fan blade 10 and is initially accelerated, and most of the airflow flows out directly from the external area. The second fan blade 20 rotates at a low speed, which can supplement the airflow in the middle area, so that the air outlet area of ​​the fan 100 is large and the gas flow rate is low, which can simulate the floor fan outlet.

[0062] Of course, the implementation of the wind gathering mode and the wind dispersion mode of the fan 100 in the embodiment of the present application is not limited to this. In other embodiments, the fan 100 includes: a first fan blade 10 and a second fan blade 20, the first fan blade 10 has a first blade 11, the second fan blade 20 has a second blade 21, the first fan blade 10 and the second fan blade 20 are coaxially arranged, the first fan blade 10 is located in front of the second fan blade 20, the diameter D1 of the first fan blade 10 is greater than the diameter D2 of the second fan blade 20, and the trailing edge of the first blade 11 and the leading edge of the second blade 21 are axially adjacent.

[0063] Thus, the air outlet side of the first fan blade 10 is arranged adjacent to the air inlet side of the second fan blade 20, and the diameter of the second fan blade 20 is smaller than the diameter of the first fan blade 10, so that there is a speed difference between the first fan blade 10 and the second fan blade 20, and one of the first fan blade 10 and the second fan blade 20 rotates at high speed and the other rotates at low speed, so as to realize switching between a large-scale wind dispersion mode in the radially outer external area and a small-scale wind gathering mode in the radially inner middle area, enriching the air outlet mode of the fan 100 and improving the user experience.

[0064] Refer to Figure 14. In Figure 14, Figures a and b show the simulated airflow streamlines at different angles when the fan 100 is in the wind gathering mode. It can be seen from Figures a and b that in the wind gathering mode, the airflow generated by the fan 100 is in a bundled shape and concentrated on the middle area corresponding to the second fan blade 20. Figures c and d show the simulated airflow cross-sectional velocity distribution diagrams when the fan 100 is in the wind gathering mode. It can be seen from Figures c and d that the airflow velocity in the middle area is faster, and the airflow velocity in the area adjacent to the rotation axis is fast and the area is small.

[0065] Refer to Figure 15. In Figure 15, Figures e and f show the simulated airflow streamlines at different angles when the fan 100 is in the scattered wind mode. It can be seen from Figures e and f that in the scattered wind mode, the airflow generated by the fan 100 is divergent and covers most of the radial area of ​​the fan 100 corresponding to the first blade 10 and the second blade 20, that is, the middle area plus the outer area. Figures g and h show the simulated airflow cross-sectional velocity distribution diagram when the fan 100 is in the scattered wind mode. It can be seen from Figures g and h that the overall airflow velocity is slower, the air outlet area is large, and the gas flow rate is small.

[0066] According to the fan 100 of the embodiment of the present application, the rotation directions of the first fan blade 10 and the second fan blade 20 are opposite, and the diameter of the first fan blade 10 is larger than that of the second fan blade 20. The first fan blade 10 and the second fan blade 20 can be controlled to rotate simultaneously or individually to achieve air volume adjustment, or a speed difference is created between the first fan blade 10 and the second fan blade 20 to achieve a wind gathering mode and a wind dispersion mode, so that the fan 100 of the present application can have the air outlet characteristics of a circulating fan and a floor fan, enrich the air outlet modes, meet different usage needs, and improve the usage experience.

[0067] The structure of the fan 100 of the embodiment of the present application is not limited to this. In the first embodiment, the present application sets a first fan blade 10 and a second fan blade 20, and makes the diameter of the first fan blade 10 larger than the diameter of the second fan blade 20, and then through the speed difference between the first fan blade 10 and the second fan blade 20, the wind dispersion mode and the wind gathering mode can be realized accordingly. In the second embodiment, an air outlet mesh cover 60 with multiple grille rings can be further set to cooperate with the first fan blade 10 and the second fan blade 20 to improve the air outlet effect of the wind gathering mode and the air dispersion mode. In the third embodiment, on the basis of the first embodiment or the second embodiment, the first fan blade 10 can be further set as a double-layer fan blade structure to enhance the air outlet effect of the fan 100.

[0068] The inside and outside directions involved in this application are relative concepts. Relatively speaking, the direction adjacent to the rotation axis is inside, and the direction away from the rotation axis is outside. The front and back directions are also relative concepts. The second fan blade 20 is located behind the first fan blade 10, and the first fan blade 10 is located in front of the second fan blade 20.

[0069] 1 , 2 and 3 , in the first embodiment, the fan 100 is provided with a first blade 10 and a second blade 20 of different diameters, and is equipped with a conventional air outlet mesh cover 60, as shown in FIG5 , 6 , 7 , 8 , 9 , 10 and 11 . In the second embodiment, while providing the first blade 10 and the second blade 20 of different diameters, an air outlet mesh cover 60 having at least two grille rings is further provided, as shown in FIG12 and 13 . In the third embodiment, the first blade 10 and the second blade 20 of different diameters can be provided, and the first blade 10 is constructed as a double-layer blade structure. Corresponding to the third embodiment, the air outlet mesh cover 60 can be a conventional mesh cover or an air outlet mesh cover 60 with the same structure as the second embodiment.

[0070] In the second embodiment, the air outlet assembly includes a first fan blade 10 and a second fan blade 20, and the fan 100 also includes: an air outlet mesh cover 60, which is arranged on the air outlet side of the second fan blade 20 and has a first grille ring 61 and a second grille ring 62 arranged in sequence in the radial direction. The first grille ring 61 is used to diverge airflow away from the rotation axis, and the second grille ring 62 is used to gather airflow toward the rotation axis.

[0071] As shown in Figures 8, 9 and 10, the second grille ring 62 is arranged closer to the rotation axis than the first grille ring 61, corresponding to the middle area where the second fan blade 20 is located. The first grille ring 61 is arranged farther away from the rotation axis than the second grille ring 62, corresponding to the outer area where the first fan blade 10 and the second fan blade 20 do not overlap in axial projection.

[0072] 16 and 17 , the first grille ring 61 can guide the airflow to flow outward relative to the axis of rotation, and the second grille ring 62 can guide the airflow to converge inward relative to the axis of rotation. For example, the first grille ring 61 can guide the airflow flowing outward at an angle of 20° along the axis of rotation to flow outward at an angle of 25° or 30°, etc., to improve the wind dispersion effect, while the second grille ring 62 can convert the airflow originally flowing outward at an angle of 20° along the axis of rotation into an airflow flowing outward at an angle of 10° or 0°, to achieve the convergence of the airflow and improve the wind gathering effect.

[0073] In the wind gathering mode, the rotation speed of the second fan blade 20 is higher than that of the first fan blade 10. After the airflow is initially accelerated by the first fan blade 10, it flows into the second fan blade 20. The second fan blade 20 further accelerates the airflow, and it flows out after being rectified by the second grille ring 62 of the air outlet mesh cover 60. The rectifying effect of the second grille ring 62 is to gather the airflow toward the axis of rotation, which can effectively speed up the airflow speed and further reduce the air outlet area to improve the wind gathering effect.

[0074] In the wind dispersion mode, the rotation speed of the first fan blade 10 is higher than the rotation speed of the second fan blade 20. After the airflow is accelerated by the first fan blade 10, most of the airflow directly enters the external area. The external area corresponds to the first grille ring 61, and the first grille ring 61 is used to disperse the airflow away from the rotation axis. It can further disperse the airflow so that the airflow flows outward at a certain angle to the rotation axis, further increasing the air outlet area and reducing the airflow speed to improve the wind dispersion effect.

[0075] According to the fan 100 of the embodiment of the present application, by setting an air outlet mesh cover 60, and making the air outlet mesh cover 60 have at least a first grille ring 61 for dispersing airflow away from the rotation axis and a second grille ring 62 for gathering airflow toward the rotation axis, it is possible to realize a wind dispersion mode and a wind gathering mode to enrich the air outlet mode and improve the user experience. At the same time, during the operation of the fan 100, the airflow in the wind dispersion mode can be made more divergent, the air outlet uniformity can be improved, and the airflow in the wind gathering mode can be made more concentrated, the wind gathering effect can be improved.

[0076] In the third embodiment, the first fan blade 10 has a first blade 11, the first blade 11 has a first blade area 111 and a second blade area 112 arranged in sequence along the radial direction, and the second fan blade 20 has a second blade 21, and the axial projection of the second blade 21 at least partially overlaps with that of the second blade area 112.

[0077] 12 and 13 , the second blade region 112 is at least partially opposite to the second blade 21 in the axial direction, and the first blade region 111 is located outside the axial projection range of the second blade 21 .

[0078] In the wind gathering mode, the rotation speed of the second fan blade 20 is higher than that of the first fan blade 10. After the airflow is initially accelerated by the first blade area 111 and the second blade area 112, it flows into the second fan blade 20. The second fan blade 20 further accelerates the airflow, which can effectively increase the airflow speed and further reduce the air outlet area to improve the wind gathering effect.

[0079] In the scattered wind mode, the rotation speed of the first fan blade 10 is higher than the rotation speed of the second fan blade 20. After the airflow is accelerated through the first blade area 111 and the second blade area 112, most of the airflow generated by the first blade area 111 directly enters the external area, and the airflow generated by the second blade area 112 flows into the second fan blade 20. The second fan blade 20 rotates further to generate supplementary airflow to supplement the airflow in the middle area, so that the air outlet in the scattered wind mode is more uniform. Both the external area and the middle area have scattered wind airflow with a slower gas flow rate, which effectively reduces the airflow speed to improve the scattered wind effect.

[0080] According to the fan 100 of the embodiment of the present application, the rotation directions of the first fan blade 10 and the second fan blade 20 are opposite, the diameter of the first fan blade 10 is larger than that of the second fan blade 20, the first blade area 111 of the first fan blade 10 is located outside the second fan blade 20, and the second blade area 112 is arranged corresponding to the second fan blade 20. The first fan blade 10 and the second fan blade 20 can be controlled to rotate simultaneously or separately to achieve air volume adjustment, or a speed difference can be created between the first fan blade 10 and the second fan blade 20 to achieve a wind gathering mode and a wind dispersion mode, and the second blade area 112 can be used to effectively achieve air volume supplementation or airflow acceleration, so that the fan 100 of the present application can have the air outlet characteristics of a circulating fan and a floor fan, enrich the air outlet mode, meet different usage needs, and improve the usage experience.

[0081] As shown in Figures 4 and 13, according to some embodiments of the present application, the diameter D1 of the first fan blade 10 and the diameter D2 of the second fan blade 20 satisfy: 0.4≤D2 / D1≤0.9, and the diameter of the second blade area 112 is less than or equal to the diameter of the second fan blade 20, and the diameter of the first blade area 111 is equal to the diameter of the first fan blade 10.

[0082] The diameter ratio of the second blade 20 to the first blade 10 may be 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.

[0083] When the diameter ratio of the second fan blade 20 to the first fan blade 10 is too small, the second fan blade 20 is smaller. In the wind gathering mode, the airflow is gathered in the area with too small an air outlet area. The air outlet area is too small, which affects the user experience. In the wind dispersion mode, the airflow supplement effect in the middle area is also poor. When the diameter ratio of the second fan blade 20 to the first fan blade 10 is too large, the second fan blade 20 is too large. In the wind gathering mode, the airflow is gathered in the area with too large an air outlet area, resulting in poor wind gathering effect. In the wind dispersion mode, the area for airflow supplementation is too large, and the area of ​​the external area for dispersing the air is too small, resulting in poor wind dispersion effect, which also reduces the user experience.

[0084] By making the diameter ratio of the second blade 20 to the first blade 10 fall within the range of 0.4 to 0.9, the sizes of the first blade 10 and the second blade 20 are made more reasonable. The more reasonably sized first blade 10 and the second blade 20 can take into account both the wind gathering effect and the wind dispersion effect, so that the fan 100 has better wind output effects in both the wind gathering mode and the wind dispersion mode, thereby improving the user experience.

[0085] The diameter of the first blade area 111 is greater than or equal to the diameter of the first fan blade 10, and the diameter of the second blade area 112 is the same as the diameter of the second fan blade 20. The second blade area 112 can assist the second fan blade 20 in supplementing the airflow, and the diameter of the second blade area 112 is less than or equal to the diameter of the first fan blade 10. While improving the uniformity of the air outlet in the scattered wind mode, it can avoid the diameter of the second blade area 112 being too large, causing turbulence, so as to improve the air outlet effect.

[0086] As shown in Figures 11 and 13, in some embodiments, the extension direction from the leading edge to the trailing edge of the blade of the first sub-blade 1111 in the first blade area 111 is opposite to the extension direction from the leading edge to the trailing edge of the blade of the second blade 21, and the extension direction from the leading edge to the trailing edge of the blade of the second sub-blade 1121 in the second blade area 112 is consistent with the extension direction from the leading edge to the trailing edge of the blade of the first sub-blade 1111 in the first blade area 111.

[0087] The first sub-blade 1111 of the first blade area 111 and the second sub-blade 1121 of the second blade area 112 can be arranged continuously, and the first fan blade 10 can have a first circular ring and a second circular ring arranged concentrically, the radial inner end of the second sub-blade 1121 is connected to the first circular ring, the radial outer end of the second sub-blade 1121 is connected to the inner wall of the second circular ring, the radial inner end of the first sub-blade 1111 is connected to the outer wall of the second circular ring, and the inner diameter of the second circular ring is the same as the diameter of the second blade 21, so that the diameter of the second blade area 112 is the same as the diameter of the second fan blade 20, and thus the rotation direction of the first sub-blade 1111 is opposite to the rotation direction of the second blade 21, and the rotation direction of the second sub-blade 1121 is the same as that of the first sub-blade 1111.

[0088] The first fan blade 10 rotates clockwise or counterclockwise to disturb the airflow, and the corresponding second fan blade 20 rotates counterclockwise or clockwise to disturb the airflow, so that in the wind dispersion mode, the airflow generated by the first fan blade 10 can diverge outward along the rotation axis, and in the wind gathering mode, the airflow generated by the first fan blade 10 can converge inward along the rotation axis, thereby improving the airflow guiding effect and making the wind outlet effect better in both the wind gathering mode and the wind dispersion mode.

[0089] In the first embodiment, the rotation direction of the first blade 11 is opposite to that of the second blade 21, the first fan blade 10 has a first ring, the inner end of the first blade 11 is connected to the first ring, and at least part of the first blade 11 is opposite to the second fan blade 20. In the third embodiment, the first sub-blade 1111 is located in the outer area, and the second sub-blade 1121 is located in the middle area and at least partially overlaps with the second fan blade 20. The airflow can be disturbed in opposite directions by the first fan blade 10 and the second fan blade 20 to achieve a wind gathering mode and a wind dispersion mode.

[0090] According to some embodiments of the present application, the distance L1 between the trailing edge of the first sub-blade 1111 of the first blade area 111 and the leading edge of the second blade 21 satisfies: 0<L1<80mm (that is, the first blade 11 or the first blade area 111 is spaced apart from the second blade 21 in the front-to-back direction).

[0091] As shown in FIG11 , from the cross-sectional view of the fan 100 , it can be seen that the distance between the trailing edge of the first blade 11 in the first embodiment or the trailing edge of the first sub-blade 1111 in the third embodiment and the leading edge of the second blade 21 is in the range of 0 to 80 mm.

[0092] The axial distance between the first blade 11 and the second blade 21 is 10mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, etc., so that the distance between the first blade 11 and the second blade 21 is more reasonable. On the one hand, the space occupied by the fan 100 can be reduced; on the other hand, the distance between the first blade 11 and the second blade 21 is more reasonable, and the flow path of the airflow generated by the first blade 10 flowing into the second blade 20 or directly flowing out of the fan 100 is shorter, which can improve the wind outlet effect and the coordination effect between the first blade 10 and the second blade 20, and further improve the wind outlet effect of the fan 100 in the wind gathering mode and the wind dispersion mode.

[0093] The first blade 11 or the first blade area 111 is spaced apart from the second blade 21 in the front-to-back direction, which can ensure that the airflow generated by the first blade 10 is initially accelerated by the first blade 10 and then flows to the external area or flows to the middle area where the second blade 20 is located. This can avoid the turbulence effect of the second blade 20 interfering with the turbulence effect of the first blade 10 when both the first blade 10 and the second blade 20 are rotating, thereby improving the air outlet effect of the fan 100.

[0094] As shown in FIG. 3 , FIG. 7 and FIG. 12 , in some embodiments, the fan 100 further includes a power source, the power source being configured to drive the first blade 10 and the second blade 20 to rotate.

[0095] The power source may include: a first motor 30 and a second motor 40, the first motor 30 is connected to the first fan blade 10, and the second motor 40 is connected to the second fan blade 20, and is suitable for controlling the rotation speed of the first fan blade 10 and the second fan blade 20 respectively.

[0096] The first fan blade 10 and the second fan blade 20 can be driven by the first motor 30 and the second motor 40 respectively, so that the speed control of the first fan blade 10 and the second fan blade 20 is simpler and more convenient, and the structure of the fan 100 is simpler.

[0097] Of course, the structure of the power source of the embodiment of the present application is not limited to this. In other embodiments, a motor can also be used to drive the first fan blade 10 and the second fan blade 20 to rotate respectively. The motor drives the first fan blade 10 and the second fan blade 20 respectively through two sets of transmission components, and both sets of transmission components have multiple speed ratios. Based on the required speeds of the first fan blade 10 and the second fan blade 20, the speed ratios of the two sets of transmission components are selected respectively, so as to achieve a speed difference between the first fan blade 10 and the second fan blade 20, and the same technical effect as the first motor 30 and the second motor 40 can also be achieved.

[0098] As shown in Figures 1, 2, 5 and 6, the fan 100 also includes: an air guide tube 50, which has a first mounting portion 51 and a second mounting portion 52. The first mounting portion 51 is used to mount the first motor 30, and the second mounting portion 52 is used to mount the second motor 40.

[0099] The air guide cylinder 50 has an outer cylinder and an inner cylinder, and the inner cylinder and the outer cylinder are connected by several radial rods. The diameter of the outer cylinder is larger than the diameter of the first fan blade 10. A partition can be set in the inner cylinder to define a first mounting portion 51 and a second mounting portion 52 located on both sides of the partition. The motor housing of the first motor 30 can be set in the first mounting portion 51, and the motor shaft is connected to the first fan blade 10 through a coupler or directly. The motor housing of the second motor 40 can be set in the second mounting portion 52, and the motor shaft is connected to the second fan blade 20 through a coupler or directly, so as to drive the first fan blade 10 and the second fan blade 20 to rotate through the first motor 30 and the second motor 40 respectively.

[0100] By providing the air guide tube 50, the assembly structure of the first motor 30, the second motor 40, the first fan blade 10 and the second fan blade 20 is simpler, the overall arrangement of the fan 100 is less difficult, the axial space occupancy is more reasonable, the size of the fan 100 is smaller, and the appearance is more beautiful.

[0101] 8 and 9 , the ratio of the outer diameter D3 of the first grille ring 61 to the diameter D1 of the first blade 10 satisfies: 1≤D3 / D1≤1.1, and the ratio of the outer diameter D4 of the second grille ring 62 to the diameter D2 of the second blade 20 satisfies: 1≤D4 / D2≤1.1.

[0102] The first grille ring 61 is set corresponding to the external area, and the second grille ring 62 is set corresponding to the middle area, so that the first grille ring 61 can guide the airflow emitted from the external area, so that the divergent airflow is further emitted outward, thereby improving the wind dispersion effect. The first grille ring 61 can guide the airflow emitted from the middle area, so that the concentrated airflow is further gathered inward, thereby improving the wind gathering effect.

[0103] The outer diameter of the first grille ring 61 is slightly larger than or equal to the diameter of the first fan blade 10, and the second grille ring 62 is slightly larger than or equal to the diameter of the second fan blade 20. On the one hand, the air guiding effect of the first grille ring 61 and the second grille ring 62 can be ensured. On the other hand, the outer dimensions of the air outlet grille 60 can be avoided from being too large, so that the internal components of the fan 100 are arranged more compactly and the space occupancy is more reasonable.

[0104] As shown in FIG10 , further, the angles formed between the multiple first guide grilles 611 in the first grille ring 61 and the axis are 5° to 90° (including the endpoint values), and the angles formed between the multiple second guide grilles 621 in the second grille ring 62 and the axis are 0° to 5° (including the endpoint values).

[0105] The axis refers to the rotation axis. The first grille ring 61 is provided with a plurality of first guide grilles 611 arranged along the circumferential direction, and the second grille ring 62 is provided with a plurality of second guide grilles 621 arranged along the circumferential direction. The first guide grilles 611 and the second guide grilles 621 can be generally arc-shaped and both have an angle with the axis.

[0106] The angle between the first guide grille 611 and the axis is the angle α in Figure 10, and the angle between the first guide grille 611 and the axis can be any value between 5° and 90° (such as: 5°, 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, etc.), and the angle between the second guide grille 621 and the axis can be 0°, 1°, 2°, 3°, 4°, 5°, etc., and the first guide grille 611 is inclined outward, and the second guide grille 621 is inclined inward.

[0107] As a result, the inclination angles of the first guide grille 611 and the second guide grille 621 are more reasonable. The inclination angle of the first guide grille 611 is more reasonable, which can guide the divergent airflow outward and improve the wind dispersion effect. The angle of the second guide grille 621 is more reasonable, which can guide the convergent airflow inward and improve the wind gathering effect.

[0108] If the inclination angle of the first guide grille 611 is too large, the airflow will directly hit the outer edge of the air guide tube 50 or the air outlet mesh cover 60, and if the angle is too small, the guide effect will be poor; if the inclination angle of the second guide grille 621 is too large, the airflow will hit, resulting in a decrease in airflow velocity and increased turbulence, affecting the air gathering and outlet effect and reducing the user experience.

[0109] In the specific embodiment shown in Figure 10, further, the thickness of the windward side of the first guide grille 611 is W1, and the sum of the thickness of the grille on the windward side of the first guide grille 611 is W2, and satisfies: 1.5mm≤W1≤5mm, 1.5mm≤W2≤5mm, and the width L2 of the first guide grille 611 satisfies: 4mm≤L2≤15mm.

[0110] The thickness of the windward side end and the windward side end of the grille plate of the first guide grille 611 is 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc. The specific shape of the grille plate is not limited, but the thickness of the windward side end and the windward side end needs to meet the above value range, and the thickness of the windward side and the windward side can be the same or different.

[0111] In this way, the thickness of the windward side end and the air outlet side end of the first guide grille 611 can be made more reasonable to ensure the structural strength and stability of the guide grille, and avoid the thickness of the first guide grille 611 being too low, which will cause shaking during the airflow diversion process, reduce the diversion effect and cause damage, and avoid the thickness of the first guide grille 611 being too large, which will increase wind resistance, reduce gas flow rate, and affect the air outlet effect.

[0112] The width of the first guide grille 611 can be 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm or 15mm, etc., which can avoid the width of the first guide grille 611 being too short, resulting in the guide path length being too short, and can also avoid the width of the first guide grille 611 being too long, resulting in the guide path length being too long, so as to ensure the guide effect, take into account the material cost of the first guide grille 611, and reduce the production cost of the fan 100.

[0113] The fan 100 also has an air inlet mesh cover 70, which is arranged at one axial end of the air guide tube 50, and an air outlet mesh cover 60 is arranged at the other axial end of the air guide tube 50 to prevent foreign matter from entering the fan 100 and improve the stability and reliability of the fan 100.

[0114] The inclination direction of the second guide grille 621 of the second grille ring 62 is opposite to the extension direction of the first blade 11 of the first fan blade 10 .

[0115] In the second embodiment, the inclination direction of the second guide grille 621 is opposite to the extension direction of the first blade 11, while in the scheme of the first fan blade 10 of the third embodiment, the inclination direction of the second guide grille 621 is opposite to the extension direction of the first sub-blade 1111 and the second sub-blade 1121.

[0116] The inclination direction of the grille blade shape of the second guide grille 621 is opposite to the inclination direction of the first blade 11 of the first fan blade 10. Relative to the rotation direction of the first fan blade 10, the leading edge (inlet side) of the first blade 11 is located at a forward position in the rotation direction, and the trailing edge (outlet side) of the blade is located behind the leading edge of the blade, that is, the blade shape is inclined in the rotation direction. The leading edge of the second guide grille 621 is located at a rearward position in the rotation direction of the first fan blade 10 and behind the trailing edge of the grille, so that the second guide grille 621 can guide the airflow generated by the first fan blade 10 toward the rotation axis. By making the inclination direction of the second guide grille 621 opposite to that of the first blade 11, the airflow generated by the first fan blade 10 can be specifically guided, which can effectively improve the wind gathering effect.

[0117] As shown in FIG. 1 to FIG. 4 , in the first embodiment, the fan 100 includes a first fan blade 10 , a second fan blade 20 , a first motor 30 , a second motor 40 , an air outlet mesh cover 60 , an air inlet mesh cover 70 , and an air guide tube 50 .

[0118] The first motor 30 is connected to the first fan blade 10, the second motor 40 is connected to the second fan blade 20, the first motor 30 is arranged in the first mounting portion 51 of the air guide tube 50, the second motor 40 is arranged in the second mounting portion 52 of the air guide tube 50, the air outlet mesh cover 60 is covered at one end of the air guide tube 50, and the air inlet mesh cover 70 is covered at the other end of the air guide tube 50.

[0119] The diameter of the first blade 10 is greater than the diameter of the second blade 20, and the air outlet grille 60 is constructed as a grille structure having a conventional grille.

[0120] In the first embodiment, by setting the first fan blade 10 and the second fan blade 20 with different diameters, and through the reverse rotation and speed difference of the first fan blade 10 and the second fan blade 20, a wind gathering mode and a wind dispersion mode are realized, thereby enriching the air outlet mode of the fan 100 and providing a user experience of the fan 100.

[0121] As shown in FIG. 5 to FIG. 11 , in the second embodiment, the fan 100 includes a first fan blade 10 , a second fan blade 20 , a first motor 30 , a second motor 40 , an air outlet mesh cover 60 , an air inlet mesh cover 70 , and an air guide tube 50 .

[0122] Among them, the first motor 30 is connected to the first fan blade 10, the second motor 40 is connected to the second fan blade 20, the first motor 30 is arranged in the first mounting part 51 of the air guide tube 50, the second motor 40 is arranged in the second mounting part 52 of the air guide tube 50, the air outlet mesh cover 60 is covered at one end of the air guide tube 50, and the air inlet mesh cover 70 is covered at the other end of the air guide tube 50.

[0123] The diameter of the first fan blade 10 is greater than the diameter of the second fan blade 20, and the air outlet grille 60 is constructed to have a first grille ring 61 and a second grille ring 62. The first grille ring 61 is used to guide wind away from the rotation axis, and the second grille ring 62 is used to guide wind toward the rotation axis.

[0124] In the second embodiment, by setting the first fan blade 10 and the second fan blade 20 with different diameters, and through the reverse rotation and speed difference of the first fan blade 10 and the second fan blade 20, the first grille ring 61 and the second grille ring 62 are cooperated to realize the wind gathering mode and the wind dispersion mode, enriching the air outlet mode of the fan 100 and providing the user experience of the fan 100.

[0125] As shown in FIG. 12 and FIG. 13 , in the third embodiment, the fan 100 includes a first fan blade 10 , a second fan blade 20 , a first motor 30 , a second motor 40 , an air outlet mesh cover 60 , an air inlet mesh cover 70 , and an air guide tube 50 .

[0126] The first motor 30 is connected to the first fan blade 10, the second motor 40 is connected to the second fan blade 20, the first motor 30 is arranged in the first mounting portion 51 of the air guide tube 50, the second motor 40 is arranged in the second mounting portion 52 of the air guide tube 50, the air outlet mesh cover 60 is covered at one end of the air guide tube 50, and the air inlet mesh cover 70 is covered at the other end of the air guide tube 50.

[0127] The diameter of the first fan blade 10 is greater than the diameter of the second fan blade 20, and the air outlet mesh cover 60 is constructed as a conventional mesh cover with an ordinary grille. The first blade 11 includes a first blade area 111 and a second blade area 112. The second blade area 112 coincides with the axial projection of the second fan blade 20, and the first blade area 111 is located outside the axial projection range of the second fan blade 20.

[0128] In the third embodiment, by setting the first fan blade 10 and the second fan blade 20 with different diameters, and through the reverse rotation and speed difference of the first fan blade 10 and the second fan blade 20, combined with the auxiliary air supply of the second blade area 112, the wind gathering mode and the wind dispersion mode are realized, the air outlet mode of the fan 100 is enriched, and the user experience of the fan 100 is provided.

[0129] The fan 100 adopts a first fan blade 10 and a second fan blade 20. The first fan blade 10 has a first blade area 111 and a second blade area 112, and the diameter of the first fan blade 10 is larger than the diameter of the second fan blade 20. At the same time, an air outlet mesh cover 60 with a first grille ring 61 and a second grille ring 62 is provided to achieve better wind gathering and dispersing effects.

[0130] Other structures and operations of the fan 100 according to the embodiment of the present application are well known to those skilled in the art and will not be described in detail here.

[0131] As shown in FIG18 , according to the control method of the fan 100 according to the embodiment of the present application, the control method includes:

[0132] Obtaining the air outlet mode of the fan 100, where the air outlet mode includes a dispersed air mode and a concentrated air mode;

[0133] According to the air outlet mode, the rotational speeds of the first fan blade 10 and the second fan blade 20 are adjusted so that there is a rotational speed difference between the first fan blade 10 and the second fan blade 20 .

[0134] The air outlet mode may include at least a scattered wind mode and a gathered wind mode, and may also include a large air volume mode, etc. For example, in the large air volume mode, both the first blade 10 and the second blade 20 can output air at a high speed, and when the fan 100 switches to the scattered wind mode or the gathered wind mode, the speed of the first blade 10 and the second blade 20 is adjusted to create a speed difference between the first blade 10 and the second blade 20, and through the speed difference, the gathered wind mode and the scattered wind mode are realized, thereby enriching the air outlet mode of the fan 100 and improving the user experience of the fan 100.

[0135] Adjusting the rotation speeds of the first fan blade 10 and the second fan blade 20 according to the air outlet mode specifically includes:

[0136] In the wind dispersion mode, the rotation speed of the first blade 10 is lower than the rotation speed of the second blade 20;

[0137] In the wind gathering mode, the rotation speed of the second blade 20 is lower than the rotation speed of the first blade 10 .

[0138] In the wind gathering mode, the rotation speed of the second fan blade 20 is higher than that of the first fan blade 10. After the airflow is initially accelerated by the first blade 11, it flows into the second fan blade 20. The second fan blade 20 further accelerates the airflow, which can effectively increase the airflow speed and further reduce the air outlet area to improve the wind gathering effect.

[0139] In the scattered wind mode, the rotation speed of the first fan blade 10 is higher than the rotation speed of the second fan blade 20. After the airflow is accelerated by the first blade 11, most of the airflow generated by the first blade 11 directly enters the external area, and the second fan blade 20 rotates further to generate supplementary airflow to supplement the airflow in the internal area, so that the air outlet in the scattered wind mode is more uniform. Both the external area and the internal area have scattered wind airflow with a slower gas flow rate, which effectively reduces the airflow speed to improve the scattered wind effect.

[0140] Both the scattered wind mode and the concentrated wind mode have multiple gears, and the control method also includes:

[0141] In the wind dispersion mode, the speed difference between the first fan blade 10 and the second fan blade 20 is 100 r / min to 250 r / min;

[0142] In the wind gathering mode, the speed difference between the first blade 10 and the second blade 20 is 500 r / min to 800 r / min, and is positively correlated with the gear position.

[0143] In the wind gathering mode, the speed of the first fan blade 10 is low, and the speed difference is within the range of 100r / min to 250r / min. In the wind dispersion mode, the speed of the first fan blade 10 is high, and the speed difference is within the range of 500r / min to 800r / min, so as to achieve better wind gathering effect and better wind dispersion effect.

[0144] The positive correlation between the speed difference and the gear means that there can be multiple gears in the wind dispersion mode, such as the first gear to the fifth gear. In the first gear to the fifth gear, the speeds of the first fan blade 10 and the second fan blade 20 increase or decrease in an equal increment. Correspondingly, the speed difference increases or decreases in an equal increment within the range of 100r / min to 250r / min. For example, in the first gear, the speed difference is 100r / min, and in the sixth gear, the speed difference is 250r / min; there can also be multiple gears in the wind gathering mode, such as the first gear to the fifth gear. In the first gear to the fifth gear, the speeds of the first fan blade 10 and the second fan blade 20 increase or decrease in an equal increment. Correspondingly, the speed difference increases or decreases in an equal increment within the range of 500r / min to 800r / min. For example, in the first gear, the speed difference is 500r / min, and in the sixth gear, the speed difference is 800r / min.

[0145] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0146] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A fan, characterized in that: include: a first fan blade, wherein the first fan blade has a first blade; The second fan blade, the first fan blade is coaxially arranged with the second fan blade, the first fan blade is located in front of the second fan blade, the first fan blade and the second fan blade have opposite rotation directions, the second fan blade has a second blade, the diameter D1 of the first fan blade is greater than the diameter D2 of the second fan blade, and the trailing edge of the first blade and the leading edge of the second blade are axially adjacent to each other.

2. A fan, characterized in that: include: a first fan blade, wherein the first fan blade has a first blade; The second fan blade, the first fan blade and the second fan blade are coaxially arranged, the first fan blade is located in front of the second fan blade, the second fan blade has a second blade, the diameter D1 of the first fan blade is greater than the diameter D2 of the second fan blade, and the trailing edge of the first blade and the leading edge of the second blade are axially adjacent to each other.

3. The fan according to claim 1 or 2, characterized in that: The diameter D1 of the first blade and the diameter D2 of the second blade satisfy: 0.4≤D2 / D1≤0.

9.

4. The fan according to claim 1 or 2, characterized in that: An extending direction from the leading edge of the first blade to the trailing edge of the blade is opposite to an extending direction from the leading edge of the second blade to the trailing edge of the blade.

5. The fan according to claim 1 or 2, characterized in that: A distance L1 between a blade trailing edge of the first blade and a blade leading edge of the second blade satisfies: 0<L1<80 mm.

6. The fan according to claim 1 or 2, characterized in that: Also includes: A power source is used to drive the first fan blade and the second fan blade to rotate.

7. The fan according to claim 6, characterized in that: The power source includes: a first motor and a second motor, the first motor is connected to the first fan blade by power, the second motor is connected to the second fan blade by power, and is suitable for controlling the rotation speed of the first fan blade and the second fan blade respectively.

8. The fan according to claim 7, characterized in that: Also includes: An air guide tube is provided with a first mounting portion and a second mounting portion, wherein the first mounting portion is used for mounting the first motor, and the second mounting portion is used for mounting the second motor.

9. The fan according to claim 8, characterized in that Also includes: An air outlet mesh cover is arranged on the air outlet side of the first fan blade and has a first grille ring and a second grille ring arranged in sequence in the radial direction, the first grille ring is used to diverge airflow away from the rotation axis, and the second grille ring is used to gather airflow toward the rotation axis.

10. The fan according to claim 9, characterized in that The ratio of the outer diameter D3 of the first grille ring to the diameter D1 of the first blade satisfies: 1≤D3 / D1≤1.1, and the ratio of the outer diameter D4 of the second grille ring to the diameter D2 of the second blade satisfies: 1≤D4 / D2≤1.

1.

11. The fan according to claim 9, characterized in that The angles formed between the plurality of first guide grilles in the first grille ring and the axis are 5° to 90°, and the angles formed between the plurality of second guide grilles in the second grille ring and the axis are 0° to 5°.

12. The fan according to claim 11, characterized in that The thickness of the first guide grille on the windward side is W1, and the thickness of the first guide grille on the windward side is W2, and the following conditions are satisfied: 1.5 mm ≤ W1 ≤ 5 mm, 1.5 mm ≤ W2 ≤ 5 mm.

13. The fan according to claim 11, characterized in that The width L2 of the first guide grille satisfies: 4mm≤L2≤15mm.

14. A method for controlling a fan, the method being suitable for controlling the fan according to any one of claims 1 to 13, characterized in that: include: Obtaining an air outlet mode of the fan, wherein the air outlet mode includes a scattered air mode and a concentrated air mode; According to the air outlet mode, the rotation speeds of the first fan blade and the second fan blade are adjusted so that there is a rotation speed difference between the first fan blade and the second fan blade.

15. The fan control method according to claim 14, characterized in that: The adjusting the rotation speeds of the first fan blade and the second fan blade according to the air outlet mode specifically includes: In the wind dispersion mode, the rotation speed of the first blade is lower than the rotation speed of the second blade; In the wind gathering mode, the rotation speed of the second fan blade is lower than the rotation speed of the first fan blade.

16. The fan control method according to claim 15, characterized in that: The wind dispersion mode and the wind gathering mode both have multiple gears, and the control method further includes: In the wind dispersion mode, the speed difference between the first fan blade and the second fan blade is 100 r / min to 250 r / min; In the wind gathering mode, the speed difference between the first fan blade and the second fan blade is 500r / min to 800r / min, and is positively correlated with the gear position.

Images