Efficient outer rotor fan

Abstract

The utility model relates to the technical field of fans, and discloses an efficient outer rotor fan which comprises an impeller module, a support module and a motor module, the motor module is detachably installed in the support module, the impeller module is fixedly connected to the motor module, the impeller module comprises a fan blade hub and blades, and the fan blade hub is fixedly connected to the support module. According to the utility model, disordered airflow is effectively cut and scattered through the tail edges of the blades of the impeller, so that the airflow separation phenomenon is reduced, the resistance generated by airflow separation is also reduced, meanwhile, the energy of small-scale vortexes is relatively low, the interference between the small-scale vortexes is relatively small, and the energy of the small-scale vortexes is relatively low. And then, the guide vane further guides the airflow subjected to primary treatment by sawteeth at the tail edge of the vane, and the disordered airflow with a certain rotational component is combed into regular axial flow, so that the airflow is discharged from the fan more orderly.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, specifically to a high-efficiency external rotor fan. Background Technology

[0002] A fan is a general-purpose mechanical device that converts mechanical energy into gas energy and enables the directional transport of gas. It is widely used in various fields such as industry, construction, agriculture, transportation, and energy. Based on their working principle, fans can be classified into positive displacement, turbine, and jet types; according to their application, they can be classified into industrial boiler fans, tunnel fans, and general exhaust fans; and according to the airflow direction, they can be classified into centrifugal fans, axial flow fans, and mixed flow fans. In the industrial field, fans are used for ventilation, dust removal, and cooling.

[0003] The impeller blades propel the airflow. At the trailing edge of the blades, the airflow forms complex vortex and turbulence structures. The interaction between the vortex and turbulence structures can cause the wind force to cancel each other out, thus greatly reducing the fan's flow rate and efficiency. Both vortex and turbulence generate rotating airflow, preventing the airflow from moving axially and causing severe airflow dispersion, which in turn affects the overall performance of the fan. Utility Model Content

[0004] To address the aforementioned problems in the existing technology, this utility model provides a high-efficiency external rotor fan that integrates airflow and avoids dispersion.

[0005] To achieve the aforementioned goal of integrating airflow and avoiding dispersion, this utility model provides the following technical solution: it includes an impeller module, a support module, and a motor module, wherein the motor module is detachably installed inside the support module, and the impeller module is fixedly connected to the motor module;

[0006] The impeller module includes a fan blade hub and blades. The fan blade hub is mounted on the motor module, and a plurality of trailing edges are provided on one side of the blades.

[0007] The support module includes a guide ring, a guide vane hub, and a rear guide vane. Several rear guide vanes are provided, all circumferentially and evenly distributed on the outer periphery of the guide vane hub, and the rear guide vanes are distributed in a clockwise oblique direction.

[0008] Preferably, at least two blades are provided, which are circumferentially distributed on the outer periphery of the fan blade hub. The blades are curved, and the blades gradually increase in size from the inside to the outside. The outer edge of the blades is flanged.

[0009] Preferably, a plurality of strip grooves are provided on one side of the curved surface of the blade, and the trailing edge of the blade is a serrated tail.

[0010] Preferably, the inner rings on both sides of the air guide ring have an air inlet cut and a diffuser, respectively, wherein the air inlet cut is an arc-shaped surface and the diffuser is an inclined surface, and the outer periphery of the air guide ring is also fixedly installed with reinforcing ribs.

[0011] Preferably, the guide vane hub is located at the center of the air guide ring, the guide vane hub is connected to the inner wall of the air guide ring through the rear guide vane, and the motor module is installed inside the guide vane hub.

[0012] Preferably, a diffuser rib is provided at the connection between the rear guide vane and the inner wall of the air guide ring. The angle between the diffuser rib and the inner wall of the air guide ring is 3-15°, and its height is 10-200mm.

[0013] Preferably, at least two heat dissipation holes are provided on the side end face of the guide vane hub, and a cavity is provided on the other side of the guide vane hub, with a number of damping strips provided inside the cavity.

[0014] Preferably, the motor module includes a motor rotor housing, a mounting flange, and a motor. The motor is detachably installed in the bracket module. The mounting flange and the motor rotor housing are used to install the impeller module, and all three rotate synchronously with the motor rotor housing.

[0015] Preferably, a mesh cover is also installed on the side wall of the air guide ring. The mesh cover has an annular mesh structure and multiple mounting pins on its outer periphery. The mesh cover is fixed to the air guide ring by the mounting pins, and the mesh gap of the mesh cover is 9.5mm.

[0016] Compared with the prior art, this utility model provides a high-efficiency external rotor fan, which has the following beneficial effects:

[0017] This high-efficiency external rotor fan effectively cuts and disperses turbulent airflow at the trailing edge of the impeller blades. This not only reduces airflow separation but also lowers the resistance caused by it. Simultaneously, the energy of small-scale eddies is relatively low, resulting in less interference between them and allowing for smoother airflow. The guide vanes further guide the airflow, which has undergone preliminary treatment by the serrated trailing edge of the blades, transforming the turbulent airflow with a certain rotational component into a more regular axial flow, allowing for more orderly airflow discharge from the fan. In this way, from the serrated trailing edge of the blades to the plastic guide vanes, the airflow gradually shifts from turbulent to stable and orderly, significantly improving the overall aerodynamic performance of the fan. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 This is a schematic diagram of the half-section structure of this utility model;

[0020] Figure 3 This is a schematic diagram of the impeller module of this utility model;

[0021] Figure 4 This is a schematic diagram of the support module of this utility model;

[0022] Figure 5 This is a schematic diagram of the impeller damping groove structure of this utility model;

[0023] Figure 6 This is a schematic diagram of the diffusion rib structure of this utility model;

[0024] Figure 7 This is a schematic diagram of the cross-sectional structure of the guide vanes of the air guide ring of this utility model with different diameters;

[0025] Figure 8 This is a schematic diagram of the notch structure of the air guide ring wire of this utility model;

[0026] Figure 9 This is a schematic diagram of the bottom reinforcement structure of the air guide ring of this utility model;

[0027] Figure 10 This is a schematic diagram of the cross-sectional structure of the blade at different diameters according to this utility model.

[0028] In the diagram: 10, air guide ring; 101, air inlet cut; 102, diffuser; 103, reinforcing rib; 20, fan impeller hub; 201, blade; 2011, strip groove; 2012, serrated tail; 30, guide vane hub; 301, rear guide vane; 3011, diffuser rib; 302, heat dissipation hole; 40, motor rotor housing; 41, mounting flange; 42, motor; 50, mesh cover. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] like Figure 1-4As shown, the fan includes an impeller module, a support module, and a motor module, as well as a wire mesh cover 50. The wire mesh cover 50 is mounted on the side wall of the air guide ring 10. The wire mesh cover 50 has a ring-shaped mesh structure with multiple mounting pins on its outer periphery. The wire mesh cover 50 is fixed to the air guide ring 10 by these pins. The mesh opening of the wire mesh cover 50 is 9.5mm. The cover is made of steel wire, which provides high strength and toughness, effectively preventing larger debris and foreign objects from entering the fan, protecting the motor and impeller from damage. It also prevents direct contact with the high-speed rotating impeller, avoiding injury. The 9.5mm mesh opening of the wire mesh cover prevents hands from passing through, meeting safety design standards. The motor module is detachably installed within the support module, and the impeller module is fixedly connected to the motor module. The fan consists of four main components: a motor, an impeller, a wire mesh cover, and an air guide ring. This modular design allows each component to be manufactured, tested, and replaced independently. During the production process, it facilitates specialized division of labor, improves production efficiency and product quality; during maintenance and repair, it enables quick location and replacement of faulty parts, reduces downtime, improves equipment availability, and lowers maintenance costs.

[0031] The motor module includes a motor rotor housing 40, a mounting flange 41, and a motor 42. The motor 42 is detachably mounted in the bracket module. The mounting flange 41 and the motor rotor housing 40 are used to mount the impeller module, and all three rotate synchronously with the motor rotor housing 40. Example 1

[0032] The impeller module includes a fan hub 20 and blades 201. The fan hub 20 is mounted on the motor module, and the blades 201 are fixedly mounted on the outer periphery of the fan hub 20. At least two blades 201 are provided, circumferentially distributed on the outer periphery of the fan hub 20. The blades 201 are curved, increasing in size from the inside to the outside, and have flanged outer edges. The curved blades 201 optimize the interaction between the blades and the airflow. During impeller rotation, the airflow adheres more smoothly to the blade surface, reducing airflow separation and turbulence, and improving the blades' work efficiency on the airflow.

[0033] like Figure 10 As shown, cylindrical curved surfaces with Φ200, Φ260, Φ320, Φ380, and Φ440 are constructed with the center of the central hole of the guide ring as the center. These surfaces intersect the impeller curved surface, and the intersection sections are shown in the figure. Figure 10 As shown, draw a line segment from the bottom to the top center of the cross section. Draw a ray to the right with the left end of the line segment as the endpoint. The angle between the ray and the line segment is Δ, where 10 degrees ≦ Δ ≦ 60 degrees. The length of the line segment is C, where 60 ≦ C ≦ 300 mm.

[0034] The impeller of this application has the following cross-sectional dimensions: Φ200 with a cross-sectional angle of Δ=23 degrees and C=83.1 mm; Φ260 with a cross-sectional angle of Δ=21 degrees and C=98.8 mm; Φ320 with a cross-sectional angle of Δ=20 degrees and C=119.4 mm; Φ380 with a cross-sectional angle of Δ=19 degrees and C=141.1 mm; and Φ440 with a cross-sectional angle of Δ=18 degrees and C=157.9 mm.

[0035] The blade design, with its progressively larger blades from the inside out, conforms to the diffusion pattern of airflow during rotation, resulting in more natural airflow and reduced energy loss. This design improves the ventilation efficiency of the fan by 15%-20% compared to traditional impellers. While meeting ventilation requirements, it effectively reduces energy consumption, achieving the dual goals of energy saving and high efficiency. The downward-curving outer edge of the blades effectively guides and constrains the airflow. It directs the airflow more concentratedly towards the fan outlet, reducing radial diffusion and improving exhaust efficiency and airflow directionality.

[0036] Several strip-shaped grooves 2011 are provided on one curved surface of the blade 201, and a serrated tail 2012 is also provided on one side of the blade 201. The single distribution trajectory extends from the outer side of the leading edge of the blade to the inner side of the trailing edge of the blade; for example Figure 5 As shown, the center-to-center spacing of the grooves is D, ranging from 5 to 30 mm; the spacing is F, ranging from 2 to 15 mm; and the width of the damping groove is E, ranging from 8 to 80 mm. D, E, and F are all constant values, and D = E + F. In the blade 201 of this application, the width of the damping groove is E = 7 mm, the spacing is F = 5 mm, the center-to-center spacing is D = 12 mm, and the depth is 1 mm.

[0037] The noise-reducing grooves on the back of the impeller and the serrated design of the blade trailing edge work together to significantly reduce the operating noise of the fan. The noise-reducing grooves disrupt the airflow on the back of the impeller, breaking the formation of large-scale vortices and reducing the noise generated when vortices detach. The serrated blade trailing edge cuts the airflow separated from the blade surface into smaller streams, dispersing the energy during airflow separation and further reducing noise.

[0038] The support module includes an air guide ring 10, a guide vane hub 30, and a rear guide vane 301. The guide vane hub 30 is located at the center of the air guide ring 10 and is connected to the inner wall of the air guide ring 10 via the rear guide vane 301. The motor module is installed inside the guide vane hub 30. The inner rings on both sides of the air guide ring 10 have an air inlet 101 and a diffuser 102, respectively. The air inlet 101 is an arc-shaped surface, and the diffuser 102 is a beveled surface. Reinforcing ribs 103 are also fixedly installed on the outer periphery of the air guide ring 10. The design of the air inlet 101 effectively reduces the length and width dimensions of the fan without affecting its ventilation performance, achieving a compact design. Figure 6As shown, the diffuser 102 has a cross-sectional diffusion angle of α, which ranges from 3° to 15°, and a diffuser height of H, where 10≦H≦200mm. In this application, α is 11° and the height is 50mm. The diffuser 102 is designed so that when the airflow enters the diffuser 102 after being accelerated by the impeller and the rear guide vanes, the airflow speed decreases as the cross-sectional area of ​​the diffuser 102 gradually increases. According to the principle of energy conversion, the kinetic energy of the airflow is converted into pressure energy, thereby increasing the static pressure of the fan and enabling the air to be transported to a greater distance.

[0039] Several rear guide vanes 301 are provided, all circumferentially and evenly distributed on the outer periphery of the guide vane hub 30. The rear guide vanes 301 are distributed obliquely in a clockwise direction. This arrangement of the rear guide vanes 301 precisely guides the airflow exiting the impeller, converting excess rotational components into axial flow, effectively reducing airflow turbulence and energy loss. Through carefully designed rear guide vane shape and angle, airflow can pass through more evenly and smoothly, improving the fan's static pressure and efficiency, and increasing the ventilation efficiency of the guide vane ring by 10%-15%.

[0040] like Figure 7 As shown, with the center of the middle hole of the air guide ring as the center, construct cylindrical curved surfaces with diameters of Φ200, Φ250, Φ300, Φ350, Φ400, and Φ450, which intersect with the rear guide vane of the air guide ring respectively. Draw a line segment from the bottom to the top center of the intersection section. Draw a ray to the right with the left end point of the line segment as the endpoint. The angle between the ray and the line segment is γ, 40≦γ≦80, and the length of the line segment is c, 15≦c≦80.

[0041] The air guide rings of this application have the following cross-sectional dimensions: at Φ200, γ=67 degrees, c=26.1mm; at Φ250, γ=62 degrees, c=26.4mm; at Φ300, γ=59 degrees, c=26.9mm; at Φ350, γ=57 degrees, c=26.4mm; at Φ400, γ=55 degrees, c=26.0mm; and at Φ450, γ=51 degrees, c=25.1mm.

[0042] A diffuser rib 3011 is also provided at the connection between the rear guide vane 301 and the inner wall of the air guide ring 10. The diffuser rib 3011 serves two purposes: firstly, it strengthens the connection between the rear guide vane and the side wall of the air guide ring, increasing its lifespan; secondly, it facilitates mold opening. If the air guide ring does not have this reinforcing structure, an additional core-pulling structure needs to be made in the mold, which will significantly increase the cost. Conversely, with this structure added, the mold does not need to design a core-pulling structure to form the structure, and only a conventional opening and closing structure is needed, which will significantly reduce the cost.

[0043] The air guide ring 10 also has a notch, and a wire is installed inside the notch, such as... Figure 8As shown, a notch is reserved in the side wall, with a width of a, 5≦a≦12, a depth of b, 5≦b≦100, and an angle of β, 10≦β≦80. The notch in this application has a=8, b=42, β=45, and extends to the left. The advantage of this structure is that it allows the motor lead with the connector installed to be directly installed onto the air guide ring. Compared to traditional pre-drilled holes, this notch avoids the traditional hole penetrating the fan and being too large, which weakens the diffuser's effect, causing leakage and air leakage at this location.

[0044] The bottom outer periphery of the air guide ring 10 is also provided with a reinforcing structure, which consists of multiple intersecting curves, such as... Figure 9 As shown, the curve change trajectory of the bottom reinforcement structure conforms to: the distance from the scanning section to the scanning trajectory SDn=A+B*sin(n*360*trajpar).

[0045] Where: A is the basic distance;

[0046] B represents the amplitude;

[0047] n is the cycle period;

[0048] trajpar refers to the value of the system variable, which can be between 0 and 1.

[0049] This application: SD1 = 0 + 21 * sin(trajpar * 360 * 1.5), SD1 = 0 - 21 * sin(trajpar * 360 * 1.5)

[0050] The bottom reinforcement structure improves the stability of the air guide ring during installation. During use, the air guide ring needs to withstand its own weight, vibrations from the fan, and the forces of airflow. The bottom reinforcement structure disperses these forces, preventing deformation or loosening of the air guide ring on the mounting surface and ensuring a tight fit with the foundation. This not only guarantees the safety of fan operation but also reduces noise and performance degradation caused by unstable installation, extending the service life of both the air guide ring and the fan, providing users with more reliable ventilation equipment.

[0051] At least two heat dissipation holes 302 are also provided on the side end face of the guide impeller hub 30. A cavity is provided on the other side of the guide impeller hub 30. Several shock-absorbing strips are provided inside the cavity, which can effectively dampen the motor when the motor is installed and extend the service life of the fan.

[0052] In this axial flow fan, the impeller rotates counterclockwise, while the guide vanes are distributed clockwise. During operation, the impeller blades propel the airflow, creating complex vortices and turbulent structures at the blade trailing edges. The unique shape of the serrated blade trailing edges effectively cuts and disperses these turbulent airflows. In this way, the originally concentrated large-scale vortices are broken down into many smaller vortices. This not only reduces airflow separation but also lowers the drag caused by airflow separation. Furthermore, the smaller vortices have relatively low energy and less interference with each other, allowing for a smoother airflow. The guide vanes further guide the airflow after its initial processing by the serrated blade trailing edges. They organize the airflow, which carries a certain residual rotational component and turbulence, into a more regular axial flow, allowing the airflow to exit the fan more orderly. Thus, from the serrated blade trailing edges to the plastic guide vanes, the airflow gradually shifts from turbulent to stable and orderly, significantly improving the overall aerodynamic performance of the fan. Example 2

[0053] The trailing edge of the blade 201 can also be semi-circular, with the thickness of the semi-circle gradually decreasing along its rotation direction. This trailing edge can guide the airflow, causing the airflow at multiple blades 201 to flow in a folded parallel manner. The number of guide vanes 301 is the same as that of the blades 201, so that the airflow can move axially in parallel through the guidance of the guide vanes, thus preventing the airflow from affecting each other.

[0054] Working principle: The motor 42 on the motor unit is installed inside the guide vane hub 30. The impeller is installed on the motor shaft of the motor 42 through the motor rotor housing 40 and the mounting flange 41. Then, the air inlet ring 202 on the impeller is fitted into the inner wall of the bracket 10. Then, the screen 50 is installed on the other side of the bracket 10. When the motor is started, the blades 201 rotate, which causes the airflow to flow. The airflow is drawn into the fan through the rotation of the blades 201. At this time, the airflow is in a rotating state. Then, the rotating airflow is rectified by the rear guide vane 301 and can be changed to horizontal flow.

[0055] In summary, this high-efficiency external rotor fan effectively cuts and disperses turbulent airflow at the trailing edge of the impeller blades. This not only reduces airflow separation but also lowers the resistance caused by it. Furthermore, the small-scale eddies have relatively low energy and minimal interference, allowing for smoother airflow. The guide vanes further guide the airflow, which has undergone preliminary treatment by the serrated trailing edge of the blades, transforming the turbulent airflow with a certain rotational component into a more regular axial flow, resulting in a more orderly exhaust from the fan. Thus, from the serrated trailing edge of the blades to the plastic guide vanes, the airflow gradually transitions from turbulent to stable and orderly, significantly improving the overall aerodynamic performance of the fan.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0057] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency external rotor fan, comprising an impeller module, a support module, and a motor module, characterized in that: The motor module is detachably installed inside the bracket module, and the impeller module is fixedly connected to the motor module; The impeller module includes a fan impeller hub (20) and blades (201). The fan impeller hub (20) is mounted on the motor module, and one side of the blades (201) is also provided with several trailing edges. The support module includes a guide ring (10), a guide vane hub (30) and a rear guide vane (301). Several rear guide vanes (301) are provided, all of which are evenly distributed circumferentially on the outer periphery of the guide vane hub (30), and the rear guide vanes (301) are distributed in a clockwise oblique direction.

2. The high-efficiency external rotor fan according to claim 1, characterized in that: At least two blades (201) are provided and are circumferentially distributed on the outer periphery of the fan blade hub (20). The blades (201) are curved and gradually increase in size from the inside to the outside. The outer edge of the blades (201) is flanged.

3. The high-efficiency external rotor fan according to claim 2, characterized in that: The blade (201) has several strip grooves (2011) on one side of its curved surface, and the trailing edge of the blade (201) is a serrated tail (2012).

4. The high-efficiency external rotor fan according to claim 1, characterized in that: The inner sides of the air guide ring (10) are respectively an air inlet cut (101) and a diffuser (102). The air inlet cut (101) is an arc-shaped surface, and the diffuser (102) is a sloping surface. The outer periphery of the air guide ring (10) is also fixedly installed with a reinforcing rib (103).

5. A high-efficiency external rotor fan according to claim 1, characterized in that: The guide vane hub (30) is located at the center of the air guide ring (10). The guide vane hub (30) is connected to the inner wall of the air guide ring (10) through the rear guide vane (301). The motor module is installed inside the guide vane hub (30).

6. A high-efficiency external rotor fan according to claim 1, characterized in that: A diffuser rib (3011) is also provided at the connection between the rear guide vane (301) and the inner wall of the air guide ring (10). The angle between the diffuser rib (3011) and the inner wall of the air guide ring (10) is 3-15° and its height is 10-200mm.

7. A high-efficiency external rotor fan according to claim 1, characterized in that: At least two heat dissipation holes (302) are also provided on the side end face of the guide vane hub (30), and a cavity is provided on the other side of the guide vane hub (30), with a number of damping strips provided inside the cavity.

8. A high-efficiency external rotor fan according to claim 1, characterized in that: The motor module includes a motor rotor housing (40), a mounting flange (41), and a motor (42). The motor (42) is detachably installed in the bracket module. The mounting flange (41) and the motor rotor housing (40) are used to install the impeller module, and the three rotate synchronously with the motor rotor housing (40).

9. A high-efficiency external rotor fan according to claim 1, characterized in that: A mesh cover (50) is also installed on the side wall of the air guide ring (10). The mesh cover (50) has an annular mesh structure and multiple mounting pins are provided on its outer periphery. The mesh cover (50) is fixed on the air guide ring (10) by the mounting pins. The mesh gap of the mesh cover (50) is 9.5mm.

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