Dual-rotor axial fan

Abstract

The present invention provides a dual-rotor axial flow fan, comprising an upper housing and a lower housing, wherein an upper shaft and a lower shaft are rotatably mounted in the axial fixing holes of the upper housing and the lower shaft via bearings. A rotor assembly is fixedly mounted on both adjacent ends of the upper shaft and the lower shaft, wherein an inner impeller is fixedly mounted on the rotor assembly fixed to the upper shaft. An outer impeller is fixedly mounted on the rotor assembly fixed to the lower shaft. The inner impeller and the outer impeller are arranged on the same plane, and the inner blades of the inner impeller are arranged between the outer blades of the outer impeller and the rotor assembly. A dynamic sealing structure is employed between the inner and outer impellers, as well as between the outer impeller and the housing, of the axial flow fan, which can effectively prevent gas backflow and greatly improve air supply efficiency. Furthermore, the inner and outer impellers of the axial flow fan can independently control their rotational speeds. By increasing the rotational speed of the inner impeller, the pressure difference between the shaft and the inner wall of the housing is reduced, thereby reducing gas backflow at the root of the inner impeller.

Description

Technical Field

[0001] The present invention relates to the technical field of axial flow fans, in particular to a dual-rotor axial flow fan. Background Art

[0002] Axial-flow fans are widely used in production and everyday life. To achieve a certain air volume, they need to increase their speed. However, when the speed reaches a certain level, air delivery efficiency decreases significantly. High speeds and manufacturing and installation errors can also cause fan blade vibration and noise. Vibration can also damage equipment, while noise can negatively impact the quality of life and production. Effectively reducing fan operating noise can help improve the noise environment in production and everyday life, enhancing the user experience.

[0003] Furthermore, existing axial-flow fans typically have a single impeller, and the speed at the impeller's root is much lower than at the blade tip. Consequently, the pressure at the blade tip is higher than at the blade root, causing airflow to leak through the root, reducing the fan's air delivery efficiency. Furthermore, pressure can easily bleed between the impeller and the frame, causing air to flow back, reducing air delivery efficiency.

[0004] Therefore, those skilled in the art are in urgent need of an axial flow fan with low vibration, high air supply efficiency, backflow prevention and multiple application scenarios. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a dual-rotor axial flow fan to solve the problems of large fan vibration, strong noise, weak air supply capacity and easy gas backflow in the prior art.

[0006] The present invention provides a dual-rotor axial flow fan, which includes: an upper shell and a lower shell, wherein the upper shell is coaxially fixed to the lower shell; an upper rotating shaft is rotatably provided in the axial center fixing hole of the upper shell via a bearing, and a lower rotating shaft is rotatably provided in the axial center fixing hole of the lower shell via a bearing; a rotor assembly is fixedly provided at both ends adjacent to the upper rotating shaft and the lower rotating shaft, and a stator assembly is fixedly provided at the axial center of the upper shell and the axial center of the lower shell, and the rotor assembly acts with the stator assembly to drive the rotor assembly to rotate; an inner impeller is fixedly provided on the rotor assembly fixed on the upper rotating shaft, for supplying air near the axial center in the axial flow fan housing; an outer impeller is fixedly provided on the rotor assembly fixed on the lower rotating shaft, for supplying air away from the axial center in the axial flow fan housing; the inner impeller and the outer impeller are arranged on the same plane, and the inner wheel blades of the inner impeller are arranged between the outer wheel blades of the outer impeller and the rotor assembly.

[0007] Furthermore, the outer impeller also includes an outer wheel hub, an outer wheel rim, and a hub outer ring, wherein the outer wheel hub is fixedly set on the rotor assembly located on the lower rotating shaft, and the outer wheel hub circumference is evenly provided with guide ribs or straightening ribs radially outward for fixedly connecting the hub outer ring; the blade roots of the outer wheel blades are fixedly set on the hub outer ring, and the blade tips of the outer wheel blades are fixedly connected to the outer wheel rim.

[0008] Furthermore, the upper and lower sides of the outer wheel rim are fixedly provided with end sealing rings, and the inner walls of the upper shell and the lower shell are provided with annular grooves, and the end sealing rings extend into the annular grooves to form a dynamic sealing structure.

[0009] Furthermore, the inner impeller also includes an inner wheel hub and an inner wheel rim, wherein the inner wheel hub is fixedly set on the rotor assembly located on the upper rotating shaft, the blade root of the inner wheel fan blade is fixedly set on the inner wheel hub, and the blade tip of the inner wheel fan blade is fixedly connected to the inner wheel rim.

[0010] Furthermore, an intermediate sealing ring is provided on the upper side of the inner wheel rim, the cross section of the intermediate sealing ring is an inverted U-shape, and the upper side edge of the hub outer ring extends into the intermediate sealing ring to form a dynamic sealing structure.

[0011] In an embodiment of the present invention, at least two bearings are provided on the upper rotating shaft, and an elastic member is provided between the bearing provided at the lower end of the upper rotating shaft and the adjacent bearing, for making the upper rotating shaft, the bearing provided at the lower end of the upper rotating shaft and the rotor assembly float up and down; at least two bearings are provided on the lower rotating shaft, and an elastic member is provided between the bearing provided at the upper end of the lower rotating shaft and the adjacent bearing, for making the lower rotating shaft, the bearing provided at the upper end of the lower rotating shaft and the rotor assembly float up and down.

[0012] In an embodiment of the present invention, shaft sleeves are provided in the axial fixing holes of the upper shell and the lower shell, and the bearings are provided in the shaft sleeves.

[0013] In an embodiment of the present invention, the upper shell and the lower shell are fixedly connected via a flexible fixing member.

[0014] Furthermore, the flexible fixing member includes: an upper flexible seat, a lower flexible seat and a connecting rod, wherein the upper flexible seat and the lower flexible seat have a through hole in the center, the connecting rod passes through the through hole, and the two ends of the connecting rod extend radially outward, and the diameter of the extension part is larger than the diameter of the through hole, which is used to prevent the upper flexible seat and the lower flexible seat from falling off the connecting rod; the side walls of the upper flexible seat and the lower flexible seat both have an annular fixing groove, the snap ring on the upper shell is clamped in the annular fixing groove on the upper flexible seat, and the snap ring on the lower shell is clamped in the annular fixing groove on the lower flexible seat.

[0015] The present invention provides a dual-rotor axial flow fan, which includes: an upper shell and a lower shell, wherein the upper shell and the lower shell are coaxially fixed; the rotating shaft passes through the axial center fixing hole of the upper shell and the axial center fixing hole of the lower shell, and is fixedly connected to the upper shell and the lower shell; the upper and lower parts of the rotating shaft are fixedly provided with two bearings, and the bearings on the upper part of the rotating shaft and the bearings on the lower part of the rotating shaft are both sleeved with shaft sleeves, and a rotor assembly is fixedly provided on the outside of the shaft sleeve for rotating in coordination with a stator assembly fixedly provided on the outside of the axial center fixing hole of the upper shell or the lower shell; an inner impeller is fixedly provided on the rotor assembly on the upper part of the rotating shaft for supplying air near the axis center in the axial flow fan housing; an outer impeller is fixedly provided on the rotor assembly on the lower part of the rotating shaft for supplying air away from the axis center in the axial flow fan housing; the inner impeller and the outer impeller are arranged on the same plane, and the inner wheel blades of the inner impeller are arranged between the outer wheel blades of the outer impeller and the rotor assembly.

[0016] Furthermore, the outer impeller also includes an outer wheel hub, an outer wheel rim, and a hub outer ring, wherein the outer wheel hub is fixedly arranged on the rotor assembly located at the lower part of the rotating shaft, and the circumference of the outer wheel hub is evenly provided with guide ribs or straightening ribs radially outward for fixedly connecting the hub outer ring; the blade roots of the outer wheel blades are fixedly arranged on the hub outer ring, and the blade tips of the outer wheel blades are fixedly connected to the outer wheel rim.

[0017] Furthermore, the upper and lower sides of the outer wheel rim are fixedly provided with end sealing rings, and the inner walls of the upper shell and the lower shell are provided with annular grooves, and the end sealing rings extend into the annular grooves to form a dynamic sealing structure.

[0018] Furthermore, the inner impeller also includes an inner wheel hub and an inner wheel rim, wherein the inner wheel hub is fixedly arranged on the rotor assembly located on the upper part of the rotating shaft, the blade roots of the inner wheel blades are fixedly arranged on the inner wheel hub, and the blade tips of the inner wheel blades are fixedly connected to the inner wheel rim.

[0019] Furthermore, an intermediate sealing ring is provided on the upper side of the inner wheel rim, the cross section of the intermediate sealing ring is an inverted U-shape, and the upper side edge of the hub outer ring extends into the intermediate sealing ring to form a dynamic sealing structure.

[0020] In the embodiment of the present invention, the upper shell and the lower shell are fixedly connected by a flexible fixing member.

[0021] As can be seen from the above embodiments, the dual-rotor axial fan provided by the present invention has the following benefits: The axial fan utilizes dynamic seals between the inner and outer impellers, and between the outer impeller and the housing, effectively preventing gas backflow during high-speed rotation, significantly improving air delivery efficiency. The inner and outer impellers of the axial fan can each be independently controlled in rotation speed. By increasing the speed of the inner impeller, the pressure difference between the rotating shaft and the inner wall of the housing is reduced, further reducing gas backflow at the inner impeller blade root and improving air delivery efficiency.

[0022] In addition, the inner impeller and the outer impeller are connected in a floating manner, which can adaptively adjust the state of the impeller according to different speeds and reduce the magnitude of vibration.

[0023] It should be understood that the foregoing general description and the following detailed description are merely exemplary and illustrative and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings are a part of the specification of the present invention and illustrate exemplary embodiments of the present invention. Together with the description, the drawings serve to explain the principles of the present invention.

[0025] Figure 1 This is a cross-sectional view of Example 1 of the dual-rotor axial flow fan provided by the present invention.

[0026] Figure 2 This is an exploded view of Example 1 of the dual-rotor axial flow fan provided by the present invention.

[0027] Figure 3 This is an exploded view of the second embodiment of the dual-rotor axial flow fan provided by the present invention.

[0028] Figure 4 This is an exploded view of Example 3 of the dual-rotor axial flow fan provided by the present invention.

[0029] Figure 5 This is an exploded view of the fourth embodiment of the dual-rotor axial flow fan provided by the present invention.

[0030] Figure 6 This is a cross-sectional view of Example 5 of the dual-rotor axial flow fan provided by the present invention.

[0031] Figure 7This is a structural diagram of a first embodiment of the housing connection method of a dual-rotor axial flow fan provided by the present invention.

[0032] Figure 8 This is a structural diagram of a second embodiment of the casing connection method of the dual-rotor axial flow fan provided by the present invention.

[0033] Figure 9 This is an exploded view of Example 1 of the circular housing of the dual-rotor axial flow fan provided by the present invention.

[0034] Figure 10 This is an exploded view of the second embodiment of the circular casing of the dual-rotor axial flow fan provided by the present invention.

[0035] Figure 11 Schematic diagram of the flexible connection of the circular shell of the dual-rotor axial flow fan provided by the present invention.

[0036] Figure 12 This is a cross-sectional view of Example 6 of the dual-rotor axial flow fan provided by the present invention.

[0037] Description of reference numerals:

[0038] 1-upper casing, 2-lower casing, 3-bearing, 4-upper rotating shaft, 5-lower rotating shaft, 6-rotor assembly, 7-stator assembly, 8-inner impeller, 9-outer impeller, 10-inner wheel blade, 11-inner wheel hub, 12-inner wheel rim, 13-outer wheel blade, 14-outer wheel hub, 15-outer wheel rim, 16-hub outer ring, 17-guide rib, 18-rectifier rib, 19-end sealing ring, 20-annular groove, 21-middle sealing ring, 22-elastic part, 23-sleeve, 24-flexible fixing part, 25-upper flexible seat, 26-lower flexible seat, 27-connecting rod, 28-rotating shaft, 29-bearing limiting ring, 30-limiting shaft sleeve, 31-fixing flange, 32-elastic nipple, 33-clamping ring, 34-base plate. DETAILED DESCRIPTION

[0039] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0040] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the present invention. The present description and examples are intended to be illustrative only.

[0041] The present invention provides a dual-rotor axial flow fan. In a specific embodiment, Figure 1As shown, the axial flow fan comprises an upper shell 1 and a lower shell 2, wherein the upper shell 1 and the lower shell 2 are coaxially fixed. The upper shell 1 and the lower shell 2 can be square structures, or as shown in FIG. Figure 9 In addition, the upper vent of the upper shell 1 and the lower vent of the lower shell 2 are provided with guide ribs 17 or rectifying ribs 18. Specifically, the guide ribs 17 are provided at the air inlet and the rectifying ribs 18 are provided at the air outlet.

[0042] In a specific embodiment, Figure 1 As shown, an upper shaft 4 is rotatably mounted within the axial fixing hole of the upper housing 1 via a bearing 3. A lower shaft 5 is rotatably mounted within the axial fixing hole of the lower housing 2 via a bearing 3. The upper shaft 4 and lower shaft 5 do not contact each other. Furthermore, a sleeve 23 is mounted within the axial fixing holes of both the upper and lower housings 1 and 2, with the bearing 3 mounted within the sleeve 23. Specifically, the sleeve 23 is positioned between the bearing and the axial fixing hole.

[0043] The rotor assembly 6 is fixedly provided at both ends adjacent to the upper rotating shaft 4 and the lower rotating shaft 5, and the rotor assembly 6 is fixed to the upper rotating shaft 4 and the lower rotating shaft 5 through a fixing flange 31. The stator assembly 7 is fixedly provided at the axis center of the upper shell 1 and the axis center of the lower shell 2. Specifically, the stator assembly 7 is fixedly provided on the shaft sleeve 23. The rotor assembly 6 and the stator assembly 7 act to drive the rotor assembly 6 to rotate. In this embodiment, the fixing flange 31 can limit the position of the bearing 3 close to the fixing flange 31, and the position of other bearings 3 is limited by the retaining spring provided on the upper rotating shaft 4. In addition, the outer side of the outer ring of the bearing of the bearing 3 located at the upper end of the upper rotating shaft 4 and the lower end of the lower rotating shaft 5 is limited by the main city limiting ring 29 provided on the shaft sleeve 23, and the outer side of the inner ring of the bearing is limited by the retaining spring.

[0044] In addition, in the embodiment of the present invention, the rotor assembly 6 located at the upper shaft 4 and the rotor assembly 6 located at the lower shaft 5 can rotate in the same direction or in opposite directions. Figure 2 As shown, the upper shaft 5 and the lower shaft 6 rotate in the same direction. Figure 5 As shown, the upper rotating shaft 5 and the lower rotating shaft 6 rotate in opposite directions, and the two rotating shafts realize forward rotation and reverse rotation respectively, that is, the two motors realize forward and reverse rotation respectively, which can reduce the turbulent vibration phenomenon.

[0045] An inner impeller 8 is fixedly mounted on the rotor assembly 6 fixed to the upper rotating shaft 4, and is used to supply air near the axis of the axial fan housing. An outer impeller 9 is fixedly mounted on the rotor assembly 6 fixed to the lower rotating shaft 5, and is used to supply air away from the axis of the axial fan housing. The inner impeller 8 and the outer impeller 9 are arranged on the same plane, and the inner impeller blades 10 of the inner impeller 8 are arranged between the outer impeller blades 13 of the outer impeller 9 and the rotor assembly 6. In addition, the space between the outer impeller blades 13 of the outer impeller 9 and the rotor assembly 6 is hollowed out to supply air to the inner impeller 8. In the drawings of the present invention, the direction indicated by the arrow is the direction of airflow.

[0046] In a specific embodiment of the present invention, the outer impeller 9 further includes an outer wheel hub 14, an outer wheel rim 15, and a wheel hub outer ring 16. The outer wheel hub 14 is fixedly mounted on the rotor assembly 6 located on the lower rotating shaft 5, and the outer wheel hub 14 is evenly provided with guide ribs 17 or straightening ribs 18 radially outwardly on its circumference, for fixedly connecting the wheel hub outer ring 16. When the inner impeller 8 delivers air downward, the outer wheel hub 14 is evenly provided with straightening ribs 18 radially outwardly on its circumference; when the inner impeller 8 delivers air upward, the outer wheel hub 14 is evenly provided with guide ribs 17 radially outwardly on its circumference. The guide ribs 17 are used to guide the airflow and minimize airflow turbulence. The straightening ribs 18 are generally arranged in the air supply direction of the inner wheel blades 10 or the outer wheel blades 13 to adjust the direction of the airflow.

[0047] The blade roots of the outer impeller blades 13 are fixedly mounted on the outer ring 16 of the hub, and the blade tips of the outer impeller blades 13 are fixedly connected to the outer rim 15. Generally, the outer impeller blades 13, the outer hub 14, the outer rim 15, the hub outer ring 16, and the guide ribs 17 or the straightening ribs 18 are integrally formed, which helps to improve the structural strength of the outer impeller 9.

[0048] In addition, the upper and lower sides of the outer wheel rim 15 are fixedly provided with end sealing rings 19. The inner walls of the upper shell 1 and the lower shell 2 are provided with annular grooves 20. The end sealing rings 19 extend into the annular grooves 20 to form a dynamic sealing structure. The annular grooves 20 can extend radially or axially upward or downward to form a U-shaped cross-section. Figure 1 As shown, the annular groove 20 is on the inner wall of the upper shell 1 and the lower shell 2, and extends axially upward or downward. The longitudinal section of the annular groove 20 is a U-shaped section. The end sealing ring 19 extends into the interior of the annular groove 20 without contacting the annular groove 20, forming a dynamic sealing structure, which can reduce air leakage, ensure the air pressure difference inside and outside the axial flow fan housing, and improve the air outlet efficiency.

[0049] In a specific embodiment of the present invention, the inner impeller 8 further includes an inner hub 11 and an inner rim 12. The inner hub 11 is fixedly mounted on the rotor assembly 6 located on the upper shaft 4. The roots of the inner blades 10 are fixedly mounted on the inner hub 11, and the tips of the inner blades 10 are fixedly connected to the inner rim 12. The inner blades 10, inner hub 11, and inner rim 12 are integrally formed, which helps to enhance the structural strength of the inner impeller 8.

[0050] In addition, an intermediate sealing ring 21 is provided on the upper side of the inner wheel rim 12. The cross-section of the intermediate sealing ring 21 is an inverted U-shape. The upper side edge of the hub outer ring 16 extends into the intermediate sealing ring 21 without contacting the intermediate sealing ring 21, and is used to form a dynamic sealing structure, which can further reduce airflow leakage, ensure the air pressure difference inside and outside the axial fan casing, and improve the air outlet efficiency.

[0051] In the embodiment of the present invention, an inner impeller 8 and an outer impeller 9 are provided. By increasing the speed of the inner impeller 8, the pressure difference between the inner impeller 8 and the outer impeller 9 is balanced as much as possible to prevent air leakage from the inner impeller 8. When a single impeller is provided, the speed at the impeller blade root is much lower than the speed at the blade tip. At this time, the pressure at the blade tip is greater than the blade root, and air leakage through the blade root will occur, reducing the air supply efficiency of the fan blade.

[0052] like Figure 2 In the illustrated embodiment, the inner and outer blades 10, 13 are tilted in the same direction, and the upper and lower rotor assemblies 6 rotate in the same direction. Therefore, both the inner and outer impellers 8, 9 deliver air in the same direction. In this embodiment, both the inner and outer blades 10, 13 are tilted downward, and the rotor assemblies 6 rotate counterclockwise. Therefore, both the inner and outer impellers 8, 9 deliver air downward.

[0053] like Figure 3 In the illustrated embodiment, the inner and outer blades 10 and 13 are tilted in different directions, while the upper and lower rotor assemblies 6 rotate in the same direction. Consequently, the inner and outer impellers 8 and 9 deliver air in opposite directions. In this embodiment, the inner blades 10 are tilted upward, while the outer blades 13 are tilted downward. Both rotor assemblies 6 rotate counterclockwise, resulting in the inner impeller 8 delivering air upward and the outer impeller 9 delivering air downward.

[0054] like Figure 4 In the illustrated embodiment, the inner and outer blades 10 and 13 are tilted in different directions, while the upper and lower rotor assemblies 6 rotate in the same direction. Consequently, the inner and outer impellers 8 and 9 deliver air in opposite directions. In this embodiment, the inner blades 10 are tilted upward, while the outer blades 13 are tilted downward. Both rotor assemblies 6 rotate counterclockwise, resulting in the inner impeller 8 delivering air upward and the outer impeller 9 delivering air downward.

[0055] like Figure 5In the illustrated embodiment, the inner and outer blades 10, 13 are tilted in different directions—one tilted counterclockwise and the other tilted clockwise. Furthermore, the upper and lower rotor assemblies 6 rotate in different directions, resulting in the same air flow for the inner and outer impellers 8, 9. In this embodiment, both the inner and outer blades 10, 13 are tilted downward, with the inner blades 10 tilting counterclockwise and the outer blades 13 tilting clockwise. The rotor assemblies 6 rotate in opposite directions, resulting in both the inner and outer impellers 8, 9 delivering air downward.

[0056] like Figure 9 In the embodiment shown, the upper shell 1 and the lower shell 2 are circular, the inner wheel blades 10 and the outer wheel blades 13 have the same inclination direction, both inclined downward, and the upper and lower rotor assemblies 6 have the same rotation direction. At this time, the inner impeller 8 and the outer impeller 9 both supply air downward.

[0057] like Figure 10 In the embodiment shown, the upper shell 1 and the lower shell 2 are circular, the inner wheel blades 10 and the outer wheel blades 13 have the same inclination direction, both inclined upward, and the upper and lower rotor assemblies 6 have the same rotation direction. At this time, the inner impeller 8 and the outer impeller 9 both supply air upward.

[0058] In a specific embodiment of the present invention, at least two bearings 3 are disposed on the upper rotating shaft 4. An elastic member 22 is disposed between the bearing 3 disposed at the lower end of the upper rotating shaft 4 and its adjacent bearing 3 to enable a variable spacing between the two bearings, thereby driving the upper rotating shaft 4, the bearing 3 disposed at the lower end of the upper rotating shaft 4, and the rotor assembly 6 to float up and down, thereby driving the inner impeller 8 to float up and down, allowing the inner impeller 8 to adaptively adjust its vertical position according to the rotational speed, thereby reducing vibration. Preferably, the elastic member 22 is a spring, which is sleeved on the upper rotating shaft 4.

[0059] At least two bearings 3 are provided on the lower shaft 5. An elastic member 22 is provided between the bearing 3 at the upper end of the lower shaft 5 and its adjacent bearing 3. This member 22 is used to allow the lower shaft 5, the bearing 3 at the upper end of the lower shaft 5, and the rotor assembly 6 to float up and down, thereby driving the outer impeller 9 to float up and down. This allows the outer impeller 9 to adaptively adjust its vertical position according to the rotational speed, thereby reducing vibration. Preferably, the elastic member 22 is a spring, which is sleeved on the lower shaft 5.

[0060] like Figure 6In the illustrated embodiment, the inner wall of the sleeve 23 has a limiting convex ring. An elastic member 22 is disposed between the bearing 3 disposed at the upper end of the upper shaft 4 and the limiting convex ring. This member is used to adjust the spacing between the bearing 3 and the limiting convex ring, thereby allowing the upper shaft 4, the bearing 3 disposed at the lower end of the upper shaft 4, and the rotor assembly 6 to float up and down, thereby driving the inner impeller 8 to float up and down, allowing the inner impeller 8 to adaptively adjust its vertical position according to the rotational speed, thereby reducing vibration. Preferably, the elastic member 22 is a spring, which is sleeved on the upper shaft 4.

[0061] Similarly, an elastic member 22 is provided between the bearing 3 at the lower end of the lower shaft 5 and the limiting protrusion. This member is used to adjust the spacing between the bearing 3 and the limiting protrusion, thereby allowing the lower shaft 5, the bearing 3 at the upper end of the lower shaft 5, and the rotor assembly 6 to float up and down, thereby driving the outer impeller 9 to float up and down, allowing the outer impeller 9 to adaptively adjust its vertical position according to the rotational speed, thereby reducing vibration. Preferably, the elastic member 22 is a spring, which is sleeved on the lower shaft 5.

[0062] like Figure 7 In one embodiment shown, the upper shell 1 and the lower shell 2 are fixedly connected by fixing members such as bolts or screws.

[0063] like Figure 8 In another embodiment shown, the upper shell 1 and the lower shell 2 are fixedly connected by a flexible fixing member 24. Connecting the upper shell 1 and the lower shell 2 by the flexible fixing member 24 can reduce the transmission efficiency of vibration.

[0064] Specifically, the flexible fixing member 24 includes an upper flexible seat 25, a lower flexible seat 26, and a connecting rod 27. The upper flexible seat 25 and the lower flexible seat 26 have through holes in their centers, through which the connecting rod 27 passes. The ends of the connecting rod 27 extend radially outward, and the diameter of the extension portion is larger than the diameter of the through hole, to prevent the upper flexible seat 25 and the lower flexible seat 26 from falling off the connecting rod 27.

[0065] The side walls of the upper flexible seat 25 and the lower flexible seat 26 both have annular fixing grooves. The snap ring 33 on the upper shell 1 is snapped into the annular fixing groove on the upper flexible seat 25 , and the snap ring 33 on the lower shell 2 is snapped into the annular fixing groove on the lower flexible seat 26 .

[0066] The upper and lower surfaces, side walls and upper and lower surfaces of the upper and lower flexible seats 25 and the lower flexible seats 26 as well as the annular fixing grooves are provided with elastic nipples 32 . The elastic nipples 32 are used to reduce the contact area and thus reduce the vibration transmission.

[0067] like Figure 11In the embodiment shown, the side wall of the upper flexible support 25 of the flexible fixing member 24 is clamped to the clamping ring 33 of the upper shell 1, and the side wall of the lower flexible support 26 of the flexible fixing member 24 is clamped to the clamping ring 33 on the lower shell 2. The connecting rod 27 passes through the central through holes of the upper flexible seat 25, the lower flexible seat 26 and the connecting hole of the bottom plate 34, and is tightened at both ends of the connecting rod 27 by screws and other fixing members, so that the upper shell 1, the lower shell 2 and the bottom plate 34 are flexibly connected together.

[0068] like Figure 12 FIG2 shows an embodiment of a dual-rotor axial flow fan provided by the present invention. In the embodiment shown in the figure, the axial flow fan comprises: an upper shell 1 and a lower shell 2, wherein the upper shell 1 and the lower shell 2 are coaxially fixedly arranged. The upper shell 1 and the lower shell 2 can be square structures, or as shown in FIG2. Figure 9 In addition, the upper vent of the upper shell 1 and the lower vent of the lower shell 2 are provided with guide ribs 17 or rectifying ribs 18. Specifically, the guide ribs 17 are provided at the air inlet and the rectifying ribs 18 are provided at the air outlet.

[0069] In a specific embodiment, the rotating shaft 28 passes through the axial fixing hole of the upper shell 1 and the axial fixing hole of the lower shell 2 and is fixedly connected to the upper shell 1 and the lower shell 2 .

[0070] Two bearings 3 are fixedly mounted on the upper and lower portions of the rotating shaft 28. Bushings 23 are provided around the outer surfaces of the bearings 3 on the upper and lower portions of the rotating shaft 28. Limiting bushings 30 are provided between adjacent bearings 3 on the upper and lower portions of the rotating shaft 28 to prevent bearing contact and provide position limiting. The axial fixing hole in the upper housing 1 limits upward displacement of the bearing 3 at the upper end of the rotating shaft 28, while the axial fixing hole in the lower housing 2 limits downward displacement of the bearing 3 at the lower end of the rotating shaft 28. The bearings 3 can slide relative to the bushings 23 and the rotating shaft 28, and the bushings 23 can also move axially relative to the rotating shaft 28. Bearing limiting rings 29 are provided at both ends of the bushing 23 to prevent the bearings 3 from sliding out of the bushing 23. In this embodiment, an elastic member 22 is provided between two adjacent bearings 3 within the same bushing 23 to provide elastic force for the two bearings 3.

[0071] A rotor assembly 6 is fixedly provided on the outside of the shaft sleeve 23 for rotating in conjunction with a stator assembly 7 fixedly provided on the outside of the axial fixing hole of the upper shell 1 or the lower shell 2. An inner impeller 8 is fixedly provided on the rotor assembly 6 at the upper part of the rotating shaft 28 for supplying air near the axis in the axial flow fan housing. An outer impeller 9 is fixedly provided on the rotor assembly 6 at the lower part of the rotating shaft 28 for supplying air away from the axis in the axial flow fan housing. The inner impeller 8 and the outer impeller 9 are arranged on the same plane, and the inner impeller blades 10 of the inner impeller 8 are arranged between the outer impeller blades 13 of the outer impeller 9 and the rotor assembly 6. In addition, the space between the outer impeller blades 13 of the outer impeller 9 and the rotor assembly 6 is hollowed out for supplying air to the inner impeller 8.

[0072] In a specific implementation of this embodiment, the outer impeller 9 further includes an outer wheel hub 14, an outer wheel rim 15, and a hub outer ring 16. The outer wheel hub 14 is fixedly mounted on the rotor assembly 6 located at the lower portion of the rotating shaft 28, and the outer wheel hub 14 is evenly and radially outwardly provided with guide ribs 17 or straightening ribs 18 for fixedly connecting the hub outer ring 16. When the inner impeller 8 delivers air downward, the outer wheel hub 14 is evenly and radially outwardly provided with straightening ribs 18; when the inner impeller 8 delivers air upward, the outer wheel hub 14 is evenly and radially outwardly provided with guide ribs 17. The guide ribs 17 are used to guide the airflow and minimize the turbulence of the airflow. The straightening ribs 18 are generally arranged in the air supply direction of the inner wheel blades 10 or the outer wheel blades 13 to adjust the direction of the airflow.

[0073] The blade roots of the outer impeller blades 13 are fixedly mounted on the outer ring 16 of the hub, and the blade tips of the outer impeller blades 13 are fixedly connected to the outer rim 15. Generally, the outer impeller blades 13, the outer hub 14, the outer rim 15, the hub outer ring 16, and the guide ribs 17 or the straightening ribs 18 are integrally formed, which helps to improve the structural strength of the outer impeller 9.

[0074] In addition, the upper and lower sides of the outer wheel rim 15 are fixed with end sealing rings 19, and the inner walls of the upper shell 1 and the lower shell 2 are provided with annular grooves 20, and the end sealing rings 19 extend into the annular grooves 20 to form a dynamic sealing structure. Figure 1 The dynamic seal structures of the illustrated embodiments are identical.

[0075] In the specific implementation of this embodiment, the inner impeller 8 further includes an inner wheel hub 11 and an inner wheel rim 12. The inner wheel hub 11 is fixedly mounted on the rotor assembly 6 above the rotating shaft 28. The roots of the inner wheel blades 10 are fixedly mounted on the inner wheel hub 11, and the tips of the inner wheel blades 10 are fixedly connected to the inner wheel rim 12. The inner wheel blades 10, inner wheel hub 11, and inner wheel rim 12 are integrally formed, which helps to improve the structural strength of the inner impeller 8.

[0076] In addition, an intermediate sealing ring 21 is provided on the upper side of the inner wheel rim 12. The cross section of the intermediate sealing ring 21 is an inverted U-shaped. The upper side of the hub outer ring 16 extends into the intermediate sealing ring 21 to form a dynamic sealing structure. Figure 1 The dynamic seal structure in the illustrated embodiments is the same.

[0077] In this embodiment, an inner impeller 8 and an outer impeller 9 are provided. By increasing the speed of the inner impeller 8, the pressure difference between the inner impeller 8 and the outer impeller 9 is balanced as much as possible to prevent air leakage from the inner impeller 8. When a single impeller is provided, the speed at the impeller blade root is much lower than the speed at the blade tip. At this time, the pressure at the blade tip is greater than the blade root, and air leakage through the blade root will occur, reducing the air supply efficiency of the fan blade.

[0078] In this embodiment, the upper shell 1 and the lower shell 2 are fixedly connected by a flexible fixing member 24. Connecting the upper shell 1 and the lower shell 2 by the flexible fixing member 24 can reduce the transmission efficiency of vibration.

[0079] Specifically, the flexible fixing member 24 includes an upper flexible seat 25, a lower flexible seat 26, and a connecting rod 27. The upper flexible seat 25 and the lower flexible seat 26 have through holes in their centers, through which the connecting rod 27 passes. The ends of the connecting rod 27 extend radially outward, and the diameter of the extension portion is larger than the diameter of the through hole, to prevent the upper flexible seat 25 and the lower flexible seat 26 from falling off the connecting rod 27.

[0080] The side walls of the upper flexible seat 25 and the lower flexible seat 26 both have annular fixing grooves. The snap ring 33 on the upper shell 1 is snapped into the annular fixing groove on the upper flexible seat 25 , and the snap ring 33 on the lower shell 2 is snapped into the annular fixing groove on the lower flexible seat 26 .

[0081] The upper and lower surfaces, side walls and upper and lower surfaces of the upper and lower flexible seats 25 and the lower flexible seats 26 as well as the annular fixing grooves are provided with elastic nipples 32 . The elastic nipples 32 are used to reduce the contact area and thus reduce the vibration transmission.

[0082] The above description is merely an illustrative embodiment of the present invention. Without departing from the concept and principle of the present invention, any equivalent changes and modifications made by those skilled in the art should fall within the scope of protection of the present invention.

Claims

1. A dual-rotor axial flow fan, characterized in that: The axial flow fan comprises: an upper shell (1) and a lower shell (2), wherein the upper shell (1) and the lower shell (2) are coaxially fixedly arranged; An upper rotating shaft (4) is rotatably provided in the axial center fixing hole of the upper shell (1) via a bearing (3), and a lower rotating shaft (5) is rotatably provided in the axial center fixing hole of the lower shell (2) via a bearing (3); The rotor assembly (6) is fixedly provided at both ends adjacent to the upper rotating shaft (4) and the lower rotating shaft (5) via a fixing flange (31). The fixing flange (31) can limit the position of the bearing (3) near the fixing flange (31). The stator assembly (7) is fixedly provided at the axis center of the upper shell (1) and the axis center of the lower shell (2). The rotor assembly (6) and the stator assembly (7) act to drive the rotor assembly (6) to rotate. An inner impeller (8) is fixedly provided on the rotor assembly (6) fixed on the upper rotating shaft (4) and is used for supplying air near the axis in the axial flow fan housing; An outer impeller (9) is fixedly provided on the rotor assembly (6) fixed on the lower rotating shaft (5) and is used for supplying air away from the axis in the axial flow fan housing; The inner impeller (8) and the outer impeller (9) are arranged on the same plane, and the inner impeller blades (10) of the inner impeller (8) are arranged between the outer impeller blades (13) of the outer impeller (9) and the rotor assembly (6).

2. The dual-rotor axial flow fan according to claim 1, characterized in that: The outer impeller (9) further comprises an outer wheel hub (14), an outer wheel rim (15), and a hub outer ring (16), wherein: The outer wheel hub (14) is fixedly arranged on the rotor assembly (6) located on the lower rotating shaft (5), and the outer wheel hub (14) is evenly provided with guide ribs (17) or straightening ribs (18) along the circumference radially outward, which are used for fixed connection with the hub outer ring (16); The blade roots of the outer wheel blades (13) are fixedly arranged on the outer ring (16) of the hub, and the blade tips of the outer wheel blades (13) are fixedly connected to the outer wheel rim (15).

3. The dual-rotor axial flow fan according to claim 2, characterized in that: The upper side and the lower side of the outer wheel rim (15) are fixedly provided with an end sealing ring (19), and the inner wall of the upper shell (1) and the inner wall of the lower shell (2) are both provided with an annular groove (20), and the end sealing ring (19) extends into the annular groove (20) to form a dynamic sealing structure.

4. The dual-rotor axial flow fan according to claim 2 or 3, characterized in that: The inner impeller (8) further includes an inner wheel hub (11) and an inner wheel rim (12), wherein: The inner wheel hub (11) is fixedly arranged on the rotor assembly (6) located on the upper rotating shaft (4), the blade roots of the inner wheel blades (10) are fixedly arranged on the inner wheel hub (11), and the blade tips of the inner wheel blades (10) are fixedly connected to the inner wheel rim (12).

5. The dual-rotor axial flow fan according to claim 4, characterized in that: An intermediate sealing ring (21) is provided on the upper side of the inner wheel rim (12), and the cross section of the intermediate sealing ring (21) is an inverted U-shape. The upper side edge of the hub outer ring (16) extends into the intermediate sealing ring (21) to form a dynamic sealing structure.

6. The dual-rotor axial flow fan according to claim 1, characterized in that: At least two bearings (3) are provided on the upper rotating shaft (4), and an elastic member (22) is provided between the bearing (3) provided at the lower end of the upper rotating shaft (4) and the adjacent bearing (3) for making the upper rotating shaft (4), the bearing (3) provided at the lower end of the upper rotating shaft (4), and the rotor assembly (6) float up and down; At least two bearings (3) are provided on the lower rotating shaft (5), and an elastic member (22) is provided between the bearing (3) provided at the upper end of the lower rotating shaft (5) and the adjacent bearing (3) for making the lower rotating shaft (5), the bearing (3) provided at the upper end of the lower rotating shaft (5), and the rotor assembly (6) float up and down.

7. The dual-rotor axial flow fan according to claim 1, characterized in that: A shaft sleeve (23) is provided in the axial center fixing hole of the upper shell (1) and the lower shell (2), and the bearing (3) is provided in the shaft sleeve (23).

8. The dual-rotor axial flow fan according to claim 4, characterized in that: The upper shell (1) and the lower shell (2) are fixedly connected via a flexible fixing member (24).

9. The dual-rotor axial flow fan according to claim 8, characterized in that: The flexible fixing member (24) comprises an upper flexible seat (25), a lower flexible seat (26) and a connecting rod (27), wherein: The upper flexible seat (25) and the lower flexible seat (26) have through holes in their centers, and the connecting rod (27) passes through the through holes. Both ends of the connecting rod (27) extend radially outward, and the diameter of the extension portion is larger than the diameter of the through hole, so as to prevent the upper flexible seat (25) and the lower flexible seat (26) from falling off from the connecting rod (27); The side walls of the upper flexible seat (25) and the lower flexible seat (26) are both provided with an annular fixing groove; the snap ring (33) on the upper shell (1) is snapped into the annular fixing groove on the upper flexible seat (25); and the snap ring (33) on the lower shell (2) is snapped into the annular fixing groove on the lower flexible seat (26).

10. A dual-rotor axial flow fan, characterized in that: The axial flow fan comprises: an upper shell (1) and a lower shell (2), wherein the upper shell (1) and the lower shell (2) are coaxially fixedly arranged; The rotating shaft (28) passes through the axial fixing hole of the upper shell (1) and the axial fixing hole of the lower shell (2), and is fixedly connected to the upper shell (1) and the lower shell (2); Two bearings (3) are fixedly provided on the upper and lower parts of the rotating shaft (28); the bearings (3) on the upper part of the rotating shaft (28) and the bearings (3) on the lower part of the rotating shaft (28) are both sleeved with shaft sleeves (23); a rotor assembly (6) is fixedly provided on the outside of the shaft sleeve (23) for rotating in conjunction with a stator assembly (7) fixedly provided on the outside of the axial fixing hole of the upper shell (1) or the lower shell (2); A limiting sleeve (30) is provided between the upper portion of the rotating shaft (28) and the adjacent bearings (3) at the lower portion of the rotating shaft (28) to prevent the bearings (3) from contacting and to limit the position; An inner impeller (8) is fixedly provided on the rotor assembly (6) above the rotating shaft (28) and is used to supply air near the axis in the axial flow fan housing; An outer impeller (9) is fixedly provided on the rotor assembly (6) below the rotating shaft (28) and is used to supply air away from the axis in the axial flow fan housing; The inner impeller (8) and the outer impeller (9) are arranged on the same plane, and the inner impeller blades (10) of the inner impeller (8) are arranged between the outer impeller blades (13) of the outer impeller (9) and the rotor assembly (6).

11. The dual-rotor axial flow fan according to claim 10, characterized in that: The outer impeller (9) further comprises an outer wheel hub (14), an outer wheel rim (15), and a hub outer ring (16), wherein: The outer wheel hub (14) is fixedly arranged on the rotor assembly (6) located below the rotating shaft (28), and the outer wheel hub (14) is evenly provided with guide ribs (17) or straightening ribs (18) radially outwardly around the circumference thereof, for fixedly connecting to the hub outer ring (16); The blade roots of the outer wheel blades (13) are fixedly arranged on the outer ring (16) of the hub, and the blade tips of the outer wheel blades (13) are fixedly connected to the outer wheel rim (15).

12. The dual-rotor axial flow fan according to claim 11, characterized in that: The upper side and the lower side of the outer wheel rim (15) are fixedly provided with an end sealing ring (19), and the inner wall of the upper shell (1) and the inner wall of the lower shell (2) are both provided with an annular groove (20), and the end sealing ring (19) extends into the annular groove (20) to form a dynamic sealing structure.

13. The dual-rotor axial flow fan according to claim 11 or 12, characterized in that: The inner impeller (8) further includes an inner wheel hub (11) and an inner wheel rim (12), wherein: The inner wheel hub (11) is fixedly arranged on the rotor assembly (6) located on the upper part of the rotating shaft (28), the blade root of the inner wheel blade (10) is fixedly arranged on the inner wheel hub (11), and the blade tip of the inner wheel blade (10) is fixedly connected to the inner wheel rim (12).

14. The dual-rotor axial flow fan according to claim 13, characterized in that: An intermediate sealing ring (21) is provided on the upper side of the inner wheel rim (12), and the cross section of the intermediate sealing ring (21) is an inverted U-shape. The upper side edge of the hub outer ring (16) extends into the intermediate sealing ring (21) to form a dynamic sealing structure.

15. The dual-rotor axial flow fan according to claim 13, characterized in that: The upper shell (1) and the lower shell (2) are fixedly connected via a flexible fixing member (24).

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