Double-suction centrifugal fan

Abstract

The utility model discloses a double-suction centrifugal fan which comprises a fan shell, a fan cover and a fan cover. An impeller; the outer rotor motor is arranged in the center area of the impeller in a penetrating mode, the outer rotor motor comprises an outer rotor and a stator winding, the stator winding is sleeved with the outer rotor, and the outer rotor is connected with the impeller; and the two current collectors are symmetrically arranged at the two axial end parts of the outer rotor motor, and the current collectors are connected with the connecting shaft of the stator winding. The outer rotor motor is connected with the impeller through the outer rotor to drive the impeller to rotate, and transmission between the outer rotor motor and the impeller is simple and efficient. The outer rotor motor is arranged in the center area of the impeller in a penetrating mode, the center area of the impeller is utilized, the outer rotor motor cannot affect air inlet of the two sides of the impeller, and therefore the air inlet amount of the two sides of the double-suction centrifugal fan is consistent, the structure is compact, and the overall size is small; furthermore, the flow collector not only plays a role in guiding inlet air of the impeller, but also plays a role in supporting the outer rotor motor.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to a double-suction centrifugal fan. Background Technology

[0002] Centrifugal fans are fluid machines that use centrifugal force to accelerate gas and change the direction of airflow. They are widely used in ventilation, cooling, dust removal, and industrial gas transportation. Their core feature is that the airflow direction is perpendicular to the impeller axis, meaning that centrifugal fans use a radial air outlet method.

[0003] Centrifugal fans include two types: single-suction centrifugal fans and double-suction centrifugal fans. Single-suction centrifugal fans have only one air inlet. One side of the impeller of a single-suction centrifugal fan is closed, while the other side of the impeller is open and connected to the air inlet. Double-suction centrifugal fans have two air inlets. Both sides of the impeller of a double-suction centrifugal fan are open and connected to the corresponding air inlets.

[0004] In related technologies, the impeller of a double-suction centrifugal fan is often directly driven by an internal rotor motor. In this technical solution, the output shaft of the internal rotor motor is connected to the impeller shaft via a coupling. To improve transmission efficiency, the output shaft of the internal rotor motor and the impeller shaft are generally coaxial. This means the main body of the internal rotor motor needs to be located at the air inlet of the double-suction centrifugal fan. Consequently, the internal rotor motor and its mounting structure obstruct air intake on one side of the double-suction centrifugal fan, resulting in inconsistent airflow on both sides. Furthermore, the internal rotor motor and its mounting structure occupy the side space of the double-suction centrifugal fan, increasing its width. This makes installation difficult in situations with limited space or special structural requirements, such as in a sweeper's fan system.

[0005] In related technologies, the impeller of a double-suction centrifugal fan can also be indirectly driven by an internal rotor motor and a transmission mechanism. For example, the internal rotor motor can drive a belt pulley transmission mechanism to indirectly drive the impeller of the double-suction centrifugal fan to rotate. In the technical solution of using a belt pulley transmission mechanism for transmission, the internal rotor motor and the motor mounting structure can be set at a position away from the air inlet of the double-suction centrifugal fan. However, the belt pulley transmission mechanism still needs to be set at a position away from the air inlet on one side of the double-suction centrifugal fan. Although this can reduce the impact of the internal rotor motor and the motor mounting structure on the air inlet on one side of the double-suction centrifugal fan, the internal rotor motor, the motor mounting structure, and the belt pulley transmission mechanism increase the complexity of the structure. Utility Model Content

[0006] To overcome at least one of the defects of the prior art, this utility model provides a double-suction centrifugal fan with an external rotor motor. The external rotor motor is connected to the impeller via an external rotor to drive the impeller to rotate. The transmission between the external rotor motor and the impeller is simple and efficient. Moreover, the external rotor motor is located in the central area of ​​the impeller, utilizing the central area of ​​the impeller. The external rotor motor does not affect the air intake on both sides of the impeller, thus the double-suction centrifugal fan has consistent air intake on both sides, a compact structure, and a small overall size. Furthermore, the collectors are symmetrically arranged at both axial ends of the external rotor motor and are connected to the connecting shaft of the stator winding. The collectors not only guide the air intake of the impeller but also support the external rotor motor.

[0007] The technical solution adopted by this utility model to solve its problem is:

[0008] A dual-suction centrifugal fan, comprising:

[0009] The fan housing has one air outlet and two air inlets, all of which are connected to the inner cavity of the fan housing.

[0010] The impeller is located inside the fan casing, and two air inlets are located on both sides of the impeller.

[0011] An external rotor motor is installed in the central area of ​​the impeller. The external rotor motor includes an external rotor and a stator winding. The external rotor is sleeved outside the stator winding and is connected to the impeller.

[0012] The current collectors are symmetrically arranged at both ends of the axial direction of the external rotor motor, and the current collectors are connected to the connecting shaft of the stator winding.

[0013] As an optional implementation, the impeller includes a front disc, a middle disc, a rear disc, and multiple blades, which are interconnected.

[0014] The front disc, middle disc, and rear disc are arranged sequentially along the central axis of the impeller. Multiple blades are arranged at intervals between the front disc and the middle disc, and multiple blades are arranged at intervals between the middle disc and the rear disc, along with the central axis of the impeller.

[0015] The front disc and / or the middle disc and / or the rear disc are connected to the outer rotor, which drives the impeller to rotate.

[0016] As an optional implementation, the external rotor motor also includes a motor housing, which is disposed outside the external rotor and connected to the external rotor;

[0017] The connection between the intermediate plate and the motor housing is provided with a snap-fit ​​structure in the middle of the outer side wall of the motor housing for snapping with the intermediate plate. The snap-fit ​​structure includes a first snap-fit ​​part and / or a second snap-fit ​​part, both of which limit the impeller.

[0018] As an optional implementation, the dual-suction centrifugal fan also includes a bearing assembly, which includes a first bearing and a second bearing;

[0019] One end of the stator winding has a first connecting shaft, and the other end of the stator winding has a second connecting shaft. A first bearing is sleeved on the first connecting shaft of the stator winding and is located between the stator winding and the motor housing. A second bearing is sleeved on the second connecting shaft of the stator winding and is located between the stator winding and the motor housing.

[0020] As an optional implementation, the collector includes a sleeve, a collector body, and multiple guide plates. The collector body is located in the central area of ​​the sleeve, and the multiple guide plates are spaced around the periphery of the collector body. One end of the guide plate is connected to the collector body, and the other end of the guide plate is connected to the sleeve.

[0021] The sleeve is connected to the fan casing, and the current collector is connected to the connecting shaft of the stator winding.

[0022] As an optional implementation, the flow collecting body has a conical tip, a first inclined section is formed from the top of the flow collecting body toward the bottom of the flow collecting body, and a second inclined section is formed from the root of the guide plate toward the top of the guide plate.

[0023] There is an angle between the first inclined segment and the second inclined segment, and the value of the angle ranges from 60° to 120°.

[0024] As an alternative implementation, the sleeve has a first arc-shaped section in its cylindrical body and a second arc-shaped section in its impeller, with at least one intersection point between the extending directions of the first and second arc-shaped sections.

[0025] As an optional implementation, the deflector is a three-dimensional deflector.

[0026] As an optional implementation, the impeller, external rotor motor, and collector are arranged coaxially.

[0027] As an alternative implementation, the fan casing is volute-shaped, and the air outlet is located at the upper part or the lower part of the fan casing.

[0028] In summary, this utility model has the following technical advantages: The utility model features an external rotor motor, which is connected to the impeller via an external rotor to drive the impeller to rotate. The transmission between the external rotor motor and the impeller is simple and efficient. Furthermore, the external rotor motor is positioned in the central area of ​​the impeller, utilizing this central area without affecting the air intake on both sides of the impeller. This results in consistent air intake on both sides of the double-suction centrifugal fan, a compact structure, and a smaller overall size. Further, the collectors are symmetrically arranged at both axial ends of the external rotor motor and are connected to the stator winding shaft. The collectors not only guide the air intake of the impeller but also support the external rotor motor. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the external structure from a first perspective of Embodiment 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of the internal structure from a second perspective of Embodiment 1 of this utility model;

[0032] Figure 3 This is Embodiment 1 of the present utility model. Figure 2 A schematic diagram of the first partial structure;

[0033] Figure 4 This is Embodiment 1 of the present utility model. Figure 2 A schematic diagram of the second local structure;

[0034] Figure 5 This is a schematic diagram of the internal structure from a second perspective of Embodiment 2 of this utility model;

[0035] Figure 6 This is embodiment 2 of the present utility model. Figure 5 A partial structural diagram.

[0036] The meanings of the reference numerals in the attached figures are as follows:

[0037] 10. Fan casing; 20. Air outlet; 30. Air inlet; 40. Impeller; 401. Front disc; 402. Middle disc; 403. Rear disc; 404. Blade; 50. External rotor motor; 501. External rotor; 502. Stator winding; 503. Motor casing; 504. Snap-fit ​​structure; 5041. First snap-fit ​​part; 5042. Second snap-fit ​​part; 60. Collector; 601. Sleeve; 602. Collector body; 603. Guide plate; 604. Second connecting hole; 605. First inclined section; 606. Second inclined section; 607. First arc-shaped section; 70. Bearing assembly; 701. First bearing; 702. Second bearing; 80. First connecting hole; 90. Second arc-shaped section. Detailed Implementation

[0038] 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.

[0039] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0040] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0041] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0042] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0043] The technical solution of this utility model will be further described below with reference to the embodiments and accompanying drawings.

[0044] Example 1

[0045] See Figures 1 to 4 This utility model discloses a double-suction centrifugal fan, comprising: a fan housing 10, the fan housing 10 having one air outlet 20 and two air inlets 30, the air outlet 20 and the two air inlets 30 being connected to the inner cavity of the fan housing 10; an impeller 40, the impeller 40 being disposed in the inner cavity of the fan housing 10, the two air inlets 30 being respectively disposed on both sides of the impeller 40; an external rotor motor 50, the external rotor motor 50 being disposed in the central area of ​​the impeller 40, the external rotor motor 50 including an external rotor 501 and a stator winding 502, the external rotor 501 being sleeved on the outside of the stator winding 502, and the external rotor 501 being connected to the impeller 40; and two collectors 60, two collectors 60 being symmetrically disposed at the two axial ends of the external rotor motor 50, and the collectors 60 being connected to the connecting shaft of the stator winding 502.

[0046] This utility model features an external rotor motor 50, which is connected to the impeller 40 via an external rotor 501 to drive the impeller 40 to rotate. The transmission between the external rotor motor 50 and the impeller 40 is simple and efficient. Moreover, the external rotor motor 50 is installed in the central area of ​​the impeller 40, utilizing the central area of ​​the impeller 40. The external rotor motor 50 does not affect the air intake on both sides of the impeller 40, thus ensuring consistent air intake on both sides of the double-suction centrifugal fan, a compact structure, and a small overall size. Furthermore, collectors 60 are symmetrically arranged at both axial ends of the external rotor motor 50, and the collectors 60 are connected to the connecting shaft of the stator winding 502. The collectors 60 not only guide the air intake of the impeller 40 but also support the external rotor motor 50.

[0047] It should be noted that the impeller 40 is directly driven by the external rotor motor, and the output power of the external rotor motor acts directly on the impeller 40. Therefore, the mechanical transmission efficiency of this double-suction centrifugal fan is higher than that of indirect transmission mechanisms such as belt pulley transmission. The external rotor motor is adapted to the frequent speed adjustment characteristics of the double-suction centrifugal fan and can withstand the aerodynamic impact load when the impeller 40 is adjusted. The power range of the double-suction centrifugal fan covers, but is not limited to, 11kW-315kW.

[0048] It should be noted that the two air inlets 30 are respectively located on both sides of the impeller 40, for example, see [reference]. Figure 2 as well as Figure 3 The two air inlets 30 are respectively located on the left and right sides of the impeller 40.

[0049] It should be noted that the external rotor motor 50 can be an existing external rotor motor, such as a permanent magnet external rotor motor. In a permanent magnet external rotor motor, the stator winding is usually made of silicon steel sheets laminated together and has three-phase windings or other types of windings embedded in it. The rotor is made of permanent magnets (such as neodymium iron boron). The permanent magnets are arranged in alternating polarities to form a permanent magnet magnetic field. When alternating current (or direct current through electronic commutation) is applied to the stator winding, a rotating magnetic field is generated. The permanent magnet magnetic field on the rotor interacts with the rotating magnetic field of the stator winding to generate electromagnetic torque, which drives the rotor to rotate. Of course, the external rotor motor 50 can be other existing external rotor motors and is not limited thereto.

[0050] In this embodiment of the present invention, the impeller 40 includes a front disc 401, a middle disc 402, a rear disc 403, and a plurality of blades 404. The front disc 401, the middle disc 402, the rear disc 403, and the plurality of blades 404 are interconnected. The front disc 401, the middle disc 402, and the rear disc 403 are arranged sequentially at intervals along the central axis of the impeller 40. The front disc 401 and the middle disc 402 are arranged at intervals around the central axis of the impeller 40, and the middle disc 402 and the rear disc 403 are arranged at intervals around the central axis of the impeller 40. The front disc 401 and / or the middle disc 402 and / or the rear disc 403 are connected to an outer rotor 501, which drives the impeller 40 to rotate.

[0051] In other words, at least one of the front disc 401, the middle disc 402, and the rear disc 403 is connected to the outer rotor 501.

[0052] It should be noted that, in order to ensure consistent airflow on both sides of the impeller 40, the middle disc 402 is connected to the outer rotor 501, or the front disc 401, middle disc 402, and rear disc 403 are all connected to the outer rotor 501; naturally, for the purpose of symmetry on both sides of the impeller 40, the blades on both sides of the middle disc 402 are symmetrically arranged, for example... Figure 2 as well as Figure 3 In the middle, the blades are symmetrically arranged on the left and right sides of the middle plate 402.

[0053] In this embodiment of the utility model, the outer rotor motor 50 further includes a motor housing 503, which is disposed outside the outer rotor 501 and connected to the outer rotor 501; the connection between the middle plate body 402 and the motor housing 503 is provided with a snap-fit ​​structure 504 for snapping with the middle plate body 402 in the middle of the outer side wall of the motor housing 503. The snap-fit ​​structure 504 includes a first snap-fit ​​part 5041, which limits the impeller 40.

[0054] For example, see Figure 4 The motor housing 503 and the outer rotor 501 are manufactured separately and then connected as one unit by snap-fit ​​and welding, so that the motor housing 503 and the outer rotor 501 can rotate as one unit.

[0055] Furthermore, the snap-fit ​​structure 504 and the outer rotor 501 are manufactured separately and then connected as a whole by welding, or the snap-fit ​​structure 504 and the outer rotor 501 are manufactured as a whole.

[0056] An "L"-shaped limiting step is formed on the first locking part 5041, so that the middle plate 402 is locked with the first locking part 5041. After the middle plate 402 is locked with the first locking part 5041, it can be further welded to increase the stability of the connection. The first locking part 5041 limits the middle plate 402 in the axial direction and the radial direction. In this way, when the impeller 40 rotates with the outer rotor 501, even if the impeller 40 is subjected to the centrifugal force of rotation, the impeller 40 can still be connected to the motor housing 503 and the outer rotor 501 in a relatively stable manner.

[0057] In this embodiment of the utility model, the double-suction centrifugal fan further includes a bearing assembly 70, which includes a first bearing 701 and a second bearing 702; one end of the stator winding 502 has a first connecting shaft, and the other end of the stator winding 502 has a second connecting shaft; the first bearing 701 is sleeved on the first connecting shaft of the stator winding 502 and is disposed between the stator winding 502 and the motor housing 503; the second bearing 702 is sleeved on the second connecting shaft of the stator winding 502 and is disposed between the stator winding 502 and the motor housing 503.

[0058] It should be noted that, due to the presence of the first bearing 701 and the second bearing 702, the integrated structure of the impeller 40, the motor housing 503 and the outer rotor 501 can rotate more smoothly relative to the stator winding 502. Moreover, the first bearing 701 and the second bearing 702 are both located between the stator winding 502 and the outer rotor 501, making the installation of the first bearing 701 and the second bearing 702 more convenient.

[0059] In this embodiment of the utility model, the collector 60 includes a sleeve 601, a collector body 602, and a plurality of guide plates 603. The collector body 602 is disposed in the central region of the sleeve 601, and the plurality of guide plates 603 are arranged at intervals around the periphery of the collector body 602. One end of the guide plate 603 is connected to the collector body 602, and the other end of the guide plate 603 is connected to the sleeve 601. The sleeve 601 is connected to the fan housing 10, and the collector body 602 is connected to the connecting shaft of the stator winding 502.

[0060] For example, see Figure 2 as well as Figure 3 The fan housing 10 is provided with a first connection hole 80, and the sleeve 601 is inserted into the first connection hole 80. The collector 60 is connected to the fan housing 10 through the first connection hole 80.

[0061] Continue reading Figure 2 as well as Figure 3 The current collector body 602 is provided with a second connecting hole 604. The first connecting shaft of the stator winding 502 is inserted into the second connecting hole 604 of the corresponding current collector body 602, and the second connecting shaft of the stator winding 502 is inserted into the second connecting hole 604 of the corresponding other current collector body 602.

[0062] It should be noted that a flow channel is formed between the two guide plates 603. This flow channel is connected to the inner cavity of the fan casing 10. The main body 602 introduces the airflow into the flow channel to form a pre-swirl and reduce the intake resistance.

[0063] The fan casing 10, collector 60 and stator winding 502 are connected as one unit. The integrated structure formed by the fan casing 10, collector 60 and stator winding 502 is fixed relative to the integrated structure formed by the impeller 40, motor casing 503 and outer rotor 501. Two collectors 60 are symmetrically connected to both ends of the stator winding 502, thereby providing balanced and stable support to both ends of the stator winding 502.

[0064] Furthermore, when the stator winding 502 is connected to the two current collectors 60, the first connecting shaft of the stator winding 502 is inserted into the second connecting hole 604 of the corresponding current collector body 602, and the second connecting shaft of the stator winding 502 is inserted into the second connecting hole 604 of the corresponding other current collector body 602, which facilitates assembly.

[0065] In this embodiment of the utility model, the flow collecting body 602 has a tapered tip, and a first inclined section 605 is formed from the top of the flow collecting body 602 toward the bottom of the flow collecting body 602. A second inclined section 606 is formed from the root of the guide plate 603 toward the top of the guide plate 603. There is an angle between the first inclined section 605 and the second inclined section 606, and the value of the angle is in the range of 60°-120°.

[0066] For example, see Figure 2 as well as Figure 3 The angle between the first inclined section 605 and the second inclined section 606 is 110°. The first inclined section 605 is used to introduce the airflow into the guide channel formed between the two guide plates 603 along the extension direction of the first inclined section 605. The second inclined section 606 is used to introduce the airflow into the guide channel formed between the two guide plates 603 along the extension direction of the second inclined section 606, thereby reducing the intake resistance.

[0067] In this embodiment of the present invention, the cylindrical portion of the sleeve 601 has a first arc-shaped segment 607, and the impeller 40 has a second arc-shaped segment 90. The extending direction of the first arc-shaped segment 607 and the extending direction of the second arc-shaped segment 90 have at least one intersection point.

[0068] For example, see Figure 2 as well as Figure 3 There is a rotational clearance between the sleeve 601 and the impeller 40, so that the sleeve 601 and the impeller 40 will not interfere with each other.

[0069] The first arc-shaped section 607 is used to introduce airflow into the inner cavity of the fan housing 10 along the extension direction of the first arc-shaped section 607, and the second arc-shaped section 90 is used to introduce airflow into the inner cavity of the fan housing 10 along the extension direction of the second arc-shaped section 90, thereby reducing the intake resistance.

[0070] When the extension direction of the first arc segment 607 and the extension direction of the second arc segment 90 have two or more intersection points, the extension direction of the first arc segment 607 and the extension direction of the second arc segment 90 partially coincide, thereby forming an arc transition between the extension direction of the first arc segment 607 and the extension direction of the second arc segment 90, which further facilitates the introduction of airflow into the inner cavity of the fan casing 10 and further reduces the intake resistance.

[0071] In this embodiment of the utility model, the guide plate 603 is a ternary guide plate.

[0072] It should be noted that the deflector 603 has a spatially twisted shape. The deflector 603 is transversely cut at equal intervals along the direction from the root to the top. The installation angle of section 1 is a1, the installation angle of section 2 is a2, the installation angle of section 3 is a3, the installation angle of section 4 is a4, the installation angle of section 5 is a5, and the installation angle of section 6 is a6, where a1 > a2 > a3 > a4 > a5 > a6.

[0073] Thus, the root of the guide plate 603 has a large installation angle, and the top of the guide plate 603 has a small installation angle. The three-dimensional guide plate can make the airflow entering the impeller 40 pre-rotate in advance during the operation of the double-suction centrifugal fan, reduce the intake resistance, and effectively reduce the blade separation loss caused by excessive or insufficient angle of attack when deviating from the design point area, thus widening the high-efficiency zone of the impeller 40.

[0074] In this embodiment of the utility model, the impeller 40, the external rotor motor 50, and the collector 60 are arranged coaxially.

[0075] See Figure 2 as well as Figure 3 In the external rotor motor 50, the motor housing 503, the external rotor 501, and the stator winding 502 are also coaxially arranged. The wires of the stator winding 502 can be led out from the current collector 60 without affecting the rotation of the impeller 40 and the stator winding 502.

[0076] In this embodiment of the utility model, the fan housing 10 is volute-shaped, and the air outlet 20 is located on the upper part or the lower part of the fan housing 10.

[0077] For example, see Figure 1 The air outlet 20 is located on the upper part of the fan casing 10. Of course, the specific location of the air outlet 20 depends on the actual application scenario and is not limited.

[0078] Example 2

[0079] See Figures 5 to 6 In this embodiment of the utility model, unlike Embodiment 1, the outer rotor motor 50 also includes a motor housing 503, which is disposed outside the outer rotor 501 and connected to the outer rotor 501; the connection between the middle plate body 402 and the motor housing 503 is such that a snap-fit ​​structure 504 for snapping with the middle plate body 402 is provided in the middle of the outer side wall of the motor housing 503. The snap-fit ​​structure 504 includes a first snap-fit ​​part 5041 and a second snap-fit ​​part 5042, both of which limit the impeller 40.

[0080] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A double-suction centrifugal fan, characterized in that, include: A fan housing, the fan housing having one air outlet and two air inlets, the air outlet and the two air inlets being connected to the inner cavity of the fan housing; An impeller is disposed within the inner cavity of the fan casing, and two air inlets are respectively disposed on both sides of the impeller; An external rotor motor is disposed in the central region of the impeller. The external rotor motor includes an external rotor and a stator winding. The external rotor is sleeved outside the stator winding and is connected to the impeller. Two current collectors are symmetrically arranged at the two axial ends of the external rotor motor, and the current collectors are connected to the connecting shaft of the stator winding.

2. The double-suction centrifugal fan according to claim 1, characterized in that: The impeller includes a front disc, a middle disc, a rear disc, and multiple blades, and the front disc, the middle disc, the rear disc, and the multiple blades are interconnected. The front disc, the middle disc, and the rear disc are arranged sequentially at intervals along the central axis of the impeller. A plurality of blades are arranged at intervals between the front disc and the middle disc and around the central axis of the impeller. A plurality of blades are also arranged at intervals between the middle disc and the rear disc and around the central axis of the impeller. The front disc and / or the middle disc and / or the rear disc are connected to the outer rotor, and the outer rotor drives the impeller to rotate.

3. The double-suction centrifugal fan according to claim 2, characterized in that: The external rotor motor also includes a motor housing, which is disposed outside the external rotor and connected to the external rotor; The connection between the middle plate and the motor housing is provided with a snap-fit ​​structure in the middle of the outer side wall of the motor housing for snapping with the middle plate. The snap-fit ​​structure includes a first snap-fit ​​part and / or a second snap-fit ​​part, both of which limit the impeller.

4. The double-suction centrifugal fan according to claim 3, characterized in that: The dual-suction centrifugal fan also includes a bearing assembly, which includes a first bearing and a second bearing; One end of the stator winding has a first connecting shaft, and the other end of the stator winding has a second connecting shaft. The first bearing is sleeved on the first connecting shaft of the stator winding and is disposed between the stator winding and the motor housing. The second bearing is sleeved on the second connecting shaft of the stator winding and is disposed between the stator winding and the motor housing.

5. The double-suction centrifugal fan according to any one of claims 1-4, characterized in that: The collector includes a sleeve, a collector body, and multiple guide plates. The collector body is disposed in the central region of the sleeve, and the multiple guide plates are spaced around the periphery of the collector body. One end of each guide plate is connected to the collector body, and the other end of each guide plate is connected to the sleeve. The sleeve is connected to the fan housing, and the current collector is connected to the connecting shaft of the stator winding.

6. The double-suction centrifugal fan according to claim 5, characterized in that: The main body of the flow collector has a conical tip, and a first inclined section is formed from the top of the main body of the flow collector toward the bottom of the main body of the flow collector, and a second inclined section is formed from the root of the guide plate toward the top of the guide plate. The first inclined segment and the second inclined segment have an included angle, the included angle being in the range of 60°-120°.

7. The double-suction centrifugal fan according to claim 5, characterized in that: The sleeve has a first arc-shaped section in its cylindrical body and the impeller has a second arc-shaped section. The extension direction of the first arc-shaped section and the extension direction of the second arc-shaped section have at least one intersection point.

8. The double-suction centrifugal fan according to claim 5, characterized in that: The guide plate is a ternary guide plate.

9. The double-suction centrifugal fan according to any one of claims 1-4, characterized in that: The impeller, the external rotor motor, and the collector are arranged coaxially.

10. The double-suction centrifugal fan according to any one of claims 1-4, characterized in that: The fan casing is volute-shaped, and the air outlet is located at the upper part or the lower part of the fan casing.

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