An outer rotor AC motor axial flow fan

Abstract

This invention discloses an external rotor AC motor axial flow fan, belonging to the field of motor technology. It includes components such as a main shaft, bushing, reinforcing plate, rotor housing, rotor blades, cast aluminum rotor, mounting base, and end covers. A bushing is fitted onto the outer side of the main shaft, and a reinforcing plate and rotor housing are installed on the outer side of the bushing. Rotor blades of the same material are welded to the outer side of the rotor housing, and a cast aluminum rotor is pressed into the inner side. The cast aluminum rotor consists of a rotor core and rotor guide bars. The rotor guide bars are made of pure aluminum and directly cast onto the rotor core. Insulating frames and protective covers are installed at both the front and rear ends of the cast aluminum stator. This invention optimizes materials and structure; the pure aluminum rotor improves performance and reduces energy consumption; the same-material blades and protective sleeve enhance welding strength; the sealing structure improves waterproofing; the structure is reasonable, assembly is convenient, and service life is extended. It solves the defects of traditional fans and is applicable to multiple fields.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to an external rotor AC motor axial flow fan. Background Technology

[0002] Axial flow fans are a type of fan that relies on the axial thrust generated by the rotation of an impeller to transport gas. They are widely used in various fields such as industrial production and civil construction. Due to their advantages such as compact structure and convenient installation, external rotor AC motor axial flow fans have become one of the mainstream products on the market.

[0003] The traditional assembly steps for an external rotor axial flow fan are as follows: the rotor squirrel cage is cast in aluminum and supported by the shaft, and the entire assembly is die-cast; the cast aluminum is made of aluminum alloy; the fan blades are directly welded to the outer circumference of the rotor. While this method simplifies some processes, it has significant technical drawbacks: Firstly, the low conductivity of aluminum alloy leads to poor rotor performance, affecting the fan's efficiency and energy consumption, resulting in low cost-effectiveness; secondly, the different materials of the fan blades and the outer circumference of the rotor result in inconsistent conductivity, poor welding process, and weak welds. During operation, the fan blades are prone to detachment or deformation, leading to fan failure and posing a safety hazard; furthermore, this assembly method has poor waterproofing, making internal components susceptible to corrosion and damage due to moisture intrusion, thus affecting the fan's service life.

[0004] In view of this, the inventors hope to optimize and improve the traditional external rotor motor axial flow fan. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned problems in the prior art and provide an external rotor AC motor axial flow fan that optimizes structural design and material selection, improves motor performance, welding strength and waterproofing effect, reduces production costs and extends service life.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: This invention provides an external rotor AC motor axial flow fan, comprising a main shaft, a bushing, a reinforcing plate, a rotor housing, rotor blades, a cast aluminum rotor, a mounting base, end covers, a front bearing, a rear bearing, bearing caps, a cast aluminum stator, an insulating frame, and protective covers. The bushing, front bearing, rear bearing, and bearing cap are sequentially mounted on the outer side of the main shaft. A reinforcing plate and a rotor housing are mounted on the outer side of the bushing. Rotor blades of the same material are mounted on the outer side of the rotor housing. A cast aluminum rotor, consisting of a rotor core and rotor guide bars, is mounted on the inner side of the mounting base. A cast aluminum stator, sleeved on the outer sides of the front and rear bearings, is supported at the center of the inner side of the mounting base. Insulating frames and protective covers are mounted on the front and rear ends of the cast aluminum stator.

[0007] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the inner side of the rotor core is provided with several rotor slots along the circumferential direction, and the rotor slots are sequentially composed of a slot bottom, a slot shoulder, and a slot opening.

[0008] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the rotor guide bar is a squirrel cage structure composed of a guide bar portion and end ring portions located at both ends thereon. The shape of the guide bar portion matches the shape of the rotor slot. The outer diameter of the end ring portion is smaller than the outer diameter of the rotor core, and the inner diameter of the end ring portion is larger than the inner diameter of the rotor core.

[0009] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the rotor guide bars are made of pure aluminum material and directly cast onto the rotor core.

[0010] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the reinforcing plate is composed of a convex tube portion and a reinforcing plate portion disposed around it, and the reinforcing plate portion is provided with several radial reinforcing arches around the convex tube portion.

[0011] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the rotor housing is composed of a front end plate, a cylindrical tube, and a sealing flange in sequence. The center of the front end plate is provided with a clearance hole that mates with the bushing. The reinforcing plate is welded and installed on the outside of the front end plate. The rotor blades are welded and installed on the outside of the cylindrical tube. The cast aluminum rotor is pressed into the cylindrical tube of the rotor housing using an interference fit method.

[0012] Furthermore, in the aforementioned external rotor AC motor axial flow fan, both the rotor blades and the rotor housing are made of iron.

[0013] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the inner wall of the cast aluminum stator is provided with a stepped limiting groove that mates with the front bearing and the rear bearing.

[0014] Furthermore, in the aforementioned external rotor AC motor axial flow fan, the end cover is composed of a rear end plate, a stepped cylinder, and a water baffle ring in sequence. The mounting base is installed on the inner side of the rear end plate, and the water baffle ring is sleeved on the outer side of the sealing flange.

[0015] Furthermore, in the aforementioned external rotor AC motor axial flow fan, a dust cover is installed on the outer side of the end cover located on the rear end plate, and a mesh cover is installed on the outer side of the dust cover.

[0016] The beneficial effects of this invention are: 1. Improve motor performance, reduce energy consumption, and enhance cost-effectiveness: In this invention, the rotor guide bars are made of pure aluminum material and directly cast on the rotor core. Compared with traditional alloy aluminum material, pure aluminum has higher conductivity, which can effectively optimize rotor performance and improve the working efficiency of the fan. At the same time, the procurement and processing costs of pure aluminum material are lower, balancing performance and economy, and significantly improving the cost-effectiveness of the product.

[0017] 2. Enhanced welding strength and elimination of safety hazards: The rotor blades and rotor housing are made of the same iron material, and their conductivity and coefficient of thermal expansion are consistent, which significantly improves the welding process. The connection after welding is more robust, effectively avoiding problems such as weak welding, blade detachment or deformation caused by different materials of the blades and rotor in traditional fans. It also eliminates product failure caused by blade failure during fan operation, eliminates safety hazards, and improves the stability and reliability of fan operation.

[0018] 3. Optimized waterproof structure and extended service life: The rear end of the rotor housing is equipped with a sealing flange, and the front end of the end cover is equipped with a water-retaining ring. Through the cooperation of the sealing flange and the water-retaining ring, an effective waterproof sealing barrier is formed, which can effectively prevent water vapor from entering the inside of the fan and avoid internal components such as the main shaft, bushing, and rotor from being corroded and damaged by water vapor, thus significantly extending the service life of the fan.

[0019] Of course, any product implementing this invention does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial cross-sectional view of part of the present invention; Figure 3 This is a schematic diagram of the structure of part of the present invention; Figure 4 This is an assembly diagram of the spindle, bushing, and reinforcing plate in this invention; Figure 5 This is a schematic diagram of the reinforcing plate in this invention; Figure 6 This is a schematic diagram of the assembly of the rotor housing and end cover in this invention; Figure 7 This is a schematic diagram of the rotor core structure in this invention; Figure 8 This is a schematic diagram of the rotor slot composition in this invention; Figure 9 This is a schematic diagram of the rotor guide bar in this invention; Figure 10 This is a half-sectional schematic diagram of the rotor guide bar in this invention; In the attached diagram, the components represented by each number are as follows: 1-Main shaft, 2-Sleeve, 3-Reinforcing plate, 301-Protruding tube, 302-Reinforcing plate, 303-Radial reinforcing arch, 4-Rotor housing, 401-Front end plate, 402-Cylindrical cylinder, 403-Sealing flange, 404-Allowing hole, 5-Rotor fan blade, 6-Rotor core, 601-Rotor slot, 601a-Slot bottom, 601b-Slot shoulder, 601c-Slot opening, 7-Rotor guide bar, 701-Guide bar, 702-End ring, 8-Mounting seat, 9-End cover, 901-Rear end plate, 902-Stepped cylinder, 903-Water baffle ring, 10-Dust cover, 11-Mesh cover, 12-Front bearing, 13-Rear bearing, 14-Bearing cap, 15-Cast aluminum stator, 16-Insulating frame, 17-Cover. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figures 1-10 As shown, this embodiment provides an external rotor AC motor axial flow fan, including a main shaft 1, a bushing 2, a reinforcing plate 3, a rotor housing 4, a rotor fan blade 5, a cast aluminum rotor, a mounting base 8, an end cover 9, a front bearing 12, a rear bearing 13, a bearing cap 14, a cast aluminum stator 15, an insulating frame 16, and a protective cover 17. The components work together to achieve stable and efficient operation of the fan, while solving the technical defects of traditional fans.

[0024] As the core support component of the fan, the main shaft 1 is fitted with a bushing 2, a front bearing 12, a rear bearing 13, and a bearing cap 14 from left to right on its outer side. The bushing 2 is interference-fitted with the main shaft 1, which serves to fix and protect the main shaft 1 and prevent the main shaft 1 from shaking or wearing during high-speed rotation. The front bearing 12 and the rear bearing 13 are deep groove ball bearings, which can effectively reduce the friction when the main shaft 1 rotates and improve the smoothness of the fan operation. The bearing cap 14 is fitted on the outside of the rear bearing 13 to prevent slippage between the bearing and the main shaft 1.

[0025] A reinforcing plate 3 and a rotor housing 4 are fixedly installed on the outer side of the bushing 2. The reinforcing plate 3 is located at the front end of the rotor housing 4. The reinforcing plate 3 is composed of a convex tube portion 301 and a reinforcing plate portion 302 located on its periphery. The convex tube portion 301 is welded and fixed to the bushing 2. The reinforcing plate portion 302 has 6 evenly distributed radial reinforcing arches 303 around the convex tube portion 301. The radial reinforcing arches 303 extend radially along the reinforcing plate portion 302, which can significantly improve the structural strength and load-bearing capacity of the reinforcing plate 3, prevent the reinforcing plate 3 from deforming during the operation of the fan, and thus ensure the stability of the entire fan structure.

[0026] The rotor housing 4 is composed of a front end plate 401, a cylindrical tube 402, and a sealing flange 403, which are integrally formed, resulting in a compact structure and good sealing performance. The center of the front end plate 401 is provided with a clearance hole 404 that mates with the bushing 2. The inner diameter of the clearance hole 404 matches the outer diameter of the bushing 2, ensuring that the bushing 2 can pass smoothly through the front end plate 401 while ensuring a uniform gap between the two, reducing shaking during operation. The reinforcing plate 3 is welded to the outside of the front end plate 401, and the welding joint adopts a full welding process to ensure a firm connection and prevent it from falling off. The rotor fan blade 5 is welded to the outside of the rotor housing 4. Both the rotor fan blade 5 and the rotor housing 4 are made of iron material, and their electrical conductivity and thermal expansion coefficient are completely consistent, resulting in excellent welding processability and a tight connection after welding. This effectively solves the problems of weak welding and fan blade detachment caused by the different materials of the fan blade and rotor in traditional fans.

[0027] A cast aluminum rotor is installed inside the rotor housing 4. The cast aluminum rotor consists of a rotor core 6 and rotor guide bars 7, which are pressed into the cylindrical tube 402 of the rotor housing 4 using an interference fit method. This method is convenient to assemble and provides a firm connection, preventing displacement of the cast aluminum rotor during high-speed rotation. The rotor core 6 is formed by stamping and stacking silicon steel sheets, while the rotor guide bars 7 are made of pure aluminum and directly cast onto the rotor core 6. Compared to traditional alloy aluminum, pure aluminum has higher conductivity, which can effectively optimize motor performance, reduce energy loss, and improve the working efficiency of the fan. At the same time, the procurement and processing costs of pure aluminum are lower, balancing performance and economy.

[0028] The inner side of the rotor core 6 has several evenly distributed rotor slots 601 along its circumference. Each rotor slot 601 is composed of a slot bottom 601a, a slot shoulder 601b, and a slot opening 601c. The slot bottom 601a has an arc-shaped structure, the slot shoulder 601b has an inclined structure, and the slot opening 601c has a rectangular structure. This three-section structure design effectively improves the installation stability of the rotor guide bar 7. The rotor guide bar 7 is a squirrel cage structure composed of a guide bar portion 701 and end ring portions 702 located at both ends. The shape of the guide bar portion 701 matches the shape of the rotor slot 601, allowing it to be precisely embedded inside the rotor slot 601. The outer diameter of the end ring portion 702 is smaller than the outer diameter of the rotor core 6, while the inner diameter of the end ring portion 702 is larger than the inner diameter of the rotor core 6, ensuring that the end ring portion 702 can be tightly connected to the guide bar portion 701 while avoiding interference with other components.

[0029] A cast aluminum stator 15, sleeved on the outside of the front bearing 12 and the rear bearing 13, is supported at the inner center of the mounting base 8. Insulating frames 16 and covers 17 are installed at both the front and rear ends of the cast aluminum stator 15. The insulating frames 16 provide insulation between the enameled wire and the cast aluminum stator 15, preventing short circuits. The covers 17 protect the enameled wire. The inner wall of the cast aluminum stator 15 has stepped limiting grooves that mate with the front bearing 12 and the rear bearing 13. These grooves position and limit the front bearing 12 and the rear bearing 13, preventing axial displacement during operation and further improving the stability of the fan operation.

[0030] The end cover 9 is composed of a rear end plate 901, a stepped cylinder 902, and a water-retaining ring 903, all integrally formed. The mounting base 8 is fixed to the inner side of the rear end plate 901 by bolts. The water-retaining ring 903 is fitted onto the outer side of the sealing flange 403, and a sealing gap is provided between the water-retaining ring 903 and the sealing flange 403, forming the first waterproof barrier to prevent external moisture from entering the fan. A dust cover 10 is installed on the outer side of the end cover 9, located on the rear end plate 901. The dust cover 10 uses a snap-fit ​​connection for easy disassembly and installation, and is used to prevent dust from entering. A wire mesh cover 11 is installed on the outer side of the dust cover 10, which can effectively prevent foreign objects from entering the fan without affecting gas flow.

[0031] The assembly process of the external rotor AC motor axial flow fan in this embodiment is as follows: S1: The bushing 2 is interference-fitted onto the main shaft 1, and then the convex tube 301 of the reinforcing plate 3 is welded and fixed to the bushing 2 to ensure that the reinforcing plate 3 is firmly installed; S2: Place the front bearing 12 and the rear bearing 13 on the outside of the main shaft 1 in sequence, located on the right side of the bushing 2. Then place the bearing cap 14 on the outside of the rear bearing 13 to complete the assembly of the main shaft 1, bushing 2, reinforcing plate 3, front bearing 12, rear bearing 13 and bearing cap 14. S3: The rotor guide bar 7 is made of pure aluminum material and directly cast onto the rotor core 6 to form a cast aluminum rotor; S4: Weld and fix the front end plate 401 of the rotor housing 4 to the reinforcing plate 3 to ensure a tight connection, and then press the cast aluminum rotor into the cylindrical tube 402 of the rotor housing 4 using an interference fit method. S5: Weld the rotor blades 5 to the outside of the cylindrical tube 402 of the rotor housing 4 using a full welding process to ensure a firm weld and to ensure that the installation angle of the rotor blades 5 is consistent. S6: Install the cast aluminum stator 15, insulating frame 16, and cover 17 on the outside of the front bearing 12 and the rear bearing 13. S7: Fix the mounting base 8 to the inner side of the rear end plate 901 with bolts, and then put the water baffle ring 903 of the end cover 9 on the outer side of the sealing flange 403 of the rotor housing 4 to complete the installation of the end cover 9. S8: Install the dust cover 10 on the outside of the rear end plate 901 with the clips, and then fix the mesh cover 11 on the outside of the dust cover 10 to complete the assembly of the entire fan.

[0032] The external rotor AC motor axial flow fan of this embodiment, through optimized material selection and structural design, uses pure aluminum material to directly cast the rotor core, which improves motor performance and reduces energy consumption; the rotor blades 5 and rotor housing 4 use the same iron material, which enhances welding firmness and eliminates safety hazards; the sealing flange 403 of rotor housing 4 cooperates with the water baffle ring 903 of end cover 9 to optimize the waterproof structure and extend the service life of the fan; the overall structure is reasonably designed, easy to assemble, and highly stable, and can be widely used in industrial production, civil construction and other fields.

[0033] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An outer rotor AC motor axial fan characterized by, The system includes a main shaft, bushing, reinforcing plate, rotor housing, rotor fan blades, cast aluminum rotor, mounting base, end cover, front bearing, rear bearing, bearing cap, cast aluminum stator, insulating frame, and protective cover. The main shaft is sequentially fitted with a bushing, front bearing, rear bearing, and bearing cap. A reinforcing plate and rotor housing are mounted on the outer side of the bushing. A rotor fan blade of the same material is mounted on the outer side of the rotor housing. A cast aluminum rotor, consisting of a rotor core and rotor guide bars, is mounted on the inner side of the mounting base. A cast aluminum stator, fitted around the front and rear bearings, is supported at the center of the inner side of the mounting base. Insulating frames and protective covers are mounted on the front and rear ends of the cast aluminum stator.

2. An external rotor AC motor axial fan according to claim 1, characterized in that The inner side of the rotor core is provided with several rotor slots along the circumference. The rotor slots are composed of a slot bottom, a slot shoulder and a slot opening in sequence.

3. An external rotor AC motor axial fan according to claim 2, characterized in that The rotor guide bar is a squirrel cage structure consisting of a guide bar section and end ring sections located at both ends. The shape of the guide bar section matches the shape of the rotor slot. The outer diameter of the end ring section is smaller than the outer diameter of the rotor core, and the inner diameter of the end ring section is larger than the inner diameter of the rotor core.

4. The external rotor AC motor axial flow fan according to claim 3, characterized in that, The rotor bars are made of pure aluminum and directly cast onto the rotor core.

5. The external rotor AC motor axial flow fan according to claim 4, characterized in that, The reinforcing plate is composed of a convex tube portion and a reinforcing plate portion located on its periphery, and the reinforcing plate portion has several radially reinforcing arches around the convex tube portion.

6. The external rotor AC motor axial flow fan according to claim 5, characterized in that, The rotor housing is composed of a front end plate, a cylindrical tube, and a sealing flange in sequence. The front end plate has a clearance hole at the center that mates with the bushing. The reinforcing plate is welded to the outside of the front end plate. The rotor fan blade is welded to the outside of the cylindrical tube. The cast aluminum rotor is pressed into the cylindrical tube of the rotor housing by interference fit.

7. An external rotor AC motor axial flow fan according to claim 6, characterized in that, Both the rotor blades and the rotor housing are made of iron.

8. An external rotor AC motor axial flow fan according to claim 7, characterized in that, The inner wall of the cast aluminum stator is provided with a stepped limiting groove that mates with the front bearing and the rear bearing.

9. An external rotor AC motor axial flow fan according to claim 8, characterized in that, The end cap is composed of a rear end plate, a stepped cylinder and a water-retaining ring in sequence. The mounting base is installed on the inner side of the rear end plate and the water-retaining ring is sleeved on the outer side of the sealing flange.

10. An external rotor AC motor axial flow fan according to claim 9, characterized in that, The end cap is equipped with a dust cover on the outside of the rear end plate, and a mesh cover is installed on the outside of the dust cover.

Images