Air-cooled outer rotor permanent magnet synchronous direct drive motor and conveyor

Abstract

This invention provides an air-cooled external rotor permanent magnet synchronous direct drive motor and a transmission. The motor includes a motor shaft and end covers at both ends of the motor shaft. A stator is fitted over the motor shaft and fixed to the end covers and / or the motor shaft. An external rotor roller is fitted onto the stator and rotatably mounted on the end covers. The stator has multiple through-flow first air passages, and the sidewall of the external rotor roller has multiple through-flow second air passages. Both the first and second air passages are arranged along the axial direction of the motor shaft. A cavity is provided on one side of the end cover located on the stator. The cavity communicates with the first and second air passages. Each cavity is connected to a heat exchange device through a corresponding air pipe. A fan is installed on the air pipe. The cavity, air pipe, and heat exchange device form a closed-loop air passage. The fan drives the gas flow within the closed-loop air passage, solving the problems of low heat exchange efficiency in air-cooled motors and the entry of high dust and corrosive salt spray into the motor with the heat dissipation airflow.

Description

Technical Field

[0001] This invention relates to the field of electric motor technology, and in particular to an air-cooled external rotor permanent magnet synchronous direct drive motor and a transmission. Background Technology

[0002] Traditional electric motor cooling solutions mainly rely on natural convection cooling on the casing surface or forced air cooling by external fans. Natural convection cooling is inefficient, while external fan cooling, in conveyor applications, easily generates dust, blowing dust and particulate matter onto the motor, which can easily clog the cooling airflow and adhere to the cooling fins, leading to a sharp decrease in cooling efficiency. In port environments, open or semi-open ventilation designs allow corrosive salt spray and conductive dust to easily penetrate the motor, which can not only corrode precision components and electrical connections, but also cause electrical short circuits, significantly reducing the motor's environmental reliability and protection level. Therefore, traditional electric motor cooling methods have many drawbacks in conveyor and port environments, such as low heat exchange efficiency of air-cooled motors and the problem of high dust and corrosive salt spray entering the motor with the cooling airflow. Summary of the Invention

[0003] This invention provides an air-cooled external rotor permanent magnet synchronous direct drive motor and a transmission to solve at least one of the above-mentioned technical problems.

[0004] According to one aspect of the invention, the motor includes: a motor shaft, End caps are provided at both ends of the motor shaft; The stator is sleeved on the outside of the motor shaft and fixed to the end cover and / or the motor shaft; An outer rotor drum is sleeved outside the stator and rotatably mounted on the end cover; A heat exchange device used to exchange heat with the outside atmosphere; The stator is provided with multiple through first air passages, and the side wall of the outer rotor drum is provided with multiple through second air passages. The first air passages and the second air passages are both arranged along the axial direction of the motor shaft. The end cover is provided with cavities on one side of the stator. The cavities are connected to the first air passages and the second air passages. Each cavity is connected to the heat exchange device through a corresponding air pipe. A fan is provided on the air pipe. The cavity, the air pipe, and the heat exchange device form a closed-loop air passage. The fan drives the gas to circulate in the closed-loop air passage.

[0005] In one embodiment, stator cores are spaced apart along the circumferential direction on the stator, and the gap between two adjacent stator cores is respectively connected to the first air passage.

[0006] In one embodiment, the cross-section of the first air passage along the direction perpendicular to the motor shaft axis is an arc-shaped hole, and the arc-shaped hole corresponds to multiple gaps within its arc range.

[0007] In one embodiment, a dustproof sealing ring is provided on one side of the end cap located on the outer rotor drum.

[0008] In one embodiment, the gas is an inert gas.

[0009] In one embodiment, the end cap is provided with an interface communicating with its corresponding cavity, the interface being used to inject inert gas into the closed-loop airway.

[0010] In one embodiment, permanent magnets are arranged at circumferential intervals on the outer rotor drum, and an air gap is provided between the permanent magnets and the stator core, the air gap being connected to the gap between two adjacent stator cores.

[0011] In one embodiment, the fan is provided with a housing, the housing is connected to the air pipe, and the fan axis is the same as the gas flow direction.

[0012] In one embodiment, the heat exchange device includes a cooling pipe and heat sinks fixed to the surface of the cooling pipe, and a cooling fan is provided on the heat sinks.

[0013] According to another aspect of the invention, a conveyor is provided, comprising the air-cooled external rotor permanent magnet synchronous direct drive motor, and further comprising rollers and a conveyor belt supported on the rollers, wherein the external rotor rollers contact and drive the conveyor belt.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. A wind-cooled external rotor permanent magnet synchronous direct drive motor, comprising a first air passage within the stator and a second air passage within the external rotor drum. The stator core and windings within the stator are the main heat source components, as are the permanent magnets fixed to the external rotor drum. Both the external rotor drum and the stator are fitted onto end caps at both ends. Cavities are provided inside the end caps, which are respectively connected to the ends of the first and second air passages. Heat exchange devices are then externally connected to the two cavities to form a closed-loop air passage. After a pressure difference is created between the two cavities by a fan, the airflow within the closed-loop air passage circulates. After the high-temperature gas from the first and second air passages enters the heat exchange device, it exchanges heat with the outside atmosphere. The cooled gas is then recirculated into the motor to cool down. The heat source components directly carry away heat through the airflow in the first and second air passages, improving heat exchange efficiency. This allows the motor to operate under high load and for extended periods without overheating. Furthermore, the motor's heat dissipation channel is a closed-loop air passage that does not exchange gas with the outside atmosphere, enabling the motor to be used in harsh environments such as ports and mines. This solves the problems of low heat exchange efficiency in air-cooled motors and the entry of high dust and corrosive salt spray into the motor with the heat dissipation airflow.

[0015] 2. A conveyor that uses an air-cooled external rotor permanent magnet synchronous direct drive motor as the drive motor. On the one hand, it can operate stably for a long time and can adapt to the harsh working conditions of the conveyor application. On the other hand, the external rotor roller of the motor directly drives the conveyor belt, avoiding noise, vibration and efficiency loss caused by complex transmission components, and reducing the number of vulnerable parts. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0017] Figure 1 This is a schematic diagram of the structure of the air-cooled external rotor permanent magnet synchronous direct drive motor in an embodiment of the present invention; Figure 2 This is an exploded view of an air-cooled external rotor permanent magnet synchronous direct drive motor in an embodiment of the present invention; Figure 3 This is a half-sectional view of the end of the air-cooled external rotor permanent magnet synchronous direct drive motor in an embodiment of the present invention; (the arrows in the figure indicate the airflow direction). Figure 4 This is a right view of an air-cooled external rotor permanent magnet synchronous direct drive motor in an embodiment of the present invention; Figure 5 yes Figure 4 Sectional view along CC; Figure 6This is a rotated sectional view of the stator in an embodiment of the present invention; Figure 7 yes Figure 6 A magnified view of a section at point D; Figure 8 This is a schematic diagram of the structure of the outer rotor drum in an embodiment of the present invention; Figure 9 This is a schematic diagram of airflow in the radiator in an embodiment of the present invention; Figure 10 This is a rotated sectional view of the motor in an embodiment of the present invention; Figure 11 yes Figure 10 A magnified view of a section at point E in the middle; Figure 12 This is a schematic diagram of the conveyor structure in this invention; Figure 13 This is a front view of the conveyor in this invention.

[0018] Figure label: 1. Motor; 11. First end cover; 12. Winding cable; 13. Second end cover; 14. Inner end cover; 15. Outer rotor drum; 16. Permanent magnet; 17. Stator core; 18. Stator winding; 19. Motor shaft; 110. Interface; 111. First bushing; 131. Second bushing; 132. Air inlet; 151. Slot; 171. Core gap; 2. Radiator; 21. First air pipe; 22. Exhaust fan; 23. Cooling pipe; 24. Cooling fan; 25. Heat sink; 26. Radiator base; 27. Second air pipe; 3. Conveyor; 31. Drag roller; 32. Lower idler roller; 33. Intermediate frame; 34. Base frame; 35. Idling roller; 36. Baffle plate; 37. Conveyor belt; 38. Shaft support; 4. Stator; 41. Air outlet; 42. First air passage; 43. Second air passage; 44. Stator winding cable connection hole.

[0019] 5. First bearing; 6. Second bearing; 7. Sealing ring. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product is in use. These are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., appearing in the description of this invention are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0024] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of this invention does not imply that the components are required to be absolutely horizontal or suspended, but rather that they may be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it may be slightly tilted.

[0025] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] Example 1 An existing air-cooled external rotor permanent magnet direct drive synchronous belt transmission drum motor includes a motor shaft and a stator support sleeved on the outside of the motor shaft. Through the arrangement of the motor shaft, stator support, stator, rotor, fixing parts and motor end cover, the motor directly acts as a drum, which improves the motor efficiency. With the cooperation of an inlet fan and an exhaust fan, ventilation holes are provided in the motor shaft. The ventilation holes are equipped with staggered air guide plates to facilitate the dispersion of the blown air force, increase the heat dissipation capacity, and allow the air to carry away the heat through the entire motor interior.

[0027] In the above-mentioned motor cooling scheme, the air guide plate inside the motor shaft is placed horizontally along the vertical axis. On the one hand, this will slow down the gas flow rate. On the other hand, the gas channel only passes through the inside of the motor shaft. Even if the air guide plate is installed, the main heat-generating parts of the motor, such as the stator coil, cannot directly exchange heat through the gas, thus limiting the cooling efficiency. Furthermore, the power source of the cooling airflow directly blows air into the motor shaft. In an atmospheric environment with a lot of dust and high corrosiveness, this can easily cause problems such as internal corrosion of the motor shaft and dust accumulation and blockage of the air guide plate.

[0028] An existing forced internal ventilation asynchronous motor and ventilation method include a lower fan that draws in airflow from the air inlet of the rear end cover of the asynchronous motor and blows it out. The airflow blown out by the lower fan is divided into an external flow and an internal flow. The external flow is blown into the ventilation channel between the stator and the motor housing, and the ventilation channel leads the airflow to the air outlet and blows it out. The internal flow is blown into the gap between the rotor and the stator by an upper fan that draws in the internal flow from the gap between the rotor and the stator and blows it toward the front end cover of the asynchronous motor. The front end cover leads the airflow to the air outlet and blows it out. The air outlet is formed at the gap between the cavity on the top wall of the front end cover and the outer wall of the motor housing. The airflow blown out of the air outlet is blown vertically along the outer wall of the motor housing.

[0029] In the above-mentioned motor cooling scheme, the gas passes through the gap between the rotor and the stator, which is also prone to internal corrosion and dust accumulation. On the one hand, during the relative rotation of the rotor and the stator, the gap between them, as a gas channel, is easily disturbed by both sides, which reduces the airflow speed. In turn, the airflow increases the aerodynamic resistance of the rotor. The wind resistance loss reduces the motor output power and aggravates heat generation. On the other hand, both the upper and lower fans rely on the rotation of the motor shaft to provide power, which also reduces their output power.

[0030] like Figure 1 and Figure 2As shown, according to one aspect of the present invention, a wind-cooled external rotor permanent magnet synchronous direct drive motor is provided, including a motor 1 and a radiator 2. The radiator 2 is connected to both ends of the motor 1 along the axial direction by air pipes to form a closed-loop air passage that can be circulated. The radiator 2 includes a heat exchange device for exchanging heat with the outside atmosphere, and a fan for driving airflow through the heat exchange device and the circulating air passage. In this embodiment, the fan is a ventilation fan 22. The ventilation fan 22 drives the airflow to enter from one end of the motor 1, exit from the other end and carry away the heat inside the motor 1, and enter the heat exchange device to exchange heat.

[0031] Furthermore, such as Figures 1-5 As shown, motor 1 is an external rotor permanent magnet synchronous direct drive motor. The internal airflow direction is along the axis of motor 1 from end B to end A. Motor 1 includes a first end cover 11 located at end A and a second end cover 13 located at end B. The first end cover 11 and the second end cover 13 are coaxial, and both have end cover holes along the axis AB. The motor shaft 19 passes through the end cover holes and is fixed to them. The motor shaft 19 and the end cover holes are interference-fitted. Here, the side of the first end cover 11 and the second end cover 13 closest to the center of motor 1 along the axis is defined as the inner side, and the other side as the outer side. The inner sides of both the first end cover 11 and the second end cover 13 have concave cavities. The side surface surrounding the axis AB in the cavity is an inner cylindrical surface. Further, the first end cover 11... One end cap 11 and the second end cap 13 extend inward along the axis AB around the end cap hole to form a tubular structure. This structure is a bushing, which is sleeved and fixed around the motor shaft 19. The cavity is arranged around the bushing. The stator 4 is fixed on the outer circumference of the bushing. The first bushing 111 is located on the first end cap 11, and the second bushing 131 is located on the second end cap 13. The stator 4 is nested and fixed on the outer walls of the first bushing 111 and the second bushing 131. The stator 4 has a tubular structure. The two ends of its inner wall are respectively interference-fitted with the first bushing 111 and the second bushing 131. Multiple stator cores 17 are evenly distributed along the outer circumference of the stator 4. The stator windings 18 are evenly wound on the stator cores 17.

[0032] Furthermore, one end of the motor shaft 19 passes through the first bushing 111 and the end cap hole of the first end cap 11 in sequence, and the other end passes through the second bushing 131 and the end cap hole of the second end cap 13 in sequence, thereby assembling the motor shaft 19, the two end caps and the stator 4. The assembled structure is fixed during the operation of the motor 1.

[0033] Furthermore, a winding cable 12 is provided on the first end cover 11. The winding cable 12 passes through the first end cover 11 and enters its interior. A stator winding cable connection hole 44 is provided on the stator 4. The winding cable 12 passes through the stator winding cable connection hole 44 and is electrically connected to the stator winding 18, so that the stator winding 18 generates an alternating magnetic field. The winding cable 12 is externally connected to a control device. The winding cable 12 contains three wires, which pass three-phase current to the stator winding 18 to realize excitation and speed regulation control.

[0034] Furthermore, such as Figures 1-5 The outer rotor portion of the motor 1 shown includes an outer rotor drum 15 and permanent magnets 16. The outer rotor drum 15 is a cylindrical structure open at both ends. Bearings are arranged around the inner edges of the first end cover 11 and the second end cover 13 around the axis AB. The outer wall of the outer rotor drum 15 is supported and fitted onto the bearings, allowing it to rotate around the motor shaft 19 along the inner cylindrical surface of the cavities of the first end cover 11 and the second end cover 13. Permanent magnets 16 are arranged circumferentially on the inner wall of the outer rotor drum 15. An axially arranged slot 151 is provided, and permanent magnets 16 are arranged in a strip shape and parallel to each other in the slot 151. This arrangement increases the contact area between the permanent magnets 16 and the outer rotor drum 15. The permanent magnets 16 are heat source components, which can more efficiently conduct heat to the second air passage 43 in the side wall of the outer rotor drum 15. After the winding cable 12 is energized, the permanent magnets 16 generate an alternating magnetic field coupling with it, thereby driving the outer rotor drum 15 to rotate. The outer rotor drum 15 can be directly used as a driving component to realize torque output.

[0035] Furthermore, both ends of the outer rotor and stator 4 are located within the cavities of the end caps.

[0036] Furthermore, such as Figure 6 and Figure 7 As shown, first air passages 42 are provided at both ends of the stator 4. Multiple first air passages 42 are arranged circumferentially along the axis AB. There are core gaps 171 between the stator cores 17. Preferably, the first air passages 42 can be arranged in two ways: one is that the number and position of the first air passages 42 correspond to the core gaps 171; the other is that the first air passages 42 are set as arc-shaped holes, with the arc covering multiple core gaps 171. This arrangement ensures that when the airflow passes sequentially through the first air passages 42 at one end of the stator 4, the core gaps 171, and the first air passages 42 at the other end, the entire path is nearly straight, reducing the impact of the path on the airflow velocity and achieving efficient heat exchange. Furthermore, as... Figure 7 In the enlarged view D shown, the stator winding 18 is wound around the root of each stator core 17. The stator winding 18 and the stator core 17 are the main heat source components of the motor. When the airflow passes through the core gap 171, it directly contacts the outer surface of both and carries away the heat. Then it is discharged from the first air passage 42 located at the A end of the stator 4 and enters the interior of the first end cover 11.

[0037] Furthermore, after the permanent magnet 16 is installed on the outer rotor drum 15, there is an air gap between the side of the permanent magnet 16 near the axis AB and the stator core 17 on the stator 4. This ensures that the outer rotor drum 15 will not wear against the stator core 17 during rotation. This air gap is connected to the core gap 171. When the airflow passes through the core gap 171, Furthermore, such as Figure 8As shown, multiple second air passages 43 are arranged in the side wall of the outer rotor drum 15 along the axial direction AB. The second air passages 43 are evenly distributed circumferentially on the side wall of the outer rotor drum 15. The cross-section of the second air passage 43 is arc-shaped. The permanent magnet 16 is attached to the inner wall of the outer rotor drum 15. The permanent magnet 16 generates heat due to eddy current loss during motor operation and is one of the main heat source components. At this time, the airflow passes through the side wall of the outer rotor drum 15 and is separated from the permanent magnet 16 by only a thin layer, which can quickly remove the heat. Moreover, the heat generated by the outer rotor drum 15 when outputting power and, for example, the rolling friction of the conveyor belt, can also be exchanged through the second air passages 43. Finally, the airflow in the second air passages 43 flows axially from end B to end A and enters the interior of the first end cover 11.

[0038] Furthermore, such as Figure 1 and Figure 3 As shown, the airflow in the first air passage 42 and the second air passage 43 converges to the inner side of the first end cover 11, that is, the side close to the center along the axial direction, and then exits through the air outlet 41 provided on the first end cover 11. The air outlet 41 is connected to the radiator 2. After the airflow enters the radiator 2 and dissipates the heat to the outside, it enters the inner side of the second end cover 13 through the air inlet 132 provided on the second end cover 13 under the drive of the ventilation fan 22, and returns to the B end of the first air passage 42 and the second air passage 43 to complete one heat exchange cycle.

[0039] Preferably, the outer rotor drum 15 is made of a metal alloy material with high magnetic permeability, such as iron-aluminum alloy and iron-nickel alloy, thereby optimizing the magnetic circuit. The array of permanent magnets 16 fixed inside it is preferably made of high-performance rare earth permanent magnet material such as neodymium iron boron to provide a stronger excitation magnetic field. The stator winding 18 is made of high-purity, high-conductivity copper wire to reduce resistance loss. The stator core 17 is made of multiple layers of thin silicon steel sheets stacked axially, with an insulating layer between the silicon steel sheets to suppress eddy current loss.

[0040] Preferably, the ventilation fan 22 can be replaced by other equipment with the function of driving gas, such as axial flow fan, compressor and gas booster pump.

[0041] The motor air-cooling scheme adopted in this embodiment connects the radiator 2, cooling fan 24, and both ends and the interior of the motor 1 in series to form a closed-loop airflow channel. This prevents external air from entering the motor 1 and causing damage in highly corrosive or dusty environments. A first airflow channel 42 is set inside the motor 1 for cooling the stator 4, and a second airflow channel 43 is set for cooling the outer rotor drum 15. The first airflow channel 42 is directly connected to both ends of the iron core gap 171, and the airflow passes directly from the heat periphery of the stator iron core 17 and stator winding 18 to achieve heat exchange and cooling of the stator 4. The second airflow channel 43 passes through the side wall of the outer rotor drum 15, and the airflow exchanges heat with the permanent magnet 16 installed on the inner wall of the outer rotor drum 15. The two exchange heat through the outer rotor drum 15, which is made of metal alloy material, to achieve heat exchange and cooling of the motor rotor. Both the first airflow channel 42 and the second airflow channel 43 directly target the main heat source components inside the motor 1 for heat exchange, thus improving the heat dissipation efficiency.

[0042] Example 2 like Figure 1 and Figure 2 As shown, the radiator 2 in Embodiment 1 includes a first air pipe 21, an exhaust fan 22, a cooling pipe 23, and a second air pipe 27 connected in sequence. This connection structure, together with the first air passage 42 and the second air passage 43 inside the motor 1, forms a recirculating closed-loop air passage. The first air pipe 21 is connected to the air outlet 41 on the first end cover 11 to guide the airflow from the motor 1 to the cooling pipe 23. The second air pipe 27 is connected to the air inlet 132 provided on the second end cover 13 to guide the airflow through the cooling pipe 23 into the motor 1.

[0043] Furthermore, the ventilation fan 22 is housed inside a housing and driven by an external power source. This housing is connected between the first air pipe 21 and the cooling pipe 23, or between the second air pipe 27 and the cooling pipe 23, or both of the above positions are used to install the ventilation fan 22. The axial direction of the ventilation fan 22 is coaxial with the first air pipe 21 or the second air pipe 27 at its actual installation position, that is, the axial direction of the ventilation fan 22 is the same as the airflow direction, so as to drive the airflow with maximum efficiency. The function of the ventilation fan 22 is to create an air pressure difference before and after it.

[0044] Specifically, in the aforementioned recirculating closed-loop air passage, the ventilation fan 22 can create an air pressure difference between end A and end B inside the motor 1, thereby driving the airflow to flow from end B to end A within the first air passage 42 and the second air passage 43, and sending the high-temperature gas inside the motor 1 into the cooling pipe 23.

[0045] Furthermore, such as Figure 9As shown, the cooling pipe 23 is part of a heat exchange device in one embodiment. The heat exchange device also includes a cooling fan 24, heat sink 25, and a radiator base 26. The cooling pipe 23 is fixed on the radiator base 26. The surface of the cooling pipe 23 is arrayed with heat sink 25, which are in direct contact with the cooling pipe 23. The heat sink 25 adopts a finned or needle-shaped equal-height surface area structure, which greatly enhances the heat conduction efficiency by significantly increasing the contact area with the external cooling air, thereby achieving efficient heat dissipation within the limited installation space of the whole machine. The radiator base 26 is fixedly installed on the ground or other support structure outside the motor 1. Furthermore, the cooling fan 24 is fixed on the heat sink 25. When the cooling fan 24 is started by an external power supply, it can accelerate the passage of external air around the heat sink 25 and improve the heat exchange efficiency.

[0046] Preferably, the cooling pipe 23 is made of a metal material with high thermal conductivity such as copper or aluminum alloy, and can be designed as a coil or serpentine structure to maximize its heat exchange surface area with the air flowing inside; the cooling pipe 23 can be configured as multiple branches in parallel, each branch is equipped with a heat sink 25 and a cooling fan 24, and the heat exchange efficiency between the radiator 2 and the outside air; the cooling pipe 23 can also use water cooling to exchange heat with the outside.

[0047] Example 3 like Figure 10 and Figure 11 As shown, based on Embodiment 1 or Embodiment 2, an inner end cover 14 is screwed and fixed to the inner side of the first end cover 11 and the second end cover 13 along the axis AB. The inner end cover 14 has an annular structure. An annular sealing cavity is provided on the inner wall of the inner end cover 14, that is, on the side close to the outer rotor drum 15. A sealing ring 7 is fitted on the outer wall of the outer rotor drum 15. The two are interference fit. The sealing ring 7 is located in the sealing cavity and rotates with the outer rotor drum 15. It is used to prevent high dust and corrosive salt spray air in the external environment from entering the motor 1 through the gap between the outer rotor drum 15 and the two end covers, so as to keep the inside of the motor 1 clean.

[0048] Preferably, the sealing ring 7 is made of an elastomer material, such as nitrile rubber, fluororubber or hydrogenated nitrile rubber, which has good high temperature resistance and anti-aging properties.

[0049] Furthermore, two bearings are provided on the inner walls of the first end cover 11 and the second end cover 13, including a first bearing 5 and a second bearing 6. The two bearings are used to support the rotation of the outer rotor drum 15. The first bearing 5 and the second bearing 6 are alternately arranged along the axis AB towards the center. The second bearing 6 is located on the end face of both end covers, which is convenient for installation or for lubrication after the inner end cover 14 is removed.

[0050] Example 4 like Figure 1As shown, interfaces 110 are provided on both the first end cover 11 and the second end cover 13. Both interfaces 110 are connected to the inside of the motor 1. After assembling the entire motor 1 and the radiator 2, the two interfaces 110 are opened, and an inert gas, such as nitrogen, is injected into the recirculating closed-loop air passage and the motor 1 through one of the external conduits. After the other interface 110 continues to emit airflow for a period of time, both interfaces 110 are sealed with sealing plugs. Using inert gas to circulate heat exchange can delay the corrosion of heat source components by airflow.

[0051] Example 5 For ease of installation, both the first air pipe 21 and the second air pipe 27 are equipped with pipe connectors at the ends that connect to the end cap. The air outlet 41 and the air inlet 132 corresponding to the pipe connectors are provided with internal threads. The first air pipe 21 is screwed to the air outlet 41 through the pipe connector, and the second air pipe 27 is screwed to the air inlet 132 through the pipe connector, so as to realize the quick assembly of the radiator 2 and the motor 1. The use of pipe connectors can also ensure the airtightness of the air outlet 41 and the air inlet 132.

[0052] According to another aspect of the invention, such as Figure 12 and Figure 13 As shown, an air-cooled external rotor permanent magnet synchronous direct drive motor and a conveyor are provided. The conveyor uses the air-cooled external rotor permanent magnet synchronous direct drive motors described in Embodiments 1 to 5 as a power source. The conveyor includes: The steel structure frame adopts a steel profile structure, including a base frame 34 and an intermediate frame 33. The base frame 34 serves as the support for the entire belt conveyor and the basic component for the installation of various mechanisms. The intermediate frame 33 is welded to the base frame 34 by steel structure supports on the left and right sides. A pair of baffle plates 36 are provided at both ends of the intermediate frame 33. The baffle plates 36 are vertically fixed on both sides of the ends of the intermediate frame 33 to prevent materials from slipping when loading and unloading at the beginning and end.

[0053] Furthermore, the first end of the intermediate frame 33 is equipped with an air-cooled external rotor permanent magnet synchronous direct drive motor, and the tail end is equipped with a redirecting roller 35. Each pair of baffle plates 36 is equipped with a shaft support 38 facing each other. The pair of shaft supports 38 at the first end is used to fix the two ends of the motor shaft 19 in the motor 1. The pair of shaft supports 38 at the tail end are equipped with bearings to support the redirecting roller 35. The redirecting roller 35 adopts the same specification as the motor shaft 19.

[0054] Preferably, the baffle plate 36 is provided with strip-shaped holes along the length of the intermediate frame 33, and the two shaft supports 38 can slide along the corresponding strip-shaped holes. After the shaft supports 38 are adjusted and fixed, the installation positions of the motor shaft 19 and the motor 1 are adjusted, so that the conveyor belt 37 is tensioned on the outer rotor drum 15, increasing the friction.

[0055] Furthermore, a pair of drag rollers 31 are arranged on the intermediate frame 33 along the width direction, and multiple pairs of drag rollers 31 are installed at intervals along the length direction of the intermediate frame 33. The conveyor belt 37 is in the shape of a ring, with one end fitted onto the outer rotor drum 15 and the other end fitted onto the redirecting drum 35. The conveyor belt 37 forms a double-layered, tight loop around the above structure. Its upper layer is laid on the drag rollers 31, and its lower layer passes through the bottom of the intermediate frame 33. Similarly, lower support rollers 32 are arranged at intervals along the length direction at the bottom of the intermediate frame 33. Both the drag rollers 31 and the lower support rollers 32 can reduce the friction on the conveyor belt 37 and play a supporting and guiding role for the conveyor belt 37.

[0056] Furthermore, when installing an air-cooled external rotor permanent magnet synchronous direct drive motor, the radiator 2 is located below the motor 1, and the radiator base 26 is installed on the base frame 34 or the ground, which does not occupy space and will not collide with the conveyed goods.

[0057] The operating principle of this conveyor is as follows: The conveyor belt 37 is in close contact with part of the surface of the outer rotor drum 15. Driven by the motor 1, the outer rotor drum 15 drives the conveyor belt 37 to rotate. The conveyor belt 37 starts from the beginning, goes along the drag roller 31 to the redirecting drum 35, then rotates around the redirecting drum 35 and changes direction to reach the bottom of the intermediate frame 33. Then it goes back to the outer rotor drum 15 from the bottom of the intermediate frame 33 along the lower support roller 32, realizing cyclic conveying.

[0058] The air-cooled external rotor permanent magnet synchronous direct drive motor is applied to the conveyor. The external rotor drum 15 is used directly as the drive drum of the conveyor, which directly contacts the conveyor belt 37 and provides driving force. This eliminates intermediate mechanical transmission components such as reducers and couplings in the traditional transmission system, realizing the simplification of structure and direct drive with low speed and high torque. During long-term, high-power output, the air-cooled external rotor permanent magnet synchronous direct drive motor achieves efficient heat dissipation through the internal circulating air passage and radiator 2. At the same time, this motor has good sealing performance and can be used in the high salt spray corrosive air and dusty environment of the harbor.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wind-cooled external rotor permanent magnet synchronous direct drive motor, characterized in that, include: Motor shaft (19). End caps are provided at both ends of the motor shaft (19); The stator (4) is sleeved on the motor shaft (19) and fixed to the end cover and / or the motor shaft (19); The outer rotor drum (15) is sleeved outside the stator (4) and rotatably mounted on the end cover; A heat exchange device used to exchange heat with the outside atmosphere; The stator (4) is provided with multiple through first air passages (42), and the side wall of the outer rotor drum (15) is provided with multiple through second air passages (43). The first air passages (42) and the second air passages (43) are both arranged along the axial direction of the motor shaft (19). The end cover is provided with cavities on one side of the stator (4). The cavities are connected to the first air passages (42) and the second air passages (43). Each cavity is connected to the heat exchange device through a corresponding air pipe. A fan is provided on the air pipe. The cavity, the air pipe, and the heat exchange device form a closed-loop air passage. The fan drives the gas to circulate in the closed-loop air passage.

2. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 1, characterized in that, The stator (4) is provided with stator cores (17) spaced apart along the circumference, and the gap between two adjacent stator cores (17) is connected to the first air passage (42).

3. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 2, characterized in that, The first air passage (42) has an arc-shaped hole in cross section along the axis perpendicular to the motor shaft (19), and the arc-shaped hole corresponds to multiple gaps within its arc range.

4. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 1, characterized in that, A dustproof sealing ring (7) is provided on one side of the outer rotor drum (15) on the end cover.

5. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 1, characterized in that, The gas is an inert gas.

6. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 5, characterized in that, The end cap is provided with an interface (110) that connects to its corresponding cavity, and the interface (110) is used to inject inert gas into the closed-loop airway.

7. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 1, characterized in that, Permanent magnets (16) are arranged circumferentially on the outer rotor drum (15). An air gap is provided between the permanent magnets (16) and the stator core (17). The air gap is connected to the gap between two adjacent stator cores (17).

8. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 1, characterized in that, The fan is provided with a casing, which is connected to the air pipe, and the fan axis is the same as the gas flow direction.

9. The air-cooled external rotor permanent magnet synchronous direct drive motor according to claim 1, wherein the heat exchange device includes a cooling pipe (23) and a heat sink (25) fixed on the surface of the cooling pipe (23), and a cooling fan (24) is provided on the heat sink (25).

10. A conveyor comprising the air-cooled external rotor permanent magnet synchronous direct drive motor according to any one of claims 1 to 9, characterized in that, It also includes rollers and a conveyor belt (37) supported on the rollers, the outer rotor drum (15) contacting and driving the conveyor belt (37).

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