Explosion-proof high-efficiency air-cooled electric drum and mining explosion-proof equipment equipped with the drum

Abstract

This invention relates to the field of electric drums, and discloses an explosion-proof, high-efficiency air-cooled electric drum and explosion-proof mining equipment equipped with the drum, including an electric drum body, an air-cooling assembly, an external heat exchange assembly, and an internal air-cooling assembly. The air-cooling assembly uses a motor to drive external fan blades, introducing cooling airflow into an air-cooling channel that runs through the central shaft to directly cool the internal stator. The external heat exchange assembly consists of longitudinal and transverse heat dissipation fins on the surface of the explosion-proof shell, enhancing external heat dissipation. An internal fan driven by a gear ring and internal gear is provided to agitate the internal air; simultaneously, a side air pipe guides part of the airflow to push the pneumatic plate of the internal air-cooling assembly, causing the piston rod to reciprocate within the telescopic cylinder, forming a "breathing" heat exchange. This invention achieves highly efficient multi-stage heat dissipation through the synergistic effect of axial air cooling, enhanced external heat dissipation, forced internal circulation, and active pumping heat exchange, significantly reducing operating temperature, and is particularly suitable for harsh environments such as mines where flammable and explosive materials are present.

Description

Technical Field

[0001] This invention relates to the field of electric drums, specifically to an explosion-proof, high-efficiency air-cooled electric drum and explosion-proof mining equipment equipped with the drum. Background Technology

[0002] Electric roller conveyors, which integrate a motor and reduction gear mechanism within the roller, are widely used in industrial sectors such as mining, ports, and power plants due to their compact structure, good sealing, and convenient installation. In these applications, especially in underground environments like coal mines and metal mines, where the air often contains flammable and explosive substances such as methane and coal dust, extremely high requirements are placed on the explosion-proof performance of electrical equipment. Therefore, explosion-proof electric roller conveyors have become crucial equipment in these application scenarios.

[0003] The core of an explosion-proof electric drum motor lies in its explosion-proof enclosure design. This enclosure can withstand potential internal arcing or spark explosions and prevent the flames from spreading outside, thus avoiding ignition of the surrounding explosive gas environment. However, this sealed structure also presents a significant challenge—heat dissipation. During operation, the motor (stator and rotor) generates a large amount of heat due to electromagnetic losses, iron losses, and mechanical friction. Under normal conditions, this heat can be dissipated through natural convection and radiation on the enclosure surface or through forced cooling by an external fan. However, inside the explosion-proof enclosure, due to the confined space, air cannot directly convect with the outside. Heat can only be conducted to the outside through the enclosure and then dissipated. This long heat dissipation path and high thermal resistance lead to heat accumulation and a rapid increase in internal temperature.

[0004] Excessive operating temperature can cause a series of problems: First, it accelerates the aging of the stator coil insulation material, shortens the motor's lifespan, and may even cause insulation breakdown, resulting in internal short circuits and arcing. Despite the protection of the explosion-proof enclosure, the equipment itself will be damaged, leading to downtime. Second, high temperatures can affect the magnetic properties of permanent magnets (if a permanent magnet synchronous motor is used), causing irreversible demagnetization, leading to decreased motor efficiency and torque fluctuations. Third, bearing grease will fail at high temperatures, accelerating wear and causing premature damage. Therefore, heat dissipation capacity directly determines the power density, reliability, and service life of explosion-proof electric drum motors.

[0005] Existing explosion-proof electric drum cooling technologies have the following limitations: Early or low-power devices mainly relied on increasing the surface area of ​​the outer casing (such as by adding heat dissipation fins) to enhance natural heat dissipation. This method is inefficient and severely limits the power increase of the drum. Later, forced air cooling methods were developed by adding an external fan to blow air onto the outer casing. Although this improved the situation, the cooling airflow only came into contact with the outside of the casing. Heat still needed to be conducted from the high-temperature components inside through the solid casing to the outside. The overall heat dissipation efficiency was still limited by the thermal conductivity of the casing. For high-power-density motors, the cooling effect was still not ideal. Some designs attempted to use the rotation of the drum to agitate the internal air and create natural convection. However, in the narrow air gap between the sealed, stationary stator and the rotating casing, the airflow was slow, the heat exchange effect was limited, and local overheating areas were easily formed, especially at the end of the stator winding in the center, where heat was difficult to transfer effectively to the casing. Some attempts to improve internal heat dissipation, such as adding an internal fan or circulating oil circuit, often resulted in an extremely complex structure. The internal fan operates in the explosion-proof cavity, which places extremely high demands on its materials and reliability, and also increases the potential for failure. While oil cooling systems offer high heat exchange efficiency, they pose a risk of leaks. Leaks can cause oil contamination, potentially disrupting equipment operation. Furthermore, in environments with explosion-proof requirements, such as coal mines, the leaked oil itself presents a safety hazard. Additionally, system costs and maintenance requirements increase significantly. Dust-rich environments like mines cause traditional external heat sinks to accumulate dust, forming an insulating layer and severely impacting heat dissipation. Complex oil or water cooling systems require high levels of cleanliness and maintenance, making them unsuitable for harsh mining conditions.

[0006] Therefore, there is an urgent need in this field for a novel explosion-proof electric roller cooling solution. It needs to overcome the bottlenecks of traditional cooling methods while ensuring strict explosion-proof performance, achieving efficient, multi-path synergistic heat dissipation. An ideal design should actively and rapidly remove internally generated heat, while simultaneously enhancing heat exchange between the outer casing and the external environment. Furthermore, the structure should be relatively simple and reliable, suitable for long-term stable operation in dusty and harsh industrial environments. Summary of the Invention

[0007] This invention aims to overcome the technical bottlenecks faced by existing explosion-proof electric drum motors, such as low heat dissipation efficiency, easy internal overheating, complex structure, and poor environmental adaptability. Specifically, existing technologies mainly rely on natural heat dissipation from the outer shell or external air cooling. Heat must be conducted through the outer shell, resulting in a long path and high thermal resistance, making it difficult to meet the heat dissipation requirements of high-power-density motors. Internal air convection is slow, easily forming local hot spots. Complex liquid cooling systems also pose leakage risks and are unsuitable for harsh operating conditions. Therefore, this invention provides an explosion-proof, high-efficiency air-cooled electric drum motor. Its purpose is to construct a multi-layered, combined active and passive, internal and external synergistic composite air cooling system to achieve efficient and uniform heat dissipation of the electric drum's interior and outer shell while ensuring strict explosion-proof performance. This significantly reduces operating temperature, improves equipment power density, reliability, and service life, and is particularly suitable for harsh environments such as mines with flammable, explosive, and dusty conditions.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an explosion-proof high-efficiency air-cooled electric drum, comprising an electric drum body, an air-cooling component, a driver, and an external heat exchange component.

[0009] The electric drum body includes an explosion-proof housing serving as the rotor. Both ends of the explosion-proof housing are supported on bearing seats via bearing sleeves, and bearings are installed inside the bearing sleeves. Several permanent magnets are uniformly fixed to the inner wall of the explosion-proof housing. A stator assembly is fixedly installed at its center. This stator assembly includes a stator core and stator coils wound around it. A central shaft, which is hollow and forms an internal air-cooling channel, passes through the center of the stator core.

[0010] The air-cooled assembly is installed on one side of the electric drum body and includes an air-cooled side frame, a motor fixed inside the air-cooled side frame, an outer fan blade driven by the motor, and a filter screen located at the air inlet. The air-cooled side frame is connected to the bearing sleeve of the electric drum body via a flange, so that one end of the air-cooled channel inside the air-cooled side frame is connected to the air-cooled channel inside the central shaft, and the other end of the air-cooled channel is connected to the air outlet located on the other side of the electric drum body, forming an axial cooling air duct that runs through the center of the stator area.

[0011] The driver is installed on the other side of the electric drum body relative to the air-cooling assembly, and is used to power the stator coils and control the operation of the electric drum.

[0012] The external heat exchange assembly includes several external heat dissipation longitudinal fins uniformly surrounding and fixed to the outer surface of the explosion-proof housing, and several external heat dissipation transverse fins connected to these external heat dissipation longitudinal fins, which together form a grid-like structure that increases the heat dissipation area.

[0013] One of the core improvements of this invention is that the air-cooling assembly is also connected to several side air pipes. One end of these side air pipes communicates with the interior of the air-cooling side frame, while the other end extends and its outlet is located in the area between adjacent external heat dissipation fins. When the motorized drum is running, the airflow ejected from the side air pipes interacts with the rotating external heat exchange assembly, aiming to disturb the airflow and enhance heat dissipation.

[0014] The second core improvement of this invention lies in the inclusion of an internal air circulation promotion structure. A gear ring is fixedly installed on the inner wall of one end of the explosion-proof housing. Correspondingly, an internal fan is provided, which includes a gear mounting rod fixed to the end face of the stator core. An internal gear and an internal fan blade coaxially connected to the internal gear are rotatably mounted on the gear mounting rod via bearings or sleeves. The internal gear meshes with the fixed gear ring. When the explosion-proof housing rotates as a rotor, it drives the gear ring to rotate, thereby driving the internal gear and its internal fan blades to rotate, agitating the air inside the explosion-proof housing and forming a forced internal circulation.

[0015] The third core improvement of this invention lies in the addition of a unique internal air-cooling assembly. This internal air-cooling assembly includes several telescopic cylinders uniformly arranged around the end face of the explosion-proof housing. One end of each telescopic cylinder is connected to the interior of the explosion-proof housing, and the other end houses a telescopic piston rod. A pneumatic plate is fixedly connected to the end of the piston rod located outside the explosion-proof housing, and the pneumatic plate is positioned between adjacent external heat dissipation fins. A return spring is connected between the pneumatic plate and a fixed block fixed to the outer surface of the explosion-proof housing. Its working mechanism is as follows: the airflow ejected from the side air pipe acts on the pneumatic plate, pushing the piston rod to overcome the elastic force of the return spring and be pulled out of the telescopic cylinder, drawing hot air from inside the explosion-proof housing into the telescopic cylinder; when the airflow changes or the return spring exerts force, the piston rod returns to its original position, pumping the air in the telescopic cylinder, which has been cooled to a certain extent, back into the explosion-proof housing. This reciprocating motion achieves active exchange and auxiliary cooling of the internal air.

[0016] Furthermore, the inner wall of the air-cooling channel of the central shaft is integrally provided with several internal heat dissipation fins to increase the internal heat dissipation area.

[0017] Furthermore, a bearing sealing plate is provided on the bearing end face inside the bearing sleeve to improve sealing reliability.

[0018] A type of explosion-proof mining equipment, equipped with an explosion-proof, high-efficiency air-cooled electric drum.

[0019] Compared with the prior art, the present invention provides an explosion-proof high-efficiency air-cooled electric drum and mining explosion-proof equipment equipped with the drum, which has the following beneficial effects:

[0020] 1. This invention breaks through the limitations of a single heat dissipation mode, creatively integrating axial direct air cooling, shell forced air cooling with vortex-enhanced heat dissipation, forced internal air circulation, and active internal air pumping heat exchange. This composite system achieves direct cooling of the main heat source, efficient heat dissipation of the shell, and enhanced disturbance and exchange of airflow in the internal enclosed space, forming a highly efficient heat dissipation network that works from the inside out.

[0021] 2. By incorporating an internal fan, the rotational power of the drum drives the internal fan blades, effectively breaking the static or slow convection of the internal air. This promotes uniform flow of hot air, preventing the formation of localized hot spots and significantly improving cooling conditions in traditionally neglected areas such as the stator ends. Combined with the "breathing" pumping action of the internal air-cooling components, this not only accelerates heat exchange between the internal air and the inner wall of the outer casing but also enables additional heat exchange between some of the internal hot air and the cylinder wall through the telescopic cylinder. This further reduces the temperature of the returning air, achieving a degree of "internal circulation cooling," which is difficult to achieve with traditional structures.

[0022] 3. The external heat exchange components themselves generate a certain degree of forced convection due to the rotation of the drum. The side air ducts precisely guide a portion of the cooling airflow into the gaps between the heat sink fins, inducing vortices through design, effectively disrupting the thermal boundary layer on the surface of the heat sink fins and greatly enhancing the convective heat transfer coefficient. At the same time, this continuous airflow also helps to blow away dust accumulated between the heat sink fins, exhibiting a certain degree of self-cleaning effect, adapting to dusty environments such as mines, and maintaining long-term heat dissipation performance.

[0023] 4. The entire cooling system cleverly utilizes existing structures or shared power sources, eliminating the need for complex hydraulic or water cooling systems and avoiding leakage risks. All improvements are implemented within explosion-proof requirements, and the internal air-cooling components and other structural designs are ingenious and reliable. The system structure is relatively simple, easy to maintain, and highly suitable for long-term stable operation in harsh industrial environments. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the isometric three-dimensional structure of the present invention;

[0025] Figure 2 This is a rear-view three-dimensional structural diagram of the present invention;

[0026] Figure 3 This is a schematic diagram of the installation structure of the external heat exchange component of the present invention;

[0027] Figure 4 This is a schematic diagram of the electric drum stator structure of the present invention;

[0028] Figure 5 This is a schematic diagram of the bearing mounting structure of the present invention;

[0029] Figure 6 This is a schematic diagram of the air-cooled component structure of the present invention;

[0030] Figure 7 This is a schematic diagram of the connection structure between the bearing sleeve and the air-cooled side frame of the present invention;

[0031] Figure 8 This is a schematic diagram of the air-cooled channel structure of the present invention;

[0032] Figure 9 This is a schematic diagram of the internal fan mounting structure of the present invention;

[0033] Figure 10 This is a schematic diagram of the three-dimensional structure of the internal fan of the present invention;

[0034] Figure 11 This is a schematic diagram of the internal air-cooling component structure of the present invention.

[0035] In the diagram: 1. Bearing housing; 2. Electric roller; 3. Explosion-proof housing; 4. Air-cooled assembly; 5. Air outlet; 6. Driver; 7. External heat dissipation fins; 8. External heat dissipation fins; 9. External heat exchange assembly; 10. Side air pipe; 11. Stator core; 12. Stator coil; 13. Central shaft; 14. Internal heat dissipation fins; 15. Bearing; 16. External fan blades; 17. Motor; 18. Filter screen; 19. End plate; 20. Bearing sleeve; 21. Air-cooled side frame; 22. Bearing sealing plate; 23. Gear ring; 24. Internal fan; 25. Internal fan blades; 26. Internal gear; 27. Gear mounting rod; 28. Telescopic cylinder; 29. ​​Piston rod; 30. Fixing block; 31. Return spring; 32. Pneumatic plate; 33. Air-cooled channel; 34. Permanent magnet. Detailed Implementation

[0036] This invention relates to an explosion-proof, high-efficiency air-cooled electric drum, particularly suitable for flammable and explosive environments such as mining. It achieves efficient thermal management through a multi-stage heat dissipation mechanism, ensuring stable operation within a sealed explosion-proof enclosure. The specific embodiments of the invention are described in detail below with reference to the accompanying drawings. It should be noted that these embodiments are intended to fully disclose the invention but should not be construed as limiting the scope of protection. Those skilled in the art can make modifications or adjustments within the spirit of this invention.

[0037] As described in the background section, there are shortcomings in the existing technology. In order to solve the above-mentioned technical problems, this application proposes an explosion-proof high-efficiency air-cooled electric drum and a mining explosion-proof equipment equipped with the drum.

[0038] Example 1:

[0039] like Figure 1-11As shown, the explosion-proof high-efficiency air-cooled electric drum includes an electric drum 2. Its overall structure includes an explosion-proof housing 3, a stator core 11, a stator coil 12, a central shaft 13, a bearing 15, a bearing sleeve 20, and a bearing housing 1. The explosion-proof housing 3 is made of high-strength explosion-proof material and is cylindrical. Bearing sleeves 20 are integrally connected to both ends. The bearing sleeves 20 are annular structures used to support the bearing 15. The stator core 11 is fixedly installed at the center of the explosion-proof housing 3 and is made of multiple layers of silicon steel sheets to reduce eddy current losses. The stator coil 12 is wound on the stator core 11. The stator coil 12 is made of insulated copper wire and is treated with varnish to enhance insulation and thermal conductivity. The central shaft 13 passes through the center of the stator core 11 and is fixed by a key connection or interference fit. The central shaft 13 is a hollow structure with an internal air-cooling channel 33. The air-cooling channel 33 extends axially along the central shaft 13 for airflow. Bearings 15 are fitted onto the outer surfaces of both sides of the stator core 11. Bearings 15 are deep groove ball bearings or roller bearings; their outer ring mates with the inner wall of the bearing sleeve 20, and their inner ring is fixed to the stator core 11 or the central shaft 13. Bearing housing 1 is fitted onto the outer surface of the bearing sleeve 20 and connected to the external equipment frame by bolts or welding, thereby supporting the entire electric drum 2. The bearing housing 1 has a grease inlet to extend the service life of the bearings 15. The inner wall of the explosion-proof housing 3 is uniformly distributed with several permanent magnets 34. The permanent magnets 34 are made of high-energy-product materials such as neodymium iron boron and are embedded into the inner wall of the explosion-proof housing 3 by bonding or mechanical fixing. The permanent magnets 34 are arranged radially and interact with the magnetic field formed by the stator core 11, driving the explosion-proof housing 3 to rotate.

[0040] An air-cooled assembly 4 is installed on one side of the electric roller 2. The air-cooled assembly 4 includes an air-cooled side frame 21, a motor 17, an outer fan blade 16, a filter screen 18, and an end plate 19. The air-cooled side frame 21 is a rectangular or circular frame, fixed to the bearing sleeve 20 via a flange connection. A sealing ring is provided at the flange connection to ensure airtightness. The motor 17 is fixed inside the air-cooled side frame 21. The motor 17 is an explosion-proof three-phase asynchronous motor or a DC motor, and its output shaft is connected to the outer fan blade 16 via a coupling. The outer fan blade 16 is a centrifugal or axial flow fan blade, and its number and angle of blades are optimized to provide efficient airflow. The filter screen 18 is installed at the air inlet of the air-cooled side frame 21. The filter screen 18 is made of metal or synthetic fiber material and is used to filter dust and particulate matter in the air to prevent clogging of the air duct. The end plate 19 is fixed to the end of the air-cooled side frame 21 by hinges or bolts, facilitating the removal and cleaning of the filter screen 18. The air-cooled side frame 21 is connected to the air-cooled channel 33 of the central shaft 13, and the other end of the air-cooled channel 33 is connected to the air outlet 5. The air outlet 5 is located at the connection between the electric roller 2 and the driver 6, and the air outlet 5 has a mesh or louver structure to exhaust hot air. When the air-cooled assembly 4 is working, the motor 17 drives the outer fan blades 16 to rotate, drawing in external air into the air-cooled side frame 21. After being filtered by the filter screen 18, the air enters the air-cooled channel 33, flows through the interior of the central shaft 13, carries away the heat generated by the stator core 11 and stator coils 12, and is finally discharged from the air outlet 5. This direct air-cooling method reduces the temperature of the stator area, but due to the limited space of the air-cooled channel 33, an auxiliary heat dissipation mechanism is required.

[0041] On the other side of the electric drum 2, a driver 6 is installed. The driver 6 is a frequency converter or servo driver, and its housing is also designed to be explosion-proof. The driver 6 is connected to the stator coil 12 via a cable, converting the external DC power supply into three-phase AC power to supply the stator coil 12. The driver 6 has internal overcurrent, overvoltage, and overheat protection circuits to ensure safe operation. An air outlet 5 is provided at the connection between the driver 6 and the electric drum 2 to coordinate airflow.

[0042] The outer surface of the explosion-proof housing 3 is provided with an external heat exchange assembly 9, which includes several external heat dissipation longitudinal fins 7 and several external heat dissipation transverse fins 8. The external heat dissipation longitudinal fins 7 are elongated metal sheets, preferably made of aluminum or copper, and are uniformly fixed to the outer surface of the explosion-proof housing 3 by welding or bonding. The external heat dissipation longitudinal fins 7 extend along the axial direction of the explosion-proof housing 3 and are evenly distributed around its circumference. The external heat dissipation transverse fins 8 are annular or sheet-like structures, perpendicularly connected to the external heat dissipation longitudinal fins 7, forming a grid-like heat dissipation surface. The external heat dissipation transverse fins 8 are fixed to the external heat dissipation longitudinal fins 7 by riveting or welding, increasing the heat dissipation area. When the electric roller 2 operates, the explosion-proof housing 3 rotates, driving the external heat exchange assembly 9 to move in the air, generating forced convection and accelerating heat dissipation. The surfaces of the external heat dissipation longitudinal fins 7 and external heat dissipation transverse fins 8 can be coated with a high-emissivity coating to enhance the thermal radiation effect.

[0043] To improve the heat dissipation efficiency of the external heat exchanger assembly 9, several side air pipes 10 are connected to the surface of the air-cooled side frame 21. The side air pipes 10 are flexible or rigid pipes, one end of which connects to the interior of the air-cooled side frame 21, and the other end extends between adjacent external heat dissipation fins 7. The outlet direction of the side air pipes 10 faces the gap between the external heat dissipation fins 8. When air is ejected from the air-cooled side frame 21 through the side air pipes 10, it interacts with the rotating external heat dissipation fins 8, generating vortices. This vortex disturbance disrupts the boundary layer, increases the airflow rate, and thus significantly enhances convective heat transfer. The arrangement and angle of the side air pipes 10 are optimized using computational fluid dynamics to ensure that the airflow covers the entire heat dissipation surface.

[0044] An internal fan 24 is provided inside the explosion-proof enclosure 3 to promote internal air circulation. The internal fan 24 includes a gear ring 23, internal fan blades 25, an internal gear 26, and a gear mounting rod 27. The gear ring 23 is fixed to the inner wall of one end of the explosion-proof enclosure 3. The gear ring 23 is a ring gear with involute or circular arc teeth. The gear mounting rod 27 is fixed to the end face of the stator core 11. The gear mounting rod 27 is a shaft-like structure, and the internal gear 26 and the internal fan blades 25 are rotatably mounted on its outer surface through bearings or sleeves. The internal gear 26 meshes with the gear ring 23. When the explosion-proof enclosure 3 rotates, the gear ring 23 drives the internal gear 26 to rotate, thereby driving the internal fan blades 25 to rotate. The internal fan blades 25 are axial flow fan blades, and their rotation agitates the air inside the explosion-proof enclosure 3, forming a forced internal circulation airflow. This internal circulation makes the hot air evenly distributed, avoids local overheating, and enhances heat conduction through contact with the inner wall of the explosion-proof enclosure 3.

[0045] The inner wall of the central shaft 13 is integrally provided with several internal heat dissipation fins 14. The internal heat dissipation fins 14 are axially protruding structures and are distributed circumferentially along the inner wall of the air-cooling channel 33. The internal heat dissipation fins 14 increase the inner surface area of ​​the central shaft 13 and improve the heat exchange efficiency with the cooling air. The cross-sectional shape of the internal heat dissipation fins 14 is trapezoidal or corrugated to reduce airflow resistance.

[0046] A bearing sealing plate 22 is fixedly installed on the end face of the bearing 15 inside the bearing sleeve 20. The bearing sealing plate 22 is an annular plate, which is fixed to the end face of the bearing 15 by bolts or clips to prevent dust and moisture from entering the interior of the bearing 15 and extend the bearing life. The bearing sealing plate 22 is made of stainless steel or engineering plastic, and its sealing lip contacts the inner wall of the bearing sleeve 20 to form a dynamic seal.

[0047] The invention also includes an internal air-cooling assembly for actively exchanging hot air inside the explosion-proof housing 3. The internal air-cooling assembly includes several telescopic cylinders 28, a piston rod 29, a fixing block 30, a return spring 31, and a pneumatic plate 32. The telescopic cylinder 28 is a cylindrical structure, with one end inserted into the end face of the explosion-proof housing 3 and fixed by welding or threading. The other end of the telescopic cylinder 28 communicates with the interior of the explosion-proof housing 3, forming an airflow channel. The piston rod 29 is a rod-shaped component, with one end extending and retracting within the telescopic cylinder 28, and the other end fixedly connected to the pneumatic plate 32. The pneumatic plate 32 is a plate-shaped structure located between adjacent external heat dissipation longitudinal fins 7. The fixing block 30 is fixed to the outer surface of the explosion-proof housing 3 by welding, located on both sides of the piston rod 29. The return spring 31 connects between the fixing block 30 and the pneumatic plate 32, providing a restoring force. When the electric roller 2 operates, the airflow ejected from the side air pipe 10 impacts the pneumatic plate 32, pushing the piston rod 29 out of the telescopic cylinder 28 and compressing the return spring 31. The movement of piston rod 29 draws hot air from inside the explosion-proof housing 3 into the telescopic cylinder 28. Subsequently, under the action of return spring 31, piston rod 29 returns to its original position, pumping cooled air from the telescopic cylinder 28 back into the explosion-proof housing 3. This reciprocating motion accelerates the internal airflow and dissipates heat through the walls of the telescopic cylinder 28, lowering the air temperature. The telescopic cylinder 28 may be made of a high thermal conductivity material to enhance heat exchange.

[0048] In the specific assembly, the stator core 11 and stator coil 12 are first assembled into a stator assembly, and then pressed onto the central shaft 13. Subsequently, bearings 15 are installed at both ends of the stator core 11, and bearing sealing plates 22 are fitted onto them. The explosion-proof housing 3 is pre-installed with permanent magnets 34, and then fitted onto the stator assembly from one end, aligning the bearing 15 with the bearing sleeve 20. The bearing sleeve 20 is fixed to the explosion-proof housing 3 with bolts. The bearing seat 1 is fitted over the bearing sleeve 20 and fixed to the frame. The air-cooled side frame 21 of the air-cooled assembly 4 is connected to the flange of the bearing sleeve 20, and the motor 17 and outer fan blades 16 are installed in place. The outer heat exchanger assembly 9 has its outer longitudinal heat dissipation fins 7 and outer transverse heat dissipation fins 8 welded together before the explosion-proof housing 3 rotates. One end of the side air pipe 10 is connected to the air-cooled side frame 21, and the other end is fixed to the gap between the outer longitudinal heat dissipation fins 7. The gear mounting rod 27 of the internal fan 24 is fixed to the stator core 11. After assembly, the internal gear 26 and the internal fan blade 25 mesh with the gear ring 23. The telescopic cylinder 28 of the internal air-cooling assembly is inserted into the end face of the explosion-proof housing 3. After the piston rod 29 and the pneumatic plate 32 are installed, they are positioned by the fixing block 30 and the return spring 31. The driver 6 is connected to one side of the electric roller 2 and the power is turned on.

[0049] Example 2:

[0050] This embodiment provides a mine explosion-proof belt conveyor equipped with this explosion-proof high-efficiency air-cooled electric drum. This conveyor is mainly used in underground coal mine working face transport roadways.

[0051] The conveyor frame is welded from mining steel and its surface is treated with rust prevention. The electric drum 2 is mounted on both ends of the frame via bearing seats 1. The bottom of the bearing seats 1 is equipped with shock-absorbing rubber pads. The drive system adopts the explosion-proof electric drum 2 of this invention.

[0052] In actual operation, when the conveyor starts, the driver 6 first performs soft start control, and the current slowly rises to the rated value. At the same time, the motor 17 of the air-cooled assembly 4 starts synchronously, and the outer fan blades 16 rotate to generate cooling airflow.

[0053] The cooling airflow is split into two paths: the main part directly cools the central shaft 13 and stator assembly through the air-cooling channel 33; the other part is delivered to the external heat exchange assembly 9 area through the side air pipe 10. The outlet direction of the side air pipe 10 can form a rotating vortex between the heat sinks, enhancing the heat exchange effect.

[0054] The working principle is as follows: The driver 6 receives an external DC power supply, converts it into three-phase AC power, and supplies it to the stator coil 12. When the stator coil 12 is energized, it generates a rotating magnetic field, which interacts with the permanent magnet 34, driving the explosion-proof housing 3 to rotate. The explosion-proof housing 3 acts as the rotor, driving the external heat exchange assembly 9 and the gear ring 23 to move. Simultaneously, the motor 17 of the air-cooling assembly 4 operates, driving the external fan blades 16 to draw in air. After being filtered by the filter 18, part of the air flows through the air-cooling channel 33 through the central shaft 13, cooling the stator area before being discharged from the air outlet 5; the other part is sprayed onto the external heat exchange assembly 9 through the side air pipe 10, generating eddies to enhance heat dissipation. The internal fan 24 rotates with the gear ring 23, agitating the internal air. The internal air-cooling assembly utilizes the airflow from the side air pipe 10 to drive the pneumatic plate 32, causing the piston rod 29 to reciprocate, drawing in and pumping out internal air to achieve heat exchange. This multi-stage cooling system ensures the efficient operation of the electric drum 2 in high-temperature, explosion-proof environments.

[0055] The ingenuity of this invention lies in its integration of direct air cooling, external forced convection, internal circulation, and active pumping mechanisms, achieving synergistic heat dissipation through structural optimization. The rotation of the external heat exchange component 9 and the vortex generation of the side air duct 10 improve external heat dissipation efficiency; the internal fan 24 avoids internal hot spots; and the internal air cooling component reduces internal temperature aerodynamically. All components operate within an explosion-proof enclosure, meeting safety standards. This invention is particularly suitable for harsh environments such as mines and chemical plants, exhibiting high reliability and long service life.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An explosion-proof, high-efficiency air-cooled electric drum, characterized in that: The electric drum body includes an explosion-proof shell (3), a stator core (11) and a stator coil (12) fixedly installed inside the explosion-proof shell (3), and a central shaft (13) passing through the center of the stator core (11). The two ends of the explosion-proof shell (3) are supported on the bearing seat (1) by bearing sleeves (20) and bearings (15). It also includes an air-cooling assembly (4) disposed on one side of the electric drum body. The air-cooling assembly (4) includes an air-cooling side frame (21), a motor (17) installed in the air-cooling side frame (21), and an outer fan blade (16) driven by the motor (17). The air-cooling side frame (21) is connected to the bearing sleeve (20), and the interior of the air-cooling side frame (21) is connected to one end of the air-cooling channel (33) opened in the central shaft (13). The other end of the air-cooling channel (33) is connected to the air outlet (5) disposed on the other side of the electric drum body. The external heat exchange assembly (9) is disposed on the outer surface of the explosion-proof housing (3). The external heat exchange assembly (9) includes a plurality of external heat dissipation longitudinal plates (7) and external heat dissipation transverse plates (8) connected to the external heat dissipation longitudinal plates (7). An internal fan (24) is installed inside the explosion-proof housing (3). The internal fan (24) includes a gear ring (23) fixed to the inner wall of the explosion-proof housing (3), a gear mounting rod (27) fixed to the end face of the stator core (11), an internal gear (26) rotatably mounted on the gear mounting rod (27) and meshing with the gear ring (23), and an internal fan blade (25) coaxially connected to the internal gear (26). In addition, an internal air-cooling assembly is provided at the end of the explosion-proof housing (3). The internal air-cooling assembly includes several telescopic cylinders (28) communicating with the inside of the explosion-proof housing (3), a piston rod (29) that can reciprocate within the telescopic cylinders (28), a pneumatic plate (32) fixed to the outer end of the piston rod (29), a fixing block (30) fixed to the outer surface of the explosion-proof housing (3) and located on the side of the piston rod (29), and a return spring (31) connected between the fixing block (30) and the pneumatic plate (32). The pneumatic plate (32) is located between adjacent external heat dissipation longitudinal plates (7). Several side air pipes (10) are also connected to the air-cooling side frame (21) of the air-cooling assembly (4). One end of the side air pipe (10) is connected to the inside of the air-cooling side frame (21), and the other end has its outlet located between adjacent external heat dissipation longitudinal plates (7).

2. The explosion-proof high-efficiency air-cooled electric drum according to claim 1, characterized in that: The air-cooling channel (33) of the central shaft (13) is integrally provided with several internal heat dissipation longitudinal fins (14).

3. The explosion-proof high-efficiency air-cooled electric drum according to claim 2, characterized in that: A bearing sealing plate (22) is fixedly installed on the end face of the bearing (15) inside the bearing sleeve (20).

4. The explosion-proof high-efficiency air-cooled electric drum according to claim 3, characterized in that: The internal air-cooling component has multiple telescopic cylinders (28) that are evenly inserted around the end face of the explosion-proof housing (3).

5. The explosion-proof high-efficiency air-cooled electric drum according to claim 4, characterized in that: The air-cooled component (4) is provided with a removable filter (18) at the air inlet.

6. The explosion-proof high-efficiency air-cooled electric drum according to claim 5, characterized in that: A permanent magnet (34) is fixedly installed on the inner wall of the explosion-proof housing (3).

7. The explosion-proof high-efficiency air-cooled electric drum according to claim 6, characterized in that: The external heat dissipation longitudinal fins (7) and external heat dissipation transverse fins (8) together form a grid-like heat dissipation surface.

8. The explosion-proof high-efficiency air-cooled electric drum according to claim 7, characterized in that: The outlet direction of the side air pipe (10) is toward the gap between the external heat dissipation fins (8).

9. A mining explosion-proof equipment, characterized in that, It is equipped with an explosion-proof high-efficiency air-cooled electric drum as described in any one of claims 1 to 8.

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