Gearbox cooling system for a wind turbine generator

Abstract

The application discloses a kind of gear box cooling systems for wind generating set, it is related to wind power generation technical field, wherein, gear box cooling system for wind generating set includes first fan blade assembly, heat dissipation mechanism and heat conduction mechanism, main shaft can drive first fan blade assembly rotation, cabin is provided with multiple heat dissipation ports;Heat dissipation mechanism includes heat dissipation assembly, cooling circulation pipeline and oil pump, cooling circulation pipeline includes the oil inlet section, heat dissipation section and oil return section communicated in sequence, the oil inlet section is communicated with gear box, heat dissipation assembly is connected with heat dissipation section, and heat dissipation assembly is set to the air outlet side of first fan blade assembly, first fan blade assembly can complete the air of heat exchange with heat dissipation assembly and be blown to heat conduction ring by heat dissipation port, to reduce the temperature of heat dissipation assembly, promote the cooling effect of lubricating oil in heat dissipation section, effectively reduce the heat of gear box, and heat conduction ring can absorb heat and transmit heat to blade, to improve the temperature of blade and melt ice on its surface.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, and in particular to a gearbox cooling system for wind turbine generator sets. Background Technology

[0002] Currently, as the impact of the greenhouse effect becomes increasingly severe, people are paying more and more attention to clean energy, thus increasing the demand for wind power generation equipment. Existing wind turbines work by rotating their blades in the wind, causing the connected main shaft to rotate and converting wind energy into mechanical energy. The main shaft then drives the rotor inside the generator to rotate. The rotor cuts magnetic field lines in the stator's magnetic field, generating an induced electromotive force, which converts mechanical energy into electrical energy. This electrical energy can then be transmitted to the power grid or used in other electrical devices.

[0003] Existing wind turbine generators often experience situations where the gearbox overheats, forcing the reduction of blade speed to maintain normal gearbox operation, which severely impacts wind power generation efficiency; or, the blade surface is covered with ice, causing the blade speed to decrease, which also severely impacts wind power generation efficiency. Summary of the Invention

[0004] The main objective of this invention is to propose a gearbox cooling system for wind turbine generator sets, aiming to solve the technical problem of how to ensure the power generation efficiency of wind turbine generator sets.

[0005] To achieve the above objectives, the present invention proposes a gearbox cooling system for wind turbine generator sets, comprising a nacelle, a main shaft, a hub, blades, a gearbox, and a generator. Both the gearbox and the generator are housed within the nacelle. The blades are disposed on the hub. One end of the main shaft is connected to the hub, and the other end of the main shaft is connected to the input shaft of the gearbox. The output shaft of the gearbox is connected to the input shaft of the generator. The gearbox cooling system for wind turbine generator sets further includes:

[0006] The first fan blade assembly is located inside the nacelle and is connected to the main shaft so that the main shaft can drive the first fan blade assembly to rotate. When the first fan blade assembly rotates synchronously with the main shaft, the air outlet side faces the hub. The end of the nacelle facing the hub is provided with multiple heat dissipation vents.

[0007] The heat dissipation mechanism includes a heat dissipation component, a cooling circulation pipeline, and an oil pump disposed on the cooling circulation pipeline. The cooling circulation pipeline includes an oil inlet section, a heat dissipation section, and an oil return section connected in sequence. The end of the oil inlet section away from the heat dissipation section is connected to the bottom of the gearbox. The heat dissipation component is connected to the heat dissipation section and is disposed on the air outlet side when the first fan blade assembly rotates synchronously with the main shaft, for reducing the temperature of the heat dissipation section. The end of the oil return section away from the heat dissipation section is connected to the gearbox. The oil pump is used to drive the lubricating oil flowing into the oil inlet section to flow sequentially through the heat dissipation section and the oil return section before flowing into the gearbox.

[0008] The heat dissipation vent faces the air outlet side when the first fan blade assembly rotates synchronously with the main shaft.

[0009] A heat-conducting mechanism is located outside the nacelle. The heat-conducting mechanism includes a heat-conducting ring and a heat-conducting component connected to each other. The heat-conducting ring is connected to the side of the blade near the hub. The heat dissipation port faces the heat-conducting ring. The heat-conducting component is attached to the blade and extends along the length of the blade. Both the heat-conducting ring and the heat-conducting component are made of heat-conducting materials.

[0010] In one embodiment, the gearbox cooling system for a wind turbine generator set further includes a switching mechanism and a second blade assembly. The second blade assembly is located inside the nacelle. The first and second blade assemblies are axially opposite to each other on both sides of the heat dissipation assembly. Both the first and second blade assemblies are detachably connected to the main shaft. When the second blade assembly rotates synchronously with the main shaft, its exhaust side faces away from the hub. Both the first and second blade assemblies are drive-connected to the switching mechanism. The switching mechanism can drive the second blade assembly to separate from the main shaft and simultaneously drive the first blade assembly to connect to the main shaft so that the first blade assembly rotates synchronously with the main shaft. Alternatively, the switching mechanism can drive the first blade assembly to separate from the main shaft and simultaneously drive the second blade assembly to connect to the main shaft so that the second blade assembly rotates synchronously with the main shaft. A ventilation hole is provided at the end of the nacelle away from the hub.

[0011] In one embodiment, the first fan blade assembly includes a first bearing, a first sleeve, and a plurality of first fan blades. The first sleeve is detachably connected to the main shaft. The plurality of first fan blades are spaced apart circumferentially on the outer wall of the first sleeve. The first sleeve is fitted onto the outer wall of the first bearing. The inner hole of the first bearing allows the main shaft to pass through, and the inner hole of the first bearing is coaxially aligned with the main shaft and has a clearance fit. The second fan blade assembly includes a second bearing, a second sleeve, and a plurality of second fan blades. The second sleeve is detachably connected to the main shaft. The plurality of second fan blades are spaced apart circumferentially on the outer wall of the second sleeve. The second sleeve is fitted onto the outer wall of the second bearing. The inner hole of the second bearing allows the main shaft to pass through, and the inner hole of the second bearing is coaxially aligned with the main shaft. The shaft is set with clearance fit; the switching mechanism includes a drive assembly, a transmission assembly, and a guide assembly. The guide assembly extends axially along the main shaft and is connected to the engine compartment. The inner rings of the first bearing and the second bearing are movably mounted on the guide assembly so that the inner rings of the first bearing and the second bearing can move relative to the guide assembly along the axial direction of the main shaft. The drive assembly is connected to the inner rings of the first bearing and the second bearing through the transmission assembly. The drive assembly can drive the first sleeve to connect to the main shaft and simultaneously drive the second sleeve to separate from the main shaft through the transmission assembly, or the drive assembly can drive the first sleeve to separate from the main shaft and simultaneously drive the second sleeve to connect to the main shaft through the transmission assembly.

[0012] In one embodiment, the first sleeve includes a first cylindrical body and a first insertion section connected to each other, and a plurality of first fan blades are evenly spaced along the circumference of the first cylindrical body. The first cylindrical body is sleeved on the outer wall of the first bearing. The second sleeve includes a second cylindrical body and a second insertion section connected to each other, and a plurality of second fan blades are evenly spaced along the circumference of the second cylindrical body. The second cylindrical body is sleeved on the outer wall of the second bearing. The main shaft includes a shaft body and a first positioning block and a second positioning block disposed on the side wall of the shaft body. One end of the shaft body is connected to the hub, and the other end of the shaft body is connected to the input shaft of the gearbox. The inner hole of the first bearing allows the shaft body to pass through. The inner hole of the first bearing is coaxially arranged with the shaft body and has a clearance fit. The second bearing... The inner hole of the first bearing allows the shaft to pass through, and the inner hole of the second bearing is coaxially arranged with the shaft and clearance fit; the first positioning block is located on the side of the first fan blade assembly away from the second fan blade assembly, and the first positioning block has a first slot for the first insertion segment to be inserted; the second positioning block is located on the side of the second fan blade assembly away from the first fan blade assembly, and the second positioning block has a second slot for the second insertion segment to be inserted; the drive assembly can drive the first insertion segment into the first slot through the transmission assembly, and simultaneously drive the second insertion segment out of the second slot; or, the drive assembly can drive the first insertion segment out of the first slot through the transmission assembly, and simultaneously drive the second insertion segment into the second slot.

[0013] In one embodiment, the transmission assembly includes a fixed base, a first elastic element, a second elastic element, a first pull rope, and a second pull rope. The drive assembly includes a drive motor. One end of the first pull rope is connected to the inner ring of the first bearing, and the other end of the first pull rope is wound around the rotating shaft of the drive motor along a first direction. One end of the second pull rope is connected to the inner ring of the second bearing, and the other end of the second pull rope is wound around the rotating shaft of the drive motor along a second direction. The first direction and the second direction are opposite. The fixed base is disposed between the first fan blade assembly and the second fan blade assembly. One end of the first elastic element is connected to the inner ring of the first bearing, and the other end of the first elastic element is connected to the fixed base. One end of the second elastic element is connected to the inner ring of the second bearing, and the other end of the second elastic element is connected to the fixed base.

[0014] In one embodiment, the guide assembly includes a main guide rod, the inner ring of the first bearing has a first groove, the inner ring of the second bearing has a second groove, both the first groove and the second groove are slidably engaged with the main guide rod, and the openings of both the first groove and the second groove are oriented towards the ground.

[0015] In one embodiment, the guiding assembly further includes auxiliary guide rods. The inner ring of the first bearing is provided with a first guide groove, and the inner ring of the second bearing is provided with a second guide groove. Both the first guide groove and the second guide groove are slidably engaged with the auxiliary guide rods. There are multiple auxiliary guide rods. The number of first guide grooves is the same as the number of auxiliary guide rods and they are arranged in a one-to-one correspondence. The number of second guide grooves is the same as the number of auxiliary guide rods and they are arranged in a one-to-one correspondence. The multiple first guide grooves are arranged at intervals along the circumference of the first bearing, and the multiple second guide grooves are arranged at intervals along the circumference of the second bearing.

[0016] In one embodiment, the heat-conducting ring includes a ring body and a connector. One end of the connector is connected to the blade, and the other end of the connector is connected to the ring body. The distance between the ring body and the end of the nacelle facing the hub along the axial direction of the main shaft is d, where 15mm≤d≤50mm.

[0017] In one embodiment, the gearbox cooling system for the wind turbine generator set further includes a fan located inside the nacelle, the fan being positioned opposite the heat dissipation assembly, and the fan's exhaust side facing the heat dissipation assembly.

[0018] In one embodiment, the heat dissipation assembly includes a heat dissipation plate and a plurality of heat dissipation fins. One side of the heat dissipation plate is connected to the heat dissipation section, and the other side of the heat dissipation plate is connected to the plurality of heat dissipation fins. The plurality of heat dissipation fins extend along the axial direction of the main shaft and are arranged at intervals in a direction perpendicular to the axial direction of the main shaft.

[0019] The technical solution of this invention employs an oil pump to extract high-temperature lubricating oil from the gearbox through an oil inlet section. This high-temperature lubricating oil flows through the oil inlet section to a heat dissipation section. Since the heat dissipation section is connected to the heat dissipation assembly, heat exchange occurs between the two sections, transferring heat to the heat dissipation assembly. The heat dissipation assembly then exchanges heat with the air in the engine compartment, causing the air temperature near the heat dissipation assembly to rise. Furthermore, the first fan blade assembly is connected to the main shaft, allowing the main shaft to rotate while also driving the first fan blade assembly. Because the air outlet of the first fan blade assembly faces the heat dissipation vent and the heat dissipation assembly, the airflow generated by the first fan blade assembly sequentially blows over the heat dissipation assembly and the heat dissipation vent. The airflow interacts with the heat dissipation assembly at the heat dissipation section. The components exchange heat, the airflow heats up, and the heat dissipation components cool down, effectively improving the cooling effect of the heat dissipation section on the lubricating oil. The cooled lubricating oil can provide better lubrication for the components in the gearbox, reduce the resistance between the components, reduce the loss of kinetic energy due to this resistance, and transfer more kinetic energy to the generator, thereby effectively improving the generator's power generation efficiency. The heated airflow flows out of the nacelle through the heat dissipation vents and blows onto the heat conduction ring, where it exchanges heat with the ring, transferring heat to the ring. The heat conduction ring then transfers the heat to the blades through the heat conduction components, thereby increasing the blade temperature and assisting in de-icing and snow removal, thus ensuring the power generation efficiency of the wind turbine generator. Attached Figure Description

[0020] 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 the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of an embodiment of the gearbox cooling system for a wind turbine generator set provided by the present invention, without the installation of a heat conduction mechanism.

[0022] Figure 2 This is a partial structural schematic diagram of an embodiment of a gearbox cooling system for a wind turbine generator set provided by the present invention, which is equipped with a heat-conducting mechanism.

[0023] Figure 3 A schematic diagram of the structure of an embodiment of the switching mechanism, the first fan blade assembly, and the second fan blade assembly provided by the present invention;

[0024] Figure 4 for Figure 3 A structural diagram from another perspective;

[0025] Figure 5An exploded structural diagram of an embodiment of the switching mechanism, the first fan blade assembly, and the second fan blade assembly provided by the present invention;

[0026] Figure 6 This is a schematic diagram of the structure of an embodiment of the first bearing and the second bearing provided by the present invention;

[0027] Figure 7 This is a schematic diagram of the connection between the heat dissipation mechanism and the gearbox provided by the present invention.

[0028] Explanation of icon numbers:

[0029] 100. Gearbox cooling system for wind turbine generator sets; 1. Nacelle; 11. Heat dissipation vent; 2. Main shaft; 21. Shaft body; 211. First positioning block; 2111. First slot; 212. Second positioning block; 2121. Second slot; 3. Hub; 4. Blade; 5. Gearbox; 6. First blade assembly; 61. First bearing; 611. First slide groove; 612. First guide groove; 62. First sleeve; 621. First sleeve body; 622. First insertion section; 63. First blade; 7. Heat dissipation mechanism; 71. Heat dissipation assembly; 711. Heat dissipation plate; 712. Heat dissipation fins; 72. Cooling circulation pipeline; 721. Oil inlet section; 722. Heat dissipation section; 723. 73. Oil pump; 8. Heat conduction mechanism; 81. Heat conduction ring; 811. Ring body; 812. Connector; 82. Heat conduction component; 9. Switching mechanism; 91. Drive assembly; 911. Drive motor; 92. Transmission assembly; 921. Fixing base; 922. First elastic element; 923. Second elastic element; 924. First pull rope; 925. Second pull rope; 93. Guide assembly; 931. Main guide rod; 932. Auxiliary guide rod; 10. Second fan blade assembly; 101. Second bearing; 1011. Second slide groove; 1012. Second guide groove; 102. Second sleeve; 1021. Second cylinder body; 1022. Second insertion section; 103. Second fan blade.

[0030] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0033] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0034] Currently, as the impact of the greenhouse effect becomes increasingly severe, people are paying more and more attention to clean energy, thus increasing the demand for wind power generation equipment. Existing wind turbines work by rotating their blades in the wind, causing the connected main shaft to rotate and converting wind energy into mechanical energy. The main shaft then drives the rotor inside the generator to rotate. The rotor cuts magnetic field lines in the stator's magnetic field, generating an induced electromotive force, which converts mechanical energy into electrical energy. This electrical energy can then be transmitted to the power grid or used in other electrical devices.

[0035] Existing wind turbine generators often experience situations where the gearbox overheats, forcing the reduction of blade speed to maintain normal gearbox operation, which severely impacts wind power generation efficiency; or, the blade surface is covered with ice, causing the blade speed to decrease, which also severely impacts wind power generation efficiency.

[0036] The inventors discovered that the faster the spindle speed, the higher the temperature inside the gearbox. Increased gearbox temperature leads to a decrease in lubricating oil viscosity, resulting in a thinner protective lubricating film between friction surfaces. This reduces load-bearing capacity and fails to effectively isolate direct metal-to-metal contact between gears and bearings, increasing the risk of wear. Tooth surface wear is exacerbated, leading to scratches, pits, and broken teeth, causing abnormal noises in the gearbox and severely impacting its lifespan. Conversely, reducing the spindle speed reduces wind power generation efficiency. Furthermore, the inventors found that some regions experience frequent rain and snowfall in winter. Wind turbines are typically located in remote, sparsely populated areas. Relying on manual snow and ice removal would incur enormous labor costs. Using external thermal energy equipment, which converts electrical energy into heat, would reduce the power output of the wind power system if some of the electricity generated by the wind turbine were used to power the thermal energy equipment.

[0037] This invention proposes a gearbox cooling system for wind turbine generator sets, aiming to solve the technical problem of how to ensure the power generation efficiency of wind turbine generator sets.

[0038] Please see Figures 1 to 3 as well as Figure 7In one embodiment of the present invention, the gearbox cooling system 100 for a wind turbine generator set includes a nacelle 1, a main shaft 2, a hub 3, blades 4, a gearbox 5, and a generator. The gearbox 5 and the generator are both housed within the nacelle 1. The blades 4 are disposed on the hub 3. One end of the main shaft 2 is connected to the hub 3, and the other end of the main shaft 2 is connected to the input shaft of the gearbox 5. The output shaft of the gearbox 5 is connected to the input shaft of the generator. The gearbox cooling system 100 for a wind turbine generator set also includes a first blade assembly 6, a heat dissipation mechanism 7, and a heat conduction mechanism 8. The first blade assembly 6 is located within the nacelle 1 and is connected to the main shaft 2 so that the main shaft 2 can drive the first blade assembly 6 to rotate. When the first blade assembly 6 rotates synchronously with the main shaft 2, its exhaust side faces the hub 3. The end of the nacelle 1 facing the hub 3 is provided with multiple heat dissipation vents 11. The heat dissipation mechanism 7 includes a heat dissipation component 71, a cooling circulation pipe 72, and an oil pump 73 disposed on the cooling circulation pipe 72. The cooling circulation pipe 72 includes... The oil inlet section 721, the heat dissipation section 722, and the oil return section 723 are connected in a secondary manner. The end of the oil inlet section 721 away from the heat dissipation section 722 is connected to the bottom of the gearbox 5. The heat dissipation assembly 71 is connected to the heat dissipation section 722 and is located on the air outlet side when the first fan blade assembly 6 rotates synchronously with the main shaft 2, in order to reduce the temperature of the heat dissipation section 722. The end of the oil return section 723 away from the heat dissipation section 722 is connected to the gearbox 5. The oil pump 73 is used to drive the lubricating oil flowing into the oil inlet section 721 to flow sequentially through the gearbox 5. After the heat dissipation section 722 and the oil return section 723, the oil flows into the gearbox 5; the heat dissipation port 11 faces the air outlet side when the first fan blade assembly 6 rotates synchronously with the main shaft 2; the heat conduction mechanism 8 is located outside the nacelle 1, and the heat conduction mechanism 8 includes a heat conduction ring 81 and a heat conduction element 82 connected to each other. The heat conduction ring 81 is connected to the side of the blade 4 near the hub 3. The heat dissipation port 11 faces the heat conduction ring 81. The heat conduction element 82 is attached to the blade 4 and extends along the length direction of the blade 4. Both the heat conduction ring 81 and the heat conduction element 82 are made of heat conduction material.

[0039] The technical solution of this invention uses an oil pump 73 to extract high-temperature lubricating oil from the gearbox 5 through an oil inlet section 721. The high-temperature lubricating oil flows through the oil inlet section 721 to the heat dissipation section 722. Since the heat dissipation section 722 is connected to the heat dissipation component 71, the lubricating oil in the heat dissipation section 722 exchanges heat with the heat dissipation component 71, thereby transferring heat to the heat dissipation component 71. The heat dissipation component 71 then exchanges heat with the air in the engine compartment 1, thereby increasing the air temperature near the heat dissipation component 71. Furthermore, the first fan blade assembly 6 is connected to the main shaft 2, so that the main shaft 2 can also drive the first fan blade assembly 6 to rotate when it rotates. Since the air outlet side of the first fan blade assembly 6 faces the heat dissipation port 11 and the heat dissipation component 71, the airflow generated by the first fan blade assembly 6 blows sequentially over the heat dissipation component 71 and the heat dissipation port 11. The airflow exchanges heat with the heat dissipation component 71 at the heat dissipation component 71, increasing the airflow temperature and decreasing the temperature of the heat dissipation component 71, effectively improving the cooling effect of the lubricating oil in the heat dissipation section 722. The cooling lubricating oil not only provides better lubrication for the components inside the gearbox 5, reducing the resistance to relative movement between components and minimizing energy loss due to this resistance, but also allows more kinetic energy to be transferred to the generator, thereby effectively improving the generator's power generation efficiency. Furthermore, it can exchange heat with the components inside the gearbox 5, thus reducing the gearbox 5's temperature and extending its lifespan. The rising airflow flows to the heat dissipation vent 11 and exits the nacelle 1, blowing onto the heat-conducting ring 81, where it exchanges heat with the ring. The airflow transfers heat to the ring, which then transfers it through the heat-conducting element 82 to the blades 4, thereby increasing the blades 4's temperature. This helps melt ice or snow on the blades 4's surface, reducing the load on the blades and increasing the blades 4's rotational speed under the same wind volume, thus improving the wind turbine's power generation efficiency and ensuring its effectiveness. It should be noted that the main shaft 2 of the gearbox cooling system 100 for the wind turbine generator set in this embodiment can only rotate in one direction and cannot rotate in both directions. That is, if the main shaft 2 rotates clockwise, it cannot rotate counterclockwise. Therefore, the rotation direction of the main shaft 2 is determined, and the air outlet side of the first fan blade assembly 6 is also determined, thereby ensuring that the airflow blown out from the air outlet side can flow smoothly to the heat dissipation port 11. It should also be noted that the oil pump 73 is an existing oil pump 73, the cooling circulation pipe 72 can use an existing oil supply pipe, and the oil pump 73 can be installed on the cooling circulation pipe 72 using existing installation methods, so that the oil pump 73 can drive the lubricating oil in the gearbox 5 to flow sequentially through the oil inlet section 721, the heat dissipation section 722, and the oil return section 723 before returning to the gearbox 5; the heat-conducting ring 81 and the heat-conducting component 82 can be made of metal materials with high thermal conductivity, such as copper or aluminum, etc., without specific limitations.

[0040] Please see Figures 3 to 5In one embodiment, the gearbox cooling system 100 for a wind turbine generator set further includes a switching mechanism 9 and a second blade assembly 10. The second blade assembly 10 is located inside the nacelle 1. The first blade assembly 6 and the second blade assembly 10 are arranged opposite each other on both sides of the heat dissipation assembly 71 along the axial direction of the main shaft 2. Both the first blade assembly 6 and the second blade assembly 10 are detachably connected to the main shaft 2. When the second blade assembly 10 rotates synchronously with the main shaft 2, the air outlet side faces away from the hub 3. Both the first blade assembly 6 and the second blade assembly 10 are drive-connected to the switching mechanism 9. The switching mechanism 9 can drive the second blade assembly 10 to separate from the main shaft 2 and simultaneously drive the first blade assembly 6 to connect with the main shaft 2 so that the first blade assembly 6 rotates synchronously with the main shaft 2. Alternatively, the switching mechanism 9 can drive the first blade assembly 6 to separate from the main shaft 2 and simultaneously drive the second blade assembly 10 to connect with the main shaft 2 so that the second blade assembly 10 rotates synchronously with the main shaft 2. A ventilation hole is provided at the end of the nacelle 1 away from the hub 3.

[0041] The inventors' research also revealed that if the first blade assembly 6 is always connected to the main shaft 2, although the heat generated by the gearbox 5 can be used to melt ice and remove snow from the blades 4 in the cold winter, as the seasons change and the hot summer arrives, if the heat generated by the gearbox 5 is still transferred to the blades 4, it may cause the blades 4 to deform due to heat, thereby reducing the rotational speed of the blades 4 and affecting the power generation efficiency.

[0042] This embodiment adds a switching structure and a second blade assembly 10. In summer, the switching structure can separate the first blade assembly 6 from the main shaft 2, preventing the main shaft 2 from driving the first blade assembly 6 to rotate. At the same time, in order to maintain efficient cooling of the gearbox 5, when the switching structure separates the first blade assembly 6 from the main shaft 2, the second blade assembly 10 will connect to the main shaft 2, allowing the main shaft 2 to drive the second blade assembly 10 to rotate. Since the air outlet direction of the second blade assembly 10 when rotating synchronously with the main shaft 2 is opposite to that of the first blade assembly 6 and the main shaft 2 when rotating synchronously, the airflow enters from the heat dissipation port 11 instead of being blown out from it. This avoids blowing high-temperature airflow onto the heat conduction mechanism 8, thus preventing the blade 4 from deforming due to the hot airflow blown out from the heat dissipation port 11, and ensuring the power generation efficiency of the wind turbine generator.

[0043] Furthermore, since the air outlet side of the second fan blade assembly 10 also faces the heat dissipation assembly 71, the airflow entering the nacelle 1 from the heat dissipation port 11 will be blown towards the heat dissipation assembly 71 by the second fan blade assembly 10, thereby accelerating the airflow around the heat dissipation assembly 71 and reducing the temperature of the heat dissipation assembly 71 more quickly. This effectively reduces the temperature of the lubricating oil in the heat dissipation section 722, so that the cooled lubricating oil can not only provide better lubrication for the components in the gearbox 5, but also reduce the resistance between the components and reduce the loss of kinetic energy due to this resistance, so that more kinetic energy can be transferred to the generator, thereby effectively improving the generator's power generation efficiency and ensuring the generator's power generation efficiency. The airflow that has completed heat exchange with the heat dissipation assembly 71 will be discharged to the outside of the nacelle 1 through the ventilation hole. Since the ventilation hole is located at the end of the nacelle 1 away from the hub 3, the heat generated by this airflow will not have much impact on the blades 4, so that the blades 4 are not easily deformed by heat and thus affect the power generation efficiency.

[0044] Please see Figures 3 to 5In one embodiment, the first fan blade assembly 6 includes a first bearing 61, a first sleeve 62, and a plurality of first fan blades 63. The first sleeve 62 is detachably connected to the main shaft 2. The plurality of first fan blades 63 are spaced apart along the circumference of the first sleeve 62 on the outer wall of the first sleeve 62. The first sleeve 62 is fitted onto the outer wall of the first bearing 61. The inner hole of the first bearing 61 allows the main shaft 2 to pass through. The inner hole of the first bearing 61 is coaxially arranged with the main shaft 2 and has a clearance fit. The second fan blade assembly 10 includes a second bearing 101, a second sleeve 102, and a plurality of second fan blades 103. The second sleeve 102 is detachably connected to the main shaft 2. The plurality of second fan blades 103 are spaced apart along the circumference of the second sleeve 102 on the outer wall of the second sleeve 102. The second sleeve 102 is fitted onto the outer wall of the second bearing 101. The inner hole of the second bearing 101 allows the main shaft 2 to pass through. The hole is coaxially arranged with the main shaft 2 and has a clearance fit; the switching mechanism 9 includes a drive assembly 91, a transmission assembly 92 and a guide assembly 93. The guide assembly 93 extends along the axial direction of the main shaft 2 and is connected to the engine compartment 1. The inner rings of the first bearing 61 and the second bearing 101 are movably mounted on the guide assembly 93 so that the inner rings of the first bearing 61 and the second bearing 101 can move relative to the guide assembly 93 along the axial direction of the main shaft 2. The drive assembly 91 is connected to the inner rings of the first bearing 61 and the second bearing 101 through the transmission assembly 92. The drive assembly 91 can drive the first sleeve 62 to connect with the main shaft 2 and simultaneously drive the second sleeve 102 to separate from the main shaft 2 through the transmission assembly 92, or the drive assembly 91 can drive the first sleeve 62 to separate from the main shaft 2 and simultaneously drive the second sleeve 102 to connect with the main shaft 2 through the transmission assembly 92.In this configuration, the drive assembly 91 drives the first bearing 61 and the second bearing 101 to move relative to the guide assembly 93 via the transmission assembly 92. This, in turn, drives the first sleeve 62 to move via the first bearing 61, and the second sleeve 102 to move via the second bearing 101. When the first sleeve 62 is connected to the main shaft 2, since the first sleeve 62 is fitted onto the outer wall of the first bearing 61, and the inner hole of the first bearing 61 is coaxially aligned with the main shaft 2 with a clearance fit, the rotation of the main shaft 2 does not cause the inner ring of the first bearing 61 to rotate, ensuring the reliability of the connection between the inner ring of the first bearing 61 and the guide assembly 93. Simultaneously, it also ensures that the first sleeve 62 is coaxially aligned with the main shaft 2, thus guaranteeing the stability of the synchronous rotation of the first sleeve 62 and the main shaft 2, allowing the first sleeve 62 to rotate steadily. The first fan blade 63 mounted on the main shaft 2 moves, thereby generating airflow towards the hub 3. When the first sleeve 62 separates from the main shaft 2 and the second sleeve 102 connects to the main shaft 2, since the second sleeve 102 is fitted on the outer wall of the second bearing 101 and the inner hole of the second bearing 101 is coaxially arranged with the main shaft 2 and has a clearance fit, the rotation of the main shaft 2 will not drive the inner ring of the second bearing 101 to rotate, ensuring the reliability of the connection between the inner ring of the second bearing 101 and the guide assembly 93. At the same time, it also ensures that the second sleeve 102 is coaxially arranged with the main shaft 2, thereby ensuring the stability of the synchronous rotation of the second sleeve 102 and the main shaft 2, so that the second sleeve 102 can stably drive the second fan blade 103 mounted on it to move, thereby generating airflow towards the heat dissipation assembly 71. It should be noted that both the first bearing 61 and the second bearing 101 are existing bearings, as are the first fan blade 63 and the second fan blade 103. Bearings consist of an inner ring and an outer ring; the outer wall of the bearing referred to here is the outer wall of the outer ring. It should also be noted that if the first sleeve 62 rotates clockwise when connected to the main shaft 2, then after the first sleeve 62 is separated from the main shaft 2 and the second sleeve 102 is connected to the main shaft 2, the second sleeve 102 also rotates clockwise. Because the shapes of the first fan blade 63 and the second fan blade 103 are different, although both the first sleeve 62 and the second sleeve 102 rotate clockwise, their airflow directions are not the same. Furthermore, when the first sleeve 62 is separated from the main shaft 2 and the second sleeve 102 is connected to the main shaft 2, the airflow generated by the second fan blade 103 may cause the first fan blade 63 to move, thereby causing the first sleeve 62 to rotate counterclockwise, so that the airflow generated by the first fan blade 63 is in the same direction as the airflow actively generated by the second fan blade 103.

[0045] Please see Figures 4 to 6In one embodiment, the first sleeve 62 includes a first sleeve body 621 and a first insertion section 622 connected to each other. A plurality of first fan blades 63 are evenly spaced along the circumference of the first sleeve body 621. The first sleeve body 621 is fitted onto the outer wall of the first bearing 61. The second sleeve 102 includes a second sleeve body 1021 and a second insertion section 1022 connected to each other. A plurality of second fan blades 103 are evenly spaced along the circumference of the second sleeve body 1021. The second sleeve body 1021 is fitted onto the outer wall of the second bearing 101. The main shaft 2 includes a shaft body 21 and a first positioning block 211 and a second positioning block 212 disposed on the side wall of the shaft body 21. One end of the shaft body 21 is connected to the hub 3, and the other end of the shaft body 21 is connected to the input shaft of the gearbox 5. The inner hole of the first bearing 61 allows the shaft body 21 to pass through. The inner hole of the first bearing 61 is coaxially arranged with the shaft body 21 and has a clearance fit. The second bearing 61... The inner hole of bearing 1 allows shaft 21 to pass through, and the inner hole of bearing 101 is coaxially arranged with shaft 21 and clearance fit; the first positioning block 211 is located on the side of the first fan blade assembly 6 away from the second fan blade assembly 10, and the first positioning block 211 has a first slot 2111 for the first insertion segment 622 to be inserted; the second positioning block 212 is located on the side of the second fan blade assembly 10 away from the first fan blade assembly 6, and the second positioning block 212 has a second slot 2121 for the second insertion segment 1022 to be inserted; the drive assembly 91 can drive the first insertion segment 622 into the first slot 2111 through the transmission assembly 92, and at the same time drive the second insertion segment 1022 out of the second slot 2121; or, the drive assembly 91 can drive the first insertion segment 622 out of the first slot 2111 through the transmission assembly 92, and at the same time drive the second insertion segment 1022 into the second slot 2121. The drive assembly 91 is used to move the first cylindrical body 621 and the second cylindrical body 1021 through the transmission assembly 92. When the first insertion segment 622 on the first cylindrical body 621 is inserted into the first slot 2111, the second insertion segment 1022 on the second cylindrical body 1021 is disengaged from the second slot 2121, so that the spindle 2 only drives the first cylindrical body 621 to rotate, thereby generating airflow towards the heat dissipation port 11. When the drive assembly 91 drives the first insertion segment 622 on the first cylindrical body 621 to disengage from the first slot 2111, the second insertion segment 1022 on the second cylindrical body 1021 is inserted into the second slot 2121, so that the spindle 2 only drives the second cylindrical body 1021 to rotate, thereby generating airflow towards the ventilation hole. The first insertion segment 622 and the first slot 2111 are inserted and engaged, and the second insertion segment 1022 and the second slot 2121 are inserted and engaged, thereby facilitating the detachable connection between the first sleeve 62 and the spindle 2, and facilitating the detachable connection between the second sleeve 102 and the spindle 2.

[0046] According to an embodiment of the present invention, slots are provided on the first sleeve 62 and the second sleeve 102, and a first pin is provided on the spindle 2 for inserting into the slot of the first sleeve 62. The spindle 2 is also provided with a second pin for inserting into the slot on the second sleeve 102. Through the insertion and engagement of the slot and the pin, the first sleeve 62 and the spindle 2 can be easily detachedly connected, and the second sleeve 102 and the spindle 2 can be easily detachedly connected.

[0047] Please see Figures 3 to 5In one embodiment, the transmission assembly 92 includes a fixed base 921, a first elastic element 922, a second elastic element 923, a first pull rope 924, and a second pull rope 925. The drive assembly 91 includes a drive motor 911. One end of the first pull rope 924 is connected to the inner ring of the first bearing 61, and the other end of the first pull rope 924 is wound around the rotating shaft of the drive motor 911 in a first direction. One end of the second pull rope 925 is connected to the inner ring of the second bearing 101, and the other end of the second pull rope 925 is wound around the rotating shaft of the drive motor 911 in a second direction. The first direction and the second direction are opposite to each other. The fixed base 921 is disposed between the first fan blade assembly 6 and the second fan blade assembly 10. One end of the first elastic element 922 is connected to the inner ring of the first bearing 61, and the other end of the first elastic element 922 is connected to the fixed base 921. One end of the second elastic element 923 is connected to the inner ring of the second bearing 101, and the other end of the second elastic element 923 is connected to the fixed base 921. When the drive motor 911 rotates in the first direction, the length of the first pull rope 924 wound around the rotating shaft of the drive motor 911 decreases, and the length of the second pull rope 925 wound around the rotating shaft of the drive motor 911 increases. Because the length of the first pull rope 924 wound around the rotating shaft decreases, the first elastic element 922, which is in a compressed state, can drive the first bearing 61 to move to the left relative to the guide assembly 93. Simultaneously, because the length of the second pull rope 925 wound around the rotating shaft of the drive motor 911 increases, the second bearing 101 connected to the second pull rope 925 is dragged to the left, continuously compressing the second elastic element 923 until the first insertion section 622, which has moved to the left, is inserted into the first slot 2111. The second insertion segment 1022 moves until it disengages from the second slot 2121; when the drive motor 911 rotates in the second direction, the length of the first pull rope 924 wound around the rotating shaft of the drive motor 911 gradually increases, and the length of the second pull rope 925 wound around the rotating shaft of the drive motor 911 gradually decreases. The first pull rope 924 drags the first bearing 61 to the right, thereby causing the second insertion segment 1022 to move to the right. The second elastic element 923, which is in a compressed state, will cause the second bearing 101 to move to the right relative to the guide assembly 93, thereby causing the second insertion segment 1022 to move to the right until the second insertion segment 1022 is inserted into the second slot 2121 and the first insertion segment 622 disengages from the first slot 2111.It should be noted that even if the second insertion segment 1022 disengages from the second slot 2121, the first insertion segment 622, due to its misalignment with the first slot 2111, will have its end away from the first cylindrical body 621 abutting against the end of the first positioning block 211 facing the first cylindrical body 621. Since the first elastic element 922 is in a compressed state, as long as the first slot 2111 rotates to a position directly opposite the first insertion segment 622, the elastic force generated by the first elastic element 922 can drive the first insertion segment 622 to insert into the first slot 2121. Within 111, this effectively ensures that the first insertion segment 622 can be smoothly inserted into the first slot 2111. Similarly, even if the second insertion segment 1022 fails to be smoothly inserted into the second slot 2121 on the first attempt, because the second elastic element 923 is in a compressed state, when the second slot 2121 moves to the position corresponding to the second insertion segment 1022, the elastic force generated by the second elastic element 923 will drive the second insertion segment 1022 into the second slot 2121, ensuring that the second insertion segment 1022 can be smoothly inserted into the second slot 2121. It should also be noted that the drive motor 911 can be an existing stepper motor or servo motor, and no specific restrictions are imposed here; the first pull rope 924 and the second pull rope 925 are both existing pull ropes, and the first elastic element 922 and the second elastic element 923 can be springs or rubber blocks or other structural components with elastic deformation capabilities, and no specific restrictions are imposed here either. The first direction can be either clockwise or counterclockwise, and there is no restriction here. When the first direction is clockwise, the second direction is counterclockwise, and the axis of the main shaft 2 is . Figure 3 The left and right directions are shown.

[0048] Please see Figures 4 to 6 In one embodiment, the guide assembly 93 includes a main guide rod 931. The inner ring of the first bearing 61 has a first groove 611, and the inner ring of the second bearing 101 has a second groove 1011. Both the first groove 611 and the second groove 1011 are slidably engaged with the main guide rod 931, and the openings of both the first groove 611 and the second groove 1011 are facing the ground. By setting the main guide rod 931 to pass through the first groove 611 and the second groove 1011 respectively, it not only guides the movement of the first bearing 61 and the second bearing 101, but also provides reliable support for the first bearing 61 and the second bearing 101. The two ends of the main guide rod 931 can be connected to the inner wall of the cabin 1 or other immovable structural components within the cabin 1, without specific limitations.

[0049] Please see Figures 4 to 6In one embodiment, the guide assembly 93 further includes an auxiliary guide rod 932. The inner ring of the first bearing 61 is provided with a first guide groove 612, and the inner ring of the second bearing 101 is provided with a second guide groove 1012. The first guide groove 612 and the second guide groove 1012 are both slidably engaged with the auxiliary guide rod 932. There are multiple auxiliary guide rods 932. The number of first guide grooves 612 and auxiliary guide rods 932 are the same and they are arranged in a one-to-one correspondence. The number of second guide grooves 1012 and auxiliary guide rods 932 are the same and they are arranged in a one-to-one correspondence. The multiple first guide grooves 612 are arranged sequentially at intervals along the circumference of the first bearing 61, and the multiple second guide grooves 1012 are arranged sequentially at intervals along the circumference of the second bearing 101. By setting multiple auxiliary guide rods 932, each of which passes through the corresponding first guide groove 612 and second guide groove 1012, the guiding effect on the first bearing 61 and the second bearing 101 is further enhanced. It also achieves effective positioning of the inner rings of the first bearing 61 and the second bearing 101, and restricts the rotation of the inner rings of the first bearing 61 and the second bearing 101 relative to the main shaft 2.

[0050] Please see Figure 2 In one embodiment, the heat-conducting ring 81 includes a ring body 811 and a connector 812. One end of the connector 812 is connected to the blade 4, and the other end of the connector 812 is connected to the ring body 811. The distance between the ring body 811 and the end of the nacelle 1 facing the hub 3 along the axial direction of the main shaft 2 is d, where 15mm≤d≤50mm. By controlling the distance between the ring body 811 and the end of the nacelle 1 with the heat dissipation vent 11, the airflow blowing from the outlet can contact the ring body 811 as much as possible and quickly for heat exchange, reducing interference from other airflows on the airflow blowing from the heat dissipation vent 11. The reason why the ring body 811 is not completely covered by the end of the nacelle 1 with the heat dissipation vent 11 is mainly because when the first fan blade assembly 6 needs to stop rotating and the second fan blade assembly 10 needs to rotate, the heat dissipation vent 11 can be used as an air inlet. If the heat dissipation vent 11 is blocked, air cannot enter from the heat dissipation vent 11, and thus an airflow channel cannot be formed to accelerate the heat dissipation of the heat dissipation component 71. Therefore, the ring body 811 cannot be pressed against the nacelle 1. The connector 812 is also made of thermally conductive material. The connector 812 can be a connecting rod or a connecting block, etc., and no specific restrictions are made here.

[0051] In one embodiment, the gearbox cooling system 100 for a wind turbine generator set further includes a fan (not shown), located inside the nacelle 1, positioned opposite the heat dissipation assembly 71, with the fan's outlet facing the heat dissipation assembly 71. By adding a fan to dissipate heat from the heat dissipation assembly 71, the airflow around the heat dissipation assembly 71 is accelerated, effectively improving the heat dissipation efficiency of the heat dissipation assembly 71. Furthermore, if the fan's outlet faces the hub 3, it can also assist the first fan blade assembly 6 in blowing the hot air that has exchanged heat with the heat dissipation assembly 71 from the heat dissipation port 11 towards the ring body 811, improving the efficiency of heat transfer and enhancing the effect of de-icing and snow removal on the blades 4. If the fan's outlet faces away from the hub 3, the fan can assist the second fan blade assembly 10 in dissipating heat from the heat dissipation assembly 71, enhancing the heat dissipation efficiency of the lubricating oil in the heat dissipation section 722. The cooled lubricating oil can not only provide better lubrication for the components in the gearbox 5, but also reduce the resistance between the components, reducing the loss of kinetic energy due to this resistance, allowing more kinetic energy to be transferred to the generator, thereby effectively improving the generator's power generation efficiency. The fan can be an existing fan, and the fan can be powered by an external power source or by a battery; there are no specific restrictions.

[0052] Please see Figure 4 In one embodiment, the heat dissipation assembly 71 includes a heat dissipation plate 711 and a plurality of heat dissipation fins 712. One side of the heat dissipation plate 711 is connected to a heat dissipation section 722, and the other side of the heat dissipation plate 711 is connected to a plurality of heat dissipation fins 712. The plurality of heat dissipation fins 712 extend along the axial direction of the main shaft 2 and are arranged sequentially at intervals along a direction perpendicular to the axial direction of the main shaft 2. By setting multiple heat dissipation fins 712, the contact area between the heat dissipation component 71 and the air is increased, thereby improving the heat dissipation efficiency of the heat dissipation component 71. This improves the cooling effect on the lubricating oil in the heat dissipation section 722. The cooled lubricating oil can not only provide better lubrication for the components in the gearbox 5, but also reduce the resistance between the components and reduce the loss of kinetic energy due to this resistance, so that more kinetic energy can be transferred to the generator, thereby effectively improving the generator's power generation efficiency. Furthermore, each first heat dissipation fin 712 extends along the axial direction of the main shaft 2, and multiple heat dissipation fins 712 are arranged sequentially at intervals along a direction perpendicular to the axial direction of the main shaft 2. This allows a heat dissipation airflow channel extending along the axial direction of the main shaft 2 to be formed between two adjacent heat dissipation fins 712, facilitating airflow and effectively enhancing the heat dissipation capacity of the heat dissipation component 71.

[0053] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformations made based on the technical concept of the present invention and the contents of the specification and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A gearbox cooling system for a wind turbine generator set, comprising a nacelle (1), a main shaft (2), a hub (3), blades (4), a gearbox (5), and a generator, wherein the gearbox (5) and the generator are both disposed within the nacelle (1), the blades (4) are disposed on the hub (3), one end of the main shaft (2) is connected to the hub (3), the other end of the main shaft (2) is connected to the input shaft of the gearbox (5), and the output shaft of the gearbox (5) is connected to the input shaft of the generator, characterized in that, The gearbox cooling system (100) for wind turbine generator sets also includes: The first fan blade assembly (6) is located inside the nacelle (1). The first fan blade assembly (6) is connected to the main shaft (2) so that the main shaft (2) can drive the first fan blade assembly (6) to rotate. When the first fan blade assembly (6) rotates synchronously with the main shaft (2), the air outlet side faces the hub (3). The nacelle (1) is provided with multiple heat dissipation vents at the end facing the hub (3). A heat dissipation mechanism (7) includes a heat dissipation component (71), a cooling circulation pipe (72), and an oil pump (73) disposed on the cooling circulation pipe (72). The cooling circulation pipe (72) includes an oil inlet section (721), a heat dissipation section (722), and an oil return section (723) connected in sequence. The end of the oil inlet section (721) away from the heat dissipation section (722) is connected to the bottom of the gearbox (5). The heat dissipation component (71) and the heat dissipation section (723) are connected in sequence. 2) The heat dissipation component (71) is located on the air outlet side when the first fan blade assembly (6) and the main shaft (2) rotate synchronously, and is used to reduce the temperature of the heat dissipation section (722); the end of the oil return section (723) away from the heat dissipation section (722) is connected to the gearbox (5), and the oil pump (73) is used to drive the lubricating oil flowing into the oil inlet section (721) to flow through the heat dissipation section (722) and the oil return section (723) in sequence before flowing into the gearbox (5); The heat dissipation port faces the air outlet side when the first fan blade assembly (6) and the main shaft (2) rotate synchronously; A heat conduction mechanism (8) is located outside the cabin (1). The heat conduction mechanism (8) includes a heat conduction ring (81) and a heat conduction component (82) connected to each other. The heat conduction ring (81) is connected to the side of the blade (4) near the hub (3). The heat dissipation port faces the heat conduction ring (81). The heat conduction component (82) is attached to the blade (4) and extends along the length direction of the blade (4). Both the heat conduction ring (81) and the heat conduction component (82) are made of heat-conducting material. The gearbox cooling system (100) for the wind turbine generator set further includes a switching mechanism (9) and a second fan blade assembly (10). The second fan blade assembly (10) is located inside the nacelle (1). The first fan blade assembly (6) and the second fan blade assembly (10) are arranged opposite each other on both sides of the heat dissipation assembly (71) along the axial direction of the main shaft (2). Both the first fan blade assembly (6) and the second fan blade assembly (10) are detachably connected to the main shaft (2). When the second fan blade assembly (10) rotates synchronously with the main shaft (2), the air outlet side faces away from the hub (3). The first fan blade assembly (6) and the second fan blade assembly (10) All components (10) are connected to the switching mechanism (9) for transmission. The switching mechanism (9) can drive the second fan blade assembly (10) to separate from the main shaft (2) and simultaneously drive the first fan blade assembly (6) to connect with the main shaft (2) so that the first fan blade assembly (6) and the main shaft (2) rotate synchronously. Alternatively, the switching mechanism (9) can drive the first fan blade assembly (6) to separate from the main shaft (2) and simultaneously drive the second fan blade assembly (10) to connect with the main shaft (2) so that the second fan blade assembly (10) and the main shaft (2) rotate synchronously. A ventilation hole is provided at the end of the cabin (1) away from the hub (3).

2. The gearbox cooling system for wind turbine generator sets as described in claim 1, characterized in that, The first fan blade assembly (6) includes a first bearing (61), a first sleeve (62), and a plurality of first fan blades (63). The first sleeve (62) is detachably connected to the main shaft (2). The plurality of first fan blades (63) are spaced apart on the outer wall of the first sleeve (62) along the circumference of the first sleeve (62). The first sleeve (62) is fitted onto the outer wall of the first bearing (61). The inner hole of the first bearing (61) is through which the main shaft (2) passes. The inner hole of the first bearing (61) is coaxially arranged with the main shaft (2) and has a clearance fit. The two-blade assembly (10) includes a second bearing (101), a second sleeve (102), and a plurality of second blades (103). The second sleeve (102) is detachably connected to the main shaft (2). The plurality of second blades (103) are spaced apart on the outer wall of the second sleeve (102) along the circumference of the second sleeve (102). The second sleeve (102) is fitted onto the outer wall of the second bearing (101). The inner hole of the second bearing (101) is for the main shaft (2) to pass through, and the inner hole of the second bearing (101) is coaxially arranged with the main shaft (2). Furthermore, the clearance fit is maintained; the switching mechanism (9) includes a drive assembly (91), a transmission assembly (92), and a guide assembly (93). The guide assembly (93) extends axially along the main shaft (2) and is connected to the engine compartment (1). The inner rings of the first bearing (61) and the second bearing (101) are movably mounted on the guide assembly (93) so that the inner rings of the first bearing (61) and the second bearing (101) can move relative to the guide assembly (93) axially along the main shaft (2). The component (91) is connected to the inner ring of the first bearing (61) and the inner ring of the second bearing (101) through the transmission assembly (92). The drive assembly (91) can drive the first sleeve (62) to connect with the main shaft (2) through the transmission assembly (92) and simultaneously drive the second sleeve (102) to separate from the main shaft (2). Alternatively, the drive assembly (91) can drive the first sleeve (62) to separate from the main shaft (2) through the transmission assembly (92) and simultaneously drive the second sleeve (102) to connect with the main shaft (2).

3. The gearbox cooling system for wind turbine generator sets as described in claim 2, characterized in that, The first sleeve (62) includes a first cylindrical body (621) and a first insertion section (622) connected to each other. A plurality of first fan blades (63) are evenly spaced along the circumference of the first cylindrical body (621), and the first cylindrical body (621) is sleeved on the outer wall of the first bearing (61). The second sleeve (102) includes a second cylindrical body (1021) and a second insertion section (1022) connected to each other. A plurality of second fan blades (103) are evenly spaced along the circumference of the second cylindrical body (1021), and the second cylindrical body (621)... The main shaft (2) includes a shaft body (21) and a first positioning block (211) and a second positioning block (212) disposed on the side wall of the shaft body (21). One end of the shaft body (21) is connected to the hub (3), and the other end of the shaft body (21) is connected to the input shaft of the gearbox (5). The inner hole of the first bearing (61) is for the shaft body (21) to pass through. The inner hole of the first bearing (61) is coaxially arranged with the shaft body (21) and clearance fit. The inner hole of the second bearing (101) is for the shaft body (21) to pass through. The shaft (21) passes through, and the inner hole of the second bearing (101) is coaxially arranged with the shaft (21) and clearance-fitted; the first positioning block (211) is located on the side of the first fan blade assembly (6) away from the second fan blade assembly (10), and the first positioning block (211) has a first slot (2111) for the first insertion segment (622) to be inserted; the second positioning block (212) is located on the side of the second fan blade assembly (10) away from the first fan blade assembly (6), and the second positioning block (212) has a slot (2111) for the second insertion segment (101) to be inserted. 022) The second slot (2121) is inserted, and the drive component (91) can drive the first insertion segment (622) to be inserted into the first slot (2111) through the transmission component (92), and at the same time drive the second insertion segment (1022) to be disengaged from the second slot (2121); or, the drive component (91) can drive the first insertion segment (622) to be disengaged from the first slot (2111) through the transmission component (92), and at the same time drive the second insertion segment (1022) to be inserted into the second slot (2121).

4. The gearbox cooling system for wind turbine generator sets as described in claim 2, characterized in that, The transmission assembly (92) includes a fixed base (921), a first elastic element (922), a second elastic element (923), a first pull rope (924), and a second pull rope (925). The drive assembly (91) includes a drive motor (911). One end of the first pull rope (924) is connected to the inner ring of the first bearing (61), and the other end of the first pull rope (924) is wound around the rotating shaft of the drive motor (911) along a first direction. One end of the second pull rope (925) is connected to the inner ring of the second bearing (101), and the other end of the second pull rope (925) is wound around the rotating shaft of the drive motor (911) along a second direction. The first direction and the second direction are arranged opposite to each other around the rotating shaft of the drive motor (911); the fixed seat (921) is disposed between the first fan blade assembly (6) and the second fan blade assembly (10); one end of the first elastic member (922) is connected to the inner ring of the first bearing (61), and the other end of the first elastic member (922) is connected to the fixed seat (921); one end of the second elastic member (923) is connected to the inner ring of the second bearing (101), and the other end of the second elastic member (923) is connected to the fixed seat (921).

5. The gearbox cooling system for wind turbine generator sets as described in claim 2, characterized in that, The guide assembly (93) includes a main guide rod (931), the inner ring of the first bearing (61) is provided with a first groove (611), the inner ring of the second bearing (101) is provided with a second groove (1011), the first groove (611) and the second groove (1011) are both slidably engaged with the main guide rod (931), and the openings of the first groove (611) and the second groove (1011) are both set facing the ground.

6. The gearbox cooling system for wind turbine generator sets as described in claim 5, characterized in that, The guide assembly (93) further includes an auxiliary guide rod (932). The inner ring of the first bearing (61) is provided with a first guide groove (612), and the inner ring of the second bearing (101) is provided with a second guide groove (1012). The first guide groove (612) and the second guide groove (1012) are slidably engaged with the auxiliary guide rod (932). There are multiple auxiliary guide rods (932). The number of first guide grooves (612) is the same as the number of auxiliary guide rods (932) and they are arranged in a one-to-one correspondence. The number of second guide grooves (1012) is the same as the number of auxiliary guide rods (932) and they are arranged in a one-to-one correspondence. Multiple first guide grooves (612) are arranged sequentially at intervals along the circumference of the first bearing (61), and multiple second guide grooves (1012) are arranged sequentially at intervals along the circumference of the second bearing (101).

7. The gearbox cooling system for a wind turbine generator set as described in any one of claims 1 to 6, characterized in that, The heat-conducting ring (81) includes a ring body (811) and a connector (812). One end of the connector (812) is connected to the blade (4), and the other end of the connector (812) is connected to the ring body (811). The distance between the ring body (811) and the end of the nacelle (1) facing the hub (3) along the axial direction of the main shaft (2) is d, where 15mm≤d≤50mm.

8. The gearbox cooling system for a wind turbine generator set as described in any one of claims 1 to 6, characterized in that, The gearbox cooling system (100) for the wind turbine generator set also includes a fan located inside the nacelle (1), the fan being positioned opposite the heat dissipation assembly (71), and the exhaust side of the fan facing the heat dissipation assembly (71).

9. The gearbox cooling system for a wind turbine generator set as described in any one of claims 1 to 6, characterized in that, The heat dissipation assembly (71) includes a heat dissipation plate (711) and a plurality of heat dissipation fins (712). One side of the heat dissipation plate (711) is connected to the heat dissipation section (722), and the other side of the heat dissipation plate (711) is connected to the plurality of heat dissipation fins (712). The plurality of heat dissipation fins (712) extend along the axial direction of the main shaft (2), and the plurality of heat dissipation fins (712) are arranged sequentially at intervals along a direction perpendicular to the axial direction of the main shaft (2).

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