A gearbox and a drone

Abstract

The application provides a gearbox and a UAV, and belongs to the technical field of gearboxes. The gearbox comprises a gearbox body and a transmission assembly. The transmission assembly comprises a first gear and a second gear which are engaged with each other. The gearbox body has a first gear cavity and a second gear cavity which are in communication with each other. The first gear is located in the first gear cavity, and the second gear is located in the second gear cavity. The gearbox body has a concave wall which is arranged to face the second gear. At least part of the concave wall is recessed to the inner side of the second gear cavity, so that the outer wall of the gearbox body forms a recessed structure. The recessed structure greatly reduces the redundant space inside the gearbox body, reduces the overall weight, improves the load ratio of the UAV, and meets the dual requirements of portability and safety of equipment in the aviation field.

Description

Technical Field

[0001] This application belongs to the field of gearbox technology, and particularly relates to a gearbox and an unmanned aerial vehicle. Background Technology

[0002] With the development of the unmanned aerial vehicle (UAV) aviation field, the proportion of unmanned helicopters is gradually increasing, especially heavy-load helicopters. In the power system of heavy-load UAV helicopters, the gearbox plays a crucial role. Its main purpose is to convert the engine's high speed into high torque, which can successfully maintain the power for takeoff. Therefore, the reliability of the gearbox is crucial, and the aviation field needs a gearbox structure that is both lightweight and safe.

[0003] Traditional gearbox designs have excessively large cavity spaces, occupying a lot of structural space and being quite heavy, which cannot meet the needs of heavy-duty unmanned helicopters. Therefore, there is an urgent need for a gearbox structure that is suitable for aviation applications and combines portability and safety. Utility Model Content

[0004] This application provides a gearbox and a drone. By setting a recessed structure on the outer wall of the gearbox, the redundant cavity space of the second gear chamber is effectively reduced, thereby reducing the overall structural space occupied by the gearbox and achieving a compact design of the gearbox. At the same time, the reasonable compression of the cavity space reduces the amount of material used in the gearbox, significantly reducing the weight of the gearbox itself. This solves the problem that traditional gearbox designs have excessively large cavity spaces, occupying a lot of structural space and being heavy, which cannot meet the needs of heavy-load unmanned helicopters.

[0005] In a first aspect, embodiments of this application provide a gearbox, including a housing; The housing has a first gear cavity and a second gear cavity that are interconnected. A first gear is disposed in the first gear cavity and a second gear is disposed in the second gear cavity. The first gear and the second gear that mesh with each other form the transmission assembly of the gearbox. The housing has a concave wall facing the second gear, at least a portion of which is recessed into the inner side of the second gear cavity, so that the outer wall of the housing forms a recessed structure.

[0006] In one feasible implementation, the concave wall is positioned near the bottom of the housing.

[0007] In one feasible implementation, the concave wall includes a first plate and a second plate; The first plate is positioned facing the first gear, and the second plate is positioned facing the second gear, with the first plate and the second plate at a preset angle; wherein, the distance between the side of the first plate connected to the second plate and the second gear is less than the distance between the side of the first plate away from the second plate and the second gear.

[0008] In one feasible implementation, the first plate is perpendicular to or forms a first angle with the axis of the first gear.

[0009] In one feasible implementation, the second plate is perpendicular to or forms a second angle with the axis of the second gear.

[0010] In one feasible implementation, the concave wall further includes a reinforcing plate, one side of which is connected to the first plate and the other side of which is connected to the second plate, and the reinforcing plate, the first plate, and the second plate form a triangular support structure.

[0011] In one feasible implementation, the upper part of the housing is provided with an oil injection hole, which is connected to the first gear cavity or the second gear cavity; The bottom of the housing is provided with an oil drain port, which is connected to the second gear cavity.

[0012] In one feasible implementation, the housing includes a lower cover; The lower cover is detachably connected to the bottom of the box, and the oil drain port is located on the lower cover.

[0013] In one feasible implementation, the housing further includes a top cover; The top cover is detachably fitted onto the top of the housing. The top cover has a first shaft hole, which engages with the first drive shaft of the transmission assembly.

[0014] Secondly, embodiments of this application provide an unmanned aerial vehicle (UAV) including the aforementioned gearbox.

[0015] This application provides a gearbox and a drone. By providing a concave wall on the housing facing the second gear, with at least a portion of the concave wall recessed into the second gear cavity, a recessed structure is formed on the outer wall of the housing. This effectively reduces the redundant cavity space of the second gear cavity, thereby reducing the overall structural space occupied by the housing and achieving a compact design of the gearbox. Simultaneously, the reasonable compression of the cavity space reduces the amount of material used in the housing, significantly reducing the weight of the gearbox itself and meeting the aviation industry's requirements for lightweight gearboxes. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of a gearbox provided in one embodiment of this application; Figure 2 This is an exploded view of a gearbox provided in one embodiment of this application; Figure 3 This is a front sectional view of a gearbox provided in an embodiment of this application; Figure 4 This is a schematic diagram of the box body from a first perspective according to an embodiment of this application; Figure 5 This is a schematic diagram of the box body from a second perspective according to an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a transmission assembly provided in one embodiment of this application; Figure 7 This is a table of core design parameters for a transmission component gear provided in one embodiment of this application; Figure 8 yes Figure 7 A table showing the force calculation formulas for spur and helical bevel gears with the parameters shown; Figure 9 According to Figure 8 The table shows the force calculation results for spur and bevel gears after calculation using the formulas shown.

[0017] Explanation of reference numerals in the attached figures: 100 - Housing; 200 - Transmission assembly; 300 - First sealing and protection assembly; 400 - Second sealing and protection assembly; 110 - Concave wall; 120 - Upper cover; 130 - Lower cover; 210 - First gear; 220 - Second gear; 230 - First drive shaft; 240 - Second drive shaft; 310 - First sealed bearing; 320 - First shaft end cover; 330 - Second sealed bearing; 410 - Third sealed bearing; 420 - Second shaft end cover; 430 - Fourth sealed bearing; 111 - First plate; 112 - Second plate; 113 - Reinforcing plate. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0019] Currently, traditional gearbox housings have excessively large cavity spaces, occupying significant structural space and resulting in substantial weight, which cannot meet the requirements of heavy-load unmanned helicopters. An embodiment of this application provides a gearbox and drone that, by incorporating a recessed structure on the outer wall of the housing, effectively reduces the redundant cavity space of the second gear chamber, thereby reducing the overall structural space occupied by the housing and achieving a compact gearbox design. Simultaneously, the optimized compression of the cavity space reduces the amount of material used in the housing, significantly lightening the gearbox's own weight and adapting it to the needs of heavy-load unmanned helicopters.

[0020] The specific structure of the gearbox and drone provided in an embodiment of this application will be described in detail below with reference to the accompanying drawings.

[0021] Reference Figures 1-6 As shown, this application embodiment provides a gearbox, including a housing 100; The housing 100 has a first gear cavity and a second gear cavity that are interconnected. A first gear 210 is disposed in the first gear cavity and a second gear 220 is disposed in the second gear cavity. The first gear 210 and the second gear 220 mesh with each other to form the transmission assembly 200 of the gearbox. The housing 100 has a recessed wall 110 facing the second gear 220, at least a portion of which is recessed into the inner side of the second gear cavity, so that the outer wall of the housing 100 forms a recessed structure.

[0022] The gearbox provided in this application includes a housing 100, which serves as the mounting and protective carrier for the transmission assembly 200. It has a first gear cavity and a second gear cavity that are interconnected. A first gear 210 is provided in the first gear cavity, and a second gear 220 is provided in the second gear cavity. The meshing first gear 210 and second gear 220 constitute the gear set of the transmission assembly 200.

[0023] like Figure 3 As shown, the upper horizontal cavity inside the housing 100 is the first gear cavity, and the first gear 210 is horizontally arranged inside the first gear cavity. The vertical cavity on the left is the second gear cavity, and the second gear 220 is vertically arranged inside the second gear cavity.

[0024] The housing 100 has a recessed wall 110 facing the second gear 220, at least a portion of which is recessed into the inner side of the second gear cavity, so that the outer wall of the housing 100 forms a recessed structure. Figure 3 and Figure 4 The concave wall 110 is recessed from the right side of the housing 100 to the left side, and the concave wall 110 is recessed into the second gear cavity on the left side, reducing the space of the second gear cavity, that is, reducing the space inside the entire housing 100.

[0025] This recessed design significantly reduces the internal space of the housing 100 without compromising its structural strength. Compared to traditional gearboxes, it greatly reduces the internal volume and effectively lowers the overall weight of the gearbox, meeting the core requirement of lightweight equipment in the drone industry.

[0026] like Figures 3-5 As shown, in one example, the concave wall 110 is positioned near the bottom of the housing 100.

[0027] The recessed wall 110 is located on one side near the bottom of the housing 100. Figure 4 In this design, the concave wall 110 not only recesses from the right side to the left side of the housing 100, but is also located at the bottom of the housing 100, forming a concave structure at the lower right corner of the housing 100. This allows the width of the second gear cavity on the left side of the housing 100's inner cavity to match that of the second gear 220. Under the influence of gravity, the lubricating oil collects in the second gear cavity, submerging the bottom of the second gear 220. When the second gear 220 rotates, its bottom end is immersed in the lubricating oil, which can carry the lubricating oil up and coat the entire tooth surface. At the same time, through the meshing transmission of the gears, the lubricating oil is transferred to the tooth surface of the first gear 210, achieving sufficient lubrication for the two meshing gears, effectively reducing gear wear, improving transmission efficiency, and solving the problem of low lubricating oil utilization efficiency in traditional gearboxes.

[0028] In one example, the specific shape and structure of the recessed wall 110 can be flexibly designed according to the requirements for adapting to the box space and the structural strength requirements, and it may be as follows: The single L-shaped panel structure is formed by integrally molding mutually perpendicular horizontal and vertical sections. The horizontal section extends laterally along the box body and the vertical section extends longitudinally along the box body. The structure is simple and easy to process, and can quickly form a foundation recessed space. The single arc-shaped plate structure has an inwardly concave arc shape, and the curvature is adapted to the outer contour of the transmission components, which can reduce space occupation and reduce stress concentration. The single trapezoidal plate structure has an inwardly concave trapezoidal shape and sloping transitions on both sides, which takes into account both space reduction and stress distribution. The stepped structure, which is made up of 2-3 straight plates that are parallel or perpendicular to each other, forms a stepped concave area, which can be adapted to complex transmission component layouts. The V-shaped structure, composed of multiple inclined plates, features two plates that curve inward in a V-shape with their apex pointing towards the inner cavity of the box. This design is suitable for scenarios with specific requirements for spatial depth. A combination structure of straight and curved plates, where the horizontal section is a straight plate and the vertical section is a curved plate, or vice versa, combining the stability of straight plates with the low stress advantage of curved plates; The grid-like reinforcement structure adds cross-distributed reinforcing ribs to the recessed base plate to form a grid, which improves the structural rigidity without adding too much weight; the hollowed-out recessed structure opens lightweight hollow holes in the recessed plate to take into account both space optimization and weight reduction requirements, making it suitable for weight-sensitive scenarios. The multi-segment arc splicing structure consists of 2-4 arc plates with different curvatures connected in sequence to form a smooth-transition concave curved surface that perfectly fits the irregular shape of the transmission components. The foldable panel structure is formed by folding a single panel into multiple recessed sections, eliminating the need for additional splicing. It boasts strong overall structural integrity and excellent vibration resistance.

[0029] like Figure 5 As shown, in one example, the concave wall 110 includes a first plate 111 and a second plate 112 that are connected to each other. The first plate 111 is disposed facing the first gear 210, and the second plate 112 is disposed facing the second gear 220, and the first plate 111 and the second plate 112 are disposed at a preset angle; wherein, the distance between the side of the first plate 111 connected to the second plate 112 and the second gear 220 is less than the distance between the side of the first plate 111 away from the second plate 112 and the second gear 220.

[0030] like Figures 2-5 As shown, both the first plate 111 and the second plate 112 can be planar plates. The first plate 111 faces the first gear 210 and is located on the upper part of the second plate 112. The second plate 112 faces the second gear 220 and is located on the left side of the first plate 111. The two are set at a preset angle, which can be 45°-135°.

[0031] Depend on Figures 3-5 It can be seen that the side where the first plate 111 connects to the second plate 112 is the left end of the first plate 111, and the side of the first plate 111 away from the second plate 112 is the right end of the first plate 111. The second gear 220 is located on the left side of the first plate 111. Therefore, the distance between the left end of the first plate 111 and the second gear 220 is less than the distance between the right end of the first plate 111 and the second gear 220. That is, the distance between the side where the first plate 111 connects to the second plate 112 and the second gear 220 is less than the distance between the side of the first plate 111 away from the second plate 112 and the second gear 220.

[0032] One side of the first plate 111 is connected to the box 100, the other side of the first plate 111 is connected to one side of the second plate 112, and the other side of the second plate 112 is connected to the box 100. The connection method can be an integral molding process or welding fixation to ensure the structural strength of the connection part.

[0033] The first plate 111 is located on the side of the second plate 112 that is close to the first gear 210, and the second plate 112 is located on the side of the first plate 111 that is close to the second gear 220. This arrangement ensures that the recessed direction of the concave wall 110 is precisely pointed to the ineffective space inside the housing 100, thereby reducing the volume and avoiding interference with the gear movement trajectory.

[0034] Furthermore, in one example, the first plate 111 is perpendicular to or forms a first angle with the axis of the first gear 210.

[0035] Preferably, the axis of the first plate 111 is perpendicular to the axis of the first gear 210. This can minimize the redundant space inside the housing 100 and make the structural design more compact. However, in the actual production process, a certain deviation may occur, resulting in the first plate 111 and the first gear 210 forming a first angle. The first angle is controlled within a reasonable range, which can be 85°-95°. This can achieve the goal of space reduction while avoiding collision and interference between the first plate 111 and the first gear 210.

[0036] Furthermore, in one instance, the second plate 112 is perpendicular to or forms a second angle with the axis of the second gear 220.

[0037] Preferably, the axis of the second plate 112 is perpendicular to the axis of the second gear 220. This can minimize the redundant space inside the housing 100 and make the structural design more compact. However, in the actual production process, a certain deviation may occur, resulting in the second plate 112 and the second gear 220 forming a second included angle. The second included angle is controlled within a reasonable range, and the angle can be 85°-95°. This can achieve the goal of space reduction while avoiding collision interference between the second plate 112 and the second gear 220.

[0038] Furthermore, in one embodiment, the concave wall 110 also includes a reinforcing plate 113, one side of which is connected to the first plate 111 and the other side is connected to the second plate 112, and the reinforcing plate 113, the first plate 111 and the second plate 112 form a triangular support structure.

[0039] One side of the reinforcing plate 113 is connected to the first plate 111, and the other side is connected to the second plate 112, forming a triangular support structure with the first plate 111 and the second plate 112. The reinforcing plate 113 can be made of the same or equivalent material as the box 100 to ensure support strength; its connection method is welding or integral molding to ensure the firmness of the connection with the first plate 111 and the second plate 112.

[0040] Actual measurements were taken of a conventional gearbox of the same specifications as the gearbox in this application, i.e., the gearbox in this application is adapted to the same power system and the same size bevel gear assembly as the conventional gearbox. The internal volume of the conventional gearbox is 338.3 cm³, while the internal volume of the gearbox provided in this application is only 203.9 cm³, which is 134.4 cm³ less than the conventional gearbox. The volume reduction percentage is 134.4 / 338.3×100%=39.7%. The gearbox provided in this application reduces the internal space by 1 / 3 compared to the conventional gearbox of the same specifications. The conventional transmission weighs 673.9g, while the transmission provided in this application weighs only 467.5g, a reduction of 206.4g (673.9 - 467.5) compared to the conventional transmission. The percentage reduction in weight is 206.4 / 673.9 × 100% = 30.6%. The transmission provided in this application is 1 / 4 lighter than the conventional transmission of the same specifications.

[0041] In one example, the material selection for the housing 100 needs to balance lightweighting, structural strength, and corrosion resistance to meet the aerial operating requirements of unmanned helicopters. Possible materials include: aerospace aluminum alloys (such as 6061-T6 and 7075-T6), which possess high strength and low density, ensuring structural rigidity while reducing weight; magnesium alloys (such as AZ31B), which have a lower density than aluminum alloys, resulting in more significant weight reduction and are suitable for weight-sensitive high-end unmanned helicopters; engineering plastics (such as PA66+glass fiber reinforced and PPS), which have good moldability and corrosion resistance, reducing processing costs and are suitable for medium-to-low load transmission scenarios; stainless steel (such as 304 and 316), which has strong corrosion resistance and is suitable for unmanned helicopters in complex environments such as humid coastal areas or sandstorms; and titanium alloys (such as TC4), which have high strength, are lightweight, and resistant to high and low temperatures, making them suitable for extreme conditions such as high altitudes and low temperatures, but are relatively expensive and are mostly used in unmanned helicopters with special requirements.

[0042] like Figures 1-6 As shown, in one example, both the first gear 210 and the second gear 220 adopt a bevel gear structure design. Compared with traditional straight bevel gears, the bevel gear has a larger tooth surface contact area under the same module of the gear disk, which can give full play to the mechanical performance of the gear and improve the load bearing capacity.

[0043] Reference Figures 7-9 It can be seen that the load comparison experiment between bevel gears and ordinary bevel gears revolves around the power transmission requirements of traditional gearboxes in unmanned helicopters, with the core objective of verifying the performance differences between the two types of gears. Figure 7According to the design parameters, the experiment was set under the unified working conditions of transmitting power P=5kW, pinion speed n1=3000r / min, and stable load without impact. At the same time, it was clarified that the force on the bevel gear tooth surface needs to be decomposed along three orthogonal directions: circumferential force Ft, radial force Fr, and axial force Fa. Among them, the ordinary bevel gear (straight bevel gear) has a line contact form along the tooth width, while the oblique bevel gear has an oblique line contact due to the helix angle β and generates an additional axial force component. This laid the foundation for subsequent force analysis and performance comparison.

[0044] Experiment passed Figure 8 The theoretical calculations were performed using the force formulas in the model, and then verified using force simulation in the gear module of UG software. The final result was obtained. Figure 9 The specific calculation results. From Figure 9 Data shows that the contact stress σH of ordinary bevel gears is approximately 980 MPa, which is close to the allowable value, while the contact stress of tapered bevel gears is reduced to approximately 820 MPa, a decrease of 16%. Under the same module, the load-bearing power of tapered bevel gears is increased by 20%-30% compared to ordinary bevel gears, and the overlap ratio is also improved from approximately 1.0 (instantaneous line contact) of ordinary bevel gears to approximately 1.5-2.0 (multiple teeth meshing simultaneously). In terms of transmission noise, ordinary bevel gears are about 85dB-90dB, while tapered bevel gears are reduced to 70-75dB. Moreover, in heavy-load scenarios, ordinary bevel gears are prone to failure problems such as edge contact, pitting, or galling, while tapered bevel gears can achieve uniform load distribution and have stronger resistance to failure.

[0045] Combination Figure 7 Structural characteristics differences and Figure 9 The experimental results show that the helix angle design of the bevel gear is key to its performance optimization. The helix angle makes the tooth surface contact line an oblique broken line, extending the contact length, which directly corresponds to... Figure 9 The reduction of contact stress and the increase of load-bearing capacity; while Figure 7 The simultaneous meshing characteristic of multiple teeth in the oblique bevel bevel gear mentioned in the text explains... Figure 9 The increased overlap and reduced transmission noise result in a smoother meshing transition, reduced impact vibration, and better suited to the high-speed operating conditions of drones.

[0046] Depend on Figures 7-9 A continuous comparison of data shows that, through structural design optimization, the conical bevel gear is significantly superior to ordinary bevel gears in terms of load-bearing capacity, operational stability, and reliability. It exhibits lower contact stress and higher power load, meeting the high-power transmission requirements of UAVs. Simultaneously, its low noise and strong failure resistance align with the stringent requirements of the aviation industry for gearboxes, providing strong technical support for the structural upgrade of traditional gearboxes in unmanned helicopters.

[0047] like Figures 3-5As shown, in one example, the upper part of the housing 100 is provided with an oil injection hole, which is connected to the first gear cavity or the second gear cavity. The bottom of the housing 100 is provided with an oil drain port, which is connected to the second gear cavity.

[0048] The oil filling hole is located at the top of the housing 100 for easy lubrication. The oil can flow quickly through the connected gear cavity to the meshing parts of the first gear 210 and the second gear 220 for lubrication. The oil drain port is located at the bottom of the housing 100, allowing for complete drainage of old lubricating oil by gravity, preventing residual oil from affecting the lubrication effect of new oil. The positions of the oil filling hole and drain port are designed according to the oil flow pattern, ensuring convenience for lubrication and maintenance operations.

[0049] The rational layout of the oil filling and drain ports makes lubricant filling and replacement convenient, allowing maintenance operations to be completed without disassembling the gearbox, which greatly reduces maintenance costs and downtime.

[0050] like Figure 2 and Figure 3 As shown, in one example, the housing 100 includes a lower cover 130; The lower cover 130 is detachably connected to the bottom of the housing 100, and the oil drain port is located on the lower cover 130.

[0051] The enclosure 100 includes a lower cover 130, which is fixed to the bottom of the enclosure 100 by detachable connectors such as bolts, making the connection firm and easy to disassemble. The oil drain port is located on the lower cover 130. When it is necessary to thoroughly clean the residual oil in the enclosure or to inspect the bottom structure, the lower cover 130 can be removed for full operation, further improving the convenience of maintenance.

[0052] like Figure 2 As shown, the transmission assembly 200 also includes a first transmission shaft 230 and a second transmission shaft 240. The end of the first transmission shaft 230 extends into the housing 100 and is connected to the first gear 210; the end of the second transmission shaft 240 extends into the housing 100 and is connected to the second gear 220.

[0053] like Figure 2 and Figure 3 As shown, in one example, the housing 100 also includes a top cover 120; The top cover 120 is detachably attached to the top of the housing 100. The top cover 120 is made of a material that matches the housing 100 and can be detachably attached by bolts or other connecting parts, making it easy to open the housing 100 to inspect, maintain or replace the internal transmission components 200.

[0054] The housing 100 is provided with a second shaft hole, which is rotatably engaged with the second drive shaft 240 of the transmission assembly 200; the upper cover 120 is provided with a first shaft hole, which is rotatably engaged with the first drive shaft 230 of the transmission assembly 200.

[0055] like Figure 2 As shown, in one embodiment, a first sealing and protective assembly 300 is also included. The first sealing and protective assembly 300 includes a first sealing bearing 310, which is disposed in the second shaft hole of the housing 100. The inner wall of the first sealing bearing 310 is interference-fitted with the second drive shaft 240. The first sealing bearing 310 adopts a double-sided sealing structure and has built-in grease, which can reduce the frictional resistance when the second drive shaft 240 rotates, prevent the lubricating oil in the housing from leaking out, and prevent external dust and moisture from entering the housing, thus ensuring the stable operation of the transmission assembly and adapting to the complex aerial operating conditions of unmanned helicopters.

[0056] Furthermore, in one embodiment, the first sealing and protective assembly 300 also includes a first shaft end cover 320. The first shaft end cover 320 is flared, with its wide end fixed to the outer wall of the housing 100 by bolts and coaxially arranged with the second shaft hole. The second drive shaft 240 passes through the narrow end of the first shaft end cover 320, and a reasonable gap is reserved between the inner wall of the cover and the second drive shaft 240 to avoid rotational interference. The first shaft end cover 320 can provide secondary protection for the first sealed bearing 310, blocking external foreign objects from directly impacting the bearing, while reducing the direct blowing of airflow onto the bearing, reducing the evaporation rate of lubricating grease, and extending the service life of the sealed bearing.

[0057] Furthermore, in one embodiment, the first sealing and protective assembly 300 also includes a second sealing bearing 330. The second sealing bearing 330 is disposed inside the narrow end of the first shaft end cover 320, with its outer wall interference-fitted to the inner wall of the narrow end of the first shaft end cover 320, and its inner wall clearance-fitted to the second drive shaft 240. The second sealing bearing 330 and the first sealing bearing 310 are distributed axially along the second drive shaft 240, forming a double sealing and protective structure, further improving the sealing effect. Even if the first sealing bearing 310 experiences slight leakage, the second sealing bearing 330 can prevent lubricating oil leakage, while also enhancing the support stability of the first drive shaft 230 and reducing radial runout during high-speed rotation.

[0058] like Figure 2 and Figure 3As shown, in one embodiment, a second sealing and protective assembly 400 is also included. The second sealing and protective assembly 400 includes a third sealing bearing 410, which is disposed in the first shaft hole of the upper cover 120. The inner wall of the third sealing bearing 410 is interference-fitted with the first transmission shaft 230. The third sealing bearing 410 adopts a high-speed sealing design to meet the vertical high-speed rotation requirements of the first transmission shaft 230. It can ensure smooth rotation, seal the gap at the top of the housing to prevent lubricating oil from leaking from the first shaft hole, and isolate impurities in the external environment to avoid contaminating the lubricating oil and transmission components inside the housing.

[0059] Furthermore, in one embodiment, the second sealing protection assembly 400 also includes a second shaft end cover 420. The second shaft end cover 420 is shaped like an inverted trumpet, with its wide end fixed to the top outer wall of the upper cover 120 by bolts and coaxially arranged with the first shaft hole. The first drive shaft 230 passes through the narrow end of the second shaft end cover 420, and the inner side of the cover is in contact with the top of the third sealed bearing 410, forming a closed protective space. The second shaft end cover 420 can provide physical protection for the third sealed bearing 410, preventing falling objects from high altitudes and particles carried by airflow from impacting the bearing, while reducing direct contact between rainwater and dew and the bearing, delaying bearing corrosion and aging, and adapting to the complex environment of unmanned helicopter outdoor flight.

[0060] Furthermore, in one embodiment, the second sealing and protective assembly 400 also includes a fourth sealing bearing 430. The fourth sealing bearing 430 is disposed inside the narrow end of the second shaft end cover 420, with its outer wall interference-fitted with the inner wall of the narrow end of the second shaft end cover 420, and its inner wall clearance-fitted with the first drive shaft 230. The fourth sealing bearing 430 and the third sealing bearing 410 are correspondingly distributed vertically along the axial direction of the first drive shaft 230, forming a double sealing support structure. This not only improves the coaxiality and stability of the first drive shaft 230 during high-speed rotation, but also further enhances the sealing effect, effectively preventing lubricating oil leakage and external impurities from intruding, ensuring reliable operation of the gearbox under long-term, high-load conditions.

[0061] In one example, this application also provides a drone, which includes the gearbox described above.

[0062] This drone can be classified as an unmanned helicopter. The gearbox, as a core power transmission component, is installed between the drone's power system and propeller drive mechanism. It converts the high-speed output of the engine into high torque, providing stable power for the drone's takeoff and flight. The gearbox features a lightweight design that improves the drone's payload ratio, a bevel gear structure that enhances power transmission stability and load-bearing capacity, and a convenient maintenance design that reduces the drone's operating costs. The overall structure meets the stringent requirements of unmanned helicopters in the aviation field for lightweight, safe, and reliable equipment.

[0063] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0065] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0066] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "exemplary embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0067] It is readily understood that, based on the several embodiments provided in this application, those skilled in the art can combine, split, or reorganize the embodiments of this application to obtain other embodiments, none of which exceed the protection scope of this application.

[0068] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A gearbox, characterized in that: Includes the enclosure (100); The housing (100) has a first gear cavity and a second gear cavity that are interconnected. A first gear (210) is disposed in the first gear cavity and a second gear (220) is disposed in the second gear cavity. The first gear (210) and the second gear (220) mesh with each other to form the transmission assembly (200) of the gearbox. The housing (100) has a recessed wall (110) facing the second gear (220), at least a portion of which is recessed into the inner side of the second gear cavity, so that the outer wall of the housing (100) forms a recessed structure.

2. The gearbox according to claim 1, characterized in that: The concave wall (110) is located near the bottom of the box body (100).

3. The gearbox according to claim 1, characterized in that: The concave wall (110) includes a first plate (111) and a second plate (112) that are connected to each other. The first plate (111) is disposed facing the first gear (210), and the second plate (112) is disposed facing the second gear (220), and the first plate (111) and the second plate (112) are disposed at a preset angle; wherein, the distance between the side of the first plate (111) connected to the second plate (112) and the second gear (220) is less than the distance between the side of the first plate (111) away from the second plate (112) and the second gear (220).

4. The gearbox according to claim 3, characterized in that: The first plate (111) is perpendicular to or forms a first angle with the axis of the first gear (210).

5. The gearbox according to claim 3, characterized in that: The second plate (112) is perpendicular to or at a second angle to the axis of the second gear (220).

6. The gearbox according to claim 3, characterized in that: The concave wall (110) also includes a reinforcing plate (113), one side of which is connected to the first plate (111) and the other side is connected to the second plate (112), and the reinforcing plate (113) forms a triangular support structure with the first plate (111) and the second plate (112).

7. The gearbox according to claim 3, characterized in that: The upper part of the housing (100) is provided with an oil injection hole, which is connected to the first gear cavity or the second gear cavity; The bottom of the housing (100) is provided with an oil drain port, which is connected to the second gear cavity.

8. The gearbox according to claim 7, characterized in that: The housing (100) includes a lower cover (130); The lower cover (130) is detachably connected to the bottom of the box (100), and the oil drain port is opened on the lower cover (130).

9. The gearbox according to claim 8, characterized in that: The housing (100) also includes a top cover (120); The top cover (120) is detachably fitted onto the top of the housing (100). The top cover (120) is provided with a first shaft hole, which engages with the first drive shaft of the transmission assembly (200).

10. An unmanned aerial vehicle (UAV), characterized in that: Includes the gearbox as described in any one of claims 1-9.

Images