Speed reducer and method for shielding type electric driving device

Abstract

The invention relates to a speed reducer and method for a shielding type electric driving device, and belongs to the technical field of speed reducers. Comprising a shell, an integrated inner gear ring assembly is arranged in the shell, a first-stage compact type planet wheel and a second-stage compact type planet wheel are arranged in the integrated inner gear ring assembly, a uniform load compensation assembly is arranged in the shell, and a lubrication cooperation assembly is arranged in the shell; the integrated inner gear ring assembly and the shell are in interference fit, and the integrated inner gear ring assembly is used for eliminating the coaxiality deviation of the split type inner gear ring; the uniform load compensation assembly is used for homogenizing load distribution of the first-stage compact planet wheel and the second-stage compact planet wheel under the large transmission ratio. The device is compact in structure, high in coaxiality, uniform in load distribution, reliable in lubrication, capable of achieving large-transmission-ratio speed reduction in a narrow space, excellent in transmission precision and rigidity and adaptive to the working condition of a shielding type electric driving device.

Description

Technical Field

[0001] This invention relates to the field of speed reducer technology, and in particular to a speed reducer and method for a shielded electric drive device. Background Technology

[0002] Planetary reducers are power transmission mechanisms based on involute planetary gear transmission technology. They achieve speed reduction by having multiple planetary gears rotate around a sun gear. They are characterized by light weight, small size, and a wide transmission ratio range. Their installation methods include foot mounting, flange mounting, and torque arm mounting. Precision planetary reducers belong to this type and are characterized by high precision and strong stability. The coaxial planetary gear reducer has achieved mass production for the first time in the world, improving transmission efficiency while reducing size and weight. It is mainly used in high-end manufacturing fields such as robotics, new energy equipment, and high-end machine tools.

[0003] Existing planetary gear reducers for shielded valve electric drive devices still have many technical defects in practical applications, making it difficult to adapt to the operating conditions of the equipment. The main problems are as follows: First, under the dual constraints of limited installation space and large transmission ratio, traditional planetary gear transmission structures cannot balance strength, load-bearing capacity, and transmission smoothness. Equidistantly arranged planetary gears are prone to uneven load distribution, and individual planetary gears may overload mesh, leading to accelerated tooth surface wear, high transmission noise, and a significant reduction in the reducer's service life. Second, traditional two-stage planetary gear systems often adopt a split internal gear ring structure. The spliced ​​design is prone to coaxiality deviation, and the assembly process is complex, resulting in a large radial dimension. At the same time, the connection rigidity of the split structure is also limited. The existing reducers suffer from several drawbacks. First, insufficient lubrication leads to problems such as radial runout and circumferential slippage of the internal gear ring during transmission, resulting in a decrease in overall rigidity and operational reliability. Second, the lubrication structure of the existing reducers is poorly designed, leading to problems such as heat accumulation in the lubricating oil and high oil stirring resistance in the confined space. Furthermore, there are many lubrication blind spots, insufficient lubrication of the meshing surfaces and moving pairs, and the lack of an effective self-lubricating structure on the mating surfaces of the planetary gears and planetary shafts, which can easily cause jamming. Third, some reducers use multiple connecting parts for their transmission components, resulting in clearances. This can easily cause vibration and power loss during torque transmission. In addition, the unreasonable input and output layout design further increases the space occupied by the reducer, making it unsuitable for the compact installation requirements of shielded electric drive devices.

[0004] Therefore, this application provides a speed reducer and method for a shielded electric drive device to meet the requirements. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a reducer and method for a shielded electric drive device, so as to solve the problems of poor coaxiality, complex assembly, large radial dimensions, insufficient rigidity and reliability of the whole machine, and difficulty in simultaneously meeting the requirements of strength, load-bearing capacity, transmission smoothness and structural compactness.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A reducer for a shielded electric drive device includes a housing, an integrated internal gear ring assembly housed inside the housing, a first-stage compact planetary gear and a second-stage compact planetary gear housed inside the integrated internal gear ring assembly, a load-sharing compensation component housed inside the housing, and a lubrication coordination component housed inside the housing; the integrated internal gear ring assembly is interference-fitted with the housing, the integrated internal gear ring assembly is used to eliminate coaxiality deviation of the split internal gear ring; the load-sharing compensation component is used to equalize the load distribution of the first-stage compact planetary gear and the second-stage compact planetary gear under high transmission ratios; the lubrication coordination component is used to ensure the long-term reliable operation of the integrated internal gear ring assembly.

[0007] Optionally, an input end is provided on one side of the housing, the input end being located on the same side as the first-stage compact planetary gear, and a flat key adapted to an external motor is embedded inside the input end. An output end is provided on the other side of the housing, the output end being located on the same side as the second-stage compact planetary gear, and the output end is designed with an internal spline. The housing adopts an integrated die-cast aluminum alloy design, and reinforcing ribs are provided on the housing.

[0008] Optionally, the inner wall of the integrated internal gear ring assembly is provided with a primary internal gear surface and a secondary internal gear surface. The primary internal gear surface is meshed with a primary compact planetary gear, and the secondary internal gear surface is meshed with a secondary compact planetary gear. An integrated annular spacer is provided between the two levels of internal gear surfaces of the integrated internal gear ring assembly.

[0009] Optionally, the first-stage compact planetary gear includes a first-stage sun gear, the teeth of which are integrally forged with the motor input end. The first-stage sun gear is meshed with three first-stage planetary gears, each of which meshes with a first-stage internal tooth surface. Each first-stage planetary gear is mounted on a first-stage planetary shaft, and the first-stage planetary shafts are all fixedly connected to the same first-stage planetary carrier. A transition output shaft is provided at the center of the first-stage planetary carrier, and the transition output shaft is integrally forged with the first-stage planetary carrier.

[0010] Optionally, the secondary compact planetary gear includes a secondary sun gear, the inner bore of which is connected to the transition output shaft. The secondary sun gear is meshed with three secondary planetary gears, each of which meshes with a secondary internal tooth surface. Each secondary planetary gear is mounted on a secondary planetary shaft, and the secondary planetary shafts are all fixedly connected to the same secondary planetary carrier. The center position of the secondary planetary carrier is adapted to the output end of the housing. The internal splines of the secondary planetary carrier cooperate with the internal splines of the output end to achieve torque output.

[0011] Optionally, the three first-stage planetary gears and the three second-stage planetary gears are arranged asymmetrically, and the included angles of the three planetary gears in each planetary gear set are set to 118°, 120° and 122°, respectively.

[0012] Optionally, the load-sharing compensation component includes an elastic floating bushing and a brass eccentric self-aligning bushing. The elastic floating bushing is disposed between the secondary sun gear and the transition output shaft. The elastic floating bushing is interference-fitted with the transition output shaft and clearance-fitted with the inner hole of the secondary sun gear.

[0013] Optionally, the brass eccentric self-aligning bushing is disposed between each planetary gear and the planetary shaft. The brass eccentric self-aligning bushing is nested in the outer circle of the copper-based solid self-lubricating bearing. The inner hole of the copper-based solid self-lubricating bearing is sleeved on the planetary shaft. A double-row needle roller bearing is coaxially sleeved on the outer side of the brass eccentric self-aligning bushing. The inner ring of the double-row needle roller bearing is clearance-fitted with the outer circle of the brass eccentric self-aligning bushing, and the outer ring is interference-fitted with the inner hole of the planetary gear. Micron-level micropores are machined on the outer ring of the double-row needle roller bearing, and the micropores are impregnated with molybdenum disulfide lithium-based grease.

[0014] Optionally, the lubrication coordination component includes a micro oil sump, which is disposed on the inner wall of the bottom of the housing, in the area below the outer side of the integrated internal gear ring assembly. The bottom wall of the integrated internal gear ring assembly has an oil outlet notch at the position corresponding to the primary internal gear surface and the secondary internal gear surface. The integrated annular spacer has guide oil grooves on both sides, and the integrated annular spacer has an oil return notch at the bottom. The housing is provided with a metering oil injection nozzle.

[0015] The present invention also provides another technical solution: a method for using a reducer for a shielded electric drive device, the method comprising the following steps: S1. Connect the output shaft of the external motor to the input end of the reducer housing. A rigid torque connection between the motor and the first-stage sun gear is achieved through the flat key inside the input end. The rotation of the motor drives the first-stage sun gear to rotate synchronously. S2. The first-stage sun gear drives the three first-stage planetary gears to rotate. Because the first-stage planetary gears mesh with the first-stage internal tooth surface of the integrated internal gear ring assembly, they drive the first-stage planetary carrier to revolve, completing the first-stage reduction. The torque is transmitted to the second-stage sun gear through the transition output shaft. S3, the second-stage sun gear drives the three second-stage planetary gears to rotate, the second-stage planetary gears mesh with the second-stage internal tooth surface of the integrated internal gear ring assembly, driving the second-stage planetary carrier to revolve, completing the second-stage reduction, and the torque is amplified again and output through the internal spline; S4. The load sharing compensation component forms a dual load sharing mechanism during the transmission process through the passive radial floating of the elastic floating bushing and the active self-aligning of the brass eccentric self-aligning bushing, which adjusts the meshing position in real time to ensure that the meshing load borne by each planetary gear is evenly distributed. S5. The lubrication coordination component stores oil in a micro oil tank. The planetary gear picks up lubricating oil from the oil outlet and guides it to the meshing surface through the guide oil groove. The unabsorbed lubricating oil flows back to the micro oil tank through the return oil outlet, forming a closed-loop lubrication system.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: In the above solution, by setting an integrated internal gear ring assembly, the primary internal gear surface, the secondary internal gear surface and the integrated annular spacer are integrated as a whole, which completely eliminates the coaxiality deviation of the split structure, improves the meshing accuracy, avoids tooth surface wear, and improves the connection rigidity by interference fit with the housing, eliminating radial movement and circumferential slippage. The integrated spacer replaces the independent spacer sleeve, simplifies the assembly and realizes precise axial positioning of the planetary gear. The bottom oil outlet, the spacer guide oil groove and the return oil outlet provide directional channels for the lubrication system, realize the circulation of lubricating oil and eliminate lubrication blind spots.

[0017] By setting up a load-sharing compensation component, the elastic floating bushing achieves radial micro-floating of the secondary sun gear, automatically compensating for machining and assembly errors, passively equalizing the secondary load, and the brass eccentric self-aligning bushing can be manually aligned, forming a dual load-sharing system with the floating bushing, which is both active and passive, keeping the load deviation low. The copper-based solid self-lubricating bearing provides oil-free self-lubrication for the mating surfaces, avoiding heat accumulation and jamming. The double-row needle roller bearing provides stable radial support for the planetary gears, and the microporous grease on the outer ring achieves self-lubrication, complementing the solid self-lubricating bearing, ensuring that the component operates flexibly and has a strong load-bearing capacity.

[0018] By incorporating a lubrication coordination component, the miniature oil sump utilizes the outer shell cavity to store oil. The outer layout prevents heat buildup from oil churning in the inner ring, precisely controlling the oil level and balancing lubrication and transmission resistance. The oil outlet provides a channel for lubricating oil to enter the meshing area, and the circumferential distribution ensures uniform oil supply. The spiral guide oil groove precisely guides the lubricating oil to the meshing surface, eliminating blind spots and increasing contact time. The return oil outlet enables lubricating oil circulation and return, reducing losses and preventing heat buildup. The metering nozzle facilitates precise oil filling and subsequent oil level checks. The sealing design prevents contamination and leakage, simplifying maintenance. Attached Figure Description

[0019] Figure 1 A three-dimensional structural diagram of a speed reducer used in a shielded electric drive device; Figure 2 A cross-sectional view of a speed reducer used in a shielded electric drive system; Figure 3 A cross-sectional view of the integrated internal gear ring assembly; Figure 4 A schematic diagram of a single-stage compact planetary gear structure; Figure 5 This is a cross-sectional view of the input terminal and the first-stage sun gear; Figure 6A cross-sectional view of a two-stage compact planetary gear; Figure 7 for Figure 3 Enlarged schematic diagram of the structure at point B in the diagram; Figure 8 This is a schematic diagram of the three-dimensional structure of the load-sharing compensation component; Figure 9 for Figure 2 Enlarged schematic diagram of the structure at point A in the diagram; Figure 10 This is a top view of a speed reducer used in a shielded electric drive system.

[0020] Figure label: 1. Housing; 101. Input end; 102. Output end; 103. Flat key; 104. Internal spline; 105. Reinforcing rib; 2. Integrated internal gear ring assembly; 201. Primary internal gear surface; 202. Secondary internal gear surface; 203. Integrated annular spacer; 3. Primary compact planetary gear; 301. Primary sun gear; 302. Primary planetary gear; 303. Primary planetary shaft; 304. Primary planetary carrier; 305. Transition output shaft; 4. Secondary compact planetary gear; 401. Second-stage sun gear; 402. Second-stage planetary gear; 403. Second-stage planetary shaft; 404. Second-stage planetary carrier; 5. Load sharing compensation assembly; 501. Elastic floating bushing; 502. Copper-based solid self-lubricating bearing; 503. Brass eccentric self-aligning bushing; 504. Double-row needle roller bearing; 505. Micro-orifice; 6. Lubrication coordination assembly; 601. Micro oil sump; 602. Oil outlet notch; 603. Guide oil groove; 604. Oil return notch; 605. Metering oil injection nozzle. Detailed Implementation

[0021] To further illustrate the technical means and effects adopted by the present invention in order to achieve the intended purpose, the following detailed description is provided in conjunction with the accompanying drawings and preferred embodiments, based on the specific implementation methods, structures, features and effects of the present invention.

[0022] like Figures 1 to 10As shown, an embodiment of the present invention provides a reducer for a shielded electric drive device, including a housing 1, an integrated internal gear ring assembly 2 disposed inside the housing 1, a first-stage compact planetary gear 3 and a second-stage compact planetary gear 4 disposed inside the integrated internal gear ring assembly 2, a load sharing compensation component 5 disposed inside the housing 1, and a lubrication coordination component 6 disposed inside the housing 1. The integrated internal gear ring assembly 2 and the housing 1 are interference-fitted. The integrated internal gear ring assembly 2 is used to eliminate the coaxiality deviation of the split internal gear ring, the load sharing compensation component 5 is used to equalize the load distribution of the first-stage compact planetary gear 3 and the second-stage compact planetary gear 4 under a large transmission ratio, and the lubrication coordination component 6 is used to ensure a smooth transmission. The integrated internal gear ring assembly 2 ensures long-term reliable operation by interfering with the housing 1, eliminating the coaxiality deviation problem of traditional split internal gear rings at the structural root. This solves the problems of low transmission accuracy and meshing wear caused by insufficient coaxiality in the reducer. At the same time, the integrated load sharing compensation component 5 and lubrication coordination component 6 are designed to address the pain points of uneven load under high transmission ratios and lubrication pain points for long-term operation of the integrated structure, respectively. The three core components work together to allow the reducer to meet the requirements of high transmission ratio, high transmission accuracy, and strong load-bearing capacity in a small installation space, thereby improving the overall structural compactness and operational reliability of the reducer.

[0023] like Figures 1 to 2 As shown, an input terminal 101 is provided on one side of the housing 1, and the input terminal 101 is located on the same side as the first-stage compact planetary gear 3. A flat key 103 adapted to the external motor is embedded inside the input terminal 101. An output terminal 102 is provided on the other side of the housing 1, and the output terminal 102 is located on the same side as the second-stage compact planetary gear 4. The output terminal 102 is designed with an internal spline 104. The housing 1 adopts an integrated die-cast aluminum alloy design and is provided with reinforcing ribs 105. The integrated die-cast aluminum alloy design of the housing 1 combines lightweight and structural rigidity. The addition of reinforcing ribs 105 on the outside further improves the deformation resistance of the housing 1 without increasing the radial dimension, and is compatible with shielded electric drives. The device is designed for confined installation conditions and requires high torque transmission. The input end 101 is embedded with a flat key 103 to achieve precise and reliable torque connection with an external motor, resulting in small transmission clearance and high torque transmission efficiency. The output end 102 is designed with an internal spline 104 and is arranged on the same side as the two-stage compact planetary gear 4, realizing direct internal meshing connection between the reducer and the actuator. This eliminates redundant components such as the extended output shaft, significantly compressing the radial space of the reducer. At the same time, the internal spline 104 helps to improve the stability of torque output and connection rigidity. The corresponding arrangement of the input and output ends 102 and the two-stage planetary gears on the same side optimizes the internal power transmission path of the reducer, reduces power loss, and improves overall transmission efficiency.

[0024] like Figure 3As shown, the integrated internal gear ring assembly 2 has a primary internal gear surface 201 and a secondary internal gear surface 202 on its inner wall. The primary internal gear surface 201 is meshed with a primary compact planetary gear 3, and the secondary internal gear surface 202 is meshed with a secondary compact planetary gear 4. An integrated annular spacer 203 is provided between the two levels of internal gear surfaces of the integrated internal gear ring assembly 2. The integrated internal gear ring assembly 2 integrates the primary internal gear surface 201, the secondary internal gear surface 202, and the integrated annular spacer 203. The two levels of internal gear surfaces, which are formed in one piece, ensure extremely high coaxiality, completely solving the problem of traditional To address the issues of complex assembly and poor coaxiality in split-type internal gear rings, this design improves the meshing accuracy of the two-stage planetary gear system and reduces tooth surface wear. The integrated annular spacer 203 and the internal gear ring assembly are a single unit, eliminating the need for additional spacers. This simplifies the assembly process and avoids the assembly errors associated with independent spacers. It also enables precise axial positioning of the first and second stage planetary gears, preventing poor meshing caused by axial movement of the planetary gears. The integrated structural design allows for a closer fit between the internal gear ring assembly and the housing 1, improving the overall structural rigidity of the reducer and reducing vibration and noise during transmission.

[0025] like Figures 4 to 5 As shown, the first-stage compact planetary gear 3 includes a first-stage sun gear 301. The teeth of the first-stage sun gear 301 are integrally forged with the motor input end 101. The first-stage sun gear 301 is meshed with three first-stage planetary gears 302. Each first-stage planetary gear 302 meshes with the first-stage internal tooth surface 201. Each first-stage planetary gear 302 is mounted on a first-stage planetary shaft 303. The first-stage planetary shafts 303 are all fixedly connected to the same first-stage planetary carrier 304. A transition output shaft 305 is located at the center of the first-stage planetary carrier 304. The transition output shaft 305 is integrally forged with the first-stage planetary carrier 304. The teeth of the first-stage sun gear 301 and the motor input end 101 are integrally forged, eliminating the connecting parts between them. This improves transmission rigidity from the power input source and avoids torque transmission loss and vibration caused by gaps in the connecting parts, making it suitable for high torque input conditions. The transition output shaft 305 and the first-stage planetary carrier 304 are integrally forged, reducing the intermediate connecting parts that transmit power from the first-stage planetary carrier 304 to the second-stage sun gear 401, improving the transmission rigidity and torque transmission efficiency of the transition section. At the same time, the integrated structure ensures the coaxiality of the transition output shaft 305 and the first-stage planetary carrier 304, laying the foundation for the precise meshing of the second-stage planetary gear system.

[0026] like Figure 6As shown, the second-stage compact planetary gear 4 includes a second-stage sun gear 401. The inner bore of the second-stage sun gear 401 is connected to the transition output shaft 305. The second-stage sun gear 401 is meshed with three second-stage planetary gears 402. Each second-stage planetary gear 402 meshes with the second-stage internal tooth surface 202. Each second-stage planetary gear 402 is mounted on a second-stage planetary shaft 403. The second-stage planetary shafts 403 are all fixedly connected to the same second-stage planetary carrier 404. The center position of the second-stage planetary carrier 404 is adapted to the output end 102 of the outer casing 1. The internal spline 104 of the second-stage planetary carrier 404 cooperates with the internal spline 104 of the output end 102 to achieve torque output. The three first-stage planetary gears 302 and the three second-stage planetary gears 402 are all arranged asymmetrically. The three planetary gears of each planetary gear set... With included angles set at 118°, 120°, and 122° respectively, the second-stage planetary gear train connects with the first-stage planetary gear train to form a two-stage reduction structure, meeting the high transmission ratio requirements of the shielded electric drive device. The center of the second-stage planetary carrier 404 is adapted to the output end 102 of the outer casing 1, and torque output is achieved through the internal spline 104. The connection method is compact and the torque transmission is reliable, adapting to the assembly and use requirements of narrow spaces. The three first-stage and second-stage planetary gears 402 all adopt an asymmetrical arrangement of 118°, 120°, and 122°, breaking the problem of uneven load distribution caused by the traditional equidistant arrangement, making the meshing load of each planetary gear more uniform, avoiding overload meshing of individual planetary gears, improving the overall load-bearing capacity and service life of the planetary gear train, and reducing meshing impact caused by uneven load, thus improving transmission smoothness.

[0027] like Figures 7 to 8As shown, the load-sharing compensation component 5 includes an elastic floating bushing 501 and a brass eccentric self-aligning bushing 503. The elastic floating bushing 501 is disposed between the secondary sun gear 401 and the transition output shaft 305. The elastic floating bushing 501 is interference-fitted with the transition output shaft 305, and clearance-fitted with the inner hole of the secondary sun gear 401. The brass eccentric self-aligning bushing 503 is disposed between each planetary gear and the planetary shaft. The brass eccentric self-aligning bushing 503 is nested on the outer circle of the copper-based solid self-lubricating bearing 502. A solid self-lubricating bearing 502 is fitted onto the planetary shaft. A double-row needle roller bearing 504 is coaxially fitted onto the outer side of a brass eccentric self-aligning bushing 503. The inner ring of the double-row needle roller bearing 504 has a clearance fit with the outer circle of the brass eccentric self-aligning bushing 503, while the outer ring has an interference fit with the inner bore of the planetary gear. Micron-sized micropores 505 are machined on the outer ring of the double-row needle roller bearing 504, and the micropores 505 are impregnated with lithium molybdenum disulfide grease. An elastic floating bushing 501 is positioned between the secondary sun gear 401 and the transition output shaft 305, with both interference and clearance fits. The combined design allows the second-stage sun gear 401 to achieve minute radial floating, automatically compensating for minor machining and assembly errors in the second-stage planetary gear train, adjusting the meshing position, and further homogenizing the load distribution of the second-stage planetary gears 402. The brass eccentric self-aligning bushing 503 and the copper-based solid self-lubricating bearing 502 form a coaxial nested structure. The eccentric self-aligning bushing allows for manual adjustment of the radial position of the planetary gears, achieving active self-alignment and load sharing. Together with the elastic floating bushing 501, this forms a dual load-sharing mechanism of active self-alignment and passive floating, further balancing the meshing of the planetary gears. The load deviation is controlled within a low range, which greatly improves the load-bearing capacity of the reducer. The copper-based solid self-lubricating bearing 502 provides oil-free self-lubrication for the mating surfaces of the planetary gear and the planetary shaft. The micron-level micropores 505 of the outer ring of the double-row needle roller bearing 504 are impregnated with grease to achieve self-lubrication of the bearing. The combination of the two avoids the problem of heat accumulation and jamming of lubricating oil in a narrow space. At the same time, the clearance fit and interference fit design of the double-row needle roller bearing 504 ensures the flexible operation and connection rigidity of the planetary gear, and improves the operational reliability of the load sharing compensation component 5.

[0028] like Figures 9 to 10As shown, the lubrication coordination component 6 includes a miniature oil sump 601, which is located on the inner bottom wall of the housing 1, in the area below the outer side of the integrated internal gear ring assembly 2. The bottom wall of the integrated internal gear ring assembly 2 has an oil outlet 602 corresponding to the positions of the primary internal gear surface 201 and the secondary internal gear surface 202. The integrated annular spacer 203 has guide oil grooves 603 on both sides, and an oil return sump 604 at the bottom of the integrated annular spacer 203. A metering oil nozzle 605 is provided on the housing 1. The miniature oil sump 601, located on the inner bottom wall of the housing 1 and below the outer side of the integrated internal gear ring assembly 2, utilizes the cavity of the housing 1 to store lubricating oil while avoiding problems such as high resistance to oil churning and severe heat accumulation caused by placing the oil sump inside the internal gear ring. This adapts to the lubrication layout requirements of confined spaces. The oil outlet 602 at the bottom of the integrated internal gear ring assembly 2 is for lubrication... The system provides a channel for oil to enter the meshing area. When the planetary gears rotate, they can pick up the lubricating oil in the oil sump to achieve splash lubrication. The guide oil groove 603 of the integrated annular spacer 203 can accurately guide the lubricating oil to the meshing parts of the first and second stage internal gear surfaces 202, eliminating lubrication blind spots, improving the lubrication effect of the gear surfaces, and reducing gear surface wear. The return oil notch 604 realizes the circulation and return of lubricating oil, avoiding the accumulation of lubricating oil in the meshing area and reducing oil loss. The metering oil nozzle 605 on the outer shell 1 facilitates accurate addition of lubricating oil, ensuring a reasonable oil level, which not only meets the lubrication requirements but also avoids the oil stirring resistance and heat accumulation caused by excessive oil level. The entire lubrication coordination component 6 forms a closed-loop lubrication system of oil storage, oil supply, oil guidance, and oil return, providing continuous and precise lubrication guarantee for the integrated internal gear ring component 2 and planetary gear system, effectively extending the service life of the reducer and ensuring the long-term reliable operation of the integrated structure.

[0029] The present invention also provides another technical solution: a method for using a reducer for a shielded electric drive device, the method comprising the following steps: S1. Connect the output shaft of the external motor to the input end 101 of the reducer housing 1. A rigid torque connection between the motor and the first-stage sun gear 301 is achieved through the flat key 103 inside the input end 101. The rotation of the motor drives the first-stage sun gear 301 to rotate synchronously.

[0030] S2. The first-stage sun gear 301 drives the three first-stage planetary gears 302 to rotate. Because the first-stage planetary gears 302 mesh with the first-stage internal tooth surface 201 of the integrated internal gear ring assembly 2, they drive the first-stage planetary carrier 304 to revolve, completing the first-stage reduction. The torque is transmitted to the second-stage sun gear 401 through the transition output shaft 305.

[0031] S3, the second-stage sun gear 401 drives the three second-stage planetary gears 402 to rotate. The second-stage planetary gears 402 mesh with the second-stage internal tooth surface 202 of the integrated internal gear ring assembly 2, driving the second-stage planetary carrier 404 to revolve, completing the second-stage reduction, and the torque is amplified again and output through the internal spline 104.

[0032] S4. The load sharing compensation component 5 forms a dual load sharing mechanism during the transmission process through the passive radial floating of the elastic floating bushing 501 and the active self-aligning of the brass eccentric self-aligning bushing 503, which adjusts the meshing position in real time to ensure that the meshing load borne by each planetary gear is evenly distributed.

[0033] S5. The lubrication coordination component 6 stores oil through the micro oil tank 601. The planetary gear picks up lubricating oil from the oil outlet 602 and guides it to the meshing surface through the guide oil groove 60. The unabsorbed lubricating oil flows back to the micro oil tank 601 through the return oil outlet 604, forming a closed-loop lubrication system.

[0034] The working principle of the technical solution provided by this invention is as follows: This reducer is a two-stage compact planetary gear reducer. It uses an integrated internal gear ring assembly 2 as the fixed meshing base and achieves speed reduction and torque increase through the first and second stage planetary gear trains. With the help of the load sharing compensation assembly 5, the meshing load distribution is optimized in real time. The lubrication coordination assembly 6 provides precise closed-loop lubrication throughout the process. The whole system achieves high transmission ratio, high precision, and high reliability torque transmission in a small space through the transmission path of power input, two-stage reduction and torque output. It is suitable for the working conditions of shielded electric drive devices. Through the three core parts of power transmission, load sharing compensation and lubrication guarantee, the various systems work together.

[0035] The output shaft of the external motor is connected to the input end 101 of the reducer housing 1. A rigid torque connection between the motor and the first-stage sun gear 301 is achieved via a key 103 within the input end 101. The rotation of the motor drives the first-stage sun gear 301 to rotate synchronously. The first-stage sun gear 301 is the power input driving element. The rotation of the first-stage sun gear 301 drives the three first-stage planetary gears 302 meshing with it to rotate around it. Because the first-stage planetary gears 302 simultaneously mesh with the first-stage internal gear surface 201 of the integrated internal gear ring assembly 2, and the first-stage internal gear... With tooth surface 201 fixed, the rotating first-stage planetary gear 302, driven by the meshing reaction force, propels the first-stage planetary carrier 304 to revolve around the center of the first-stage sun gear 301, completing the first-stage reduction. The revolution speed of the first-stage planetary carrier 304 is much lower than the rotation speed of the first-stage sun gear 301, resulting in synchronous torque amplification. The power is then transmitted to the transition output shaft 305, which is integrally forged with the first-stage planetary carrier 304. The transition output shaft 305 revolves synchronously with the first-stage planetary carrier 304, seamlessly transmitting the torque after the first-stage reduction to the second-stage sun gear 4. 01. The second-stage sun gear 401 rotates synchronously, serving as the power input driver for the second-stage planetary gear system. The rotation of the second-stage sun gear 401 drives the three second-stage planetary gears 402 meshing with it to rotate around their own axes. Similarly, the second-stage planetary gears 402 mesh with the second-stage internal tooth surface 202 of the integrated internal gear ring assembly 2, and the second-stage internal tooth surface 202 is fixed. The reaction force of the second-stage planetary gears 402 drives the second-stage planetary carrier 404 to revolve around the center of the second-stage sun gear 401, completing the second-stage reduction and further amplifying the torque. The internal spline 104 at the center of the second-stage planetary carrier 404 precisely meshes with the internal spline 104 at the output end 102 of the reducer housing 1. The revolution motion of the second-stage planetary carrier 404 transmits the amplified torque to the actuator of the shielded electric drive device through the spline engagement, realizing the final output of power. The first-stage and second-stage planetary gears 402 are both arranged asymmetrically at 118°, 120° and 122°, which disperses the meshing stress during transmission and further enhances the torque carrying capacity of the two-stage gear train to meet the requirements of a large transmission ratio.

[0036] In the two-stage planetary gear transmission process, minute errors in machining and assembly can easily lead to overload meshing of individual planetary gears. The load equalization compensation component 5 forms a dual load equalization mechanism through the passive radial floating of the elastic floating bushing 501 and the active self-aligning of the brass eccentric self-aligning bushing 503. This mechanism adjusts the meshing position in real time to ensure that the meshing load borne by each planetary gear is evenly distributed. The elastic floating bushing 501 is interference-fitted between the transition output shaft 305 and the second-stage sun gear 401, and clearance-fitted with the inner hole of the second-stage sun gear 401, allowing the second-stage sun gear 401 to float slightly radially. When there is a meshing deviation in the second-stage planetary gear system, the second-stage sun gear 401 automatically adjusts its position radially under the meshing reaction force of the planetary gears, making the meshing clearance between the three second-stage planetary gears 402 and the second-stage sun gear 401 and the second-stage internal tooth surface 202 uniform, thus passively equalizing the second-stage meshing load. Furthermore, between each first-stage and second-stage planetary gear 402 and the planetary shaft, a coaxial nested structure of copper-based solid self-lubricating bearing 502 and brass eccentric self-aligning bushing 503 is provided. The eccentricity of the brass eccentric self-aligning bushing 503 is 0.05~0.1mm. During assembly, the radial position of the planetary gear can be manually adjusted by rotating the eccentric bushing to actively compensate for machining errors. During transmission, if a planetary gear is overloaded, the self-aligning structure of the eccentric bushing can disperse the stress and prevent a single planetary gear from bearing an excessive load. The copper-based solid self-lubricating bearing 502 provides oil-free self-lubrication for the mating surfaces of the planetary shaft and the eccentric bushing. The micron-level micropores 505 of the outer ring of the double-row needle roller bearing 504 are impregnated with molybdenum disulfide lithium-based grease to achieve self-lubrication of the bearing, ensuring that the mating surfaces operate flexibly and without jamming during self-alignment and floating, and avoiding the impact of frictional resistance on the load-sharing effect.

[0037] The lubrication coordination component 6 is designed around the core principles of external oil storage, precise internal oil supply, and circulating oil return. It provides continuous and precise lubrication to the meshing surfaces and mating surfaces of the integrated internal gear ring assembly 2, the two-stage planetary gear system, and other components. Simultaneously, it avoids problems such as heat buildup in the confined space and excessive oil churning resistance, forming a closed-loop lubrication system. A micro-oil sump 601 is located on the inner bottom wall of the outer casing 1, below the outer side of the integrated internal gear ring assembly 2. High-viscosity extreme-pressure gear oil, added through a metering nozzle 605, is stored in the micro-oil sump 601, with the oil level controlled below the lowest meshing point of the planetary gears. During planetary gear transmission, the lower rim of the planetary gears extends into the micro-oil sump 601 through the oil outlet 602 at the bottom of the integrated internal gear ring assembly 2. As the planetary gears rotate, they pick up lubricating oil, which is then splashed towards the inner meshing area by centrifugal force, achieving splash lubrication. The integrated annular spacer 203 of the integrated internal gear ring assembly 2 has spirals machined on both sides. The guide oil groove 603 guides the lubricating oil splashed from the oil outlet 602 onto the inner wall of the internal gear ring. The lubricating oil is precisely guided along the spiral trajectory of the guide oil groove 603 to the meshing parts of the first and second stage internal gear surfaces 202 and the planetary gears, eliminating lubrication blind spots, ensuring the formation of an effective oil film on the meshing surfaces, and reducing tooth surface wear. Excess lubricating oil not absorbed by the meshing surfaces flows downward along the guide oil groove 603 and flows back to the micro oil pool 601 at the bottom of the outer shell 1 through the oil return outlet 604 at the bottom of the integrated annular spacer 203, realizing the recycling of lubricating oil and reducing oil loss. At the same time, it avoids the accumulation of lubricating oil in the meshing area and prevents excessive heat generated by oil stirring, which is suitable for the heat dissipation requirements of a small space. During the circulating lubrication process, a small amount of lubricating oil will seep into the mating surface of the double row needle roller bearing 504 and the eccentric bushing, complementing the grease in the bearing micropores 505, further improving the lubrication effect of the bearing and ensuring the long-term reliable operation of each moving pair.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A speed reducer for a shielded electric drive device, characterized in that, Includes a housing (1), an integrated internal gear ring assembly (2) is provided inside the housing (1), a first-stage compact planetary gear (3) and a second-stage compact planetary gear (4) are provided inside the integrated internal gear ring assembly (2), a load sharing compensation assembly (5) is provided inside the housing (1), and a lubrication coordination assembly (6) is provided inside the housing (1). The integrated internal gear ring assembly (2) is interference-fitted with the outer shell (1), and the integrated internal gear ring assembly (2) is used to eliminate the coaxiality deviation of the split internal gear ring; The load equalization compensation component (5) is used to equalize the load distribution of the first-stage compact planetary gear (3) and the second-stage compact planetary gear (4) under large transmission ratios; The lubrication coordination component (6) is used to ensure the long-term reliable operation of the integrated internal gear ring assembly (2).

2. The reducer for a shielded electric drive device according to claim 1, characterized in that, The housing (1) has an input terminal (101) on one side, which is located on the same side as the first-stage compact planetary gear (3). The input terminal (101) has a flat key (103) embedded inside to be compatible with the external motor. The housing (1) has an output terminal (102) on the other side, which is located on the same side as the second-stage compact planetary gear (4). The output terminal (102) is designed with an internal spline (104). The housing (1) adopts an integrated die-cast aluminum alloy design. The housing (1) is provided with reinforcing ribs (105).

3. The reducer for a shielded electric drive device according to claim 2, characterized in that, The inner wall of the integrated internal gear ring assembly (2) is provided with a primary internal gear surface (201) and a secondary internal gear surface (202). The primary internal gear surface (201) is meshed with a primary compact planetary gear (3), and the secondary internal gear surface (202) is meshed with a secondary compact planetary gear (4). An integrated annular spacer (203) is provided between the two internal gear surfaces of the integrated internal gear ring assembly (2).

4. The reducer for a shielded electric drive device according to claim 3, characterized in that, The first-stage compact planetary gear (3) includes a first-stage sun gear (301). The teeth of the first-stage sun gear (301) are integrally forged with the motor input end (101). The first-stage sun gear (301) is meshed with three first-stage planetary gears (302). Each first-stage planetary gear (302) meshes with the first-stage internal tooth surface (201). Each first-stage planetary gear (302) is sleeved on a first-stage planetary shaft (303). The first-stage planetary shafts (303) are all fixedly connected to the same first-stage planetary carrier (304). A transition output shaft (305) is provided at the center of the first-stage planetary carrier (304). The transition output shaft (305) is integrally forged with the first-stage planetary carrier (304).

5. The reducer for a shielded electric drive device according to claim 4, characterized in that, The secondary compact planetary gear (4) includes a secondary sun gear (401). The inner hole of the secondary sun gear (401) is connected to the transition output shaft (305). The secondary sun gear (401) is meshed with three secondary planetary gears (402). Each secondary planetary gear (402) meshes with the secondary internal tooth surface (202). Each secondary planetary gear (402) is sleeved on a secondary planetary shaft (403). The secondary planetary shafts (403) are all fixedly connected to the same secondary planetary carrier (404). The center position of the secondary planetary carrier (404) is adapted to the output end (102) of the outer casing (1). The internal spline (104) of the secondary planetary carrier (404) cooperates with the internal spline (104) of the output end (102) to achieve torque output.

6. The reducer for a shielded electric drive device according to claim 5, characterized in that, The three first-stage planetary gears (302) and the three second-stage planetary gears (402) are all arranged asymmetrically, and the included angles of the three planetary gears in each planetary gear set are set to 118°, 120° and 122° respectively.

7. The reducer for a shielded electric drive device according to claim 6, characterized in that, The load equalization compensation component (5) includes an elastic floating bushing (501) and a brass eccentric self-aligning bushing (503). The elastic floating bushing (501) is disposed between the secondary sun gear (401) and the transition output shaft (305). The elastic floating bushing (501) is interference-fitted with the transition output shaft (305), and the elastic floating bushing (501) is clearance-fitted with the inner hole of the secondary sun gear (401).

8. The reducer for a shielded electric drive device according to claim 7, characterized in that, The brass eccentric self-aligning bushing (503) is disposed between each planetary gear and the planetary shaft. The brass eccentric self-aligning bushing (503) is nested in the outer circle of the copper-based solid self-lubricating bearing (502). The inner hole of the copper-based solid self-lubricating bearing (502) is sleeved on the planetary shaft. A double-row needle roller bearing (504) is coaxially sleeved on the outer side of the brass eccentric self-aligning bushing (503). The inner ring of the double-row needle roller bearing (504) is clearance-fitted with the outer circle of the brass eccentric self-aligning bushing (503), and the outer ring is interference-fitted with the inner hole of the planetary gear. Micron-level micropores (505) are machined on the outer ring of the double-row needle roller bearing (504), and the micropores (505) are impregnated with molybdenum disulfide lithium-based grease.

9. The reducer for a shielded electric drive device according to claim 8, characterized in that, The lubrication coordination component (6) includes a micro oil sump (601), which is located on the bottom inner wall of the outer shell (1) in the area below the outer side of the integrated internal gear ring assembly (2). The bottom wall of the integrated internal gear ring assembly (2) is provided with an oil outlet notch (602) corresponding to the position of the first-level internal gear surface (201) and the second-level internal gear surface (202). The integrated annular spacer (203) is provided with oil guide grooves (603) on both sides. The integrated annular spacer (203) is provided with an oil return notch (604) at the bottom. The outer shell (1) is provided with a metering oil injection nozzle (605).

10. A method of using a reducer for a shielded electric drive device, applicable to the reducer for a shielded electric drive device as described in claim 9, characterized in that, The method includes the following steps: S1. Connect the output shaft of the external motor to the input end (101) of the reducer housing (1). A rigid torque connection between the motor and the first-stage sun gear (301) is achieved through the flat key (103) in the input end (101). The rotation of the motor drives the first-stage sun gear (301) to rotate synchronously. S2. The first-stage sun gear (301) drives the three first-stage planetary gears (302) to rotate. Because the first-stage planetary gears (302) mesh with the first-stage internal tooth surface (201) of the integrated internal gear ring assembly (2), the first-stage planetary carrier (304) is driven to revolve, completing the first-stage deceleration. The torque is transmitted to the second-stage sun gear (401) through the transition output shaft (305). S3, the second-stage sun gear (401) drives the three second-stage planetary gears (402) to rotate. The second-stage planetary gears (402) mesh with the second-stage internal tooth surface (202) of the integrated internal gear ring assembly (2), driving the second-stage planetary carrier (404) to revolve, completing the second-stage reduction, and the torque is amplified again and output through the internal spline (104); S4. The load sharing compensation component (5) forms a dual load sharing mechanism during the transmission process through the passive radial floating of the elastic floating bushing (501) and the active self-aligning of the brass eccentric self-aligning bushing (503), and adjusts the meshing position in real time to ensure that the meshing load borne by each planetary gear is evenly distributed. S5. The lubrication coordination component (6) stores oil through the micro oil tank (601). The planetary gear picks up lubricating oil from the oil outlet (602) and guides it to the meshing surface through the guide oil groove (603). The unadsorbed lubricating oil flows back to the micro oil tank (601) through the return oil outlet (604), forming a closed-loop lubrication system.

Images