Planetary reducer and motor

Abstract

The planetary reducer comprises a sun gear, planet gears, an inner gear ring and a planet carrier, the number of the planet gears is at least two, the planet gears are rotationally connected with the planet carrier, each planet gear is provided with a first gear and a second gear which are coaxially arranged and connected with each other, and the first gear and the second gear are coaxially arranged. The number of teeth of the first gear is larger than that of teeth of the second gear, the first gear is meshed with the sun gear, and the second gear is meshed with the inner gear ring. Wherein the number of teeth of the sun gear and the number of teeth of the inner gear ring are both positive integer multiples of the number of the planet gears, the ratio of the number of teeth of the first gear to the number of teeth of the second gear is a positive integer, and the phase angles of the first gear and the second gear are consistent. According to the invention, tooth alignment is not needed during assembling and manufacturing, the assembling difficulty and the manufacturing cost are reduced, the excellent rate is improved, and meanwhile, the motor is effectively prevented from being stuck.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of speed reducer, and particularly relates to a planetary speed reducer and a motor. BACKGROUND

[0002] In the technical field of planetary speed reducer, in order to realize high reduction ratio of 15-20 under single-stage transmission, the meshing precision between the planetary gear and the sun gear and the inner gear ring needs to be strictly ensured in the assembly process of the existing NW type planetary structure, and the tooth profile modification and tooth processing requirements are extremely strict. If the tooth deviation or tooth surface contact is poor during assembly, it will directly lead to transmission jamming, motor locked-rotor, and even over-current burning, and the traditional assembly process is difficult to stably meet such precision requirements. CONTENT OF THE UTILITY MODEL

[0003] The purpose of the embodiment of the present application is to provide a planetary speed reducer and a motor, which realizes no tooth processing during assembly and manufacturing, reduces assembly difficulty and manufacturing cost, improves yield, and effectively avoids motor jamming.

[0004] In order to achieve the above purpose, the following technical scheme is adopted in the present application:

[0005] On the one hand, a planetary speed reducer is provided, which comprises a sun gear, a planetary gear, an inner gear ring and a planet carrier, the number of the planetary gears is at least two, the planetary gears are rotationally connected with the planet carrier, the planetary gears have coaxially arranged and connected first gears and second gears, the number of teeth of the first gears is greater than that of the second gears, the first gears are meshed with the sun gear, and the second gears are meshed with the inner gear ring; wherein the number of teeth of the sun gear and the number of teeth of the inner gear ring are positive integer multiples of the number of the planetary gears, the ratio of the number of teeth of the first gears to the number of teeth of the second gears is a positive integer, and the phase angles of the first gears and the second gears are consistent. The number of teeth of the sun gear and the number of teeth of the inner gear ring are integer multiples of the number of the planetary gears, the ratio of the number of teeth of the first gears of the planetary gears to the number of teeth of the second gears is an integer and the phase angles are consistent, and such mathematical relationship ensures that all gears can naturally form correct meshing phase during assembly, avoiding the complex tooth processing of the traditional planetary speed reducer. The consistency of the phase angles reduces the meshing impact, and the optimized torque transmission path further improves the transmission efficiency.

[0006] Further, the number of the planetary gears is three, and the number of teeth of the sun gear and the number of teeth of the inner gear ring are positive integer multiples of three. By setting three planetary gears, the load is dispersed, the load-carrying capacity of the speed reducer is improved, and the uniformity and stability of power transmission are enhanced.

[0007] Further, the planetary reducer further comprises a gear box, the sun gear, the planet gears, the inner ring gear and the planet carrier are at least partially arranged in the gear box, the inner ring gear is fixedly connected with the gear box, and the planet carrier is rotatably connected with the gear box. By fixing the inner ring gear in the gear box, the planet carrier serves as a driving end, which simplifies the structure and improves the stability and efficiency of power transmission, avoids the complexity and additional loss caused by the linkage between the inner ring gear and the planet carrier in the traditional structure, and ensures the stability and precision of power output.

[0008] Further, bearings are arranged at both ends of the planet carrier, and the planet carrier is rotatably installed in the gear box through the bearings. By arranging bearings at both ends of the planet carrier and rotatably installing the planet carrier in the gear box through the bearings, the rotation precision and stability of the planet carrier are significantly improved.

[0009] Further, the first gear and the second gear are integrally formed. The planet gear made by integral forming has high structural strength, and can ensure that the related parameters of the first gear and the second gear remain consistent.

[0010] Further, the sun gear has Z1 teeth, the inner ring gear has Z2 teeth, the first gear has Z3 teeth, and the second gear has Z4 teeth, wherein the reduction ratio i = Z2 / Z1*(Z3 / Z4) + 1, and Z1 < Z3 < Z2, Z3 > Z4. This tooth number relationship ensures that the planet gears can naturally form the correct meshing phase during assembly, without the need for complex tooth alignment operations, significantly reducing the assembly difficulty.

[0011] Further, 12 ≤ Z1 ≤ 30, 45 ≤ Z2 ≤ 120, 24 ≤ Z3 ≤ 90, and 12 ≤ Z4 ≤ 30. This ensures that the dimensions and performance of each gear are optimally matched when the planetary reducer achieves a high reduction ratio of 10 to 20. This tooth number range not only optimizes the transmission efficiency and torque output of the reducer, but also ensures the compactness of the structure and the stability of power transmission.

[0012] Further, a transmission shaft is connected to the side of the sun gear away from the planet carrier. The transmission shaft and the sun gear can be integrally formed, ensuring stable and consistent torque transmission and ensuring that the structural strength between the two can meet the assembly and use requirements.

[0013] Further, a planet shaft is arranged on the planet carrier, and the planet shaft is rotatably connected with the planet gear.

[0014] On the other hand, an electric motor comprising the planetary reducer as described above is also provided.

[0015] The beneficial effects of the present application are: in the high reduction ratio planetary reducer scheme, in order to ensure the stability of transmission, the planetary gear is provided with at least two, and then the number of teeth of the sun gear and the inner gear ring is set to be an integer multiple of the number of planetary gears, and the tooth number ratio of the first gear and the second gear is kept in an integer relationship and the phase angle is consistent, so that the complex gear alignment operation in the assembly process is not needed, the assembly difficulty and the manufacturing cost are significantly reduced; in addition, compared with other types of reducers, the present application realizes high reduction ratio output on the structure of single-stage reduction, and therefore the structure is more compact and the weight is smaller. BRIEF DESCRIPTION OF DRAWINGS

[0016] The present application will be further described in detail below according to the drawings and embodiments.

[0017] Figure 1 It is a perspective view of the planetary reducer described in the embodiment of the present application.

[0018] Figure 2 It is an exploded view of the planetary reducer described in the embodiment of the present application.

[0019] Figure 3 It is a side view of the planetary reducer described in the embodiment of the present application.

[0020] Figure 4 It is a cross-sectional view of A-A in the embodiment of the present application. Figure 3

[0021] Figure 5 It is a perspective view of the planetary gear described in the embodiment of the present application.

[0022] In the figure: 1, sun gear; 2, planetary gear; 201, first gear; 202, second gear; 203, assembly hole; 3, inner gear ring; 4, planet carrier; 5, planetary gear; 6, gear box; 7, bearing; 8, transmission shaft. DETAILED DESCRIPTION

[0023] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present application are further described in detail below. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] ​In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0025] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower than the second feature in horizontal height.

[0026] In the prior art field of motor reducers, the mainstream structure mainly includes worm gear structure and parallel gear structure. The worm gear structure realizes power transmission through staggered shaft transmission, and the characteristics of the worm screw helical teeth pushing the worm gear to rotate give the system self-locking function, but the structure is generally maintained at 60%-70% due to the sliding friction mechanism. Although the existing technology tries to improve the performance by optimizing the gear parameters, implementing surface hardening treatment and precise assembly, etc., the efficiency bottleneck is still difficult to break through, and the manufacturing cost is high.

[0027] The parallel gear structure is designed with different shafts of the input shaft and the output shaft, which leads to the overall structure size of the reducer being large, the shape being irregular and the weight being significantly increased, which is difficult to meet the strict demand for compactness and lightness. In addition, although the traditional planetary reduction structure (such as NGW type) has certain advantages in efficiency and coaxiality, its single-stage reduction ratio is usually limited to within 10. When a high reduction ratio of 15-20 is required, a multi-stage series structure must be used, which not only leads to a sharp rise in system complexity and cost, but also adversely affects the size control.

[0028] In the 15-20 deceleration ratio interval, the NW type planetary structure can theoretically meet the comprehensive needs of small size, high efficiency and lightweight due to its coaxial layout characteristics. However, the strict requirements of design precision, manufacturing process and assembly technology of this structure have become a major obstacle to its popularization and application. Specifically, the traditional NW planetary reducer needs to ensure the uniform distribution of planetary gears through precise tooth matching process, which puts forward very high requirements for gear machining precision and assembly process, resulting in low yield and high production cost, and thus the NW planetary reducer is extremely rare in the existing electric wheelchair motor market.

[0029] The traditional NW planetary reducer is usually composed of a sun gear, multiple planetary gears, an inner ring gear and a planet carrier. Its working principle is that the sun gear inputs power to drive the planetary gears to revolve around the sun gear and rotate themselves, and the planet carrier realizes deceleration output. This structure performs well in terms of carrying capacity, transmission ratio range and efficiency, but has the following shortcomings in actual application:

[0030] 1. High assembly complexity: Since the planetary gears need to be uniformly distributed and mesh with the sun gear and the inner ring gear at the same time, the phase angle of each gear needs to be accurately adjusted during assembly to ensure the meshing accuracy. If the gears are not correctly assembled, it will cause the motor to be stuck, the current to be large, and the use of the motor to be affected.

[0031] 2. Cost constraints: High-precision machining requirements and complex assembly process increase production costs.

[0032] 3. Structural limitations: Single-stage deceleration ratio is limited, and multiple-stage series structure is needed to achieve large transmission ratio, further increasing the system size, weight and cost.

[0033] 4. Efficiency bottleneck: Friction loss caused by multi-stage transmission reduces overall transmission efficiency.

[0034] To solve the above problems, such as Figures 1-5As shown, the present embodiment proposes a new NW type planetary reducer, aiming to solve the problem of high gear matching difficulty leading to motor stall in traditional NW planetary reducer through innovative design, while meeting the demand of high reduction ratio, compactness and lightweight of single-stage reducer. The core structure of the new NW type planetary reducer includes a sun gear 1, a planet gear 2, an inner ring gear 3 and a planet carrier 4. The planet gear 2 is rotationally connected with the planet carrier 4, and the planet gear 2 has a first gear 201 and a second gear 202 arranged coaxially and connected with each other, the number of teeth of the first gear 201 is greater than that of the second gear 202, the first gear 201 is engaged with the sun gear 1, and the second gear 202 is engaged with the inner ring gear 3. The number of planet gears 2 is at least two (for example, it can be two, three or more). The number of teeth of the sun gear 1 and the number of teeth of the inner ring gear 3 are both positive integer multiples of the number of planet gears 2, ensuring that all gears can naturally form the correct meshing phase during assembly. The ratio of the number of teeth of the first gear 201 to the number of teeth of the second gear 202 is a positive integer, and the phase angles of the first gear 201 and the second gear 202 are consistent, thereby realizing smooth power transmission. In this scheme, the sun gear 1 serves as a power input component, which is engaged with the first gear 201 of the planet gear 2 to drive the planet gear 2 to rotate, the second gear 202 of the planet gear 2 is engaged with the inner ring gear 3, and the rotational connection between the planet gear 2 and the planet carrier 4 transmits the power of the planet gear 2 to the planet carrier 4 for output.

[0035] In the traditional NW planetary reducer, the key technical problem in the assembly process is how the planet gear 2 simultaneously achieves correct engagement with the sun gear 1 and the inner ring gear 3. Since the position of each gear is not fixed during assembly, if the phases are not correctly engaged, the sun gear 1 cannot be assembled into the planet gear train. The traditional way is to force it in, which easily leads to motor stall, rapid current increase and motor failure.

[0036] Based on the above scheme, the new NW type planetary reducer solves the above problems through the following innovative design:

[0037] Simplify the assembly process: by designing the tooth number relationship of the sun gear 1 and the inner ring gear 3, and the positive integer tooth number ratio of the planet gear 2, all gears can naturally form the correct meshing phase during assembly, without the need for complex gear matching operation of traditional NW structure, significantly improving the assembly efficiency.

[0038] Optimize the transmission chain: upgrade the traditional single gear to the integrated planet gear 2 with first gear 201 and second gear 202, realize two-stage transmission through a single component, simplify the transmission chain, and eliminate the efficiency loss caused by multi-stage structure.

[0039] Improve transmission efficiency: the consistent phase angle design reduces the meshing impact, and combined with the optimized torque transmission path, it significantly improves the transmission efficiency while maintaining the self-locking ability.

[0040] In summary, the new NW planetary reducer proposed in this embodiment solves the technical problems in the assembly process of traditional NW planetary reducers through innovative design of the planetary gear 2 and the gear tooth number relationship, while achieving significant optimization in compactness, transmission efficiency, and manufacturing cost. This design not only improves the performance of the product, but also provides a new technical direction for the manufacturing and application of planetary reducers. By simplifying the assembly process and optimizing the transmission chain, this scheme can significantly reduce manufacturing costs in practical applications, while maintaining efficient power transmission and stable operating performance, bringing breakthrough progress to the field of electric wheelchair motor reducers.

[0041] In one embodiment, the number of planetary gears 2 is three, and the specific number can also be flexibly selected according to actual design requirements (such as four, five, or six, etc.). By adjusting the number of planetary gears 2, the dynamic optimization of transmission performance and structural parameters is achieved to meet different usage requirements. When the number of planetary gears 2 increases, multiple planetary gears 2 are evenly distributed on the inner side of the inner ring gear 3 through the planet carrier 4, forming a multi-path parallel transmission mode. The first gear 201 of each planetary gear 2 is meshed with the sun gear 1, and the second gear 202 is meshed with the inner ring gear 3, and the reduction output is achieved through the rotational connection of the planetary gear 2 and the planet carrier 4, achieving the purpose of multi-tooth sharing and collaborative transmission of power.

[0042] The number of teeth of the sun gear 1 and the inner ring gear 3 is always a positive integer multiple of the number of planetary gears 2. This mathematical relationship ensures that the meshing phase of each gear can be naturally aligned regardless of the number of planetary gears 2. For example: if three planetary gears 2 are used, the number of teeth of the sun gear 1 is a positive integer multiple of 3 (such as 18 teeth), and the number of teeth of the inner ring gear 3 is a positive integer multiple of 3 (such as 90 teeth), then the first gear 201 (such as 45 teeth) of each planetary gear 2 and the sun gear 1, and the second gear 202 (such as 15 teeth) and the inner ring gear 3 can achieve phaseless meshing.

[0043] In one embodiment, the outer diameter of the first gear 201 is greater than the outer diameter of the second gear 202.

[0044] In practical applications, increasing the number of planetary gears 2 (such as six-tooth layout) can increase the number of meshing teeth, achieving higher torque carrying capacity under the same module, suitable for heavy-duty electric wheelchairs or climbing working conditions. Reducing the number of planetary gears 2 (such as double-tooth layout) can reduce the rotational inertia of the planet carrier 4, reducing the delay of dynamic response, suitable for auxiliary driving systems with high response speed requirements.

[0045] In some embodiments, the planetary reducer further comprises a gear box 6, the sun gear 1, the planet gears 2, the inner ring gear 3 and the planet carrier 4 are all arranged at least partially in the gear box 6, the inner ring gear 3 is fixedly connected with the gear box 6, and the planet carrier 4 is rotatably connected with the gear box 6. Specifically, both ends of the planet carrier 4 are provided with bearings 7, and the planet carrier 4 is rotatably installed in the gear box 6 through the bearings 7. The planet carrier 4 at both ends is rigidly constrained with the gear box 6 through the bearings 7, forming a simply supported beam mechanical model. When the planet carrier 4 rotates around the central axis, the double-end bearings 7 synchronously bear the radial load and the axial load, and transmit the load to the gear box 6 shell through the rolling elements, thereby achieving stable support. The double-bearing 7 layout makes the planet carrier 4 form a symmetrical stress state during rotation. When the planet gears produce radial vibration due to meshing impact, the two-end bearings 7 absorb vibration energy through elastic deformation, and restore balance through pre-tightening force adjustment, avoiding the deflection or jamming of single-sided bearings 7 caused by overload.

[0046] wherein the reduction ratio i of the planetary reducer is between 10 and 20, the number of teeth of the sun gear 1 is Z1, the number of teeth of the inner ring gear 3 is Z2, the number of teeth of the first gear 201 is Z3, and the number of teeth of the second gear 202 is Z4, wherein the reduction ratio i = Z2 / Z1*(Z3 / Z4)+1, and Z1<Z3<Z2, Z3>Z4. The planet gears 2 are designed to achieve a compound transmission ratio through two-stage meshing. The first-stage transmission is meshed by the sun gear 1 (Z1) and the first gear 201 (Z3) of the planet gears 2, and the transmission ratio is Z3 / Z1; the second-stage transmission is meshed by the second gear 202 (Z4) of the planet gears 2 and the inner ring gear 3 (Z2), and the transmission ratio is Z2 / Z4. After the two-stage transmission ratios are superimposed, the total reduction ratio is i = Z2 / Z1*(Z3 / Z4)+1, wherein the "+1" term is derived from the differential characteristics of the planetary transmission.

[0047] Z1<Z3<Z2: ensures that the first-stage transmission is a speed-up ratio (Z3 / Z1>1), and the second-stage transmission is a large deceleration ratio (Z2 / Z4□1), thereby achieving a high total reduction ratio through the product of the two-stage transmission ratios. Z3>Z4: ensures that the inside of the planet gears 2 is a deceleration transmission (Z3 / Z4>1), avoids power backflow, and improves transmission efficiency.

[0048] By adjusting the specific tooth combinations of Z1, Z2, Z3 and Z4, the reduction ratio can be flexibly set within the range of 10 to 20. Specifically, 12≤Z1≤30, 45≤Z2≤120, 24≤Z3≤90, and 12≤Z4≤30.

[0049] For example, in the case of two planetary gears 2, if the reduction ratio i = 11 is required, Z1 = 12, Z2 = 60, Z3 = 24, and Z4 = 12 can be selected, and i = 60 / 12*(24 / 12) + 1 = 11. The tooth number relationship Z1 < Z3 < Z2 and Z3 > Z4 is automatically satisfied without additional complex calculations.

[0050] Alternatively, Z1 = 30, Z2 = 120, Z3 = 90, and Z4 = 30 can be selected, and the reduction ratio i = 120 / 30*(90 / 30) + 1 = 13.

[0051] In an alternative embodiment, when the number of planetary gears 2 is three, Z1 = 15, Z2 = 81, Z3 = 57, and Z4 = 19, the reduction ratio i = 81 / 15*(57 / 19) + 1 = 17.2. Alternatively, Z1 = 12, Z2 = 45, Z3 = 36, and Z4 = 18, and the reduction ratio i = 45 / 12*(36 / 12) + 1 = 12.25.

[0052] It is worth mentioning that there is a key technical problem in the traditional assembly process of NW planetary reducer: the planetary gear 2 is composed of two gears combined together, and there are various phase combinations when the two gears are combined. Without special pressing tooling, the planetary gear 2 made at the end will have different phases. Because of this consistency difference, when the planetary gear train is finally assembled, it will not fit or be stuck. Although high-precision tooling can be used to ensure the consistency of the planetary gear 2, the accuracy and cost are risks.

[0053] To solve this problem, the planetary gear 2 in this embodiment is molded by mold injection molding, powder metallurgy molding or injection molding to ensure the consistency of the planetary gear 2 and the phase angle consistency of the first gear 201 and the second gear 202.

[0054] Mold injection molding: molten material is injected into a precise mold cavity, and through optimized runner and gate design, the material is uniformly filled in the complex tooth shape area. The mold temperature control system cooperates with the circulating cooling to realize rapid and uniform solidification, and to ensure the tooth shape precision.

[0055] Powder metallurgy molding: metal powder is pressed into shape under high pressure, and the material density and mechanical properties are enhanced through high-temperature sintering. This process is suitable for complex planetary gears 2, has high material utilization rate, and can maintain accurate tooth size.

[0056] Injection molding: supports a variety of low-viscosity materials (such as thermoplastic plastics, rubber, etc.), and realizes one-time molding of complex structures through screw plasticization and high-efficiency injection. The pressure compensation technology eliminates material shrinkage to ensure the quality of the tooth surface.

[0057] In the premise of ensuring consistency, the manufacturing of the planetary gear 2 can be selected according to actual design requirements, such as mold injection, powder metallurgy or injection molding process, combined with phase angle control design, to realize efficient, accurate and low-cost manufacturing.

[0058] In one embodiment, the first gear 201 and the second gear 202 are integrally formed. From the perspective of structural stability, integrally forming eliminates the problem of poor meshing caused by assembly errors or loose connectors in traditional combined gears, so that the two gears (the first gear 201 and the second gear 202) always maintain accurate relative positions during operation, greatly reducing vibration, noise and energy loss caused by misalignment, thereby significantly improving the smoothness and reliability of the reducer. In terms of manufacturing process, integrally forming simplifies the assembly process, eliminating the complex tooth alignment and press fitting processes of traditional combined gears, which not only improves production efficiency, but also avoids quality problems caused by improper assembly and reduces manufacturing costs. At the same time, the integrally forming process can more accurately control the consistency of the phase angles of the two gears, ensuring better synchronization when they rotate, further optimizing the smoothness and efficiency of power transmission. In addition, the integrally formed design also helps to achieve lightweight of the reducer, reducing unnecessary materials and structures, making the overall weight lighter and the structure more compact, and being more suitable for applications with strict requirements on weight and size.

[0059] In one embodiment, the sun gear 1 is connected to the transmission shaft 8 on the side away from the planet carrier 4, and the transmission shaft 8 and the sun gear 1 can be integrally formed. This structure ensures the absolute coaxiality of the sun gear 1 and the transmission shaft 8 through a single molding process, eliminating vibration and noise problems caused by traditional assembly errors, while shortening the power transmission path to improve transmission efficiency; the integrated rigid connection avoids the interface energy loss of the split structure, and the gradient heat treatment process realizes the balance between tooth wear resistance and shaft neck fatigue resistance, prolonging the service life while reducing maintenance costs

[0060] In addition, the planet carrier 4 is provided with a planet shaft 5, and the planet shaft 5 is rotationally connected with the planetary gear 2. Specifically, the planet shaft 5 is integrally formed on the planet carrier 4, and the planetary gear 2 is provided with an assembly hole 203 rotationally connected with the planet shaft 5. The planet carrier 4 and the planet shaft 5 are made by integrally forming, ensuring that the planet shaft 5 and the planet carrier 4 form a rigid whole, eliminating the coaxiality deviation caused by gaps or deformation in traditional assembly process from the root, so that the planetary gear 2 maintains a high degree of stable dynamic balance when rotating at high speed.

[0061] As another alternative embodiment, in the planetary reducer, the planet carrier 4 is fixed inside the gear box 6, and the inner ring 3 serves as the driving end. In this scheme, the planet carrier 4 is directly fixed to the inner wall of the gear box 6 through splines or bolts, ensuring complete staticity. Its integrated casting or forging process combined with internal reinforcement rib design significantly improves torsional stiffness, providing stable support for the planet wheels 2. The outer edge of the inner ring 3 is machined with splines or pin holes, connected with the output end cover of the gear box 6 through spline pairs or pins, forming a direct torque transmission path. At the same time, the contact surface between the output end cover and the inner ring 3 adopts a labyrinth seal or O-ring seal, effectively preventing lubricating oil leakage.

[0062] On the other hand, an electric motor is also provided, which can be applied to scenarios such as electric wheelchairs, including the planetary reducer as described above. The new NW-type planetary reducer significantly improves transmission efficiency and reduces energy loss through the optimized transmission chain of the planet wheels 2, which enables electric wheelchairs to achieve longer cruising range under the same battery capacity, meeting the user's needs in daily commuting, long-distance travel, or complex terrain. This advantage is particularly prominent in environments that require long-term movement, such as hospitals, shopping malls, and airports.

[0063] The reducer adopts a coaxial layout and planet wheel 2 design, significantly reducing the radial size and overall weight. This compact and lightweight design makes the electric wheelchair more portable, making it easier for users to store, transport, or load into the trunk of a car. For users who need to move frequently (such as the elderly or the disabled), this design greatly improves the convenience of use.

[0064] In addition, through the optimized torque transmission path and phase angle consistency design, the new NW-type planetary reducer can provide greater torque output while maintaining high efficiency. This enables electric wheelchairs to easily handle slopes, rough terrain, or muddy terrain, ensuring user mobility in various complex environments. For example, in scenarios such as parks, mountainous areas, or unpaved roads, this high-torque output capability can significantly improve the wheelchair's passability and stability.

[0065] At the same time, the phase angle consistency design of the planet wheels 2 reduces meshing impact, significantly reducing noise and vibration during operation. This is crucial for electric wheelchair users, as a quiet and smooth operating environment can significantly improve the comfort of riding, especially during long-term use, effectively reducing fatigue.

[0066] The planetary gear 2 manufactured by a mold injection molding, powder metallurgy molding or injection molding process not only ensures consistent phase angle, but also significantly improves the durability and wear resistance of the gear. Combined with an optimized sealing design, this reducer can effectively prevent lubricating oil leakage and prolong the service life. This high reliability and low maintenance cost design makes the electric wheelchair more economical and practical in long-term use, reducing the maintenance burden of users.

[0067] It is worth noting that in addition to electric wheelchairs, the motor can also be applied in industrial robot joints, collaborative robot end tools, semiconductor manufacturing equipment, electric bicycle center motors, intelligent logistics sorting robots, etc. Among them, high assembly precision ensures the positioning accuracy of the end effector to be micron level, compact structure adapts to the narrow installation space of the robot arm, high reduction ratio realizes low speed and large torque output, and meets the precise operation requirements of welding, assembly, etc. Compact structure facilitates integration into dexterous hands, quick-change clamps and other end effectors, high assembly precision ensures micro parts operation in 3C electronic assembly, high reduction ratio provides sufficient gripping torque and avoids inertial impact. High-precision transmission meets the nanometer-level positioning requirements of lithography machine worktables and wafer transfer robots, compact design adapts to the space constraints of clean rooms, and high reduction ratio realizes smooth and low-speed movement in vacuum environment. High reduction ratio provides large torque output required for climbing, compact structure is embedded in the lower tube of the frame, high assembly precision reduces operating noise and improves riding comfort, while modular design adapts to different vehicle models. Compact structure adapts to the narrow space of AGV car chassis, high reduction ratio drives heavy load transportation, high assembly precision ensures path tracking accuracy during multi-vehicle collaborative operation, and improves warehouse efficiency.

[0068] In the description herein, it should be understood that the terms "upper", "lower", "left", "right", and the like orientation or position relationship are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0069] In the description of the present specification, the description referring to the terms "an embodiment", "an example" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0070] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

[0071] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for the purpose of explaining the principles of the present application, and cannot be interpreted in any way as a limitation on the scope of protection of the present application. Based on the explanations here, those skilled in the art can think of other specific embodiments of the present application without creative labor, and these ways will fall within the scope of protection of the present application.

Claims

1. A planetary reducer, characterized in that, include: The assembly comprises a sun gear (1), planet gears (2), an internal gear ring (3), and a planet carrier (4). The number of planet gears (2) is at least two. The planet gears (2) are rotatably connected to the planet carrier (4). Each planet gear (2) has a first gear (201) and a second gear (202) that are coaxially arranged and connected to each other. The number of teeth of the first gear (201) is greater than the number of teeth of the second gear (202). The first gear (201) meshes with the sun gear (1), and the second gear (202) meshes with the internal gear ring (3). The number of teeth of the sun gear (1) and the number of teeth of the internal gear ring (3) are both positive integer multiples of the number of planet gears (2). The ratio of the number of teeth of the first gear (201) to the number of teeth of the second gear (202) is a positive integer, and the phase angles of the first gear (201) and the second gear (202) are the same.

2. The planetary reducer according to claim 1, characterized in that, The number of planetary gears (2) is three, and the number of teeth of the sun gear (1) and the number of teeth of the internal gear ring (3) are both positive integer multiples of three.

3. The planetary reducer according to claim 1, characterized in that, The planetary reducer also includes a gearbox (6), and the sun gear (1), the planet gears (2), the internal gear ring (3) and the planet carrier (4) are at least partially disposed in the gearbox (6). The internal gear ring (3) is fixedly connected to the gearbox (6), and the planet carrier (4) is rotatably connected to the gearbox (6).

4. The planetary reducer according to claim 3, characterized in that, It also includes bearings (7) disposed at both ends of the planetary carrier (4), and the planetary carrier (4) is rotatably mounted in the gearbox (6) through the bearings (7).

5. The planetary reducer according to any one of claims 1-4, characterized in that, The first gear (201) and the second gear (202) are integrally formed parts.

6. The planetary reducer according to any one of claims 1-4, characterized in that, The number of teeth of the sun gear (1) is Z1, the number of teeth of the internal gear ring (3) is Z2, the number of teeth of the first gear (201) is Z3, and the number of teeth of the second gear (202) is Z4. The reduction ratio i = Z2 / Z1*(Z3 / Z4)+1, and Z1 < Z3 < Z2, Z3 > Z4.

7. The planetary reducer according to claim 6, characterized in that, 12≤Z1≤30, 45≤Z2≤120, 24≤Z3≤90, 12≤Z4≤30.

8. The planetary reducer according to any one of claims 1-4, characterized in that, The sun gear (1) is connected to a drive shaft (8) on the side away from the planet carrier (4).

9. The planetary reducer according to any one of claims 1-4, characterized in that, The planet carrier (4) is provided with a planetary shaft (5), which is rotatably connected to the planetary gear (2).

10. An electric motor, characterized in that, Including the planetary reducer as described in any one of claims 1-9.

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