A deceleration motor

Abstract

The application discloses a speed reduction motor, which comprises a stator assembly, a rotor assembly, an inner tooth assembly and a speed reduction assembly. The rotor assembly is arranged on the inner side of the stator assembly. An inner ring of the rotor assembly is formed with a containing space. The inner tooth assembly is at least partially located in the containing space. The speed reduction assembly is at least partially located in the containing space and is engaged with the inner tooth assembly. A power output end of the rotor assembly is connected with a power input end of the speed reduction assembly. The inner tooth assembly and the speed reduction assembly are at least partially embedded in the containing space, so that the structural size of the whole motor is greatly reduced, and the mass of the whole motor is reduced.

Description

Technical Field

[0001] This application relates to the technical field of electric motors, and more particularly to a geared motor. Background Technology

[0002] As a core component for robot joint actuation, planetary reducers are increasingly important in the robotics industry due to their performance and lightweight design requirements. With the diversification of robot applications, planetary reducers need to achieve further lightweight design while maintaining high torque density and load capacity to meet the demands of flexible deployment and energy efficiency optimization. However, in existing technologies, there is still room for optimization in the weight distribution and structural design of planetary reducers, especially in multi-stage reducers where the weight of key components accounts for a high proportion, affecting the overall machine quality. Utility Model Content

[0003] The purpose of this application is to provide a geared motor that greatly reduces the overall structural size of the motor by embedding both the internal gear assembly and the reduction assembly at least partially into the accommodating space, thereby reducing the overall weight of the motor.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] On one hand, a geared motor is provided, comprising: a stator assembly, a rotor assembly, an internal gear assembly, and a reduction assembly. The rotor assembly is disposed inside the stator assembly, and an inner ring of the rotor assembly forms an accommodating space. The internal gear assembly is at least partially located within the accommodating space. The reduction assembly includes a primary reducer and a secondary reducer coaxially arranged. The power output end of the rotor assembly is drive-connected to the power input end of the primary reducer, and the power input end of the secondary reducer is drive-connected to the power output end of the primary reducer. The primary reducer is disposed within the accommodating space and meshes with the internal gear assembly. The secondary reducer is at least partially located within the accommodating space and meshes with the internal gear assembly. This geared motor achieves a high degree of structural integration by embedding the internal gear assembly and the reduction assembly into the accommodating space of the inner ring of the rotor assembly: breaking through the limitations of traditional external layouts, the axial dimension is shortened by more than 30%, and the power density is increased by more than 15%. The embedded design optimizes the force transmission path and reduces energy loss. The lightweight gear ring and dynamically preloaded bearing work together to suppress vibration, making it suitable for high-precision scenarios such as robot joints. At the same time, it reduces assembly processes and significantly improves production economy.

[0006] Furthermore, the rotor assembly includes a magnet and a support. The magnet is disposed inside the stator assembly and has a mounting cavity. A portion of the mounting cavity is fitted onto the outer peripheral wall of the support, and the remaining portion of the mounting cavity forms the accommodating space. The support is connected to the power input end of the first-stage reducer. By partially placing the support within the mounting cavity of the magnet to provide support, while simultaneously allowing the remaining space within the mounting cavity to form an accommodating space, the space of the internal gear assembly, the reduction assembly, and the magnet can be reused.

[0007] Furthermore, it also includes a housing. The internal gear assembly includes an internal gear ring and a fixing frame. The fixing frame is located within the accommodating space. The internal gear ring is sleeved on the outer periphery of the first-stage reducer and meshes with it. The internal gear ring is sleeved on at least a portion of the outer periphery of the second-stage reducer and meshes with it. One end of the internal gear ring is fixedly connected to the housing, and the other end is connected to the fixing frame. The double-end constraint design of the internal gear ring forms a closed-loop force transmission path through the synergistic effect of the rigid connection of the housing and the elastic support of the fixing frame.

[0008] Furthermore, the internal gear ring has a greater structural strength than the fixed frame, and the internal gear ring and the fixed frame are detachably connected. The internal gear ring uses a high-strength material to concentrate the meshing stress, while the fixed frame uses a lightweight structure for auxiliary support. By matching materials in different zones, the overall weight is reduced while ensuring transmission stability, and the components can be disassembled for easy maintenance and replacement.

[0009] Furthermore, a bearing is provided between the power output end of the reduction assembly and the internal gear ring. The outer ring of the bearing is clearance-fitted with the internal gear ring, and the inner ring of the bearing is interference-fitted with the power output end of the secondary reducer. This bearing fit scheme releases thermal deformation stress through the outer ring clearance and locks the power transmission path through the inner ring interference, forming a dynamically stable transmission system.

[0010] Furthermore, the internal gear ring includes a main ring body and a plurality of spaced-apart limiting portions protruding from the outer edge of the main ring body on the side opposite to the bearing. The inner side of the limiting portion is clearance-fitted with the outer ring of the bearing, and the main ring body is fixedly connected to the housing through the limiting portions. The spaced-apart limiting portions eliminate redundant material in the main ring body by discretizing the connection points, thereby achieving a lightweight internal gear ring.

[0011] Furthermore, one end face of the bearing abuts against the inner wall of the housing, and the other end face of the bearing faces the end face of the main ring body. A washer is provided between the bearing and the main ring body. The washer cooperates with the limiting part to complete the pre-tightening installation of the bearing from the axial and radial directions.

[0012] Furthermore, the outer edge of the main ring body opposite to the bearing has multiple protruding mounting parts at intervals, and the fixing bracket is located inside the mounting parts and locked by fasteners. The spaced layout eliminates redundant material, while the multi-point locking improves the uniformity of circumferential stiffness distribution.

[0013] Furthermore, the inner side of the main ring body is provided with a first rack and a second rack that are interconnected. The first rack and the second rack are arranged at intervals. The first rack meshes with the first-stage reducer, and the second rack meshes with the second-stage reducer. By setting two reducers meshing with double racks on the main ring body, and allowing the two reducers to share a single inner gear ring, the overall weight of the motor can be effectively reduced. At the same time, the double racks can be used for zoned load bearing, ensuring that the load at each stage is precisely matched to the material strength threshold, thus reducing the risk of vibration coupling.

[0014] Furthermore, the inner non-meshing areas of the main ring are all flat curved surfaces. The flat curved surfaces of the non-meshing areas of the main ring achieve weight reduction by removing redundant material, while the continuous and smooth geometric configuration optimizes the stress transmission path and improves bending stiffness.

[0015] The beneficial effects of this application are as follows: By embedding at least partially the internal gear assembly and the reduction assembly into the accommodating space formed by the inner ring of the rotor assembly, a significant compactness of the overall motor structure is achieved. This more compact structure allows for a reduction in the size of corresponding internal and external structures, thereby reducing the weight of these structures and effectively reducing the overall mass of the motor. This improves the overall power density, energy efficiency, and operational stability. This solution not only optimizes the motor's performance but also enhances its adaptability, enabling it to better meet the needs of diverse application scenarios while reducing production costs. Attached Figure Description

[0016] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a perspective view of the geared motor described in the embodiments of this application;

[0018] Figure 2 This is a side view of the geared motor described in the embodiment of this application;

[0019] Figure 3 Examples of this application Figure 2 Schematic diagram of the cross section at point AA;

[0020] Figure 4 This is an assembly drawing of the stator assembly and rotor assembly described in the embodiments of this application;

[0021] Figure 5 This is an exploded view of the stator assembly and rotor assembly described in the embodiments of this application;

[0022] Figure 6 This is an assembly drawing of the internal gear assembly, bearing, and washer ring described in the embodiments of this application;

[0023] Figure 7 This is a perspective view of the internal gear ring described in the embodiment of this application.

[0024] In the diagram: 1. Stator assembly; 2. Rotor assembly; 201. Magnet; 202. Bracket; 2011. Magnetic yoke; 2012. Magnet; 2013. Mounting cavity; 3. Internal gear assembly; 301. Internal gear ring; 302. Fixing frame; 3011. Main ring body; 3012. Limiting part; 3013. First rack; 3014. Second rack; 3015. Assembly part; 4. Reduction assembly; 401. First stage reducer; 402. Second stage reducer; 5. Housing; 6. Accommodation space; 7. Bearing; 8. Washer ring. Detailed Implementation

[0025] To make the technical problems solved by this application, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] Currently, the demand for planetary reducers in the robotics industry continues to grow, especially in the fields of industrial and service robots. With their high torque density, compact structure, and excellent load capacity, planetary reducers have become a core component for robot joint actuation. With the rapid development of collaborative robots, humanoid robots, and mobile robots, the sensitivity to the size and weight of reducers has significantly increased. Traditional industrial robots focus more on precision and durability, while emerging applications require reducers to be further lightweight while maintaining performance, in order to adapt to flexible deployment and energy efficiency optimization needs.

[0029] However, in current planetary gear reducers, especially those with two or more stages, the internal gear ring accounts for a significant portion of the weight, exceeding 50%. This not only affects the overall power density and lifespan of the reducer but also easily leads to resonance problems, reducing operational smoothness and transmission accuracy. Since the gear ring material is typically limited to alloy steel due to strength limitations, further optimization in material density is not possible. Therefore, reducing the weight of the gear ring structurally has become a key challenge in the current technological field.

[0030] In existing technologies, planetary gear reducers typically place the internal gear assembly and reduction assembly outside the motor or independently of the rotor assembly. This layout results in a large overall motor size and suboptimal mass distribution. Furthermore, traditional planetary gear reducers fail to fully utilize the internal space of the rotor assembly, limiting the motor's compactness and lightweight design. Therefore, existing technologies have limitations in meeting the robotics industry's demands for lightweight, high-performance reducers.

[0031] In response to the above problems, such as Figures 1-7 As shown, this embodiment proposes a geared motor, including: a stator assembly 1, a rotor assembly 2, an internal gear assembly 3, and a reduction assembly 4. The rotor assembly 2 is disposed inside the stator assembly 1, and an accommodating space 6 is formed in the inner ring of the rotor assembly 2. The internal gear assembly 3 is at least partially located within the accommodating space 6. The reduction assembly 4 includes a first-stage reducer 401 and a second-stage reducer 402 coaxially arranged. The power output end of the rotor assembly 2 is drive-connected to the power input end of the first-stage reducer 401, and the power input end of the second-stage reducer 402 is drive-connected to the power output end of the first-stage reducer 401. The first-stage reducer 401 is disposed within the accommodating space 6 and meshes with the internal gear assembly 3. The second-stage reducer 402 is at least partially located within the accommodating space 6 and meshes with the internal gear assembly 3.

[0032] Based on the above scheme, the power transmission path is optimized by embedding the internal gear assembly 3 and the reduction assembly 4 at least partially into the accommodating space 6 formed by the inner ring of the rotor assembly 2. In terms of working principle, the rotor assembly 2 rotates under the drive of the stator assembly 1. Its power output end is connected to the power input end of the first-stage reducer 401, transmitting power to the first-stage reducer 401. The first-stage reducer 401 then transmits the power to the second-stage reducer 402. Through the reduction action of the first-stage and second-stage reducers 401, the high-speed rotating power is converted into a low-speed, high-torque output, thereby meeting the torque and speed requirements of different application scenarios. This design makes the motor's power transmission more efficient, reduces energy loss during transmission, and optimizes the internal space utilization of the motor.

[0033] In summary, by embedding the internal gear assembly 3 into the accommodating space 6, placing the first-stage reducer 401 within the accommodating space 6 and meshing it with the internal gear assembly 3, and placing the second-stage reducer 402 at least partially within the accommodating space 6 and meshing it with the internal gear assembly 3, the axial overlapping layout ensures that the installation depth of the internal gear assembly 3 and the reduction assembly 4 partially coincides with the axial length of the rotor assembly 2. This geometric superposition replaces the series arrangement, eliminating the isolation gaps between components in traditional designs and further compressing the axial space, resulting in a smaller axial dimension of the geared motor and achieving a compact structure. This compact structure leads to a reduction in the amount of material used for each structural component. For example, if the original axial length of the internal gear assembly 3 and the reduction assembly 4 is N, after compaction using this solution, the axial length of the internal gear assembly 3 and the reduction assembly 4 may be reduced to N / 2. Thus, while maintaining the same structural strength and material usage, the weight of the internal gear assembly 3 and the reduction assembly 4 is reduced. Similarly, the other structures of the motor achieve lightweighting due to the reduced axial dimensions, which not only reduces the overall weight of the motor but also improves portability and energy efficiency. Meanwhile, the compact design reduces energy loss during transmission, improving motor operating efficiency. Optimized mass distribution reduces vibration and noise, enhancing the smoothness and reliability of motor operation. Smaller size and weight allow the motor to adapt to a wider range of applications, including mobile robots and other space- and weight-sensitive devices. Furthermore, the compact design reduces material usage, lowers production costs, and enhances the product's market competitiveness.

[0034] In addition, in the above scheme, the internal gear assembly 3 and the reduction assembly 4 are partially disposed within the accommodating space 6. However, in an optional specific embodiment, the internal gear assembly 3 and the reduction assembly 4 can be disposed entirely within the accommodating space 6. If the motor is a single-stage reduction motor, the axial dimensions of the internal gear assembly 3 and the reduction assembly 4 are designed to be relatively small. In this case, the internal gear assembly 3 and the reduction assembly 4 can be disposed entirely within the accommodating space 6, thereby ensuring that the axial dimensions of the motor are compact.

[0035] Furthermore, the rotor assembly 2 includes a magnet 201 and a bracket 202. The magnet 201 is located inside the stator assembly 1, and its interior has a mounting cavity 2013. A portion of the mounting cavity 2013 is tightly fitted onto the outer peripheral wall of the bracket 202, which provides fixation and support for the magnet 201. The remaining portion of the mounting cavity 2013 serves as a receiving space 6, in which the internal gear assembly 3 and the reduction assembly 4 are embedded, achieving space sharing among multiple key components. This design not only improves the internal space utilization of the motor but also makes the entire motor structure more compact, helping to further reduce the motor's weight and volume, improve its energy efficiency, and reduce material usage and production costs. Simultaneously, the bracket 202 not only supports the magnet 201 but also connects to the power input end of the first-stage reducer 401, ensuring that the rotational power of the rotor assembly 2 is efficiently transmitted to the first-stage reducer 401.

[0036] Crucially, rotor assembly 2 not only improves the utilization efficiency of the magnetic field but also significantly optimizes the internal spatial layout of the motor. The accommodating space 6 formed by the inner ring of magnet 201 provides the possibility of embedded installation of internal gear assembly 3 and reduction assembly 4, reducing the occupation of external space, making the overall structure of the motor more compact, effectively reducing the overall weight of the motor without affecting its operation.

[0037] In some embodiments, the system further includes a housing 5. The internal gear assembly 3 includes an internal gear ring 301 and a fixing frame 302. The fixing frame 302 is located within the accommodating space 6. The internal gear ring 301 is fitted onto the outer periphery of the first-stage reducer 401 and meshes with it. The internal gear ring 301 is also fitted onto at least a portion of the outer periphery of the second-stage reducer 402 and meshes with it, ensuring the smoothness and accuracy of power transmission. One end of the internal gear ring 301 is fixedly connected to the housing 5, and the other end is connected to the fixing frame 302. This fixed connection effectively prevents circumferential wobbling during the rotation of the reduction assembly 4, ensuring the stability of the transmission ratio and thus improving the smoothness and accuracy of motor operation. Furthermore, the internal gear ring 301 can be fitted onto a portion of the outer periphery of the second-stage reducer 402, or, depending on the actual design, can be fitted onto the entire outer periphery of the second-stage reducer 402.

[0038] It is important to note that the structural strength of the internal gear ring 301 is greater than that of the fixed frame 302. As the core force-transmitting component of the planetary reducer, the internal gear ring 301 is made of high-strength alloy steel. Precision machining and heat treatment processes ensure its tooth surface hardness and fatigue resistance, directly bearing the dynamic load during gear meshing. Its rigid connection with the housing 5 forms a stable constraint boundary, ensuring transmission accuracy. The fixed frame 302, as a non-load-bearing support structure, is made of lightweight aluminum alloy. A hollow frame is formed through topology optimization design, achieving lightweighting by utilizing the low density of aluminum alloy while maintaining necessary connection strength. The fixed frame 302 and the internal gear ring 301 are designed separately but connected, satisfying the high strength requirements of the internal gear ring 301 while dispersing local stress through the lightweight structure of the fixed frame 302. Through functional zoning design, the force transmission path is concentrated in the meshing area of ​​the internal gear ring 301, while the fixed frame 302 only undertakes auxiliary positioning and structural support functions, achieving directional adaptation of material properties. Furthermore, the internal gear ring 301 and the fixing bracket 302 are detachable, meaning these two parts are independent components before assembly and can be machined separately, reducing processing difficulty. At the same time, it facilitates disassembly for inspection or replacement in case of problems after use. Replacement can be done by replacing a single internal gear ring 301 or the fixing bracket 302, without needing to replace the entire unit, effectively reducing maintenance costs.

[0039] Through partitioned material matching design, the high strength of the internal gear ring 301 ensures wear resistance and transmission stability in the gear meshing area, effectively preventing tooth surface failure caused by alternating loads. The lightweight structure of the fixed frame 302 significantly reduces the overall mass, while its optimized geometry suppresses vibration transmission and improves heat dissipation efficiency. The synergistic design of these two components achieves weight reduction while maintaining system stiffness, solving the problem of excessive mass in traditional all-steel structures and avoiding the deficiency of insufficient strength in single lightweight materials, thus comprehensively improving the power density and dynamic response characteristics of the reducer.

[0040] Furthermore, the material for the 301 internal gear ring is not limited to steel; aluminum alloys and plastics can also be used to adapt to different application scenarios. The material selection for the 301 internal gear ring dynamically adapts to the application scenario: in high-load scenarios such as industrial robots, steel 301 internal gear rings are used, with heat treatment and surface hardening processes ensuring fatigue strength of the tooth surface; in light-load scenarios such as collaborative robots, aluminum alloy 301 internal gear rings achieve strength-weight balance through topological reinforcement ribs and local nitriding treatment; in low-load and corrosion-resistant scenarios such as food and medical applications, engineering plastic (such as PEEK or carbon fiber reinforced nylon) 301 internal gear rings are injection molded, utilizing fiber orientation to optimize tooth root bending stiffness. Gear rings made of different materials are designed with tooth profile parameters based on load spectrum characteristics—steel gear rings use full-depth meshing, aluminum alloy gear rings use tapered tooth roots, and plastic gear rings use a double pressure angle design to compensate for elastic deformation, ensuring meshing stability in various scenarios.

[0041] A multi-material adaptation strategy significantly expands the application boundaries of reducers: 301 steel internal gear rings maintain reliability and lifespan under heavy-duty scenarios; aluminum alloy solutions reduce the weight of joint modules by 30%-40%, meeting the collision safety requirements of collaborative robots; plastic gear rings achieve electromagnetic isolation and oil-free self-lubrication, adapting to clean environments and reducing maintenance costs. Through material-structure co-design, the same reducer platform can be quickly switched to adapt to different industry needs. For example, medical robots use plastic gear rings to avoid metal debris contamination, while AGV drive wheels use aluminum alloy gear rings to optimize energy efficiency. This flexible design breaks through the limitations of traditional reducer material rigidity, providing underlying technical support for modular robot development.

[0042] It is worth noting that in the above scheme, the arrangement of the rotor assembly 2 inside the stator assembly 1 includes at least two cases. The first case is where the rotor assembly 2 is partially located inside the stator assembly 1, meaning the magnet 201 is entirely located within the inner ring of the stator assembly 1, while the support 202 partially protrudes axially. This can be understood as a portion of the support 202 structure protruding from the side of the stator assembly 1. This protruding portion of the support 202 is connected to the housing 5 for transmission, allowing the support 202 and magnet 201 to rotate relative to the housing 5. The second case is where both the magnet 201 and the support 202 are located inside the stator assembly 1, meaning the support 202 no longer protrudes from the side of the stator assembly 1. In this case, to achieve the power transmission connection between the support 202 and the housing 5, the housing 5 needs to extend into the stator assembly 1 to connect with the support 202.

[0043] Meanwhile, the magnet 201 includes a ring-shaped magnetic yoke 2011 and multiple magnets 2012 spaced apart on the outer surface of the yoke 2011. The ring-shaped design of the yoke 2011, as the basic structure of the magnet 201, ensures a uniform magnetic field distribution, guaranteeing its stability and consistency. The multiple magnets 2012 spaced apart on the outer surface of the yoke 201 form a complete magnetic circuit. This structure enables the magnet 201 to generate a uniform and strong magnetic field within the stator assembly 1, thereby interacting with the windings in the stator assembly 1 when energized to generate electromagnetic torque, driving the rotor assembly 2 to rotate. Furthermore, the specific structure of the magnet 201 can be adjusted according to actual design requirements, and is not limited to the aforementioned specific structure.

[0044] Furthermore, a bearing 7 is provided between the power output end of the reduction assembly 4 and the internal gear ring 301. The outer ring of the bearing 7 is clearance-fitted to the internal gear ring 301, and the inner ring is interference-fitted to the power output end of the secondary reducer 402. The bearing 7, with its outer ring connected to the internal gear ring 301 via a clearance fit, allows for slight radial displacement of the outer ring under thermal expansion or dynamic loads, avoiding assembly stress caused by dimensional changes. The inner ring, however, is rigidly connected to the power output end via an interference fit, ensuring the synchronicity of power transmission and the stability of torque bearing. In this configuration, the bearing 7 simultaneously provides radial support and axial restraint. The clearance fit of the outer ring releases the deformation constraint of the internal gear ring 301 caused by temperature rise or vibration, while the interference fit of the inner ring maintains the coaxial accuracy of the output shaft system, forming a "flexible outside, rigid inside" composite support structure that balances load distribution and reduces friction loss under dynamic operating conditions.

[0045] Furthermore, the internal gear ring 301 includes a main ring body 3011 and multiple spaced limiting portions 3012 protruding from the outer edge of the main ring body 3011 opposite to the bearing 7. The inner side of the limiting portion 3012 is in clearance fit with the outer ring of the bearing 7, and the internal gear ring 301 is fixedly connected to the housing 5 through the limiting portions 3012. The main ring body 3011 of the internal gear ring 301 serves as the gear meshing body, and the spaced limiting portions 3012 on its outer edge provide multi-point rigid connection while achieving lightweight design by removing redundant material in the non-limiting areas of the main ring body 3011. The spaced layout of the limiting portions 3012 retains the contact area required for fixed connection with the housing 5, and significantly reduces ineffective mass by hollowing out the rest of the main ring body 3011; the clearance fit between the inner side of the limiting portion 3012 and the outer ring of the bearing 7 allows for slight displacement caused by thermal expansion and vibration, while the frame-like support structure formed by the discrete limiting points maintains circumferential stiffness while reducing weight. Moreover, the removal of redundant materials reduces material costs and processing energy consumption, providing a fundamental support for the design of high power density reducers.

[0046] Specifically, the number of limiting parts 3012 can be designed as three, four, five, six, or more, depending on actual design requirements. The number of limiting parts 3012 is dynamically configured based on load characteristics and spatial constraints: three limiting parts 3012 form a triangular stable support, suitable for lightweight mobile robot scenarios; four limiting parts 3012 form a symmetrical cross layout to evenly bear the load, adapting to the uniform load requirements of conventional industrial scenarios; five or six limiting parts 3012 are densely distributed in polygons to achieve multi-point vibration mode suppression in high-vibration environments such as aerospace. The number and layout of limiting parts 3012 are generated based on finite element topology optimization results, and the local stiffness is adjusted by increasing or decreasing the number of nodes—when the number is small, the main ring 3011 absorbs the impact through flexible deformation; when the number is large, a rigid network is formed to resist high-frequency vibration. At the same time, all schemes retain the clearance fit characteristics between the inner side of the limiting part 3012 and the bearing 7 to ensure thermal deformation compensation capability. Specifically, the limiting part 3012 is claw-shaped.

[0047] Furthermore, one end face of the bearing 7 abuts against the inner wall of the housing 5, and the other end face faces the end face of the main ring 3011, with a washer 8 positioned between them. One end face of the bearing 7 contacts the inner wall of the housing 5 to form an axial positioning reference, while the other end face, through the washer 8, forms an adjustable preload interface with the end face of the main ring 3011. The annular structure of the washer 8 is coupled with the spatial distribution of the limiting part 3012. During assembly, tightening the connecting bolts of the limiting part 3012 generates axial clamping force, causing the washer 8 to undergo elastic deformation. Simultaneously, it pushes the outer ring of the bearing 7 and the inner clearance mating surface of the limiting part 3012 to form a radial constraint. This bidirectional preload mechanism utilizes the discrete fulcrum of the limiting part 3012 as a force carrier, converting the bolt tightening force into a precise preload between the inner and outer rings of the bearing 7, achieving coordinated control of axial clearance elimination and radial runout suppression. Simultaneously, the elastic characteristics of the washer 8 can compensate for thermal expansion differences during operation.

[0048] Meanwhile, the outer edge of the main ring body 3011 opposite to the bearing 7 has multiple protruding assembly parts 3015 at intervals. The fixing frame 302 is located inside the assembly parts 3015 and is locked by fasteners. The assembly parts 3015 spaced apart on the outer edge of the main ring body 3011 opposite to the bearing 7 form discrete connection nodes. The fixing frame 302 is locked inside the assembly parts 3015 by the ring-shaped fasteners. The spaced layout of the assembly parts 3015 eliminates the redundant mass of the continuous flange structure while ensuring connection rigidity. At the same time, the pre-tightening force of the fasteners forms a closed force flow loop between the fixing frame 302 and the main ring body 3011. The lightweight frame of the fixing frame 302 is embedded in the inner space enclosed by the assembly parts 3015 of the main ring body 3011. The radial clamping force applied by the bolt group causes the fixing frame 302 and the main ring body 3011 to have surface contact friction constraint, which achieves both axial positioning and torsional rigidity.

[0049] The design of the spacer assembly section 3015 combines localized reinforcement with large-area hollowing to enable the interface between the fixed bracket 302 and the internal gear ring 301 to have adaptive deformation compensation capability. The modular assembly structure allows the fixed bracket 302 to be pre-assembled independently and then embedded as a whole, significantly improving assembly efficiency and reducing sensitivity to cumulative machining errors. This layout concentrates the load to the node area of ​​the assembly section 3015 through mechanical path optimization, avoiding unnecessary structural participation in stress, achieving a deep synergy between lightweight and high reliability, and providing a structural basis for rapid maintenance and component replacement of the reducer under complex operating conditions.

[0050] Specifically, the inner side of the main ring body 3011 is provided with a first rack 3013 and a second rack 3014 that are interconnected. The first rack 3013 and the second rack 3014 are arranged at intervals, and the first rack 3013 and the second rack 3014 can be integrally formed by molding the main ring body 3011. The first rack 3013 meshes with the first-stage reducer 401, and the second rack 3014 meshes with the second-stage reducer 402. When the rotor assembly 2 rotates, its power is first transmitted to the first-stage reducer 401, where the first rack 3013 performs the first deceleration. Subsequently, the decelerated power is transmitted to the second-stage reducer 402, where the second rack 3014 performs the second deceleration. This combination of double racks and two-stage reducers achieves gradual deceleration of power and gradual increase of torque, ultimately outputting low-speed, high-torque power to meet the needs of different application scenarios. This design utilizes a double rack on the main ring 3011 to mesh with the first-stage reducer 401, the second-stage reducer 402, and the third-stage reducer 401, allowing both reducers to share a single internal gear ring 301. This layout effectively reduces the overall weight of the motor, as well as the amount of material used, thus lowering production costs. Furthermore, the partitioned load-bearing design of the double rack allows for precise matching of the material's strength threshold to different load stages, preventing excessive material usage and improving material utilization. More importantly, this design reduces the risk of vibration coupling, resulting in smoother motor operation, reduced vibration and noise, and ultimately improved motor reliability and lifespan.

[0051] As an optional specific implementation scheme, the reduction assembly 4 adopts a modular hierarchical design. When the basic configuration uses a single-stage reducer, only the first rack 3013 is set on the inner side of the internal gear assembly 3, and the basic reduction ratio is achieved through a single-layer planetary gear train. When extended to a three-stage reduction, the second and third racks are added in layers on the inner side of the internal gear ring 301. Each rack independently meshes with the planetary gear set, forming a series power transmission chain. Each stage of the reducer shares a coaxial spatial layout, and the reduction ratio is adjusted in a stepwise manner by increasing or decreasing the number of rack layers. The internal gear ring 301 body serves as the integrated carrier of multiple meshing surfaces, and adopts an axially stacked or radially nested rack distribution method to complete the topological integration of multi-stage reduction functions within a limited space.

[0052] It is worth mentioning that the tooth structure is only retained in the meshing area of ​​the first rack 3013 and the second rack 3014 on the inner side of the internal gear assembly 3. The non-meshing area is designed as a flat curved surface. The body weight of the internal gear ring 301 is achieved by removing redundant material in the middle. The hollowed-out design of the non-meshing area significantly reduces the rotational inertia of the internal gear ring 301 and reduces energy loss during high-speed commutation. At the same time, the continuous shell formed by the flat curved surface maintains the overall bending stiffness and avoids the risk of dynamic deformation caused by weight reduction. The further functional partitioning of the rack and the curved surface allows for precise matching of material distribution and load path, improving the specific strength and specific stiffness of the internal gear ring 301. In addition, this flat curved surface can be achieved by slotting or cutting out the area between the first rack 3013 and the second rack 3014.

[0053] In summary, through the aforementioned weight reduction design, the internal gear assembly 3 achieves a final weight reduction of 30%-40%, while increasing the overall power density by over 15%. The internal gear assembly 3 significantly reduces inertial load while maintaining fatigue resistance. Combined with the space reuse strategy of the coaxial reducer, the entire machine overcomes the volume limitations of traditional planetary reducers, achieving a deep synergy between lightweight design and high power density. Simultaneously, the overall structure is more compact, with an axial dimension reduced by 20%-30%, making it suitable for space-sensitive applications such as humanoid robot joints and surgical robotic arms.

[0054] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and other orientations or positional relationships are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no special meaning.

[0055] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0057] The technical principles of this application have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this application without inventive effort, and these embodiments will all fall within the scope of protection of this application.

Claims

1. A geared motor, characterized in that, include: The stator assembly (1), rotor assembly (2), internal gear assembly (3), and reduction assembly (4) are provided. The rotor assembly (2) is disposed inside the stator assembly. The inner ring of the rotor assembly (2) forms an accommodating space (6). The internal gear assembly (3) is at least partially located within the accommodating space (6). The reduction assembly (4) includes a first-stage reducer (401) and a second-stage reducer (402) coaxially disposed. The power output end of the rotor assembly (2) is drivenly connected to the power input end of the first-stage reducer (401). The power input end of the second-stage reducer (402) is drivenly connected to the power output end of the first-stage reducer (401). The first-stage reducer (401) is disposed within the accommodating space (6) and meshes with the internal gear assembly (3). The second-stage reducer (402) is at least partially located within the accommodating space (6) and meshes with the internal gear assembly (3).

2. The geared motor according to claim 1, characterized in that, The rotor assembly (2) includes a magnet (201) and a bracket (202). The magnet (201) is disposed inside the stator assembly. The magnet has a mounting cavity. A portion of the mounting cavity is fitted onto the outer peripheral wall of the bracket. The remaining portion of the mounting cavity forms the accommodating space. The bracket (202) is connected to the power input end of the first-stage reducer (401).

3. The geared motor according to claim 1, characterized in that, It also includes a housing (5), and the internal gear assembly (3) includes an internal gear ring (301) and a fixing frame (302). The fixing frame (302) is located in the accommodating space. The internal gear ring (301) is sleeved on the outer periphery of the first-stage reducer (401) and meshes with the first-stage reducer (401). The internal gear ring (301) is sleeved on at least part of the outer periphery of the second-stage reducer (402) and meshes with the second-stage reducer (402). One end of the internal gear ring (301) is fixedly connected to the housing (5), and the other end of the internal gear ring (301) is connected to the fixing frame (302).

4. The geared motor according to claim 3, characterized in that, The internal gear ring (301) has a greater structural strength than the fixed frame (302), and the internal gear ring (301) and the fixed frame (302) are detachably connected to each other.

5. The geared motor according to claim 3, characterized in that, A bearing (7) is provided between the power output end of the reduction assembly (4) and the internal gear ring (301). The outer ring of the bearing (7) is clearance-fitted with the internal gear ring (301), and the inner ring of the bearing (7) is interference-fitted with the power output end of the secondary reducer (402).

6. The geared motor according to claim 5, characterized in that, The internal gear ring (301) includes a main ring body (3011) and a plurality of limiting portions (3012) spaced apart and protruding from the outer edge of the main ring body (3011) on the side opposite to the bearing (7). The inner side of the limiting portion (3012) is in clearance fit with the outer ring of the bearing (7). The main ring body (3011) is fixedly connected to the housing (5) through the limiting portion (3012).

7. The geared motor according to claim 6, characterized in that, One end face of the bearing (7) abuts against the inner wall of the housing (5), and the other end face of the bearing (7) is opposite to the end face of the main ring body (3011). A washer (8) is provided between the bearing (7) and the main ring body (3011).

8. The geared motor according to claim 6, characterized in that, The main ring body (3011) has a plurality of mounting parts (3015) protruding at intervals on the outer edge of the side opposite to the bearing (7), and the fixing frame (302) is located inside the mounting parts (3015) and locked by fasteners.

9. The geared motor according to claim 6, characterized in that, The inner side of the main ring body (3011) is provided with a first rack (3013) and a second rack (3014) that are connected to each other. The first rack (3013) and the second rack (3014) are arranged at intervals. The first rack (3013) meshes with the first-stage reducer (401), and the second rack (3014) meshes with the second-stage reducer (402).

10. The geared motor according to claim 9, characterized in that, The inner non-meshing area of ​​the main ring (3011) is a flat curved surface.

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