An ultra-thin planetary gear reducer

Abstract

The application relates to an ultra-thin planetary gear reducer, which comprises the following steps: a gear ring is coaxially sleeved outside a sun gear, and an inner ring wall of the gear ring is provided with an inner gear ring; a planetary carrier assembly comprises a first planetary carrier and a second planetary carrier which are oppositely arranged along the thickness direction of the gear ring, the first planetary carrier is arranged corresponding to the inner gear ring, the second planetary carrier is connected with the first planetary carrier, and the first planetary carrier and the gear ring jointly enclose a planetary gear mounting cavity together; a plurality of planetary gears are uniformly distributed in the planetary gear mounting cavity in the circumferential direction, and each planetary gear is simultaneously engaged with the inner gear ring and the sun gear; a mounting ring is arranged at the end of the gear ring, and at least a part of the second planetary carrier is accommodated in the inner hole of the mounting ring. Through the nested space layout and the split rigid support of the planetary carrier assembly, various functional components are organically combined in a compact manner, the axial size is extremely compressed, and the functions of speed reduction and torque increase are efficiently and stably realized in the extremely small axial space.

Description

Technical Field

[0001] This application relates to the field of planetary gear reducer technology, and in particular to an ultra-thin planetary gear reducer. Background Technology

[0002] Planetary gear reducers are highly favored for their numerous advantages, including small size, light weight, high load capacity, long service life, smooth operation, low noise, high output torque, large speed ratio, high efficiency, and safe performance. As more and more companies use planetary gear reducers, market demands are constantly increasing. In addition to stringent requirements on load capacity, service life, and manufacturing precision, space constraints and dimensional limitations have become more stringent, forcing the abandonment of planetary gear reducers in many operating conditions.

[0003] Currently, the main speed reduction products on the market that can meet the requirements of high reduction ratio and small size are RV speed reducers and harmonic speed reducers. However, these two types of speed reducers have obvious limitations: First, their core technologies and high-end markets have long been monopolized by foreign companies, resulting in high product prices and unstable supply cycles; second, even speed reducers designed for compact spaces cannot meet the requirements in certain extreme working conditions, and their high manufacturing costs limit their large-scale application in popular products where cost control is strict.

[0004] Faced with this contradiction, traditional general-purpose planetary gearboxes are limited by their own structural layout, making it difficult to further reduce their thickness. This forces many working conditions with ultra-thin requirements to abandon high-performance planetary solutions or make compromises in the overall machine design. Utility Model Content

[0005] This application provides an ultra-thin planetary gear reducer. By using a first planetary carrier and a second planetary carrier that are arranged opposite to each other along the thickness direction of the gear ring and a design that accommodates part of the second planetary carrier in the inner hole of the mounting ring, the axial dimension (thickness) of the reducer is greatly reduced. This allows the reducer to be made thinner, saving space and achieving a high reduction ratio, low noise, and stable operation.

[0006] Therefore, this application provides an ultra-thin planetary gear reducer, comprising:

[0007] Sun wheel;

[0008] A gear ring is coaxially sleeved on the outside of the sun gear, and the inner ring wall of the gear ring is provided with an inner gear ring;

[0009] The planetary carrier assembly includes a first planetary carrier and a second planetary carrier disposed opposite to each other along the thickness direction of the gear ring. The first planetary carrier is disposed corresponding to the internal gear ring, and the second planetary carrier is connected to the first planetary carrier and together with the first planetary carrier and the gear ring, forms a planetary gear mounting cavity.

[0010] Multiple planetary gears are evenly distributed circumferentially within the planetary gear mounting cavity, and each planetary gear simultaneously meshes with both the internal gear ring and the sun gear.

[0011] A mounting ring is disposed at the end of the gear ring, and at least a portion of the second planetary carrier is accommodated in the inner hole of the mounting ring.

[0012] As a preferred embodiment, the sun gear passes through the center of the first planet carrier and the second planet carrier in sequence. The second planet carrier has a mounting groove on the side facing the first planet carrier, and the sun gear is supported in the mounting groove of the second planet carrier by a first bearing.

[0013] As a preferred embodiment, the gear ring has an assembly groove at one end near the second planetary carrier, and the mounting ring has a radially inward extension on the side facing the second planetary carrier. The extension, the assembly groove, and the outer peripheral surfaces of the first and second planetary carriers form an annular bearing mounting cavity, and a second bearing is provided inside the bearing mounting cavity.

[0014] As a preferred embodiment, the end of the first planetary carrier facing the second planetary carrier is provided with a first step, and the end of the second planetary carrier facing the first planetary carrier is provided with a second step that matches the first step; wherein, the first step and the second step engage to achieve radial positioning and connection between the first planetary carrier and the second planetary carrier.

[0015] As a preferred embodiment, the side of the second step facing the bearing mounting cavity abuts against the inner ring of the second bearing.

[0016] As a preferred embodiment, the sun gear sleeve is provided with a transition sleeve, which is supported by a third bearing on the side of the first planetary carrier opposite to the second planetary carrier.

[0017] As a preferred embodiment, the outer end face of the second planetary carrier is provided with a floral groove along its axial direction.

[0018] As a preferred embodiment, the outer end face of the second planetary carrier has an axial threaded hole for fixing the corresponding working machine, and the working machine and the outer end face of the mounting ring cooperate to form a positioning stop.

[0019] As a preferred embodiment, each planetary gear is fitted onto a corresponding planetary shaft, and the two ends of the planetary shaft are respectively fixed to the first planetary carrier and the second planetary carrier.

[0020] As a preferred embodiment, the first bearing, the second bearing, and the third bearing are all ultra-thin deep groove ball bearings.

[0021] The beneficial effects of this application are:

[0022] This ultra-thin planetary gear reducer includes a sun gear, a ring gear, a planet carrier assembly, multiple planet gears, and a mounting ring. The ring gear is coaxially sleeved on the outside of the sun gear, and the inner ring wall of the ring gear has an inner ring gear. The planet carrier assembly includes a first planet carrier and a second planet carrier arranged opposite to each other along the thickness direction of the ring gear. The first planet carrier is arranged corresponding to the inner ring gear, and the second planet carrier is connected to the first planet carrier and together with the first planet carrier and the ring gear, forms a planet gear mounting cavity. Multiple planet gears are evenly distributed circumferentially within the planet gear mounting cavity, and each planet gear simultaneously meshes with both the inner ring gear and the sun gear. The mounting ring is located at the end of the ring gear, and at least a portion of the second planet carrier is accommodated in the inner hole of the mounting ring.

[0023] Through nested spatial layout and split rigid support of planetary carrier components, various functional components are organically combined in a compact manner, achieving extreme compression of axial dimensions. Within a very small axial space, the function of deceleration and torque increase is achieved efficiently and stably. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This application provides a structural schematic diagram of an ultra-thin planetary gear reducer.

[0026] Figure 2 for Figure 1 Cross-sectional structural diagram;

[0027] Figure 3 for Figure 2 A magnified view of part A in the image;

[0028] Figure 4 for Figure 2 A magnified view of part B in the image;

[0029] Figure 5 for Figure 1Another cross-sectional structural diagram;

[0030] Figure 6 for Figure 5 Side view structural diagram;

[0031] Figure 7 for Figure 1 A schematic diagram of the inner ring structure.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Sun gear; 2. Transition sleeve; 3. Gear ring; 31. Internal gear ring; 32. Assembly slot; 4. Mounting ring; 41. Extension; 51. First planetary carrier; 511. First step; 52. Second planetary carrier; 521. Flower-shaped groove; 522. Second step; 523. Mounting slot; 61. First bearing; 62. Second bearing; 63. Third bearing; 7. Planet gear; 8. Planetary shaft; 9. Screw. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0036] like Figures 1 to 7As shown, this application provides an ultra-thin planetary gear reducer, including a sun gear 1, a ring gear 3, a planet carrier assembly, a plurality of planet gears 7, and a mounting ring 4; the ring gear 3 is coaxially sleeved on the outside of the sun gear 1, and the inner ring wall of the ring gear 3 is provided with an inner ring gear 31; the planet carrier assembly includes a first planet carrier 51 and a second planet carrier 52 arranged opposite to each other along the thickness direction of the ring gear 3, the first planet carrier 51 is arranged corresponding to the inner ring gear 31, and the second planet carrier 52 is connected to the first planet carrier 51 by an axial screw 9, and together with the first planet carrier 51 and the ring gear 3, they form a mounting cavity for the planet gears 7; the plurality of planet gears 7 are evenly distributed circumferentially in the mounting cavity for the planet gears 7, and each planet gear 7 simultaneously meshes with the inner ring gear 31 and the sun gear 1; the mounting ring 4 is provided at the end of the ring gear 3, and at least a portion of the second planet carrier 52 is accommodated in the inner hole of the mounting ring 4.

[0037] The planetary carrier assembly is designed as a split structure, with the first planetary carrier 51 and the second planetary carrier 52 positioned opposite each other along the thickness direction of the gear ring 3. They are connected axially via screws 9, resulting in a compact structure that significantly saves radial space. This allows the planetary carrier assembly to be made very thin, ensuring structural strength and rigidity to withstand output torque without significantly increasing radial thickness. The first planetary carrier 51 and the second planetary carrier 52, together with the gear ring 3, form a closed mounting cavity for the planetary gears 7, encapsulating all transmission components within a compact space. This clamps the planetary gears 7 from both sides, providing stable and precise radial and axial positioning, ensuring gear meshing accuracy, reducing noise and vibration, and improving transmission efficiency. It is known that the split, two-piece planetary carrier assembly structure is easier to manufacture than a complex, integral planetary carrier, especially during assembly, where the planetary gears 7 can be installed on one planetary carrier first, then the other carrier can be replaced and screws 9 tightened, making the operation more flexible.

[0038] The mounting ring 4 is located at the end of the gear ring 3. By nesting at least a portion of the second planetary carrier 52 into the internal space of the mounting ring 4, the two components partially overlap in the axial direction, rather than simply being arranged one in front of the other, thus maximizing the compression of the axial dimension. This directly reduces the overall thickness of the reducer, a key step in achieving an ultra-thin reducer. Simultaneously, the inner hole of the mounting ring 4 provides auxiliary support and guidance for the outer circle of the second planetary carrier 52, further ensuring the coaxiality of the planetary carrier assembly with the gear ring 3 and sun gear 1, significantly improving the coaxiality and torsional stiffness of the entire system, and reducing vibration and noise. Furthermore, the mounting ring 4 integrates the gear ring 3, planetary carrier assembly, and other components into a complete module, allowing the reducer to be fixedly connected to external equipment (such as a motor or working machine) via bolts or other means. Its internal nesting structure also participates in the positioning of the internal components.

[0039] The gear ring 3 is coaxially mounted on the outside of the sun gear 1. Its inner ring wall has internal teeth that mesh with the planet gears 7. As the basic frame of the entire transmission system, it provides the mounting reference for the planet carrier assembly and the mounting ring 4. At the same time, as a fixed component, the gear ring 3 bears most of the reaction torque transmitted from the planet gears 7. In addition, the gear ring 3 and the planet carrier assembly together form a closed mounting cavity for the planet gears 7, protecting the internal gears from external contamination and accommodating lubricating oil.

[0040] In other words, by using a nested spatial layout and a split rigid support for the planetary carrier assembly, the various functional components are organically combined in a compact manner, achieving extreme compression of the axial dimension. Within a very small axial space, the function of deceleration and torque increase is achieved efficiently and stably.

[0041] In this embodiment, as Figure 1 As shown, the mounting ring 4 has evenly distributed through holes around its circumference, and the gear ring 3 has evenly distributed threaded holes around its circumference. The axial screw 9 passes through the mounting ring 4 axially and is fixed to the evenly distributed threaded holes on the gear ring 3. The mounting ring 4 is firmly fixed to the end face of the gear ring 3 by the axial screw 9, so that they are combined into a high-rigidity base frame.

[0042] The through hole on the mounting ring 4 for fixing to the gear ring 3 is a countersunk hole. The countersunk hole allows the head of the screw 9 to be recessed into the mounting ring 4, avoiding the screw head from protruding from the surface of the mounting ring 4, saving axial space, thereby minimizing the overall size of the reducer in the axial (thickness direction); secondly, the flat surface allows the reducer to fit more tightly to the motor or working machine without interference.

[0043] The mounting ring 4 is further provided with multiple through holes, which correspond one-to-one with the threaded holes evenly distributed on the gear ring 3. These through holes are used to connect the fixed part of the external working machine, thereby directly connecting the fixed part of the reducer (i.e., gear ring 3) and the fixed part of the external working machine. This eliminates the need for users to design additional connectors or adapter plates; installation can be completed directly using these standardized hole positions, greatly improving installation convenience and standardization. Furthermore, this design allows the reaction force from the working machine to be directly transmitted to the robust gear ring 3 through the mounting ring 4, resulting in a short force flow path and good structural rigidity.

[0044] The mounting ring 4 is provided with evenly distributed pin holes, which are used when the radial positioning of the external working machine is insufficient, thus ensuring the long-term stability of the connection between the reducer and the working machine.

[0045] The gear ring 3 has multiple threaded holes in the radial direction for mounting non-standard motor housings. That is, the non-standard motor housing is directly locked to the side of the gear ring 3 by radial screws 9. This is equivalent to embedding or attaching part of the motor housing into the radial space of the reducer, rather than stacking it in the axial direction, further saving axial space, thereby minimizing the total length of the motor-reducer combination.

[0046] It is clear that by using countersunk holes and radial motor connections, unnecessary axial thickness is eliminated from two directions; a robust housing is formed by the strong connection between mounting ring 4 and gear ring 3, and the pin hole design resists complex forces, ensuring high rigidity and precision despite the ultra-thin size; in addition, the connection holes integrated on mounting ring 4 and radial motor connection holes on gear ring 3 enable plug-and-play modular installation, reducing the installation complexity for users.

[0047] In this embodiment, as Figure 2 As shown, the sun gear 1 passes through the center of the first planetary carrier 51 and the second planetary carrier 52 in sequence. The second planetary carrier 52 has a mounting groove 523 on the side facing the first planetary carrier 51. The sun gear 1 is supported in the mounting groove 523 of the second planetary carrier 52 by the first bearing 61.

[0048] The first bearing 61 is installed in the mounting slot 523 carved out inside the second planetary carrier 52. The first bearing 61 serves as a support for the sun gear 1, ensuring the concentricity and stability of the input shaft rotation. Since the first bearing 61 is installed within the mounting slot 523 of the second planetary carrier 52 (i.e., within the thickness of the second planetary carrier 52 itself), it does not occupy additional axial space outside the second planetary carrier 52. Most of its volume is accommodated within the second planetary carrier 52, thus directly shortening the total length from the input end of the sun gear 1 to the rear end face of the second planetary carrier 52, maximizing space utilization and achieving axial thinning. Simultaneously, a first support point is formed at the center hole of the first planetary carrier 51 (usually with a sliding bearing or ball bearing), and a second support point is formed within the mounting slot 523 of the second planetary carrier 52. This two-point support structure greatly reduces the bending deformation of the sun gear 1 under meshing stress, lowers the stress on each support point, and improves the overall structural lifespan and reliability, thereby ensuring the precise and stable meshing between the sun gear 1 and all planet gears 7.

[0049] In other words, by concealing the first bearing 61 within the mounting slot 523 of the second planetary carrier 52 and allowing the sun gear 1 to pass through both planetary carriers, a highly rigid statically determinate support system is constructed using the shortest force flow path (sun gear 1 → two-point support → planetary carrier / gear ring 3 frame). Furthermore, the overall structure's ultra-thin profile and high rigidity are enhanced without increasing any axial dimensions.

[0050] In this embodiment, as Figure 3 As shown, the gear ring 3 has an assembly groove 32 at one end near the second planetary carrier 52, and the mounting ring 4 has a radially inward extension 41 on the side facing the second planetary carrier 52. The extension 41, the assembly groove 32, the outer peripheral surfaces of the first planetary carrier 51 and the second planetary carrier 52 form an annular bearing mounting cavity, and the bearing mounting cavity contains a second bearing 62. When the mounting ring 4 and the gear ring 3 are fixed by bolts or interference fit, the extension 41, the assembly groove 32, the outer ring of the first step 511 of the first planetary carrier 51, and the outer ring of the second step 522 of the second planetary carrier 52 together form a bearing mounting cavity. That is, the outer ring of the second bearing 62 is pressed tightly between the bottom surface of the assembly groove 32 of the gear ring 3 and the extension 41 of the mounting ring 4, and axial fixation is achieved by the bolt preload of the mounting ring 4. Its inner ring is interference-fitted with the outer circumferential surfaces of the first planetary carrier 51 and the second planetary carrier 52 to ensure that the inner ring of the second bearing 62 rotates synchronously when the planetary carrier assembly rotates. Moreover, the rollers of the second bearing 62 directly bear the radial load of the planetary carrier assembly and transfer it to the rigid shell composed of the gear ring 3 and the mounting ring 4, forming a three-point support system (sun gear 1 bearing, planetary carrier bearing, and fixed gear ring 3), which significantly improves the system's resistance to deformation.

[0051] During assembly, the second bearing 62 can be press-fitted onto the second planetary carrier 52 first, and then the first planetary carrier 51 and the second planetary carrier 52 can be connected by axial screws 9. At this time, the second bearing 62 has been initially positioned by the two planetary carriers. Finally, the entire planetary carrier assembly is installed into the gear ring 3 and the mounting ring 4 is covered. The final pressing of the bearing is completed by the extension 41 of the mounting ring 4, thus completing the precise positioning of the bearing.

[0052] It is known that the second bearing 62, as the main support point of the planetary carrier assembly, directly bears the radial force generated by the meshing of the planetary gears 7. For example, when the planetary gears 7 transmit torque, their radial force on the planetary carrier is evenly distributed to the gear ring 3 and the mounting ring 4 through the bearing, avoiding the deflection deformation of traditional cantilever support structures. The high-precision fit and rigid housing design of the second bearing 62 control the radial runout of the planetary carrier assembly at high speed within the micrometer level, ensuring uniform meshing clearance between the planetary gears 7 and the sun gear 1 and gear ring 3, reducing vibration and noise. In addition, the bearing mounting cavity utilizes the annular gap naturally formed after the assembly of the gear ring 3, mounting ring 4, first planetary carrier 51 and second planetary carrier 52, rather than creating an additional independent space in the axial direction. The thickness of the second bearing 62 is completely hidden within this bearing mounting cavity, without the need for additional bearing seats or axial extension, thus successfully maintaining the ultra-thin profile of the entire device while maintaining the same load-bearing capacity.

[0053] In this embodiment, as Figure 4 As shown, the opposite ends of the first planetary carrier 51 and the second planetary carrier 52 are connected and positioned through a mutually engaging stepped structure. Specifically, the end of the first planetary carrier 51 facing the second planetary carrier 52 is provided with a first step 511, and the end of the second planetary carrier 52 facing the first planetary carrier 51 is provided with a second step 522 that engages with the first step 511. The first step 511 and the second step 522 are engaged, that is, the protrusion of the first step 511 is embedded in the recess of the second step 522, and their mating surfaces abut against each other, so as to achieve radial positioning and connection between the first planetary carrier 51 and the second planetary carrier 52.

[0054] The plug-in step structure of the first step 511 and the second step 522 ensures that the first planetary carrier 51 and the second planetary carrier 52 have extremely high coaxiality after assembly. This ensures that all planetary gears 7 mesh correctly with the sun gear 1 and the internal gear ring 31, avoiding the premise of uneven load and noise.

[0055] In this embodiment, the side of the second step 522 facing the bearing mounting cavity abuts against the inner ring of the second bearing 62. During assembly, the second planetary carrier 52 moves towards the first planetary carrier 51 along with the inner ring of the second bearing 62. The movement stops when the end face of the second step 522 of the second planetary carrier 52 firmly abuts against the axially contacting side of the inner ring of the second bearing 62. At this point, the inner ring of the second bearing 62 is firmly clamped between the second step 522 of the second planetary carrier 52 and the first step 511 of the first planetary carrier 51, ensuring that the inner ring of the second bearing 62 will not move axially on the second planetary carrier 52, thus achieving axial fixation. Furthermore, the axial positioning function of the bearing is directly integrated into the main body structure (second step 522) of the second planetary carrier 52, eliminating the need for separate bearing positioning sleeves, locking nuts, or complex pressure caps. Reducing one part means saving space and assembly steps, thereby improving performance, compressing space, and achieving a compact structure.

[0056] In this embodiment, as Figure 1 As shown, the sun gear 1 is fitted with a transition sleeve 2, which is supported by a third bearing 63 on the side of the first planetary carrier 51 opposite to the second planetary carrier 52. Preferably, the inner wall of the transition sleeve 2 on the side away from the sun gear 1 is connected to the outer circle of the motor shaft, and the inner wall size can be set according to the size of the motor shaft; the shaft on the side of the sun gear 1 away from the second planetary carrier 52 is provided with axial stripes extending from the tooth roots to increase the radial engagement force when connected to the motor shaft.

[0057] The transition sleeve 2 is an annular connector fitted around the outer circumference of the sun gear 1. Its inner side mates with the sun gear 1, and its outer side mates with the third bearing 63. The diameters of these holes are adapted to the outer diameter of the sun gear 1 and the inner ring size of the third bearing 63, respectively, forming a force transmission chain from the sun gear 1 to the transition sleeve 2 and then to the third bearing 63. The inner ring of the third bearing 63 has an interference or transition fit with the outer circumference of the transition sleeve 2, and its outer ring mates with the bearing hole on the side of the first planetary carrier 51 opposite to the second planetary carrier 52 (i.e., the input end side of the first planetary carrier 51). Ultimately, this transmits the radial force at the input end of the sun gear 1 to the first planetary carrier 51. Furthermore, one end of the sun gear 1 is supported on the inner side of the second planetary carrier 52 by the first bearing 61, while the third bearing 63 forms a second support on the outer side of the first planetary carrier 51. Together, they constitute the radial support system at both ends of the sun gear 1, which restricts the radial displacement of the sun gear 1 and controls the radial deflection of the sun gear 1 to the micrometer level. This ensures that the axis of the sun gear 1 always coincides with the axis of the planetary carrier, thereby avoiding meshing off-center load caused by deflection from the root cause and reducing tooth surface wear and noise.

[0058] It is known that, as the core component of the reducer, if the sun gear 1 were directly machined to fit the motor shaft, different specifications of sun gear 1 would need to be designed for different motor shaft diameters, resulting in a large variety of parts and high costs. Specifically, the transition sleeve 2, with its dual-diameter design—internal for the sun gear 1 and external for the motor shaft—serves as an intermediate adapter. For example, when the motor shaft diameter is smaller than the inner diameter of the sun gear 1, connection can be achieved through an interference fit between the inner diameter of the transition sleeve 2 and the sun gear 1, and a transition fit between the outer diameter and the motor shaft. If the motor shaft diameter is different, only a transition sleeve 2 with a different diameter needs to be replaced, without redesigning the sun gear 1. This greatly improves the reducer's versatility, allowing for quick adaptation to motors of different power and shaft diameters, and reducing R&D and production cycles.

[0059] Furthermore, the third bearing 63 is installed on the side of the first planetary carrier 51 opposite to the second planetary carrier 52, while the transition sleeve 2 is an annular piece fitted around the outer circumference of the sun gear 1. The axial lengths of both are controlled within the thickness range of the input end side of the first planetary carrier 51, without adding extra length to the overall axial dimension of the reducer. This is equivalent to utilizing the unused space on the input end side to arrange the support structure. For example, if the input end side of the first planetary carrier 51 itself needs to reserve space for connection with the motor, the third bearing 63 and the transition sleeve 2 can be directly integrated into that space, ensuring that the overall thickness of the reducer is not affected.

[0060] Power is input from the sun gear 1, which is stably supported by the first bearing 61 and the third bearing 63. The third bearing 63, which serves as an auxiliary support for the input, is supported on the other side of the sun gear 1 through the transition sleeve 2, forming a stable two-point support together with the first bearing 61. This prevents the sun gear 1 from wobbling due to excessive cantilever length and ensures meshing accuracy. The sun gear 1 drives multiple planetary gears 7 evenly distributed around the sun gear 1. While meshing with the fixed internal gear ring 31, the planetary gears 7 revolve around the sun gear 1, thus causing the planetary shaft 8 to rotate. The rotational motion of the planet carrier is transmitted through the first planet carrier 51 and the second planet carrier 52 connected together. The first planet carrier 51 and the second planet carrier 52 are set separately. The first planet carrier 51 usually mainly supports the planetary gears 7. The second planet carrier 52 not only supports the planetary gears 7 together with the first planet carrier 51, but more importantly, it serves as the power output end. The second planet carrier 52 is designed to be partially embedded in the mounting ring 4 and overlaps axially with the end structure of the gear ring 3, which directly leads to a reduction in the overall thickness. The second planetary carrier 52, which serves as the direct output component, receives final support for its rotational motion from the second bearing 62 within the mounting ring 4, ensuring its stability at high speeds. In other words, through the robust frame of the gear ring 3-mounting ring 4, the precise positioning of the split planetary carrier assembly, and the multi-point bearing support for both input and output, stable and highly rigid rotational support is provided for the input and output shafts within an extremely compact space, guaranteeing transmission accuracy and lifespan.

[0061] In this embodiment, as Figure 6 As shown, the outer end face of the second planetary carrier 52 is provided with a flower-shaped groove 521, which can provide positioning when positioning is insufficient and also reduce the weight of the reducer.

[0062] In this embodiment, the outer end face of the second planetary carrier 52 has an axial threaded hole for fixing the corresponding working machine. The working machine and the outer end face of the mounting ring 4 cooperate to form a positioning stop, saving axial distance.

[0063] In this embodiment, as Figure 5 As shown, each planetary gear 7 is fitted onto a corresponding planetary shaft 8, with both ends of the planetary shaft 8 fixed to the first planetary carrier 51 and the second planetary carrier 52, respectively. The planetary gear 7 is mounted in the planetary gear 7 mounting cavity of the planetary carrier assembly via the planetary shaft 8, and revolves and rotates with the sun gear 1 and the internal gear ring 31, achieving speed reduction and torque amplification. The pin holes corresponding to the first planetary carrier 51 and the second planetary carrier 52 are each provided with small air holes. After the planetary shaft 8 is pressed in, the air in the pin holes can be smoothly discharged. Its structure is simple, but it effectively restricts the axial movement of the planetary shaft 8 and facilitates installation.

[0064] Preferably, a fan-shaped protrusion is provided between adjacent planetary gears 7 and fixed to the first planetary carrier 51 by axial screws 9; alternatively, the fan-shaped protrusion can be integrally formed with the first planetary carrier 51 to provide initial positioning and fixation of the planetary gears 7 and to constrain their surroundings. Gaskets are provided on both the upper and lower end faces of the planetary gears 7 to accommodate machining and assembly errors, ensure uniform axial force distribution, avoid uneven loading, and adapt to the compact axial space requirements of the ultra-thin reducer.

[0065] In this embodiment, the first bearing 61, the second bearing 62 and the third bearing 63 are all ultra-thin deep groove ball bearings, which simplify the structure and save space. This not only greatly reduces the axial dimension, but also reduces the radial space occupied.

[0066] The first bearing 61 supports the sun gear 1, which is installed in the mounting slot 523 of the second planetary carrier 52. Using an ultra-thin bearing means this slot can be made shallower, thus reducing the axial thickness of the second planetary carrier 52. The second bearing 62 supports the output planetary carrier, which is installed in the bearing mounting cavity formed by the gear ring 3 and the mounting ring 4. Using an ultra-thin bearing means this cavity can be made narrower, allowing for a thinner design for the extension 41 of the mounting ring 4 or the mounting slot 32 of the gear ring 3, directly compressing the overall length. The third bearing 63 supports the input transition sleeve 2, located at the front end of the first planetary carrier 51. Using an ultra-thin bearing directly reduces the overhang length of the reducer's input end.

[0067] In other words, these three bearings are simultaneously "slimmed down" at the three key support points of the reducer, thereby achieving a more compact layout in the radial direction, which enables the reducer to achieve a smaller external size or a better internal structure design in the radial direction.

[0068] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0069] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0070] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a 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 according to the specific circumstances.

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0072] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Since these modifications and variations fall within the scope of the claims and their equivalents, this application also intends to include these modifications and variations.

[0073] The above description describes specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An ultra-thin planetary gear reducer, characterized in that, include: Sun wheel (1); A gear ring (3) is coaxially sleeved on the outside of the sun gear (1), and the inner ring wall of the gear ring (3) is provided with an inner gear ring (31); The planetary carrier assembly includes a first planetary carrier (51) and a second planetary carrier (52) arranged opposite to each other along the thickness direction of the gear ring (3). The first planetary carrier (51) is arranged corresponding to the inner gear ring (31). The second planetary carrier (52) is connected to the first planetary carrier (51) and together with the first planetary carrier (51) and the gear ring (3) form a planetary gear (7) mounting cavity. Multiple planetary gears (7) are evenly distributed circumferentially in the mounting cavity of the planetary gears (7), and each planetary gear (7) meshes with the internal gear ring (31) and the sun gear (1) simultaneously; A mounting ring (4) is provided at the end of the gear ring (3), and at least a portion of the second planetary carrier (52) is accommodated in the inner hole of the mounting ring (4).

2. The ultra-thin planetary gear reducer according to claim 1, characterized in that, The sun gear (1) passes through the center of the first planetary carrier (51) and the second planetary carrier (52) in sequence. The second planetary carrier (52) has a mounting groove (523) on the side facing the first planetary carrier (51). The sun gear (1) is supported in the mounting groove (523) of the second planetary carrier (52) by a first bearing (61).

3. The ultra-thin planetary gear reducer according to claim 2, characterized in that, The gear ring (3) has an assembly groove (32) at one end near the second planetary carrier (52). The mounting ring (4) has a radially inward extension (41) on the side facing the second planetary carrier (52). The extension (41), the assembly groove (32), the outer circumference of the first planetary carrier (51) and the second planetary carrier (52) form an annular bearing mounting cavity. The bearing mounting cavity contains a second bearing (62).

4. The ultra-thin planetary gear reducer according to claim 3, characterized in that, The first planetary carrier (51) has a first step (511) at the end facing the second planetary carrier (52), and the second planetary carrier (52) has a second step (522) at the end facing the first planetary carrier (51) that matches the first step (511); wherein the first step (511) and the second step (522) engage to achieve radial positioning and connection between the first planetary carrier (51) and the second planetary carrier (52).

5. The ultra-thin planetary gear reducer according to claim 4, characterized in that, The side of the second step (522) facing the bearing mounting cavity abuts against the inner ring of the second bearing (62).

6. The ultra-thin planetary gear reducer according to claim 5, characterized in that, The sun gear (1) is fitted with a transition sleeve (2), which is supported by a third bearing (63) on the side of the first planetary carrier (51) away from the second planetary carrier (52).

7. The ultra-thin planetary gear reducer according to claim 1, characterized in that, The outer end face of the second planetary carrier (52) is provided with a flower-shaped groove (521) along the axis.

8. The ultra-thin planetary gear reducer according to claim 1, characterized in that, The outer end face of the second planetary carrier (52) has an axial threaded hole for fixing the corresponding working machine. The working machine and the outer end face of the mounting ring (4) cooperate to form a positioning stop.

9. The ultra-thin planetary gear reducer according to claim 1, characterized in that, Each of the planetary gears (7) is fitted onto a corresponding planetary shaft (8), the two ends of which are fixed to the first planetary carrier (51) and the second planetary carrier (52), respectively.

10. The ultra-thin planetary gear reducer according to claim 6, characterized in that, The first bearing (61), the second bearing (62) and the third bearing (63) are all ultra-thin deep groove ball bearings.

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