A differential precision bearing cycloidal reducer

Abstract

This invention relates to the field of speed reduction equipment technology, specifically to a differential precision bearing cycloidal reducer. The differential precision bearing cycloidal reducer includes an input shaft, a rear cover, a housing, an output end, and a drive gear. A cam structure is fixedly sleeved on the input shaft; the rear cover is sleeved on the input shaft and forms a rotational seal connection with it; the housing is sleeved on the input shaft and detachably connected to the rear cover, with multiple first pin teeth arranged on its inner peripheral wall; the output end is sleeved on the input shaft and forms a rotational seal connection with both the input shaft and the housing, and together with the input shaft, rear cover, and housing, forms a sealed chamber filled with lubricating oil; multiple second pin teeth are arranged on the inner peripheral wall of the output end; the drive gear is sleeved on the cam structure, located within the sealed chamber, and forms a rotational connection with the input shaft, simultaneously meshing with the first and second pin teeth. This design simplifies the structure while improving load capacity.

Description

Technical Field

[0001] This invention relates to the field of speed reduction equipment technology, and in particular to a differential precision bearing cycloidal speed reducer. Background Technology

[0002] In modern industrial systems, precision speed reducers play a crucial role as core transmission components of mechanical equipment. Like the "power transmission center" of a machine, they play a vital role in key areas such as the precise operation of industrial automated production lines, the efficient collaboration of intelligent manufacturing equipment, and the flexible operation of various robots. Their performance directly determines the accuracy of the equipment's movements during operation, its long-term stability, and its reliability in handling complex working conditions.

[0003] From a categorization perspective, common precision speed reducers mainly include worm gear reducers, planetary gear reducers, ordinary gear reducers, harmonic reducers, and bearing cycloidal reducers. Different types of precision speed reducers are based on their unique transmission principles and are suitable for different application scenarios. Among them, bearing cycloidal reducers, with their significant advantages in transmission efficiency, load-bearing capacity, and structural adaptability, have gained widespread application in many industrial fields, becoming the preferred transmission component for many devices with high requirements for transmission precision and stability.

[0004] The core principle of a bearing-driven cycloidal reducer is to achieve high reduction ratios and high-efficiency transmission through the cooperation of a cycloidal pinwheel and an eccentric bearing. Related technologies, such as Chinese patent application CN118564609A, disclose a high-load-bearing cycloidal reducer using all-needle roller bearings. This design, employing a high-load-bearing cycloidal reducer with all-needle roller bearings, utilizes an enlarged diameter eccentric wheel and cylindrical rollers combined with crossed roller bearings to solve the contradiction between size and rigidity in collaborative robot reducers, achieving higher load-bearing capacity and smaller space occupation.

[0005] However, existing cycloidal bearing reducers also have some problems in practical use: First, their transmission structure includes components such as cycloidal wheels, pinwheels, and eccentric bearings. Because of the need to reserve clearance and movement space, the structural design principle limits further reduction in size, making it difficult to meet the miniaturization requirements of equipment. Second, the transmission structure has many meshing and rotating parts, which are prone to elastic deformation under load. Third, the collaborative work of multiple components forms a complex dimensional chain. The longer the dimensional chain, the more factors affect transmission accuracy. The cumulative effect of dimensional deviations in each link amplifies the overall transmission accuracy. Finally, the use of various standard parts in manufacturing results in differences in manufacturing precision. During assembly, factors such as process, tools, and personnel skills can easily introduce assembly errors. The superposition of manufacturing and assembly errors makes it difficult to guarantee overall accuracy, affecting the operational accuracy of precision equipment and product quality. Summary of the Invention

[0006] Therefore, it is necessary to provide a differential precision bearing cycloidal reducer to address the problem of poor reliability in current bearing cycloidal reducers.

[0007] The above objectives are achieved through the following technical solutions:

[0008] A differential precision bearing cycloidal reducer, the differential precision bearing cycloidal reducer comprising:

[0009] An input shaft is capable of rotating around its own axis; a cam structure is fixedly sleeved on the input shaft.

[0010] The rear cover is fitted onto the input shaft and forms a rotatable seal connection with the input shaft;

[0011] The housing is fitted onto the input shaft and is detachably connected to the rear cover. A plurality of first needle teeth are fixedly provided on the inner peripheral wall of the housing.

[0012] The output end is sleeved on the input shaft and forms a rotational seal connection with the input shaft and the housing, and can rotate around its own axis; the output end, the input shaft, the rear cover, and the housing together form a sealed chamber, which is filled with lubricating oil; a plurality of second needle teeth are fixedly provided on the inner peripheral wall of the output end;

[0013] The drive gear is movably sleeved on the cam structure and located in the sealed cavity, and forms a rotatable connection with the input shaft. The drive gear meshes with the first needle tooth and the second needle tooth simultaneously.

[0014] Furthermore, multiple cylindrical rollers are provided between the input shaft and the rear cover, between the input shaft and the drive gear, and between the input shaft and the output end. The input shaft, the cylindrical rollers and the rear cover, the input shaft, the cylindrical rollers and the drive gear, and the input shaft, the cylindrical rollers and the output end all form cylindrical roller bearings. Multiple crossed rollers are provided between the output end and the housing. The output end, the crossed rollers and the housing form crossed roller bearings.

[0015] Furthermore, a dynamic balancing part is provided on the input shaft, and the dynamic balancing part is disposed opposite to the small end of the cam structure and configured to enable the input shaft to maintain dynamic balance.

[0016] Furthermore, the cam structure has a dynamic balancing channel, which is configured to keep the input shaft dynamically balanced.

[0017] Furthermore, the dynamic balancing main channel includes multiple first channels, which are arranged circumferentially and extend in a direction parallel to the axis of the input shaft; each of the first channels is connected to a second channel and a third channel at both ends, and the second channel and the third channel connected to the same first channel extend in the radial direction of the input shaft and are connected to the sealed chamber; the lengths of the second channel and the third channel are not equal.

[0018] Furthermore, a first filter structure is provided between the input shaft and the rear cover, the first filter structure being configured to filter lubricating oil moving through the second channel; a second filter structure is provided between the input shaft and the output end, the second filter structure being configured to filter lubricating oil moving through the third channel.

[0019] Furthermore, the input shaft has a hollow structure; a vent hole is provided on the circumferential sidewall of the input shaft, and the vent hole is connected to the interior of the input shaft.

[0020] Furthermore, a plurality of heat dissipation fins are fixedly provided on the inner peripheral wall of the input shaft, and the plurality of heat dissipation fins are arranged circumferentially.

[0021] Furthermore, the heat dissipation fins are strip-shaped and extend in a direction parallel to the input shaft axis.

[0022] Furthermore, the differential precision bearing cycloidal reducer also includes a cold air source, which is configured to allow gas with a preset temperature to be introduced into the input shaft through the vent hole; the gas with the preset temperature is configured to absorb the heat of the input shaft.

[0023] The beneficial effects of this invention are:

[0024] This invention relates to a differential precision bearing cycloidal reducer. By configuring the input shaft and rear cover, the input shaft and drive gear, and the input shaft and output end all as cylindrical roller bearings, and replacing the inner and outer rings of the cylindrical roller bearings with the aforementioned structure, and configuring the output end and housing as a crossed roller bearing, replacing the inner ring of the crossed roller bearing with the output end and the outer ring with the housing, this reduces the number of parts, shortens the dimensional chain length and assembly difficulty, improves assembly accuracy, reduces the weight and size of the reducer, and also increases load capacity. Simultaneously, by configuring the bearing raceway and pin teeth to be machined on the same datum surface, a high-precision standard of coaxiality within a preset range is achieved, eliminating assembly errors at the source. Furthermore, by optimizing the matching relationship between the bearing support stiffness and the pin tooth deformation, ensuring that the stiffness gradient difference is less than a preset percentage, it helps to improve the overall structural rigidity and stability.

[0025] Furthermore, by setting up a dynamic balancing unit and utilizing its weight and position characteristics, the center of gravity shift caused by the cam structure to the input shaft can be offset, thereby achieving dynamic balance of the input shaft and improving its stability during rotation.

[0026] Furthermore, by opening a first channel, a second channel, and a third channel in the small end of the cam structure, dynamic balance of the input shaft can be achieved, and compared with the existing cycloidal pinwheel structure, additional torque can be avoided. Furthermore, by setting the second and third channels to have different lengths, the lubricating oil in the sealed chamber can flow, which is beneficial to improving the lubrication effect on various components in the reducer.

[0027] Furthermore, by setting up a first filter structure and a second filter structure, the lubricating oil can be filtered, which helps to reduce the impact of impurities in the lubricating oil on the operation of various components in the reducer.

[0028] Furthermore, by setting the input shaft to a hollow structure and opening ventilation holes on the circumferential sidewall of the input shaft, the air inside the input shaft can be exchanged with the outside air through the ventilation holes when the input shaft rotates, thereby achieving heat dissipation of the input shaft. This not only helps to reduce the temperature of the components inside the reducer, but also helps to improve the operational stability of the components inside the reducer.

[0029] Furthermore, by adding heat dissipation fins, the contact area between the air and the input shaft is increased, thereby improving the heat dissipation efficiency of the input shaft.

[0030] Furthermore, by setting up a cold air source, the temperature of the gas introduced into the input shaft is kept low, thereby increasing the temperature difference between the gas and the input shaft and improving the heat dissipation efficiency of the input shaft. Attached Figure Description

[0031] Figure 1 A three-dimensional structural schematic diagram of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention;

[0032] Figure 2 A three-dimensional cross-sectional view of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention;

[0033] Figure 3 for Figure 2 A magnified schematic diagram of the structure at point Y in the middle;

[0034] Figure 4 for Figure 3 A magnified schematic diagram of the structure at point Z in the middle;

[0035] Figure 5 A three-dimensional structural diagram of the input shaft of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention. Figure 1 ;

[0036] Figure 6 A three-dimensional structural schematic diagram of the rear cover of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention;

[0037] Figure 7 A three-dimensional cross-sectional view of the housing of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention;

[0038] Figure 8 A three-dimensional cross-sectional view of the output end of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention;

[0039] Figure 9 A three-dimensional structural schematic diagram of the drive gear of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention;

[0040] Figure 10 A three-dimensional structural diagram of the input shaft of the differential precision bearing cycloidal reducer provided in an embodiment of the present invention. Figure 2 .

[0041] in:

[0042] 1. Input shaft; 101. Cam structure; 1011. First channel; 1012. Second channel; 1013. Third channel; 102. Vent hole; 103. Heat dissipation fins; 104. First ring platform; 105. Third ring platform; 106. Counterweight;

[0043] 2. Rear cover; 201. Second ring platform; 202. First flange; 2021. Sealing ring; 2022. Connecting hole;

[0044] 3. Housing; 301. First needle tooth; 302. Second flange; 303. Mounting hole; 304. Plug;

[0045] 4. Output end; 401. Second needle tooth; 402. Fourth ring platform;

[0046] 5. Sealed chamber;

[0047] 6. Drive gear;

[0048] 7. Cylindrical rollers;

[0049] 8. Cross rollers;

[0050] 9. First filter ring;

[0051] 10. Second filter ring;

[0052] 11. First sealing ring;

[0053] 12. Second sealing ring;

[0054] 13. The third annular space;

[0055] 14. Third sealing ring;

[0056] 15. Blocking rod. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0058] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage," unless otherwise specified, include both direct and indirect connections (linkages). In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description. They 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 limiting the invention.

[0059] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0060] Existing bearing cycloidal reducers still have some problems that need to be solved in practical industrial applications: First, in terms of size, since their transmission structure needs to include multiple key components such as cycloidal wheel, pin wheel, and eccentric bearing, and a certain amount of fitting clearance and movement space needs to be reserved between each component, the overall size is difficult to be further reduced significantly from the structural design principle. This creates certain limitations in application scenarios where there are high requirements for equipment miniaturization.

[0061] Secondly, regarding stiffness and strength, the transmission structure of the bearing cycloidal reducer contains numerous meshing parts and rotating components. These parts are prone to elastic deformation under heavy loads. From a mechanical perspective, the series transmission of multiple components means that the overall structural stiffness is affected by the combined stiffness of each component. Insufficient stiffness in any one component can lead to a decrease in overall stiffness. Simultaneously, long-term load application and alternating stress make these critical components susceptible to fatigue damage, affecting the overall structural strength and consequently reducing the reducer's service life and operational stability.

[0062] Furthermore, regarding the dimensional chain, the transmission process of a bearing cycloidal reducer involves the coordinated work of multiple components. The dimensional accuracy and installation position accuracy of each component together constitute a complex dimensional chain. Analyzing the principle of the dimensional chain, the longer the dimensional chain, the more factors affect the final transmission accuracy. Dimensional deviations in any link can be amplified through the cumulative effect of the dimensional chain, leading to a decrease in overall transmission accuracy.

[0063] Finally, regarding accuracy assurance, the manufacturing process of existing bearing cycloidal reducers requires the use of various standard parts, and the manufacturing precision of these different standard parts varies. Furthermore, during assembly, assembly errors are unavoidable due to factors such as assembly techniques, tools, and operator skill levels. These manufacturing and assembly errors, combined with each other, fundamentally make it difficult to effectively guarantee the overall precision of the reducer. In precision equipment applications with extremely high transmission accuracy requirements, this may affect the equipment's operational accuracy and product quality.

[0064] Based on this, embodiments of the present invention provide a differential precision bearing cycloidal reducer, which is particularly suitable for industrial automation, intelligent manufacturing, robotics and other fields.

[0065] Specifically, refer to Figures 1 to 10 As shown, in the differential precision bearing cycloidal reducer provided in this embodiment of the invention, it is configured to include an input shaft 1, which is rotatable about its own axis and is configured to receive power input into the differential precision bearing cycloidal reducer. A cam structure 101 is fixedly sleeved on the input shaft 1. The cam structure 101 has a large end and a small end, and the large end of the cam structure 101 is coaxially arranged with the input shaft 1. A rear cover 2 is also sleeved on the input shaft 1. The rear cover 2 is an annular structure and is coaxial with and spaced apart from the input shaft 1. A first annular platform 104 is fixedly sleeved on the input shaft 1 and is located above the cam structure 101. A second annular platform 201 is coaxially and fixedly arranged on the inner peripheral wall of the rear cover 2 and is located above the first annular platform 104.

[0066] The first annular platform 104, the second annular platform 201, the input shaft 1, and the rear cover 2 together form a first annular space. Multiple cylindrical rollers 7 are inserted into this first annular space. These cylindrical rollers 7 are evenly arranged circumferentially and are parallel to the input shaft 1. The two ends of each cylindrical roller 7 are respectively held by the first annular platform 104 and the second annular platform 201 to prevent axial runout. The peripheral walls of the cylindrical rollers 7 simultaneously form rolling friction contact with the outer peripheral wall of the input shaft 1 and the inner peripheral wall of the rear cover 2, allowing the cylindrical rollers 7 to rotate both around their own axis and around the axis of the input shaft 1. The rotation of the rollers causes the input shaft 1, cylindrical rollers 7, and rear cover 2 to form a cylindrical roller bearing, with the inner ring of the cylindrical roller bearing replaced by the input shaft 1 and the outer ring replaced by the rear cover 2. A first sealing ring 11 is also fitted onto the input shaft 1, which is located on the inner side of the rear cover 2 and forms circumferential surface contact with the inner circumferential wall of the rear cover 2. It is placed on the top of the second ring platform 201, thereby sealing the input shaft 1, the second ring platform 201, and the rear cover 2. Under the combined action of the cylindrical rollers 7 and the first sealing ring 11, the input shaft 1 and the rear cover 2 form a rotationally sealed connection.

[0067] A first flange 202 is coaxially and fixedly fitted onto the rear cover 2. A sealing ring 2021 is coaxially and fixedly installed on the bottom outer edge of the first flange 202. A housing 3 is also fitted onto the input shaft 1. The housing 3 is annular in structure and is coaxial with and spaced apart from the input shaft 1. The housing 3 is located below the rear cover 2, and its top end is located inside the sealing ring 2021. The top end face of the housing 3 abuts against the bottom of the first flange 202, forming a circumferential surface contact. It is detachably connected by bolts. The outer peripheral wall of the housing 3 near the top abuts against the inner peripheral wall of the sealing ring 2021, forming a circumferential surface contact to ensure sealing. A second flange 302 is fixedly fitted onto the housing 3 near the middle. The second flange 302 is used to connect to the external structure by bolts to fix the position of the reducer.

[0068] An output end 4 is sleeved on the input shaft 1. The output end 4 is an annular structure, coaxial with the input shaft 1 and spaced apart. The output end 4 is located below the rear cover 2 and inside the housing 3, and can rotate around its own axis. The output end 4 is configured to output decelerated power outward. A third annular platform 105 is also fixedly sleeved on the input shaft 1. The third annular platform 105 is located below the cam structure 101. A fourth annular platform 402 is coaxially and fixedly installed on the inner circumferential wall of the output end 4. The fourth annular platform 402 is located below the third annular platform 105. The third annular platform 105, the fourth annular platform 402, the input shaft 1 and the output end 4 together form a second annular space. Multiple cylindrical rollers 7 are inserted in the second annular space. The multiple cylindrical rollers 7 are evenly arranged circumferentially and are all parallel to the input shaft 1. The two ends of the cylindrical rollers 7 are respectively connected by the third annular platform. The cylindrical roller 7 is clamped by the fourth ring platform 402 to prevent axial runout. The peripheral wall of the cylindrical roller 7 simultaneously forms rolling friction contact with the outer peripheral wall of the input shaft 1 and the inner peripheral wall of the output end 4, so that the cylindrical roller 7 can rotate both around its own axis and around the axis of the input shaft 1. Thus, the input shaft 1, the cylindrical roller 7 and the output end 4 together form a cylindrical roller bearing, and the inner ring of the cylindrical roller bearing is replaced by the input shaft 1 and the outer ring is replaced by the output end 4. A second sealing ring 12 is also sleeved on the input shaft 1. The second sealing ring 12 is located inside the output end 4 and forms circumferential surface contact with the inner peripheral wall of the output end 4. It is placed at the bottom of the fourth ring platform 402, thereby sealing the input shaft 1, the fourth ring platform 402 and the output end 4. Under the combined action of the cylindrical roller 7 and the second sealing ring 12, the input shaft 1 and the output end 4 form a rotational sealing connection.

[0069] A third annular space 13 is formed between the outer peripheral wall of the output end 4 and the inner peripheral wall of the housing 3. The third annular space 13 has a conical annular structure with the smaller opening at the top. The upper half of the third annular space 13 is embedded in the outer peripheral wall of the output end 4, and the lower half is embedded in the inner peripheral wall of the housing 3. Multiple crossed rollers 8 are inserted into the third annular space 13. The multiple crossed rollers 8 are evenly arranged circumferentially, and adjacent crossed rollers 8 are crossed and separated by a partition seat. The partition seat wraps around part of the circumferential sidewall of the crossed rollers 8. In this bearing, the inclination direction of one of the adjacent crossed rollers 8 is the same as the inclination direction of the third annular space 13. This crossed roller 8 simultaneously forms rolling friction contact with the outer peripheral wall of the output end 4 and the inner peripheral wall of the housing 3, allowing it to rotate both around its own axis and around the axis of the input shaft 1. This allows the input shaft 1, the crossed roller 8, the separator, and the output end 4 to collectively form a crossed roller bearing, with the output end 4 replacing the inner ring of the crossed roller bearing and the housing 3 replacing the outer ring. A third sealing ring 14 is fitted onto the output end 4, located inside the housing 3 and below the crossed roller 8, thereby sealing the housing 3 and the output end 4. Under the combined action of the first sealing ring 11, the second sealing ring 12 and the third sealing ring 14, the input shaft 1, the rear cover 2, the housing 3 and the output end 4 together form a sealed chamber 5, and the sealed chamber 5 is filled with lubricating oil. The lubricating oil is used to lubricate all moving parts in the sealed chamber 5, such as the input shaft 1, the output end 4, the cylindrical rollers 7 and the crossed rollers 8.

[0070] It should be noted that, in order to facilitate the installation of the cross rollers 8 and the spacer, a mounting hole 303 is provided through the circumferential side wall of the housing 3, and a plug 304 is sealed at the mounting hole 303. During installation, the plug 304 is first removed, and then the cross rollers 8 and the spacer are inserted into the third annular space 13 through the mounting hole 303. Then the plug 304 is sealed at the mounting hole 303 to prevent lubricating oil from leaking from the mounting hole 303.

[0071] A drive gear 6 is movably inserted into the sealed chamber 5. The drive gear 6 is located between the rear cover 2 and the output end 4 in the vertical direction, and between the input shaft 1 and the housing 3 in the inward and outward direction. It is coaxial with the input shaft 1 and spaced apart. The drive gear 6 is also sleeved on the cam structure 101, and its upper end face forms a circumferential surface contact with the bottom of the first flange 202, and its lower end face forms a circumferential surface contact with the top of the output end 4. A plurality of cylindrical rollers 7 are inserted between the drive gear 6 and the cam structure 101. The plurality of cylindrical rollers 7 are arranged along the outer edge of the cam structure 101. The cylindrical rollers 7 are evenly arranged and parallel to the input shaft 1. The two ends of the cylindrical rollers 7 are respectively held by the first ring platform 104 and the third ring platform 105 to prevent axial runout. The peripheral sidewalls of the cylindrical rollers 7 simultaneously form rolling friction contact with the outer peripheral wall of the cam structure 101 and the inner peripheral wall of the drive gear 6, so that the cylindrical rollers 7 can rotate both around their own axis and around the axis of the input shaft 1. Thus, the input shaft 1, the cylindrical rollers 7 and the drive gear 6 together form a cylindrical roller bearing, and the inner ring of the cylindrical roller bearing is replaced by the input shaft 1 and the outer ring is replaced by the drive gear 6.

[0072] Multiple first needle teeth 301 are fixedly arranged on the inner peripheral wall of the housing 3 near the top. The first needle teeth 301 are columnar structures and are arranged parallel to the housing 3. The multiple first needle teeth 301 are evenly distributed circumferentially and are partially embedded in the inner peripheral wall of the housing 3. Multiple second needle teeth 401 are fixedly arranged on the inner peripheral wall of the output end 4 near the top. The second needle teeth 401 are columnar structures and are arranged parallel to the output end 4. The multiple second needle teeth 401 are evenly distributed circumferentially and are partially embedded in the inner peripheral wall of the output end 4. The second needle teeth 401 are arranged further inward and lower than the first needle teeth 301. The drive gear 6 meshes with both the first needle teeth 301 and the second needle teeth 401.

[0073] During operation, power is input to the input shaft 1, causing it to rotate around its own axis. As the input shaft 1 rotates, it simultaneously drives the cylindrical roller 7 between the input shaft 1 and the rear cover 2 to rotate around its own axis, and this cylindrical roller 7 rotates synchronously around the axis of the input shaft 1. Simultaneously, it also drives the cam structure 101 to rotate. When the cam structure 101 rotates, it simultaneously drives the cylindrical roller 7 between the cam structure 101 and the drive gear 6 to rotate around its own axis, and this cylindrical roller 7 rotates synchronously around the axis of the input shaft 1. Simultaneously, it also drives the drive gear 6 to rotate around its own axis, and simultaneously drives the drive gear 6 to rotate around the axis of the input shaft 1. When the drive gear 6 rotates, it simultaneously drives the output end 4 to rotate around its own axis through meshing with the first needle tooth 301 and the second needle tooth 401, and the output end 4 synchronously outputs the decelerated power outwards. When the output end 4 rotates, it drives the cylindrical roller 7 between the output end 4 and the input shaft 1 to rotate around its own axis. The cylindrical roller 7 rotates synchronously around the axis of the input shaft 1. On the other hand, it drives the cross roller 8 of the adjacent cross rollers 8, whose inclination direction is the same as that of the third annular space 13, to rotate around its own axis. The cross roller 8 rotates synchronously around the axis of the input shaft 1. The other cross roller 8 rotates synchronously around the axis of the input shaft 1. The separator seat rotates synchronously around the axis of the input shaft 1.

[0074] Therefore, at the mating points between the input shaft 1 and the rear cover 2, the input shaft 1 and the drive gear 6, and the input shaft 1 and the output end 4, no additional inner and outer rings of cylindrical roller bearings are provided. Instead, the input shaft 1 is directly used as a replacement structure for the inner ring of the cylindrical roller bearing, and the rear cover 2, the drive gear 6, and the output end 4 are respectively used as replacement structures for the outer rings of the cylindrical roller bearings at the corresponding positions. By embedding cylindrical rollers 7 in each mating clearance, the transmission components simultaneously undertake the support function of the cylindrical roller bearings. This reduces the number of cylindrical roller bearings and shortens the dimensional chain length—the support and transmission functions that originally required multiple sets of cylindrical roller bearings and transmission components to achieve are now accomplished through a single mating structure. This avoids the accumulation of errors during the assembly of multiple components and reduces the reserved clearances and installation space between parts, thereby reducing the overall weight and shrinking the external dimensions.

[0075] At the mating point between the output end 4 and the housing 3, the traditional independent crossed roller bearing design is also abandoned. Instead, the output end 4 serves as the inner ring of the crossed roller bearing, and the housing 3 serves as the outer ring. The crossed roller 8 and the spacer are directly embedded in the conical annular gap formed by the two. This structure not only retains the advantages of crossed roller bearings in terms of load-bearing capacity, but also reduces the installation steps of the crossed roller bearings through component replacement. This allows the transmission of the output end 4 and the fixed support of the housing 3 to work closely together, further optimizing the spatial layout and improving the overall structural compactness.

[0076] Simultaneously, during the machining of the housing 3 and the output end 4, the inner circumferential raceway (for mounting the crossed rollers 8) of the housing 3 and the mounting groove of the first needle tooth 301, and the outer circumferential raceway (for mounting the crossed rollers 8) of the output end 4 and the mounting groove of the second needle tooth 401 are machined synchronously on the same reference surface. This machining method ensures the high consistency of the bearing raceway and the needle tooth in geometric position, making their axes completely coincide, thus avoiding coaxiality errors caused by reference differences from the source.

[0077] Furthermore, when a load is applied to the output end 4 and the drive gear 6, the bearing's supporting deformation and the needle tooth's meshing deformation can compensate for each other, avoiding local stress concentration. For example, when the drive gear 6 is subjected to force while meshing with the needle tooth, the slight deformation of the needle tooth can be buffered by the appropriate deformation of the bearing. Conversely, the bearing's supporting deformation can also be balanced by adjusting the rigidity of the needle tooth, thereby reducing structural damage caused by excessive local deformation and significantly improving the overall structural rigidity and operational stability.

[0078] In a further embodiment, the presence of the cam structure 101 causes the center of gravity of the input shaft 1 and the cam structure 101 as a whole to be biased towards the small end of the cam structure 101, affecting the dynamic balance of the input shaft 1 when it rotates.

[0079] Based on this, in the differential precision bearing cycloidal reducer provided in this embodiment of the invention, a dynamic balancing part is further provided on the input shaft 1. The dynamic balancing part can be a counterweight 106, which has an arc-shaped structure and is positioned opposite to the small end of the cam structure 101, and is coaxial with the input shaft 1. In this way, the center of gravity of the input shaft 1, the cam structure 101, and the counterweight 106 as a whole coincides with the axis of the input shaft 1, thereby achieving dynamic balance of the input shaft 1 and improving the stability of the input shaft 1 during rotation.

[0080] In other embodiments, to achieve dynamic balance of the input shaft 1, a dynamic balance channel can be provided in the cam structure 101. The dynamic balance channel can be a single cavity structure or a combination of multiple cavity structures, thereby adjusting the overall mass distribution of the input shaft 1 and the cam structure 101, so that the center of gravity of the two as a whole coincides with the axis of the input shaft 1, fundamentally eliminating the unbalanced centrifugal force caused by the offset of the center of gravity, thereby achieving dynamic balance of the input shaft 1 and improving the stability of the input shaft 1 during rotation.

[0081] Meanwhile, in traditional cycloidal pinwheel structures, to achieve dynamic balance of input shaft 1, two eccentric components are typically used, such as an eccentric sleeve / bearing scheme: both eccentric sleeves / bearings are fixedly fitted onto input shaft 1, and both are eccentric relative to input shaft 1, with the eccentric ends facing each other, so that the center of gravity of input shaft 1 and the two eccentric sleeves / bearings as a whole coincides with the axis of input shaft 1, thus achieving dynamic balance of input shaft 1. However, because the two eccentric sleeves / bearings need to be arranged along the axial direction of input shaft 1, this structure will cause a new stability problem during the rotation of input shaft 1—although the centrifugal forces generated by the two eccentric sleeves / bearings are in opposite directions, due to the axial spacing, they form a pair of opposing and non-collinear forces. According to the principles of mechanics, this non-collinear opposing force will generate an additional torque (i.e., couple moment) on input shaft 1. This additional torque will cause the input shaft 1 to generate periodic torsional vibrations during rotation, which will disrupt the smoothness of the input shaft 1's rotation. Especially when rotating at high speed or under load, this vibration will be further amplified, which may cause fluctuations in the fit clearance between the input shaft 1 and surrounding components, or even cause abnormal wear between components, affecting the overall transmission accuracy and service life.

[0082] Compared to the traditional structure mentioned above, the dynamic balancing channel does not have the axially arranged double eccentric components found in the traditional structure. Therefore, it does not generate additional torque due to non-collinear reverse centrifugal force, and thus does not need to bear the additional load caused by the additional torque. This can effectively improve the smoothness and reliability of the input shaft 1 during rotation, thereby ensuring the accuracy and lifespan of the overall transmission system.

[0083] In a further embodiment, the dynamic balancing main channel is configured to include multiple first channels 1011, which are arranged at equal intervals along the circumference of the input shaft 1 and extend in a direction parallel to the axis of the input shaft 1, forming an arc-shaped structure. Each first channel 1011 extends upward to the first annular platform 104 and downward through the lower end face of the input shaft 1. A plug rod 15 is sealed at the bottom of each first channel 1011. The plug rod 15 facilitates the addition of lubricating oil from the first channel 1011 into the sealed chamber 5, and also facilitates the removal of the seal after the sealed chamber 5 is filled with lubricating oil. The sealed chamber 5 is isolated from the outside to prevent the lubricating oil in the sealed chamber 5 from leaking from the bottom of the first channel 1011; the upper end of each first channel 1011 is connected to a second channel 1012, which extends radially along the input shaft 1 and passes outward through the first annular platform 104 and communicates with the sealed chamber 5; the lower end of each first channel 1011 is connected to a third channel 1013, which extends radially along the input shaft 1 and passes outward through the third annular platform 105 and communicates with the sealed chamber 5; the length of the second channel 1012 is greater than the length of the third channel 1013.

[0084] During the rotation of the input shaft 1, the lubricating oil in the second channel 1012 and the third channel 1013 both have the same angular velocity as the input shaft 1. Under the influence of centrifugal force, the lubricating oil in the second channel 1012 and the third channel 1013 both have an outward flow and a tendency to flow into the sealed chamber 5. Since the length of the second channel 1012 is greater than the length of the third channel 1013, the linear velocity of the lubricating oil flowing out from the outer end of the second channel 1012 is greater than that of the lubricating oil flowing out from the outer end of the third channel 1013, and it has greater kinetic energy. Therefore, it can force the lubricating oil to form a circulating flow path of the second channel 1012, the sealed chamber 5, the third channel 1013, the first channel 1011, and the second channel 1012, thereby improving the lubrication effect on the various components in the reducer.

[0085] Understandably, in order to improve the flow efficiency of lubricating oil on both sides of the drive gear 6, multiple connecting holes 2022 are provided on the bottom side wall of the first flange 202. The multiple connecting holes 2022 are arranged circumferentially and connect the inner and outer sides of the drive gear 6, so that the lubricating oil forms a circulation path of the second channel 1012, the sealing chamber 5, the connecting hole 2022, the third channel 1013, the first channel 1011, and the second channel 1012.

[0086] It should be noted that, in order to ensure the dynamic balance of the input shaft 1, before the lubricating oil is filled into the sealed chamber 5, the cam structure 101 with the dynamic balance channel cannot keep the input shaft 1 dynamically balanced. At this time, the overall center of gravity of the cam structure 101 and the input shaft 1 is still deviated from the axis of the input shaft 1. After the lubricating oil fills the sealed chamber 5, the overall center of gravity of the cam structure 101, the lubricating oil in the dynamic balance channel and the input shaft 1 can coincide with the axis of the input shaft 1, thereby achieving the dynamic balance of the input shaft 1.

[0087] It should also be noted that since the main dynamic balancing channel is located on the small end side of the cam structure 101, and the small end of the cam structure 101 is the main position for driving the drive gear 6 to mesh with the first pinion 301 and the second pinion 401, the lubricating oil can be timely lubricated at the meshing position between the drive gear 6 and the first pinion 301 and the second pinion 401. This effectively reduces the dry friction when the drive gear 6 meshes with the first pinion 301 and the second pinion 401, reduces the wear on the tooth surface, extends the service life of the components, and avoids the problems of meshing noise and transmission efficiency reduction caused by insufficient lubrication.

[0088] In a further embodiment, to improve the lubrication effect on the components inside the reducer, a first filter structure is provided between the input shaft 1 and the rear cover 2. The first filter structure can be a first filter ring 9, which is coaxially and fixedly inserted into the inner peripheral wall of the first flange 202 and located below the second channel 1012. Multiple first filter holes are provided on the end face of the first filter ring 9. The first filter holes are used to filter the lubricating oil flowing from the second channel 1012 into the sealed chamber 5, thereby reducing the impact of impurities in the lubricating oil on the operation of the components inside the reducer. The inner edge of the first filter ring 9 is spaced apart from the cam structure 101 to avoid rotational wear. A second filter structure is provided between the output end 4 and the output end 4. The second filter structure can be a second filter ring 10. The second filter ring 10 has a ring-conical structure with the small opening at the top. The upper end of the second filter ring 10 is sleeved on the outer periphery of the third ring platform 105 and located above the third channel 1013. The lower end of the second filter ring 10 is coaxial and fixedly inserted into the top of the output end 4. Multiple second filter holes are provided on the conical sidewall of the second filter ring 10. The second filter holes are used to filter the lubricating oil flowing from the sealed chamber 5 into the third channel 1013, thereby reducing the impact of impurities in the lubricating oil on the operation of various components in the reducer. The inner edge of the second filter ring 10 and the third ring platform 105 are spaced apart to avoid rotational wear.

[0089] In other embodiments, to improve heat dissipation for the components within the reducer, the input shaft 1 is configured as a hollow structure. A vent 102 is provided on the circumferential sidewall near the top of the input shaft 1, and the vent 102 communicates with the interior of the input shaft 1. Thus, when the input shaft 1 rotates, the air inside the input shaft 1 can exchange with the outside air through the vent 102, thereby achieving heat dissipation for the input shaft 1. This not only helps to reduce the temperature of the components within the reducer but also improves the operational stability of the components within the reducer.

[0090] It is understandable that, in order to improve the exchange efficiency between the air inside the input shaft 1 and the ambient air, and thus improve the heat dissipation efficiency of the input shaft 1, the number of vent holes 102 can be set to multiple and arranged circumferentially.

[0091] In a further embodiment, to further improve the heat dissipation effect on the components inside the reducer, a plurality of heat dissipation fins 103 can be fixedly provided on the inner peripheral wall of the input shaft 1, and the plurality of heat dissipation fins 103 are arranged circumferentially. In this way, the presence of heat dissipation fins 103 can increase the contact area between air and input shaft 1, thereby improving the heat dissipation efficiency of input shaft 1, and further improving the heat dissipation effect on the components inside the reducer.

[0092] It is understandable that the heat dissipation fins 103 can be configured as strip structures and extend in a direction parallel to the axis of the input shaft 1.

[0093] In other embodiments, to further improve the heat dissipation effect of various components inside the reducer, the differential precision bearing cycloidal reducer may also include a cold air source, which may be an air conditioner, a refrigeration unit, etc. It can introduce gas with a preset temperature into the input shaft 1 through the vent 102, thereby making the temperature of the gas introduced into the input shaft 1 lower, and thus making the temperature difference between the gas and the input shaft 1 larger, thereby improving the heat dissipation efficiency of the input shaft 1, and further improving the heat dissipation effect of various components inside the reducer.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A differential precision bearing cycloidal reducer, characterized in that, The differential precision bearing cycloidal reducer includes: An input shaft is capable of rotating around its own axis; a cam structure is fixedly sleeved on the input shaft. The rear cover is fitted onto the input shaft and forms a rotatable seal connection with the input shaft; The housing is fitted onto the input shaft and is detachably connected to the rear cover. A plurality of first needle teeth are fixedly provided on the inner peripheral wall of the housing. The output end is sleeved on the input shaft and forms a rotational seal connection with the input shaft and the housing, and can rotate around its own axis; the output end, the input shaft, the rear cover, and the housing together form a sealed chamber, which is filled with lubricating oil; a plurality of second needle teeth are fixedly provided on the inner peripheral wall of the output end; The drive gear is movably sleeved on the cam structure and located in the sealed cavity, and forms a rotatable connection with the input shaft. The drive gear meshes with the first needle tooth and the second needle tooth simultaneously. Multiple cylindrical rollers are provided between the input shaft and the rear cover, between the input shaft and the drive gear, and between the input shaft and the output end. The input shaft, the cylindrical rollers, and the rear cover; the input shaft, the cylindrical rollers, and the drive gear; and the input shaft, the cylindrical rollers, and the output end all form cylindrical roller bearings. Multiple crossed rollers are provided between the output end and the housing. The output end, the crossed rollers, and the housing all form crossed roller bearings. The cam structure has a dynamic balancing channel, which is configured to keep the input shaft dynamically balanced. The dynamic balancing main channel includes multiple first channels, which are arranged circumferentially and extend in a direction parallel to the axis of the input shaft. Each first channel is connected to a second channel and a third channel at both ends. The second channel and the third channel connected to the same first channel extend in the radial direction of the input shaft and are connected to the sealed chamber. The lengths of the second channel and the third channel are not equal.

2. The differential precision bearing cycloidal reducer according to claim 1, characterized in that, The input shaft is provided with a dynamic balancing part, which is disposed opposite to the small end of the cam structure and configured to keep the input shaft dynamically balanced.

3. The differential precision bearing cycloidal reducer according to claim 1, characterized in that, A first filter structure is provided between the input shaft and the rear cover, the first filter structure being configured to filter lubricating oil moving through the second channel; a second filter structure is provided between the input shaft and the output end, the second filter structure being configured to filter lubricating oil moving through the third channel.

4. The differential precision bearing cycloidal reducer according to claim 1, characterized in that, The input shaft has a hollow structure; a vent hole is provided on the circumferential side wall of the input shaft, and the vent hole is connected to the interior of the input shaft.

5. The differential precision bearing cycloidal reducer according to claim 4, characterized in that, Multiple heat dissipation fins are fixedly arranged on the inner peripheral wall of the input shaft, and the multiple heat dissipation fins are arranged circumferentially.

6. The differential precision bearing cycloidal reducer according to claim 5, characterized in that, The heat dissipation fins are strip-shaped and extend in a direction parallel to the axis of the input shaft.

7. The differential precision bearing cycloidal reducer according to claim 4, characterized in that, The differential precision bearing cycloidal reducer also includes a cold air source, which is configured to allow gas with a preset temperature to be introduced into the input shaft through the vent hole; the gas with the preset temperature is configured to absorb the heat of the input shaft.

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