Double-layer roller rolling oscillating tooth speed reducer with double-row homodromous eccentric shock wave device

Abstract

The invention relates to the field of mechanical transmission, in particular to a double-layer roller rolling oscillating tooth speed reducer with a double-row homodromous eccentric shock wave device. According to the reducer, a triple uniform load mechanism is achieved through a set of systematized structure, first uniform load is achieved through the structural layout of the double-row homodromous eccentric shock wave device and the middle main supporting bearing, periodic overturning torque caused by a traditional reverse eccentric structure is fundamentally eliminated, and loads of transmission chains on the two sides are balanced. Second and third uniform loads are realized by a mandrel with radial elastic deformation, a roller with a convexity profile and a mandrel of the roller. Wherein the oscillating tooth assembly is constructed to be capable of compensating uneven circumferential load through elastic deformation of the mandrel, and meanwhile, the contact pressure of rollers at the two ends is uniform when the mandrel is bent due to the convexity design of the rollers or the mandrel. According to the structure, through the synergistic effect of multiple uniform loads, the requirement for the machining precision of parts is remarkably reduced, high bearing and high efficiency are kept, meanwhile, the operation stability is improved, and the manufacturing cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of mechanical transmission technology, and in particular to a double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator. Background Technology

[0002] High-precision, high-rigidity, and high-load-bearing capacity reducers are core components of industrial robots and high-end equipment. Currently, RV reducers and cycloidal pinwheel reducers dominate the field of heavy-load robot joints. However, these reducers have some inherent technical challenges: First, their transmission principle makes it difficult to reduce the pressure angle between the cycloidal wheel and the pin tooth, resulting in a large load on the eccentric shaft bearing, easy damage, and sliding friction between the pin tooth and the pin tooth housing, causing wear and thus limiting the reducer's precision and lifespan. Second, to achieve dynamic balance and symmetrical force transmission, traditional RV reducers and cycloidal pinwheel reducers use two eccentric shafts with a 180° phase difference to drive two cycloidal wheels (or cycloidal gears) respectively. However, in operation, due to minor manufacturing errors, it is difficult to ensure that the two cycloidal wheels are completely evenly loaded, which periodically generates a tilting torque on the support bearing, causing vibration and end jump, which is detrimental to improving the robot's motion accuracy and overall stability. Meanwhile, in order to cope with the overturning torque and ensure uniform load distribution, these reducers impose extremely stringent requirements on the machining accuracy of components (such as eccentricity consistency and cycloidal gear tooth profile accuracy), resulting in high manufacturing costs.

[0003] In pursuit of higher transmission efficiency and longer service life, rolling gear reducers were proposed and developed. These reducers theoretically significantly reduce friction losses by transforming the sliding contact between the live teeth and the shock wave generator, live gear carrier, and internal gear ring into rolling contact. However, most existing rolling gear reducer designs still utilize the traditional RV reducer's double-eccentric structure with a 180° phase difference to maintain inertial force balance. This design also introduces problems such as disruptive torque and uneven load distribution between the two transmission chains, and it remains insufficient to meet the combined requirements of high load capacity, low manufacturing cost, and high operational stability when facing harsh application environments. Summary of the Invention

[0004] The purpose of this invention is to provide a double-layer rolling gear reducer with a double-row co-directional eccentric shock wave generator. Through structural innovation, it fundamentally eliminates the overturning torque, achieves multi-stage load sharing, and significantly reduces the requirements for component machining accuracy while maintaining high load capacity and high efficiency. This achieves the goals of improving stability, extending service life, and reducing manufacturing costs. In turn, it solves the problems of overturning torque, uneven load distribution between the two rows, and high requirements for machining accuracy and cost in existing rolling gear reducers due to the use of a reverse eccentric structure.

[0005] The technical solution of the present invention is: a double-layer roller rolling tooth reducer with a double-row co-directional eccentric shock wave generator, comprising: an eccentric shaft assembly, a tooth frame assembly, an internal gear ring assembly, and at least one ring of tooth assembly; The eccentric shaft assembly includes an eccentric shaft on which two rows of shock generators are eccentrically aligned in the same direction; a main support bearing is disposed on the eccentric shaft and located in the middle of the two rows of eccentric shock generators, for supporting the eccentric shaft and balancing the load of the two rows of shock generators to achieve the first level of load equalization. The movable tooth assembly is arranged circumferentially within the radial mounting structure of the movable tooth frame assembly; the movable tooth assembly is constructed as a spindle structure with elastic deformation capability to compensate for the uneven load between the movable tooth assemblies and achieve a second load equalization. Furthermore, at least one row of rollers and / or its supporting spindle in the live tooth assembly that contacts the shock generator and the internal gear ring are configured to have a predetermined convex profile, so that when the spindle is subjected to bending deformation, the contact pressure of the rollers at both ends of the live tooth assembly is evenly distributed, thereby achieving a third layer of load equalization.

[0006] Preferably, the movable tooth assembly includes: movable toothed ring; The upper and lower mandrels are supported by the aforementioned toothed collar; Rollers installed on the upper and lower mandrels; The upper mandrel and the lower mandrel constitute the mandrel structure.

[0007] Preferably, the upper mandrel and / or the lower mandrel have a preset elastic deformation amount, enabling them to generate elastic bending deformation under working load to achieve the second load equalization.

[0008] Preferably, the component with the predetermined convex profile is the outer cylindrical surface of the support rollers of the upper mandrel and the lower mandrel.

[0009] Preferably, the support rollers mounted on the upper mandrel and the lower mandrel are provided with rolling support by a K-type needle roller assembly; The K-type needle roller assembly is a full-fill needle roller structure.

[0010] Preferably, the internal gear ring assembly (3) is composed of multiple circumferentially divided sector segments, and each sector segment is fixed to an internal gear ring spacer (306) by a positioning pin (304) and a connecting screw (305).

[0011] Preferably, the movable gear assembly includes an annular movable gear body having a plurality of radial through slots distributed along the circumference. The left end cap (202) and the right end cap (204) of the movable gear frame are respectively connected to the two ends of the axial direction of the movable gear frame body (203) to form a complete radial rectangular groove; the radial mounting structure is composed of the radial rectangular groove.

[0012] Preferably, the device further includes shock rollers (102) mounted on the shock roller profile of the eccentric shaft, and the shock rollers (102) are full-complement needle rollers. Preferably, it also includes a planetary gear reduction assembly (5) disposed at one axially upward end of the two columns of eccentric shaft assemblies.

[0013] Compared with the prior art, the advantages of the present invention are: (1) By using a triple load-sharing mechanism, the load-bearing capacity is improved and the precision requirements for processing and assembly are reduced: Using the central main support shaft as a common support point, the load of the left and right shock generators can be naturally distributed and balanced, so that the transmission on both sides can more evenly distribute the load and achieve the first level of load equalization. By setting up a radially elastic live tooth assembly, it is possible to automatically compensate for the meshing deviation between each live tooth assembly and the internal gear ring and shock wave generator caused by manufacturing and assembly errors through minute radial deformation, so that multiple live teeth in the circumferential direction can evenly share the load and achieve a second load sharing. The convex design of the mandrel and / or bushing in the live tooth assembly ensures that even if the mandrel bends under load, the pressure between the rollers at both ends and the contact surface remains relatively uniform, avoiding unilateral overload, thereby improving the load-bearing capacity of a single live tooth and achieving a third layer of load equalization. By setting up a triple load-sharing mechanism, the requirements for part form and position tolerances are greatly alleviated, and higher performance indicators can be achieved with more relaxed machining or assembly precision.

[0014] (2) Eliminate overturning torque and improve operational stability: By aligning the two shock wave arrays eccentrically in the same direction and placing a single main support shaft between the two shock wave arrays, the periodic iodine torque caused by the traditional 180° eccentric structure is fundamentally eliminated. This transforms the support system from a statically indeterminate problem into a statically determinate one, improving the stress state of the shaft, effectively reducing the end face runout and radial runout of the gear carrier, and thus enhancing the operating accuracy and stability of the reducer.

[0015] (3) The support structure of both the shock generator and the live gear assembly adopts the design of full complement needle roller bearings to improve the load-bearing capacity of the bearing parts; The design of the split-type assembly structure of the internal gear ring allows high-precision internal gear grinding to be achieved using a high-efficiency external cylindrical gear grinding process, which simplifies the processing difficulty and reduces the manufacturing cost. At the same time, it allows the end face teeth of the live gear frame to be changed from being distributed on three parts to being concentrated on one middle part, and the two sides can be simplified into a simple cover plate structure, which greatly reduces the manufacturing cost. By using the shock wave generator's co-directional eccentricity and internal gear ring segmented structure, the assembly process is simplified, unlike the complex 180° phase flip and precise adjustment required by the reverse eccentricity structure. This also helps maintain accuracy during long-term operation. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic cross-sectional view of the reducer described in this invention; Figure 2 This is a schematic diagram of the axial cross-sectional structure of the reducer described in this invention. Figure 1 Schematic diagram of the cross section at point AA; Figure 3 This is a schematic diagram of the axial cross-sectional structure of the internal gear ring assembly described in this invention; Figure 4 This is a cross-sectional view of the internal gear ring assembly described in this invention. Figure 3 Schematic diagram of the cross section at point BB; Figure 5 This is a schematic diagram of the axial cross-sectional structure of the movable gear assembly described in this invention; Figure 6 This is a cross-sectional view of the active tooth assembly described in this invention; Figure 7 This is a schematic diagram of the upper mandrel described in this invention; Figure 8 This is a schematic diagram of the structure of the lower mandrel described in this invention; Figure 9 This is a schematic diagram of the structure of the live gear roller sleeve described in this invention.

[0017] Among them: eccentric shaft assembly 1, axial limiting bearing 101, shock roller 102, shock roller flange 103, bearing cover 104, bearing cover screw 105, roller flange positioning pin 106, main support bearing 107, shock 108. Live gear assembly 2, bearing retaining ring 201, left end cover of live gear 202, live gear body 203, right end cover of live gear 204, left end cover screw of live gear 205, right end cover screw of live gear 206. Internal gear ring assembly 3, internal gear ring seal 301, seal ring support 302, internal gear ring 303, internal gear ring connecting pin 304, internal gear ring connecting screw 305, internal gear ring spacer 306, main bearing rolling element 307, seal ring support seal 308, internal gear ring gap seal 309. Live tooth assembly 4, live tooth collar 401, upper mandrel 402, K-type needle roller assembly 403, lower mandrel 404; Planetary gear reduction assembly 5. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments: like Figures 1-9 As shown, a double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator is described. Its core lies in achieving a triple load-sharing mechanism within the rolling gear reducer through systematic structural innovation. This systematically solves problems in existing technologies caused by reverse eccentric structures, such as overturning torque, uneven circumferential load distribution, stress concentration in individual teeth, and the resulting high-precision manufacturing costs. The triple load-sharing mechanism specifically involves: The structural design of using a double-row, co-directional eccentric shock wave generator with a single main support bearing in the middle eliminates the periodic overturning torque at its source and achieves natural and uniform load distribution between the two rows of shock wave generators, thus achieving the first level of load equalization.

[0019] The spindle of the live tooth assembly adopts a controllable radial elastic design, which enables it to undergo slight bending deformation adaptively under working load, thereby compensating for the difference in meshing force of one ring of live teeth caused by machining or assembly errors, achieving uniform distribution of circumferential load, and realizing a second layer of load equalization.

[0020] A predetermined convex profile is set on the live gear shaft core and rollers, so that when a single shaft is bent under force, the contact stress between the rollers at both ends and the shock wave generator and the internal gear ring can be automatically transferred to the middle, forming a uniform pressure distribution, thereby achieving a third load equalization inside the live gear assembly.

[0021] Through the synergistic effect of triple load sharing, the dependence on the close machining of reducer components is significantly reduced, enabling it to maintain high load capacity and high efficiency while also achieving stability and economy.

[0022] Specifically: like Figures 1-9 As shown, the reducer in this embodiment mainly consists of an eccentric shaft assembly 1, a movable gear frame assembly 2, an internal gear ring assembly 3, a movable gear assembly 4, and a planetary gear reduction assembly 5. Figures 1-2As shown, the eccentric shaft assembly 1 consists of an axial limiting bearing 101, shock rollers 102, shock roller flanges 103, a bearing cap 104, a bearing cap screw 105, a roller flange locating pin 106, a main support bearing 107, and a shock generator 108. There are two shock generators 108, with the eccentricity directions of the two shock generators being the same. The main support bearing 107 is installed axially between the two shock generators 108; in this embodiment, the main support bearing 107 can be a cylindrical roller bearing. By using a main support bearing 107 in conjunction with two shock generators eccentrically aligned in the same direction, the complex support structure of the originally statically indeterminate problem is simplified to a statically determinate structure. This allows the radial loads acting on the two shock generators to be naturally balanced by the main support bearing, thereby eliminating the overturning torque caused by the opposite eccentric torques on both sides. This greatly improves the stress state of the main shaft and enhances the rigidity and stability of the transmission system.

[0023] like Figure 2 , Figures 5-9 As shown, the movable gear frame assembly 2 is a rigid frame that provides radial guidance for the movable gear assembly. The movable gear frame assembly 2 includes a bearing retaining ring 201, a left end cap 202, a movable gear body 203, a right end cap 204, a left end cap screw 205, and a right end cap screw 206. The annular movable gear body 203 has multiple radially distributed through slots along its circumference. These through slots are connected to the left end cap 202 and the right end cap 204 of the movable gear frame on both sides by screws, forming radial rectangular grooves, which constitute the mounting and guiding structure of the movable gear assembly 4.

[0024] like Figures 6-9 As shown, the movable tooth assembly 4 is the core carrier for achieving the second and third load-sharing effects of this invention. Each movable tooth assembly 4 includes a movable tooth collar 401, an upper mandrel 402, a K-type needle roller assembly 403, and a lower mandrel 404. The upper mandrel 402 and lower mandrel 404 are respectively located on the upper and lower parts of the movable tooth collar 401. Each mandrel is equipped with a load-bearing roller. The mandrel is designed to have a certain radial elastic capacity, which can be designed and controlled through material properties and the cross-sectional geometry of the mandrel. During operation, when the loads borne by the movable tooth assemblies 4 at different positions are inconsistent, these mandrels can produce slight elastic bending deformation, automatically adjusting their positions, thereby enabling the pressure to be effectively transmitted and balanced among the multiple movable teeth in the circumferential direction, thus achieving the second load-sharing effect and significantly reducing load concentration caused by manufacturing and assembly errors.

[0025] Furthermore, the working outer cylindrical surface (the surface in contact with the shock wave generator or internal gear ring) of the upper spindle 402, lower spindle 404, or the load-bearing roller mounted thereon of the live gear assembly 4 is set with a certain convex profile. The cross-section at this convex profile can be circular. When the spindle bends due to the overall load, the setting of the convex profile ensures that the point of force application in the contact area between the roller and the shock wave generator or internal gear ring does not shift excessively. This achieves uniform force distribution on the roller sleeves at both ends of the live gear spindle and prevents the load in the middle of the spindle from deviating from the center position, effectively improving the load-bearing capacity of the reducer and preventing abnormal damage.

[0026] In addition, to support high load contact, the rolling supports in the live gear assembly 4, such as the K-type needle roller assembly 403 connecting the spindle and the roller, and the rolling element 102 on the shocker, are all set with a full complement needle roller structure. The needle rollers are arranged more closely, providing more rolling elements in the same space, thereby greatly improving the ultimate load capacity of the bearing. At the same time, it does not eliminate the risk of cage breakage or failure under extreme working conditions.

[0027] like Figures 1-4 As shown, the internal gear ring assembly 3 consists of an internal gear ring seal 301, a seal ring support 302, an internal gear ring 303, an internal gear ring connecting pin 304, an internal gear ring connecting screw 305, an internal gear ring spacer 306, a main bearing rolling element 307, a seal ring support seal 308, and an internal gear ring gap seal 309. The internal gear ring 303 is composed of multiple circumferentially separated sector segments. These sector segments are precisely positioned by locating pins 304 and fastened to a central internal gear ring spacer 306 by high-strength internal gear ring connecting screws 305. The gaps between them are sealed by the internal gear ring gap seal 309. This segmented design transforms the internal gear ring, which originally required complex grinding in a large internal bore, into a process where each sector segment can be precisely ground using a high-efficiency, high-precision external cylindrical gear grinding machine, similar to machining ordinary external gears. After grinding, the parts are assembled, thus achieving a high-precision internal tooth surface that meets the requirements with lower cost and better processability.

[0028] To achieve a larger overall transmission ratio, a planetary gear reduction assembly 5 can be integrated on one side of the axial direction of the two shock generators 108. This assembly includes a sun gear, planet gears, and a planet carrier, thus forming a two-stage reduction structure of planetary reduction + live gear reduction. This design also makes fuller use of the internal axial space of the structure, making the entire reduction mechanism more compact. The planetary gear reduction assembly 5 is located at the input end of the reducer. During cooperative operation, the sun gear of the planetary gear reduction assembly 5 is driven to rotate by a power device such as a servo motor. After the planet gears mesh, the reduced power drives the eccentric shaft assembly 1, which is integrally or rigidly connected to the planet carrier, to rotate. The two rows of shock generators 108 on the eccentric shaft, which are eccentric in the same direction, then perform a translational motion with a radius of rotation. This motion drives the rolling elements indicated by the shock generator profile to reciprocate at least one revolution of the live gear assembly's delayed radial groove. Since the internal gear ring is fixed and the roller on the upper part of the live gear assembly 4 always interacts with the meshing surface of the internal gear ring, the swing motion cup of the live gear assembly 4 is limited to tangential force, which in turn drives the live gear frame assembly 2 to rotate in the same direction at a speed that is significantly reduced relative to the input shaft, thereby achieving a high reduction ratio power output.

[0029] In summary, this invention first employs a first-level load-sharing mechanism consisting of "co-directional eccentricity + centrally located single bearing," which eliminates periodic overturning torques from a mechanical perspective, significantly improving the dynamic stiffness and operational smoothness of the reducer while reducing vibration and noise. Secondly, the second and third-level load-sharing mechanisms, achieved through the design of the elasticity and convexity of the live gear spindle, significantly increase the reducer's tolerance to manufacturing and assembly errors. This allows for the use of relatively relaxed manufacturing tolerances and assembly processes while maintaining the same load-bearing capacity and transmission accuracy, directly leading to reduced manufacturing costs and increased production efficiency. Furthermore, the synergistic effect of the triple load-sharing mechanism evenly distributes the load to more meshing live gears, optimizing the stress distribution of each live gear contact pair, thereby significantly improving the overall overload capacity, service life, and transmission efficiency. Finally, the segmented design of the internal gear ring optimizes machining processes, the application of full complement needle roller bearings enhances load-bearing stability, and the co-directional eccentric structure simplifies the assembly process, all contributing to the invention's high performance while also ensuring better feasibility and implementation.

[0030] It should be noted that, based on the same inventive concept, this invention can also have other real-time configurations. For example, the convex profile can be machined not only on the outer surface of the bearing roller, but also modified to a convex design of the inner hole of the bushing, or a convex design at three points on the spindle, etc. The planetary gear reduction assembly 5 can be replaced by other forms of reduction mechanisms, or directly omitted to form a single-stage live gear reducer. Furthermore, the input and output interfaces of the reducer can be interchanged as needed, such as a fixed live gear frame with output from an internal gear ring. All the above-mentioned modifications and substitutions, as long as their core adopts the above-mentioned triple load-sharing concept, should fall within the protection scope of this invention.

[0031] The above embodiments are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description, and thus all changes falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention.

Claims

1. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator, characterized in that... ,include: Eccentric shaft assembly (1), live gear frame assembly (2), internal gear ring assembly (3), at least one ring of live gear assembly (4). The eccentric shaft assembly (1) includes an eccentric shaft on which two rows of shock generators (108) are eccentrically aligned; a main support bearing (107) is disposed on the eccentric shaft and located in the middle of the two rows of eccentric shock generators (108), for supporting the eccentric shaft and balancing the load of the two rows of shock generators (108) to achieve the first load equalization. The live tooth assembly (4) is arranged circumferentially within the radial mounting structure of the live tooth frame assembly (2); the live tooth assembly (4) is constructed as a spindle structure with elastic deformation capability to compensate for the uneven load between each live tooth assembly (4) and achieve a second load equalization. Furthermore, at least one row of rollers and / or its supporting spindle in the live tooth assembly (4) that are in contact with the shock generator (108) and the internal gear ring are configured to have a predetermined convex profile, so that when the spindle is subjected to bending deformation, the contact pressure of the rollers at both ends of the live tooth assembly (4) is evenly distributed, thereby achieving a third load equalization.

2. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 1, characterized in that: The movable tooth assembly (4) includes: Live toothed ring (401); The upper mandrel (402) and the lower mandrel (404) are supported by the live toothed collar (401). Rollers mounted on the upper mandrel (402) and the lower mandrel (404); The upper mandrel (402) and the lower mandrel (404) constitute the mandrel structure.

3. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 2, characterized in that: The upper mandrel (402) and / or the lower mandrel (404) have a preset elastic deformation amount, which enables them to generate elastic bending deformation under working load to achieve the second weight distribution load.

4. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 2, characterized in that: The component with the predetermined convex profile is the outer cylindrical surface of the support rollers of the upper mandrel (402) and the lower mandrel (404).

5. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 4, characterized in that: The support rollers mounted on the upper mandrel (402) and the lower mandrel (404) are rolled and supported by the K-type needle roller assembly (403); The K-type needle roller assembly (403) is a full-fill needle roller structure.

6. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 1, characterized in that: The internal gear ring assembly (3) is composed of multiple circumferentially divided sector segments, each sector segment being fixed to an internal gear ring spacer (306) by a positioning pin (304) and a connecting screw (305).

7. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 1, characterized in that: The movable gear assembly (2) includes an annular movable gear body (203) on which a plurality of radial through slots are provided along the circumference; The left end cap (202) and the right end cap (204) of the movable gear frame are respectively connected to the two ends of the axial direction of the movable gear frame body (203) to form a complete radial rectangular groove; the radial mounting structure is composed of the radial rectangular groove.

8. A double-layer roller rolling gear reducer with a double-row co-directional eccentric shock wave generator according to claim 1, characterized in that: It also includes a shock roller (102) mounted on the shock profile of the eccentric shaft, and the shock roller (102) is a full-fill needle roller structure.

9. The reducer according to claim 1, characterized in that, It also includes a planetary gear reduction assembly (5) disposed at one axially upward end of the two columns of the eccentric shaft assembly (1).

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