Planetary speed reducer with large speed ratio and small tooth difference

Abstract

The invention relates to the technical field of transmission devices, in particular to a large-speed-ratio small-tooth-difference planetary reduction gear which comprises a fixed inner gear ring, an output inner gear ring and a transmission structure. The output inner gear ring is internally connected with the fixed inner gear ring through a connecting bearing; the transmission structure comprises an input shaft, a planet carrier, a first sun gear and a second sun gear; a tooth number difference is kept between the first sun gear and the second sun gear; the planet carrier comprises a planet sleeve, a planet plate and a planet shaft; a first planet wheel is mounted on the left planet shaft, a second planet wheel is mounted on the right planet shaft, and the radius of the first planet wheel is smaller than that of the second planet wheel; one side of the first planet gear is in meshing transmission with the first sun gear, and the other side is in meshing transmission with the fixed inner gear ring; one side of the second planet gear is in meshing transmission with the second sun gear, and the other side is in meshing transmission with the output inner gear ring. An eccentric shaft mechanism is omitted, manufacturing is easy, and dynamic balance is good; meanwhile, the noise is low, the transmission precision is high, and the small-space large-speed-ratio speed reduction requirement is met.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission devices, and in particular to a planetary reduction device with a large speed ratio and small tooth difference. Background Art

[0002] Conventional planetary reducers have the advantage of high power transmission density, but within a certain volume, it is impossible to achieve a larger speed ratio through two-stage reduction. If a larger speed ratio is required, the number of planetary gears needs to be increased, which will also cause problems of large volume and high cost. Specifically, if a traditional planetary reducer wants to achieve a reduction ratio of more than 100, it generally requires more than four stages of reduction. It needs to include multiple planet carriers, multiple sun gears, multiple planetary gears, multiple inner rings and other components. The reducer is large and long. If the space is limited, it cannot meet the requirements of a larger reduction ratio. At the same time, since the planet carrier of the multi-stage reduction is running in a free state, it will also cause problems of poor transmission accuracy and high noise.

[0003] Traditional speed reducers with small tooth difference mostly achieve the purpose of speed reduction by driving two or more eccentric gears to mesh with the inner gear ring through one or more eccentric shafts, and have the advantage of a large speed ratio. The existing technologies include RV speed reducers, planetary speed reducers with small tooth difference, cycloid speed reducers, etc., although a relatively large reduction ratio can be achieved through more than three stages of reduction. However, the principles of the above speed reducers all have eccentric shaft mechanisms, and the eccentric shaft has the disadvantages of complex manufacturing process, poor dynamic balance, high noise, high linear speed at the inner gear ring, and high heat generation. In summary, how to achieve a larger reduction ratio requirement within an effective spatial volume through a single-stage reduction of a sun gear and a planetary carrier, and to design a new transmission device for the purpose of high transmission power density and high precision, is a problem that urgently needs to be solved. Summary of the invention

[0004] In order to solve the above-mentioned shortcomings and deficiencies in the use of prior art reduction transmissions, the present invention provides a planetary reduction device with a large speed ratio and small tooth difference, which removes the eccentric shaft mechanism, is simple to manufacture, has good dynamic balance, low noise, high transmission accuracy, and can meet the requirements of large speed ratio reduction in a small space.

[0005] The present invention adopts the following technical solutions to achieve the above purpose: A planetary reduction device with a large speed ratio and a small tooth difference, comprising a fixed internal gear ring, an output internal gear ring and a transmission structure; the fixed internal gear ring is fixedly connected to the external end surface and is provided with internal teeth inside; the output internal gear ring is internally connected to the fixed internal gear ring through a connecting bearing, is also provided with internal teeth, and the two maintain relative rotation; the transmission structure comprises an input shaft, a planet carrier, a first sun gear and a second sun gear; the input shaft is distributed on the left and right, and extends coaxially and passes through the fixed internal gear ring and the output internal gear ring; the first sun gear and the second sun gear are both arranged in the middle of the input shaft, and the three are integrally formed, and the first sun gear and the second sun gear maintain a difference in the number of teeth; the planet carrier is a pair of There are two groups of planetary carriers distributed on the left side, each of which includes a planetary sleeve, a planetary disk and a planetary shaft; the planetary sleeve adapter is mounted on the input shaft, and the planetary disk is coaxially arranged on the planetary sleeve; the planetary shaft is arranged on the planetary disk, and is a plurality of planetary shafts evenly distributed in an annular shape; a first planetary gear is mounted on the planetary shaft of the planetary carrier distributed on the left side, and a second planetary gear is mounted on the planetary shaft of the planetary carrier distributed on the right side, and the radius of the first planetary gear is smaller than that of the second planetary gear; one side of the first planetary gear maintains meshing transmission with the first sun gear, and the other side maintains meshing transmission with the fixed inner gear ring; one side of the second planetary gear maintains meshing transmission with the second sun gear, and the other side maintains meshing transmission with the output inner gear ring.

[0006] As a preferred technical solution: the fixed inner gear ring is arranged on the left side of the output inner gear ring; the fixed inner gear ring includes a fixed sleeve and a cover plate; the cross-section of the fixed sleeve is a concave structure, and a through hole is opened on the right end face, and a fixed tooth is arranged on the side wall of the through hole, and the fixed tooth is meshed with the first planetary gear for transmission; and a bearing step is also provided on the outside of the fixed sleeve for adapting the installation of the connecting bearing to connect the output inner gear ring; the cover plate is a circular structure, and a mounting hole adapted to the central axis is opened in the center; a groove is opened on the inner side of the cover plate; the cover plate and the fixed sleeve are an integrally formed structure.

[0007] A further preferred technical solution is as follows: at the groove, the inner side of the planetary sleeve of the planetary carrier on the left side is connected to the input shaft through a center bearing, and the outer side is connected to the side wall of the groove through a planetary bearing; at the mounting hole, an oil seal is also provided between the input shaft and the cover plate.

[0008] A further preferred technical solution: the output inner gear ring includes an output sleeve and a boss; the output sleeve is a columnar structure with an open left end and a solid surface at the right end, and the inner diameter of the output sleeve is equal to the outer diameter of the fixed sleeve; a groove is provided at the center of the inner wall of the right end of the output sleeve; the boss is an annular structure and is arranged on the inner wall of the output sleeve, and the side wall of the boss is provided with output teeth, and the output teeth maintain meshing transmission with the second planetary gear; and the output sleeve and the boss are an integrally formed structure.

[0009] A further preferred technical solution: at the slot, the planet sleeve of the planet carrier on the right side is connected to the input shaft via a center bearing on the inner side, and connected to the slot side wall on the outer side via a planet bearing; the two planetary disks are connected via a connecting rod to form an integrated structure.

[0010] As a preferred technical solution: the fixed inner gear ring is arranged on the right side of the output inner gear ring; the fixed inner gear ring is a hollow cylindrical structure, and a fixing hole is opened on the left end face, and the side wall of the fixing hole is provided with fixed teeth, and the fixed teeth maintain meshing transmission with the first planetary gear; and a fixing groove is opened in the center of the inner wall at the right end of the fixed inner gear ring, which is used to adapt to the rotatable installation of the input shaft and the planetary sleeve; the outer side wall of the fixed inner gear ring is also provided with a bearing step for adapting the installation of the connecting bearing.

[0011] A further preferred technical solution: the output inner gear ring includes a base plate, a ring body and a pillow block; the ring body is a columnar structure, and the inner diameter of the ring body is equal to the outer diameter of the fixed inner gear ring; the pillow block is an annular structure, and is fixedly arranged in the inner middle part of the ring body, and the inner wall of the pillow block is provided with output teeth, and the output teeth are meshed with the second planetary gear for transmission; the base plate is a solid plate, and a circular hole for adapting to the input shaft is opened at the left end, and a base groove is provided on the right side wall of the base plate for adapting to the rotatable installation of the input shaft and the planetary sleeve; wherein, the right end of the planetary shaft of the planetary frame distributed on the left side is connected to the planetary disk of the planetary frame distributed on the right side; the right end of the planetary shaft of the planetary frame distributed on the right side is connected to the planetary disk of the planetary frame distributed on the left side.

[0012] A further preferred technical solution: the number of teeth of the fixed teeth is equal to the number of teeth of the output teeth.

[0013] A further preferred technical solution is that there is a difference in the number of teeth between the fixed teeth and the output teeth.

[0014] A further preferred technical solution: an oil seal is further provided at the connection between the fixed inner gear ring and the output inner gear ring.

[0015] Compared with the prior art, the invention has the following beneficial effects: large transmission ratio: the minimum tooth number difference of the sun gear of the reduction device is 1 tooth, and the single-stage transmission ratio can reach more than 100, which can achieve a larger deceleration requirement in a smaller space; Compact structure: Since there are only two inner gear rings and one planet carrier in the axial space, the entire volume is relatively short, which saves structural space. Compared with the traditional planetary reducer with the same speed ratio, the length can be compressed by more than 30%; compared with the ordinary cylindrical gear reducer with the same power, when the transmission ratio is equal, the volume and weight can be reduced by about 40%; Simple manufacturing process: Since the eccentric shaft of the traditional small-tooth difference reducer is omitted, the manufacturing process is simplified and the dynamic balance of the structure is improved; Light weight and low cost: Compared with planetary reducers with the same speed ratio, it saves more than 20% of materials, effectively reducing manufacturing costs; Greater load-bearing capacity: Due to the internal meshing transmission, the two meshing gear teeth are one concave and one convex, the curvature centers of the two teeth are in the same direction, and the curvature radius is close to being equal, so the contact area is large, which greatly improves the contact strength of the gear teeth; at the same time, short teeth can be used to improve the bending strength of the gear teeth. In addition, when the transmission is small-tooth difference, it is not a pair of gear teeth that mesh, but multiple groups of gear teeth that are in contact and force at the same time, so the load-bearing capacity is large; Smooth operation and low noise: Since bearings can be installed between the output inner gear ring and the fixed inner gear ring, the planetary carrier and the two inner gear rings, the sun gear and the planetary carrier or between the two inner gear rings, the operation is smoother, the impact and vibration during the transmission process are smaller, and the noise is reduced; Wide range of applications: The outer periphery of the inner gear ring and one end face as the output component can be used as output connections, which can adapt to different installation requirements in various scenarios. Therefore, it has a wide range of applications, ranging from robot joints to metallurgical and mining machinery, engineering machinery, etc.; the shaft end as the output component can also be used as an output connection, which is suitable for shaft transmission connection applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a working principle diagram of Embodiment 1 of the present invention; Figure 3 is a three-dimensional diagram of a planet carrier according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 5 This is a working principle diagram of Embodiment 2 of the present invention; Figure 6 This is a three-dimensional diagram of the planet carrier of embodiment 2 of the present invention.

[0018] In the figure: 1-fixed inner gear ring, 11-fixed sleeve, 12-cover plate, 13-through hole, 14-fixed tooth, 15-bearing step, 16-mounting hole, 17-groove, 18-center bearing, 19-planetary bearing, 2-output inner gear ring, 21-output sleeve, 22-boss, 23-solid surface, 24-slot, 25-output tooth, 3-transmission structure, 31-input shaft, 32-planet carrier, 33-first sun gear, 34-second sun gear, 35-planet sleeve, 36-planetary disk, 37-planetary shaft, 38-connecting rod, 4-connecting bearing, 5-first planetary gear, 6-second planetary gear, 7-oil seal, 81-fixed hole, 82-fixed groove, 91-base plate, 92-ring body, 93-pillar platform, 94-circular hole, 95-base groove. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "provided with" that may appear should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0021] Example 1: Figures 1 to 3 Shown: A planetary reduction device with a large speed ratio and a small tooth difference, comprising a fixed inner ring gear 1, an output inner ring gear 2 and a transmission structure 3. This reduction device is designed to meet the use requirements of achieving a large reduction ratio in a smaller space. It is a planetary reduction device with a large speed ratio and a small tooth difference. The fixed inner ring gear 1 is fixedly connected to the external end face and is provided with teeth inside. The output inner ring gear 2 is connected to the fixed inner ring gear 1 through a connecting bearing 4, and is also provided with teeth, and the two maintain relative rotation. The fixed inner ring gear is a gear ring with teeth inside, which mainly plays the role of a fixed frame, and at the same time blocks the torque transmitted from the sun gear through the planetary gear, thereby making the planetary frame revolve around the sun gear. One of the two inner ring gears is a fixed end, and the other is an output end, and the two inner ring gears have the same number of teeth.

[0022] like Figure 1As shown: In this embodiment, the preferred technical solution is that the fixed inner gear ring 1 is arranged on the left side of the output inner gear ring 2. The fixed inner gear ring 1 includes a fixed sleeve 11 and a cover plate 12. Figure 1 As shown: the cross section of the fixed sleeve 11 is a concave structure, and a through hole 13 is opened on the right end face. A fixed tooth 14 is set on the inner side wall of the through hole 13, and the fixed tooth 14 is meshed with the first planetary gear 5 for transmission. Because it is an internal meshing transmission, the two meshing gear teeth are one concave tooth (fixed tooth) and the other is a convex tooth (first planetary gear). The curvature centers of the two teeth are in the same direction, and the curvature radius is close to being equal, so the contact area is large, which greatly improves the contact strength of the gear teeth; at the same time, short teeth can be used to manufacture, which can also improve the bending strength of the gear teeth. In addition, when the transmission is small-tooth difference, it is not a pair of gear teeth that mesh, but multiple groups of gear teeth that are in contact and force at the same time, so the load-bearing capacity is large.

[0023] like Figure 1 As shown: Among them, a bearing step 15 is also provided on the outside of the fixed sleeve 11, which is used to adapt and install the connecting bearing 4 to connect the output inner gear ring 2; the purpose of such a setting is that the planetary carrier is different from the traditional planetary reducer, and the bearing steps can be retained at both ends, and the two ends of the planetary carrier can be fixed between the fixed inner gear ring and the output inner gear ring respectively, so as to achieve the purpose of stable operation. The cover plate 12 is a circular structure, and a mounting hole 16 for adapting to the central axis is opened in the center. A groove 17 is opened on the inside of the cover plate 12; the cover plate 12 and the fixed sleeve 11 are an integrally formed structure. At the groove 17, the inner side of the planetary sleeve 35 of the planetary carrier 32 on the left side is connected to the input shaft 31 through the central bearing 18, and the outer side is connected to the side wall of the groove 17 through the planetary bearing 19. At the mounting hole 16, an oil seal 7 is also provided between the input shaft 31 and the cover plate 12. An oil seal 7 is also provided at the connection between the fixed inner gear ring 1 and the output inner gear ring 2, and such a setting is used to ensure sealing. Since the output inner gear ring and the fixed inner gear ring, the planet carrier and the two inner gear rings, the sun gear and the planet carrier or between the two inner gear rings can be installed with bearings for positioning, the operation is smoother, the impact and vibration during the transmission process are smaller, and the noise is reduced. The bearings at both ends of the sun gear can be fixed on the fixed inner gear ring and the output inner gear ring, or fixed inside the planet carrier, which improves the running accuracy. The output inner gear ring and the fixed inner gear ring are connected together by one or more bearings, with high concentricity and smooth operation.

[0024] like Figure 1As shown: In this embodiment, it is preferred to adopt a structural design in which the number of teeth of the fixed teeth 14 and the output teeth 25 are equal, so that the transmission requirement of a large speed ratio can be achieved through the difference in the number of teeth of the sun gear. Among them, the output inner gear ring 2 includes an output sleeve 21 and a boss 22. The output sleeve 21 is a columnar structure, and the left end is open and the right end is a solid surface 23. The outer periphery of the inner gear ring and one end surface of the solid surface as the output component can be used as an output connection, which can adapt to the different installation requirements of various scenes. Therefore, it has a wide range of applications, ranging from the joints of robots to metallurgical mining machinery, engineering machinery, etc. The inner diameter of the output sleeve 21 is equal to the outer diameter of the fixed sleeve 11, which is convenient for adaptation and installation. A slot 24 is provided in the center of the inner wall of the right end of the output sleeve 21. The boss 22 is an annular structure and is arranged on the inner wall of the output sleeve 21. The side wall of the boss 22 is provided with an output tooth 25, and the output tooth 25 is meshed with the second planetary gear 6 for transmission; and the output sleeve 21 and the boss 22 are an integrally formed structure. At the slot 24, the planet sleeve 35 of the planet carrier 32 on the right side is connected to the input shaft 31 through the center bearing 18, and the outer side is connected to the side wall of the slot 24 through the planet bearing 19. Since there are only two inner gear rings and one planet carrier in the axial space, the entire volume is relatively short, saving structural space, and the length can be compressed by more than 30% compared with the traditional planetary reducer with the same speed ratio; compared with the ordinary cylindrical gear reducer with the same power, when the transmission ratio is equal, the volume and weight can be reduced by about 40%.

[0025] like Figure 1 As shown: In this embodiment, the transmission structure 3 includes an input shaft 31, a planet carrier 32, a first sun gear 33 and a second sun gear 34. Figure 3 As shown: the input shaft 31 is distributed on the left and right, and coaxially extends and distributes through the fixed inner gear ring 1 and the output inner gear ring 2. The first sun gear 33 and the second sun gear 34 are both arranged in the middle of the input shaft 31, and the three are integrally formed. The first sun gear 33 and the second sun gear 34 maintain a difference in the number of teeth. The minimum difference in the number of teeth is 1 tooth, and the single-stage transmission ratio can reach more than 100, which can achieve a larger reduction demand in a smaller space. By driving two coaxial sun gears with different numbers of teeth on the same planetary carrier at the same time, plus a fixed inner gear ring and an output inner gear ring composed of a first-stage reduction transmission chain, a large speed ratio and a small tooth difference reduction structure can be achieved. Two planetary gears with different numbers of teeth are installed on the same planetary carrier (these planetary gears can be multiple sets in parallel), and two coaxial sun gears with different numbers of teeth simultaneously drive two planetary gears with different numbers of teeth on an integrated planetary carrier. Driven by the sun gear, the two planetary gears drive the fixed inner gear ring and the output inner gear ring respectively.

[0026] like Figure 3As shown: In this embodiment, the planet carrier 32 is symmetrically distributed in two groups, and each group of the planet carrier 32 includes a planet sleeve 35, a planet disk 36 and a planet shaft 37. The planet sleeve 35 is mounted on the input shaft 31 in an adaptive manner, and the planet disk 36 is coaxially arranged on the planet sleeve 35; the planet shaft 37 is arranged on the planet disk 36, and is a plurality of annularly evenly distributed. The first planetary gear 5 is mounted on the planetary shaft 37 of the planet carrier 32 on the left side, and the second planetary gear 6 is mounted on the planetary shaft 37 of the planet carrier 32 on the right side, and the radius of the first planetary gear 5 is smaller than the radius of the second planetary gear 6. One side of the first planetary gear 5 is meshed with the first sun gear 33, and the other side is meshed with the fixed inner gear ring 1. One side of the second planetary gear 6 is meshed with the second sun gear 34, and the other side is meshed with the output inner gear ring 2. The two planetary disks 36 are connected by a connecting rod 38 to form an integrated structure. The planetary carrier is equipped with multiple sets of planetary gears, which serve as a cage to fix the multiple planetary gears together and orbit around the sun gear. The invention integrates the advantages of traditional planetary reducers and reducers with small tooth difference, shields the disadvantages of both, removes the eccentric shaft mechanism, is simple to manufacture, and has good dynamic balance. Since the planetary carrier runs with bearing support at both ends, it has low noise and high transmission accuracy, and realizes the reduction demand of large speed ratio in a small space.

[0027] The specific reduction transmission principle is as follows: Figure 2 As shown: it is composed of a first stage, two coaxial but different numbers of teeth of the first sun gear and the second sun gear, which simultaneously drive the first planetary gear and the second planetary gear of two different radii on the integrated planetary frame, and then the first planetary gear meshes with the fixed teeth of the fixed inner gear ring. The second planetary gear meshes with the output teeth of the output inner gear ring. The number of teeth of the first sun gear matches the first planetary gear. The number of teeth of the second sun gear matches the second planetary gear. In this technical solution, a structural design in which the number of teeth of the fixed inner gear ring and the output inner gear ring are the same is adopted at the same time. In this way, when the sun gear drives the planetary gear at the same time, since the number of teeth of the two inner gear rings is the same and the number of teeth of the two sun gears is different, the two inner gear rings driven by the two planetary gears have a fast speed and a slow speed (specifically, the output inner gear ring has a relatively slow speed), which forms a rotation angle difference with different speeds, thereby achieving the purpose of differential reduction; the planetary gears can be set as multiple sets of parallel structures according to the space. The design of this reduction mechanism can achieve a relatively large reduction ratio in a smaller volume space.

[0028] The solution of the present invention can be superimposed on each other as needed, and can also be superimposed on a traditional planetary small-tooth difference reduction mechanism to achieve a larger reduction ratio requirement.

[0029] Embodiment 2: A planetary reduction device with a large speed ratio and a small tooth difference. The technical solution of this embodiment is substantially similar to that of embodiment 1, except that: Figures 4 to 6As shown: the fixed inner gear ring 1 is arranged on the right side of the output inner gear ring 2. This method is mainly for the application scenario of output torque at the shaft end, and the input shaft also serves as the torque output side. The fixed inner gear ring 1 is a hollow cylindrical structure, and a fixing hole 81 is provided on the left end face. The side wall of the fixing hole 81 is provided with a fixing tooth 14, and the fixing tooth 14 maintains meshing transmission with the first planetary gear 5. A fixing groove 82 is provided in the center of the inner wall at the right end of the fixed inner gear ring 1, which is used to adapt to the rotatable installation of the input shaft 31 and the planetary sleeve 35. A bearing is also provided thereto to facilitate stable rotation.

[0030] like Figure 4 As shown: wherein, the outer wall of the fixed inner gear ring 1 is also provided with a bearing step 15 for adapting and installing the connecting bearing 4. Specifically, the output inner gear ring 2 includes an integrally formed base plate 91, a ring body 92 and a pillow block 93. The ring body 92 is a columnar structure, and the inner diameter of the ring body 92 is equal to the outer diameter of the fixed inner gear ring 1; the pillow block 93 is an annular structure, and is fixedly arranged in the inner middle part of the ring body 92, and the inner wall of the pillow block 93 is provided with output teeth, and the output teeth are meshed with the second planetary gear 6 for transmission; the base plate 91 is a solid plate, and a circular hole 94 for adapting to the input shaft 31 is opened at the left end, and a base groove 95 is provided on the right side wall of the base plate 91 for adapting to the rotatable installation of the input shaft 31 and the planetary sleeve 35. As shown Figure 6 As shown: wherein, the right end of the planet shaft 37 of the planet carrier 32 on the left is connected to the planet disk 36 of the planet carrier 32 on the right; the right end of the planet shaft 37 of the planet carrier 32 on the right is connected to the planet disk 36 of the planet carrier 32 on the left, specifically by welding. The purpose of such a setting is to eliminate the redundant connecting rod support structure, while ensuring the integrated structure of the planet carrier, enhancing the overall stability of the planet carrier. At the same time, in the preferred solution of this embodiment, there is a difference in the number of teeth between the fixed teeth 14 and the output teeth. The purpose of such a setting is to achieve a higher speed ratio transmission requirement in Example 1 through the structural design of the difference in the number of teeth of the inner ring plus the difference in the number of teeth of the sun gear. The single-stage transmission ratio can reach more than 200, which can achieve a larger deceleration requirement in a smaller space.

[0031] The specific reduction transmission principle is as follows: Figure 5As shown: First, the first sun gear and the second sun gear input high-speed transmission torque through the input shaft, and then the torque is transmitted from the first sun gear to the first planetary gear, which meshes with the fixed inner gear ring through the first planetary gear; the torque of the second sun gear is transmitted to the second planetary gear. Through the second planetary gear, it meshes with the output inner gear ring; the first planetary gear and the second planetary gear are installed together on an integrated planetary frame. Since the fixed inner gear ring is fixed as a support body, the torque is synchronously rotated by the two planetary gears while the planetary frame also revolves around the sun gear, transmitting the torque to the output inner gear ring. Since the two inner gear rings have the same number of teeth, when two sun gears with different numbers of teeth drive two planetary gears with different numbers of teeth at the same time, a speed difference is generated between the fixed inner gear ring and the output inner gear ring, forming a deceleration principle with a small tooth difference, and a very large speed ratio.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A planetary reduction gear with large speed ratio and small tooth difference, characterized in that: It includes a fixed inner gear ring, an output inner gear ring and a transmission structure; the fixed inner gear ring is fixedly connected to the external end surface and is provided with teeth inside; the output inner gear ring is connected to the fixed inner gear ring through a connecting bearing and is also provided with teeth, and the two maintain relative rotation; the transmission structure includes an input shaft, a planet carrier, a first sun gear and a second sun gear; the input shaft is distributed on the left and right, and extends coaxially and passes through the fixed inner gear ring and the output inner gear ring; the first sun gear and the second sun gear are both arranged in the middle of the input shaft, and the three are integrally formed, and the first sun gear and the second sun gear maintain a difference in the number of teeth; the planet carrier is two symmetrically distributed groups, each group The planetary carrier includes a planetary sleeve, a planetary disk and a planetary shaft; the planetary sleeve adapter is installed on the input shaft, and the planetary disk is coaxially arranged on the planetary sleeve; the planetary shaft is arranged on the planetary disk, and is a plurality of annularly evenly distributed; a first planetary gear is installed on the planetary shaft of the planetary carrier on the left side, and a second planetary gear is installed on the planetary shaft of the planetary carrier on the right side, and the radius of the first planetary gear is smaller than the radius of the second planetary gear; one side of the first planetary gear maintains meshing transmission with the first sun gear, and the other side maintains meshing transmission with the fixed inner gear ring; one side of the second planetary gear maintains meshing transmission with the second sun gear, and the other side maintains meshing transmission with the output inner gear ring.

2. A planetary reduction gear with large speed ratio and small tooth difference according to claim 1, characterized in that: The fixed inner gear ring is arranged on the left side of the output inner gear ring; the fixed inner gear ring includes a fixed sleeve and a cover plate; the cross section of the fixed sleeve is a concave structure, and a through hole is opened on the right end face, and a fixed tooth is arranged on the side wall of the through hole, and the fixed tooth is meshed with the first planetary gear for transmission; and a bearing step is also provided on the outside of the fixed sleeve for adapting the installation of the connecting bearing to connect the output inner gear ring; the cover plate is a circular structure, and a mounting hole adapted to the central axis is opened in the center; a groove is opened on the inner side of the cover plate; the cover plate and the fixed sleeve are an integrally formed structure.

3. A planetary reduction gear with large speed ratio and small tooth difference according to claim 2, characterized in that: At the groove, the planet sleeve of the planet carrier on the left side is connected to the input shaft through a central bearing on the inner side, and is connected to the groove side wall on the outer side through a planet bearing; at the mounting hole, an oil seal is also provided between the input shaft and the cover plate.

4. A planetary reduction gear with large speed ratio and small tooth difference according to claim 3, characterized in that: The output inner gear ring includes an output sleeve and a boss; the output sleeve is a columnar structure with an opening at the left end and a solid surface at the right end, and the inner diameter of the output sleeve is equal to the outer diameter of the fixed sleeve; a groove is provided at the center of the inner wall of the right end of the output sleeve; the boss is an annular structure and is arranged on the inner wall of the output sleeve, and the side wall of the boss is provided with output teeth, and the output teeth are meshed and transmitted with the second planetary gear; and the output sleeve and the boss are an integrally formed structure.

5. A planetary reduction gear with large speed ratio and small tooth difference according to claim 4, characterized in that: At the slot, the planet sleeve of the planet carrier on the right side is connected to the input shaft via a central bearing on the inner side, and connected to the slot side wall on the outer side via a planet bearing; the two planetary discs are connected via a connecting rod to form an integrated structure.

6. A planetary reduction gear with large speed ratio and small tooth difference according to claim 1, characterized in that: The fixed inner gear ring is arranged on the right side of the output inner gear ring; the fixed inner gear ring is a hollow cylindrical structure, and a fixing hole is opened on the left end face, and the side wall of the fixing hole is provided with fixed teeth, and the fixed teeth maintain meshing transmission with the first planetary gear; and a fixing groove is opened in the center of the inner wall at the right end of the fixed inner gear ring, which is used to adapt to the rotatable installation of the input shaft and the planetary sleeve; the outer side wall of the fixed inner gear ring is also provided with a bearing step for adapting the installation of the connecting bearing.

7. A planetary reduction gear with large speed ratio and small tooth difference according to claim 6, characterized in that: The output inner gear ring includes a base plate, a ring body and a pillow block; the ring body is a columnar structure, and the inner diameter of the ring body is equal to the outer diameter of the fixed inner gear ring; the pillow block is an annular structure, and is fixedly arranged in the inner middle part of the ring body, and the inner wall of the pillow block is provided with output teeth, and the output teeth are meshed with the second planetary gear for transmission; the base plate is a solid plate, and a circular hole for adapting to the input shaft is opened at the left end, and a base groove is provided on the right side wall of the base plate for adapting to the rotatable installation of the input shaft and the planetary sleeve; wherein, the right end of the planetary shaft of the planetary frame distributed on the left side is connected to the planetary disk of the planetary frame distributed on the right side; the right end of the planetary shaft of the planetary frame distributed on the right side is connected to the planetary disk of the planetary frame distributed on the left side.

8. A planetary reduction gear with large speed ratio and small tooth difference according to claim 5 or 7, characterized in that: The number of teeth of the fixed teeth is equal to that of the output teeth.

9. A planetary reduction gear with large speed ratio and small tooth difference according to claim 5 or 7, characterized in that: There is a difference in the number of teeth between the fixed teeth and the output teeth.

10. A planetary reduction gear with large speed ratio and small tooth difference according to claim 5 or 7, characterized in that: An oil seal is also provided at the connection between the fixed inner gear ring and the output inner gear ring.

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