High-precision planet small-tooth-difference speed reducing mechanism

Abstract

The invention relates to the technical field of transmission devices, in particular to a high-precision planet small-tooth-difference speed reducing mechanism which comprises a fixed inner gear ring, an output inner gear ring, a center shaft, a sun gear and a planet carrier. The fixed inner gear ring and the output inner gear ring are rotationally connected through a bearing, tooth number difference exists between the fixed inner gear ring and the output inner gear ring, and the sun gear sleeves the middle of the center shaft and is integrally formed with the center shaft. The planet carrier comprises a planet plate, a cylinder and a fulcrum shaft; the planetary plate, the column body and the fulcrum shaft are of an integrally formed structure; a planet gear A and a planet gear B are mounted on a fulcrum shaft of the planet carrier, and at least one of the planet gear A and the planet gear B is in meshing transmission with the sun gear; meanwhile, the planet wheel A is in meshing transmission with the fixed inner gear ring; the planet gear B is in meshing transmission with the output inner gear ring, and a radius difference exists between the planet gear A and the planet gear B. A traditional eccentric shaft mechanism is omitted, manufacturing is easy, dynamic balance is good, noise is low, transmission precision is high, and the speed reduction requirement for the small space and the large speed ratio is met.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission devices, and in particular to a high-precision planetary small-tooth-difference speed reduction mechanism. 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 high-precision planetary small-tooth difference reduction mechanism that removes the eccentric shaft mechanism, is simple to manufacture, has good dynamic balance, low noise, high transmission accuracy, and can meet the requirements of small space and large speed ratio reduction.

[0005] The present invention adopts the following technical solutions to achieve the above purpose: A high-precision planetary small-tooth-difference speed reduction mechanism, comprising a fixed inner gear ring, an output inner gear ring, a central shaft, a sun gear, and a planet carrier; the fixed inner gear ring and the output inner gear ring are rotatably connected via a bearing, and the two are coaxially arranged, and there is a difference in the number of teeth between the fixed inner gear ring and the output inner gear ring; the central shaft passes through the fixed inner gear ring and the output inner gear ring, the sun gear is sleeved and installed in the middle of the central shaft, and the two are integrally formed; the planet carrier is divided into two groups symmetrically distributed on the left and right, and each group of the planet carrier includes a planet plate, a column, and a support shaft; The planetary plate is a circular ring structure, the support shaft is extended left and right on the planetary plate and is a plurality of evenly distributed rings, and the column is arranged on the planetary plate; the planetary plate, the column and the support shaft are an integrally formed structure, and the column and the central axis are connected and supported by bearings; planetary gears A and B are installed on the support shaft of the planetary frame, and at least one of the planetary gears A and B is kept meshing with the sun gear for transmission; at the same time, planetary gear A is meshing with a fixed inner gear ring for transmission; planetary gear B is meshing with an output inner gear ring for transmission, and there is a radius difference between the planetary gears A and B.

[0006] As a preferred technical solution: the fixed inner gear ring is installed on the left side of the output inner gear ring; the synchronized planetary gear A is arranged on the left side of the planetary gear B; the fixed inner gear ring includes a base and a ring table, and the base and the ring table are an integrally formed structure; the base is an annular opening structure, and the right inner wall is provided with teeth meshing with the planetary gear A; and the ring table is provided in the middle of the base, and the ring table is connected to the outer wall of the column supporting the planetary carrier through a bearing, and an oil seal is also provided at the connection between the ring table corresponding to the column and the central axis; the right outer wall of the base is provided with a mounting groove, which is used to maintain a rotational connection with the output inner gear ring through a bearing.

[0007] A further preferred technical solution: the output inner gear ring includes a main body and a shoulder; the cross-section of the main body is a concave structure, and the right side wall of the main body is a closed surface; the shoulder is an annular structure and is arranged on the inner wall of the middle part of the base, and teeth are provided on the shoulder to engage with the planetary gear B; the main body and the shoulder are an integrally formed structure; and the left side of the output inner gear ring forms a wrap around the fixed inner gear ring, so as to output torque to various places through the position of the outer periphery and end face of the output inner gear ring.

[0008] As a preferred technical solution: the fixed inner gear ring is installed on the right side of the output inner gear ring; the synchronized planetary gear A is arranged on the right side of the planetary gear B; at this time, the fixed inner gear ring is an overall concave structure, and teeth are arranged on the left inner wall to maintain meshing with the planetary gear A, the right side wall is a closed surface, and annular grooves are arranged on the left and right ends of the outer wall of the fixed inner gear ring for installing bearings to achieve a rotational connection with the output inner gear ring.

[0009] A further preferred technical solution: the output inner gear ring includes a cover plate, a ring body and a boss; the cover plate is circular and has a hole in the center that adapts to the central shaft, and an oil seal is also provided at the connection between the cover plate and the central shaft; the ring body is an annular structure and is arranged on the right side of the cover plate, the boss is annular and is arranged on the inner wall in the middle of the ring body, and teeth are arranged on the boss to maintain meshing transmission with the planetary gear B; the cover plate, the ring body and the boss are an integrally formed structure, and the right side of the output inner gear ring forms a wrap around the fixed inner gear ring, and the central shaft passes through the output inner gear ring and is arranged outward to output torque at one end.

[0010] A further preferred technical solution: the planetary gear A is installed on the support shaft of one of the planetary carriers, and one side of the planetary gear A is kept in meshing transmission with the sun gear, and the other side is kept in meshing transmission with the fixed inner gear ring; the planetary gear B is installed on the support shaft of the other planetary carrier, and one side of the planetary gear B is kept in meshing transmission with the sun gear, and the other side is kept in meshing transmission with the output inner gear ring, the radius of the planetary gear A is smaller than the radius of the planetary gear B; the number of teeth of the fixed inner gear ring is smaller than the number of teeth of the output inner gear ring; at the same time, the sun gear adopts a bipolar sun gear, which maintains meshing transmission with the sun gear A and the sun gear B respectively.

[0011] A further preferred technical solution: there is a gap between the planetary gear A and the planetary gear B; a connecting arm is provided between the two planetary plates so that the two planetary carriers form an integrated structure, and at this time the centers of the planetary gears A and B remain concentric.

[0012] A further preferred technical solution: there is an angle difference between the support shaft on the left planetary carrier and the support shaft on the right planetary carrier, and the centers of the planetary gear A and the planetary gear B are not concentric; at the same time, the support shaft on the left planetary carrier extends to the planetary plate of the right planetary carrier, and the support shaft on the right planetary carrier extends to the planetary plate of the left planetary carrier.

[0013] A further preferred technical solution is as follows: the planetary gear A and the planetary gear B are sleeved and installed on the same support shaft, and the planetary gear A, the planetary gear B and the support shaft are three groups that are matched and installed; the radius of the planetary gear A is smaller than the radius of the planetary gear B, and the two have the same number of teeth; the sun gear adopts a single-stage sun gear, which is meshed with the planetary gear A and has no contact with the planetary gear B; the fixed internal gear ring and the output internal gear ring have the same module and different numbers of teeth, and the planetary gear A and the fixed internal gear ring have the same normal module; the planetary gear B is any one of the positive displacement and negative displacement shape gears under the same module to match the meshing output internal gear ring.

[0014] A further preferred technical solution is as follows: the planetary gear A and the planetary gear B are sleeved and installed on the same support shaft, and the planetary gear A, the planetary gear B and the support shaft are three groups that are matched and installed; the radius of the planetary gear A is greater than the radius of the planetary gear B, and the two have the same number of teeth; the sun gear adopts a single-stage sun gear, which has no contact with the planetary gear A and is meshed with the planetary gear B; the fixed internal gear ring and the output internal gear ring have different modules and different numbers of teeth, at this time, the planetary gear A and the fixed internal gear ring, and the planetary gear B and the output internal gear ring are all meshed with the same normal module.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: when the sun gear in the present invention drives the planetary gear A and the planetary gear B at the same time, one of the two inner gear rings driven by the two planetary gears rotates faster and the other rotates slower, thus forming a rotation angle difference, thereby achieving the purpose of differential reduction; the design of this reduction mechanism can achieve a relatively large reduction ratio in a smaller volume space; the difference between the structure of this invention and the traditional small-tooth difference reducer is that the eccentric shaft mechanism that is difficult to manufacture is eliminated, the dynamic balance is improved, the manufacturing process is less difficult and the manufacturing cost is reduced; each running part can be supported and positioned by bearings, and has the advantage of high transmission accuracy; at the same time, it has the characteristics of multiple sets of planetary gears driven in parallel that are unique to planetary reducers, with large load bearing and high transmission power density; with the same transmission power, it has a lighter weight; compared with the same traditional planetary reducer, it has a larger speed ratio and lower cost; In addition, since the two planetary gears are integrated, the torques of the fixed inner gear ring and the output inner gear ring act on the two integrated planetary gears in opposite directions. The two forces counteract each other, and only the force of the difference in the radius of the inner gear ring is unbalanced. The difference is very small, which produces a nearly self-locking effect. For example, the fixed inner gear ring has 1 tooth and the output inner gear ring has 101 teeth. The unbalanced force is 1 / 50 of the radius difference between the two inner gear rings; so the part of the unbalanced force acting on the sun gear through the planetary gear is 1 / 50 of the output torque, and the braking torque of the sun gear is very small. This deceleration mechanism is applied to the hoisting equipment, which will greatly reduce the braking torque of the brake, reduce the equipment cost, and improve safety. The design of this deceleration mechanism can achieve a relatively large reduction ratio in a smaller volume space, and has a nearly fully self-locking performance. 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 is a three-dimensional diagram of a planet carrier according to Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of the overall structure of Embodiment 3 of the present invention; Figure 8 This is a working principle diagram of Embodiment 3 of the present invention; Fig. 9 is a three-dimensional diagram of a planet carrier according to Embodiment 3 of the present invention; Fig.10 It is a schematic diagram of the overall structure of Embodiment 4 of the present invention; Fig.11 This is a working principle diagram of Embodiment 4 of the present invention; Fig.12 This is a three-dimensional diagram of a planet carrier according to a fourth embodiment of the present invention.

[0018] In the figure: 1. fixed inner gear ring; 2. output inner gear ring; 3. central shaft; 4. sun gear; 5. planet carrier; 51. planet plate; 52. cylinder; 53. support shaft; 54. connecting arm; 6. bearing; 7. planet gear A; 8. planet gear B; 9. base; 10. ring platform; 11. oil seal; 12. mounting groove; 13. body; 14. shoulder; 15. closing surface; 16. cover plate; 17. ring body; 18. boss; 19. ring 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 As shown: A high-precision planetary small tooth difference reduction mechanism, including a fixed inner gear ring 1, an output inner gear ring 2, a central shaft 3, a sun gear 4, and a planet carrier 5. The minimum tooth number difference of the inner gear ring of the invention 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. Since there are only two inner gear rings and one planet carrier, the entire structure 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%. The fixed inner gear ring 1 and the output inner gear ring 2 are rotatably connected through a bearing 6, and the two are kept coaxially arranged, and an oil seal is also provided for sealing. Among them, the fixed inner gear ring: a gear ring with teeth inside, which plays the role of a fixed frame, and at the same time blocks the torque transmitted from the sun gear through the planetary gear, so that the planet carrier revolves around the sun gear. Output inner gear ring: A gear ring with teeth inside, which acts as an output component for transmitting the torque from the sun gear through the planetary gears. One of the two inner gear rings is a fixed end, and the other is an output end, and the two inner gear rings have different numbers of teeth. There is a difference in the number of teeth between the fixed inner gear ring 1 and the output inner gear ring 2. The central shaft 3 passes through the fixed inner gear ring 1 and the output inner gear ring 2, and the sun gear 4 is sleeved and installed in the middle of the central shaft 3, and the two are kept integrally formed. 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 they can be fixed inside the planetary carrier, which improves the running accuracy.

[0022] like Figure 1 As shown in FIG. 1 , the planet carriers 5 are arranged in two groups symmetrically on the left and right, and each group of the planet carriers 5 includes a planet plate 51, a column 52, a support shaft 53, and a connecting arm 54. Figure 3The structure shown. Specifically, the planetary plate and the column are mirror-symmetrically distributed structures. The planetary plate 51 is a circular ring structure, the support shaft 53 is arranged on the planetary plate 51 and is a plurality of evenly distributed rings, and the column 52 is arranged on the planetary plate 51; and the planetary plate 51, the column 52 and the support shaft 53 are an integrally formed structure. The planetary plates of the two planetary carriers 5 are connected by the connecting arm 54 to form an integral structure. Multiple sets of planetary gears can be installed on the planetary carrier, which serves as a retaining frame that fixes multiple planetary gears together and revolves around the sun gear.

[0023] Among them, Figure 1 As shown: the cylinder 52 is connected and supported by the central axis 3 through the bearing 6. A planetary gear A7 is installed on the support shaft 53 of one of the planetary carriers 5, and one side of the planetary gear A7 is kept meshing with the sun gear 4 and the other side is meshing with the fixed inner gear ring 1. The number of teeth of the fixed inner gear ring 1 is less than the number of teeth of the output inner gear ring 2. A planetary gear B8 is installed on the support shaft 53 of the other planetary carrier 5, and one side of the planetary gear B8 is kept meshing with the sun gear 4 and the other side is meshing with the output inner gear ring 2, and there is a radius difference between the planetary gear A7 and the planetary gear B8. Specifically, the radius of the planetary gear A7 is smaller than the radius of the planetary gear B8, and the centers of the two are not concentric. The present invention can realize a large speed ratio and small tooth difference reduction structure by simultaneously driving two planetary gears with different numbers of teeth on the same planetary carrier with a sun gear, plus a fixed inner gear ring and an output inner gear ring to form a primary reduction transmission chain. Two planetary gears with different radii are installed on the same planetary carrier (these planetary gears can be multiple sets in parallel), and the sun gear drives two planetary gears with different radii on an integrated planetary carrier at the same time. Driven by the sun gear, the two planetary gears drive the fixed inner ring and the output inner ring respectively. Unlike traditional planetary reducers, the planetary carrier can retain bearing steps at both ends, and the two ends of the planetary carrier can be fixed between the fixed inner ring and the output inner ring to achieve smooth operation. The minimum tooth number difference of the inner ring of the invention is 1 tooth, and the single-stage transmission ratio can reach more than 100, which can meet greater deceleration requirements in a smaller space. Since the eccentric shaft of the traditional small tooth difference reducer is eliminated, the manufacturing process is simplified and the dynamic balance of the structure is improved. Compared with the planetary reducer with the same speed ratio, the material saving is more than 20%, which effectively reduces the manufacturing cost.

[0024] like Figure 1As shown: As a preferred embodiment, in order to better adapt to the installation of the sun gear, planet carrier, etc., the fixed inner gear ring and the output inner gear ring are optimized: the fixed inner gear ring 1 is installed on the left side of the output inner gear ring 2; the synchronous planetary gear A7 is set on the left side of the planetary gear B8. The fixed inner gear ring 1 includes a base 9 and a ring 10, and the base 9 and the ring 10 are an integrally formed structure; the base 9 is an annular opening structure, and the right inner wall is provided with teeth to mesh with the planetary gear A7. The ring 10 is provided in the middle of the base 9, and the ring 10 is connected to the outer wall of the column 52 supporting the planetary carrier 5 through the bearing 6, and the ring 10 is also provided with an oil seal 11 at the connection between the column 52 and the central shaft 3, which serves as a seal to seal the rotating parts and prevent the lubricating oil from leaking. The right outer wall of the base 9 is provided with a mounting groove 12, which is used to maintain a rotational connection with the output inner gear ring 2 through the bearing 6. Among them, the output inner gear ring 2 includes a body 13 and a shoulder 14. The cross section of the body 13 is a concave structure, and the right side wall of the body 13 is a closed surface 15, which serves as the output end face. The outer peripheral side wall and one end face can be used as output connections, which can adapt to different installation requirements in various scenarios. The shoulder 14 is an annular structure and is arranged on the inner wall of the middle part of the base 9. The shoulder 14 is provided with teeth to mesh with the planetary gear B8; the body 13 and the shoulder 14 are an integrally formed structure. The left side of the output inner gear ring 2 forms a wrap around the fixed inner gear ring 1, so as to output torque to various places through the position of the outer periphery and end face of the output inner gear ring 2. 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.

[0025] Since the planetary gear and the inner gear ring are internal meshing transmission, the two meshing gear teeth are one concave tooth and one convex tooth, the curvature centers of the two teeth are in the same direction, and the curvature radius is close to 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 are in contact and force at the same time, so the load-bearing capacity is large. Smooth operation and low noise: Since 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 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 small, and the noise is reduced. Wide range of applications, the outer periphery of the output inner gear ring as the output component and one end face can be used as output connection, which can adapt to the different installation requirements of various scenarios, so the application range is wide, from small robot joints to large metallurgical mining machinery, engineering machinery, etc.

[0026] The specific working principle is as follows: Figure 1 and Figure 2As shown: First, the sun gear inputs high-speed transmission torque through the central shaft, and then the torque is transmitted from the sun gear to the planetary gear A installed on the planetary carrier. The sun gear meshes with the planetary gear A to drive the fixed inner ring gear. Since the fixed inner ring gear does not rotate, the torque drives the planetary carrier to revolve around the sun gear. At the same time, the sun gear also meshes with the planetary gear B to drive the output inner ring gear. Since the planetary gear A and the planetary gear B share an integrated planetary carrier, the radii of the planetary gear A and the planetary gear B are different. When the planetary carrier revolves around the sun gear, a rotation angle difference is formed between the fixed inner ring gear driven by the two planetary gears above and the output inner ring gear, that is, the speed difference. Specifically, the radius of the planetary gear A is smaller than the radius of the planetary gear B. Under the drive of the same sun gear, the speed of the planetary gear A is faster than that of the planetary gear B, and then the fixed inner ring gear meshed with it and the output inner ring gear have a relative speed difference, and the speed of the output inner ring gear is relatively slow, achieving the purpose of deceleration with a small tooth difference. Since the two inner ring gears are the deceleration principle realized by the difference in the number of teeth, the minimum difference in the number of teeth is 1, so the speed ratio is extremely large.

[0027] The solution of the present invention can be applied in a superimposed manner as required, and can also be superimposed with a traditional planetary small tooth difference reduction mechanism to achieve a larger reduction ratio requirement. At the same time, the technical solution of the present invention can also be used in combination with a sun gear tooth number difference mechanism (that is, two sun gears with a tooth number difference) to achieve a larger reduction ratio requirement.

[0028] Embodiment 2: A high-precision planetary small-tooth difference reduction mechanism. The technical solution of this embodiment is substantially similar to that of embodiment 1, except that: Figures 4 to 6 As shown: In order to better adapt to the installation of the sun gear, planet carrier, etc., the fixed inner gear ring and the output inner gear ring are optimized: the fixed inner gear ring 1 is installed on the right side of the output inner gear ring 2; the synchronized planetary gear A7 is set on the right side of the planetary gear B8. At this time, the fixed inner gear ring 1 is a concave structure as a whole, and the left inner wall is provided with teeth to keep meshing with the planetary gear A7, and the right wall is a closed surface 15. The left and right ends of the outer wall of the fixed inner gear ring 1 are provided with annular grooves 19 for installing bearings 6 to achieve rotational connection with the output inner gear ring 2. Among them, as Figure 3 As shown: the output inner gear ring 2 includes a cover plate 16, a ring body 17 and a boss 18. The cover plate 16 is circular, and a hole adapted to the central shaft 3 is opened in the center, and an oil seal 11 is also provided at the connection between the cover plate 16 and the central shaft 3; in order to maintain the sealing effect. The ring body 17 is an annular structure and is arranged on the right side of the cover plate 16. The boss 18 is annular and is arranged on the inner wall of the middle part of the ring body 17. The boss 18 is provided with teeth to maintain meshing transmission with the planetary gear B8; the cover plate 16, the ring body 17 and the boss 18 are an integrally formed structure, and the right side of the output inner gear ring 2 forms a wrapping for the fixed inner gear ring 1, and the central shaft 3 passes through the output inner gear ring 2 and is arranged outward to output torque at one end. This embodiment can be used as a supplement to the application scenario of embodiment 1, and the application field is flexible and wide.

[0029] like Figure 6 As shown: the preferred planetary frame structure of this embodiment: there is an angle difference between the support shaft 53 on the left planetary frame 5 and the support shaft 53 on the right planetary frame 5. At the same time, the support shaft 53 on the left planetary frame 5 extends to the planetary plate 51 of the right planetary frame 5, and the support shaft 53 on the right planetary frame 5 extends to the planetary plate 51 of the left planetary frame 5. In this way, the left end of the left support shaft is welded and fixed to the left planetary plate, and the right end is also welded and fixed to the right planetary plate after the planetary gear is installed; such a structure is more stable, and at the same time, the integrated structure of the two planetary frames is guaranteed, and the design of the connecting arm is omitted, and the overall use is more solid.

[0030] For specific working principle diagram, please refer to Figure 5 As shown, the fixed inner ring gear does not move, the central shaft drives the sun gear to rotate, and then the torque is transmitted from the sun gear to the planetary gear A installed on the planetary carrier. The sun gear meshes with the planetary gear A to drive the fixed inner ring gear. Since the fixed inner ring gear does not rotate, the torque drives the planetary carrier to revolve around the sun gear. At the same time, the sun gear also meshes with the planetary gear B to drive the output inner ring gear. Since the planetary gears A and B share an integrated planetary carrier, the radii of the planetary gears A and B are different. When the planetary carrier revolves around the sun gear, a rotation angle difference is formed between the fixed inner ring gear driven by the two planetary gears above and the output inner ring gear, that is, a speed difference. Specifically, the speed of the planetary gear A is faster than that of the planetary gear B, thereby achieving the purpose of speed reduction with a small tooth difference output.

[0031] Embodiment 3: A high-precision planetary small-tooth-difference speed reduction mechanism. The technical solution of this embodiment is substantially similar to that of embodiment 1, except that: in order to better achieve smooth transmission, simple manufacturing, large speed ratio and self-locking function, the meshing matching structure of the fixed inner gear ring and the output inner gear ring as well as the planet carrier and the sun gear is optimized and upgraded: Figures 7 to 9 As shown: the planetary gear A7 and the planetary gear B8 are sleeved and mounted on the same support shaft 53, see Fig. 9 The structure shown. Planetary gear A, planetary gear B and support shaft are three sets of matching installation. Among them, the radius of planetary gear A is smaller than the radius of planetary gear B, and the number of teeth of the two is the same. The sun gear 4 adopts a single-stage sun gear, which is meshed with planetary gear A and has no contact with planetary gear B. The fixed inner gear ring 1 and the output inner gear ring 2 have the same module but different numbers of teeth. At this time, the planetary gear A7 and the fixed inner gear ring 1 have the same normal module. Planetary gear B8 is any one of the positive displacement and negative displacement shape gears under the same module to match the meshing output inner gear ring 2.

[0032] The reduction mechanism of this embodiment is that the first-stage sun gear drives two sets of integrated planetary gears A and B with the same number of teeth on the integrated planetary carrier, and then the planetary gear A meshes with the fixed inner gear ring. Fig. 9 As shown: planetary gear B is meshed with the output inner gear ring. Planetary gear A and planetary gear B are two integral, coaxial and concentric gears, the two gears have the same number of teeth, and the two planetary gears are installed on the same planet carrier. The key point of this embodiment is to drive planetary gear A through a sun gear, and then drive two planetary gears B with the same number of teeth on the same planet carrier. At this time, planetary gear A and the fixed inner gear ring have the same normal module. Planetary gear B is any one of the positive displacement and negative displacement gears with the same module to match the meshing output inner gear ring diameter, plus a first-stage reduction transmission chain composed of a fixed inner gear ring and an output inner gear ring with different numbers of teeth, a large speed ratio and a small tooth difference reduction structure can be achieved.

[0033] Two planetary gears with the same number of teeth are installed on the same planetary carrier. Planetary gear A and planetary gear B are coaxial and concentric one-piece gears. When one of the planetary gears is of normal modulus, the other planetary gear is of the same modulus and is in a positive or negative displacement shape; the two planetary gears can also be of the same number of teeth but different modulus, so as to match the two inner gear rings with different numbers of teeth meshing with them. The number of teeth of the fixed inner gear ring matches that of planetary gear A. The number of teeth of the output inner gear ring has a difference with that of the fixed inner gear ring, which matches the number of teeth of planetary gear B. In this way, when the sun gear drives planetary gear A or drives planetary gear B (the sun gear can drive any one of the two sets of planetary gears), the planetary carrier revolves around the sun gear while the two planetary gears rotate. The two inner gear rings driven by the two planetary gears have one with a fast rotation speed and the other with a slow rotation speed, which forms a rotation angle difference with different rotation speeds, thereby achieving the purpose of differential deceleration. It is also possible that the two planetary gears have the same module but different numbers of teeth, and the two inner ring gears have the same number of teeth and the same module, and one of them is a positive displacement or negative displacement shape with the same module to match the respective meshing requirements.

[0034] In addition, since the two planetary gears are integrated, the torque directions of the fixed inner gear ring 1 and the output inner gear ring 2 are exactly opposite to each other and act on the two integrated planetary gears. The two forces offset each other, and only the force of the difference in the radius of the inner gear ring is unbalanced. The difference is very small, which produces a nearly self-locking effect. For example, the number of teeth of the fixed inner gear ring 1 is 100 and the number of teeth of the output inner gear ring 2 is 101. The unbalanced force is 1 / 50 of the radius difference between the two inner gear rings. Therefore, the part of the unbalanced force acting on the sun gear through the planetary gear is 1 / 50 of the output torque, and the braking torque of the sun gear is very small. This reduction mechanism is applied to the hoisting equipment, which will greatly reduce the braking torque of the brake, reduce the equipment cost, and improve safety. The design of this reduction mechanism can achieve a relatively large reduction ratio in a smaller volume space, and has a nearly fully self-locking performance.

[0035] Embodiment 4: A high-precision planetary small-tooth-difference speed reduction mechanism. The technical solution of this embodiment is substantially similar to that of embodiment 2, except that: in order to better achieve smooth transmission, simple manufacturing, large speed ratio and self-locking function, the meshing matching structure of the fixed inner gear ring and the output inner gear ring as well as the planet carrier and the sun gear is optimized and upgraded: Figures 10 to 12 As shown: the planetary gear A7 and the planetary gear B8 are sleeved and mounted on the same support shaft 53, and the planetary gear A, the planetary gear B, and the support shaft are three sets of matching installations; the structure of this part of the planetary carrier is as shown Fig.12 The structure shown. The radius of planetary gear A7 is greater than that of planetary gear B8, and the two have the same number of teeth; the sun gear 4 adopts a single-stage sun gear, which has no contact with planetary gear A and meshes with planetary gear B. The bearings at both ends of the sun gear can be fixed on the planetary carrier to maintain the concentricity with the planetary gear during operation, and are not affected by the concentricity of other components, and the transmission accuracy is high. The fixed inner gear ring 1 and the output inner gear ring 2 have different modules and different numbers of teeth. At this time, the planetary gear A and the fixed inner gear ring, and the planetary gear B and the output inner gear ring are all meshed with the same normal module.

[0036] like Fig.12 As shown: The reduction mechanism of this embodiment is driven by a primary sun gear to drive two sets of integrated planetary gears A and B with the same number of teeth on the integrated planetary carrier, and then the planetary gear A meshes with the fixed inner gear ring. Planetary gear B meshes with the output inner gear ring. Planetary gear A and planetary gear B are two integrated, concentric and coaxial gears with the same number of teeth, and the two planetary gears are installed on the same planetary carrier.

[0037] The number of teeth of the fixed inner gear ring matches that of planetary gear A. The number of teeth of the output inner gear ring differs from that of the fixed inner gear ring, and matches the number of teeth of planetary gear B. In this way, when the sun gear drives planetary gear B, the planet carrier revolves around the sun gear while the two planetary gears rotate. The two inner gear rings driven by the two planetary gears have one with a fast rotation speed and the other with a slow rotation speed, which forms a rotation angle difference with different rotation speeds, thereby achieving the purpose of differential reduction. One of the two inner gear rings is a fixed end, and the other is an output end. The forces of the two inner gear rings act relatively on the planetary gears, and have a nearly balanced self-locking function. The purpose of this embodiment is to achieve a new transmission device designed to achieve a larger reduction ratio requirement through a first-stage reduction of a sun gear and a planet carrier within an effective spatial volume. It also achieves the effects of high transmission power density, high precision, and nearly balanced self-locking of output torque and fixed torque.

[0038] 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 high-precision planetary small-tooth-difference speed reduction mechanism, characterized in that: The invention comprises a fixed inner gear ring (1), an output inner gear ring (2), a central shaft (3), a sun gear (4), and a planet carrier (5); the fixed inner gear ring (1) and the output inner gear ring (2) are rotationally connected via a bearing (6), and the two are arranged coaxially, and there is a difference in the number of teeth between the fixed inner gear ring (1) and the output inner gear ring (2); the central shaft (3) passes through the fixed inner gear ring (1) and the output inner gear ring (2), and the sun gear (4) is sleeved and installed in the middle of the central shaft (3), and the two are integrally formed; the planet carrier (5) is composed of two groups of left-right symmetrically distributed planet carriers, and each group of the planet carriers (5) comprises a planet plate (51), a column (52), and a support shaft (53); the planet plate (51) is a circular ring structure, and the sun gear (4) is sleeved and installed in the middle of the central shaft (3), and the two are integrally formed; The support shaft (53) is arranged on the planetary plate (51) in a manner extending left and right and is evenly distributed in a ring shape. The column (52) is arranged on the planetary plate (51). The planetary plate (51), the column (52) and the support shaft (53) are an integrally formed structure. The column (52) and the central axis (3) are connected and supported by a bearing (6). A planetary gear A (7) and a planetary gear B (8) are mounted on the support shaft (53) of the planetary carrier (5), and at least one of the planetary gear A (7) and the planetary gear B (8) is kept meshing with the sun gear (4) for transmission. At the same time, the planetary gear A (7) is meshing with the fixed inner gear ring (1) for transmission. The planetary gear B (8) is meshing with the output inner gear ring (2) for transmission, and there is a radius difference between the planetary gear A (7) and the planetary gear B (8).

2. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 1, characterized in that: The fixed inner gear ring (1) is mounted on the left side of the output inner gear ring (2); the synchronous planetary gear A (7) is arranged on the left side of the planetary gear B (8); the fixed inner gear ring (1) comprises a base (9) and a ring platform (10), the base (9) and the ring platform (10) being an integrally formed structure; the base (9) is an annular open structure, and teeth are arranged on the right inner wall to mesh with the planetary gear A (7); the ring platform (10) is arranged in the middle of the base (9), the ring platform (10) is connected to the outer wall of the column (52) supporting the planetary carrier (5) through a bearing (6), and an oil seal (11) is also arranged at the connection between the column (52) and the central shaft (3) of the ring platform (10); the right outer wall of the base (9) is provided with a mounting groove (12) for maintaining a rotational connection with the output inner gear ring (2) through the bearing (6).

3. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 2, characterized in that: The output inner gear ring (2) comprises a body (13) and a shoulder (14); the cross section of the body (13) is a concave structure, and the right side wall of the body (13) is a closed surface (15); the shoulder (14) is an annular structure and is arranged on the inner wall of the middle part of the base (9), and teeth are provided on the shoulder (14) to mesh with the planetary gear B (8); the body (13) and the shoulder (14) are an integrally formed structure; and the left side of the output inner gear ring (2) forms a wrap around the fixed inner gear ring (1), so as to output torque to various places through the position of the outer periphery and end surface of the output inner gear ring (2).

4. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 1, characterized in that: The fixed inner gear ring (1) is mounted on the right side of the output inner gear ring (2); the synchronous planetary gear A (7) is arranged on the right side of the planetary gear B (8); at this time, the fixed inner gear ring (1) is an overall concave structure, and teeth are arranged on the left inner wall to maintain meshing with the planetary gear A (7), and the right wall is a closed surface (15). The left and right ends of the outer wall of the fixed inner gear ring (1) are both provided with annular grooves (19) for mounting bearings (6) to achieve rotational connection with the output inner gear ring (2).

5. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 4, characterized in that: The output inner gear ring (2) comprises a cover plate (16), a ring body (17) and a boss (18); the cover plate (16) is circular and has a hole at the center thereof adapted to the central shaft (3), and an oil seal (11) is also provided at the connection between the cover plate (16) and the central shaft (3); the ring body (17) is an annular structure and is arranged on the right side of the cover plate (16); the boss (18) is annular and is arranged on the inner wall of the middle part of the ring body (17); teeth are provided on the boss (18) to maintain meshing transmission with the planetary gear B (8); the cover plate (16), the ring body (17) and the boss (18) are an integrally formed structure, and the right side of the output inner gear ring (2) forms a wrap around the fixed inner gear ring (1); the central shaft (3) passes through the output inner gear ring (2) and is arranged outwardly to output torque at one end.

6. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in any one of claims 3 or 5, characterized in that: The planetary gear A (7) is mounted on the support shaft (53) of one of the planetary carriers (5), and one side of the planetary gear A (7) is kept meshing with the sun gear (4) for transmission, and the other side is meshing with the fixed inner gear ring (1) for transmission; the planetary gear B (8) is mounted on the support shaft (53) of the other planetary carrier (5), and one side of the planetary gear B (8) is kept meshing with the sun gear (4) for transmission, and the other side is meshing with the output inner gear ring (2) for transmission; the radius of the planetary gear A (7) is smaller than the radius of the planetary gear B (8); the number of teeth of the fixed inner gear ring (1) is smaller than the number of teeth of the output inner gear ring (2); and the sun gear adopts a bipolar sun gear, which is respectively meshing with the sun gear A and the sun gear B.

7. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 6, characterized in that: There is a gap between the planetary gear A (7) and the planetary gear B (8); a connecting arm (54) is provided between the two planetary plates (51), so that the two planetary carriers form an integrated structure, and at this time, the centers of the planetary gear A and the planetary gear B remain concentric.

8. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 6, characterized in that: There is an angle difference between the support shaft (53) on the left planetary frame (5) and the support shaft (53) on the right planetary frame (5), and the centers of the planetary gear A and the planetary gear B are not concentric; at the same time, the support shaft (53) on the left planetary frame extends to the planetary plate (51) of the right planetary frame, and the support shaft (53) on the right planetary frame extends to the planetary plate (51) of the left planetary frame.

9. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 3, characterized in that: The planetary gear A (7) and the planetary gear B (8) are sleeved and mounted on the same support shaft (53), and the planetary gear A, the planetary gear B and the support shaft are three sets of matching installations; the radius of the planetary gear A (7) is smaller than the radius of the planetary gear B (8), and the two have the same number of teeth; the sun gear (4) is a single-stage sun gear, meshing with the planetary gear A (7) and having no contact with the planetary gear B (8); the fixed inner gear ring (1) and the output inner gear ring (2) have the same module but different numbers of teeth, and at this time, the planetary gear A (7) and the fixed inner gear ring (1) have the same normal module; the planetary gear B (8) is any one of a positive displacement gear and a negative displacement gear with the same module to match the meshing output inner gear ring (2).

10. A high-precision planetary small-tooth-difference speed reduction mechanism as claimed in claim 5, characterized in that: The planetary gear A (7) and the planetary gear B (8) are sleeved and mounted on the same support shaft (53), and the planetary gear A, the planetary gear B and the support shaft are three sets of matching installations; the radius of the planetary gear A (7) is greater than the radius of the planetary gear B (8), and the two have the same number of teeth; the sun gear (4) is a single-stage sun gear, which is non-contacting with the planetary gear A (7) and meshing with the planetary gear B (8); the fixed inner gear ring (1) and the output inner gear ring (2) have different modules and different numbers of teeth, and at this time, the planetary gear A (7) and the fixed inner gear ring (1), and the planetary gear B (8) and the output inner gear ring (2) all have the same normal module for meshing.

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