Double-composite cylindrical planetary gear transmission mechanism

Abstract

The invention relates to the field of cylindrical planetary gear transmission, in particular to a double-composite cylindrical planetary gear transmission mechanism which is characterized in that an inner gear ring is arranged on the inner side face of a shell, a center wheel shaft is arranged in the center of the interior of the shell and sleeved with a center wheel, and a planet carrier is arranged in the shell; three inner planet wheel shafts and three outer planet wheel shafts are installed on the planet carrier, the outer side faces of the inner planet wheel shafts are connected with inner planet wheels through inner planet wheel bearings, and the outer side faces of the outer planet wheel shafts are connected with outer planet wheels through outer planet wheel bearings; each planet wheel is stressed at three point positions and can bear larger load, stress and power division are more balanced, and it is ensured that the gear set can stably and reliably transmit power under the complex working condition; the six planet wheels are arranged in an inner circle and an outer circle around the center wheel, the diameter of the planet wheels is reduced, and the problem that adjacent planet wheels interfere with each other when the transmission ratio of an original planet mechanism is large is solved.

Description

Technical Field

[0001] The present invention relates to the field of cylindrical planetary gear transmissions, and particularly to a double composite cylindrical planetary gear transmission mechanism. Background Art

[0002] Planetary gear transmission mechanisms, with their advantages of compact structure, large transmission ratio, high transmission efficiency, etc., are widely used in many fields such as automobiles, aerospace, and mechanical manufacturing. With the development of mechatronic power transmission technology and the progress of the robot equipment industry, higher and higher requirements have been put forward for the transmission ratio, vibration noise, and volume power density of planetary gears. There are many contradictions in the comprehensive design of the three indicators of strength, efficiency, and transmission ratio of planetary gear transmission devices. On the one hand, when the gears rotate at high speed, tooth surface collisions inevitably cause impacts, increasing dynamic loads and vibration noise. At the same time, problems such as uneven power splitting of planetary gears and difficult-to-eliminate eccentric loads have long existed. On the other hand, achieving a large transmission ratio, low power consumption, and high efficiency in a small space has always troubled the further development of planetary gear transmission technology.

[0003] Facing increasingly complex and changeable working conditions, it is more difficult to improve the transmission performance of gears. Although there are also attempts in the prior art to alleviate the above problems by optimizing gear machining accuracy, replacing gear materials, etc., the effects are limited, and it is difficult to meet the strict requirements in many aspects such as high-speed precision, small volume, large transmission ratio, high transmission efficiency, and low vibration noise at the same time. Therefore, there is an urgent need for a new planetary gear structure design to break through these technical bottlenecks. Summary of the Invention

[0004] The present application aims to provide a double composite cylindrical planetary gear transmission mechanism to solve the deficiencies of existing planetary gears in terms of dynamic comprehensive performance indicators such as transmission accuracy, transmission ratio, transmission efficiency, vibration, and noise, and can effectively solve the problems in the background art.

[0005] To achieve the above object, the present application provides the following technical solution: A double composite cylindrical planetary gear transmission device includes a housing. The inner side surface of the housing is provided with an internal gear ring. The central part inside the housing is provided with a central gear shaft. A central gear is sleeved on the central gear shaft. A planetary carrier is provided inside the housing. Three internal planetary gear shafts and three external planetary gear shafts are installed on the planetary carrier. The outer side surface of the internal planetary gear shaft is connected with an internal planetary gear through an internal planetary gear bearing. The outer side surface of the external planetary gear shaft is connected with an external planetary gear through an external planetary gear bearing.

[0006] The three internal planetary gears are annularly and evenly distributed around the central gear. The internal planetary gears mesh with the central gear. The three planetary gears are annularly and evenly distributed on the inner side edge of the internal gear ring. The planetary gears mesh with the internal gear ring. Each planetary gear meshes with the two adjacent internal planetary gears.

[0007] Preferably, the number of planet gears in the planetary gear system is six.

[0008] Preferably, the number of planet gears is not limited to six, but any number of internal and external planet gears that can achieve a large transmission ratio.

[0009] Preferably, the outer planet gear bearing and the inner planet gear bearing are preferably needle roller bearings.

[0010] Preferably, the central gear shaft and the central gear are connected by a key.

[0011] Preferably, the central gear shaft and the central gear are integrally designed in the form of a shaft gear.

[0012] Preferably, the outer shell is fixedly installed with the internal gear ring, and the planet carrier is used as a rotating part.

[0013] Preferably, the planet carrier is fixed, and the outer shell and the internal gear ring are used as rotating parts.

[0014] Compared with the prior art, the beneficial effects of this application are as follows:

[0015] 1. Each planet gear is stressed at three points, can bear a greater load, and the stress and power shunting are more balanced, ensuring that the gear set can stably and reliably transmit power under complex working conditions;

[0016] 2. Six planet gears are arranged in two inner and outer circles around the central gear, reducing the diameter of the planet gears and avoiding the problem of interference between adjacent planet gears when the transmission ratio of the original planetary mechanism is relatively large; at the same time, there is more room for optimization design in the selection of the number of teeth and modification coefficients of the central gear, planet gears and internal gears to achieve a larger transmission ratio;

[0017] 3. Through the combination of two groups of internal and external planet gears in this invention, the planetary gear transmission mechanism achieves a larger transmission ratio, and at the same time, the performance optimization in terms of load-bearing capacity, vibration reduction and noise reduction, and transmission accuracy is improved, providing a new solution for the field of planetary gear transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of this application.

[0019] In the figure: 1 - outer planet gear shaft; 2 - outer planet gear bearing; 3 - outer planet gear; 4 - inner planet gear shaft; 5 - inner planet gear bearing; 6 - inner planet gear; 7 - internal gear ring; 8 - central gear; 9 - central gear shaft; 10 - planet carrier; 11 - outer shell. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0021] In the description of the present application, when a certain feature is referred to as "arranged", "fixed", or "connected" to another feature, it can be directly arranged, fixed, or connected to another feature, or indirectly arranged, fixed, or connected to another feature.

[0022] Please refer to Figure 1 , the present application provides the following technical solutions:

[0023] Embodiment 1:

[0024] A double compound cylindrical planetary gear transmission device includes a housing 11. An internal gear ring 7 is provided on the inner side surface of the housing 11. A central gear shaft 9 is provided in the center of the housing 11. A central gear 8 is sleeved on the central gear shaft 9. A planet carrier 10 is provided inside the housing 11. Three internal planet gear shafts 4 and three external planet gear shafts 1 are installed on the planet carrier 10. An internal planet gear 6 is connected to the outer side surface of the internal planet gear shaft 4 through an internal planet gear bearing 5. An external planet gear 3 is connected to the outer side surface of the external planet gear shaft 1 through an external planet gear bearing 2.

[0025] Specifically, the internal and external planet gear shafts are arranged on both sides of the planet carrier 10. With the double meshing layout, the overall volume of the device is significantly reduced, which is suitable for the precision machinery field with strict space requirements.

[0026] Through the division of labor and cooperation of the internal and external planet gear groups, the internal planet gear 6 meshes with the central gear 8 to transmit the main torque, and the external planet gear 3 meshes with the internal gear ring 7 to share the radial load, significantly improving the overall load-bearing capacity.

[0027] The modular installation method of the planet carrier 10 and the gear shafts simplifies the assembly process, facilitates maintenance and replacement of components, and reduces the use cost.

[0028] The three internal planet gears 6 are evenly distributed in a ring around the central gear 8. The internal planet gears 6 mesh with the central gear 8. The three planet gears 3 are evenly distributed in a ring on the inner side edge of the internal gear ring 7. The planet gears 3 mesh with the internal gear ring 7. Each planet gear 3 meshes with the two adjacent internal planet gears 6.

[0029] Specifically, the inner planet gear 6 meshes with the central gear 8 to form the first-stage drive, and the outer planet gear 3 meshes with the internal gear ring 7 to form the second-stage drive. The double-mesh design makes the power split more uniform and reduces the risk of eccentric load. Each outer planet gear meshes with two inner planet gears simultaneously, forming a force transmission path with multiple points of contact, effectively suppressing vibration and shock, and reducing the operating noise. The multi-mesh point design improves the reliability of the system. Even if a single gear is locally worn, it can still maintain normal operation through other meshing points, extending the service life.

[0030] Further, the number of planet gears in the planetary gear system is six.

[0031] Specifically, the six-planet gear layout superimposes the transmission ratio through double meshing, enabling a larger reduction ratio to be achieved within a limited space, meeting the requirements of high-precision scenarios such as industrial robotic arms.

[0032] Further, the number of planet gears is not limited to six, but any number of inner and outer planet gears that can achieve a large transmission ratio.

[0033] Further, the outer planet gear bearing 2 and the inner planet gear bearing 5 are preferably needle roller bearings.

[0034] Specifically, the needle roller bearing has a small radial cross-section and a high load-carrying capacity, which can support the planet gear to remain stable during high-speed rotation and is suitable for high-speed scenarios such as direct drive by motors.

[0035] Further, the central gear shaft 9 and the central gear 8 are connected by a key.

[0036] Further, the central gear shaft 9 and the central gear 8 are integrally designed in the form of a shaft gear.

[0037] Further, the housing 11 is fixedly installed with the internal gear ring 7, and the planet carrier 10 is a rotating part.

[0038] Further, the planet carrier 10 is fixed, and the housing 11 and the internal gear ring 7 are rotating parts.

[0039] Embodiment 2

[0040] The main difference between Embodiment 2 and Embodiment 1 lies in the connection method between the central gear shaft 9 and the central gear 8.

[0041] A double-compound cylindrical planetary gear transmission device includes a housing 11. The inner side of the housing 11 is provided with an internal gear ring 7. The central part inside the housing 11 is provided with a central gear shaft 9. A central gear 8 is sleeved on the central gear shaft 9. The inside of the housing 11 is provided with a planet carrier 10. Three inner planet gear shafts 4 and three outer planet gear shafts 1 are installed on the planet carrier 10. The outer side of the inner planet gear shaft 4 is connected with an inner planet gear 6 through an inner planet gear bearing 5. The outer side of the outer planet gear shaft 1 is connected with a planet gear 3 through an outer planet gear bearing 2.

[0042] Three inner planet gears 6 are evenly distributed around the central gear 8 in a ring shape. The inner planet gears 6 mesh with the central gear 8. Three planet gears 3 are evenly distributed around the inner side edge of the internal gear ring 7 in a ring shape. The planet gears 3 mesh with the internal gear ring 7. Each planet gear 3 meshes with two adjacent inner planet gears 6.

[0043] Furthermore, the number of planet gears in the planetary gear system is six.

[0044] Furthermore, the outer planet gear bearings 2 and the inner planet gear bearings 5 are preferably needle bearings.

[0045] Furthermore, the central gear shaft 9 and the central gear 8 are integrally designed in the form of a shaft gear.

[0046] Furthermore, the housing 11 is fixedly installed with the internal gear ring 7, and the planet carrier 10 is used as a rotating part.

[0047] Embodiment 3:

[0048] The difference between Embodiment 3 and Embodiments 1 and 2 lies in the rotating part and the fixed part.

[0049] A double compound cylindrical planetary gear transmission device includes a housing 11. The inner side of the housing 11 is provided with an internal gear ring 7. The central part inside the housing 11 is provided with a central gear shaft 9. A central gear 8 is sleeved on the central gear shaft 9. The inside of the housing 11 is provided with a planet carrier 10. Three inner planet gear shafts 4 and three outer planet gear shafts 1 are installed on the planet carrier 10. The outer side of the inner planet gear shaft 4 is connected with an inner planet gear 6 through an inner planet gear bearing 5. The outer side of the outer planet gear shaft 1 is connected with a planet gear 3 through an outer planet gear bearing 2.

[0050] Three inner planet gears 6 are evenly distributed around the central gear 8 in a ring shape. The inner planet gears 6 mesh with the central gear 8. Three planet gears 3 are evenly distributed around the inner side edge of the internal gear ring 7 in a ring shape. The planet gears 3 mesh with the internal gear ring 7. Each planet gear 3 meshes with two adjacent inner planet gears 6.

[0051] Furthermore, the number of planet gears is not limited to six, but any number of inner and outer planet gears that can achieve a large transmission ratio.

[0052] Furthermore, the outer planet gear bearings 2 and the inner planet gear bearings 5 are preferably needle bearings.

[0053] Furthermore, the central gear shaft 9 and the central gear 8 are connected by a key.

[0054] Furthermore, the planet carrier 10 is fixed, and the housing 11 and the internal gear ring 7 are used as rotating parts.

[0055] In use: The inner planet gears 6 and the inner planet gear bearings 5 are evenly distributed in three directions on the inner circumference of the central gear 8 and are mutually 60 degrees apart from each other when cooperating with the central gear. The outer planet gears 3 and the outer planet gear bearings 2 are evenly distributed in three directions on the outer circumference of the central gear 8 and are staggered 60 degrees from the inner circumference planet gears. The inner planet gears 6 cooperate with the two outer planet gears 3 while cooperating with the central gear 8. The outer planet gears 3 cooperate with the inner ring gear 7 while cooperating with the inner planet gears 6, so that the force application points of each planet gear are the same, in order to achieve the purpose of balanced force and power splitting; The central gear 8 and the central gear shaft 9 are integrally installed. As Figure 1 shown, when the central gear drives the inner planet gear 6 to rotate, the outer planet gear 3 rotates driven by the inner planet gear 6. The outer planet gear 3 cooperates with the inner ring gear 7 to drive the planet carrier 10 to rotate, thereby achieving the purpose of a large transmission ratio.

[0056] The working process of this transmission device: The integrated central gear 8 and the central gear shaft 9, as the power input end, drive the three inner planet gears 6 to rotate. The three inner planet gears 6 drive the three outer planet gears 3 to rotate. The three outer planet gears 3 roll in the inner ring gear 7, and the planet gears drive the planet carrier 10 to output power.

[0057] Although the embodiments of the present application have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A double compound cylindrical planetary gear transmission device, characterized in that: It includes a housing (11). An internal gear ring (7) is provided on the inner side surface of the housing (11). A central wheel shaft (9) is provided at the center inside the housing (11). A central wheel (8) is sleeved on the central wheel shaft (9). A planet carrier (10) is provided inside the housing (11). Three internal planet wheel shafts (4) and three external planet wheel shafts (1) are installed on the planet carrier (10). An internal planet wheel (6) is connected to the outer side surface of the internal planet wheel shaft (4) through an internal planet wheel bearing (5). An external planet wheel (3) is connected to the outer side surface of the external planet wheel shaft (1) through an external planet wheel bearing (2). The three internal planet wheels (6) are evenly distributed annularly around the central wheel (8). The internal planet wheels (6) mesh with the central wheel (8). The three planet wheels (3) are evenly distributed annularly on the inner side edge of the internal gear ring (7). The planet wheels (3) mesh with the internal gear ring (7). Each planet wheel (3) meshes with the two adjacent internal planet wheels (6).

2. The double compound cylindrical planetary gear transmission device according to claim 1, characterized in that: The number of planet wheels in the planetary gear system is six.

3. A double compound cylindrical planetary gear transmission device according to claim 1, characterized in that: The number of planet wheels is not limited to six, but any number of internal and external planet wheels that can achieve the purpose of a large transmission ratio.

4. A double compound cylindrical planetary gear transmission device according to claim 1, characterized in that: The external planet wheel bearing (2) and the internal planet wheel bearing (5) are preferably needle bearings.

5. A double compound cylindrical planetary gear transmission device according to claim 1, characterized in that: The central wheel shaft (9) and the central wheel (8) are connected by a key.

6. A double composite cylindrical planetary gear transmission device according to claim 1, characterized in that: The central wheel shaft (9) and the central wheel (8) are integrally designed in the form of a shaft gear.

7. A double compound cylindrical planetary gear transmission device according to claim 1, characterized in that: The housing (11) and the internal gear ring (7) are fixedly installed, and the planet carrier (10) is a rotating part.

8. A double compound cylindrical planetary gear transmission device according to claim 1, characterized in that: The planet carrier (10) is fixed, and the housing (11) and the internal gear ring (7) are rotating parts.

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