Planetary reduction gearbox
By using an integrated planetary carrier and sun gear design, combined with the use of web plates and needle roller bearings, the problem of insufficient rigidity and tooth breakage in planetary gearboxes under high loads has been solved, achieving higher torque transmission and simplifying the assembly process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHANGZHOU MOLAN MECHANICAL & ELECTRICAL TECHNOLOGY CO LTD
- Filing Date
- 2026-03-31
- Publication Date
- 2026-05-29
AI Technical Summary
Existing planetary gearboxes are prone to gear breakage and cracking when transmitting high torque, and insufficient rigidity can lead to jamming, making it impossible to effectively transmit high loads.
It adopts an integrated planetary carrier and sun gear structure, with the inner bore of the planetary gears having an added web structure. Combined with a three-stage transmission design, the rigidity of the planetary gears is enhanced, and the transmission structure is optimized through the combined use of needle roller bearings and bearings.
This improved the rigidity and torque transmission capacity of the gearbox, avoided gear breakage and cracking problems, and reduced assembly complexity and labor costs.
Smart Images
Figure CN122107075A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a planetary gearbox, belonging to the field of gearbox technology. Background Technology
[0002] With market demand, planetary gearboxes require more compact structures and higher torque transmission capabilities. For miniature gearboxes, the planetary carrier and sun gear are typically fixed using interference fits or welding. However, this structure is only suitable for low to medium load transmission. When transmitting high torque, slippage and gearbox failure are likely to occur. Common failure modes include tooth breakage and internal bore cracking of the planetary gears; tooth breakage and cracking of the internal gear ring; and insufficient rigidity of the planetary carrier, causing planetary gear tilting and gearbox jamming. Therefore, there is an urgent need to propose a gearbox structure that can effectively solve the problems of tooth breakage and insufficient rigidity, enabling the gearbox to transmit higher torque. Summary of the Invention
[0003] The purpose of this invention is to overcome the problems of tooth breakage and insufficient rigidity in the prior art, and to provide a planetary gearbox that can transmit higher torque. To achieve the above objectives / to solve the above technical problems, the present invention is implemented using the following technical solution: A planetary gearbox includes a primary transmission, a secondary transmission, and a tertiary transmission; The primary transmission includes a planetary gear C located on one side of the planet carrier and meshing with an external transmission mechanism; The secondary transmission includes a sun gear A, a sun gear B located at the center of the other side of the planet carrier, and a planet gear B meshing with the sun gear B. The planet gear B is connected to the sun gear A. The three-stage transmission includes planetary gear A, the output end of the sun gear A meshes with planetary gear A, and planetary gear A meshes with an output shaft; Planetary gear C and planetary gear B are externally meshed with internal gear ring B, planetary gear A is externally meshed with internal gear ring A, and at least one end and / or the middle of the inner hole of planetary gear A is provided with a web structure.
[0004] Optionally, a planet carrier cover plate is provided between the sun gear B and the planet carrier.
[0005] Optionally, one end of the output shaft is provided with a bearing A via a bearing housing, and the other end of the output shaft is provided with a bearing B, which is installed inside the internal gear ring B; one end of the internal gear ring B is connected to the internal gear ring A, and the other end is connected to a connecting flange.
[0006] Optionally, the planetary gear B is mounted on a needle roller bearing, the needle roller bearing is mounted on the planetary gear pin B, and the planetary gear pin B is fixedly connected to the sun gear A.
[0007] Optionally, the planetary gear C is sleeved on the needle roller bearing, the needle roller bearing is sleeved on the planetary gear pin C, and the planetary gear pin C is fixedly connected to the planet carrier.
[0008] Optionally, the planetary gear A is sleeved on the needle roller, and the needle roller is installed in the inner hole of the planetary gear A, and the two can rotate relative to each other.
[0009] Optionally, the web structure is integral with planetary gear A or disposed at at least one end of planetary gear A via a cover plate.
[0010] Optionally, the transmission mechanism includes a motor, the output end of which is provided with a gear connecting sleeve, the gear connecting sleeve is provided with a motor gear, and the motor gear meshes with a planetary gear C.
[0011] Optionally, the output shaft includes a planetary carrier, and the two are integrated.
[0012] Optionally, the sun gear A includes a planet carrier for mounting the planet gear B, and the planet carrier is integral with the sun gear A.
[0013] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: 1. The output shaft of the gearbox of the present invention is an integrated planetary carrier, which simultaneously serves the functions of outputting torque, mounting and supporting planetary gears, and enhancing the rigidity of the planetary carrier with a planetary carrier cover plate; this integrated planetary carrier has the advantage of transmitting higher loads; 2. The present invention adds one or more web plates to the inner hole of planetary gear A, which greatly improves the rigidity and strength of the planetary gear and effectively solves the problem of tooth breakage or cracking of the planetary gear under heavy load; 3. The integrated sun gear A of this invention integrates the sun gear and the planet carrier into one piece. Compared with the conventional pin + welding method, it can transmit higher loads and eliminates assembly and welding steps during assembly, saving labor costs. Attached Figure Description
[0014] Figure 1 The figure shown is a cross-sectional view of the overall structure of the gearbox of the present invention; Figure 2 The diagram shown is a schematic of the assembly structure of the integrated output shaft and planetary gear A of the present invention. Figure 3 The diagram shown is a schematic diagram of the assembly structure of the integrated sun gear A and planet gear B of the present invention. Figure 4 The diagram shown is a schematic diagram of the output section of this invention; Figure 5 The diagram shown is a schematic of the planetary gear structure of the present invention; Figure 6 The diagram shown is a schematic diagram of the second planetary gear structure of the present invention; Figure 7 The diagram shown is a schematic diagram of the planetary gear structure of the present invention. Figure 8 The diagram shown is a schematic diagram of the planetary gear structure of the present invention.
[0015] In the diagram: 1. Output shaft; 2. Bearing housing; 3. Bearing A; 4. Internal gear ring A; 5. Sun gear A; 6. Bearing B; 7. Internal gear ring B; 8. Planetary gear B; 9. Needle roller bearing; 10. Motor gear; 11. Motor pin; 12. Gear connecting sleeve; 13. Motor; 14. Planetary gear pin A; 15. Washer A; 16. Planetary gear A; 17. Needle roller; 18. Planetary gear pin B; 19. Washer B; 20. Planetary carrier cover plate; 21. Planetary carrier; 22. Sun gear B; 23. Planetary gear C; 24. Planetary gear pin C; 25. Connecting flange; 26. Transmission pin; 27. Locking pin; 28. Cover plate. Detailed Implementation
[0016] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.
[0017] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0019] Example 1, as Figures 1-5As shown, a planetary gearbox is disclosed, comprising a first-stage transmission, a second-stage transmission, and a third-stage transmission; The primary transmission includes a planetary gear C23 located on one side of the planetary carrier 21 and meshing with an external transmission mechanism; the planetary gear C23 is sleeved on a needle roller bearing, the needle roller bearing is sleeved on a planetary gear pin C24, and the planetary gear pin C24 is fixedly connected to the planetary carrier 21; as Figure 1 As shown, planetary gear C23 is connected to planet carrier 21 through planetary gear pin C24, so that planetary gear C23 can drive planet carrier 21 to rotate when it rotates; The secondary transmission includes a sun gear A5, a sun gear B22 located at the center of the other side of the planet carrier 21, and a planet gear B8 meshing with the sun gear B22. The planet gear B8 is connected to the sun gear A5. Figure 1 As shown, the planetary gear B8 is mounted on the needle roller bearing 9, and the needle roller bearing 9 is mounted on the planetary gear pin B18. The planetary gear pin B18 is fixedly connected to the sun gear A5. The sun gear A5 includes a planet carrier for mounting the planetary gear B8, and the planet carrier and the sun gear A5 are integrally formed. It should be noted that the sun gear A adopts an integral structure, making the sun gear and the planet carrier into one piece. Therefore, the planetary gear B8 is connected to the planet carrier of the sun gear A5 through the planetary gear pin B18. The end face of the planetary gear pin B18 and the needle roller bearing is provided with a washer B19 to prevent direct friction between the bearing end faces. The three-stage transmission includes planetary gears A16, the output end of the sun gear A5 meshes with planetary gears A16, and planetary gears A16 mesh with an output shaft 1. Planetary gears A16 are sleeved on needle rollers 17, and needle rollers 17 are installed in the inner hole of planetary gears A16. The two can rotate relative to each other. The output shaft 1 of the gearbox is an integrated planetary carrier, which simultaneously provides output torque, planetary carrier mounting, and support for planetary gears. Planetary gears A16 are mounted on the integrated planetary carrier of the output shaft 1 via planetary pins A14 and needle rollers 17. The end faces of planetary pins A14 and needle rollers 17 are also provided with washers 15A to prevent direct friction between bearing end faces. Planetary gears C23 and B8 are externally meshed with internal gear ring B7, and planetary gear A16 is externally meshed with internal gear ring A4, as shown below. Figure 2 As shown; The planetary gear A16 has a web structure at at least one end and / or in the middle. The web structure is integral with the planetary gear A16 or is provided at at least one end of the planetary gear A16 via a cover plate 28. Figures 5-8 As shown.
[0020] In this embodiment, a planetary carrier cover plate 20 is provided between the sun gear B22 and the planetary carrier 21 to enhance the rigidity of the planetary carrier.
[0021] like Figure 1As shown in the diagram, during assembly, one end of the output shaft 1 is provided with a bearing A3 via a bearing housing 2, and the other end of the output shaft 1 is provided with a bearing B6, which is installed inside the internal gear ring B7; one end of the internal gear ring B7 is connected to the internal gear ring A4, and the other end is connected to a connecting flange 25, as shown. Figure 2 As shown, the internal gear ring A4 is connected to the bearing housing 2 by a locking pin 27.
[0022] In this embodiment, the transmission mechanism includes a motor 13, the output end of the motor 13 is provided with a gear connecting sleeve 12, the gear connecting sleeve 12 is provided with a motor gear 10, the motor gear 10 meshes with a planetary gear C23, the motor 13 is connected to the end of the internal gear ring B7 through a connecting flange 25, and the gear connecting sleeve 12 is connected to the output end of the motor 13 through a motor pin.
[0023] like Figure 5 As shown, the inner hole of planetary gear A16 has a web structure at only one end, and it is an integral structure. This makes one end of the inner hole small and the other end large, which increases rigidity and facilitates the installation of needle roller bearings.
[0024] Example 2, as Figure 6 As shown, based on Embodiment 1, the inner ends of the planetary gear A16 are fitted with cover plates 28, which increases rigidity and facilitates the installation of needle roller bearings.
[0025] Example 3, as Figure 7 As shown, based on Embodiment 1, the inner hole of planetary gear A16 has an integrally designed web plate at one end and a cover plate 28 structure at the other end, which increases rigidity and facilitates the installation of needle roller bearings.
[0026] Example 4, based on Example 2, adds an integrated web plate mechanism in the middle of the inner hole of planetary gear A16. During assembly, the needle rollers are distributed on both sides to improve rigidity.
[0027] Working principle: The motor drives the motor gear 10 to rotate, and the motor gear 10 meshes with the planet gear C23, driving the planet gear C23 to rotate. The planet gear C23 meshes with the internal gear ring B7 and the motor gear 10 at the same time, thereby driving the planet carrier 21 to rotate. The sun gear B22 is fixed on the planet carrier 21, so it rotates at the same speed as the planet carrier 21. Similarly, when the sun gear B22 rotates, it meshes with the planet gear B8, causing the planet gear B8 to rotate. The planet gear B8 simultaneously meshes with the internal gear ring B7 and the sun gear B22, thereby causing the sun gear A5 (the planet carrier and the sun gear are integrated) to rotate. When the sun gear A5 rotates, it meshes with the planet gear A16, causing the planet gear A16 to rotate. The planet gear A16 simultaneously meshes with the internal gear ring A4 and the sun gear A5, thereby driving the output shaft 1 to rotate (the output shaft and the planet carrier are integrated). Calculation of the reduction ratio of the planetary gearbox: Let the number of teeth of motor gear 10 be Z0, and its speed be N0; the number of teeth of internal gear ring B7 be Z1; the number of teeth of sun gear B22 be Z2, and its speed be N1; the number of teeth of sun gear A5 be Z3, and its speed be N2; the number of teeth of internal gear ring A4 be Z4; and the speed of the output shaft be N3. The transmission relationship is as follows: N1 = (Z1 + Z0) / Z0 * N0; N2 = (Z1 + Z2) / Z2 * N1; N3 = (Z4 + Z3) / Z3 * N2; Therefore, the transmission ratio of the entire planetary gearbox is: N1*N2*N3=(Z1+Z0)* (Z1+Z2) *(Z4+Z3) / (Z0*Z2*Z3).
[0028] 1. This invention uses a three-stage transmission. The number of transmission stages in the reduction gearbox can be increased (4 stages, 5 stages, 6 stages, etc.) or decreased (one stage and two stages). 2. In this invention, only the second-stage sun gear is made into an integrated sun gear. If the load to be transmitted is larger, each stage of transmission sun gear can be made into an integrated sun gear like sun gear A5.
[0029] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A planetary gearbox, characterized in that, Including primary transmission, secondary transmission and tertiary transmission; The primary transmission includes a planetary gear C (23) located on one side of the planet carrier (21) and meshing with an external transmission mechanism. The secondary transmission includes a sun gear A (5), a sun gear B (22) located at the center of the other side of the planet carrier (21), and a planet gear B (8) meshing with the sun gear B (22). The planet gear B (8) is connected to the sun gear A (5). The three-stage transmission includes a planetary gear A (16), the output end of the sun gear A (5) meshes with the planetary gear A (16), and the planetary gear A (16) meshes with an output shaft (1). Among them, the planetary gear C (23) and planetary gear B (8) are externally meshed with an internal gear ring B (7), the planetary gear A (16) is externally meshed with an internal gear ring A (4), and the inner hole of the planetary gear A (16) is provided with a web structure at at least one end and / or in the middle.
2. The planetary gearbox according to claim 1, characterized in that, A planetary carrier cover plate (20) is provided between the sun gear B (22) and the planet carrier (21).
3. The planetary gearbox according to claim 1, characterized in that, One end of the output shaft (1) is provided with a bearing A (3) through a bearing seat (2), and the other end of the output shaft (1) is provided with a bearing B (6). The bearing B (6) is installed inside the internal gear ring B (7). One end of the internal gear ring B (7) is connected to the internal gear ring A (4), and the other end is connected to a connecting flange (25).
4. The planetary gearbox according to claim 1, characterized in that, The planetary gear B (8) is mounted on the needle roller bearing (9), the needle roller bearing (9) is mounted on the planetary gear pin B (18), and the planetary gear pin B (18) is fixedly connected to the sun gear A (5).
5. The planetary gearbox according to claim 1, characterized in that, The planetary gear C (23) is mounted on the needle roller bearing, the needle roller bearing is mounted on the planetary pin C (24), and the planetary pin C (24) is fixedly connected to the planet carrier (21).
6. The planetary gearbox according to claim 1, characterized in that, The planetary gear A (16) is sleeved on the needle roller (17), and the needle roller (17) is installed in the inner hole of the planetary gear A (16), and the two can rotate relative to each other.
7. The planetary gearbox according to claim 1, characterized in that, The web structure is integral with the planetary gear A (16) or disposed at at least one end of the planetary gear A (16) via a cover plate (28).
8. The planetary gearbox according to claim 1, characterized in that, The transmission mechanism includes a motor (13), the output end of which is provided with a gear connecting sleeve (12), the gear connecting sleeve (12) is provided with a motor gear (10), and the motor gear (10) meshes with a planetary gear C (23).
9. The planetary gearbox according to claim 1, characterized in that, The output shaft (1) includes a planetary carrier, which are integrated into one unit.
10. The planetary gearbox according to claim 1, characterized in that, The sun gear A (5) includes a planet carrier for mounting the planet gear B (8), and the planet carrier and the sun gear A (5) are integral.