Rear-row planet carrier assembly and dynamic balance control method thereof

Abstract

The rear-row planet carrier assembly comprises a rear-row planet carrier body, a long planet gear assembly and a short planet gear assembly, the long planet gear assembly is arranged on the rear-row planet carrier body, the short planet gear assembly is arranged on the rear-row planet carrier body, and the invention further provides a dynamic balance management and control method of the rear-row planet carrier assembly. The unbalance amount of the rear-row planet carrier assembly can be effectively reduced, the problem that the dynamic balance of the rear-row planet carrier assembly does not reach the standard can be avoided, the problem that the rear-row planet carrier assembly and a transmission generate obvious howling or abnormal sound is avoided, the loss of the rear-row planet carrier assembly and the transmission is reduced, and the service life of the rear-row planet carrier assembly is prolonged. The service life of the rear-row planet carrier assembly and the transmission is prolonged, and the driving experience and the vehicle stability are improved.

Description

Technical Field

[0001] This invention belongs to the field of dynamic balancing of rear planetary carrier assemblies. Specifically, this invention relates to a rear planetary carrier assembly and its dynamic balancing control method. Background Technology

[0002] The rear planetary carrier assembly is one of the core components of an automatic transmission. It participates in the power transmission of each gear, enabling the car to move forward, backward, and at different speeds. The rear planetary carrier assembly transmits power and changes the gear ratio through the meshing relationship between planetary gears, the sun gear, and the ring gear. When the rear planetary carrier is fixed, the power of the sun gear is transmitted to the rear ring gear through the planetary gears, achieving speed reduction. When the rear planetary carrier is used as an output component, the rotation of the planetary gears will drive the rear planetary carrier to rotate, outputting power.

[0003] Dynamic balancing of the rear planetary carrier assembly is a core technological requirement for ensuring stable operation under high-speed rotation, reducing vibration and noise, and extending service life. It is particularly crucial in high-speed transmission scenarios such as automotive automatic transmissions. The essence of dynamic balancing is to eliminate the imbalance of centrifugal force in rotating components at high speeds. Dynamic balancing must meet two requirements: ensuring that the assembly's center of gravity coincides with the axis of rotation, with no spontaneous deflection tendency when stationary; and ensuring that the resultant centrifugal force in all directions is zero when the assembly rotates at high speeds, avoiding dynamic loads caused by mass eccentricity. As a rotating component, if the mass distribution of the rear planetary carrier assembly, its planetary gear shafts, and planetary gears is misaligned, periodic centrifugal forces will be generated during rotation, causing vibration, noise, and even bearing wear and gear meshing failure.

[0004] Therefore, in order to improve or solve at least one of the above problems, a method for controlling the dynamic balance of the rear planetary carrier assembly is provided that can effectively reduce the imbalance of the rear planetary carrier assembly, avoid the problem of substandard dynamic balance of the rear planetary carrier assembly, avoid the problem of obvious whistling or abnormal noise of the rear planetary carrier assembly and transmission, reduce the wear of the rear planetary carrier assembly and transmission, improve the service life of the rear planetary carrier assembly and transmission, and improve the driving experience and vehicle stability. Summary of the Invention

[0005] This invention addresses the aforementioned problems and aims to provide a rear planetary carrier assembly and its dynamic balance control method that effectively reduces the imbalance of the rear planetary carrier assembly, avoids substandard dynamic balance in the rear planetary carrier assembly, prevents significant whistling or abnormal noise from the rear planetary carrier assembly and transmission, reduces wear and tear on the rear planetary carrier assembly and transmission, extends the service life of the rear planetary carrier assembly and transmission, and improves driving experience and vehicle stability. To achieve the above objectives, the technical solution adopted by this invention is as follows: The present invention provides a rear planetary carrier assembly, characterized by including a rear planetary carrier body, a long planetary gear assembly, and a short planetary gear assembly, wherein the long planetary gear assembly is disposed on the rear planetary carrier body, and the short planetary gear assembly is disposed on the rear planetary carrier body.

[0006] The rear planetary carrier assembly provided by this invention may also have the following features: the long planetary gear assembly includes a long planetary gear, a long planetary gear needle roller bearing, a long planetary gear shaft, a long planetary gear copper washer, and a long planetary gear steel washer. The long planetary gear shaft is connected to the rear planetary carrier body. The long planetary gear needle roller bearing is sleeved on the long planetary gear shaft. The long planetary gear is sleeved on the outer ring of the long planetary gear needle roller bearing. The long planetary gear copper washer is sleeved on the long planetary gear shaft and located on both sides of the long planetary gear. The long planetary gear steel washer is sleeved on the long planetary gear shaft and located between the long planetary gear and the long planetary gear copper washer.

[0007] The rear planetary carrier assembly provided by this invention may also have the following features: the short planetary gear assembly includes a short planetary gear, a short planetary gear needle roller bearing, a short planetary gear shaft, a short planetary gear copper washer, and a short planetary gear steel washer. The short planetary gear shaft is connected to the rear planetary carrier body. The short planetary gear needle roller bearing is sleeved on the short planetary gear shaft. The short planetary gear is sleeved on the outer ring of the short planetary gear needle roller bearing. The short planetary gear copper washer is sleeved on the short planetary gear shaft and located on both sides of the short planetary gear. The short planetary gear steel washer is sleeved on the short planetary gear shaft and located between the short planetary gear and the short planetary gear copper washer.

[0008] The rear planetary carrier assembly provided by the present invention may also have the following features: it further includes a S2 sun gear and an S3 sun gear, with the long planetary gear meshing with the S2 sun gear and the short planetary gear meshing with the S3 sun gear.

[0009] The rear planetary carrier assembly provided by the present invention may also have the following features: the S2 sun gear is connected to the S2 bushing, the S2 bushing is engaged with the S3 sun gear shaft; the S3 sun gear is connected to the S3 bushing, the S3 bushing is engaged with the intermediate shaft.

[0010] The rear planetary carrier assembly provided by the present invention may also include a one-way clutch, which is disposed on the rear planetary carrier body.

[0011] The present invention also provides a dynamic balance control method for the rear planetary carrier assembly described above, characterized by the following steps: Step P1, dynamic balance pre-test of the rear planetary carrier body; Step P2, grouping of long planetary gear assemblies; Step P3, grouping of short planetary gear assemblies; Step P4, assembly and riveting of assemblies in the same group; Step P5, dynamic balance test and closed-loop verification of the rear planetary carrier assembly.

[0012] The dynamic balance control method provided by this invention may also have the following feature: in step P2, the long planetary gear, the long planetary gear needle roller bearing, the long planetary gear shaft, the long planetary gear copper washer, and the long planetary gear steel washer are assembled, and the long planetary gear assembly is weighed and grouped according to m1 + n1 * 0.2g, where m1 is the minimum value of the weighing result, n1 = 1, 2, 3, 4, 5..., and the groups are recorded as A1, B1, C1, D1, E1, F1, G1, H1, I1, J1, K1, L1, M1, N1 in sequence.

[0013] The dynamic balance control method provided by this invention may also have the following feature: in step P3, the short planetary gear, the short planetary gear needle roller bearing, the short planetary gear shaft, the short planetary gear copper washer, and the short planetary gear steel washer are assembled, and the short planetary gear assembly is weighed and grouped according to m2 + n2 * 0.2g, where m2 is the minimum value of the weighing result, n2 = 1, 2, 3, 4, 5..., and the groups are recorded as A2, B2, C2, D2, E2, F2, G2, H2, I2, J2, K2, L2, M2, N2 in sequence.

[0014] The dynamic balance control method provided by the present invention may also have the following feature: in step P4, four sets of long planetary gear assemblies and short planetary gear assemblies of the same group are selected and installed into the rear planetary carrier body, and the four long planetary gear shafts and short planetary gear shafts are riveted to the rear planetary carrier body to form the rear planetary carrier assembly. The technical effects of this invention are as follows: The rear planetary carrier assembly provided by this invention includes a rear planetary carrier body, a long planetary gear assembly, and a short planetary gear assembly. The long planetary gear assembly is disposed on the rear planetary carrier body, and the short planetary gear assembly is disposed on the rear planetary carrier body. This invention also provides a dynamic balance control method for the rear planetary carrier assembly, which can effectively reduce the imbalance of the rear planetary carrier assembly, avoid the problem of substandard dynamic balance of the rear planetary carrier assembly, avoid obvious whistling or abnormal noise from the rear planetary carrier assembly and transmission, reduce wear and tear on the rear planetary carrier assembly and transmission, improve the service life of the rear planetary carrier assembly and transmission, and improve the driving experience and vehicle stability. Attached Figure Description

[0015] This manual includes the following figures, which illustrate the following: Figure 1 This is a schematic diagram of the rear planetary carrier assembly in an embodiment of the present invention; The components marked in the diagram are: rear planetary carrier body - 10, long planetary gear assembly - 20, long planetary gear - 21, long planetary gear needle roller bearing - 22, long planetary gear shaft - 23, long planetary gear copper washer - 24, long planetary gear steel washer - 25, short planetary gear assembly - 30, short planetary gear - 31, short planetary gear needle roller bearing - 32, short planetary gear shaft - 33, short planetary gear copper washer - 34, short planetary gear steel washer - 35, S2 sun gear - 40, S3 sun gear - 50, S2 bushing - 60, S3 bushing - 70, intermediate shaft - 80, one-way clutch - 90. Detailed Implementation

[0016] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0017] Figure 1 This is a schematic diagram of the rear planetary carrier assembly in an embodiment of the present invention.

[0018] like Figure 1 As shown, the rear planetary carrier assembly provided by the present invention includes a rear planetary carrier body 10, a long planetary gear assembly 20, and a short planetary gear assembly 30. The long planetary gear assembly 20 is disposed on the rear planetary carrier body 10, and the short planetary gear assembly 30 is disposed on the rear planetary carrier body 10. The present invention also provides a dynamic balance control method for the rear planetary carrier assembly, which can effectively reduce the imbalance of the rear planetary carrier assembly, avoid the problem of substandard dynamic balance of the rear planetary carrier assembly, avoid obvious whistling or abnormal noise problems of the rear planetary carrier assembly and transmission, help reduce the wear of the rear planetary carrier assembly and transmission, help improve the service life of the rear planetary carrier assembly and transmission, and help improve the driving experience and vehicle stability.

[0019] The long planetary gear assembly 20 includes a long planetary gear 21, a long planetary gear needle roller bearing 22, a long planetary gear shaft 23, a long planetary gear copper washer 24, and a long planetary gear steel washer 25. The long planetary gear shaft 23 is connected to the rear planetary carrier body 10. The end of the long planetary gear shaft 23 is fixed to the rear planetary carrier body 10 by riveting. The long planetary gear needle roller bearing 22 is sleeved on the long planetary gear shaft 23. The long planetary gear 21 is sleeved on the outer ring of the long planetary gear needle roller bearing 22. The inner ring of the long planetary gear needle roller bearing 22 is tightly fitted to the outer surface of the long planetary gear shaft 23. The long planetary gear needle roller bearing 22 and the long planetary gear shaft 23 are connected by an transition fit. The inner bore of the long planetary gear needle roller bearing 22 is interference-fitted with the outer ring of the long planetary gear needle roller bearing 22. This ensures that the long planetary gear needle roller bearing 22 will not move relative to the long planetary gear shaft 23, and also allows the inner ring of the long planetary gear needle roller bearing 22 to remain stable synchronously with the long planetary gear shaft 23. The long planetary gear shaft 23 revolves with the planet carrier, while the needle rollers inside the long planetary gear needle roller bearing 22 can roll flexibly, providing low-friction rotational support for the rotation of the long planetary gear 21. The long planetary gear copper washer 24 is sleeved on the long planetary gear shaft 23, and the two long planetary gear copper washers 24 are located on both sides of the long planetary gear 21. The long planetary gear steel washer 25 is sleeved on the long planetary gear shaft 23, located between the long planetary gear 21 and the long planetary gear copper washer 24. Among them, the long planetary gear copper shim 24 has good toughness and self-lubrication. Its toughness buffers the impact load when the planetary gear is running. At the same time, the softness of copper can avoid end face scratches caused by hard metal contact. The long planetary gear steel shim 25 has strong wear resistance and low friction coefficient, which can reduce the friction loss between the end face of the long planetary gear 21 and the planet carrier. It can also reduce the heat generation during the transmission process, further improving the service life and transmission efficiency of the components.

[0020] The short planetary gear assembly 30 includes a short planetary gear 31, a short planetary gear needle roller bearing 32, a short planetary gear shaft 33, a short planetary gear copper washer 34, and a short planetary gear steel washer 35. The short planetary gear shaft 33 is connected to the rear planetary carrier body 10. The end of the short planetary gear shaft 33 is fixed to the rear planetary carrier body 10 by riveting. The short planetary gear needle roller bearing 32 is sleeved on the short planetary gear shaft 33. The short planetary gear 31 is sleeved on the outer ring of the short planetary gear needle roller bearing 32. The inner ring of the short planetary gear needle roller bearing 32 is in close contact with the outer surface of the short planetary gear shaft 33. The short planetary gear needle roller bearing 32 and the short planetary gear shaft 33 are connected by an transition fit. The inner bore of the short planetary gear needle roller bearing 32 is interference-fitted with the outer ring of the short planetary gear needle roller bearing 32. This ensures that the short planetary gear needle roller bearing 32 will not move relative to the short planetary gear shaft 33, and also allows the inner ring of the short planetary gear needle roller bearing 32 to remain stable synchronously with the short planetary gear shaft 33. The short planetary gear shaft 33 revolves with the planet carrier, while the needle rollers inside the short planetary gear needle roller bearing 32 can roll flexibly, providing low-friction rotational support for the rotation of the short planetary gear 31. The short planetary gear copper washer 34 is sleeved on the short planetary gear shaft 33, and the two short planetary gear copper washers 34 are located on one side of the short planetary gear 31 respectively. The short planetary gear steel washer 35 is sleeved on the short planetary gear shaft 33, located between the short planetary gear 31 and the short planetary gear copper washer 34. Among them, the short planetary gear copper shim 34 has good toughness and self-lubrication. Its toughness buffers the impact load during the operation of the planetary gear, while the softness of copper can avoid end face scratches caused by hard metal contact. The short planetary gear steel shim 35 has strong wear resistance and low friction coefficient, which can reduce the friction loss between the end face of the short planetary gear 31 and the planet carrier, and also reduce the heat generation during the transmission process, further improving the service life and transmission efficiency of the components.

[0021] The rear planetary carrier assembly provided by the present invention also includes an S2 sun gear 40 and an S3 sun gear 50. A long planetary gear 21 meshes with the S2 sun gear 40 and simultaneously meshes with both the S2 sun gear 40 and the planetary carrier, thus undertaking the power transmission of the S2 sun gear 40. A short planetary gear 31 meshes with the S3 sun gear 50 and simultaneously meshes with both the S3 sun gear 50 and the planetary carrier, thus undertaking the power transmission of the S3 sun gear 50, thereby accommodating the power coupling of the S2 sun gear 40 and the S3 sun gear 50. The S2 sun gear 40 is connected to the S2 bushing 60, which mates with the S3 sun gear shaft to ensure the coaxial rotational accuracy of the S2 sun gear 40 and the S3 sun gear 50, avoid meshing impact caused by eccentricity, and reduce rotational friction loss between the inner hole of the S2 sun gear 40 and the outer circle of the S3 sun gear shaft. The S3 sun gear 50 is connected to the S3 bushing 70, which mates with the intermediate shaft 80. It serves as a transitional component between the S3 sun gear 50 and the intermediate shaft 80, positioning the axial and radial positions of the S3 sun gear 50, and isolating the intermediate shaft 80 from direct metal-to-metal contact with the S3 sun gear 50 to prevent meshing wear.

[0022] The rear planetary carrier assembly provided by the present invention also includes a one-way clutch 90. The one-way clutch 90 is disposed on the rear planetary carrier body 10. The one-way clutch 90 will brake the rear planetary carrier in one direction to prevent it from rotating in the opposite direction. At this time, the power can be transmitted to the planetary gear through the sun gear, and then drive the ring gear to achieve the same-direction deceleration output, ensuring the stable transmission of forward gear power.

[0023] The present invention also provides a dynamic balance control method for the above-described rear planetary carrier assembly, comprising the following steps: Step P1: Perform dynamic balance pre-test on the rear planetary carrier body 10 and control it within the range of 40 g·mm to screen out unqualified rear planetary carrier bodies 10 in advance and reduce subsequent assembly rework costs.

[0024] Step P2: Grouping of the long planetary gear assembly 20. Assemble the long planetary gear 21, long planetary gear needle roller bearing 22, long planetary gear shaft 23, long planetary gear copper washer 24, and long planetary gear steel washer 25. Weigh the long planetary gear assembly 20 and group it according to m1 + n1 * 0.2g, where m1 is the minimum value of the weighing result, and n1 = 1, 2, 3, 4, 5... The groups are successively labeled A1, B1, C1, D1, E1, F1, G1, H1, I1, J1, K1, L1, M1, N1... For example, the weight of the long planetary gear assembly 20 corresponding to group A1 is between m1 and m1 + 0.2g, i.e., m1 ≤ A1 ≤ m1 +0.2g, the weight of the long planetary gear assembly 20 corresponding to group B1 is between m1+0.2g ​​and m1+0.4g, that is, m1+0.2g<B1≤m1+0.4g, and so on. The 0.2g grouping interval can effectively reduce the influence of the mass deviation of a single group of components on the dynamic balance. The mass deviation of rotating parts is proportional to the amount of imbalance. The smaller the deviation, the better the effect of offsetting the imbalance. At the same time, dynamic balance tests are performed on each group of long planetary gear assemblies 20 and controlled within the range of 5g·mm to avoid the influence of the center of mass eccentricity of the long planetary gear assembly 20 on the dynamic balance of the rear planetary carrier assembly, such as gear ring eccentricity and bearing assembly misalignment.

[0025] Step P3: Grouping of short planetary gear assemblies 30. Assemble the short planetary gears 31, 32, 33, 34, and 35. Weigh the short planetary gear assemblies 30 and group them according to m2 + n2 * 0.2g, where m2 is the minimum weight, and n2 = 1, 2, 3, 4, 5... The groups are sequentially labeled A2, B2, C2, D2, E2, F2, G2, H2, I2, J2, K2, L2, M2, N2... For example, the weight of the short planetary gear assembly 30 corresponding to group A2 is between m2 and m2 + 0.2g, i.e., m2 ≤ A1 ≤ m2 +0.2g, the weight of the short planetary gear assembly 30 corresponding to group B1 is between m2+0.2g ​​and m2+0.4g, that is, m1+0.2g<B1≤m1+0.4g, and so on. The 0.2g grouping interval can effectively reduce the influence of the mass deviation of a single assembly on the dynamic balance. The mass deviation of rotating parts is proportional to the amount of imbalance. The smaller the deviation, the better the effect of offsetting the imbalance. At the same time, dynamic balance tests are performed on each group of short planetary gear assemblies 30 and controlled within the range of 3g·mm to avoid the influence of the center of mass eccentricity of the short planetary gear assembly 30 on the dynamic balance of the rear planetary carrier assembly, such as gear ring eccentricity and bearing assembly misalignment.

[0026] Step P4: Assemble and rivet the same group. Select four sets of long planetary gear assemblies 20 and short planetary gear assemblies 30 of the same group and install them into the rear planetary carrier body 10. Rivet the four long planetary gear shafts 23 and the four short planetary gear shafts 33 to the planetary carrier to form the rear planetary carrier assembly.

[0027] Step P5: Dynamic balance test of the rear planetary carrier assembly, closed-loop verification.

[0028] The dynamic balancing control method provided by this invention achieves precise control of the dynamic balance of the rear planetary carrier assembly. The process is simple and highly repeatable, meeting the needs of industrial mass production. It can effectively reduce the imbalance of the rear planetary carrier assembly, avoid the problem of substandard dynamic balance of the rear planetary carrier assembly, and prevent obvious whistling or abnormal noise from the rear planetary carrier assembly and transmission. It is beneficial to reduce the wear and tear of the rear planetary carrier assembly and transmission, extend the service life of the rear planetary carrier assembly and transmission, and improve the driving experience and vehicle stability.

[0029] The rear planetary carrier assembly provided by this invention includes a rear planetary carrier body 10, a long planetary gear assembly 20, and a short planetary gear assembly 30. The long planetary gear assembly 20 is disposed on the rear planetary carrier body 10, and the short planetary gear assembly 30 is disposed on the rear planetary carrier body 10. This invention also provides a dynamic balance control method for the rear planetary carrier assembly, which can effectively reduce the imbalance of the rear planetary carrier assembly, avoid the problem of substandard dynamic balance of the rear planetary carrier assembly, avoid obvious whistling or abnormal noise problems of the rear planetary carrier assembly and transmission, help reduce the wear of the rear planetary carrier assembly and transmission, help improve the service life of the rear planetary carrier assembly and transmission, and help improve the driving experience and vehicle stability.

[0030] The dynamic balancing control method provided by this invention achieves precise control of the dynamic balance of the rear planetary carrier assembly. The process is simple and highly repeatable, meeting the needs of industrial mass production. It can effectively reduce the imbalance of the rear planetary carrier assembly, avoid the problem of substandard dynamic balance of the rear planetary carrier assembly, and prevent obvious whistling or abnormal noise from the rear planetary carrier assembly and transmission. It is beneficial to reduce the wear and tear of the rear planetary carrier assembly and transmission, extend the service life of the rear planetary carrier assembly and transmission, and improve the driving experience and vehicle stability.

[0031] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A rear planetary carrier assembly, characterized in that, It includes a rear planetary carrier body (10), a long planetary gear assembly (20) and a short planetary gear assembly (30), wherein the long planetary gear assembly (20) is disposed on the rear planetary carrier body (10) and the short planetary gear assembly (30) is disposed on the rear planetary carrier body (10).

2. The rear planetary carrier assembly according to claim 1, characterized in that, The long planetary gear assembly (20) includes a long planetary gear (21), a long planetary gear needle roller bearing (22), a long planetary gear shaft (23), a long planetary gear copper washer (24), and a long planetary gear steel washer (25). The long planetary gear shaft (23) is connected to the rear planetary carrier body (10). The long planetary gear needle roller bearing (22) is sleeved on the long planetary gear shaft (23). The long planetary gear (21) is sleeved on the outer ring of the long planetary gear needle roller bearing (22). The long planetary gear copper washer (24) is sleeved on the long planetary gear shaft (23) and located on both sides of the long planetary gear (21). The long planetary gear steel washer (25) is sleeved on the long planetary gear shaft (23) and located between the long planetary gear (21) and the long planetary gear copper washer (24).

3. The rear planetary carrier assembly according to claim 2, characterized in that, The short planetary gear assembly (30) includes a short planetary gear (31), a short planetary gear needle roller bearing (32), a short planetary gear shaft (33), a short planetary gear copper washer (34), and a short planetary gear steel washer (35). The short planetary gear shaft (33) is connected to the rear planetary carrier body (10). The short planetary gear needle roller bearing (32) is sleeved on the short planetary gear shaft (33). The short planetary gear (31) is sleeved on the outer ring of the short planetary gear needle roller bearing (32). The short planetary gear copper washer (34) is sleeved on the short planetary gear shaft (33) and located on both sides of the short planetary gear (31). The short planetary gear steel washer (35) is sleeved on the short planetary gear shaft (33) and located between the short planetary gear (31) and the short planetary gear copper washer (34).

4. The rear planetary carrier assembly according to claim 1, characterized in that, It also includes an S2 sun gear (40) and an S3 sun gear (50), wherein the long planetary gear (21) meshes with the S2 sun gear (40) and the short planetary gear (31) meshes with the S3 sun gear (50).

5. The rear planetary carrier assembly according to claim 4, characterized in that, The S2 sun gear (40) is connected to the S2 bushing (60), and the S2 bushing (60) is engaged with the S3 sun gear shaft; the S3 sun gear (50) is connected to the S3 bushing (70), and the S3 bushing (70) is engaged with the intermediate shaft (80).

6. The rear planetary carrier assembly according to claim 5, characterized in that, It also includes a one-way clutch (90) disposed on the rear planetary carrier body (10).

7. A method for dynamic balance control of the rear planetary carrier assembly according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step P1, pre-test dynamic balance of the rear planetary carrier body (10); Step P2, group the long planetary gear assembly (20); Step P3, group the short planetary gear assembly (30); Step P4, assemble and rivet the same group; Step P5, test the dynamic balance of the rear planetary carrier assembly and verify the closed loop.

8. The dynamic balancing control method according to claim 7, characterized in that, In step P2, the long planetary gear (21), the long planetary gear needle roller bearing (22), the long planetary gear shaft (23), the long planetary gear copper washer (24), and the long planetary gear steel washer (25) are assembled, and the long planetary gear assembly (20) is weighed and grouped according to m1 + n1 * 0.2g, where m1 is the minimum value of the weighing result, n1 = 1, 2, 3, 4, 5..., and the groups are recorded as A1, B1, C1, D1, E1, F1, G1, H1, I1, J1, K1, L1, M1, N1.

9. The dynamic balancing control method according to claim 8, characterized in that, In step P3, the short planetary gear (31), short planetary gear needle roller bearing (32), short planetary gear shaft (33), short planetary gear copper washer (34) and short planetary gear steel washer (35) are assembled, and the short planetary gear assembly (30) is weighed and grouped according to m2 + n2 * 0.2g, where m2 is the minimum value of the weighing result, n2 = 1, 2, 3, 4, 5..., and the groups are recorded as A2, B2, C2, D2, E2, F2, G2, H2, I2, J2, K2, L2, M2, N2.

10. The dynamic balancing control method according to claim 9, characterized in that, In step P4, four sets of long planetary gear assemblies (20) and short planetary gear assemblies (30) of the same group are selected and installed into the rear planetary carrier body (10). The four long planetary gear shafts (23) and short planetary gear shafts (33) are riveted to the rear planetary carrier body (10) to form the rear planetary carrier assembly.

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