CN220622622U

CN220622622U - Continuously variable planetary gear set transmission mechanism

Info

Publication number: CN220622622U
Application number: CN202322262806.5U
Authority: CN
Inventors: 兰东生; 郑晓娟; 姚兴林; 袁婧; 鲁焱; 刘延民; 王军燕
Original assignee: Cnhtc Jinan Axle Co ltd
Current assignee: Cnhtc Jinan Axle Co ltd
Priority date: 2023-08-22
Filing date: 2023-08-22
Publication date: 2024-03-19
Anticipated expiration: 2033-08-22

Abstract

The utility model provides a continuously variable planetary gear set drive mechanism, belongs to gearbox technical field, includes the planet carrier, and the planet carrier is connected with the planet carrier flange, wears to be equipped with a sun gear axle in planet carrier and the planet carrier flange, and the inside of planet carrier is installed the sun gear through the sun gear axle, and the sun gear is connected with the planetary gear set of No. one; a second sun gear is arranged in the planet carrier flange through a sun gear shaft, and the second sun gear is connected with a second planetary gear set; the first planetary gear set and the second planetary gear set form a double-row planetary gear set structure; the first planetary gear assembly is provided with a first oil duct system for lubrication, and the second planetary gear assembly is provided with a second oil duct system for lubrication. The stepless speed change planetary gear set transmission mechanism has the advantages of reasonable design, ingenious structure, small space occupation, stable and reliable lubrication system, and can prolong the service life of parts to the maximum extent and improve the reliability of the machine.

Description

Continuously variable planetary gear set transmission mechanism

Technical Field

The utility model relates to the technical field of gearboxes, in particular to a continuously variable planetary gear set transmission mechanism.

Background

A transmission, also known as a gearbox, is a mechanism for changing rotational speed and torque from an engine that can fix or shift the ratio of the output shaft to the input shaft. The speed variator consists of speed-changing driving mechanism and operating mechanism, and some automobiles also have power output mechanism. Most of the transmission mechanisms are driven by common gears, and other transmission mechanisms are driven by planetary gears. Common gear transmission speed change mechanisms generally use slipping gears, synchronizers and the like.

The transmission is classified into a stepped transmission, a continuously variable transmission, and a compound transmission, wherein a continuously variable transmission refers to a transmission system that can continuously obtain any gear ratio in a transmission range. The optimal matching of the drive train and the engine working condition can be obtained through stepless speed change. Common continuously variable transmissions are hydromechanical continuously variable transmissions and metal belt type continuously variable transmissions.

At present, the transmission architecture of agricultural machinery is evolving towards mechanical transmission to planetary gear set gearboxes and continuously variable transmission technologies. Although planetary gear sets of existing gearboxes have the advantages of high torque and high efficiency, they generally require more gears to achieve larger gear ratios, the overall structure is not compact enough, which results in larger space occupation, centrifugal force is generated when the planet gears rotate, and because the lubrication effect of the existing gearboxes is general, the abrasion of parts and even faults are easily caused, and the requirements of agricultural machinery on performance and energy efficiency are difficult to meet.

Disclosure of Invention

The utility model aims to overcome the defects of large space occupation and easy abrasion in the prior art, and provides a stepless speed change planetary gear set transmission mechanism which is reasonable in design, ingenious in structure, small in space occupation, stable and reliable in lubrication system, the service life of parts can be prolonged to the greatest extent, and the reliability of a machine can be improved.

The utility model is realized by the following technical scheme: the continuously variable planetary gear set transmission mechanism comprises a planet carrier, wherein the planet carrier is connected with a planet carrier flange, a sun gear shaft penetrates through the planet carrier and the interior of the planet carrier flange, a first sun gear is installed in the planet carrier through the sun gear shaft, and the first sun gear is connected with a first planetary gear set; a second sun gear is arranged in the planet carrier flange through a sun gear shaft, and the second sun gear is connected with a second planetary gear set; the first planetary gear set and the second planetary gear set form a double-row planetary gear set structure; the first planetary gear assembly is provided with a first oil duct system for lubrication, and the second planetary gear assembly is provided with a second oil duct system for lubrication.

When the transmission mechanism operates, the sun wheel shaft is driven by the hydraulic motor to rotate, the sun wheel shaft drives the first sun wheel and the second sun wheel to rotate, the first planetary wheel set rotates around the first sun wheel, and the second planetary wheel set rotates around the second sun wheel, so that continuous adjustment of transmission speed change proportion is realized, stepless speed change is realized, meanwhile, the first oil duct system and the second oil duct system can provide good lubrication, and full lubrication of parts inside the structure is ensured.

The utility model further improves, the first planetary gear set comprises a plurality of first planetary gears, the plurality of first planetary gears are arranged on the periphery of the first sun gear, the first planetary gears are arranged inside the planet carrier through first planetary pin shafts, the first sun gear is meshed with the first planetary gears, an outer gear ring is arranged outside the planet carrier, and the outer gear ring is meshed with the first planetary gears. The first planetary gear set is simple and reasonable in structure and convenient to assemble.

The utility model further improves that the number one planetary gear is three, the number one planetary pin shaft is provided with three, and the three number one planetary gears are uniformly arranged on the periphery of the number one sun gear. The arrangement of the first planetary gear is more reasonable and is convenient to assemble.

According to the utility model, a ring groove is formed in the planet carrier, a first spacer ring is arranged in the ring groove, a first planet pin shaft is fixed on the planet carrier through a groove pin, a cylindrical roller bearing is sleeved on the first planet pin shaft, a first planet wheel is arranged on the first planet pin shaft through the cylindrical roller bearing, and gaskets are arranged on the upper end face and the lower end face of the first planet wheel. The assembly mode is simple, and the assembly cost is low.

The utility model further improves, the first oil duct system comprises a first axial oil duct and a first radial oil duct, the first axial oil duct penetrating through the groove pin is arranged at the axle center of the first planetary pin shaft, a plug is arranged at the position penetrating through the groove pin in the first axial oil duct, a plurality of first radial oil ducts are arranged on the first planetary pin shaft, one end of each first radial oil duct is communicated with the first axial oil duct, and the other end of each first radial oil duct is communicated with the cylindrical roller bearing. The first oil duct system can effectively lubricate the cylindrical roller bearing on the first planetary pin shaft, and the lubricating effect of the first planetary wheel set is greatly improved.

The utility model further improves, the second planetary gear set comprises a plurality of second planetary gears and a plurality of third planetary gears, the plurality of second planetary gears are arranged on the periphery of the second sun gear, the plurality of third planetary gears are arranged on the periphery of the second planetary gears, the second planetary gears and the third planetary gears are respectively arranged in the flange of the planet carrier through second planetary pin shafts, and the second sun gear, the second planetary gears and the third planetary gears are meshed with each other. The second planetary gear set is simple and reasonable in structure and convenient to assemble.

The utility model further improves that the number two planetary gears are three, the number three planetary gears are three, the number two planetary pins are six, the number three planetary gears are uniformly arranged on the periphery of the number two sun gear, one number three planetary gear is arranged between every two adjacent number two planetary gears, and the number three planetary gears are meshed with the number three planetary gears. The arrangement of the second planetary gear and the third planetary gear is more reasonable, and the assembly is convenient.

According to the utility model, a second planetary pin shaft is fixed on a planetary frame flange through a groove pin, two cylindrical roller bearings are sleeved on the second planetary pin shaft, a second spacer ring is arranged between the two cylindrical roller bearings, a second planetary gear and a third planetary gear are arranged on the second planetary pin shaft through the cylindrical roller bearings, and gaskets are arranged on the upper end face and the lower end face of the second planetary gear and the upper end face of the third planetary gear. The assembly mode is simple, and the assembly cost is low.

The utility model further improves, the second oil duct system comprises a second axial oil duct and a second radial oil duct, the second axial oil duct penetrating through the groove pin is arranged at the axle center of the second planetary pin shaft, a plug is arranged at the position of the second axial oil duct penetrating through the groove pin, a plurality of second radial oil ducts are arranged on the second planetary pin shaft, one end of each second radial oil duct is communicated with the second axial oil duct, and the other end of each second radial oil duct is communicated with the cylindrical roller bearing. The second oil duct system can effectively lubricate the cylindrical roller bearing on the second planetary pin shaft, and the lubrication effect of the second planetary wheel set is greatly improved.

The utility model further improves, the axle center of the sun gear shaft is provided with a third axial oil passage, the inside of the third axial oil passage is provided with an orifice at a position close to the planet carrier flange, the sun gear shaft positioned in the planet carrier is provided with a plurality of third radial oil passages a, one end of each third radial oil passage a is communicated with the third axial oil passage, the other end of each third radial oil passage a is communicated with a first sun gear, the sun gear shaft positioned in the planet carrier flange is provided with a plurality of third radial oil passages b, one end of each third radial oil passage b is communicated with the third axial oil passage, and the other end of each third radial oil passage b is communicated with a second sun gear. The structure can effectively lubricate the first sun gear and the second sun gear, and greatly improves the lubrication effect of the sun gears.

From the technical scheme, the beneficial effects of the utility model are as follows: when the transmission mechanism operates, the sun wheel shaft is driven by the hydraulic motor to rotate, and the sun wheel shaft rotates to drive the first planetary gear set and the second planetary gear set to rotate, so that continuous transmission speed ratio adjustment is realized, stepless speed change is further realized, meanwhile, the first oil duct system and the second oil duct system can provide good lubrication, and the full lubrication of parts in the structure is ensured. The transmission mechanism has the advantages of small volume, high efficiency, high bearing torque, stable and reliable lubrication system, full lubrication of parts in the structure, prolonged service life of the parts to the maximum extent and improved reliability of the machine.

Drawings

In order to more clearly illustrate the technical solutions of the present utility model, the drawings that are needed in the description will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of an embodiment of the present utility model.

Fig. 2 is a schematic structural view of a second planetary pin and a cylindrical pin according to an embodiment of the present utility model.

Fig. 3 is a schematic diagram of an embodiment of the present utility model.

1. A planet carrier; 2. a first spacer ring; 3. a sun gear shaft; 4. a rubber seal ring; 5. a first planetary pin shaft; 6. a plug; 7. a grooved pin; 8. a gasket; 9. a first planetary gear set; 10. cylindrical roller bearings; 11. an inner gear ring; 12. a second planetary gear set; 13. a bolt; 14. a planet carrier flange; 15. deep groove ball bearings; 16. an orifice; 17. a circlip; 18. a sun gear; 19. a second spacer ring; 20. a second planetary pin shaft; 21. a cylindrical pin; 22. a clutch; 23. an outer gear ring of the clutch; 24. an outer ring gear; 25. an electronic speed control unit; s1, a first sun gear; s2, a second sun gear; c1, a first planetary gear; c2, a second planet wheel; and c3, a third planetary gear.

Detailed Description

In order to make the objects, features and advantages of the present utility model more obvious and understandable, the technical solutions of the present utility model will be clearly and completely described below with reference to the drawings in this specific embodiment, and it is apparent that the embodiments described below are only some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, based on the embodiments in this patent, which would be within the purview of one of ordinary skill in the art without the particular effort to make the utility model are intended to be within the scope of the patent protection.

Referring now to fig. 1-3, in connection with the specific embodiments, the following is described: the utility model relates to a continuously variable planetary gear set transmission mechanism, which comprises a planet carrier 1, wherein the planet carrier 1 is connected with a planet carrier flange 14 through a cylindrical pin 21 and a bolt 13, a sun gear shaft 3 is arranged in the planet carrier 1 and the planet carrier flange 14 in a penetrating way, and a deep groove ball bearing 15 is sleeved on the shaft of the planet carrier flange 14; a first sun gear s1 is arranged in the planet carrier 1 through a sun gear shaft 3, and the first sun gear s1 is connected with a first planet wheel set 9; a second sun gear s2 is arranged in the planet carrier flange 14 through a sun gear shaft 3, and the second sun gear s2 is connected with a second planetary gear set 12; the first planetary gear set 9 and the second planetary gear set 12 form a double-row planetary gear set structure; the first planetary gear set 9 comprises three first planetary gears c1, wherein the three first planetary gears c1 are uniformly arranged on the periphery of a first sun gear s1, the first planetary gears c1 are arranged inside a planetary carrier 1 through first planetary pin shafts 5, the first sun gear s1 is meshed with the first planetary gears c1, an outer gear ring 24 is arranged outside the planetary carrier 1, and the outer gear ring 24 is meshed with the first planetary gears c 1; the second planetary gear set 12 comprises three second planetary gears c2 and three third planetary gears c3, the three second planetary gears c2 are uniformly arranged on the periphery of the second sun gear s2, one third planetary gear c3 is arranged between every two adjacent second planetary gears c2, the second planetary gears c2 and the third planetary gears c3 are respectively arranged in the planetary carrier flange 14 through second planetary pin shafts 20, and the second sun gear s2, the second planetary gears c2 and the third planetary gears c3 are meshed with each other; the first planetary gear set 9 is provided with a first oil duct system for lubrication, and the second planetary gear set 12 is provided with a second oil duct system for lubrication; the planet carrier 1 is provided with an inner gear ring 11 at the periphery through bolts, the inner gear ring 11 is meshed with an electronic speed control unit 25, and the electronic speed control unit 25 is used for monitoring the rotating speed of the transmission mechanism.

The application principle of the utility model is as follows: the transmission mechanism is arranged inside a gearbox, and lubricating oil inside the gearbox is used for soaking the transmission mechanism. The first sun gear s1 and the second sun gear s2 form a sun gear 18 of the transmission mechanism, and the first sun gear s1 and the second sun gear s2 are in interference fit with the sun gear shaft 3 and are abutted against the planet carrier flange 14. The sun gear shaft 3 is provided with a sealing groove and a check ring groove, the rubber sealing ring 4 is arranged in the sealing groove, and the elastic check ring 17 is arranged in the check ring groove. The transmission mechanism is connected with a clutch 22 through the shaft of the planet carrier flange 14, an outer gear ring 23 of the clutch is meshed with a third planetary gear of the second planetary gear set 12, and the clutch 22 is connected with a hydraulic motor.

When the transmission mechanism operates, the hydraulic motor drives the sun gear shaft to rotate, so that the sun gear 18 is controlled to rotate, and the sun gear 18 rotates to enable the first planetary gear set to rotate around the first sun gear and the second planetary gear set to rotate around the second sun gear. Specifically, a first sun gear s1 is positioned at the center, and a first planet wheel c1 is meshed with the first sun gear s1 through a planet carrier 1 and rotates around the first sun gear s 1; the second sun gear s2 is positioned at the center, and the second planet gear c2 is meshed with the third planet gear c3, then meshed with the second sun gear s2 through the planet carrier flange 14 and rotates around the second sun gear s 2; namely, the first planetary gear set 9 and the second planetary gear set 12 form a double-row planetary gear set structure. The transmission mechanism realizes the adjustment of transmission proportion through the double-row planetary gear set structure, and further realizes the stepless speed change of the inner gear ring 11, the outer gear ring 24 and the clutch outer gear ring 23. The transmission mechanism has the advantages of small volume, space occupation saving, high transmission efficiency and high bearing torque, meanwhile, the first oil duct system and the second oil duct system can provide good lubrication, the full lubrication of parts inside the structure is ensured, the service life of the parts is prolonged, and the reliability of the machine is improved.

In one embodiment, the planet carrier 1 is provided with a ring groove, the first spacer ring 2 is installed inside the ring groove, the first planet pin shaft 5 is fixed on the planet carrier 1 through the groove pin 7, the first planet pin shaft 5 is sleeved with a cylindrical roller bearing 10, the first planet wheel c1 is installed on the first planet pin shaft 5 through the cylindrical roller bearing 10, and gaskets 8 are installed on the upper end face and the lower end face of the first planet wheel c 1. The first oil passage system comprises a first axial oil passage and a first radial oil passage, the first axial oil passage penetrating through the groove pin 7 is formed in the axis of the first planetary pin shaft 5, the plug 6 is arranged at the position penetrating through the groove pin 7 in the first axial oil passage, the first radial oil passage is formed in the first planetary pin shaft 5, one end of the first radial oil passage is communicated with the first axial oil passage, and the other end of the first radial oil passage is communicated with the cylindrical roller bearing 10. When the transmission mechanism operates, the cylindrical roller bearing 10 on the first planetary pin shaft 5 can be effectively lubricated through the first oil duct system, and the lubricating effect of the first planetary wheel set 9 is greatly improved.

In one embodiment, a second planetary pin shaft 20 is fixed on the planet carrier flange 14 through a groove pin 7, two cylindrical roller bearings 10 are sleeved on the second planetary pin shaft 20, a second spacer ring 19 is installed between the two cylindrical roller bearings 10, a second planetary wheel c2 and a third planetary wheel c3 are installed on the second planetary pin shaft 20 through the cylindrical roller bearings 10, and gaskets 8 are installed on the upper end face and the lower end face of the second planetary wheel c2 and the third planetary wheel c 3. The second oil channel system comprises a second axial oil channel and a second radial oil channel, the second axial oil channel which penetrates through the groove pin 7 is formed in the axis of the second planetary pin shaft 20, the plug 6 is arranged at the position which penetrates through the groove pin 7 in the second axial oil channel, a plurality of second radial oil channels are formed in the second planetary pin shaft 20, one end of each second radial oil channel is communicated with each second axial oil channel, and the other end of each second radial oil channel is communicated with the cylindrical roller bearing 10. When the transmission mechanism operates, the cylindrical roller bearing 10 on the second planetary pin shaft 20 can be effectively lubricated through the second oil duct system, and the lubricating effect of the first planetary gear set 12 is greatly improved.

In one embodiment, a third axial oil passage is formed at the axle center of the sun gear shaft 3, an orifice 16 is formed in the third axial oil passage at a position close to the planet carrier flange 14, a plurality of third radial oil passages a are formed in the sun gear shaft 3 in the planet carrier 1, one end of each third radial oil passage a is communicated with the third axial oil passage, the other end of each third radial oil passage a is communicated with a first sun gear s1, a plurality of third radial oil passages b are formed in the sun gear shaft 3 in the planet carrier flange 14, one end of each third radial oil passage b is communicated with each third axial oil passage, and the other end of each third radial oil passage b is communicated with a second sun gear s 2. When the transmission mechanism operates, the first sun gear s1 and the second sun gear s2 can be effectively lubricated through the structure, and the lubricating effect of the sun gear 18 is greatly improved.

In the present specification, each embodiment is described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between the embodiments are only required to be referred to each other.

The terms "upper", "lower", "outside", "inside", and the like in the description and in the claims of the present utility model and in the above drawings, if any, are used for distinguishing between relative relationships in position and not necessarily for giving qualitative sense. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the utility model described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. The continuously variable planetary gear set transmission mechanism comprises a planet carrier (1), wherein the planet carrier (1) is connected with a planet carrier flange (14), a sun gear shaft (3) is arranged in the planet carrier (1) and the planet carrier flange (14) in a penetrating manner, and the continuously variable planetary gear set transmission mechanism is characterized in that a first sun gear (s 1) is arranged in the planet carrier (1) through the sun gear shaft (3), and the first sun gear (s 1) is connected with a first planetary gear set (9); a second sun gear (s 2) is arranged in the planet carrier flange (14) through a sun gear shaft (3), and the second sun gear (s 2) is connected with a second planet gear set (12); the first planetary gear set (9) and the second planetary gear set (12) form a double-row planetary gear set structure; the first planetary gear set (9) is provided with a first oil duct system for lubrication, and the second planetary gear set (12) is provided with a second oil duct system for lubrication.

2. A continuously variable planetary gear set transmission according to claim 1, characterized in that the planetary gear set (9) comprises a plurality of planetary gears (c 1), the plurality of planetary gears (c 1) are arranged on the periphery of a sun gear (s 1), the planetary gears (c 1) are mounted inside the planet carrier (1) through planetary pin shafts (5), the sun gear (s 1) is meshed with the planetary gears (c 1), an outer gear ring (24) is mounted outside the planet carrier (1), and the outer gear ring (24) is meshed with the planetary gears (c 1).

3. A continuously variable planetary gearset transmission according to claim 2, characterised in that the first planetary gear (c 1) is provided with three, the first planetary pin (5) is provided with three, and the three first planetary gears (c 1) are evenly arranged on the periphery of the first sun gear (s 1).

4. A continuously variable planetary gear set transmission mechanism according to claim 2 or 3, characterized in that the planet carrier (1) is provided with a ring groove, a first spacer ring (2) is installed in the ring groove, a first planetary pin shaft (5) is fixed on the planet carrier (1) through a groove pin (7), a cylindrical roller bearing (10) is sleeved on the first planetary pin shaft (5), a first planetary wheel (c 1) is installed on the first planetary pin shaft (5) through the cylindrical roller bearing (10), and gaskets (8) are installed on the upper end face and the lower end face of the first planetary wheel (c 1).

5. The continuously variable planetary gear set transmission mechanism according to claim 4, wherein the first oil passage system comprises a first axial oil passage and a first radial oil passage, the first axial oil passage penetrating through the groove pin (7) is formed in the axis of the first planetary pin shaft (5), the plug (6) is arranged at the position penetrating through the groove pin (7) in the first axial oil passage, a plurality of first radial oil passages are formed in the first planetary pin shaft (5), one end of each first radial oil passage is communicated with the first axial oil passage, and the other end of each first radial oil passage is communicated with the cylindrical roller bearing (10).

6. The continuously variable planetary gear set transmission mechanism according to claim 5, wherein the second planetary gear set (12) includes a plurality of second planetary gears (c 2) and a plurality of third planetary gears (c 3), the plurality of second planetary gears (c 2) are arranged on the periphery of the second sun gear (s 2), the plurality of third planetary gears (c 3) are arranged on the periphery of the second planetary gears (c 2), the second planetary gears (c 2) and the third planetary gears (c 3) are respectively installed inside the planet carrier flange (14) through second planetary pin shafts (20), and the second sun gear (s 2), the second planetary gears (c 2) and the third planetary gears (c 3) are meshed with each other.

7. The continuously variable planetary gear set transmission mechanism according to claim 6, wherein the number two planetary gears (c 2) is three, the number three planetary gears (c 3) is three, the number two planetary pins (20) are six, the number three planetary gears (c 2) are uniformly arranged on the periphery of the number two sun gears (s 2), one number three planetary gears (c 3) are arranged between every two adjacent number two planetary gears (c 2), and the number three planetary gears (c 2) are meshed with the number three planetary gears (c 3).

8. The continuously variable planetary gear set transmission mechanism according to claim 7, wherein the second planetary pin shaft (20) is fixed on the planet carrier flange (14) through the groove pin (7), two cylindrical roller bearings (10) are sleeved on the second planetary pin shaft (20), a second spacer ring (19) is installed between the two cylindrical roller bearings (10), the second planetary wheel (c 2) and the third planetary wheel (c 3) are installed on the second planetary pin shaft (20) through the cylindrical roller bearings (10), and gaskets (8) are installed on the upper end face and the lower end face of the second planetary wheel (c 2) and the third planetary wheel (c 3).

9. The continuously variable planetary gear set transmission mechanism according to claim 8, wherein the second oil passage system comprises a second axial oil passage and a second radial oil passage, the second axial oil passage penetrating through the groove pin (7) is formed in the axis of the second planetary pin shaft (20), the plug (6) is arranged at the position penetrating through the groove pin (7) in the second axial oil passage, a plurality of second radial oil passages are formed in the second planetary pin shaft (20), one end of each second radial oil passage is communicated with each second axial oil passage, and the other end of each second radial oil passage is communicated with the cylindrical roller bearing (10).

10. The continuously variable planetary gear set transmission mechanism according to claim 9, wherein a third axial oil passage is formed in the axis of the sun gear shaft (3), an orifice (16) is formed in the third axial oil passage at a position close to the planet carrier flange (14), a plurality of third radial oil passages a are formed in the sun gear shaft (3) located in the planet carrier (1), one end of each third radial oil passage a is communicated with the third axial oil passage, the other end of each third radial oil passage a is communicated with the first sun gear (s 1), a plurality of third radial oil passages b are formed in the sun gear shaft (3) located in the planet carrier flange (14), one end of each third radial oil passage b is communicated with the third axial oil passage, and the other end of each third radial oil passage b is communicated with the second sun gear (s 2).