Double planetary gear reduction drive axle

Abstract

The utility model discloses a double planetary gear reduction drive axle, include: central axle housing, axle housing and wheel edge reduction gear, the wheel edge reduction gear includes first planetary gear reduction mechanism, be provided with second planetary gear reduction mechanism between the central axle housing with axle housing, the power input of second planetary gear reduction mechanism and half axle gear drive connection of differential assembly, the power output of second planetary gear reduction mechanism and first sun gear axle drive connection. The utility model increases the transmission ratio under the premise of not increasing the volume of wheel edge reduction gear, is suitable for and high -speed gearbox matches, and high assembly accuracy, convenient installation, side reduction box does not rotate, and the air is exhausted upwards through the air vent plug, reduces the air pressure, avoids the pollution to the paddy field, makes the conventional planetary reduction dry field bridge upgrade as the water and drought dual -purpose bridge.

Description

Technical Field

[0001] This utility model relates to the field of drive axle technology, and in particular to a drive axle that uses planetary gear reduction transmission. Background Technology

[0002] The drive axle is located at the end of the power transmission system of self-propelled machinery (including tractors, agricultural machinery, etc.) or vehicles (including agricultural vehicles, engineering vehicles, transport vehicles, etc.). Its basic functions are: to transmit the torque output by the engine to the wheel-side reducer through the main reducer, differential, half shaft, etc., thereby driving the wheels and achieving speed reduction and torque increase; to change the direction of torque transmission through the bevel gear pair of the main reducer; to achieve differential speed action of the two wheels through the differential, ensuring that the inner and outer wheels turn at different speeds; and to achieve load bearing and torque transmission through the axle housing and wheels.

[0003] Planetary gear reducers, characterized by their large speed ratio, compact structure, and high transmission torque, are commonly used as wheel-side reducers. A typical planetary gear reducer includes a sun gear shaft, planet carriers, and a ring gear. The planet carrier is fixedly connected to the wheel hub, which is rotatably mounted on the steering knuckle housing via tapered roller bearings. The ring gear is fixed to the steering knuckle housing via threaded connections. However, the aforementioned wheel-side reducers suffer from the following technical drawbacks:

[0004] First, the gear ring needs to be connected to the steering knuckle housing via a threaded connector, making it difficult to guarantee the coaxiality of the sun gear shaft, planetary gear carrier, and gear ring, and the assembly process is cumbersome.

[0005] Secondly, the planetary gear carrier also serves as the end cap of the planetary reduction mechanism, and due to size limitations, it is difficult to adapt to steel rings of different specifications.

[0006] Third, on the one hand, the hub is mounted on the steering knuckle housing, and a dynamic seal needs to be installed between the hub and the steering knuckle housing, which is prone to oil leakage; on the other hand, since the sun gear shaft of the planetary reduction mechanism is not fixed axially, when the steering knuckle housing swings, it will drive the sun gear shaft to be pulled axially, thereby increasing the wear of the oil seal between the sun gear shaft and the steering knuckle housing, which is also prone to oil leakage. When working in paddy fields, oil will pollute the paddy fields.

[0007] Chinese utility model patent CN217944802U discloses a transmission and sealing structure for a steering drive axle. The sun gear shaft and the universal joint short fork are connected by internal and external splines, improving the operating conditions of the oil seal. The sealing motion of the oil seal and sun gear shaft changes from reciprocating pull-rotation to rotation only, improving the durability and service life of the oil seal. However, due to space limitations, the key connection between the sun gear shaft and the universal joint short fork can only be lubricated initially, preventing subsequent maintenance. Furthermore, as the oil temperature and air pressure increase within the planetary reduction mechanism, oil leaks are more likely to occur at the seals of various components.

[0008] In addition, when matched with a high-speed gearbox, the transmission ratio of a single-stage planetary gear reduction mechanism is insufficient. If the wheel-side reducer is set to be connected by a two-stage planetary gear reduction mechanism, the size of the wheel-side reducer will inevitably increase, making it unsuitable for matching with the tractor. Utility Model Content

[0009] In view of this, the technical problem to be solved by this utility model is to provide a double planetary gear reduction drive axle that improves the transmission ratio without increasing the volume of the wheel-side reducer, and better matches the high-speed gearbox.

[0010] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0011] A dual planetary gear reducer drive axle includes: a central axle housing and a half-shaft housing; a differential assembly, which is driven and connected to an input bevel gear shaft, is disposed within the central axle housing; a wheel-side reducer includes a first planetary gear reduction mechanism, which includes a first sun gear shaft, first planetary gears, a first planetary gear carrier, and a first ring gear; the first planetary gear carrier includes an outer planetary gear carrier and an inner planetary gear carrier connected together, and the first planetary gears are rotatably mounted between the outer planetary gear carrier and the inner planetary gear carrier; a second planetary gear reduction mechanism is disposed between the central axle housing and the half-shaft housing, the power input end of the second planetary gear reduction mechanism is driven and connected to the half-shaft gear of the differential assembly, and the power output end of the second planetary gear reduction mechanism is driven and connected to the first sun gear shaft.

[0012] The second planetary gear reduction mechanism includes a second sun gear shaft, a second planetary gear, a second planetary gear carrier, a second ring gear, and a second planetary reduction housing. The second planetary reduction housing is fixed between the central axle housing and the half-shaft housing. The second ring gear is fixed inside the second planetary reduction housing. The second sun gear shaft is connected to the half-shaft gear of the differential assembly. The second planetary gear carrier is connected to the first sun gear shaft.

[0013] The wheel-side reducer includes a wheel-side reducer housing. The first planetary gear reducer mechanism is installed inside the wheel-side reducer housing. The wheel-side reducer housing includes a wheel-side reducer housing body, a first wheel-side reducer housing cover, and a second wheel-side reducer housing cover. The wheel-side reducer housing body is fixedly connected to the half-shaft housing. The first wheel-side reducer housing cover is fixedly connected to the wheel-side reducer housing body. The second wheel-side reducer housing cover, the gear ring, and the wheel-side reducer housing body are fixedly connected together. The outer planetary gear carrier is provided with a shaft head. The shaft head is rotatably mounted on the first wheel-side reducer housing cover and extends out of the first wheel-side reducer housing cover via a first bearing. The inner planetary gear carrier is rotatably mounted on the second wheel-side reducer housing cover via a second bearing. The first sun gear shaft is rotatably mounted on the outer planetary gear carrier via a third bearing and rotatably mounted on the inner planetary gear carrier via a fourth bearing. One end of the first sun gear shaft passes through the mounting hole of the second wheel-side reducer housing cover and is connected to the second planetary gear carrier in a transmission connection.

[0014] A first oil seal is provided between the shaft head and the first side reduction box cover.

[0015] The top of the side reduction box is equipped with a vent plug.

[0016] The axle head is fixedly connected to a hub connecting disc.

[0017] After adopting the above technical solution, the beneficial effects of this utility model are:

[0018] The dual planetary gear reduction drive axle disclosed in this utility model has a first planetary gear reduction mechanism in the wheel-side reducer and a second planetary gear reduction mechanism between the central axle housing and the half-shaft housing, thus forming a dual planetary gear reduction mechanism. This increases the transmission ratio without increasing the volume of the wheel-side reducer, making it suitable for matching with high-speed gearboxes.

[0019] In this utility model, the first planetary gear reduction mechanism is installed inside the side reduction gearbox. The side reduction gearbox includes a side reduction gearbox body, a first side reduction gearbox cover, and a second side reduction gearbox cover. The side reduction gearbox body is fixedly connected to the half-shaft housing, and the first side reduction gearbox cover is fixedly connected to the side reduction gearbox body. The second side reduction gearbox cover, the gear ring, and the side reduction gearbox body are fixedly connected together. The side reduction gearbox does not rotate relative to the half-shaft housing. The first gear ring is directly fixed inside the side reduction gearbox body and does not need to be connected to the steering knuckle housing through a threaded connector, making installation convenient. The inner hole and outer... The circle can be machined in one clamping and the fourth and second bearings can be installed separately. The inner hole and outer circle of the outer planetary gear carrier can be machined in one clamping and the third and first bearings can be installed separately. The third and fourth bearings are used to support the first sun gear shaft between the outer planetary gear carrier and the inner planetary gear carrier. The first bearing is used to support the outer planetary gear carrier on the first side reduction gear cover. The second bearing is used to support the inner planetary gear carrier on the second side reduction gear cover. Therefore, the coaxiality of the first sun gear shaft, the first planetary gear carrier and the first gear ring is easy to ensure, which improves the assembly accuracy.

[0020] In this invention, the outer planetary gear carrier is provided with a shaft head, which is rotatably mounted on the first side reduction gear cover and extends out of the first side reduction gear cover via a first bearing. The shaft head is fixedly connected to a hub connecting plate. By replacing the hub connecting plate, it can be adapted to steel rings of different specifications, thereby improving the adaptability of the drive axle.

[0021] In this invention, the side reduction gearbox does not rotate, so a vent plug can be installed on the top of the side reduction gearbox. When the oil temperature and air pressure in the planetary reduction mechanism rise, the air can be vented upward through the vent plug, reducing the air pressure and solving the problem of oil leakage from the side reduction gearbox. This avoids pollution to paddy fields and upgrades the conventional planetary reduction dryland bridge into a bridge suitable for both dry and paddy fields. Attached Figure Description

[0022] Figure 1 This is a longitudinal sectional view of an embodiment of the dual planetary gear reduction drive axle of this utility model;

[0023] In the picture:

[0024] 10. Hub connecting plate; 11. First sun gear shaft; 12A. Outer planetary gear carrier; 12B. Inner planetary gear carrier; 13. First gear ring; 14. First bearing; 15. Second bearing; 16. Third bearing; 17. Fourth bearing; 18. First planetary gear; 19. First oil seal; 21. Side reduction gearbox; 22. First side reduction gearbox cover; 23. Second side reduction gearbox cover; 25. Breather plug; 26. Oil drain plug; 5. Half-shaft housing; 6. Second planetary gear reduction mechanism; 61. Second planetary reduction housing; 62. Second gear ring; 63. Second planetary gear; 64. Second planetary gear carrier; 65. Second sun gear shaft; 7. Central axle housing; 8. Differential assembly; 81. Differential housing; 82. Half-shaft gear; 91. Input bevel gear shaft; 92. Central drive bevel gear. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] Example

[0027] like Figure 1 As shown, a dual planetary gear reduction drive axle has a differential assembly 8 housed in the central axle housing 7, which is connected to the input bevel gear shaft 91 for transmission. The differential assembly 8 includes a differential housing 81 and a half-shaft gear 82.

[0028] A second planetary gear reduction mechanism 6 is disposed between the central axle housing 7 and the half-shaft housing 5. The power input end of the second planetary gear reduction mechanism 6 is connected to the half-shaft gear 82 of the differential assembly 8, and the power output end of the second planetary gear reduction mechanism 6 is connected to the first sun gear shaft 11. The second planetary gear reduction mechanism 6 includes a second sun gear shaft 65, a second planetary gear 63, a second planetary gear carrier 64, a second ring gear 62, and a second planetary reduction housing 61. The second planetary reduction housing 61 is fixed between the central axle housing 7 and the half-shaft housing 5, the second ring gear 62 is fixed inside the second planetary reduction housing 61, the second sun gear shaft 65 is connected to the half-shaft gear 82 of the differential assembly 8, and the second planetary gear carrier 64 is connected to the first sun gear shaft 11.

[0029] The wheel-side reducer includes a first planetary gear reduction mechanism, which comprises a first sun gear shaft 11, first planetary gears 18, a first planetary gear carrier, and a first ring gear 13. The first planetary gear carrier includes an outer planetary gear carrier 12A and an inner planetary gear carrier 12B connected together. The first planetary gears 18 are rotatably mounted between the outer planetary gear carrier 12A and the inner planetary gear carrier 12B. The first planetary gear reduction mechanism has a large speed ratio, a compact structure, and a large transmission torque.

[0030] The dual planetary gear reduction drive axle disclosed in this utility model has a first planetary gear reduction mechanism in the wheel-side reducer and a second planetary gear reduction mechanism between the central axle housing and the half-shaft housing, thus forming a dual planetary gear reduction mechanism. This increases the transmission ratio without increasing the volume of the wheel-side reducer, making it suitable for matching with high-speed gearboxes.

[0031] In this embodiment, the wheel-side reducer further includes a side reduction gearbox. The first planetary gear reduction mechanism is installed inside the side reduction gearbox. The side reduction gearbox includes a side reduction gearbox body 21, a first side reduction gearbox cover 22, and a second side reduction gearbox cover 23. The side reduction gearbox body 21 is fixedly connected to the half-shaft housing 5. The first side reduction gearbox cover 22 is fixedly connected to the side reduction gearbox body 21. The second side reduction gearbox cover 23A, the gear ring 13, and the side reduction gearbox body 21 are fixedly connected together. The outer planetary gear carrier 12A is provided with a shaft head. The shaft head is rotatably mounted on the first side reduction gearbox cover 22 and extends out of the first side reduction gearbox cover 22 via a first bearing 14. A first oil seal 19 is provided between the shaft head and the first side reduction gearbox cover 22. The inner planetary gear carrier 12B is rotatably mounted to the second side reduction gearbox cover 23 via the second bearing 15. The first sun gear shaft 11 is rotatably mounted to the outer planetary gear carrier 12A via the third bearing 16, and rotatably mounted to the inner planetary gear carrier 12B via the fourth bearing 17. One end of the first sun gear shaft 11 passes through the mounting hole of the second side reduction gearbox cover 23 and is connected to the second planetary gear carrier 64 for transmission. An oil drain plug 26 is provided at the bottom of the side reduction gearbox 21. The first bearing 14 is preferably a cylindrical roller bearing, while the second bearing 15, third bearing 16, and fourth bearing 17 are preferably ball bearings.

[0032] The above structure ensures that the reducer box does not rotate relative to the half-shaft housing during operation. The first gear ring 13 is directly fixed inside the reducer box body 21, without needing to be connected to the steering knuckle housing 31 via threaded connectors, making installation convenient. The inner hole and outer circle of the inner planetary gear carrier 12B can be machined in one clamping and respectively installed with the fourth bearing 17 and the second bearing 15. The inner hole and outer circle of the outer planetary gear carrier 12A can be machined in one clamping and respectively installed with the third bearing 16 and the first bearing 14. The third bearing 16 and the fourth bearing 17 are used to support the first sun gear shaft 11 between the outer planetary gear carrier 12A and the inner planetary gear carrier 12B. The first bearing 14 is used to support the outer planetary gear carrier 12A on the first reducer box cover 22. The second bearing 15 is used to support the inner planetary gear carrier 12B on the second reducer box cover 23. Therefore, the coaxiality of the first sun gear shaft 11, the first planetary gear carrier, and the first gear ring 13 is easily guaranteed, improving assembly accuracy.

[0033] In this embodiment, the axle head is fixedly connected to a hub connecting plate 10. By replacing the hub connecting plate 10, it can be adapted to steel rings of different specifications, thereby improving the adaptability of the drive axle.

[0034] In this embodiment, a vent plug 25 is provided on the top of the side reduction gearbox 21. When the oil temperature and air pressure rise in the planetary reduction mechanism, the air can be vented upward through the vent plug 25, which reduces the air pressure, solves the problem of oil leakage in the side reduction gearbox, avoids pollution to the paddy field, and upgrades the conventional planetary reduction dryland bridge into a bridge suitable for both dryland and paddy fields.

[0035] This utility model is not limited to the above embodiments. All improvements made based on the concept, principle, structure and method of this utility model shall fall within the protection scope of this utility model.

Claims

1. A dual planetary gear reduction drive axle, comprising: A central axle housing and a half-shaft housing, wherein a differential assembly that is connected to the input bevel gear shaft drive is provided inside the central axle housing; A wheel-side reducer, comprising a first planetary gear reduction mechanism, the first planetary gear reduction mechanism comprising a first sun gear shaft, a first planetary gear, a first planetary gear carrier, and a first ring gear, the first planetary gear carrier comprising an outer planetary gear carrier and an inner planetary gear carrier connected together, the first planetary gear being rotatably mounted between the outer planetary gear carrier and the inner planetary gear carrier; characterized in that... A second planetary gear reduction mechanism is provided between the central axle housing and the half-shaft housing. The power input end of the second planetary gear reduction mechanism is connected to the half-shaft gear of the differential assembly, and the power output end of the second planetary gear reduction mechanism is connected to the first sun gear shaft.

2. The dual planetary gear reduction drive axle as described in claim 1, characterized in that, The second planetary gear reduction mechanism includes a second sun gear shaft, a second planetary gear, a second planetary gear carrier, a second ring gear, and a second planetary reduction housing. The second planetary reduction housing is fixed between the central axle housing and the half-shaft housing. The second ring gear is fixed inside the second planetary reduction housing. The second sun gear shaft is connected to the half-shaft gear of the differential assembly. The second planetary gear carrier is connected to the first sun gear shaft.

3. The dual planetary gear reduction drive axle as described in claim 2, characterized in that, The wheel-side reducer includes a wheel-side reducer housing. The first planetary gear reducer mechanism is installed inside the wheel-side reducer housing. The wheel-side reducer housing includes a wheel-side reducer housing body, a first wheel-side reducer housing cover, and a second wheel-side reducer housing cover. The wheel-side reducer housing body is fixedly connected to the half-shaft housing. The first wheel-side reducer housing cover is fixedly connected to the wheel-side reducer housing body. The second wheel-side reducer housing cover, the gear ring, and the wheel-side reducer housing body are fixedly connected together. The outer planetary gear carrier is provided with a shaft head. The shaft head is rotatably mounted on the first wheel-side reducer housing cover and extends out of the first wheel-side reducer housing cover via a first bearing. The inner planetary gear carrier is rotatably mounted on the second wheel-side reducer housing cover via a second bearing. The first sun gear shaft is rotatably mounted on the outer planetary gear carrier via a third bearing and rotatably mounted on the inner planetary gear carrier via a fourth bearing. One end of the first sun gear shaft passes through the mounting hole of the second wheel-side reducer housing cover and is connected to the second planetary gear carrier in a transmission connection.

4. The dual planetary gear reduction drive axle as described in claim 3, characterized in that, A first oil seal is provided between the shaft head and the first side reduction box cover.

5. The dual planetary gear reduction drive axle as described in claim 3, characterized in that, A vent plug is provided on the top of the side reduction box.

6. The dual planetary gear reduction drive axle as described in claim 3, characterized in that, The axle head is fixedly connected to a hub connecting disc.

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