Double planetary gear reduction steering drive axle

Abstract

The utility model discloses a double planetary gear reduction steering drive axle, include: central axle housing, axle housing and knuckle housing, the knuckle housing rotatory installation in axle housing, wheel edge reduction gear, wheel edge reduction gear includes first planetary gear reduction mechanism, be provided with second planetary gear reduction mechanism between central axle housing with axle housing, the power input of second planetary gear reduction mechanism with half axle gear drive connection of differential assembly, and the power output of second planetary gear reduction mechanism is connected with universal coupling transmission, the utility model discloses under the premise of not increasing wheel edge reduction gear volume has increased transmission ratio, is suitable for with high -speed gearbox matching, and high assembly accuracy, convenient installation, good maintainability, through the air plug upward exhaust, has reduced air pressure, avoided the pollution that causes to paddy field, made the conventional planetary reduction dry field bridge upgrade as water and dry dual -purpose bridge.

Description

Technical Field

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

[0002] The steering 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, achieving speed reduction and torque increase, and to steer the self-propelled machinery or vehicle through the steering mechanism; 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 steer at different speeds; and to achieve load bearing and torque transmission through the axle housing and wheels.

[0003] Planetary gear reducers, with their large speed ratios, 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 have 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 via 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, lubrication of the oil seal between the sun gear shaft and the steering knuckle housing can only be achieved by adding grease during the initial assembly phase, 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 steering drive axle, which improves the transmission ratio without increasing the volume of the wheel-side reducer, and better matches the high-speed gearbox.

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

[0011] A dual planetary gear reduction steering drive axle includes: a central axle housing, a half-shaft housing, and a steering knuckle housing. The steering knuckle housing is rotatably mounted on the 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 is also included, comprising a first planetary gear reduction mechanism. The first planetary gear reduction mechanism includes a first sun gear shaft, a first planetary gear, 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. The first planetary gear is rotatably mounted between the outer and inner planetary gear carriers. A universal coupling is connected to the first sun gear shaft. 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 universal coupling.

[0012] The second planetary gear reduction mechanism includes a second sun gear shaft, a second planetary gear, a second planetary gear carrier, a second gear ring, 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 gear ring 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 universal coupling.

[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 steering knuckle 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 universal coupling for transmission.

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

[0015] The universal joint is a cross-shaft type universal joint coupling, which includes a first universal joint fork, a second universal joint fork, and a cross shaft. The first universal joint fork is slidably connected to the first sun gear shaft via a key, and the second universal joint fork is drive-connected to the second planetary gear carrier. The first sun gear shaft is axially fixed relative to the first planetary gear carrier, and a second oil seal is provided between the second side reduction gearbox cover and the first sun gear shaft.

[0016] The second side tank cover is equipped with an oil injection nozzle.

[0017] The side reduction box is equipped with a vent plug.

[0018] The axle head is fixedly connected to a hub connecting disc.

[0019] The steering knuckle housing is rotatably mounted to the half-shaft housing via an upper kingpin and a lower kingpin.

[0020] After adopting the above technical solution, the beneficial effects of this utility model are:

[0021] The dual planetary gear reduction steering 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.

[0022] 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 steering knuckle 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 threaded connectors, making installation convenient. The inner hole of the inner planetary gear carrier and The outer diameter can be machined in one clamping operation and the fourth and second bearings can be installed separately. The inner hole and outer diameter of the outer planetary gear carrier can be machined in one clamping operation 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 and inner planetary gear carriers. 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 easily guaranteed, which improves the assembly accuracy.

[0023] 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.

[0024] In this invention, the universal joint is a cross-shaft type universal joint coupling, which includes a first universal joint fork, a second universal joint fork, and a cross shaft. The first universal joint fork is slidably connected to the first sun gear shaft via a key, and the second universal joint fork is drive-connected to the second planetary gear carrier. The first sun gear shaft is axially fixed relative to the first planetary gear carrier, and a second oil seal is provided between the second side reducer housing cover and the first sun gear shaft. The sealing motion of the second oil seal and the first sun gear shaft is changed from the reciprocating pull-and-rotate motion of the prior art to rotation only without pull-and-rotate, improving the durability and service life of the oil seal. Simultaneously, due to the adoption of the side reducer housing structure, its internal space is increased. The second side reducer housing cover is equipped with an oil injection nozzle. By disassembling the connecting piece between the side reducer housing and the steering knuckle housing and removing the wheel-side reducer, lubrication can be provided to the key connection between the universal joint fork and the sun gear shaft through the oil injection nozzle. Therefore, subsequent maintenance and repair of the wheel-side reducer are possible, resulting in good maintainability.

[0025] In this invention, the side reduction gearbox does not rotate relative to the half-shaft housing. Therefore, 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, which reduces the air pressure and solves 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

[0026] Figure 1 This is a longitudinal sectional view of an embodiment of the dual planetary gear reduction steering drive axle of this utility model;

[0027] In the picture:

[0028] 10. Hub connecting disc; 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; 20. Second oil seal; 21. Side reduction gearbox housing; 22. First side reduction gearbox cover; 23. Second side reduction gearbox cover; 24. Oil filler nozzle; 25. Breather plug; 26. Drain plug; 31. Steering knuckle housing; 32. Upper kingpin; 33. Lower kingpin; 41. First universal joint fork; 42. Second universal joint fork; 43. Cross shaft; 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 transmission bevel gear. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Example

[0031] like Figure 1 As shown, a dual planetary gear reduction steering drive axle has a steering knuckle housing 31 rotatably mounted on a half-shaft housing 5 via an upper kingpin 32 and a lower kingpin 33. A differential assembly 8, which is drively connected to the input bevel gear shaft 91, is housed within the central axle housing 7. The differential assembly 8 includes a differential housing 81 and a half-shaft gear 82.

[0032] 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 universal coupling. 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 universal coupling.

[0033] 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.

[0034] The dual planetary gear reduction steering 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.

[0035] In this embodiment, the wheel-side reducer further 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 21, a first wheel-side reducer housing cover 22, and a second wheel-side reducer housing cover 23. The wheel-side reducer housing body 21 is fixedly connected to the steering knuckle housing 31. The first wheel-side reducer housing cover 22 is fixedly connected to the wheel-side reducer housing body 21. The second wheel-side reducer housing cover 23A, the gear ring 13, and the wheel-side reducer housing 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 wheel-side reducer housing cover 22 and extends out of the first wheel-side reducer housing cover 22 via a first bearing 14. A first oil seal 19 is provided between the shaft head and the first wheel-side reducer housing 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 universal coupling 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.

[0036] 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.

[0037] 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.

[0038] In this embodiment, the universal joint is a cross-shaft type universal joint coupling, which includes a first universal joint fork 41, a second universal joint fork 42, and a cross shaft 43. The first universal joint fork 41 is slidably connected to the first sun gear shaft 11 via a key, and the second universal joint fork 42 is drive-connected to the second planetary gear carrier 64. The first sun gear shaft 11 is axially fixed relative to the first planetary gear carrier. A second oil seal 20 is provided between the second side reducer cover 23 and the first sun gear shaft 11. The second side reducer cover 23 is provided with an oil filling nozzle 24. The sealing movement of the second oil seal 20 and the first sun gear shaft 11 is changed from the reciprocating pull-and-rotate motion of the prior art to rotation only without pull-and-rotate, which improves the durability and service life of the oil seal. Meanwhile, due to the adoption of the side reduction gearbox structure, its internal space is increased, which makes it convenient to install the oil injection nozzle 24 on the second side reduction gearbox cover 23. By disassembling the connecting piece between the side reduction gearbox body 21 and the steering knuckle housing 31 and removing the wheel-side reducer, lubrication can be provided to the key connection between the first universal joint fork 41 and the sun gear shaft 11 through the oil injection nozzle 24. Therefore, the wheel-side reducer can be subsequently maintained and repaired, and has good maintainability.

[0039] 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.

[0040] 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 steering drive axle, comprising: The central axle housing, the half-shaft housing, and the steering knuckle housing are provided. The steering knuckle housing is rotatably mounted on the half-shaft housing. A differential assembly that is connected to the input bevel gear shaft is provided inside the central axle housing. A wheel-side reducer, comprising a first planetary gear reduction mechanism, the first planetary gear reduction mechanism including a first sun gear shaft, first planetary gears, a first planetary gear carrier, and a first ring gear, the first planetary gear carrier including an outer planetary gear carrier and an inner planetary gear carrier connected together, the first planetary gears being rotatably mounted between the outer planetary gear carrier and the inner planetary gear carrier, and the first sun gear shaft being connected to a universal coupling; 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 universal coupling.

2. The dual planetary gear reduction steering 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 universal coupling.

3. The dual planetary gear reduction steering 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 steering knuckle 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 universal coupling for transmission.

4. The dual planetary gear reduction steering 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 steering drive axle as described in claim 3, characterized in that, The universal joint is a cross-shaft type universal joint coupling, which includes a first universal joint fork, a second universal joint fork, and a cross shaft. The first universal joint fork is slidably connected to the first sun gear shaft via a key, and the second universal joint fork is drive-connected to the second planetary gear carrier. The first sun gear shaft is axially fixed relative to the first planetary gear carrier, and a second oil seal is provided between the second side reduction gearbox cover and the first sun gear shaft.

6. The dual planetary gear reduction steering drive axle as described in claim 5, characterized in that, The second side tank cover is equipped with an oil injection nozzle.

7. The dual planetary gear reduction steering drive axle as described in claim 3, characterized in that, The side reduction box is equipped with a vent plug.

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

9. The dual planetary gear reduction steering drive axle as described in claim 3, characterized in that, The steering knuckle housing is rotatably mounted to the half-shaft housing via an upper kingpin and a lower kingpin.

Images