Hub reduction gear

Abstract

The hub reduction gear comprises a side reduction box provided with a planetary gear reduction mechanism, the side reduction box comprises a side reduction box body, a first side reduction box cover and a second side reduction box cover, the side reduction box body is fixedly connected with a steering knuckle shell, a gear ring is fixed in the side reduction box body, an outer side planet carrier is provided with a shaft head, and the shaft head is provided with a first gear ring and a second gear ring; the shaft head is rotationally installed on the first edge reduction box cover through a first bearing, the inner side planet carrier is rotationally installed on the second edge reduction box cover through a second bearing, and the sun gear shaft is rotationally installed on the outer side planet carrier through a third bearing and rotationally installed on the inner side planet carrier through a fourth bearing. According to the invention, the assembly precision is high, the installation is convenient, the maintainability is good, the ventilation plug is used for exhausting air upwards, the air pressure is reduced, the pollution to a paddy field is avoided, and a conventional planetary speed reduction dry field bridge is upgraded to an amphibious bridge.

Description

Technical Field

[0001] This invention relates to the field of wheel-side reducer technology, and more specifically to a wheel-side reducer used on a drive axle or steering drive axle. Background Technology

[0002] The drive axle or steering drive axle is located at the end of the power transmission system of self-propelled operating 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., and then drive the wheels, thereby achieving speed reduction and torque increase; the steering drive axle enables the self-propelled operating machinery or vehicle to steer 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 have a large speed ratio, compact structure, and high transmission torque, and are often used as wheel-side reducers. A planetary gear reducer typically includes a sun gear shaft, planet carriers, and a ring gear. The planet carrier is fixedly connected to the wheel hub, the wheel hub is rotatably mounted on the steering knuckle housing via tapered roller bearings, and the ring gear is fixed to the steering knuckle housing via threaded connections. However, this structure has 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, in the steering drive axle, on the one hand, the wheel hub is rotated and mounted on the steering knuckle housing, and a dynamic seal needs to be set between the wheel 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 pollution will cause pollution to 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 and cannot be used for subsequent maintenance. Furthermore, as the oil temperature and air pressure increase within the planetary reduction mechanism, oil leakage is more likely at the seals of various components. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a wheel-side reducer to improve assembly accuracy and ease of installation.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A wheel-side reducer includes: a planetary gear reduction mechanism, the planetary gear reduction mechanism including a sun gear shaft, planet gears, planet carriers, and a ring gear, the planet carrier including an outer planet carrier and an inner planet carrier connected together, the planet gears being rotatably mounted between the outer planet carrier and the inner planet carrier; the wheel-side reducer further includes a wheel-side reducer housing, the planetary gear reduction mechanism being installed inside the wheel-side reducer housing, the wheel-side reducer housing including a wheel-side reducer housing body, a first wheel-side reducer housing cover, and a second wheel-side reducer housing cover, the first wheel-side reducer housing cover being fixedly attached to the wheel-side reducer housing body. The second side reduction gearbox cover, the gear ring, and the side reduction gearbox body are fixedly connected together. The outer planetary gear carrier is provided with a shaft head, which is rotatably mounted on the first side reduction gearbox cover and extends out of the first side reduction gearbox cover via a first bearing. The inner planetary gear carrier is rotatably mounted on the second side reduction gearbox cover via a second bearing. The 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 sun gear shaft passes through the mounting hole of the second side reduction gearbox cover.

[0011] A first oil seal is provided between the shaft head and the first side reduction box cover.

[0012] The sun gear shaft is axially fixed relative to the planetary gear carrier, and a second oil seal is provided between the second side reducer cover and the sun gear shaft.

[0013] The second side tank cover is equipped with an oil injection nozzle.

[0014] The side reduction box is equipped with a vent plug.

[0015] The axle head is fixedly connected to a hub connecting disc.

[0016] After adopting the above technical solution, the beneficial effects of the present invention are:

[0017] The wheel-side reducer disclosed in this invention has a planetary gear reduction mechanism installed inside the wheel-side reducer housing. The wheel-side reducer housing includes a housing body, a first cover, and a second cover. The first cover is fixedly connected to the housing body. The second cover, the gear ring, and the housing body are fixedly connected together. When driving the axle or steering the axle, the wheel-side reducer housing does not rotate relative to the half-shaft housing. The gear ring is directly fixed inside the housing, eliminating the need for a threaded connection to the steering knuckle housing, thus facilitating installation. The inner planetary gear carrier... The inner hole and outer circle can be machined in one clamping and then the fourth and second bearings can be installed respectively. The inner hole and outer circle of the outer planetary gear carrier can also be machined in one clamping and then the third and first bearings can be installed respectively. The third and fourth bearings are used to support the 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 reducer cover. The second bearing is used to support the inner planetary gear carrier on the second side reducer cover. Therefore, the coaxiality of the sun gear shaft, planetary gear carrier and gear ring is easily guaranteed, which improves the assembly accuracy.

[0018] In this invention, the outer planetary gear carrier is provided with a shaft head, which is rotatably mounted on the first side reducer cover and extends out of the first side reducer 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.

[0019] This invention relates to a steering drive axle where the sun gear shaft is slidably connected to one universal joint fork of the universal coupling via a key. The sun gear shaft is axially fixed relative to the planetary gear carrier. A second oil seal is provided between the second side reducer housing cover and the sun gear shaft. The sealing movement of the second oil seal and the sun gear shaft is changed from the reciprocating pull-and-rotate motion of the prior art to rotation only, 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.

[0020] In this invention, the side reduction gearbox does not rotate relative to the half-shaft housing, 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

[0021] Figure 1 This is a longitudinal sectional view of Embodiment 1 of the present invention, in which the wheel-side reducer is applied to a steering drive axle;

[0022] Figure 2 This is a longitudinal sectional view of Embodiment 2 of the present invention, in which the wheel-side reducer is applied to the drive axle;

[0023] In the picture:

[0024] 10. Hub connecting plate; 11A. Sun gear shaft; 11B. Sun gear shaft; 12A. Outer planetary gear carrier; 12B. Inner planetary gear carrier; 13. Ring gear; 14. First bearing; 15. Second bearing; 16. Third bearing; 17. Fourth bearing; 18. Planetary gears; 19. First oil seal; 20. Second oil seal; 21. Side reduction gearbox; 22. First side reduction gearbox cover; 23A. Second side reduction gearbox cover; 23B. 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; 5A. Half shaft housing; 5B. Half shaft housing. Detailed Implementation

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

[0026] Example 1

[0027] like Figure 1 As shown, a steering drive axle has a steering knuckle housing 31 rotatably mounted on a half-shaft housing 5A via an upper kingpin 32 and a lower kingpin 33.

[0028] The wheel-side reducer includes a planetary gear reduction mechanism, which comprises a sun gear shaft 11A, planetary gears 18, planetary gear carriers, and a ring gear 13. The planetary gear carrier includes an outer planetary gear carrier 12A and an inner planetary gear carrier 12B connected together. The planetary gears 18 are rotatably mounted between the outer planetary gear carrier 12A and the inner planetary gear carrier 12B. The planetary gear reduction mechanism has a large speed ratio, compact structure, and high transmission torque.

[0029] In this embodiment, the wheel-side reducer further includes a wheel-side reducer housing. The planetary gear reduction 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 23A. 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 23A via the second bearing 15. The sun gear shaft 11A 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 sun gear shaft 11A passes through the mounting hole of the second side reduction gearbox cover 23A 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.

[0030] The above structure ensures that the reducer box does not rotate relative to the half-shaft housing during operation. The 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 sun gear shaft 11A 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 23A. Therefore, the coaxiality of the sun gear shaft 11A, planetary gear carrier, and gear ring 13 is easily guaranteed, improving assembly accuracy.

[0031] 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.

[0032] 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 sun gear shaft 11A via a key. The sun gear shaft 11A is axially fixed relative to the planetary gear carrier. A second oil seal 20 is provided between the second side reducer cover 23A and the sun gear shaft 11A. The second side reducer cover 23A is provided with an oil injection nozzle 24. The sealing movement of the second oil seal 20 and the sun gear shaft 11A 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 grease nipple 24 on the second side reduction gearbox cover 23A, remove the connecting piece between the side reduction gearbox body 21 and the steering knuckle housing 31, remove the wheel-side reducer, and lubricate the key connection between the first universal joint fork 41 and the sun gear shaft 11A through the grease nipple 24. Therefore, the wheel-side reducer can be subsequently maintained and repaired, and has good maintainability.

[0033] 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 dual-purpose bridge for both dry and paddy fields.

[0034] Example 2

[0035] like Figure 2 As shown, a drive axle includes a wheel-side reducer mounted on a half-shaft housing 5B. The wheel-side reducer comprises a planetary gear reduction mechanism, which includes a sun gear shaft 11B, planet gears 18, planet carriers, and a ring gear 13. The planet carrier includes an outer planet carrier 12A and an inner planet carrier 12B connected together. The planet gears 18 are rotatably mounted between the outer planet carrier 12A and the inner planet carrier 12B. The planetary gear reduction mechanism has a large speed ratio, compact structure, and high transmission torque.

[0036] In this embodiment, the wheel-side reducer further includes a side reduction gearbox. The 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 23B. The side reduction gearbox body 21 is fixedly connected to the half-shaft housing 5B. The first side reduction gearbox cover 22 is fixedly connected to the side reduction gearbox body 21. The second side reduction gearbox cover 23B, 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 23B via the second bearing 15. The sun gear shaft 11B 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 sun gear shaft 11B protrudes through the mounting hole of the second side reduction gearbox cover 23B. 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, the third bearing 16, and the fourth bearing 17 are preferably ball bearings.

[0037] The above structure ensures that the reducer box does not rotate relative to the half-shaft housing during operation. The gear ring 13 is directly fixed inside the reducer box body 21, without needing to be connected to the half-shaft housing 5B 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 then the fourth bearing 17 and the second bearing 15 are installed respectively. The inner hole and outer circle of the outer planetary gear carrier 12A can be machined in one clamping and then the third bearing 16 and the first bearing 14 are installed respectively. The third bearing 16 and the fourth bearing 17 are used to support the sun gear shaft 11B 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 23B. Therefore, the coaxiality of the sun gear shaft 11B, the planetary gear carrier, and the gear ring 13 is easily guaranteed, improving assembly accuracy.

[0038] 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.

[0039] In this embodiment, the sun gear shaft 11B is axially fixed relative to the planetary gear carrier.

[0040] 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.

[0041] This invention is not limited to the above embodiments. All improvements made based on the concept, principle, structure and method of this invention shall fall within the protection scope of this invention.

Claims

1. A wheel side reducer, comprising: a planetary gear reduction mechanism, the planetary gear reduction mechanism comprising a sun gear shaft, a planet wheel, a planet wheel carrier and a ring gear, the planet wheel carrier comprising an outer planet wheel carrier and an inner planet wheel carrier connected together, the planet wheel being rotatably mounted between the outer planet wheel carrier and the inner planet wheel carrier; characterized in that, the wheel side reducer further comprises a side reduction box, the planetary gear reduction mechanism being mounted in the side reduction box, the side reduction box comprising a side reduction box body, a first side reduction box cover and a second side reduction box cover, the first side reduction box cover being fixedly connected with the side reduction box body, the second side reduction box cover, the ring gear and the side reduction box body being fixedly connected together, the outer planet wheel carrier being provided with a shaft head, the shaft head being rotatably mounted on the first side reduction box cover and extending out of the first side reduction box cover through a first bearing, the inner planet wheel carrier being rotatably mounted on the second side reduction box cover through a second bearing, the sun gear shaft being rotatably mounted on the outer planet wheel carrier through a third bearing and rotatably mounted on the inner planet wheel carrier through a fourth bearing, one end of the sun gear shaft extending out of a mounting hole of the second side reduction box cover.

2. The hub reduction of claim 1, wherein, A first oil seal is arranged between the shaft head and the first side reduction box cover.

3. The hub reduction of claim 1, wherein, The sun gear shaft is axially fixed relative to the planet wheel carrier, and a second oil seal is arranged between the second side reduction box cover and the sun gear shaft.

4. The hub reduction of claim 3, wherein, The second side reduction box cover is provided with an oil injection nozzle.

5. The hub reduction of claim 1, wherein, The side reduction box body is provided with a vent plug.

6. The hub reduction of claim 1, wherein, The shaft head is fixedly connected with a hub connecting disc.

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