Tail end transmission device of large tractor

Abstract

A tail end transmission device of a large tractor belongs to the field of tractors and comprises a tail end shell, the front portion of the tail end shell is connected with a first-stage planetary reduction mechanism and a second-stage planetary reduction mechanism, the first-stage planetary reduction mechanism and the second-stage planetary reduction mechanism share the same gear ring, the gear ring is fixedly connected with the tail end shell, and inner teeth of the front section of the gear ring are meshed with a first-stage planetary gear. Inner teeth of the rear section of the gear ring are meshed with the second-stage planet wheel, the number of inner teeth of the front section of the gear ring is the same as that of the inner teeth of the rear section of the gear ring, the half shaft is connected with the first-stage planet speed reducing mechanism through the first-stage sun wheel, the first-stage planet carrier is connected with the second-stage planet speed reducing mechanism through the second-stage sun wheel, and the second-stage planet carrier is connected with one end of the driving shaft. The other end of the driving shaft is connected with a driving hub to drive tires to rotate. According to the device, the total reduction ratio is increased, the transmission torque of each transmission part is reasonably distributed, the tail end transmission boundary dimension is small, three first-stage planet gears and six second-stage planet gears are adopted on one side, the tail end transmission strength is improved, and the reliability requirement of large-scale operation of a large tractor is met.

Description

Technical Field

[0001] The utility model belongs to the field of tractors, relates to a transmission device, and particularly relates to an end transmission device of a large tractor. Background Art

[0002] As is well known, the end transmission device of a tractor is a key component for power transmission. It is the final speed reduction device of the tractor transmission system and is symmetrically arranged on both sides of the rear axle of the tractor. The end transmission device of the tractor can effectively transmit the power generated by the engine to the two rear drive wheels, enabling the tractor to drive normally and perform various operations.

[0003] There are generally two transmission methods for the existing end transmission devices of tractors. One is to use a pair of external meshing gears for transmission; the other is to use a single-stage planetary mechanism for transmission. Both of these transmission methods have the following defects: First, the end transmission reduction ratio is relatively small, resulting in the need to increase the reduction ratios of the main and auxiliary transmissions and the central transmission of the tractor, thereby increasing the transmitted torque of these components and causing their parts to be easily damaged due to overload in the early stage, that is, the load distribution of the components of the entire transmission system is unreasonable; Second, the external dimensions of the end transmission are relatively large, resulting in the need to correspondingly increase the structures on both sides of the tractor rear axle, thereby affecting the arrangement of other components, that is, the overall machine design is not very reasonable. Especially in Xinjiang and Northeast regions of China, in order to ensure national food security, large-scale tractor operations are required. However, the above defects have certain impacts on the use of large tractors in these regions. Therefore, it is necessary to provide a new technical solution for the end transmission device of a large tractor. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an end transmission device of a large tractor that is compact in structure, convenient to operate, safe and reliable, and can effectively overcome the above defects.

[0005] The above object of the utility model can be achieved by the following technical solutions: An end transmission device for a large tractor, comprising: an end housing, in which a first-stage planetary reduction mechanism and a second-stage planetary reduction mechanism are supported at the front part. The first-stage planetary reduction mechanism includes: a first-stage sun gear, first-stage planetary gears, a ring gear, first-stage planetary gear shafts, and a first-stage planetary carrier; the first-stage sun gear meshes with the first-stage planetary gears, the first-stage planetary gears mesh with the inner teeth of the front section of the ring gear, the first-stage planetary gears are sleeved on the first-stage planetary gear shafts through needle bearings, and the first-stage planetary gear shafts are supported on the first-stage planetary carrier; the second-stage planetary reduction mechanism includes a second-stage sun gear, second-stage planetary gears, a ring gear, second-stage planetary gear shafts, and a second-stage planetary carrier, the second-stage sun gear meshes with the second-stage planetary gears, the second-stage planetary gears mesh with the inner teeth of the rear section of the ring gear, the second-stage planetary gears are sleeved on the second-stage planetary gear shafts through needle bearings, and the second-stage planetary gear shafts are supported on the second-stage planetary carrier; the half shaft is connected to the first-stage planetary reduction mechanism through the first-stage sun gear, the first-stage planetary carrier is connected to the second-stage planetary reduction mechanism through the second-stage sun gear, the second-stage planetary carrier is connected to one end of the drive shaft, and the other end of the drive shaft is connected to the drive hub.

[0006] The first-stage planetary reduction mechanism adopts three first-stage planetary gears, and the three first-stage planetary gears are evenly distributed around the first-stage sun gear on the first-stage planetary carrier.

[0007] The second-stage planetary reduction mechanism adopts six second-stage planetary gears, and the six second-stage planetary gears are divided into three groups with two in each group, and are evenly distributed around the second-stage sun gear on the second-stage planetary carrier.

[0008] The first-stage planetary reduction mechanism and the second-stage planetary reduction mechanism share the same ring gear. The inner teeth of the ring gear are divided into the inner teeth of the front section and the inner teeth of the rear section. The number of teeth of the inner teeth of the front section and the inner teeth of the rear section of the ring gear is the same, and the ring gear is fixedly connected to the end housing.

[0009] The drive hub and the drive shaft are supported on the end housing by two bearings. After the utility model adopts the above technical solutions, the following beneficial effects can be achieved: 1. By connecting the first-stage planetary reduction mechanism and the second-stage planetary reduction mechanism in series, the total reduction ratio of the end transmission device reaches 12.15. Since the total reduction ratio of the end transmission device increases, the reduction ratios of the main and auxiliary transmissions and the central transmission are effectively reduced, that is, the torque transmission distribution of each transmission component is reasonable, and the design requirements of large tractors can be met; 2. The outer dimension of the end transmission device is small, which does not affect the reasonable arrangement of other components of the tractor rear axle, that is, the design of the overall technical performance parameters of the tractor is reasonable; 3. By using an optimized and innovative design method, three first-stage planetary gears and six second-stage planetary gears are adopted, that is, 9 planetary gears are used on one side, and the two-stage planetary reduction mechanisms share the same ring gear, and the number of teeth of the inner teeth of the front section and the inner teeth of the rear section of the ring gear is the same, which greatly improves the strength of the end transmission and meets the reliability requirements of large-scale operation of large tractors. Description of the Drawings

[0010] Figure 1 Schematic structural diagram of the final drive device of a large tractor of the present utility model;

[0011] Figure 2 Schematic distribution structure diagram of the three first-stage planet gears of the final drive device of a large tractor of the present utility model;

[0012] Figure 3 Schematic distribution structure diagram of the six second-stage planet gears of the final drive device of a large tractor of the present utility model.

[0013] In the figure: A. First-stage planetary reduction mechanism, B. Second-stage planetary reduction mechanism, 1. Final housing, 2. First-stage sun gear, 3. First-stage planet gear, 4. Ring gear, 5. First-stage planet gear shaft, 6. First-stage planet carrier, 7. Second-stage sun gear, 8. Second-stage planet gear, 9. Second-stage planet gear shaft, 10. Second-stage planet carrier, 11. Half shaft, 12. Drive shaft, 13. Drive hub. Specific embodiments

[0014] The following further describes the present utility model in conjunction with the appended Figures 1 - 3 drawings and embodiments.

[0015] As Figure 1 shown, a final drive device of a large tractor includes: a final housing 1, and the front part of the final housing 1 is connected to a first-stage planetary reduction mechanism A and a second-stage planetary reduction mechanism B. The first-stage planetary reduction mechanism A includes: a first-stage sun gear 2, first-stage planet gears 3, a ring gear 4, first-stage planet gear shafts 5, and a first-stage planet carrier 6; the second-stage planetary reduction mechanism B includes: a second-stage sun gear 7, second-stage planet gears 8, a ring gear 4, second-stage planet gear shafts 9, and a second-stage planet carrier 10; the half shaft 11 is connected to the first-stage sun gear 2 through a spline, the first-stage sun gear 2 meshes with the first-stage planet gears 3, the first-stage planet gears 3 mesh with the inner teeth of the front section of the ring gear 4, the first-stage planet gears 3 are sleeved on the first-stage planet gear shafts 5 through needle bearings, the first-stage planet gear shafts 5 are supported on the first-stage planet carrier 6, the first-stage planet carrier 6 is connected to the second-stage sun gear 7 through a spline, the second-stage sun gear 7 meshes with the second-stage planet gears 8, the second-stage planet gears 8 mesh with the inner teeth of the rear section of the ring gear 4, the second-stage planet gears 8 are sleeved on the second-stage planet gear shafts 9 through needle bearings, the second-stage planet gear shafts 9 are supported on the second-stage planet carrier 10, the second-stage planet carrier 10 is connected to one end of the drive shaft 12 through a spline, the other end of the drive shaft 12 is connected to the drive hub 13, and the drive hub 13 and the drive shaft 12 are supported on the final housing 1 by two bearings. One set of the final drive devices is symmetrically arranged on each side of the left and right of the tractor rear axle.

[0016] The first-stage planetary reduction mechanism A and the second-stage planetary reduction mechanism B share the same ring gear 4. The inner teeth of the ring gear 4 are divided into front and rear sections, and the number of teeth of the inner teeth of the front section and the rear section of the ring gear 4 is the same. The ring gear 4 is fixedly connected to the final housing 1 through a set of bolts.

[0017] As Figure 2 shown, the first-stage planetary reduction mechanism A uses three first-stage planetary gears 3, and the three first-stage planetary gears 3 are evenly distributed around the first-stage sun gear 2 on the first-stage planetary carrier 6; as Figure 3 shown, the second-stage planetary reduction mechanism B uses six second-stage planetary gears 8. The six second-stage planetary gears 8 are divided into three groups with two in each group and are evenly distributed around the second-stage sun gear 7 on the second-stage planetary carrier 10.

[0018] The power of the engine is transmitted from the gearbox to the rear axle differential and then to the half shaft 11. The half shaft 11 transmits the power into the first-stage sun gear 2. The first-stage sun gear 2 drives the three first-stage planetary gears 3 to rotate selflessly and at the same time roll along the inner teeth of the front section of the ring gear 4. That is, the three first-stage planetary gears 3, the three first-stage planetary gear shafts 5, and the first-stage planetary carrier 6 rotate around the first-stage sun gear 2 together. The first-stage planetary carrier 6 outputs power to the second-stage sun gear 7. The second-stage sun gear 7 drives the six second-stage planetary gears 8 to rotate selflessly and at the same time roll along the inner teeth of the rear section of the ring gear 4. That is, the six second-stage planetary gears 8, the six second-stage planetary gear shafts 9, and the second-stage planetary carrier 10 rotate around the second-stage sun gear 7 together. The second-stage planetary carrier 10 outputs power to the drive shaft 12. The drive shaft 12 transmits the power to the drive hub 13, and the drive hub 13 drives the tire to rotate.

[0019] The utility model adopts a series connection of the first-stage planetary reduction mechanism and the second-stage planetary reduction mechanism, effectively reducing the reduction ratios of the main and auxiliary transmissions and the central transmission, and the transmission torque distribution of each transmission component is reasonable; the outer dimension of the final drive device is small and does not affect the reasonable arrangement of other components of the tractor rear axle; three first-stage planetary gears and six second-stage planetary gears are adopted, and the two-stage planetary reduction mechanisms share a ring gear, greatly improving the strength of the final drive.

[0020] In practical applications, the utility model is not limited to the situation described in this example. All technical solutions and improvements that do not deviate from the substantial content of the utility model shall fall within the protection scope of the claims of the utility model.

Claims

1. An end drive device for a large tractor, comprising: The end housing (1), the front part of the end housing (1) supports a first-stage planetary reduction mechanism (A) and a second-stage planetary reduction mechanism (B). The first-stage planetary reduction mechanism (A) includes: a first-stage sun gear (2), first-stage planetary gears (3), a ring gear (4), first-stage planetary gear shafts (5), and a first-stage planet carrier (6); characterized in that: the first-stage sun gear (2) meshes with the first-stage planetary gears (3), the first-stage planetary gears (3) mesh with the inner teeth of the front section of the ring gear (4), the first-stage planetary gears (3) are sleeved on the first-stage planetary gear shafts (5) through needle bearings, and the first-stage planetary gear shafts (5) are supported on the first-stage planet carrier (6); the second-stage planetary reduction mechanism (B) includes a second-stage sun gear (7), second-stage planetary gears (8), the ring gear (4), second-stage planetary gear shafts (9), and a second-stage planet carrier (10). The second-stage sun gear (7) meshes with the second-stage planetary gears (8), the second-stage planetary gears (8) mesh with the inner teeth of the rear section of the ring gear (4), the second-stage planetary gears (8) are sleeved on the second-stage planetary gear shafts (9) through needle bearings, and the second-stage planetary gear shafts (9) are supported on the second-stage planet carrier (10); the half shaft (11) is connected to the first-stage planetary reduction mechanism (A) through the first-stage sun gear (2), the first-stage planet carrier (6) is connected to the second-stage planetary reduction mechanism (B) through the second-stage sun gear (7), the second-stage planet carrier (10) is connected to one end of the drive shaft (12), and the other end of the drive shaft (12) is connected to the drive wheel hub (13); the first-stage planetary reduction mechanism (A) uses three first-stage planetary gears (3), and the three first-stage planetary gears (3) are evenly distributed around the first-stage sun gear (2) on the first-stage planet carrier (6); the second-stage planetary reduction mechanism (B) uses six second-stage planetary gears (8), and the six second-stage planetary gears (8) are divided into three groups with two in each group and are evenly distributed around the second-stage sun gear (7) on the second-stage planet carrier (10).

2. The end drive device of a large tractor according to claim 1, characterized in that: The first-stage planetary reduction mechanism (A) and the second-stage planetary reduction mechanism (B) share the same ring gear (4). The inner teeth of the ring gear (4) are divided into the inner teeth of the front section and the inner teeth of the rear section. The number of teeth of the inner teeth of the front section and the inner teeth of the rear section of the ring gear (4) is the same, and the ring gear (4) is fixedly connected to the end housing (1).

3. The end drive device of a large tractor according to claim 1, characterized in that: The drive wheel hub (13) and the drive shaft (12) are supported on the end housing (1) by two bearings.

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