Steering control transmission system of crawler tractor

Abstract

The invention discloses a steering control transmission system of a crawler tractor, which comprises a fuel engine, a gearbox assembly, a walking speed change assembly and a steering control assembly, and is characterized in that the gearbox assembly comprises a first gear shifting assembly and a second gear shifting assembly; the first gear switching assembly is in transmission connection with the walking speed change assembly through the steering control assembly and inputs first power to the walking speed change assembly, and the second gear switching assembly is in transmission connection with the walking speed change assembly and inputs second power to the walking speed change assembly. Walking half shafts on the left side and the right side of the walking speed change assembly generate a rotating speed difference under the superposition action of the first power and the second power, and tracks on the two sides are driven to achieve steering. The steering operation habit is better met in the steering operation process, in-situ turning and steering can be achieved at a low speed, large-radius steering is achieved at a high speed, and the use safety is improved.

Description

Technical Field

[0001] The invention relates to the technical field of transmission, and in particular to a steering control transmission system for a crawler tractor. Background Art

[0002] The steering transmission of the existing differential steering crawler tractor usually adopts the dual power flow confluence technology of the planetary reduction mechanism, which is specifically: two left and right planetary reduction mechanisms are set in the rear axle housing, and the travel power flow is input through the sun gear of the planetary reduction mechanism, and the steering power flow is input through the ring gear of the planetary reduction mechanism. After the two power flows converge at the planetary carrier, differential output is realized, and then the left and right half shafts are driven to realize differential steering. In the prior art, the travel power flow is input to the sun gear of the planetary reduction mechanism after the gearbox completes the switching of different gears; the steering power flow is converted from the mechanical energy on the clutch shaft into hydraulic energy by a hydraulic pump arranged on the clutch shaft, and then the hydraulic motor is driven to rotate, and the steering power is input to the ring gear of the planetary reduction mechanism. In the above layout, because the clutch shaft is directly connected to the power shaft of the fuel engine through the clutch, its rotation direction is fixed, that is, the rotation direction of the input shaft of the hydraulic pump remains unchanged; however, after the travel power completes the switching of different gears through the gearbox assembly, there are power outputs in two directions: forward (forward rotation) and backward (reverse rotation). In the above situation, when the tractor is turning, the steering direction and the actual movement direction can only meet the same direction in one situation (forward or backward). For example, when the forward direction is met, the steering wheel is operated to the left, and the tractor turns left; when backward, the steering wheel is operated to the left, and the tractor reverses to the right. This causes the steering wheel operation direction to be inconsistent with the actual backward direction of the tractor when backward, which is easy to cause safety accidents. Vice versa. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a steering control transmission system for a crawler tractor to solve the problem that the steering control direction in the prior art is inconsistent with the actual movement direction, which easily causes safety accidents.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a crawler tractor steering control transmission system, including a fuel engine, a gearbox assembly, a travel speed change assembly and a steering control assembly, the fuel engine inputs power to the gearbox assembly through a clutch shaft, the gearbox assembly includes a first gear shift assembly and a second gear shift assembly, the first gear shift assembly is connected to the clutch shaft in a driving manner, wherein the first gear shift assembly is used for switching between a forward gear and a reverse gear, and the second gear shift assembly is used for switching between different speed gears; The first gear switching assembly is connected to the travel speed change assembly through the steering control assembly. The steering control assembly can input a first power to the travel speed change assembly under the drive of the first gear switching assembly. The first power includes a forward steering power and a reverse steering power corresponding to the gear of the first gear switching assembly. The second gear switching assembly is connected to the travel speed change assembly to input a second power to the travel speed change assembly. The left and right travel half shafts of the travel speed change assembly generate a speed difference under the superposition of the first power and the second power, and drive the tracks on both sides to achieve steering.

[0005] As an optimization, the first gear shifting assembly includes a speed shifting driven shaft, on which a reverse gear driven gear, a forward gear driven gear and a hydraulic pump power input driving gear are provided. When the forward gear is selected, the forward gear driven gear meshes with the forward gear driving gear arranged on the clutch shaft. When the reverse gear is selected, the reverse gear driven gear meshes with the reverse gear driving gear arranged on the clutch shaft through a reverse gear transition gear arranged on the reverse gear transition shaft, so that the rotation direction of the hydraulic pump power input driving gear corresponds to the gear position of the first gear shifting assembly, and the hydraulic pump power input driving gear is transmission connected to the steering control assembly.

[0006] As an optimization, the steering control assembly includes a hydraulic pump and a hydraulic motor connected thereto. The hydraulic pump is installed on a hydraulic pump speed change assembly and is connected to the hydraulic pump power input driving gear transmission. The hydraulic motor is connected to the travel speed change assembly through a steering gear set and inputs steering power with opposite rotation directions to the left and right travel half-axles of the travel speed change assembly.

[0007] As an optimization, the hydraulic pump speed change assembly is provided with a hydraulic pump power input transition shaft, and the hydraulic pump power input transition shaft is provided with a hydraulic pump power input transition gear meshing with the hydraulic pump power input driving gear, and the hydraulic pump power input transition gear is meshed with the hydraulic pump power input driven gear arranged on the input shaft of the hydraulic pump.

[0008] As an optimization, the hydraulic pump is provided with a reversing handle, and by turning the reversing handle, the hydraulic pump can drive the hydraulic motor to switch between forward rotation, stop rotation and reverse rotation.

[0009] As an optimization, the reversing gear set includes a steering driving gear arranged on the output shaft of the hydraulic motor, and a steering driven gear meshing with the steering driving gear. The steering driven gear is transmission-connected to the left traveling half-shaft of the traveling speed change assembly, and is transmission-connected to the right traveling half-shaft of the traveling speed change assembly through a steering transition gear arranged on the steering transition shaft, so that the hydraulic motor inputs steering power with opposite rotation directions to the left and right traveling half-shafts of the traveling speed change assembly.

[0010] As an optimization, the travel speed change assembly includes a sun gear shaft, on which a large bevel gear is provided, the large bevel gear is meshed with a small bevel gear, and the small bevel gear is transmission connected to the second gear switching assembly; the two ends of the sun gear shaft are respectively connected to the left planetary speed gear set and the right planetary speed gear set, which are respectively used to drive the left half shaft and the right half shaft connected to the left and right tracks respectively, wherein the left planetary speed gear set is transmission connected to the steering driven gear, and the right planetary speed gear set is transmission connected to the steering transition gear.

[0011] As an optimization, the left planetary speed change gear set includes a left sun gear arranged on the sun gear shaft, and a left planet carrier, the left planet carrier is provided with a left planet gear meshing with the left sun gear, and the left planet carrier is connected to the left half shaft; it also includes a left inner gear ring, the inner teeth of the left inner gear ring mesh with the left planet gear, and the outer teeth mesh with the steering driven gear; The right planetary speed gear set includes a right sun gear arranged on the sun gear shaft, and a right planetary carrier, the right planetary carrier is provided with a right planetary gear meshing with the right sun gear, and the right planetary carrier is connected to the right half shaft; it also includes a right inner gear ring, the inner teeth of the right inner gear ring are meshed with the right planetary gear, and the outer teeth are meshed with the steering transition gear.

[0012] Compared with the prior art, the present invention has the following advantages: 1. The hydraulic pump is installed on the driven shaft after the forward gear and reverse gear are switched. The rotation direction of the hydraulic pump matches the forward gear or reverse gear direction. When the tractor moves forward and backward, the steering control direction is consistent with the actual movement direction, which is more in line with the steering operation habits, thereby avoiding safety accidents.

[0013] 2. The hydraulic pump inputs power from the speed-changing driven shaft, and the input speed is constant, so that the hydraulic pump is always in the rated working condition and the hydraulic transmission efficiency is high.

[0014] 3. The steering speed flow is not affected by gear changes, and can realize forward and reverse rotation of the crawler tracks at low speed, that is, making sharp turns at low speed; and realize differential steering of the two crawlers in the same direction at high speed, that is, making large turns at high speed, ensuring the safety of the tractor in hilly and complex terrain conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the transmission principle of the present invention; In the figure: 1, gearbox assembly 2, clutch shaft 3, reverse gear driving gear 4, reverse gear transition gear 5, reverse gear transition shaft 6, reverse gear driven gear 7, speed change driven shaft 8, hydraulic pump power input driving gear 9, hydraulic pump power input transition shaft 10, hydraulic pump power input transition gear 11, hydraulic pump speed change assembly 12, hydraulic pump power input driven gear 13, hydraulic pump 14, hydraulic pump reversing handle 15, forward gear driving gear 16, forward gear driven gear 17, meshing sleeve 18, hydraulic motor 19 , small bevel gear shaft 20, small bevel gear 21, large bevel gear 22, sun gear shaft 23, left planetary carrier 24, left half shaft 25, left planetary gear 26, left inner ring gear 27, steering driving gear 28, steering driven gear 29, steering transition gear 30, steering transition shaft 31, right inner ring gear 32, right planetary gear 33, right planetary carrier 34, right half shaft 35, hydraulic oil pipe 36, first gear switching assembly 37, second gear switching assembly 38, travel speed change assembly 39, reversing gear set. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] Example: See Figure 1 A crawler tractor steering control transmission system includes a fuel engine, a clutch, a gearbox assembly 1, a travel speed change assembly 38 and a steering control assembly. The fuel engine inputs power to the gearbox assembly 1 through the clutch shaft 2. The gearbox assembly 1 includes a first gear shift assembly 36 and a second gear shift assembly 37. The first gear shift assembly 36 is connected to the clutch shaft 2 in a driving manner, wherein the first gear shift assembly 36 is used for switching between a forward gear and a reverse gear, and the second gear shift assembly 37 is used for switching between different speed gears.

[0020] The first gear switching assembly 36 is connected to the travel speed change assembly 38 through the steering control assembly. The steering control assembly can input the first power to the travel speed change assembly 38 under the drive of the first gear switching assembly 36. The first power includes the forward steering power and the reverse steering power corresponding to the gear of the first gear switching assembly 36. The second gear switching assembly 37 is connected to the travel speed change assembly 38 to input the second power to the travel speed change assembly 38. The left and right travel half shafts of the travel speed change assembly 38 produce a speed difference under the superposition of the first power and the second power, driving the tracks on both sides to achieve steering.

[0021] Specifically, the present invention divides the power input by the fuel engine through the clutch shaft 2 into two parts, one part of the power is input to the walking speed change assembly 38 through the fuel engine-clutch shaft 2-first gear switching assembly 36-second gear switching assembly 37-walking speed change assembly 38 as walking power, i.e., the second power; the other part of the power is input to the walking speed change assembly 38 as steering power, i.e., the first power, through the fuel engine-clutch shaft 2-first gear switching assembly 36-steering control assembly-walking speed change assembly 38. After the first power and the second power converge in the walking speed change assembly 38, the left and right walking half shafts of the walking speed change assembly 38 produce a speed difference under the superposition of the first power and the second power, thereby driving the tracks on both sides to achieve steering.

[0022] Specifically, the first gear shift assembly 36 includes a speed-shift driven shaft 7, on which a reverse gear driven gear 6, a forward gear driven gear 16 and a hydraulic pump power input driving gear 8 are provided. An engaging seat for shifting operation and an engaging sleeve 17 that slidably cooperates with and meshes with the engaging seat are provided between the reverse gear driven gear 6 and the forward gear driven gear 16. When the forward gear is selected, the engaging sleeve 17 is meshed with the forward gear driven gear 16. Since the forward gear driven gear 16 is meshed with the forward gear driving gear 15 arranged on the clutch shaft 2, the speed-shift driven shaft 7 rotates under the transmission action of the engaging seat and the engaging sleeve 17, and is configured to rotate in the forward direction in this embodiment. When the reverse gear is selected, the engagement sleeve 17 is meshed with the reverse driven gear 6. Since the reverse driven gear 6 is meshed with the reverse driving gear 3 arranged on the clutch shaft 2 through a reverse transition gear 4 arranged on the reverse transition shaft 5, the speed change driven shaft 7 is rotated in the opposite direction under the transmission action of the engagement seat and the engagement sleeve 17, so that the rotation direction of the hydraulic pump power input driving gear 8 corresponds to the gear position of the first gear shift assembly 36 through the hydraulic pump power input driving gear 8, and the hydraulic pump power input driving gear 8 is transmission-connected to the steering control assembly.

[0023] Among them, the steering control assembly includes a hydraulic pump 13 and a hydraulic motor 18 connected thereto. The hydraulic pump 13 is installed on a hydraulic pump speed change assembly 11 and is transmission-connected to the hydraulic pump power input driving gear 8. The hydraulic motor 18 is connected to the travel speed change assembly 38 through a steering gear set and inputs steering power with opposite rotation directions to the left and right travel half-axles of the travel speed change assembly 38.

[0024] Specifically, the hydraulic pump speed change assembly 11 is provided with a hydraulic pump power input transition shaft 9, and a hydraulic pump power input transition gear 10 meshing with the hydraulic pump power input driving gear 8 is provided on the hydraulic pump power input transition shaft 9, and the hydraulic pump power input transition gear 10 meshes with the hydraulic pump power input driven gear 12 arranged on the input shaft of the hydraulic pump 13. The hydraulic pump 13 is provided with a reversing handle, and by turning the reversing handle, the hydraulic pump 13 can drive the hydraulic motor 18 to switch between forward rotation, stop rotation and reverse rotation.

[0025] Thus, in the forward gear: the meshing sleeve 17 meshes with the forward gear driven gear 16, and the power passes through: the clutch shaft 2 → the forward gear driving gear 15 → the forward gear driven gear 16 → the meshing sleeve 17 → the speed change driven shaft 7 → the hydraulic pump power input driving gear 8 → the hydraulic pump power input transition gear 10 → the hydraulic pump power input driven gear 12 → the hydraulic pump 13, and the hydraulic pump 13 rotates forward. When the hydraulic pump reversing handle 14 is in the left turn position, the hydraulic pump 13 outputs the forward hydraulic power through the hydraulic oil pipe 35, driving the hydraulic motor 18 to rotate forward; when the hydraulic pump reversing handle 14 is in the right turn position, the hydraulic pump 13 outputs the reverse hydraulic power, driving the hydraulic motor 18 to rotate reversely, so that the steering power matches the forward direction.

[0026] In reverse gear: the meshing sleeve 17 meshes with the reverse gear driven gear 6, and the power passes through: clutch shaft 2 → reverse gear driving gear 3 → reverse gear transition gear 4 → reverse gear driven gear 6 → meshing sleeve 17 → speed change driven shaft 7 → hydraulic pump power input driving gear 8 → hydraulic pump power input transition gear 10 → hydraulic pump power input driven gear 12 → hydraulic pump 13, and the hydraulic pump 13 rotates in the reverse direction. When the hydraulic pump reversing handle 14 is in the left turn position, the hydraulic pump 13 outputs reverse hydraulic power through the hydraulic oil pipe 35, driving the hydraulic motor 18 to rotate in the reverse direction; when the hydraulic pump reversing handle 14 is in the right turn position, the hydraulic pump 13 outputs forward hydraulic power, driving the hydraulic motor 18 to rotate forward, so that the steering power matches the reverse direction.

[0027] When the hydraulic pump reversing handle 14 is in the middle position, the hydraulic pump 13 has no hydraulic power output, the hydraulic motor 18 is in a hydraulic locking state, and no steering power output.

[0028] The reversing gear set 39 includes a steering driving gear 27 arranged on the output shaft of the hydraulic motor 18, and a steering driven gear 28 meshing with the steering driving gear 27. The steering driven gear 28 is connected to the left side of the travel half-axle of the travel speed change assembly 38 through a driving connection, and is connected to the right side of the travel half-axle of the travel speed change assembly 38 through a steering transition gear 29 arranged on a steering transition shaft 30, so that the hydraulic motor 18 inputs steering power with opposite rotation directions to the left and right travel half-axles of the travel speed change assembly 38.

[0029] Specifically, the travel speed change assembly 38 includes a sun gear shaft 22, on which a large bevel gear 21 is provided, and the large bevel gear 21 is meshed with a small bevel gear 20 arranged on a small bevel gear shaft 19, and the small bevel gear shaft 19 is transmission connected to the second gear switching assembly 37; the two ends of the sun gear shaft 22 are respectively connected to the left planetary speed change gear set and the right planetary speed change gear set, and are respectively used to drive the left and right travel half-axes corresponding to the left and right tracks, namely the left half-axle 24 and the right half-axle 34, wherein the left planetary speed change gear set is transmission connected to the steering driven gear 28, and the right planetary speed change gear set is transmission connected to the steering transition gear 29.

[0030] The left planetary gear set includes a left sun gear arranged on a sun gear shaft 22, and a left planet carrier 23, the left planet carrier 23 is provided with a left planet gear 25 meshing with the left sun gear, and the left planet carrier 23 is connected to the left half shaft 24; and also includes a left inner gear ring 26, the inner teeth of the left inner gear ring 26 meshing with the left planet gear 25, and the outer teeth meshing with the steering driven gear 28; The right planetary speed gear set includes a right sun gear arranged on the sun gear shaft 22, and a right planetary carrier 33, on which a right planetary gear 32 meshing with the right sun gear is provided, and the right planetary carrier 33 is connected to the right half shaft 34; it also includes a right inner gear ring 31, the inner teeth of the right inner gear ring 31 mesh with the right planetary gear 32, and the outer teeth mesh with the steering transition gear 29.

[0031] In this way, when the second gear shift assembly 37 outputs a low speed, the speed of the sun gear shaft 22 is low, that is, the left sun gear and the right sun gear are low speed, and the hydraulic motor 18 inputs a certain speed to the right inner gear ring 31 through the steering transition gear 29, and at the same time, the hydraulic motor 18 inputs a certain speed to the left inner gear ring 26 through the steering driven gear 28, and the speeds of the two are opposite, so that the speeds of the left inner gear ring 26 and the left sun gear are superimposed, and the speeds of the right inner gear ring 31 and the right sun gear are superimposed, so that the left half shaft 24 and the right half shaft 34 generate rotation. Speed ​​difference, or opposite speed is produced. In actual application, the fuel engine outputs at the rated speed, the speed of the hydraulic motor 18 is relatively stable, and the final speeds of the left half shaft 24 and the right half shaft 34 are controlled by the output of the second gear switching assembly 37. When the low speed gear is in the gear position, the left half shaft 24 and the right half shaft 34 rotate forward and reverse to achieve a U-turn on the spot (sharp turn), and when the high speed gear is in the gear position, the left half shaft 24 and the right half shaft 34 rotate in the same direction at a differential speed, thereby achieving a large radius turn (large turn), which can effectively prevent overturning and ensure the safety of operations in hilly areas.

[0032] In summary, the present invention: 1. The hydraulic pump is installed on the driven shaft after the forward gear and reverse gear are switched. The rotation direction of the hydraulic pump matches the forward gear or reverse gear direction. When the tractor moves forward and backward, the steering control direction is consistent with the actual movement direction, which is more in line with the steering operation habits, thereby avoiding safety accidents.

[0033] 2. The hydraulic pump inputs power from the speed-changing driven shaft, and the input speed is constant, so that the hydraulic pump is always in the rated working condition and the hydraulic transmission efficiency is high.

[0034] 3. The steering speed flow is not affected by gear changes, and can realize forward and reverse rotation of the crawler tracks at low speed, that is, making sharp turns at low speed; and realize differential steering of the two crawlers in the same direction at high speed, that is, making large turns at high speed, ensuring the safety of the tractor in hilly and complex terrain conditions.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A crawler tractor steering control transmission system, characterized in that: It includes a fuel engine, a gearbox assembly, a travel speed change assembly and a steering control assembly. The fuel engine inputs power to the gearbox assembly through a clutch shaft. The gearbox assembly includes a first gear shift assembly and a second gear shift assembly. The first gear shift assembly is in driving connection with the clutch shaft, wherein the first gear shift assembly is used for switching between forward gear and reverse gear, and the second gear shift assembly is used for switching between different speed gears. The first gear switching assembly is connected to the travel speed change assembly through the steering control assembly. The steering control assembly can input a first power to the travel speed change assembly under the drive of the first gear switching assembly. The first power includes a forward steering power and a reverse steering power corresponding to the gear of the first gear switching assembly. The second gear switching assembly is connected to the travel speed change assembly to input a second power to the travel speed change assembly. The left and right travel half shafts of the travel speed change assembly generate a speed difference under the superposition of the first power and the second power, and drive the tracks on both sides to achieve steering.

2. A crawler tractor steering control transmission system according to claim 1, characterized in that: The first gear shift assembly includes a speed change driven shaft, on which a reverse gear driven gear, a forward gear driven gear and a hydraulic pump power input driving gear are provided. When the forward gear is selected, the forward gear driven gear meshes with the forward gear driving gear arranged on the clutch shaft. When the reverse gear is selected, the reverse gear driven gear meshes with the reverse gear driving gear arranged on the clutch shaft through a reverse gear transition gear arranged on the reverse gear transition shaft, so that the rotation direction of the hydraulic pump power input driving gear corresponds to the gear position of the first gear shift assembly, and the hydraulic pump power input driving gear is transmission-connected to the steering control assembly.

3. A crawler tractor steering control transmission system according to claim 2, characterized in that: The steering control assembly includes a hydraulic pump and a hydraulic motor connected thereto. The hydraulic pump is installed on a hydraulic pump speed change assembly and is transmission-connected to a hydraulic pump power input driving gear. The hydraulic motor is connected to a travel speed change assembly through a steering gear set and inputs steering power with opposite rotation directions to the left and right travel half-axles of the travel speed change assembly.

4. A crawler tractor steering control transmission system according to claim 3, characterized in that: The hydraulic pump speed change assembly is provided with a hydraulic pump power input transition shaft, and the hydraulic pump power input transition shaft is provided with a hydraulic pump power input transition gear meshing with the hydraulic pump power input driving gear, and the hydraulic pump power input transition gear is meshed with the hydraulic pump power input driven gear arranged on the input shaft of the hydraulic pump.

5. A crawler tractor steering control transmission system according to claim 3, characterized in that: The hydraulic pump is provided with a reversing handle, and by turning the reversing handle, the hydraulic pump can drive the hydraulic motor to switch between forward rotation, stop rotation and reverse rotation.

6. A crawler tractor steering control transmission system according to claim 3, characterized in that: The reversing gear set includes a steering driving gear arranged on the output shaft of the hydraulic motor, and a steering driven gear meshing with the steering driving gear. The steering driven gear is drivingly connected to the left side traveling half-axle of the traveling speed change assembly, and is drivingly connected to the right side traveling half-axle of the traveling speed change assembly through the steering transition gear arranged on the steering transition shaft, so that the hydraulic motor inputs steering power with opposite rotation directions to the left and right traveling half-axles of the traveling speed change assembly.

7. A crawler tractor steering control transmission system according to claim 6, characterized in that: The travel speed change assembly includes a sun gear shaft, on which a large bevel gear is provided, the large bevel gear is meshed with a small bevel gear, and the small bevel gear is transmission connected to the second gear switching assembly; the two ends of the sun gear shaft are respectively connected to the left planetary speed change gear set and the right planetary speed change gear set, which are respectively used to drive the left half shaft and the right half shaft connected to the left and right crawlers respectively, wherein the left planetary speed change gear set is transmission connected to the steering driven gear, and the right planetary speed change gear set is transmission connected to the steering transition gear.

8. A crawler tractor steering control transmission system according to claim 7, characterized in that: The left planetary speed change gear set includes a left sun gear arranged on the sun gear shaft, and a left planet carrier, the left planet carrier is provided with a left planet gear meshing with the left sun gear, and the left planet carrier is connected to the left half shaft; and also includes a left inner gear ring, the inner teeth of the left inner gear ring mesh with the left planet gear, and the outer teeth mesh with the steering driven gear; The right planetary speed gear set includes a right sun gear arranged on the sun gear shaft, and a right planetary carrier, the right planetary carrier is provided with a right planetary gear meshing with the right sun gear, and the right planetary carrier is connected to the right half shaft; it also includes a right inner gear ring, the inner teeth of the right inner gear ring are meshed with the right planetary gear, and the outer teeth are meshed with the steering transition gear.

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