Double-HST transmission case structure of crawler tractor

Abstract

The invention discloses a double-HST transmission case structure of a crawler tractor, which relates to the field of tractor transmission and comprises a transmission case shell, a power input part is arranged at the front end of the transmission case shell, a sun wheel shaft and a power output part are arranged at the tail end of the transmission case shell, and planetary gear train mechanisms are stacked and distributed on the left side and the right side of the sun wheel shaft. A walking transmission assembly and a steering assembly are arranged in the transmission box shell, and the walking transmission assembly is arranged in the transmission box shell and used for adjusting the rotating speed of the sun wheel shaft. Compared with a traditional crawler transmission system, the double-HST transmission case structure of the crawler tractor has the advantage of hydraulic and mechanical walking power switching, high efficiency of mechanical power and flexibility of hydraulic power are combined, the hydraulic planet differential steering technology is integrated, and compared with a traditional steering clutch gearbox, the double-HST transmission case structure of the crawler tractor has the advantages that no quick-wear part exists in the system, and the system is more stable and reliable. The system is long in service life.

Description

Technical Field

[0001] The invention relates to the technical field of tractor transmission, in particular to a double HST transmission box structure for a crawler tractor. Background Art

[0002] As a common agricultural production machinery, tractors can effectively improve agricultural work efficiency. As an important component of tractors, transmission boxes play the role of controlling the output power of tractors.

[0003] Prior art 1 (application number 202223564636.8, Chinese patent published on June 6, 2023) A tractor gearbox with HST, including an HST transmission mechanism, a main transmission mechanism, and a high-low gear mechanism connected in sequence, the high-low gear mechanism is arranged on the rear side of the main transmission mechanism, and the four speed gears in the main transmission mechanism are adjusted to output eight different speed gears; the HST is installed on the front side of the main transmission mechanism, and is connected to the power input shaft in the gearbox through the HST power output shaft to transmit the power of the engine to the power output mechanism; the output shaft is driven by the HST It is connected to the internal spline of the constantly meshing driving gear to transmit the driving force to the driving output mechanism. The gearbox structure provided by this scheme is simple. The HST transmission mechanism is combined with the above-mentioned two speed change mechanisms to complete the output of eight forward gears and eight reverse gears, thereby improving the operating capacity of the tractor; Prior art 2 (application number is 201910359581.0, a Chinese patent published on May 1, 2020) A tracked vehicle speed change transmission equipment, which includes a box assembly, a transmission assembly, a differential steering assembly, a main reducer assembly and a PTO speed change assembly. Among them, the transmission assembly, differential steering assembly, main reducer assembly, and PTO speed change assembly are installed on the box assembly. The transmission assembly has four high-speed gears and four low-speed gears. The differential steering assembly adopts HST to directly control the worm. The worm adjusts the worm wheels of the differential devices on both sides to realize vehicle steering. The main reducer assembly has the main reduction function and also has the function of switching forward and reverse. In conjunction with the transmission assembly, it realizes a forward 8-speed and reverse 8-speed combination. The invention adopts a combined shifting, with many gears and good matching performance with agricultural machinery. It adopts HST direct connection to control the steering of the crawler vehicle. It has the advantages of simple structure, high steering accuracy, and adjustable steering instantaneous rate.

[0004] The current transmission box directly uses mechanical transmission, which has high transmission efficiency but poor flexibility. The use of hydraulic transmission improves flexibility, but the transmission efficiency decreases. The system has a short service life due to the setting of wearing parts inside. Summary of the invention

[0005] The purpose of the present invention is to provide a double HST transmission box structure for a crawler tractor to solve the problem proposed in the above background technology that the current transmission box directly uses mechanical transmission, although it has a high transmission efficiency, it has poor flexibility. The use of hydraulic transmission improves flexibility, but the transmission efficiency will decrease, and the system has a low service life due to the setting of wearing parts inside.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a double HST transmission box structure for a crawler tractor, comprising a transmission box housing, a power input part is arranged at the front end of the transmission box housing, a sun gear shaft and a power output part are arranged at the rear end of the transmission box housing, a planetary gear train mechanism is arranged on the left and right sides of the sun gear shaft, a travel transmission assembly and a steering assembly are arranged inside the transmission box housing, the travel transmission assembly is arranged inside the transmission box housing, and is used to adjust the rotation speed of the sun gear shaft, an HST1 that cooperates with the travel transmission assembly is arranged on the side wall of the transmission box housing, the steering assembly is arranged inside the transmission box housing, and an HST2 that cooperates with the steering assembly is arranged on the outer wall of the transmission box housing.

[0007] To further optimize the technical solution, both HST1 and HST2 are split-type structural designs.

[0008] To further optimize the technical solution, both HST1 and HST2 include a variable pump and a hydraulic motor, and the variable pump and the hydraulic motor are connected to each other.

[0009] To further optimize the technical solution, the power input unit is a diesel engine, which provides power input for the transmission system.

[0010] To further optimize the technical solution, an input shaft is provided at the rear side of the power input part, and a clutch is provided at the front end of the input shaft, and the power input part is connected to the input shaft via the clutch.

[0011] To further optimize the technical solution, a first transmission gear is disposed on the outer side of the input shaft, and the input shaft transmits power to HST1 and HST2 through the first transmission gear.

[0012] To further optimize the technical solution, a mechanical gear, a power gear and an HST gear are provided on the rear side of the first transmission gear.

[0013] To further optimize the technical solution, the hydraulic motor in the HTS1 is connected to the HST output shaft, and the HST output shaft is connected to a small spiral bevel gear pair, and the small spiral bevel gear pair is connected to the input shaft.

[0014] To further optimize the technical solution, a high gear and a low gear are sequentially arranged on the rear side of the small spiral bevel gear pair.

[0015] To further optimize the technical solution, a second transmission gear is provided on the outer side of the sun gear shaft.

[0016] Compared with the prior art, the beneficial effect of the present invention is that compared with the traditional crawler transmission system, the invention has the advantage of switching between hydraulic and mechanical walking power, combining the high efficiency of mechanical power with the flexibility of hydraulic power, and integrating hydraulic planetary differential steering technology. Compared with the traditional steering clutch gearbox, it has the advantages of no wearing parts in the system, long system service life, and high steering accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the transmission structure principle of the present invention.

[0018] In the figure: 1. power input part; 2. input shaft; 3. clutch; 4. first transmission gear; 5. variable pump; 6. hydraulic motor; 7. mechanical gear; 8. power gear; 9. HST gear; 10. HST output shaft; 11. small spiral bevel gear pair; 12. high gear; 13. low gear; 14. second transmission gear; 15. sun gear shaft; 16. planetary gear mechanism. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0020] See also Figure 1 , the present invention provides the following technical solutions: a double HST transmission case structure for a crawler tractor, comprising a transmission case housing; Embodiment 1: The invention provides a technical solution, which discloses that a power input part 1 is provided at the front end of the transmission box housing, a sun gear shaft 15 and a power output part are provided at the rear end of the transmission box housing, a planetary gear train mechanism 16 is arranged on the left and right sides of the sun gear shaft 15, a travel transmission assembly and a steering assembly are provided inside the transmission box housing, the travel transmission assembly is provided inside the transmission box housing, and is used to adjust the rotation speed of the sun gear shaft 15, an HST1 that cooperates with the travel transmission assembly is provided on the side wall of the transmission box housing, the steering assembly is provided inside the transmission box housing, and an HST2 that cooperates with the steering assembly is provided on the outer wall of the transmission box housing.

[0021] This structure has the advantages of switching between hydraulic and mechanical travel power, combining the high efficiency of mechanical power with the flexibility of hydraulic power, integrating hydraulic planetary differential steering technology, and achieving no wearing parts in the system compared to traditional steering clutch gearboxes.

[0022] Embodiment 2: On the basis of embodiment 1, it is disclosed that HST1 and HST2 are both of split structure design, HST1 and HST2 both include variable pump 5 and hydraulic motor 6, variable pump 5 and hydraulic motor 6 are connected to each other, power input part 1 is a diesel engine, providing power input for the transmission system, input shaft 2 is arranged at the rear side of power input part 1, and clutch 3 is arranged at the front end of input shaft 2, power input part 1 is connected with input shaft 2 through clutch 3, first transmission gear 4 is arranged at the outer side of input shaft 2, input shaft 2 transmits power to HST1 and HST2 through first transmission gear 4, mechanical gear 7, power gear 8 and HST gear 9 are arranged at the rear side of first transmission gear 4, hydraulic motor 6 in HTS1 is connected with HST output shaft 10, and small spiral bevel gear pair 11 is connected to HST output shaft 10, small spiral bevel gear pair 11 is connected with input shaft 2, high gear 12 and low gear 13 are arranged in sequence at the rear side of small spiral bevel gear pair 11, and second transmission gear 14 is arranged at the outer side of sun gear shaft 15.

[0023] The power input part 1 composed of a diesel engine transmits power to the input shaft 2, driving the first transmission gear 4. The first transmission gear 4 drives two variable pumps 5 on the left and right of the transmission case housing. When the power gear 8 is connected to the mechanical gear 7, the power is directly transmitted, and high and low gear shifting can be realized to achieve power transmission. When the power gear 8 is connected to the HST gear 9, the variable pump 5 of HST1 supplies oil to the connected hydraulic motor 6, and the hydraulic motor 6 drives the small spiral bevel gear pair 11 to transmit power to drive the gear, and the HST stepless speed change is achieved by changing the oil amount of the variable pump 5; the first transmission gear 4 drives another HST2, and the variable pump 5 supplies oil to the connected hydraulic motor 6, and the hydraulic motor 6 drives the gear pair of the steering part to achieve differential steering. The second transmission gear 14 can realize forward and reverse operations.

[0024] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

[0025] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A double HST transmission case structure for a crawler tractor, comprising a transmission case housing; Features: The front end of the transmission case housing is provided with a power input portion (1), the rear end of the transmission case housing is provided with a sun gear shaft (15) and a power output portion, the left and right sides of the sun gear shaft (15) are provided with planetary gear train mechanisms (16), a travel transmission assembly and a steering assembly are provided inside the transmission case housing, the travel transmission assembly is provided inside the transmission case housing and is used to adjust the rotation speed of the sun gear shaft (15), an HST1 cooperating with the travel transmission assembly is provided on the side wall of the transmission case housing, the steering assembly is provided inside the transmission case housing, and an HST2 cooperating with the steering assembly is provided on the outer wall of the transmission case housing; The HST1 and HST2 are both of split-type structural design; the power input part (1) is a diesel engine, which provides power input for the transmission system.

2. A crawler tractor double HST transmission box structure according to claim 1, characterized in that: The HST1 and HST2 both include a variable displacement pump (5) and a hydraulic motor (6), and the variable displacement pump (5) and the hydraulic motor (6) are connected to each other.

3. A crawler tractor double HST transmission box structure according to claim 2, characterized in that: An input shaft (2) is arranged at the rear side of the power input part (1), and a clutch (3) is arranged at the front end of the input shaft (2); the power input part (1) is connected to the input shaft (2) via the clutch (3).

4. A crawler tractor double HST transmission box structure according to claim 3, characterized in that: A first transmission gear (4) is arranged on the outer side of the input shaft (2), and the input shaft (2) transmits power to HST1 and HST2 via the first transmission gear (4).

5. A crawler tractor double HST transmission box structure according to claim 4, characterized in that: A mechanical gear (7), a power gear (8) and an HST gear (9) are arranged on the rear side of the first transmission gear (4).

6. A crawler tractor double HST transmission box structure according to claim 5, characterized in that: The hydraulic motor (6) in the HTS1 is connected to an HST output shaft (10), and the HST output shaft (10) is connected to a small spiral bevel gear pair (11), and the small spiral bevel gear pair (11) is connected to the input shaft (2).

7. A crawler tractor double HST transmission box structure according to claim 6, characterized in that: A high gear (12) and a low gear (13) are sequentially arranged on the rear side of the small spiral bevel gear pair (11).

8. A crawler tractor double HST transmission box structure according to claim 7, characterized in that: A second transmission gear (14) is arranged on the outer side of the sun gear shaft (15).

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