Simple tractor stepless speed change transmission system

Abstract

A simple tractor stepless speed change transmission system belongs to the technical field of tractor speed change and comprises an engine, a stepless transmission assembly and a rear axle assembly. The continuously variable transmission assembly comprises a box body, a gear shifting mechanism and a planetary gear train, and an electric proportional variable pump is arranged on the box body. A pump driven gear is arranged at the input end of the electric proportional variable pump, and a planetary gear train input driving gear is arranged at the output end of the electric proportional variable pump. A planetary gear train input driven gear is arranged at the input end of the planetary gear train, an input driving gear is arranged at the output end of the planetary gear train, and the planetary gear train is in transmission connection with the rear axle assembly through the input driving gear. The simple tractor stepless speed change transmission system is reasonable in design, stepless speed change is achieved through hydraulic and mechanical confluence, a single planetary gear train is adopted, the structure is simple, manufacturing cost can be effectively reduced, maintenance is convenient, economic benefits are good, and the simple tractor stepless speed change transmission system is suitable for popularization.

Description

Technical Field

[0001] The utility model relates to the technical field of tractor transmission, in particular to a simple stepless speed change transmission system for tractors. Background Art

[0002] A tractor is a piece of heavy machinery used in agriculture, forestry, and engineering. It is primarily designed to tow, push, or transport various equipment and tools, as well as perform various agricultural operations such as tilling, sowing, and harvesting. A tractor typically consists of an engine, transmission, travel system, steering system, working attachments, and a cab. The engine is the tractor's power source, the transmission system transmits the engine's power to the travel system and working attachments, the travel system enables the tractor to move and perform various operations, the steering system controls the tractor's direction of travel, and the working attachments perform various agricultural operations as needed. The cab provides a comfortable operating environment for the driver.

[0003] Currently, with the continuous development of tractor transmission systems, continuously variable transmission (CVT) technology has been gradually adopted, following the evolution of technologies such as slip gear shifting, clutch sleeve shifting, synchronizer shifting, and power shifting. Continuously variable transmission (CVT) is an advanced transmission technology that allows tractors to smoothly and continuously adjust their speed during operation, eliminating the need for gear shifting required by traditional transmissions. Continuously variable transmissions typically achieve continuous speed changes by varying the transmission ratio. This can be achieved through a variety of methods, including but not limited to hydraulic transmissions, electric transmissions, and mechanical CVTs (such as V-belts and chains).

[0004] Although the existing continuously variable transmission technology for tractors has many advantages, it still has the following shortcomings in actual use: the continuously variable transmission system uses a dual-section planetary gear system, and the shifting method uses a wet clutch, which has high manufacturing costs and is inconvenient to maintain, affecting economic benefits. Utility Model Content

[0005] In view of the shortcomings of the current tractor continuously variable transmission system, such as high manufacturing cost and inconvenient maintenance, the utility model provides a simple tractor continuously variable transmission system, which has a reasonable design, realizes continuously variable speed through hydraulic and mechanical convergence, and adopts a single planetary gear system with a simple structure. It can not only effectively reduce manufacturing costs, but also facilitate maintenance, has good economic benefits, and is suitable for promotion.

[0006] In order to solve the above technical problems, the technical solution adopted by the utility model is as follows: a simple tractor continuously variable transmission system includes an engine, a continuously variable transmission assembly and a rear axle assembly, the engine is connected to an input shaft, and the continuously variable transmission assembly and the rear axle assembly are connected to the input shaft; the continuously variable transmission assembly includes a box body, a shift mechanism and a planetary gear train, the shift mechanism and the planetary gear train are assembled inside the box body, and an electric proportional variable pump is arranged on the box body; the input end of the electric proportional variable pump is provided with a pump driven gear, and the side of the shift mechanism close to the engine is provided with a pump driving gear assembled on the input shaft, and the pump driving gear is connected to the pump driven gear; the output end of the electric proportional variable pump is provided with a planetary gear train output gear. The input driving gear is provided at the input end of the planetary gear train, and the planetary gear train input driven gear is transmission-connected to the planetary gear train input driven gear; the output end of the planetary gear train is provided with an input driving gear, and the planetary gear train is transmission-connected to the rear axle assembly through the input driving gear; the rear axle assembly includes a housing, a four-section shifting mechanism and a PTO mechanism, the four-section shifting mechanism and the PTO mechanism are assembled inside the housing, and the PTO mechanism is rotationally connected to the input shaft; the input end of the four-section shifting mechanism is provided with an input driven gear, and the input driving gear is transmission-connected to the input driven gear; the output end of the four-section shifting mechanism is transmission-connected to the terminal reduction mechanism and the four-wheel drive mechanism assembled inside the housing.

[0007] Preferably, a torsional vibration damper is provided at the connection between the engine and the input shaft.

[0008] Preferably, a planetary gear train input intermediate gear shaft is provided between the planetary gear train input driving gear and the planetary gear train input driven gear, an intermediate gear is assembled on the planetary gear train input intermediate gear shaft, and the planetary gear train input driving gear and the planetary gear train input driven gear are connected through the intermediate gear.

[0009] Preferably, the four-section shift mechanism is equipped with a shift valve block.

[0010] Preferably, the four-wheel drive mechanism is equipped with a shift valve block.

[0011] Preferably, the PTO mechanism is equipped with a shift valve block.

[0012] It can be seen from the above technical solutions that the advantages of the present invention are: the transmission system adopts a front convergence of the gearbox, and realizes hydraulic + mechanical convergence through the design of an electric proportional variable pump, thereby realizing stepless speed change; at the same time, the transmission system only adopts one planetary gear system, that is, a single planetary gear mechanism, which has a simple structure and reduces manufacturing cost; and the transmission system realizes electric shifting through the design of the shift valve block, which is comfortable to operate and effectively improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for the description. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0014] Figure 1 It is a structural schematic diagram of a specific embodiment of the utility model.

[0015] 1. Torsional vibration damper; 2. Pump driven gear; 3. Reverse gear driving gear; 4. Electric proportional variable pump; 5. Reversing clutch; 6. Forward gear driving gear; 7. Planetary gear input driving gear; 8. Planetary gear input intermediate gear shaft; 9. Input driven gear; 10. A gear driving gear; 11. B gear driving gear; 12. C gear driving gear; 13. D gear driving gear; 14. Pump driving gear; 15. Reverse idler gear; 16. Reverse driven gear; 17. Forward driven gear; 1 8. Planetary gear train input driven gear; 19. Planetary gear train; 20. Input driving gear; 21. A gear driven gear; 22. B gear driven gear; 23. C gear driven gear; 24. D gear driven gear; 25. Small bevel gear; 26. Large bevel gear; 27. Shift valve block; 28. Four-wheel drive mechanism; 29. ​​PTO clutch; 30. PTO low-speed driving gear; 31. PTO high-speed driving gear; 32. PTO low-speed driven gear; 33. PTO high-speed driven gear. DETAILED DESCRIPTION

[0016] In order to make the purpose, features, and advantages of the present invention more obvious and easy to understand, the technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the specific embodiments. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this patent.

[0017] Please refer to the attached Figure 1 The present invention describes a simplified continuously variable transmission system for tractors, comprising an engine, a continuously variable transmission assembly, and a rear axle assembly. Incorporating existing tractor transmission systems, the engine is connected to an input shaft, while the continuously variable transmission assembly and the rear axle assembly are connected to the input shaft. Specifically, a torsional vibration damper (1) is provided at the connection between the engine and the input shaft.

[0018] The continuously variable transmission assembly includes a housing, a shift mechanism, and a planetary gear train 19. Specifically, the shift mechanism includes a reverse drive gear 3, a reversing clutch 5, a forward drive gear 6, a reverse idler gear 15, a reverse driven gear 16, and a forward driven gear 17. The shift mechanism switches between forward and reverse gears via the reversing clutch 5, transmitting power to the forward drive gear 6 or the reverse drive gear 3, enabling forward or reverse travel. The detailed structures of the shift mechanism and the planetary gear train 19 can be found in existing transmission technology and will not be further elaborated in this specification.

[0019] The shift mechanism and planetary gear train 19 are assembled inside the housing, and the housing is provided with an electric proportional variable pump 4. The input end of the electric proportional variable pump 4 is provided with a pump driven gear 2, and the side of the shift mechanism close to the engine is provided with a pump driving gear 14 assembled on the input shaft, and the pump driving gear 14 is transmission-connected to the pump driven gear 2. The output end of the electric proportional variable pump 4 is provided with a planetary gear train input driving gear 7, and the input end of the planetary gear train 19 is provided with a planetary gear train input driven gear 18, and the planetary gear train input driving gear 7 is transmission-connected to the planetary gear train input driven gear 18. The output end of the planetary gear train 19 is provided with an input driving gear 20, and the planetary gear train 19 is transmission-connected to the rear axle assembly via the input driving gear 20.

[0020] This transmission system adopts a front convergence of the gearbox and realizes hydraulic + mechanical convergence through the design of the electric proportional variable pump 4, thereby realizing stepless speed change; at the same time, this transmission system only adopts one planetary gear system 19, that is, a single planetary gear mechanism, which has a simple structure and reduces manufacturing costs.

[0021] The rear axle assembly includes a housing, a four-section shift mechanism, and a PTO mechanism. The four-section shift mechanism and the PTO mechanism are assembled inside the housing, and the PTO mechanism is rotationally connected to the input shaft. Specifically, the four-section shift mechanism includes an A-gear driving gear 10, a B-gear driving gear 11, a C-gear driving gear 12, a D-gear driving gear 13, an A-gear driven gear 21, a B-gear driven gear 22, a C-gear driven gear 23, and a D-gear driven gear 24. The four-section shift mechanism has four shift sections: A-gear, B-gear, C-gear, and D-gear. Specifically, the PTO mechanism includes a PTO clutch 29, a PTO low-speed driving gear 30, a PTO high-speed driving gear 31, a PTO low-speed driven gear 32, and a PTO high-speed driven gear 33. The PTO mechanism is used to transmit and connect agricultural machinery. The detailed structure of the four-section shift mechanism and the detailed structure of the PTO mechanism can be referred to existing transmission technology and will not be described in detail in this specification.

[0022] The input end of the four-range shift mechanism is equipped with an input driven gear 9, to which an input driving gear 20 is drivingly connected. The output end of the four-range shift mechanism is drivingly connected to a final reduction mechanism and a four-wheel drive mechanism 28 assembled within the housing. Specifically, the final reduction mechanism includes a small bevel gear 25 and a large bevel gear 26, and is used for driving connection to the wheels. The detailed structures of the final reduction mechanism and the four-wheel drive mechanism 28 can be referenced in existing transmission technology and will not be further elaborated in this specification.

[0023] The operating principle of this utility model is as follows: This transmission system is equipped with a torsional vibration damper 1 at the connection between the input shaft and the engine. The electric proportional variable pump 4 is driven by the cooperation of the pump driving gear 14 and the pump driven gear 2. The electric proportional variable pump 4 drives the planetary gear input driving gear 7, which in turn drives the planetary gear 19 through the cooperation of the planetary gear input driving gear 7 and the planetary gear input driven gear 18. The planetary gear 19 drives the input driving gear 20, which in turn drives the input driven gear 9, so that the hydraulic flow is merged into the transmission. Then, through the confluence of the mechanical flow, the power flow is transmitted to the various gears of the transmission, and ultimately drives the terminal.

[0024] In one embodiment, a planetary gear input intermediate gear shaft 8 is disposed between the planetary gear input driving gear 7 and the planetary gear input driven gear 18. An intermediate gear is mounted on the planetary gear input intermediate gear shaft 8, and the planetary gear input driving gear 7 and the planetary gear input driven gear 18 are connected via the intermediate gear. This structural design is more rational and can ensure power transmission between the planetary gear input driving gear 7 and the planetary gear input driven gear 18.

[0025] In one embodiment, a four-range shift mechanism is equipped with a shift valve block 27. The four-range shift mechanism comprises A, B, C, and D gears, and its shift unit is equipped with a shift valve block 27, enabling electronic gear selection. When the vehicle speed reaches a certain speed range, a signal is sent to the range transmission to shift gears.

[0026] In one embodiment, the four-wheel drive mechanism 28 is equipped with a shift valve block 27. The four-wheel drive mechanism 28 performs the engagement and disengagement of the four-wheel drive shift through the shift valve block 27.

[0027] In one embodiment, the PTO mechanism is equipped with a shift valve block 27. The PTO mechanism is equipped with high and low speed PTOs, and uses the shift valve block 27 for shifting. The PTO clutch 29 is used to connect and disconnect power. The reversing group and the speed change group are used to control travel, and the power take-off group is used for machine operation.

[0028] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0029] The terms "upper," "lower," "outer," "inner," and the like, if used in the specification and claims of the present invention and the accompanying drawings, are used to distinguish relative positions and do not necessarily define them. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0030] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A simple tractor continuously variable transmission system, comprising an engine, a continuously variable transmission assembly and a rear axle assembly, wherein the engine is connected to an input shaft, and the continuously variable transmission assembly and the rear axle assembly are connected to the input shaft, characterized in that: The continuously variable transmission assembly includes a housing, a shift mechanism and a planetary gear train (19). The shift mechanism and the planetary gear train (19) are assembled inside the housing, and an electric proportional variable pump (4) is arranged on the housing; an input end of the electric proportional variable pump (4) is provided with a pump driven gear (2); a side of the shift mechanism close to the engine is provided with a pump driving gear (14) assembled on the input shaft, and the pump driving gear (14) is transmission-connected to the pump driven gear (2); an output end of the electric proportional variable pump (4) is provided with a planetary gear train input driving gear (7), an input end of the planetary gear train (19) is provided with a planetary gear train input driven gear (18), and the planetary gear train input driving gear (7) is transmission-connected to the planetary gear train input driven gear (19). The planetary gear system input driven gear (18) is connected in transmission; the output end of the planetary gear system (19) is provided with an input driving gear (20), and the planetary gear system (19) is connected in transmission to the rear axle assembly through the input driving gear (20); the rear axle assembly includes a housing, a four-section shift mechanism and a PTO mechanism, the four-section shift mechanism and the PTO mechanism are assembled inside the housing, and the PTO mechanism is connected in rotation to the input shaft; the input end of the four-section shift mechanism is provided with an input driven gear (9), and the input driving gear (20) is connected in transmission to the input driven gear (9); the output end of the four-section shift mechanism is connected in transmission to the terminal reduction mechanism and the four-wheel drive mechanism assembled inside the housing.

2. A simple tractor continuously variable transmission system according to claim 1, characterized in that: A torsional vibration damper (1) is provided at the connection between the engine and the input shaft.

3. A simple tractor continuously variable transmission system according to claim 2, characterized in that: A planetary gear train input intermediate gear shaft (8) is provided between the planetary gear train input driving gear (7) and the planetary gear train input driven gear (18), an intermediate gear is mounted on the planetary gear train input intermediate gear shaft (8), and the planetary gear train input driving gear (7) and the planetary gear train input driven gear (18) are connected in transmission via the intermediate gear.

4. A simple tractor continuously variable transmission system according to claim 3, characterized in that: The four-section shift mechanism is equipped with a shift valve block (27).

5. The simplified tractor continuously variable transmission system according to claim 4, characterized in that: The four-wheel drive mechanism is equipped with a shift valve block (27).

6. A simple tractor continuously variable transmission system according to claim 5, characterized in that: The PTO mechanism is equipped with a shift valve block (27).

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