Vehicle transmission system capable of realizing partial stepless speed change

Abstract

The invention relates to the technical field of agricultural machinery, and discloses a vehicle transmission system capable of realizing partial stepless speed change, which comprises a main transmission shaft and an auxiliary transmission, an auxiliary driven shaft is arranged at the input end of the auxiliary transmission, and a hydraulic transmission wheel and a mechanical transmission wheel are sleeved on the main transmission shaft; the auxiliary driven shaft is fixedly connected with a change wheel and a driven wheel in power transmission with the mechanical transmission wheel, and further comprises a power combination device for controlling the power transmission between the hydraulic transmission wheel and the main transmission shaft or the power transmission between the mechanical transmission wheel and the main transmission shaft; the variable pump is in power transmission with the hydraulic transmission wheel, the hydraulic motor is connected with the variable pump through a hydraulic pipeline, the hydraulic motor is in power connection with the change wheel, and a power output shaft used for transmitting power to a vehicle wheel set is arranged at the output end of the auxiliary transmission. The stepless speed change transmission is convenient to operate and simple and compact in space structure, and stepless speed change can be achieved only by changing a small structure on the basis that a transmission structure and the size of an existing transmission are not changed.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural machinery, and in particular to a vehicle transmission system for realizing partial stepless speed change. Background Art

[0002] In the traditional mechanical transmission system, the tractor's gearbox can usually achieve a transmission efficiency of 95%-97% due to its efficient energy transmission characteristics. However, this mechanical transmission method has a significant limitation, that is, it can only achieve stepped speed change, but not stepless speed change. This means that the driver needs to switch gears frequently during operation to adapt to different working conditions and load requirements, which not only increases the complexity of operation, but may also lead to reduced work efficiency.

[0003] To overcome this problem, the existing mainstream solution is to add a set of hydraulic mechanical transmission (HMT) on the basis of the gearbox. This device can achieve stepless speed change when the hydraulic system is working by connecting a group of hydraulic pumps and hydraulic motors in series or in parallel to the gearbox. In this way, the driver can smoothly adjust the speed and torque of the tractor according to actual needs, thereby improving the convenience and work efficiency of operation. However, although the HMT transmission can solve the problem of stepless speed change to a certain extent, it also brings new challenges. For example, the introduction of the hydraulic system may lead to increased complexity of the overall system, increased maintenance costs, and in some cases, the efficiency of the hydraulic system may not be as good as that of a pure mechanical system. Therefore, how to achieve stepless speed change of some gears while maintaining efficient mechanical transmission is still a technical problem that needs to be solved urgently.

[0004] In summary, although the tractor gearbox in the prior art has a high transmission efficiency, it is complex to operate and has limited efficiency because it can only perform stepped speed change. Although the existing HMT transmission device can achieve stepless speed change, it also increases the system complexity and maintenance cost. Therefore, it is necessary to develop a new type of speed change system that can achieve stepless speed change of some gears without significantly increasing the complexity of the system, thereby improving the convenience of tractor operation and work efficiency. Summary of the invention

[0005] The object of the present invention is to provide a vehicle transmission system which is simple to operate and can quickly achieve partial stepless speed change in view of the above problems.

[0006] To achieve the above-mentioned purpose, the present invention discloses a vehicle transmission system for realizing partial stepless speed change, the structural features of which include a main transmission shaft and a sub-transmission, the input end of the sub-transmission is provided with a sub-driven shaft, the main transmission shaft is sleeved with a hydraulic transmission wheel and a mechanical transmission wheel, the sub-driven shaft is fixedly connected with a speed change wheel and a driven wheel for power transmission with the mechanical transmission wheel, and also includes a power combining device for controlling the power transmission between the hydraulic transmission wheel and the main transmission shaft or controlling the power transmission between the mechanical transmission wheel and the main transmission shaft, and also includes a variable pump for power transmission with the hydraulic transmission wheel and a hydraulic motor connected to the variable pump through a hydraulic pipeline, the hydraulic motor is connected to the speed change wheel power, and the output end of the sub-transmission is provided with a power output shaft for power transmission with the vehicle wheel group.

[0007] After adopting the above structure, the hydraulic transmission wheel and mechanical transmission wheel on the main transmission shaft are responsible for hydraulic and mechanical power transmission modes respectively. The optimal transmission mode can be selected under different working conditions to improve the overall transmission efficiency. The power combination device can flexibly control the power transmission between the hydraulic transmission wheel and the mechanical transmission wheel and the main transmission shaft. This flexible speed control method enables the vehicle to respond to the driver's operating instructions more quickly and improves the vehicle's handling performance. The variable pump and the hydraulic motor are connected through hydraulic pipelines and form a complete hydraulic transmission circuit with the hydraulic transmission wheel to achieve stepless speed change of the auxiliary driven shaft and the auxiliary transmission. This design can achieve stepless speed change by only changing a smaller structure on the basis of not changing the transmission structure and size of the existing gearbox.

[0008] Preferably, a plurality of mechanical transmission wheels are sleeved at intervals on the main transmission shaft, and a plurality of driven wheels corresponding to the mechanical transmission wheels are fixedly connected to the secondary driven shaft, and each driven wheel is connected to the corresponding mechanical transmission wheel in power. Through the one-to-one correspondence between the plurality of mechanical transmission wheels and the plurality of driven wheels, multi-gear adjustment of the mechanical transmission can be achieved.

[0009] Preferably, each pair of mechanical transmission wheels and driven wheels arranged on the main transmission shaft and the secondary driven shaft have different transmission ratios. Through the different transmission speed ratios of each group of one-to-one corresponding mechanical transmission wheels and driven wheels, when the main transmission shaft rotates, the power coupling device can realize the conversion of multiple gears and different speeds of mechanical transmission.

[0010] Preferably, the hydraulic transmission wheel, mechanical transmission wheel, speed change wheel and driven wheel are all gears, and the mechanical transmission wheel is meshed with the driven wheel. By making the above-mentioned multiple wheel bodies all gears, the stability of power transmission between the wheel sets can be improved and the spatial structure can be more compact.

[0011] Preferably, the number of mechanical transmission wheels and driven wheels are both 3, and the 3 mechanical transmission wheels cooperate with the 3 driven wheels to realize the mechanical transmission of the 3 gears of the vehicle, and cooperate with the hydraulic transmission wheels to constitute the commonly used four-speed shifting operation of the vehicle.

[0012] Preferably, the power combination device includes two synchronizers, the first synchronizer can control the power transmission between the hydraulic transmission wheel and the main transmission shaft, the first synchronizer also controls the power transmission between the mechanical transmission wheel adjacent to the hydraulic transmission wheel and the main transmission shaft, and the second synchronizer controls the power transmission between any one of the other two mechanical transmission wheels and the main transmission shaft. The two synchronizers can respectively control the switching of the two mechanical transmission wheels and the gear adjustment of the mechanical transmission and the hydraulic transmission.

[0013] Preferably, a first driving wheel connected to the hydraulic transmission wheel power is arranged on the input shaft of the variable displacement pump, and a second driving wheel connected to the transmission wheel power is arranged on the driving shaft of the hydraulic motor.

[0014] Preferably, the first drive wheel is a gear provided on the input shaft of the variable displacement pump, and the second drive wheel is a gear provided on the drive shaft of the hydraulic motor.

[0015] Preferably, the power output shaft is kinetically connected to a differential that cooperates with the vehicle wheelset.

[0016] Preferably, the auxiliary transmission includes a plurality of gears.

[0017] To sum up, the beneficial effects of the present invention are: the present invention is easy to operate, has a simple and compact spatial structure, and can quickly realize partially stepless speed change of the vehicle. The hydraulic transmission wheel and the mechanical transmission wheel on the main transmission shaft are responsible for the hydraulic and mechanical power transmission modes respectively. The optimal transmission mode can be selected under different working conditions to improve the overall transmission efficiency. The power transmission between the hydraulic transmission wheel and the mechanical transmission wheel and the main transmission shaft can be flexibly controlled through the power combining device. This flexible speed change control method enables the vehicle to respond to the driver's operating instructions more quickly, thereby improving the vehicle's handling performance. The variable pump and the hydraulic motor are connected through hydraulic pipelines and form a complete hydraulic transmission circuit with the hydraulic transmission wheel to realize stepless speed change of the secondary driven shaft and the auxiliary transmission. This design can achieve stepless speed change by only changing a smaller structure on the basis of the existing gearbox without changing the transmission structure and size. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0019] In the figure: 1. Main drive shaft; 2. Auxiliary transmission; 3. Auxiliary driven shaft; 4. Hydraulic transmission wheel; 5. Mechanical transmission wheel; 6. Speed ​​change wheel; 7. Driven wheel; 8. Power coupling device; 9. Variable displacement pump; 10. Hydraulic motor; 11. Power output shaft; 12. First drive wheel; 13. Second drive wheel; 14. Differential; 15. Synchronizer. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0021] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0022] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] The following is a description of preferred embodiments of the present invention with reference to the accompanying drawings.

[0024] like Figure 1 As shown, the present invention includes a main transmission shaft 1 and a sub-transmission 2, and a sub-driven shaft 3 is arranged at the input end of the sub-transmission 2. The sub-transmission 2 includes a plurality of gears. Usually, the sub-transmission 2 has four gears. When designed, a hydraulic transmission wheel 4 and a mechanical transmission wheel 5 are sleeved on the main transmission shaft 1, and a speed change wheel 6 and a driven wheel 7 for power transmission with the mechanical transmission wheel 5 are fixedly connected to the sub-driven shaft 3. At the same time, it also includes a power combination device 8 for controlling the power transmission between the hydraulic transmission wheel 4 and the main transmission shaft 1 or controlling the power transmission between the mechanical transmission wheel 5 and the main transmission shaft 1 During manufacturing, a plurality of mechanical transmission wheels 5 are sleeved at intervals on the main transmission shaft 1, wherein a plurality of driven wheels 7 corresponding to the mechanical transmission wheels 5 are fixedly connected to the secondary driven shaft 3, each of the above-mentioned driven wheels 7 is power-connected to the corresponding mechanical transmission wheel 5, and each pair of mechanical transmission wheels 5 and driven wheels 7 arranged on the main transmission shaft 1 and the secondary driven shaft 3 has a different transmission ratio. In this way, through the different transmission speed ratios of each group of one-to-one corresponding mechanical transmission wheels 5 and driven wheels 7, when the main transmission shaft 1 rotates, the power coupling device 8 can realize the conversion of multiple gears and different speeds of mechanical transmission.

[0025] Usually, three mechanical transmission wheels 5 are sleeved on the main transmission shaft 1, and three driven wheels 7 corresponding to the mechanical transmission wheels 5 are fixedly connected to the auxiliary driven shaft 3, and each group of corresponding driven wheels 7 is connected to the mechanical transmission wheel 5 by power, so that the three mechanical transmission wheels 5 cooperate with the three driven wheels 7 to realize the mechanical transmission of the three gears of the vehicle, and cooperate with the hydraulic transmission wheel 4 to constitute the commonly used four-speed shifting operation of the vehicle; the above-mentioned power combination device 8 includes two synchronizers 15, the first synchronizer 15 can control the power transmission between the hydraulic transmission wheel 4 and the main transmission shaft 1, and the first synchronizer 15 also controls the mechanical transmission wheel 5 adjacent to the hydraulic transmission wheel 4 and the main transmission shaft 1 Power transmission, the second synchronizer 15 controls the power transmission between any one of the other two mechanical transmission wheels 5 and the main transmission shaft 1, so that the switching of the two mechanical transmission wheels 5 and the gear adjustment of the mechanical transmission and the hydraulic transmission can be controlled respectively through the two synchronizers 15. During production, the above-mentioned hydraulic transmission wheel 4, mechanical transmission wheel 5, speed change wheel 6 and driven wheel 7 are all gears, wherein the mechanical transmission wheel 5 is meshed with the driven wheel 7. In this way, by using the above-mentioned multiple wheel bodies as gears, the stability of power transmission between the wheel sets can be improved and the spatial structure can be more compact. Of course, the power transmission method of the above-mentioned mechanical transmission wheel 5 and the driven wheel 7 can also be driven by belts.

[0026] The system also includes a variable pump 9 for transmitting power to the hydraulic transmission wheel 4 and a hydraulic motor 10 connected to the variable pump 9 through a hydraulic pipeline, wherein the hydraulic motor 10 is connected to the speed change wheel 6 by power. During design, a first drive wheel 12 connected to the power of the hydraulic transmission wheel 4 is provided on the input shaft of the variable pump 9, and a second drive wheel 13 connected to the power of the speed change wheel 6 is provided on the drive shaft of the hydraulic motor 10. During manufacturing, the first drive wheel 12 is a gear that rotates coaxially with the drive rod of the variable pump 9, and the second drive wheel 13 is a gear that rotates coaxially with the drive shaft of the hydraulic motor 10, so that the first drive wheel 12 is meshed with the hydraulic transmission wheel 4, and the second drive wheel 13 is meshed with the speed change wheel 6. In this way, power transmission through gears can effectively save usage space and make the structure more compact and easy to disassemble and assemble.

[0027] A power output shaft 11 for transmitting power to the vehicle wheel set is provided at the output end of the auxiliary transmission 2. The power output shaft 11 is power-connected to a differential 14 matched with the vehicle wheel set. A power output shaft 11 for transmitting power to the vehicle wheel set is provided at the output end of the auxiliary transmission 2. This design ensures precise control of power output, can flexibly adjust power output according to the actual driving conditions of the vehicle, and improves the driving stability and handling performance of the vehicle. At the same time, the power output shaft 11 is connected to the differential 14 matched with the vehicle wheel set. This design can effectively distribute power to the left and right wheels, ensure the speed difference between the inner and outer wheels of the vehicle when turning, avoid tire slippage or excessive wear, and improve the driving safety and comfort of the vehicle.

[0028] When in use, during light-load operation, by using the synchronizer 15 to engage the gear position at the hydraulic transmission wheel 4, the main transmission shaft 1 drives the hydraulic transmission wheel 4 to rotate and obtain power, thereby driving the first drive wheel 12 meshing with the dynamic hydraulic transmission wheel 4, and converting the mechanical power into hydraulic power through the variable pump 9, and then through the hydraulic motor 10 matched with the variable pump 9, the second drive wheel 13 on the hydraulic motor 10 meshes with the speed change wheel 6 to transmit the power to the secondary driven shaft 3, thereby transmitting the power to the auxiliary transmission 2. In this way, the speed of the speed change wheel 6 is adjusted by controlling the flow of the variable pump 9. In this mode, combined with the 4 gear positions of the auxiliary transmission 2, the interval The continuously variable speed change enables the speed change device for the working vehicle to achieve continuously variable speed change by only changing a small structure on the basis of the existing gearbox without changing the transmission structure and size; and when heavy-load operation is required, the transmission efficiency needs to be improved. When the gears at the other mechanical transmission wheels 5 are engaged by using the synchronizer 15, since each pair of mechanical transmission wheels 5 and the driven wheels 7 arranged on the main transmission shaft 1 and the auxiliary driven shaft 3 have different transmission ratios and each group of corresponding mechanical transmission wheels 5 is meshed with the driven wheels 7, the mechanical power is transmitted to a sub-gearbox, so that the vehicle can achieve stepped speed change in this mode. This mode can have high efficiency and low power loss under heavy-load conditions.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle transmission system for achieving partial continuously variable speed change, characterized in that: The invention comprises a main transmission shaft (1) and a sub-transmission (2), wherein the input end of the sub-transmission (2) is provided with a sub-driven shaft (3), the main transmission shaft (1) is sleeved with a hydraulic transmission wheel (4) and a mechanical transmission wheel (5), the sub-driven shaft (3) is fixedly connected with a speed change wheel (6) and a driven wheel (7) for power transmission with the mechanical transmission wheel (5), and further comprises a power combining device (8) for controlling power transmission between the hydraulic transmission wheel (4) and the main transmission shaft (1) or controlling power transmission between the mechanical transmission wheel (5) and the main transmission shaft (1), and further comprises a variable pump (9) for power transmission with the hydraulic transmission wheel (4) and a hydraulic motor (10) connected to the variable pump (9) through a hydraulic pipeline, the hydraulic motor (10) being power-connected with the speed change wheel (6), and the output end of the sub-transmission (2) is provided with a power output shaft (11) for power transmission with a vehicle wheel set.

2. The vehicle transmission system for realizing partial continuously variable speed change according to claim 1, characterized in that: The main transmission shaft (1) is sleeved with a plurality of mechanical transmission wheels (5) at intervals, and the auxiliary driven shaft (3) is fixedly connected with a plurality of driven wheels (7) corresponding one to one with the mechanical transmission wheels (5), and each driven wheel (7) is power-connected to the corresponding mechanical transmission wheel (5).

3. The vehicle transmission system for realizing partial continuously variable speed change as claimed in claim 2, characterized in that: Each pair of mechanical transmission wheels (5) and driven wheels (7) arranged on the main transmission shaft (1) and the secondary driven shaft (3) has a different transmission ratio.

4. A vehicle transmission system for realizing partial continuously variable speed change according to any one of claims 1 to 3, characterized in that: The hydraulic transmission wheel (4), the mechanical transmission wheel (5), the speed change wheel (6) and the driven wheel (7) are all gears, and the mechanical transmission wheel (5) is meshed with the driven wheel (7).

5. The vehicle transmission system for realizing partial continuously variable speed change as claimed in claim 2, characterized in that: The number of the mechanical transmission wheels (5) and the number of the driven wheels (7) are both three.

6. The vehicle transmission system for realizing partial continuously variable speed change as claimed in claim 5, characterized in that: The power coupling device (8) comprises two synchronizers (15), wherein the first synchronizer (15) can control the power transmission between the hydraulic transmission wheel (4) and the main transmission shaft (1), the first synchronizer (15) also controls the power transmission between the mechanical transmission wheel (5) adjacent to the hydraulic transmission wheel (4) and the main transmission shaft (1), and the second synchronizer (15) controls the power transmission between any one of the other two mechanical transmission wheels (5) and the main transmission shaft (1).

7. The vehicle transmission system for realizing partial continuously variable speed change according to claim 1, characterized in that: A first driving wheel (12) connected to the hydraulic transmission wheel (4) by power is arranged on the driving rod of the variable displacement pump (9), and a second driving wheel (13) connected to the speed change wheel (6) by power is arranged on the driving shaft of the hydraulic motor (10).

8. The vehicle transmission system for realizing partial continuously variable speed change according to claim 6, characterized in that: The first drive wheel (12) is a gear provided on an input shaft of a variable displacement pump (9), and the second drive wheel (13) is a gear provided on a drive shaft of a hydraulic motor (10).

9. The vehicle transmission system for realizing partial continuously variable speed change according to claim 1, characterized in that: The power output shaft (11) is dynactively connected to a differential (14) that matches the vehicle wheel set.

10. The vehicle transmission system for realizing partial continuously variable speed change according to claim 1, characterized in that: The auxiliary transmission (2) comprises a plurality of gear positions.

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