Vehicle transmission system capable of realizing partial stepless speed change

Abstract

The utility model 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 changing device is convenient to operate and simple and compact in space structure, and stepless speed changing can be achieved only by changing a small structure on the basis that a transmission structure and the size of an existing speed changing box are not changed.

Description

Technical Field

[0001] This utility model relates to the field of agricultural machinery technology, specifically to a vehicle transmission system that achieves partial continuously variable transmission. Background Technology

[0002] In traditional mechanical transmission systems, tractor gearboxes typically achieve a transmission efficiency of 95%-97% due to their highly efficient energy transmission characteristics. However, this mechanical transmission method has a significant limitation: it can only achieve stepped gear changes, not continuously variable transmissions. This means that the driver needs to frequently switch gears during operation to adapt to different working conditions and load requirements, which not only increases the complexity of operation but may also lead to a decrease in work efficiency.

[0003] To overcome this problem, the current mainstream solution is to add a hydraulic mechanical transmission (HMT) to the gearbox. This device connects a hydraulic pump and a hydraulic motor in series or parallel with the gearbox, enabling continuously variable transmission (CVT) when the hydraulic system is operating. This allows the driver to smoothly adjust the tractor's speed and torque as needed, improving operational convenience and work efficiency. However, while HMT can solve the CVT problem to some extent, it also introduces new challenges. For example, the introduction of a hydraulic system may increase the overall system complexity, raise maintenance costs, and in some cases, the efficiency of a hydraulic system may be lower than that of a purely mechanical system. Therefore, how to achieve CVT with some gears while maintaining efficient mechanical transmission remains a pressing technical challenge.

[0004] In summary, while existing tractor gearboxes offer high transmission efficiency, their limited range and reliance on stepped gear changes result in complex operation and inefficient performance. While existing HMT (Hybrid Transmission Machine) systems can achieve continuously variable transmission (CVT), this increases system complexity and maintenance costs. Therefore, it is necessary to develop a novel transmission system capable of partial CVT without significantly increasing system complexity, thereby improving the ease of operation and work efficiency of tractors. Utility Model Content

[0005] The purpose of this invention is to provide a vehicle transmission system that is simple to operate and can quickly achieve partial continuously variable transmission (CVT) in response to the above problems.

[0006] To achieve the above objectives, this utility model discloses a vehicle transmission system that realizes partial continuously variable transmission (CVT). Its structural features include a main drive shaft and a secondary transmission. The input end of the secondary transmission is provided with a secondary driven shaft. A hydraulic transmission wheel and a mechanical transmission wheel are sleeved on the main drive shaft. A gear shift wheel and a driven wheel that transmits power to the mechanical transmission wheel are fixedly connected to the secondary driven shaft. The system also includes a power coupling device for controlling the power transmission between the hydraulic transmission wheel and the main drive shaft, or for controlling the power transmission between the mechanical transmission wheel and the main drive shaft. Furthermore, it includes a variable displacement pump that transmits power to the hydraulic transmission wheel and a hydraulic motor connected to the variable displacement pump via a hydraulic pipeline. The hydraulic motor is poweredly connected to the gear shift wheel. The output end of the secondary transmission is provided with a power output shaft that transmits power to the vehicle's wheel set.

[0007] With the above structure, the hydraulic and mechanical transmission wheels on the main drive shaft are responsible for the hydraulic and mechanical power transmission methods respectively. The optimal transmission method can be selected under different working conditions, improving the overall transmission efficiency. The power combination device can flexibly control the power transmission between the hydraulic and mechanical transmission wheels and the main drive shaft. This flexible speed control method allows the vehicle to respond to the driver's operating commands more quickly, improving the vehicle's handling performance. The variable pump and hydraulic motor are connected through hydraulic lines and form a complete hydraulic transmission circuit with the hydraulic transmission wheels, thereby realizing continuously variable transmission between the secondary driven shaft and the secondary gearbox. This design can achieve continuously variable transmission by only slightly modifying the structure without changing the transmission structure and size of the existing gearbox.

[0008] Preferably, the main drive shaft has multiple mechanical transmission wheels spaced apart, and the secondary driven shaft has multiple driven wheels that correspond one-to-one with the mechanical transmission wheels. Each driven wheel is poweredly connected to its corresponding mechanical transmission wheel. By having multiple mechanical transmission wheels and multiple driven wheels in a one-to-one correspondence, multi-level adjustment of the mechanical transmission can be achieved.

[0009] Preferably, each pair of mechanical transmission wheels on the main drive shaft and the secondary driven shaft has a different transmission ratio to the driven wheel. By using the different transmission speed ratios of each pair of corresponding mechanical transmission wheels and driven wheels, multiple speeds of mechanical transmission can be switched through the power coupling device when the main drive shaft rotates.

[0010] Preferably, the hydraulic transmission wheel, the mechanical transmission wheel, the speed-changing wheel, and the driven wheel are all gears. The mechanical transmission wheel meshes with the driven wheel. By having multiple wheel bodies that are all gears, the stability of power transmission between wheel sets can be improved and the spatial structure can be more compact.

[0011] Preferably, there are three mechanical transmission wheels and three driven wheels. The three mechanical transmission wheels and three driven wheels work together to realize the mechanical transmission of three gears in the vehicle. In conjunction with the hydraulic transmission wheels, it can form the commonly used four-speed shifting operation of the vehicle.

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

[0013] Preferably, the input shaft of the variable pump is provided with a first drive wheel that is powered by the hydraulic transmission wheel, and the drive shaft of the hydraulic motor is provided with a second drive wheel that is powered by the speed change wheel.

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

[0015] Preferably, the power take-off shaft is powered by a differential that matches the vehicle's wheel set.

[0016] Preferably, the secondary transmission includes multiple gears.

[0017] In summary, the beneficial effects of this utility model are as follows: This utility model is easy to operate, has a simple and compact spatial structure, and can quickly achieve continuously variable transmission (CVT) in parts of a vehicle. The hydraulic and mechanical transmission wheels on the main drive shaft are responsible for the hydraulic and mechanical power transmission methods respectively, allowing for the selection of the optimal transmission method under different working conditions, thus improving overall transmission efficiency. Furthermore, the power combination device allows for flexible control of the power transmission between the hydraulic and mechanical transmission wheels and the main drive shaft. This flexible speed control method enables the vehicle to respond more quickly to the driver's commands, improving vehicle handling performance. The variable pump and hydraulic motor are connected through hydraulic lines and form a complete hydraulic transmission circuit with the hydraulic transmission wheels, thereby achieving CVT between the secondary driven shaft and the secondary gearbox. This design achieves CVT by only slightly altering the structure of the existing gearbox without changing its transmission structure and dimensions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0019] In the diagram: 1. Main drive shaft; 2. Auxiliary transmission; 3. Auxiliary driven shaft; 4. Hydraulic transmission wheel; 5. Mechanical transmission wheel; 6. Gearbox; 7. Driven wheel; 8. Power coupling device; 9. Variable displacement pump; 10. Hydraulic motor; 11. Power take-off shaft; 12. First drive wheel; 13. Second drive wheel; 14. Differential; 15. Synchronizer. Detailed Implementation

[0020] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly, for example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

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

[0024] like Figure 1 As shown, this utility model includes a main drive shaft 1 and an auxiliary transmission 2. An auxiliary driven shaft 3 is provided at the input end of the auxiliary transmission 2. The auxiliary transmission 2 includes multiple gears; typically, it has four gears. In the design, a hydraulic transmission wheel 4 and a mechanical transmission wheel 5 are sleeved on the main drive shaft 1, while a gear shift wheel 6 and a driven wheel 7 that transmits power to the mechanical transmission wheel 5 are fixedly connected to the auxiliary driven shaft 3. It also includes a power coupling device for controlling the power transmission between the hydraulic transmission wheel 4 and the main drive shaft 1, or for controlling the power transmission between the mechanical transmission wheel 5 and the main drive shaft 1. 8. During manufacturing, multiple mechanical transmission wheels 5 are spaced and sleeved on the main drive shaft 1. Multiple driven wheels 7, corresponding one-to-one with the mechanical transmission wheels 5, are fixed on the auxiliary driven shaft 3. Each driven wheel 7 is poweredly connected to the corresponding mechanical transmission wheel 5. Moreover, the transmission ratio of each pair of mechanical transmission wheels 5 and driven wheels 7 on the main drive shaft 1 and the auxiliary driven shaft 3 is different. In this way, by using the different transmission speed ratios of each pair of corresponding mechanical transmission wheels 5 and driven wheels 7, multiple speeds of mechanical transmission can be switched through the power coupling device 8 when the main drive shaft 1 rotates.

[0025] Typically, three mechanical transmission wheels 5 are sleeved on the main drive shaft 1, and three driven wheels 7, each corresponding to one of the mechanical transmission wheels 5, are fixedly connected to the auxiliary driven shaft 3. Each set of corresponding driven wheels 7 is powered by the mechanical transmission wheels 5. In this way, the three mechanical transmission wheels 5 and the three driven wheels 7 cooperate with each other to realize the mechanical transmission of the vehicle's three gears. In conjunction with the hydraulic transmission wheel 4, it can form the commonly used four-speed shifting operation of the vehicle. The aforementioned power coupling device 8 includes two synchronizers 15. The first synchronizer 15 can control the power transmission between the hydraulic transmission wheel 4 and the main drive shaft 1. The first synchronizer 15 also controls the mechanical transmission wheel 5 adjacent to the hydraulic transmission wheel 4 and the main drive shaft 1. For power transmission, the second synchronizer 15 controls the power transmission between any one of the other two mechanical transmission wheels 5 and the main drive shaft 1. In this way, the two synchronizers 15 can control the switching of the two mechanical transmission wheels 5 and the gear adjustment of mechanical transmission and hydraulic transmission respectively. During manufacturing, the hydraulic transmission wheel 4, mechanical transmission wheel 5, gear shift wheel 6 and driven wheel 7 mentioned above are all gears. Among them, the mechanical transmission wheel 5 and the driven wheel 7 mesh with each other. By having all the above wheels as gears, the stability of power transmission between the wheel set can be improved and the spatial structure can be more compact. Of course, the power transmission between the mechanical transmission wheel 5 and the driven wheel 7 can also be achieved through belt transmission.

[0026] The system also includes a variable pump 9 that transmits power to the hydraulic transmission wheel 4 and a hydraulic motor 10 connected to the variable pump 9 via hydraulic lines. The hydraulic motor 10 is powered by a gear shift wheel 6. In the design, a first drive wheel 12 powered by the hydraulic transmission wheel 4 is installed on the input shaft of the variable pump 9, while a second drive wheel 13 powered by the gear shift wheel 6 is installed on the drive shaft of the hydraulic motor 10. In 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. This allows the first drive wheel 12 to mesh with the hydraulic transmission wheel 4, and the second drive wheel 13 to mesh with the gear shift wheel 6. This gear-based power transmission effectively saves space, makes the structure more compact, and facilitates assembly and disassembly.

[0027] A power output shaft 11 for power transmission to the vehicle wheelset is provided at the output end of the auxiliary transmission 2. This power output shaft 11 is poweredly connected to a differential 14 that is matched with the vehicle wheelset. This design ensures precise control of power output and allows for flexible adjustment of power output according to the actual driving conditions of the vehicle, thereby improving the vehicle's driving stability and handling performance. At the same time, the power output shaft 11 is connected to the differential 14 that is matched with the vehicle wheelset. This design can effectively distribute power to the left and right wheels, ensuring the difference in rotational speed between the inner and outer wheels when the vehicle is turning, avoiding tire slippage or excessive wear, and improving the vehicle's driving safety and comfort.

[0028] In operation, under light load, by engaging the gear at the hydraulic transmission wheel 4 using the synchronizer 15, the main drive shaft 1 drives the hydraulic transmission wheel 4 to rotate and obtain power. This power then drives the first drive wheel 12, which meshes with the moving hydraulic transmission wheel 4. The variable pump 9 converts the mechanical power into hydraulic power, which is then transmitted to the auxiliary driven shaft 3 via the second drive wheel 13 on the hydraulic motor 10, which meshes with the gear shift wheel 6. This power is then transmitted to the auxiliary transmission 2. By controlling the flow rate of the variable pump 9, the speed of the gear shift wheel 6 can be adjusted. In this mode, combined with the four gears of the auxiliary transmission 2, range... The continuously variable transmission (CVT) allows the transmission device of the work vehicle to achieve continuously variable transmission by only slightly modifying the structure without changing the transmission structure and size of the existing gearbox. When heavy-duty operation is required, it is necessary to improve the transmission efficiency. By using the synchronizer 15 to engage the gears at the other mechanical transmission wheels 5, since the transmission ratio of each pair of mechanical transmission wheels 5 and driven wheels 7 on the main drive shaft 1 and the auxiliary driven shaft 3 is different, and each set of one-to-one mechanical transmission wheels 5 and driven wheels 7 meshes, the mechanical power is transmitted to the auxiliary gearbox, so that the vehicle can achieve stepped transmission in this mode. This mode can achieve high efficiency and low power loss under heavy-duty conditions.

[0029] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A vehicle transmission system that achieves partial continuously variable transmission (CVT), characterized in that: The system includes a main drive shaft (1) and a secondary transmission (2). The input end of the secondary transmission (2) is provided with a secondary driven shaft (3). The main drive shaft (1) is fitted with a hydraulic transmission wheel (4) and a mechanical transmission wheel (5). The secondary driven shaft (3) is fixedly connected with a gear shift wheel (6) and a driven wheel (7) that transmits power to the mechanical transmission wheel (5). The system also includes a power coupling device (8) for controlling the power transmission between the hydraulic transmission wheel (4) and the main drive shaft (1) or for controlling the power transmission between the mechanical transmission wheel (5) and the main drive shaft (1). The system also includes a variable pump (9) that transmits power to the hydraulic transmission wheel (4) and a hydraulic motor (10) connected to the variable pump (9) through a hydraulic pipeline. The hydraulic motor (10) is powered to the gear shift wheel (6). The output end of the secondary transmission (2) is provided with a power output shaft (11) that transmits power to the vehicle wheel set.

2. The vehicle transmission system for partial continuously variable transmission as described in claim 1, characterized in that: The main drive shaft (1) is fitted with multiple mechanical drive wheels (5) at intervals, and the auxiliary driven shaft (3) is fixed with multiple driven wheels (7) that correspond one-to-one with the mechanical drive wheels (5). Each driven wheel (7) is poweredly connected to the corresponding mechanical drive wheel (5).

3. The vehicle transmission system for achieving partial continuously variable transmission as described in claim 2, characterized in that: The transmission ratio of each pair of mechanical transmission wheels (5) and driven wheels (7) on the main drive shaft (1) and the secondary driven shaft (3) is different.

4. The vehicle transmission system for achieving partial continuously variable transmission as described in any one of claims 1-3, characterized in that: The hydraulic transmission wheel (4), mechanical transmission wheel (5), speed change wheel (6) and driven wheel (7) are all gears, and the mechanical transmission wheel (5) meshes with the driven wheel (7).

5. The vehicle transmission system for achieving partial continuously variable transmission as described in claim 2, characterized in that: The mechanical transmission wheel (5) and driven wheel (7) are both three in number.

6. The vehicle transmission system for achieving partial continuously variable transmission as described in claim 5, characterized in that: The power coupling device (8) includes two synchronizers (15). The first synchronizer (15) controls the power transmission between the hydraulic transmission wheel (4) and the main drive 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 drive shaft (1). The second synchronizer (15) controls the power transmission between any one of the other two mechanical transmission wheels (5) and the main drive shaft (1).

7. The vehicle transmission system for achieving partial continuously variable transmission as described in claim 1, characterized in that: The variable pump (9) has a first drive wheel (12) that is powered by the hydraulic transmission wheel (4) on its drive rod, and the hydraulic motor (10) has a second drive wheel (13) that is powered by the speed change wheel (6) on its drive shaft.

8. The vehicle transmission system for partial continuously variable transmission as described in claim 7, characterized in that: The first drive wheel (12) is a gear located on the input shaft of the variable pump (9), and the second drive wheel (13) is a gear located on the drive shaft of the hydraulic motor (10).

9. The vehicle transmission system for achieving partial continuously variable transmission as described in claim 1, characterized in that: The power output shaft (11) is powered to a differential (14) that is compatible with the vehicle's wheel set.

10. The vehicle transmission system for achieving partial continuously variable transmission as described in claim 1, characterized in that: The auxiliary transmission (2) includes multiple gears.

Images