Parallel shaft type tractor CVT power assembly

Abstract

The utility model relates to the technical field of power assemblies, in particular to a parallel shaft type tractor CVT (continuously variable transmission) power assembly, which comprises an engine, a generator, a driving motor and a gearbox, the output end of the engine is in transmission connection with a first driving shaft, and the first driving shaft is in transmission connection with a PTO (power take-off) shaft; a rotor of the generator is in coaxial transmission connection with a second driving shaft parallel to the first driving shaft, and the second driving shaft is in accelerated transmission fit with the first driving shaft through a first transmission mechanism; and a power input shaft in transmission fit with the driving motor is arranged on the gearbox. Through the structure, the generator is independently mounted, and the first transmission mechanism accelerates and transmits the rotating speed output by the first driving shaft to the second driving shaft, so that the rotating speed of a rotor in the generator does not only depend on the rotating speed of the first driving shaft any more, but can be adjusted through the first driving mechanism; therefore, the power generation efficiency of the generator is improved.

Description

Technical Field

[0001] This utility model relates to the field of powertrain technology, specifically to a parallel-shaft tractor CVT powertrain. Background Technology

[0002] Traditional tractors mostly use manual shifting systems. When tractors are working in the field, they often need to stop frequently to shift gears to meet the requirements of implement operation and traction. This results in low work efficiency and unstable work quality. At the same time, the engine speed is directly related to the vehicle speed. Changes in the overall vehicle speed cause large fluctuations in engine speed. The engine cannot operate within a stable speed range, resulting in high fuel consumption, poor emissions, and significant vibration and wear.

[0003] With the rapid development of the new energy vehicle industry, tractor R&D personnel, drawing on their experience in the new energy vehicle field, have developed a hybrid tractor CVT powertrain. This system uses a drive motor to propel the tractor, allowing for direct control of forward and reverse movement by controlling the drive motor's rotational direction, and controlling the tractor's speed by adjusting the output shaft speed. This results in a more stable and fuel-efficient powertrain. Since tractors typically also need to transmit power to agricultural implements, which often require low-speed, high-torque drive, an engine is still required.

[0004] Therefore, existing hybrid tractor CVT powertrains typically include an engine, whose drive shaft drives the PTO shaft to rotate, thereby powering the implements. In existing technology, the PTO shaft also passes through the drive motor and gearbox (but is not linked to either). A generator is also directly mounted on the engine's drive shaft. When the engine rotates, the drive shaft drives the generator to produce electricity. This electricity can be stored in an energy storage unit, and when needed, the stored energy can be supplied to the drive motor.

[0005] In existing technologies, the engine's drive shaft often passes directly through the generator, meaning the generator's rotor rotates synchronously with the engine's drive shaft. However, agricultural machinery typically requires relatively low speeds, meaning the engine's output speed is often quite low. Since the generator's rotor is synchronously driven with the engine's drive shaft, the generator's power generation efficiency is low, and it cannot fully utilize the power output from the engine's drive shaft. Utility Model Content

[0006] To address the aforementioned problems, this utility model provides a parallel-shaft tractor CVT powertrain to solve the problem of low generator power generation efficiency caused by the synchronous transmission between the generator rotor and the engine drive shaft in the prior art.

[0007] This utility model is achieved using the following technical solution: a parallel-shaft tractor CVT powertrain, including an engine, a generator, a drive motor, and a gearbox. The output end of the engine is driven by a first drive shaft, and the first drive shaft is driven by a PTO shaft. The rotor of the generator is coaxially driven by a second drive shaft parallel to the first drive shaft. The second drive shaft is accelerated and driven by the first drive shaft through a first transmission mechanism. The gearbox is provided with a power input shaft that drives the drive motor.

[0008] With the above structure, the generator is installed independently. During installation, it is only necessary to ensure that the second drive shaft is parallel to the first drive shaft. Then, the speed output by the first drive shaft is accelerated and transmitted to the second drive shaft through the first transmission mechanism. As a result, the speed of the rotor in the generator no longer depends solely on the speed of the first drive shaft, but can be adjusted by the first drive mechanism, so that the speed of the rotor in the generator is faster, thereby improving the generator's power generation efficiency and making fuller use of the power output by the engine.

[0009] Preferably, the first transmission mechanism includes a first gear coaxially fixedly connected to the first drive shaft, and a second gear coaxially fixedly connected to the second drive shaft, meshing with the first gear. The first gear has a larger number of teeth than the second gear. Through the transmission between the larger first gear and the smaller second gear, when the first drive shaft drives the first gear to rotate one revolution, the second gear can drive the second drive shaft to rotate multiple revolutions. This allows the rotor to rotate multiple revolutions when the first drive shaft rotates one revolution, resulting in higher power generation efficiency.

[0010] Preferably, the end of the first drive shaft furthest from the engine is provided with a spline sleeve, and the end of the PTO shaft closest to the engine is in transmission engagement with the spline sleeve. The spline sleeve allows the first drive shaft to drive the PTO shaft to rotate synchronously.

[0011] Preferably, the power input shaft is a hollow shaft, and the PTO shaft passes through the middle of the power input shaft. By making the power output shaft a hollow shaft and having the PTO shaft pass through its middle, the installation space of this device can be made more compact, saving installation space.

[0012] Preferably, the drive motor has a hollow output shaft in the middle, and the output shaft of the drive motor is coaxially and fixedly connected to the power input shaft. The PTO shaft passes through the middle of the drive motor output shaft. By directly connecting the output shaft of the drive motor to the power input shaft of the gearbox, the drive motor responds faster when driving the tractor, and has a simple structure, low failure rate, and is more convenient to maintain.

[0013] Preferably, the drive motor has an output shaft in the middle, and a third drive shaft parallel to the power input shaft is coaxially and fixedly connected to the output shaft. The third drive shaft and the power input shaft are connected by a second transmission mechanism. The second transmission mechanism allows the drive motor to be mounted on one side of the power input shaft, making the installation position more flexible. Furthermore, the parallel installation of the third drive shaft, the second drive shaft, and the power input shaft significantly reduces the axial installation space.

[0014] Preferably, the second transmission mechanism includes a third gear coaxially fixedly connected to the third drive shaft, and a fourth gear coaxially fixedly connected to the power input shaft, meshing with the third gear, the fourth gear having a greater number of teeth than the third gear. Through the transmission between the fourth and third gears, this device can effectively increase the maximum torque output by the drive motor, making it easier to handle road conditions such as uphill climbs.

[0015] Preferably, the drive motor has a hollow output shaft in its middle section, and a hollow fourth drive shaft is coaxially fixedly connected to the output shaft of the drive motor. The fourth drive shaft and the power input shaft are coaxially driven by a planetary gear set. The PTO shaft passes through the middle of the drive motor output shaft and the middle of the fourth drive shaft. Through the reduction transmission of the planetary gear set, the maximum torque output by the drive motor can be effectively increased, thereby facilitating the tractor in this device to cope with road conditions such as uphill climbs.

[0016] Preferably, the planetary gear set includes a ring gear, a sun gear fixedly connected to the fourth drive shaft in the middle of the ring gear, a plurality of planet gears meshing with the sun gear and the ring gear between the sun gear and the ring gear, the plurality of planet gears being connected by a planet carrier, and the planet carrier being fixedly connected to the power input shaft coaxially.

[0017] Preferably, the output shaft of the engine is coaxially fixedly connected to a flywheel, and the flywheel is driven by a clutch to the first drive shaft.

[0018] In summary, the beneficial effects of this invention are as follows: by detaching the generator from the first drive shaft, the rotor speed in the generator no longer depends on the engine's output speed, but can be adjusted through a gear set or other acceleration transmission mechanism, thereby improving the generator's power generation efficiency and fully utilizing the engine's output power. Furthermore, installing the generator parallel to the first drive shaft saves space along the tractor's length, resulting in a more compact and stable powertrain installation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0020] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this utility model;

[0021] Figure 3 This is a schematic diagram of the structure of Embodiment 3 of this utility model.

[0022] In the diagram: 1-Engine; 2-Flywheel; 3-Clutch; 5-First drive shaft; 6-First gear; 7-Second gear; 8-Second drive shaft; 9-Generator; 10-Spline sleeve; 11-PTO shaft; 12-Drive motor; 13-Power input shaft; 14-Gearbox; 15-Rear axle; 16-Third drive shaft; 17-Third gear; 18-Fourth gear; 19-Fourth drive shaft; 20-Sun gear; 21-Planet gears; 22-Planet carrier; 23-Planet gear set. Detailed Implementation

[0023] 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.

[0024] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "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.

[0025] The following is a description of preferred embodiments of the present invention in conjunction with the accompanying drawings. Example 1:

[0026] like Figure 1As shown, this utility model provides a parallel-shaft tractor CVT powertrain, including an engine 1, a generator 9, a drive motor 12, a gearbox 14, and a PTO shaft for transmitting power to the PTO mechanism. A first drive shaft 5 is connected to the output end of the engine 1. Specifically, a flywheel 2 is coaxially fixedly connected to the output shaft of the engine 1. The flywheel 2 and the first drive shaft 5 are driven by a clutch 3. The clutch 3 can control the power connection or disconnection between the flywheel 2 and the first drive shaft 5.

[0027] A PTO shaft 11 is connected to the end of the first drive shaft 5 furthest from the engine 1. Specifically, a spline sleeve 10 is provided at the end of the first drive shaft 5 furthest from the engine 1, with an internal spline inside the spline sleeve 10. An external spline that mates with the spline sleeve 10 is provided at the end of the PTO shaft 11 closest to the engine 1. The PTO shaft 11 and the spline sleeve 10 are inserted into each other. The rotor of the generator 9 is coaxially connected to a second drive shaft 8 parallel to the first drive shaft 5. The second drive shaft 8 is connected to the first drive shaft 5 via a first transmission mechanism for accelerated transmission. A power input shaft 13 is provided on the gearbox 14 for transmission with the drive motor 12.

[0028] The first transmission mechanism described above can employ any method capable of accelerating transmission, such as the accelerating transmission method of a chain and sprocket. In this embodiment, the first transmission mechanism includes a first gear 6 coaxially and fixedly connected to the first drive shaft 5, and a second gear 7 coaxially and fixedly connected to the second drive shaft 8, meshing with the first gear 6. The number of teeth on the first gear 6 is greater than that on the second gear 7.

[0029] By setting the tooth ratio between the first gear 6 and the second gear 7, the second drive shaft can rotate multiple times for the first drive shaft 5 to rotate once, thereby increasing the amount of electricity generated by the generator 9. The electricity generated by the generator 9 can be stored in an energy storage unit for use by the drive motor 12. This is conventional prior art, and those skilled in the art can easily obtain its technology through patents or other means, so it will not be elaborated further here.

[0030] The power input shaft 13 is a hollow shaft, and the PTO shaft 11 passes through the middle of the power input shaft 13. The drive motor 12 has a hollow output shaft in the middle, and the output shaft of the drive motor 12 is coaxially and fixedly connected to the power input shaft 13. The PTO shaft 11 passes through the middle of the output shaft of the drive motor 12.

[0031] When engine 1 is running, it drives the second drive shaft 8 to rotate via the first drive shaft 5, which in turn causes the generator 9 to generate electricity. When it is necessary to control the tractor to move, it is only necessary to control the drive motor 12 to work. The power output by the drive motor 12 is transmitted to the rear wheels via the gearbox 14 and the rear axle 15, thereby controlling the operation of the tractor. Example 2:

[0032] like Figure 2 As shown, the structure in this embodiment is basically the same as that in embodiment one. The only difference between this embodiment and embodiment one is that the drive motor 12 has an output shaft in the middle. The output shaft of the drive motor 12 is coaxially fixedly connected to a third drive shaft 16 parallel to the power input shaft. The third drive shaft 16 and the power input shaft 13 are connected by a second transmission mechanism.

[0033] The second transmission structure can also adopt the sprocket and chain transmission method. However, in this embodiment, the second transmission mechanism includes a third gear 17 coaxially fixedly connected to the third drive shaft 16, and a fourth gear 18 coaxially fixedly connected to the power input shaft 13, which meshes with the third gear 17. The number of teeth of the fourth gear 18 is greater than that of the third gear 17.

[0034] In this embodiment, the axes of the first drive shaft 5, the second drive shaft 8, and the third drive shaft 16 are three parallel straight lines, that is, the engine 1, the generator 9, and the drive motor 12 are not installed on a straight line. This makes the space occupied by the device in the front-rear direction of the tractor smaller, thereby making the powertrain installation more compact and stable. Example 3:

[0035] like Figure 3 As shown, the structure in this embodiment is basically the same as that in embodiment one. The only difference between this embodiment and embodiment one is that: the drive motor 12 has a hollow output shaft in the middle, and the output shaft of the drive motor 12 is coaxially fixedly connected to a hollow fourth drive shaft 19. The fourth drive shaft 19 and the power input shaft 13 are coaxially driven by the planetary gear set 23. The PTO shaft 11 passes through the middle of the output shaft of the drive motor 12 and the middle of the fourth drive shaft 19.

[0036] The planetary gear set 23 mentioned above includes a gear ring, a sun gear 20 which is coaxially and fixedly connected to the fourth drive shaft 19 in the middle of the gear ring, and a number of planet gears 21 that mesh with the sun gear 20 and the gear ring are provided between the sun gear 20 and the gear ring. The number of planet gears 21 are connected by a planet carrier 22, and the planet carrier 22 is coaxially and fixedly connected to the power input shaft 13.

[0037] Whether it is the reduction transmission of the third gear 17 and the fourth gear 18 in Embodiment 2, or the reduction transmission through the planetary gear set 23 in this embodiment, both can effectively improve the maximum torque output by the drive motor 12, thereby facilitating the tractor in this device to cope with road conditions such as uphill.

[0038] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A parallel-shaft tractor CVT powertrain, comprising an engine (1), a generator (9), a drive motor (12), and a gearbox (14), wherein the output end of the engine (1) is drivenly connected to a first drive shaft (5), and the first drive shaft (5) is drivenly connected to a PTO shaft (11), characterized in that, The rotor of the generator (9) is coaxially connected to a second drive shaft (8) parallel to the first drive shaft (5). The second drive shaft (8) is accelerated and driven by the first drive shaft (5) through the first transmission mechanism. The gearbox (14) is provided with a power input shaft (13) that is driven by the drive motor (12).

2. The parallel axis tractor CVT powertrain of claim 1, wherein, The first transmission mechanism includes a first gear (6) coaxially fixedly connected to the first drive shaft (5), and a second gear (7) coaxially fixedly connected to the second drive shaft (8) and meshing with the first gear (6). The number of teeth of the first gear (6) is greater than that of the second gear (7).

3. The parallel-shaft tractor CVT powertrain according to claim 1, characterized in that, The first drive shaft (5) is provided with a spline sleeve (10) at the end away from the engine (1), and the PTO shaft (11) is in transmission cooperation with the spline sleeve (10) at the end close to the engine (1).

4. The parallel axis tractor CVT powertrain of claim 1, wherein, The power input shaft (13) is a hollow shaft, and the PTO shaft (11) passes through the middle of the power input shaft (13).

5. The parallel axis tractor CVT powertrain of claim 4, wherein, The drive motor (12) has a hollow output shaft in the middle. The output shaft of the drive motor (12) is coaxially and fixedly connected to the power input shaft (13). The PTO shaft (11) passes through the middle of the output shaft of the drive motor (12).

6. The parallel axis tractor CVT powertrain of claim 4, wherein, The drive motor (12) has an output shaft in the middle. The output shaft of the drive motor (12) is coaxially fixedly connected to a third drive shaft (16) parallel to the power input shaft. The third drive shaft (16) and the power input shaft (13) are connected by a second transmission mechanism.

7. The parallel axis tractor CVT powertrain of claim 6, wherein, The second transmission mechanism includes a third gear (17) coaxially fixedly connected to the third drive shaft (16), and a fourth gear (18) coaxially fixedly connected to the power input shaft (13) and meshing with the third gear (17). The number of teeth of the fourth gear (18) is greater than that of the third gear (17).

8. The parallel axis tractor CVT powertrain of claim 4, wherein, The drive motor (12) has a hollow output shaft in the middle. The output shaft of the drive motor (12) is coaxially fixedly connected to a hollow fourth drive shaft (19). The fourth drive shaft (19) and the power input shaft (13) are coaxially driven by a planetary gear set (23). The PTO shaft (11) passes through the middle of the output shaft of the drive motor (12) and the middle of the fourth drive shaft (19).

9. The parallel-shaft tractor CVT powertrain according to claim 8, characterized in that, The planetary gear set (23) includes a gear ring, a sun gear (20) is provided in the middle of the gear ring and is coaxially fixedly connected to the fourth drive shaft (19), and a number of planet gears (21) are provided between the sun gear (20) and the gear ring, which mesh with the sun gear (20) and the gear ring. The number of planet gears (21) are connected by a planet carrier (22), and the planet carrier (22) is coaxially fixedly connected to the power input shaft (13).

10. The parallel axis tractor CVT powertrain of any of claims 1-9, wherein, The output shaft of the engine (1) is coaxially fixedly connected to a flywheel (2), and the flywheel (2) is driven by the first drive shaft (5) through a clutch (3).

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