Hybrid system and tractor

Abstract

The present invention relates to the technical field of tractors. Disclosed are a hybrid system and a tractor. The hybrid system comprises an engine, a generator, a battery, a driving motor, a power output device, a rear axle, a brake, a first gear shifting device and a power transmission module, wherein the power transmission module comprises a planet gear assembly, a first transmission assembly, a second transmission assembly and a third transmission assembly. An output shaft of the engine is connected to the power output device, the driving motor is in transmission connection with a sun gear, the sun gear is in transmission connection with a planet gear, the planet gear is in transmission connection with a ring gear, and a planet carrier is connected to the planet gear. The engine is connected to the generator, the brake is arranged on the ring gear, and the generator is in transmission connection with the ring gear by means of the first gear shifting device. The planet carrier is connected to the rear axle, the generator is connected to the battery, and the battery is connected to the driving motor. The hybrid system disclosed by the present invention is a simplified system, and saves on costs.

Description

Hybrid powertrain and tractor

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Chinese patent application No. 202410188802.3 filed on February 20, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of tractors, and in particular to a hybrid power system and a tractor. Background Art

[0004] Currently, the majority of tractors on the market are still powered by diesel engines. This traditional diesel tractor coupled with a manual transmission is not only noisy, has significant shift shock, and is inefficient, but also severely pollutes the environment and requires a high level of operator control. Electric tractors, which use electricity to power their vehicles, offer advantages over traditional diesel tractors, such as low emissions, clean operation, low noise levels, and high energy efficiency. However, the technology is still immature and suffers from shortcomings such as limited endurance. Hybrid tractors, which can be powered by both diesel engines and electricity, address the challenges faced by both traditional diesel and electric tractors and are therefore increasingly popular in the market.

[0005] In order to achieve different power drive modes, existing hybrid tractors usually need to be equipped with a transfer case or a PTO motor. However, adding a transfer case or a PTO motor not only increases the complexity of the system, but also increases the cost. Summary of the Invention

[0006] The present invention provides a hybrid power system and a tractor, which not only enable the tractor to have different power drive modes, but also simplify the structure of the hybrid power system and save costs.

[0007] In a first aspect, the present invention provides a hybrid power system including an engine, a generator, a battery, a drive motor, a power output device, a rear axle, a brake, a first shifting device, and a power transmission module, wherein the power transmission module includes a planetary gear assembly, a first transmission assembly, a second transmission assembly, and a third transmission assembly;

[0008] An engine output shaft of the engine is connected to a power output shaft of the power output device;

[0009] The planetary gear assembly includes a sun gear, planetary gears, a planetary carrier and a ring gear. The output shaft of the drive motor is connected to the sun gear through the first transmission assembly. The sun gear is connected to the planetary gears, the planetary gears are connected to the ring gear, and the planetary carrier is connected to the planetary gears.

[0010] The engine output shaft is connected to the generator output shaft of the generator through a second transmission assembly;

[0011] The brake is provided on the ring gear, and the first shifting device is connected to the engine output shaft. When the first shifting device is in a first gear position, the engine output shaft and the ring gear are disconnected. When the first shifting device is in a second gear position, the engine output shaft is in transmission connection with the ring gear through the first shifting device.

[0012] The planet carrier is connected to the rear axle output shaft of the rear axle through the third transmission assembly;

[0013] The generator is connected to the battery so that the electrical energy generated by the generator is transmitted to the battery for storage;

[0014] The battery is also connected to the drive motor to supply power to the drive motor.

[0015] The hybrid power system provided by the present invention is provided with an engine, a generator, a first shifting device, a brake, and a planetary gear assembly. The engine and the ring gear are transmission-connected, the drive motor is transmission-connected to the sun gear, the rear axle is transmission-connected to the planetary carrier, and the engine and the generator are transmission-connected. The electric energy generated by the generator can be supplied to the drive motor, thereby enabling different operating modes of the hybrid power system. When the first shifting device is in the first gear, the brake is closed, and the engine is not operating, the hybrid power system is in pure electric mode. When the first shifting device is in the first gear, the brake is closed, and the engine is operating, the hybrid power system is in extended-range mode. When the first shifting device is in the second gear, the brake is open, and the engine is operating, the hybrid power system is in hybrid mode. Compared with existing hybrid tractors, the hybrid power system of the present invention not only can achieve different operating modes, but also eliminates the need for a transfer case or a motor for driving a power output device, thereby simplifying the system and saving costs.

[0016] In some possible implementation schemes, the first transmission assembly includes a first transmission gear, a duplex gear, and a duplex gear shaft;

[0017] The first transmission gear is connected to the output shaft of the drive motor, and the double gear is in transmission connection with the first transmission gear;

[0018] The duplex gear is connected to the sun gear via the duplex gear shaft.

[0019] In some possible implementations, the second transmission assembly includes a second transmission gear and a third transmission gear, the second transmission gear is connected to the engine output shaft, the third transmission gear is connected to the generator output shaft, and the second transmission gear and the third transmission gear are in transmission connection.

[0020] In some possible implementation schemes, the power transmission module further includes a fourth transmission gear, and the fourth transmission gear is transmission-connected to the ring gear;

[0021] The first shifting device is located between the fourth transmission gear and the second transmission gear. When the first shifting device is in the first gear position, the fourth transmission gear is disconnected from the generator output shaft. When the first shifting device is in the second gear position, the fourth transmission gear is connected to the generator output shaft.

[0022] In some possible implementation schemes, the brake is disposed between the fourth transmission gear and the ring gear.

[0023] In some possible implementations, a second shifting device is further included, wherein the second shifting device is connected to the rear axle output shaft;

[0024] The third transmission assembly includes a first rear axle transmission module and a second rear axle transmission module, the first rear axle transmission module and the second rear axle transmission module are respectively connected to the planetary carrier, the speed ratios of the first rear axle transmission module and the second rear axle transmission module are different, and the second shifting device is optionally connected to one of the first rear axle transmission module and the second rear axle transmission module.

[0025] In some possible implementation schemes, the first rear axle transmission module includes a first output driving gear and a first output driven gear, the planetary carrier is connected to the first output driving gear, the first output driven gear is used to connect to the second shifting device, and the first output driving gear is transmission-connected to the first output driven gear.

[0026] In some possible implementations, the second rear axle transmission module includes a second output driving gear and a second output driven gear, the planetary carrier is connected to the second output driving gear, the second output driven gear is used to be connected to the second shifting device, and the second output driving gear is transmission-connected to the second output driven gear.

[0027] In some possible implementation schemes, the second shifting device is a sliding sleeve or a synchronizer.

[0028] In some possible implementation schemes, the first shifting device is a sliding sleeve or a synchronizer.

[0029] In a second aspect, the present invention provides a tractor comprising a hybrid power system as described in any possible embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of the overall structure of a hybrid power system according to an embodiment of the present invention;

[0031] FIG2 is a schematic diagram of the working state of the hybrid power system in the pure electric mode according to an embodiment of the present invention;

[0032] FIG3 is a schematic diagram of the working state of the hybrid power system in the extended range mode according to an embodiment of the present invention;

[0033] FIG4 is a schematic diagram of the working state of the hybrid power system in the hybrid mode according to an embodiment of the present invention.

[0034] 1-Engine; 11-Engine output shaft; 2-Generator; 21-Generator output shaft; 3-Battery; 4-Drive motor; 41-Drive motor output shaft; 5-Power take-off device; 51-Power take-off shaft; 6-Rear axle; 61-Rear axle output shaft; 7-Brake; 8-First shifting device; 9-Second shifting device; 100-Planetary gear assembly; 110-Sun gear; 120-Planetary gear; 130-Planet carrier; 140-Ring gear; 200-First transmission assembly ;210-first transmission gear;220-dual gear;230-dual gear shaft;300-second transmission assembly;310-second transmission gear;320 third transmission gear;400-third transmission assembly;410-first rear axle transmission module;411-first output driving gear;412-first output driven gear;420-second rear axle transmission module;421-second output driving gear;422-second output driven gear;500-fourth transmission gear. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] 1 , the hybrid power system in an embodiment of the present invention may include an engine 1, a generator 2, a battery 3, a drive motor 4, a power output device 5, a rear axle 6, a brake 7, a first shifting device 8, a second shifting device 9 and a power transmission module, wherein the power transmission module may include a planetary gear assembly 100, a first transmission assembly 200, a second transmission assembly 300 and a third transmission assembly 400.

[0037] The drive motor output shaft 41 of the drive motor 4 is in transmission connection with the planetary gear assembly 100 via the first transmission assembly 200. Specifically, the first transmission assembly 200 includes a first transmission gear 210, a duplex gear 220, and a duplex gear shaft 230. The planetary gear assembly 100 includes a sun gear 110, planetary gears 120, a planetary carrier 130, and a ring gear 140. The first transmission gear 210 is connected to the drive motor output shaft 41, and the first transmission gear 210 is in transmission connection with the duplex gear 220. The duplex gear 220 is connected to the sun gear 110 via the duplex gear shaft 230. The sun gear 110 is in transmission connection with the planetary gears 120, the planetary gears 120 are in transmission connection with the ring gear 140, and the planetary carrier 130 is connected to the planetary gears 120. That is, the output power of the drive motor output shaft 41 can pass through the first transmission gear 210 , the dual gear 220 , the dual gear shaft 230 , the sun gear 110 and the planetary gear 120 in sequence, and then be output by the planetary carrier 130 .

[0038] The engine output shaft 11 of the engine 1 is connected to the generator output shaft 21 of the generator 2 via a second transmission assembly 300. Specifically, the second transmission assembly 300 includes a second transmission gear 310 and a third transmission gear 320. The second transmission gear 310 is connected to the engine output shaft 11, and the third transmission gear 320 is connected to the generator output shaft 21. The second and third transmission gears 310 and 320 are in a transmission connection with each other. When the engine output shaft 11 outputs power, the power is sequentially transmitted to the generator output shaft 21 via the second and third transmission gears 310 and 320, thereby driving the generator 2 to generate electricity.

[0039] The power transmission module also includes a fourth transmission gear 500. The first shifting device 8 is disposed between the second transmission gear 310 and the fourth transmission gear 500, and the first shifting device 8 is connected to the generator output shaft 21. The first shifting device 8 has two gears. When the first shifting device 8 is in the first gear, the first shifting device 8 is disconnected from the fourth transmission gear 500, meaning that the output power of the generator output shaft 21 cannot be transmitted to the fourth transmission gear 500. When the first shifting device 8 is in the second gear, the first shifting device 8 is connected to the fourth transmission gear 500, thereby connecting the fourth transmission gear 500 to the generator output shaft 21, and the output power of the generator output shaft 21 can be transmitted through the fourth transmission gear 500.

[0040] The brake 7 is mounted on the ring gear 140, and the fourth transmission gear 500 is in transmission connection with the ring gear 140. When the brake 7 is closed, the ring gear 140 cannot rotate, and no power is transmitted between the ring gear 140 and the planetary gears 120. When the brake 7 is released, the ring gear 140 can rotate, and power can be transmitted between the ring gear 140 and the planetary gears 120. After the ring gear 140 transmits power to the planetary gears 120, the planetary gears 120 transmit the power to the planetary carrier 130, and finally the planetary carrier 130 outputs the power. In other words, the planetary gear assembly 100 in this embodiment has two power transmission paths, one of which is from the sun gear 110 to the planetary carrier 130, and the other is from the ring gear 140 to the planetary carrier 130. The power transmitted by these two power transmission paths can be coupled.

[0041] Continuing with Figure 1 , the generator 2 is connected to the battery 3, which is in turn connected to the drive motor 4. After the engine 1 starts generating electricity, the generator 2 can transfer the generated electricity to the battery 3 for storage. The stored electricity in the battery 3 can then be supplied to the drive motor 4, causing the drive motor output shaft 41 of the drive motor 4 to start operating.

[0042] The planet carrier 130 is connected to the rear axle output shaft 61 of the rear axle 6 via the third transmission assembly 400. Specifically, the third transmission assembly 400 includes a first rear axle transmission module 410 and a second rear axle transmission module 420. The first rear axle transmission module 410 includes a first output driving gear 411 and a first output driven gear 412, and the second rear axle transmission module 420 includes a second output driving gear 421 and a second output driven gear 422. The first output driving gear 411 and the second output driving gear 421 are respectively connected to the planet carrier 130, the first output driven gear 412 is in transmission connection with the first output driving gear 411, and the second output driven gear 422 is in transmission connection with the second output driving gear 421.

[0043] The second shifting device 9 is connected to the rear axle output shaft 61, and is disposed between the first output driven gear 412 and the second output driven gear 422. The second shifting device 9 can selectively be connected to one of the first output driven gear 412 and the second output driven gear 422. The first output driven gear 412 and the second output driven gear 422 have different speed ratios. When the second shifting device 9 is connected to the first output driven gear 412 or the second output driven gear 422, the travel speed of the rear axle 6 changes to meet different usage requirements. For example, when the second shifting device 9 is in the first gear position, the second shifting device 9 is connected to the first output driven gear 412. At this time, the rear axle output shaft 61 is driven by the first output driving gear 411 and the first output driven gear 412. When the second shifting device 9 is in the second gear position, the second shifting device 9 is connected to the second output driven gear 422 . At this time, the rear axle output shaft 61 is driven by the second output driving gear 421 and the second output driven gear 422 .

[0044] The engine output shaft 11 of the engine 1 is also connected to the power output shaft 51 of the power output device 5. That is, when the engine 1 is running, it can drive the power output device 5 to output power.

[0045] In addition, the first shifting device 8 in this embodiment may be, for example, a sliding sleeve or a synchronizer, and similarly, the second shifting device 9 may also be, for example, a sliding sleeve or a synchronizer. Alternatively, in other embodiments, the first shifting device 8 may be a dry clutch, a wet clutch, an electromagnetic clutch, etc., and the second shifting device 9 may also be a dry clutch, a wet clutch, an electromagnetic clutch, etc.

[0046] Based on the same inventive concept, an embodiment of the present invention may further provide a tractor, which includes the hybrid power system as described in the above embodiment.

[0047] Based on the specific structure of the hybrid system in this embodiment, the hybrid system in this embodiment can have a pure electric mode, an extended-range mode, and a hybrid mode. The following describes each of these modes in detail in conjunction with Table 1. It should be noted that the dashed arrows in Figures 2 to 4 can be understood as the direction of output power or electrical energy transmission.

[0048] Table 1:

[0049] In conjunction with Table 1 and Figure 2, when the hybrid system in this embodiment is in pure electric mode, the brake 7 is closed, the first shift device 8 is in the left position (first gear), and the ring gear 140 does not rotate. At the same time, the engine 1 is not working, and at this time, the power output device 5 does not perform external work. The battery 3 supplies power to the drive motor 4 to rotate the drive motor output shaft 41. The power of the drive motor output shaft 41 is transmitted to the third transmission assembly 400 after passing through the first transmission gear 210, the double gear 220, the double gear shaft 230, the sun gear 110, the planetary gear 120 and the planetary carrier 130, and finally transmitted to the rear axle 6 by the third rotating assembly, thereby driving the rear axle 6 to move.

[0050] In pure electric mode, when the second shifting device 9 is in the first gear, the second shifting device 9 engages to the left and is connected to the first output driven gear 412. At this time, the rear axle 6 runs at the speed of the first gear. When the second shifting device 9 is in the second gear, the second shifting device 9 engages to the right and is connected to the second output driven gear 422. At this time, the rear axle 6 runs at the speed of the second gear.

[0051] In conjunction with Table 1 and Figure 3, when the hybrid system in this embodiment is in extended-range mode, brake 7 is closed, first shifter 8 is in the left position (first gear), and ring gear 140 does not rotate. Engine 1 is operating. At this time, power from engine output shaft 11 is transmitted to power output shaft 51, driving power output shaft 51 to perform external work. Simultaneously, power from engine output shaft 11 is transmitted via second transmission assembly 300 to generator output shaft 21, driving generator 2 to generate electricity. The generated electricity is then transmitted to battery 3, which in turn transmits it to drive motor 4, activating drive motor 4. Power from drive motor output shaft 41 is then transmitted sequentially through first transmission gear 210, duplex gear 220, duplex gear shaft 230, sun gear 110, planetary gears 120, and planetary carrier 130, then to first transmission gear 210, sun gear 110, and finally to third transmission assembly 400. Finally, power is transmitted via the third rotating assembly to rear axle 6, driving rear axle 6. In this mode, the hybrid system can be used for plowing and rotary tillage operations in a tractor.

[0052] In the extended-range mode, when the second shifting device 9 is in the first gear position, the second shifting device 9 engages to the left and is connected to the first output driven gear 412. At this time, the rear axle 6 travels at the speed of the first gear. When the second shifting device 9 is in the second gear position, the second shifting device 9 engages to the right and is connected to the second output driven gear 422. At this time, the rear axle 6 travels at the speed of the second gear.

[0053] In conjunction with Table 1 and Figure 4 , when the hybrid system of this embodiment is in hybrid mode, brake 7 is disengaged, first shifter 8 is in right gear (second gear), and ring gear 140 is rotatable. Engine 1 is operating, and power from engine output shaft 11 is transmitted to power output shaft 51, thereby driving power output shaft 51 to perform external work. Power from engine output shaft 11 is also transmitted to third transmission assembly 400, sequentially through fourth transmission gear 500, ring gear 140, planetary gears 120, and planetary carrier 130. Simultaneously, battery 3 supplies power to drive motor 4, enabling operation. Power from drive motor output shaft 41 is transmitted sequentially through first transmission gear 210, duplex gear 220, duplex gear shaft 230, sun gear 110, planetary gears 120, and planetary carrier 130, and then to first transmission gear 210 and sun gear 110, then to third transmission assembly 400. During this process, the output power of the engine 1 and the output power of the drive motor 4 are coupled through the planetary gear assembly 100 and transmitted to the third transmission assembly 400, which in turn drives the rear axle 6 for movement. In this mode, the hybrid system can be used in both plowing mode and rotary tillage mode.

[0054] It should be noted that in hybrid mode, when the engine 1 is working, it can also drive the generator 2 to generate electricity, so that the electricity generated by the generator 2 is transmitted to the battery 3 to ensure that the battery 3 can supply sufficient electricity to the drive motor 4, so that the drive motor 4 can continue to work.

[0055] In hybrid mode, when the second shifting device 9 is in the first gear position, the second shifting device 9 engages to the left and is connected to the first output driven gear 412. At this time, the rear axle 6 runs at the speed of the first gear. When the second shifting device 9 is in the second gear position, the second shifting device 9 engages to the right and is connected to the second output driven gear 422. At this time, the rear axle 6 runs at the speed of the second gear.

[0056] It's worth noting that the hybrid system in this embodiment incorporates a brake 7 on the ring gear 140 and a first shifting device 8, which can be used to change the direction of power flow, thereby enabling switching between extended-range and hybrid modes. The hybrid system in this embodiment can also vary the speed of the rear axle 6 by changing the speed of the drive motor 4, thereby achieving infinitely variable speeds. By varying the gear position of the second shifting device 9, varying torque and speed requirements can be met.

[0057] In hybrid mode, the hybrid system of this embodiment couples the output power of the engine 1 and the output power of the drive motor 4, thereby improving the overall vehicle's dynamic performance. Due to the use of the planetary gear assembly 100, in hybrid mode, the rotational speed of the engine 1 and the speed of the rear axle 6 are decoupled, allowing the engine 1 to consistently operate in a high-efficiency range and reducing fuel consumption. Furthermore, in hybrid mode, a portion of the power for the rear axle 6 is transmitted via the ring gear 140. This power transmission process avoids the conversion of mechanical energy to electrical energy and back to mechanical energy, thereby improving transmission efficiency.

[0058] It should be noted that, in this embodiment, the second shifting device 9 includes two gears for illustration only. In actual application, more gears may be added according to actual needs, and this embodiment does not limit this.

[0059] Compared with existing hybrid tractors, the hybrid system in this embodiment reduces the transfer case or the motor used to drive the power drive device to perform external work, which not only simplifies the system but also helps save costs and installation space.

[0060] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A hybrid power system, characterized in that: The vehicle comprises an engine, a generator, a battery, a drive motor, a power output device, a rear axle, a brake, a first shifting device and a power transmission module, wherein the power transmission module comprises a planetary gear assembly, a first transmission assembly, a second transmission assembly and a third transmission assembly; An engine output shaft of the engine is connected to a power output shaft of the power output device; The planetary gear assembly includes a sun gear, planetary gears, a planetary carrier and a ring gear. The output shaft of the drive motor is connected to the sun gear through the first transmission assembly. The sun gear is connected to the planetary gears, the planetary gears are connected to the ring gear, and the planetary carrier is connected to the planetary gears. The engine output shaft is connected to the generator output shaft of the generator through a second transmission assembly; The brake is provided on the ring gear, and the first shifting device is connected to the engine output shaft. When the first shifting device is in a first gear position, the engine output shaft and the ring gear are disconnected. When the first shifting device is in a second gear position, the engine output shaft is in transmission connection with the ring gear through the first shifting device. The planet carrier is connected to the rear axle output shaft of the rear axle through the third transmission assembly; The generator is connected to the battery so that the electrical energy generated by the generator is transmitted to the battery for storage; The battery is also connected to the drive motor to supply power to the drive motor.

2. The hybrid power system according to claim 1, characterized in that: The first transmission assembly includes a first transmission gear, a duplex gear and a duplex gear shaft; The first transmission gear is connected to the output shaft of the drive motor, and the double gear is in transmission connection with the first transmission gear; The duplex gear is connected to the sun gear via the duplex gear shaft.

3. The hybrid power system according to claim 1 or 2, characterized in that: The second transmission assembly includes a second transmission gear and a third transmission gear. The second transmission gear is connected to the engine output shaft, and the third transmission gear is connected to the generator output shaft. The second transmission gear and the third transmission gear are in transmission connection.

4. The hybrid power system according to claim 3, characterized in that: The power transmission module further includes a fourth transmission gear, the fourth transmission gear being transmission-connected to the ring gear; The first shifting device is located between the fourth transmission gear and the second transmission gear. When the first shifting device is in the first gear position, the fourth transmission gear is disconnected from the generator output shaft. When the first shifting device is in the second gear position, the fourth transmission gear is connected to the generator output shaft.

5. The hybrid power system according to any one of claims 1 to 4, characterized in that: Also included is a second shifting device connected to the rear axle output shaft; The third transmission assembly includes a first rear axle transmission module and a second rear axle transmission module, the first rear axle transmission module and the second rear axle transmission module are respectively connected to the planetary carrier, the speed ratios of the first rear axle transmission module and the second rear axle transmission module are different, and the second shifting device is optionally connected to one of the first rear axle transmission module and the second rear axle transmission module.

6. The hybrid power system according to claim 5, characterized in that: The first rear axle transmission module includes a first output driving gear and a first output driven gear. The planetary carrier is connected to the first output driving gear. The first output driven gear is used to be connected to the second shifting device, and the first output driving gear is transmission-connected to the first output driven gear.

7. The hybrid power system according to claim 5 or 6, characterized in that: The second rear axle transmission module includes a second output driving gear and a second output driven gear. The planet carrier is connected to the second output driving gear. The second output driven gear is used to be connected to the second shifting device, and the second output driving gear is transmission-connected to the second output driven gear.

8. The hybrid power system according to any one of claims 5 to 7, characterized in that: The second shifting device is a sliding sleeve or a synchronizer.

9. The hybrid power system according to any one of claims 1 to 8, characterized in that: The first shifting device is a sliding sleeve or a synchronizer.

10. A tractor, characterized in that: The hybrid power system comprises the hybrid power system according to any one of claims 1 to 9.

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