A transmission system and electric tractor

Abstract

The application discloses a transmission system and an electric tractor, which comprises a first input shaft, a first output shaft in transmission connection with the first input shaft, a second output shaft provided with a first shift sleeve, the first shift sleeve being used for realizing power interruption between the second output shaft and the first input shaft or transmission according to a set first speed ratio, the second output shaft being capable of having a constant output rotating speed during work, a third output shaft in transmission connection with the first input shaft, and a second shift sleeve provided on the third output shaft, the second shift sleeve being used for realizing power interruption of the third output shaft or transmission according to a set second speed ratio. The application can reduce the number of gear positions of the transmission system and meet the power demand of the tractor under different working conditions.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery technology, specifically to a transmission system and an electric tractor. Background Technology

[0002] The transmission system is an important component of electric tractor loaders. Its main task is to drive the tractor or other agricultural machinery through the transmission of power from the drive motor via meshing gears, and through components such as the drive shaft, axle, and tires.

[0003] Tractors primarily operate in fieldwork and off-road environments, facing diverse and harsh conditions. In addition to traction power, tractors require PTO (Power Transfer Towing) power output to drive implements, as well as hydraulic pump power output. These three power output requirements can vary, sometimes requiring a single power condition, and sometimes all three simultaneously, making the power output demands complex. When tractor operation demands simultaneous traction power and PTO output, the fundamental requirement is that the target vehicle speed matches the PTO-driven implement speed to efficiently and effectively complete tasks like rotary tillage. Traditional fuel-powered tractors typically require a constant engine speed during continuous operation to achieve a stable PTO output. To cope with varying operating conditions, the transmission needs to constantly shift gears to maintain a stable target speed while meeting changing traction power requirements. Therefore, traditional fuel-powered tractor transmissions are equipped with many gears, some even having over 40 forward / reverse gears. These transmissions are complex in structure, difficult to manufacture, require high quality control, and are costly. The frequent gear shifts during operation negatively impact work quality and efficiency. Some single-motor driven electric tractors on the market, when simultaneously requiring traction output, PTO output, and hydraulic drive output, either cannot operate in their high-efficiency range while prioritizing a constant PTO speed output, or they cannot independently adjust the speed to match the vehicle speed with the PTO speed. This results in poor performance in tasks such as tilling, for example, due to excessively large clods of soil or low work efficiency. There are also some dual-motor electric tractors on the market, but due to unreasonable transmission mechanism configurations, they cannot achieve a wide range of working modes and cannot meet the complex and diverse needs of tractor field operations.

[0004] Traditional tractor transmissions often use a dozen or even more than 40 gears, which are complex in structure, with a large number of gears, shafts, and bearings, and many meshing gear pairs during transmission. This type of structure not only has a large number of parts and high cost, but also low transmission efficiency.

[0005] In addition, many traditional tractor transmissions and electric tractors on the market today still use manual shifting mechanisms, which result in low operating efficiency and high labor intensity for drivers.

[0006] How to reduce the number of gears in electric tractors while meeting the power requirements of tractors under different working conditions is one of the important problems that urgently need to be solved in this field. Summary of the Invention

[0007] The purpose of this invention is to provide a transmission system and an electric tractor to overcome the shortcomings of the prior art. It can reduce the number of gears in the transmission system and meet the power requirements of the tractor under different working conditions.

[0008] This invention provides a transmission system, comprising,

[0009] First input axis;

[0010] The first output shaft is connected to the first input shaft via a drive.

[0011] A second output shaft is provided with a first shift sleeve; the first shift sleeve is used to realize the power interruption between the second output shaft and the first input shaft, or to transmit according to a set first speed ratio; the second output shaft can have a constant output speed when working;

[0012] The third output shaft is connected to the first input shaft for transmission, and the third output shaft is provided with a second shift sleeve; the second shift sleeve is used to realize the power interruption of the third output shaft, or to transmit according to a set second speed ratio.

[0013] The transmission system described above, optionally, also includes a second input shaft, an intermediate shaft, and a fourth output shaft;

[0014] A planetary gear pair is mounted on the second input shaft; the second output shaft is connected to the first output shaft and the intermediate shaft respectively via the planetary gear pair.

[0015] A third shift sleeve is installed on the second input shaft. The third shift sleeve is used to realize the engagement or disengagement between the sun gear of the planetary gear pair and the planet carrier of the planetary gear pair.

[0016] The fourth output shaft is provided with a fourth shift sleeve, which is used to interrupt the power between the fourth output shaft and the intermediate shaft, or to transmit power according to a set third speed ratio.

[0017] In the transmission system described above, optionally, the second input shaft is fixedly connected to the sun gear of the planetary gear pair; the first output shaft is drivenly connected to the ring gear of the planetary gear pair; and the intermediate shaft is drivenly connected to the planet carrier of the planetary gear pair.

[0018] In the transmission system described above, optionally, the reversal of the third and fourth output shafts is achieved by the reversal of the first and / or second output shafts.

[0019] In the transmission system described above, optionally, when the third output shaft has power output and the fourth output shaft does not have power output: the transmission system has at least four gears;

[0020] When both the third output shaft and the fourth output shaft have power output, there are at least four gear positions.

[0021] In the transmission system described above, optionally, the transmission system, in its operating state, can simultaneously have the following power transmission paths:

[0022] The first input shaft transmits power to the first output shaft;

[0023] The first input shaft transmits power to the first output shaft, and then to the second output shaft via the first output shaft;

[0024] The first input shaft transmits power to the first output shaft, and then to the second input shaft via the first output shaft, thereby achieving power coupling with the second input shaft;

[0025] The second input shaft is powered by the first output shaft through the planetary gear pair, and outputs to the intermediate shaft, and then outputs to the third output shaft and the fourth output shaft respectively.

[0026] In the transmission system described above, optionally, the first shift sleeve, the second shift sleeve, and the third shift sleeve have the same structure.

[0027] In the transmission system described above, optionally, the centerline of the first input shaft and the centerline of the second output shaft are on the same straight line;

[0028] The centerline of the second input shaft and the centerline of the third output shaft are on the same straight line;

[0029] The first input shaft, the first output shaft, the second input shaft, the intermediate shaft, and the fourth output shaft are arranged in parallel.

[0030] In the transmission system described above, optionally, the switching of the first shift sleeve, the second shift sleeve, and the third shift sleeve is driven by electricity, hydraulic pressure, or pneumatic pressure.

[0031] The present invention also proposes an electric tractor, comprising a first motor, a second motor, a hydraulic pump, a rear axle drive shaft, a front axle drive shaft, and implements, wherein it further comprises a transmission system as described in any of the preceding claims;

[0032] The first motor is connected to the first input shaft, and the second motor is connected to the second input shaft; the hydraulic pump is connected to the first output shaft, the rear axle drive shaft is connected to the third output shaft, and the front axle drive shaft is connected to the fourth output shaft.

[0033] Compared with the prior art, the transmission system proposed in this invention provides at least three output shafts to meet the power requirements of tractors for multiple output conditions.

[0034] This invention, by setting up a dual-motor structure, allows the power of the first motor and the second motor to be coupled through a planetary gear pair, enabling direct drive and speed adjustment. Matched with an optimized sliding sleeve shifting mechanism, it can cope with multiple power output conditions while maintaining high motor operating efficiency, achieving high system efficiency, reducing energy consumption, and increasing continuous operation time.

[0035] This invention utilizes a dual-motor drive system with multiple shift sleeves to fully leverage the motor's wide speed range and efficient operating zone. It optimizes the speed ratio configuration, reduces the number of gears in the transmission, and meets the requirements of multiple working conditions and high-efficiency operation of the tractor. At the same time, it minimizes gear shifting during the operation of the electric tractor, thereby reducing shifting actions and improving the overall operating efficiency of the machine.

[0036] In this invention, the automatic gear shifting function controlled by the TCU can more rationally control the number of gear shifts and the timing of gear shifts, so as to ensure that the motor operates in the high-efficiency range and at the same time reduce the driver's labor intensity. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the transmission system proposed in this invention;

[0038] Figure 2 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under four-wheel drive and first gear.

[0039] Figure 3 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under four-wheel drive and second gear;

[0040] Figure 4 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under four-wheel drive and three-speed conditions;

[0041] Figure 5 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under four-wheel drive and four-speed conditions;

[0042] Figure 6 This is a schematic diagram of the power transmission of the transmission system proposed in this invention in second-wheel drive and first gear;

[0043] Figure 7 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under two-wheel drive and two-gear conditions;

[0044] Figure 8 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under two-wheel drive and three-speed conditions;

[0045] Figure 9 This is a schematic diagram of the power transmission of the transmission system proposed in this invention under two-wheel drive and four-speed conditions;

[0046] Figure 10 This is a schematic diagram of power transmission of the transmission system proposed in this invention under driving operation conditions;

[0047] Figure 11 This is a schematic diagram of the planetary gear pair proposed in this invention;

[0048] Figure 12 This is a schematic diagram of the structure of the first shift sleeve proposed in this invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1 - First input shaft, 2 - First output shaft, 3 - Second output shaft, 4 - First shift sleeve, 5 - Third output shaft, 6 - Second shift sleeve, 7 - Second input shaft, 8 - Intermediate shaft, 9 - Fourth output shaft, 10 - Planetary gear pair, 11 - Third shift sleeve, 12 - Fourth shift sleeve, 13 - First motor, 14 - Second motor;

[0051] 41 - Sliding sleeve body, 42 - Snap ring, 43 - Spline pad, 44 - Adjusting pad;

[0052] 101 - Sun gear, 102 - Planet carrier, 103 - Gear ring;

[0053] Z1 - First gear, Z2 - Second gear, Z3 - Third gear, Z4 - Fourth gear, Z5 - Fifth gear, Z6 - Sixth gear, Z7 - Seventh gear, Z8 - Eighth gear, Z9 - Ninth gear, Z10 - Tenth gear, Z11 - Eleventh gear, Z12 - Twelfth gear, Z13 - Thirteenth gear, Z14 - Fourteenth gear, Z15 - Fifteenth gear, Z16 - Sixteenth gear. Detailed Implementation

[0054] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0055] To address the problems raised in the background section, research on the transmissions of traditional fuel-powered tractors and electric tractors revealed the following: Traditional fuel-powered tractors have too many gears, resulting in complex transmission structures, high manufacturing difficulty, stringent quality control requirements, and high costs; the frequent gear shifts during operation negatively impact work quality and efficiency. Existing electric tractor transmissions typically have too few gears, sometimes only two, or are single-motor driven, failing to guarantee efficient motor operation and overall machine efficiency; or they may be dual-motor driven, but lack the flexibility to switch between coupled and direct drive, affecting motor operating efficiency and overall machine efficiency. To address these issues, the following solutions are proposed.

[0056] Example 1

[0057] Please refer to Figure 1 This embodiment proposes a transmission system, which includes at least a first input shaft 1, a first output shaft 2, a second output shaft 3, and a third output shaft 5. The first input shaft 1 is used for transmission connection with a first motor 13 on a tractor equipped with this transmission system. The first output shaft 2 is used to drive a hydraulic pump on the tractor equipped with this transmission system to provide power to the tractor's hydraulic system. The second output shaft 3 is used for transmission connection with agricultural implements on the tractor equipped with this transmission system to provide power to the implements. The third output shaft 5 is used for transmission connection with the drive shaft of the tractor equipped with this transmission system to drive the tractor. Specifically, the first output shaft 2 is transmission connected to the first input shaft 1. In a specific implementation, a first gear Z1 is mounted on the first input shaft 1, and a second gear Z2, a fourth gear Z4, and a sixth gear Z6 are mounted on the first output shaft 2. The first gear Z1 is keyed to the first input shaft 1, and the second gear Z2, the fourth gear Z4, and the sixth gear Z6 are all keyed to the first output shaft 2. The first gear Z1 meshes with the second gear Z2.

[0058] A first shift sleeve 4 is provided on the second output shaft 3. A third gear Z3 and a fifth gear Z5 are fitted on the second output shaft 3, and the first shift sleeve 4 is located between the third gear Z3 and the fifth gear Z5. The first shift sleeve 4 has three position states:

[0059] In the first position state, the first shift sleeve 4 meshes with the third gear Z3, there is power transmission between the second output shaft 3 and the third gear Z3, and there is no power transmission between the second output shaft 3 and the fifth gear Z5.

[0060] In the second position state, the first shift sleeve 4 is neither engaged with the third gear Z3 nor with the fifth gear Z5, and there is no power transmission between the second output shaft 3 and the third gear Z3, nor between the second output shaft 3 and the fifth gear Z5.

[0061] In the third position, the first shift sleeve 4 meshes with the fifth gear Z5, there is no power transmission between the second output shaft 3 and the third gear Z3, and there is power transmission between the second output shaft 3 and the fifth gear Z5.

[0062] The first shift sleeve 4 is used to interrupt power between the second output shaft 3 and the first input shaft 1, or to transmit power according to a set first speed ratio. Specifically, the first speed ratio has two values: the speed ratio resulting from the transmission between the third gear Z3 and the fourth gear Z4, and the speed ratio resulting from the transmission between the fifth gear Z5 and the sixth gear Z6. The second output shaft 3 can maintain a constant output speed during operation. In practice, the constant speed of the second output shaft 3 can be controlled by the first motor 13 connected to the first input shaft 1. In practical applications, it can be stabilized at approximately 540 rpm or 1000 rpm. By controlling the second output shaft 3 to be constant, the power requirements of agricultural implements during actual operation can be met.

[0063] The third output shaft 5 is connected to the first input shaft 1. A second shift sleeve 6 is provided on the third output shaft 5. A ninth gear Z9 and an eleventh gear Z11 are fitted on the third output shaft 5. The second shift sleeve 6 is located between the ninth gear Z9 and the eleventh gear Z11, and can mesh with either the ninth gear Z9 or the eleventh gear Z11. Specifically, the second shift sleeve 6 has three position states:

[0064] In the first position state, the second shift sleeve 6 meshes with the ninth gear Z9, there is power transmission between the third output shaft 5 and the ninth gear Z9, and there is no power transmission between the third output shaft 5 and the eleventh gear Z11.

[0065] In the second position state, the second shift sleeve 6 is neither engaged with the ninth gear Z9 nor with the eleventh gear Z11, and there is no power transmission between the third output shaft 5 and the ninth gear Z9, nor between the third output shaft 5 and the eleventh gear Z11.

[0066] In the third position, the second shift sleeve 6 meshes with the eleventh gear Z11, there is no power transmission between the third output shaft 5 and the ninth gear Z9, and there is power transmission between the third output shaft 5 and the eleventh gear Z11.

[0067] Among them, the ninth gear Z9 and the eleventh gear Z11 can both have a power transmission relationship with the first input shaft 1.

[0068] The second shift sleeve 6 is used to interrupt the power of the third output shaft 5, or to transmit power according to a set second speed ratio. Specifically, there can be two values ​​for the second speed ratio: the speed ratio when the ninth gear Z9 is involved in the transmission and the speed ratio generated when the eleventh gear Z11 is involved in the transmission.

[0069] Based on the above, the transmission system proposed in this invention, by setting at least three output shafts, can meet the power requirements of tractors in multiple operating conditions. Especially for implement drive, it can ensure a constant rotational speed.

[0070] While the above solutions can largely meet the requirements of the transmission system for tractors, they cannot meet the demands of high-power, long-term operation of tractors, especially for electric tractors. Specifically, under normal circumstances, a single motor can only provide high-power continuous drive for about one hour, which is insufficient to meet the long-term driving and operation needs of tractors.

[0071] Therefore, this embodiment is further improved by including a second input shaft 7, an intermediate shaft 8, and a fourth output shaft 9. The second input shaft 7 and the first input shaft 1 are respectively connected to the two motors of the tractor equipped with this transmission system. The intermediate shaft 8 is used to realize power transmission within the transmission system. Specifically, the intermediate shaft 8 is equipped with an eighth gear Z8, a twelfth gear Z12, a thirteenth gear Z13, and a fifteenth gear Z15, and all of these gears are keyed to the intermediate shaft 8. The tenth gear Z10 meshes with the ninth gear Z9, and the twelfth gear Z12 meshes with the eleventh gear Z11.

[0072] A planetary gear pair 10 is mounted on the second input shaft 7; please refer to... Figure 11 The second output shaft 3 is connected to the first output shaft 2 and the intermediate shaft 8 respectively through the planetary gear pair 10.

[0073] A third shift sleeve 11 is mounted on the second input shaft 7. The third shift sleeve 11 is used to engage or disengage the sun gear 101 of the planetary gear pair 10 with the planet carrier 102 of the planetary gear pair 10. In a specific implementation, the planet carrier 102 is connected to the seventh gear Z7, and the seventh gear Z7 meshes with the eighth gear Z8.

[0074] The fourth output shaft 9 is provided with a fourth shift sleeve 12, which is used to interrupt power between the fourth output shaft 9 and the intermediate shaft 8, or to transmit power according to a set third speed ratio. Specifically, the fourteenth gear Z14 and the sixteenth gear Z16 are sleeved on the fourth output shaft 9. The fourteenth gear Z14 meshes with the thirteenth gear Z13, and the sixteenth gear Z16 meshes with the fifteenth gear Z15. The fourth output shaft 9 is used for transmission connection with the front axle drive shaft of an electric tractor equipped with this transmission system.

[0075] This embodiment, through the above structure, can achieve optimal power and torque transmission of the electric tractor, meet the tractor's requirements for traction, speed and efficiency, and reduce the number of gears in the transmission, the number of construction parts, and the reliability.

[0076] This embodiment combines different working states of the shift sleeve, and can be driven by a single motor or by dual motor coupling, depending on the working conditions. This makes it more likely that the motor will operate in the high-efficiency range, thereby improving the overall efficiency and reducing energy consumption.

[0077] Specifically, in order to achieve dynamic coupling between the first input shaft 1 and the second input shaft 7, this embodiment also makes the following improvements, please refer to... Figure 11 The second input shaft 7 is fixedly connected to the sun gear 101 of the planetary gear pair 10; the first output shaft 2 is drivenly connected to the gear ring 103 of the planetary gear pair 10. In practice, the outer circumference of the gear ring 103 is provided with teeth for meshing with the fourth gear Z4; the intermediate shaft 8 is drivenly connected to the planet carrier 102 of the planetary gear pair 10.

[0078] This embodiment can be driven by power coupling or by disconnecting the coupling to achieve direct drive. The driving mode is flexible and diverse, which can flexibly solve the contradiction between the tractor's high-power continuous driving operation for many hours and the motor's high-power continuous driving characteristic for only about one hour. The two motors can alternately output high power according to the operation requirements to meet the tractor's continuous high-power output operation requirements.

[0079] The optimized sliding sleeve shifting mechanism configuration in this embodiment enables flexible switching between four-wheel drive and two-wheel drive according to operating conditions; at the same time, it can flexibly switch between single power output, dual power output, and triple power output.

[0080] Furthermore, to simplify the mechanical structure, the transmission system proposed in this invention does not have a reverse gear. When the electric tractor is working, the reverse function is achieved by reversing the first motor 13 and the second motor 14, reducing the time for shifting to reverse gear. It also allows for pre-shifting to reverse gear, reducing wasted time, improving machine efficiency, and lowering energy consumption. Simultaneously, the absence of a reverse gear in the transmission reduces the number of parts and increases product reliability. Specifically, the reversal of the third output shaft 5 and the fourth output shaft 9 is achieved by reversing the first output shaft 2 and / or the second output shaft 3.

[0081] With the above structure, in this embodiment, when the third output shaft 5 has power output and the fourth output shaft 9 does not have power output: the transmission system has at least four gears. That is, the electric tractor equipped with this transmission system has at least four gears in two-wheel drive mode.

[0082] When both the third output shaft 5 and the fourth output shaft 9 have power output, there are at least four gear positions. That is, when the electric tractor equipped with this transmission system is in four-wheel drive mode, it has at least four gear positions.

[0083] That is, the main gears available when this transmission system is installed on an electric tractor are shown in Table 1.

[0084] Table 1 Main Units

[0085]

[0086] Referring to Table 1, please refer to... Figure 2 In four-wheel drive and first gear mode, power is input from the first input shaft 1, transmitted to the intermediate shaft 8 after passing through the planetary gear pair 10, and then transmitted to the third output shaft 5 through the twelfth gear Z12 and the eleventh gear Z11. At the same time, the power on the intermediate shaft 8 is transmitted to the fourth output shaft 9 through the fifteenth gear Z15 and the sixteenth gear Z16.

[0087] Referring to Table 1, please refer to... Figure 3 In four-wheel drive, second gear, power is input from the first input shaft 1, transmitted to the intermediate shaft 8 via the planetary gear pair 10, and then transmitted to the third output shaft 5 via the tenth gear Z10 and the ninth gear Z9. At the same time, the power on the intermediate shaft 8 is transmitted to the fourth output shaft 9 via the thirteenth gear Z13 and the fourteenth gear Z14.

[0088] Referring to Table 1, please refer to... Figure 4In four-wheel drive and three-speed mode, power is input from the first input shaft 1 and the second input shaft 7, coupled through the planetary gear pair 10, and then transmitted to the intermediate shaft 8. It is then transmitted to the third output shaft 5 through the twelfth gear Z12 and the eleventh gear Z11. At the same time, the power on the intermediate shaft 8 is transmitted to the fourth output shaft 9 through the fifteenth gear Z15 and the sixteenth gear Z16.

[0089] Referring to Table 1, please refer to... Figure 5 In four-wheel drive and four-speed mode, power is input from the first input shaft 1 and the second input shaft 7, coupled through the planetary gear pair 10, and then transmitted to the intermediate shaft 8. It is then transmitted to the third output shaft 5 through the tenth gear Z10 and the ninth gear Z9. At the same time, the power on the intermediate shaft 8 is transmitted to the fourth output shaft 9 through the thirteenth gear Z13 and the fourteenth gear Z14.

[0090] Referring to Table 1, please refer to... Figure 6 In two-wheel drive and first gear mode, power is input from the first input shaft 1, transmitted to the intermediate shaft 8 via the planetary gear pair 10, and then transmitted to the third output shaft 5 via the twelfth gear Z12 and the eleventh gear Z11.

[0091] Referring to Table 1, please refer to... Figure 7 In two-wheel drive, second gear mode, power is input from the first input shaft 1, transmitted to the intermediate shaft 8 via the planetary gear pair 10, and then transmitted to the third output shaft 5 via the tenth gear Z10 and the ninth gear Z9.

[0092] Referring to Table 1, please refer to... Figure 8 In two-wheel drive and three-speed mode, power is input from the first input shaft 1 and the second input shaft 7, coupled through the planetary gear pair 10, and then transmitted to the intermediate shaft 8, and then to the third output shaft 5 through the twelfth gear Z12 and the eleventh gear Z11.

[0093] Referring to Table 1, please refer to... Figure 9 In two-wheel drive and four-speed mode, power is input from the first input shaft 1 and the second input shaft 7, coupled through the planetary gear pair 10, and then transmitted to the intermediate shaft 8, and then to the third output shaft 5 through the tenth gear Z10 and the ninth gear Z9.

[0094] Please refer to Figure 10 When the transmission system is operating in a state of simultaneous driving and work, it can simultaneously have the following power transmission paths:

[0095] The first input shaft 1 transmits power to the first output shaft 2;

[0096] The first input shaft 1 transmits power to the first output shaft 2, and then to the second output shaft 3 via the first output shaft 2;

[0097] The first input shaft 1 transmits power to the first output shaft 2, and then to the second input shaft 7 via the first output shaft 2, thereby achieving power coupling with the second input shaft 7;

[0098] After the second input shaft 7 is poweredly coupled to the first output shaft 2 through the planetary gear pair 10, it outputs to the intermediate shaft 8, and is then output by the intermediate shaft 8 to the third output shaft 5 and the fourth output shaft 9 respectively.

[0099] Through the above settings, when the electric tractor requires simultaneous output of traction power and implement operation, the basic requirement is that the target vehicle speed matches the drive implement speed to complete rotary tillage and other operations with high efficiency and quality. This solution's dual-motor coupling, direct-drive, and speed-adjustable performance, combined with an optimized shift sleeve arrangement, can handle multiple power output conditions while maintaining high operating efficiency for both the first motor 13 and the second motor 14, achieving high system efficiency, reducing energy consumption, and increasing continuous operating time. The dual-motor drive, matched with multiple shift sleeves, fully utilizes the motor's wide speed range and broad high-efficiency operating zone, optimizes the speed ratio configuration, reduces the number of gearbox gears, and meets the needs of multiple tractor operation conditions and high-efficiency operation under each condition. Simultaneously, the transmission should shift as few gears as possible during electric tractor operation, reducing shifting actions and improving overall machine operating efficiency.

[0100] Specifically, in practice, the first shift sleeve 4, the second shift sleeve 6, and the third shift sleeve 11 have the same structure. Furthermore, the first shift sleeve 4, the second shift sleeve 6, and the third shift sleeve 11 may also have the same dimensions.

[0101] In the configuration, the centerline of the first input shaft 1 and the centerline of the second output shaft 3 are on the same straight line; the centerline of the second input shaft 7 and the centerline of the third output shaft 5 are on the same straight line; the first input shaft 1, the first output shaft 2, the second input shaft 7, the intermediate shaft 8, and the fourth output shaft 9 are arranged in parallel. This configuration allows for a more compact transmission, reducing its size. It enables simultaneous output of multiple power sources, meeting the needs of various tractor operating modes. In specific implementation, the switching of the first shift sleeve 4, the second shift sleeve 6, and the third shift sleeve 11 is driven by electricity, hydraulic pressure, or pneumatic pressure.

[0102] Specifically, the transmission system in this embodiment is implemented through a transmission control unit (TCU). By using the TCU control unit, precise automatic gear shifting is achieved based on speed and traction requirements, which can meet the multi-power output requirements of tractor operation, achieve high operating efficiency, and reduce the labor intensity of the driver.

[0103] Specifically, the operating modes of the transmission in this embodiment are shown in Table 2 through the TCU control unit:

[0104] Table 2 Working Mode Table

[0105]

[0106]

[0107] In Table 2, √ indicates that the device is working or has power transmission, √or not indicates that it is either working or not working; a blank space indicates that the device is not working or has no power transmission.

[0108] In Table 2, the fourth shift sleeve is used to control whether power is output through the front axle. Under some operating conditions, whether power is output through the front axle does not affect the achievement of its working objective. Therefore, the fourth shift sleeve can be in an engaged or disengaged state.

[0109] Please refer to Table 2. The TCU controls the transmission system based on the acquired operating signals and vehicle status information, thereby enabling the transmission system to meet various gear shifting requirements. The transmission control unit receives signals and sends commands via the CAN bus to control the engagement state of the first shift sleeve 4, the second shift sleeve 6, the third shift sleeve 11, and the fourth shift sleeve 12. The TCU controls the automatic shifting function, which can more rationally control the number of shifts and the timing of shifts, so as to ensure that the motor operates within the efficient speed range and reduce the driver's workload.

[0110] As shown in Table 2, during unloaded start-up, the vehicle can be driven by the second motor alone in fourth gear, resulting in two-wheel drive (as mentioned earlier). Alternatively, it can be driven by the first motor alone in third gear, also resulting in two-wheel drive. Or, it can be driven by both the first motor 13 and the second motor 14 simultaneously in first or second gear, specifically either two-wheel drive first or second gear. The specific gear selection is determined by the operating status of the first motor 13 and the second motor 14, as well as the vehicle's condition. Of course, other conditions can also be used as a basis for selection, or the operator can directly select the gear.

[0111] As shown in Table 2, when starting under load, the vehicle can be driven by the first motor 13 alone in third gear, which can be either two-wheel drive or four-wheel drive. Alternatively, the first motor 13 and the second motor 14 can be driven simultaneously in first, second, third, or fourth gear, which can also be either four-wheel drive or two-wheel drive. The specific gear selection is determined by the operating status of the first motor 13 and the second motor 14, as well as the vehicle's condition. Of course, other conditions can also be used as a basis for selection, or the operator can directly select the gear.

[0112] As shown in Table 2, under low-to-medium speed transportation conditions, the gear can be third gear driven solely by the first motor 13, which is two-wheel drive; or it can be first, second, or third gear driven jointly by the first motor 13 and the second motor 14, which is also two-wheel drive. The specific gear selection can be determined by the operating status of the first motor 13 and the second motor 14, as well as the vehicle status, such as the target vehicle speed. Of course, other conditions can also be used as a basis for selection, or the operator can directly select the gear.

[0113] Under high-speed transportation conditions, it can operate in three or four gears when the first motor 13 and the second motor 14 are driven simultaneously; in this case, it is two-wheel drive. The specific gear selection can be based on the target vehicle speed.

[0114] In low-speed operating conditions where there is no drive for agricultural implements, i.e., in fields, orchards, or other operating environments where there is no drive for agricultural implements and the vehicle is traveling at low speed, the first motor 13 can drive the vehicle alone in third gear, which is either two-wheel drive or four-wheel drive. Alternatively, the second motor 14 can drive the vehicle alone in third gear, which is also two-wheel drive. The first motor 13 and the second motor 14 can also drive the vehicle together in first or second gear, which is either two-wheel drive or four-wheel drive.

[0115] In medium-speed operation without the output of drive implements, i.e., in fields, orchards, or other operating environments where there is no drive implement output and the tractor is traveling at medium speed, the first motor 13 can drive the tractor alone, placing it in third gear, with the drive mode being two-wheel drive or four-wheel drive. Alternatively, the first motor 13 and the second motor 14 can drive the tractor together, placing it in first, second, or third gear, with the drive mode being two-wheel drive or four-wheel drive. The specific gear selection can be determined by the operating status of the first motor 13 and the second motor 14, as well as the vehicle's status, such as the target speed. Of course, other conditions can also be used as a basis for selection, or the operator can directly select the gear.

[0116] In high-speed operation without the output of driven implements, i.e., in fields, or orchards where there is no output of driven implements and the vehicle is traveling at high speed, the power demand is high. This is achieved by the combined drive of the first motor 13 and the second motor 14. The gears can be first, second, third, or fourth, and the drive mode can be two-wheel drive or four-wheel drive. The specific gear selection can be determined by the vehicle's condition, such as the target speed. Alternatively, other conditions can be used as a basis for selection, or the operator can directly select the gear.

[0117] When the tractor is in motion and driving implements, the power demand is highest, which is also the tractor's normal operating condition. Under this condition, regardless of low, medium, or high speed, both the first motor 13 and the second motor 14 work together to drive the tractor. The gear can be selected as first, second, third, or fourth gear, and the drive mode can be two-wheel drive or four-wheel drive. The specific gear selection can be determined by the vehicle's condition, such as the target speed. Alternatively, other conditions can be used as a basis for selection, or the operator can directly select the gear.

[0118] Please refer to Table 2. Regarding reverse gear, although the transmission system provided in this embodiment does not have a separate reverse gear mechanism, it can still function as a reverse gear in conjunction with the TCU, the first motor 13, and the second motor 14. Specifically, reverse gear can be achieved by reversing the first motor 13. The transmission system can be in first, second, or third gear, and the drive mode can be two-wheel drive or four-wheel drive.

[0119] In this embodiment, the first shift sleeve 4, the second shift sleeve 6, the third shift sleeve 11, and the fourth shift sleeve 12 have the same structure, and their dimensions are selected as needed. The following description uses the first shift sleeve 4 as an example. Specifically, please refer to... Figure 12 The first shift sleeve 4 includes a sleeve body 41. The sleeve body 41, the third gear Z3, and the fifth gear Z5 are splined onto the second output shaft 3. The sleeve body 41 is located between the third gear Z3 and the fifth gear Z5, allowing the sleeve body 41 to slide between them. The sleeve body 41 is splined to the second output shaft 3, and its outer circumference is provided with external teeth. The surfaces of the third gear Z3 and the fifth gear Z5 opposite to the second output shaft 3 are provided with internal teeth. When the sleeve body 41 slides to the position of the gear to be driven, the external teeth of the sleeve body 41 can mesh with the internal teeth of the third gear Z3 or the fifth gear Z5 for transmission. A retaining ring 42, a spline washer 43, and an adjusting shim 44 are provided between the third gear Z3 and the fifth gear Z5 and the second output shaft 3.

[0120] Example 2

[0121] This embodiment is an application of Embodiment 1, that is, applying Embodiment 1 to an electric tractor. The content already disclosed in Embodiment 1 will not be repeated here. It should be noted that Embodiment 1 has a wide range of applications, and the electric tractor is only one of many application scenarios. This embodiment is merely an exemplary example and does not constitute a limitation on the application scope of Embodiment 1.

[0122] Please refer to Figure 1 This embodiment proposes an electric tractor, including a first motor 13, a second motor 14, a hydraulic pump, a rear axle drive shaft, a front axle drive shaft, and implements, and further including the transmission system as described in Embodiment 1. Specifically, the first motor 13 drives the first input shaft 1, and the second motor 14 drives the second input shaft 7. Specifically, the first motor 13 is connected to the first input shaft 1, and the second motor 14 is connected to the second input shaft 7; the hydraulic pump is connected to the first output shaft 2, the rear axle drive shaft is connected to the third output shaft 5, and the front axle drive shaft is connected to the fourth output shaft 9. That is, the first output shaft 2 drives the hydraulic pump of the electric tractor to establish a hydraulic system for the electric tractor. The second output shaft 3 drives the implements. The third output shaft 5 drives the rear axle of the electric tractor, and the fourth output shaft 9 drives the front axle of the electric tractor. The first motor 13 and the second motor 14 are permanent magnet synchronous motors or switched reluctance motors.

[0123] Through the above settings, when the electric tractor requires simultaneous output of traction power and implement operation, the basic requirement is that the target vehicle speed matches the drive implement speed to complete rotary tillage and other operations with high efficiency and high quality. This solution's dual-motor coupling, direct-drive, and speed-adjustable performance, combined with an optimized shift sleeve arrangement, can handle multiple power output conditions while maintaining high operating efficiency for both the first motor 13 and the second motor 14, achieving high system efficiency, reducing energy consumption, and increasing continuous operating time. The dual-motor drive, matched with multiple shift sleeves, fully utilizes the motor's wide speed range and broad high-efficiency operating zone, optimizes the speed ratio configuration, reduces the number of gearbox gears, and meets the needs of multiple tractor operation conditions and high-efficiency operation under each condition. Simultaneously, the transmission should shift as few gears as possible during electric tractor operation, reducing shifting actions and improving overall machine operating efficiency.

[0124] The above description, based on the embodiments shown in the figures, details the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention, but the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A transmission system, characterized in that: include, First input axis (1); The first output shaft (2) is connected to the first input shaft (1) in a transmission manner; The second output shaft (3) is provided with a first shift sleeve (4); the first shift sleeve (4) is used to realize the power transmission or interruption between the second output shaft (3) and the first input shaft (1); the second output shaft (3) can have a constant output speed when working; The third output shaft (5) is connected to the first input shaft (1) in a transmission manner. The third output shaft (5) is provided with a second shift sleeve (6). The second shift sleeve (6) is used to realize the power transmission or interruption of the third output shaft (5). It also includes a second input shaft (7), an intermediate shaft (8), and a fourth output shaft (9); A planetary gear pair (10) is mounted on the second input shaft (7); the second input shaft (7) is connected to the first output shaft (2) and the intermediate shaft (8) respectively through the planetary gear pair (10); A third shift sleeve (11) is installed on the second input shaft (7). The third shift sleeve (11) is used to realize the engagement or disengagement between the sun gear (101) of the planetary gear pair (10) and the planet carrier (102) of the planetary gear pair (10). The fourth output shaft (9) is provided with a fourth shift sleeve (12), which is used to realize the power transmission or interruption between the fourth output shaft (9) and the intermediate shaft (8); The third output shaft (5) is connected to the intermediate shaft (8) in a transmission connection.

2. The transmission system according to claim 1, characterized in that: The second input shaft (7) is fixedly connected to the sun gear (101) of the planetary gear pair (10); the first output shaft (2) is driven to the gear ring (103) of the planetary gear pair (10); the intermediate shaft (8) is driven to the planet carrier (102) of the planetary gear pair (10).

3. The transmission system according to claim 1, characterized in that: The reversal of the third output shaft (5) and the fourth output shaft (9) is achieved by the reversal of the first output shaft (2) and / or the second output shaft (3).

4. The transmission system according to claim 1, characterized in that: When the third output shaft (5) has power output and the fourth output shaft (9) does not have power output: the transmission system has at least four gear positions; When both the third output shaft (5) and the fourth output shaft (9) have power output, there are at least four gear positions.

5. The transmission system according to any one of claims 1-4, characterized in that: When the transmission system is in operation, it can simultaneously have the following power transmission paths: The first input shaft (1) transmits power to the first output shaft (2); The first input shaft (1) transmits power to the first output shaft (2), and then to the second output shaft (3) via the first output shaft (2). The first input shaft (1) transmits power to the first output shaft (2), and then transmits it to the second input shaft (7) via the first output shaft (2), thereby achieving power coupling with the second input shaft (7); After the second input shaft (7) is poweredly coupled to the first output shaft (2) through the planetary gear pair (10), it is output to the intermediate shaft (8), and then output to the third output shaft (5) and the fourth output shaft (9) respectively by the intermediate shaft (8).

6. The transmission system according to any one of claims 1-4, characterized in that: The first shift sleeve (4), the second shift sleeve (6) and the third shift sleeve (11) have the same structure.

7. The transmission system according to any one of claims 1-4, characterized in that: The centerline of the first input shaft (1) and the centerline of the second output shaft (3) are on the same straight line; The centerline of the second input shaft (7) and the centerline of the third output shaft (5) are on the same straight line; The first input shaft (1), the first output shaft (2), the second input shaft (7), the intermediate shaft (8), and the fourth output shaft (9) are arranged in parallel.

8. The transmission system according to any one of claims 1-4, characterized in that: The switching of the first shift sleeve (4), the second shift sleeve (6) and the third shift sleeve (11) is driven by electricity, hydraulic pressure or pneumatic pressure.

9. An electric tractor, comprising a first motor (13), a second motor (14), a hydraulic pump, a rear axle drive shaft, a front axle drive shaft, and implements, characterized in that: It also includes the transmission system as described in any one of claims 1-8; The first motor (13) is connected to the first input shaft (1), the second motor (14) is connected to the second input shaft (7); the hydraulic pump is connected to the first output shaft (2), the rear axle drive shaft is connected to the third output shaft (5), and the front axle drive shaft is connected to the fourth output shaft (9).

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