Novel electric drive axle of pure electric tractor and electric drive axle control method

Abstract

The invention relates to the technical field of electric drive axles, and discloses a novel electric drive axle of a pure electric tractor and an electric drive axle control method.The electric drive axle is characterized in that a first clutch is arranged between a first motor and a first high-gear gear set, and a second clutch is arranged between the first motor and a first low-gear gear set; a fourth clutch is arranged between the second motor and the second high-gear gear set, and a third clutch is arranged between the second motor and the second low-gear gear set; the first high-gear gear set, the first low-gear gear set, the second high-gear gear set and the second low-gear gear set are in transmission connection with the central differential mechanism; the central differential mechanism is in transmission connection with the first wheel through the first half shaft and the first final transmission mechanism, and the central differential mechanism is in transmission connection with the second wheel through the second half shaft and the second final transmission mechanism. The double motors are symmetrically arranged, the structure is compact, a high gear and a low gear are arranged, and the operation and transfer requirements can be met; centralized driving and distributed driving are achieved, and the use performance of the electric drive axle is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric drive axles, and in particular to a new electric drive axle for a pure electric tractor and an electric drive axle control method. Background Art

[0002] Pure electric tractors have become a hot topic of research due to their significant advantages in environmental protection, economy, high efficiency and modern agriculture. Among them, the travel system of the tractor is the key to the development of pure electric tractors, which directly affects the dynamic performance of the tractor in complex working environments. The electric drive axle has the advantages of compact structure and strong versatility. How to optimize the space utilization of the electric drive axle while meeting the different working conditions of the tractor is a problem that needs to be solved urgently.

[0003] At present, the research on electric drive axles in existing patents is basically similar in structure to the layout of traditional fuel vehicle drive systems, except that the power source is changed from the engine to the motor. For example, the invention patent with the patent authorization announcement number CN115366644B proposes an electric drive axle that uses two independent drive systems to achieve multi-speed drive. When one of the drive systems shifts gears, the other drive system maintains the power output state, which can achieve non-power interruption shifting. However, the drive system has the defect of occupying a large space, and adopts the traditional centralized drive mode. In working conditions such as split roads, additional mechanical devices are required to achieve drive anti-slip control, which is costly and has complex control logic. The invention patent with the application publication number CN119189663A proposes an electric drive axle for commercial vehicles. The electric drive axle uses a drive motor, which can provide driving function while driving the vehicle, occupies a small space, and has low manufacturing cost, but it is also unable to adapt to the complex driving conditions of tractors. The invention patent with application publication number CN119239292A proposed two electric drive axle layouts and selected different numbers of drive motors, but it is not suitable for the complex working conditions of tractors. The invention patent with application publication number CN119283599A uses a main and auxiliary dual motor to drive the vehicle with multiple gears, but it also cannot achieve vehicle dynamics control. In the patent with patent authorization announcement number CN118991458B, considering the slippage problem of multi-axle vehicles, a power control method for dual electric drive axles is proposed. This method can solve the slippage problem of the front and rear axles, but it cannot solve the slippage problem of the left and right wheels of a single electric drive axle.

[0004] Therefore, it is urgent to provide a technical solution to solve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a new electric drive axle of a pure electric tractor and an electric drive axle control method.

[0006] In a first aspect, the present invention provides a new electric drive axle for a pure electric tractor. The technical solution of the new electric drive axle for a pure electric tractor is as follows: The invention comprises: a first motor, a second motor, a first high gear set, a first low gear set, a second high gear set, a second low gear set, a central differential, a first half shaft, a second half shaft, a first final transmission mechanism, a second final transmission mechanism, a first wheel, and a second wheel; A first clutch is provided between the first motor and the first high-speed gear set, a second clutch is provided between the first motor and the first low-speed gear set, and the operation states of the first clutch and the second clutch are opposite; a fourth clutch is provided between the second motor and the second high-speed gear set, a third clutch is provided between the second motor and the second low-speed gear set, and the operation states of the third clutch and the fourth clutch are opposite; The first high-speed gear set, the first low-speed gear set, the second high-speed gear set and the second low-speed gear set are all drivingly connected to the central differential; the first output end of the central differential is drivingly connected to the first wheel through the first half-shaft and the first final drive mechanism, and the second output end of the central differential is drivingly connected to the second wheel through the second half-shaft and the second final drive mechanism.

[0007] The beneficial effects of the new electric drive axle of a pure electric tractor of the present invention are as follows: The new electric drive axle of the pure electric tractor of the present invention adopts a symmetrical arrangement of dual motors, has a compact structure, and has two high and low gears, which can meet the needs of operation and transportation; the electric drive axle can realize both centralized drive and distributed drive, improves the use performance of the electric tractor, and has extremely high application value.

[0008] On the basis of the above scheme, the new electric drive axle of a pure electric tractor of the present invention can also be improved as follows.

[0009] In an optional manner, the low gear working mode of the new electric drive axle of the pure electric tractor is: The second clutch and the third clutch are in an engaged state, the first clutch and the fourth clutch are in a disengaged state, the power of the first motor is transmitted to the central differential through the first low gear set, and the power of the second motor is transmitted to the central differential through the second low gear set; the central differential evenly distributes the coupled power to the first half-shaft and the second half-shaft, drives the first wheel through the first half-shaft and the first final drive mechanism, and drives the second wheel through the second half-shaft and the second final drive mechanism.

[0010] In an optional manner, the high-speed working mode of the new electric drive axle of the pure electric tractor is: The first clutch and the fourth clutch are in an engaged state, the second clutch and the third clutch are in a disengaged state, the power of the first motor is transmitted to the central differential through the first high-speed gear set, and the power of the second motor is transmitted to the central differential through the second high-speed gear set; the central differential evenly distributes the coupled power to the first half-shaft and the second half-shaft, drives the first wheel through the first half-shaft and the first final drive mechanism, and drives the second wheel through the second half-shaft and the second final drive mechanism.

[0011] In an optional manner, the driving anti-skid mode of the new electric drive axle of the pure electric tractor is: When the new electric drive axle of the pure electric tractor is in the low-gear working mode and one side of the wheel slips, it switches to the high-gear working mode, increases the torque of the motor corresponding to the other side of the wheel, and reduces the torque of the motor corresponding to the one side of the wheel.

[0012] In an optional manner, the extreme turning mode of the new electric drive axle of the pure electric tractor is: When the new electric drive axle of the pure electric tractor is in the low-gear working mode and turns to one side, it will switch to the high-gear working mode, and control the motor torque of the other side to output forward and the motor torque of the one side to output reverse.

[0013] In an optional manner, the single motor driving mode of the new electric drive axle of the pure electric tractor is: When one of the motors of the novel electric drive axle of the pure electric tractor fails, the clutch between the other motor and the corresponding low-speed gear set is controlled to be in an engaged state, and the remaining clutches are controlled to be in a disconnected state.

[0014] In a second aspect, the present invention provides a new electric drive axle control method for a pure electric tractor, and the technical solution of the method is as follows: Acquire the current operating state of a tractor equipped with a target electric drive axle; the target electric drive axle is a new electric drive axle for a pure electric tractor of the present invention; Based on the current operating state, a current operating mode of the target electric drive axle is determined, and the target electric drive axle is controlled to execute the current operating mode.

[0015] The beneficial effects of the novel electric drive axle control method for a pure electric tractor of the present invention are as follows: The novel electric drive axle control strategy proposed by the method of the present invention can actively control the drive motor and the clutch according to the working conditions of the tractor, thereby realizing automatic switching of the required modes.

[0016] On the basis of the above scheme, the novel electric drive axle control method for a pure electric tractor of the present invention can also be improved as follows.

[0017] In an optional manner, the step of determining the current operating mode of the target electric drive axle based on the current operating state includes: When the current operating state is wheel slip, determining the current operating mode as a driving anti-skid mode; Wherein, the driving anti-skid mode is: when the target electric drive axle is in the low-gear working mode and one side of the wheel slips, it switches to the high-gear working mode, and increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to the one side of the wheel; when the target electric drive axle is in the high-gear working mode, increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to the one side of the wheel; The low gear working mode is as follows: the second clutch and the third clutch are in an engaged state, the first clutch and the fourth clutch are in a disengaged state, the power of the first motor is transmitted to the central differential through the first low gear set, and the power of the second motor is transmitted to the central differential through the second low gear set; The high-gear working mode is as follows: the first clutch and the fourth clutch are in an engaged state, the second clutch and the third clutch are in a disengaged state, the power of the first motor is transmitted to the central differential through the first high-gear gear set, and the power of the second motor is transmitted to the central differential through the second high-gear gear set; In the low-gear working mode and the high-gear working mode, the central differential evenly distributes the coupled power to the first half-shaft and the second half-shaft, drives the first wheel through the first half-shaft and the first final drive mechanism, and drives the second wheel through the second half-shaft and the second final drive mechanism.

[0018] In an optional manner, the step of determining the current operating mode of the target electric drive axle based on the current operating state further includes: When the current operating state is extreme turning, the current operating mode is determined as the extreme turning mode; wherein, the extreme turning mode is: when the target electric drive axle is in the low-gear working mode and turns to one side, it will switch to the high-gear working mode, and control the forward output of the motor torque on the other side and the reverse output of the motor torque on the one side.

[0019] In an optional manner, the step of determining the current operating mode of the target electric drive axle based on the current operating state further includes: When the current operating state is a motor failure, the current operating mode is determined as a single-motor drive mode; wherein the single-motor drive mode is: when one of the motors of the target electric drive axle fails, the clutch between the other motor and the corresponding low-speed gear set is controlled to be in an engaged state, and the remaining clutches are controlled to be in a disconnected state.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings: Figure 1 It is a structural schematic diagram of an embodiment of a new electric drive axle of a pure electric tractor of the present invention; Figure 2 This is a schematic diagram of the principle of the low-speed working mode; Figure 3 This is a schematic diagram of the principle of the high-speed working mode; Figure 4 It is a schematic diagram of the principle of driving anti-skid mode; Figure 5 This is a schematic diagram of the principle of the extreme turning mode; Figure 6 It is a schematic diagram of the principle of single motor driving mode; Figure 7 It is a flow chart of an embodiment of a new electric drive axle control method for a pure electric tractor of the present invention; Figure 8 It is the principle schematic diagram of the low gear control strategy of the electric drive axle; Fig. 9 This is a schematic diagram of the principle of the high-gear control strategy for the electric drive axle.

[0022] Among them, 101 represents the first motor, 102 represents the first clutch, 103 represents the second clutch, 104 represents the third clutch, 105 represents the fourth clutch, 106 represents the second motor, 107 represents the second wheel, 108 represents the second final transmission mechanism, 109 represents the second half shaft, 110 represents the second high-speed gear set, 111 represents the second low-speed gear set, 112 represents the central differential, 113 represents the first low-speed gear set, 114 represents the first high-speed gear set, 115 represents the first half shaft, 116 represents the first final transmission mechanism, and 117 represents the first wheel. DETAILED DESCRIPTION

[0023] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0024] Figure 1 FIG. 1 is a schematic diagram showing a structure of an embodiment of a new electric drive axle of a pure electric tractor provided by the present invention. Figure 1 As shown, the new electric drive axle of the pure electric tractor includes: a first motor 101, a second motor 106, a first high-speed gear set 114, a first low-speed gear set 113, a second high-speed gear set 110, a second low-speed gear set 111, a central differential 112, a first half shaft 115, a second half shaft 109, a first final transmission mechanism 116, a second final transmission mechanism 108, a first wheel 117 and a second wheel 107.

[0025] A first clutch 102 is provided between the first motor 101 and the first high gear set 114, a second clutch 103 is provided between the first motor 101 and the first low gear set 113, and the operation states of the first clutch 102 and the second clutch 103 are opposite. A fourth clutch 105 is provided between the second motor 106 and the second high gear set 110, a third clutch 104 is provided between the second motor 106 and the second low gear set 111, and the operation states of the third clutch 104 and the fourth clutch 105 are opposite.

[0026] Among them, when the first motor 101 operates normally, the first clutch 102 is engaged and the second clutch 103 is disconnected; the first clutch 102 is disconnected and the second clutch 103 is engaged; when the second motor 106 operates normally, the third clutch 104 is engaged and the fourth clutch 105 is disconnected; the third clutch 104 is disconnected and the fourth clutch 105 is engaged.

[0027] The first high gear set 114, the first low gear set 113, the second high gear set 110 and the second low gear set 111 are all connected to the central differential 112; the first output end of the central differential 112 is connected to the first wheel 117 through the first half shaft 115 and the first final transmission mechanism 116, and the second output end of the central differential 112 is connected to the second wheel 107 through the second half shaft 109 and the second final transmission mechanism 108.

[0028] In an optional manner, the low gear working mode of the new electric drive axle of the pure electric tractor is: The second clutch 103 and the third clutch 104 are in an engaged state, the first clutch 102 and the fourth clutch 105 are in a disengaged state, the power of the first motor 101 is transmitted to the central differential 112 through the first low gear set 113, and the power of the second motor 106 is transmitted to the central differential 112 through the second low gear set 111; the central differential 112 evenly distributes the coupled power to the first half-shaft 115 and the second half-shaft 109, drives the first wheel 117 through the first half-shaft 115 and the first final drive mechanism 116, and drives the second wheel 107 through the second half-shaft 109 and the second final drive mechanism 108.

[0029] Among them, the power transmission path of the low-speed working mode of the new electric drive axle of the pure electric tractor is as follows: Figure 2 As shown, TL represents the drive torque at the first wheel 117 , TR represents the drive torque at the second wheel 107 , and TL=TR.

[0030] In an optional manner, the high-speed working mode of the new electric drive axle of the pure electric tractor is: The first clutch 102 and the fourth clutch 105 are in an engaged state, the second clutch 103 and the third clutch 104 are in a disengaged state, the power of the first motor 101 is transmitted to the central differential 112 through the first high-speed gear set 114, and the power of the second motor 106 is transmitted to the central differential 112 through the second high-speed gear set 110; the central differential 112 evenly distributes the coupled power to the first half-shaft 115 and the second half-shaft 109, drives the first wheel 117 through the first half-shaft 115 and the first final transmission mechanism 116, and drives the second wheel 107 through the second half-shaft 109 and the second final transmission mechanism 108.

[0031] Among them, the power transmission path of the high-speed working mode of the new electric drive axle of the pure electric tractor is as follows: Figure 3 As shown in the figure, the high gear has a smaller transmission ratio than the low gear, which can increase the maximum speed of the tractor, and TL=TR.

[0032] In an optional manner, the driving anti-skid mode of the new electric drive axle of the pure electric tractor is: When the new electric drive axle of the pure electric tractor is in the low-gear working mode and one side of the wheel slips, it switches to the high-gear working mode, and increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to one side of the wheel.

[0033] In the low gear working mode, when one side of the wheel slips, the vehicle is easily stuck due to the characteristic of the differential that the differential does not differentiate the torque. For example, when the second wheel 107 slips, Figure 4As shown, at this time, the second clutch 103 and the third clutch 104 are disconnected, the first clutch 102 and the fourth clutch 105 are engaged, and the high gear working mode is switched to control the first motor 101 to increase the torque output, and the second motor 106 to reduce the torque output, so that TL>TR, and the tractor can be freed. It should be noted that the control principle after the first wheel 117 slips is similar and will not be described in detail.

[0034] In an optional manner, the extreme turning mode of the new electric drive axle of the pure electric tractor is: When the new electric drive axle of the pure electric tractor is in the low-gear working mode and turns to one side, it will switch to the high-gear working mode and control the motor torque on the other side to output in the forward direction and the motor torque on one side to output in the reverse direction.

[0035] Among them, tractors equipped with new electric drive axles of pure electric tractors have limited turning space in certain special working environments (such as narrow roads, etc.). Take right turns as an example. Figure 5 As shown, the second clutch 103 is disconnected from the third clutch 104, the first clutch 102 is engaged with the fourth clutch 105, and the high gear working mode is switched to control the first motor 101 to output torque in the forward direction and the second motor 106 to output torque in the reverse direction. The tractor can achieve fast turning, significantly reduce the turning radius, and improve the passability.

[0036] In an optional manner, the single motor drive mode of the new electric drive axle of the pure electric tractor is: When one of the motors of the new electric drive axle of the pure electric tractor fails, the clutch between the other motor and the corresponding low-speed gear set is controlled to be in an engaged state, and the remaining clutches are controlled to be in a disconnected state.

[0037] If the motor fails during the operation of the tractor, the tractor will face the risk of stopping and it will be difficult to transport it to a repair site, which is very inconvenient. However, the electric drive axle proposed in this embodiment can move the tractor to a suitable position by driving a single motor. Figure 6 As shown, taking the failure of the first motor 101 and the normal operation of the second motor 106 as an example, the third clutch 104 remains engaged, the other clutches are disconnected, and the power is transmitted from the second motor 106 to the first wheel 117 and the second wheel 107.

[0038] The electric drive axle of the technical solution of this embodiment adopts a symmetrical arrangement of dual motors, has a compact structure, and has two high and low gears, which can meet the needs of operation and transportation. The electric drive axle can realize both centralized drive and distributed drive. On this basis, the torque of each wheel is independently controllable, which is helpful for the vehicle to escape and control stability under the working conditions of open roads and muddy roads. In working environments such as hills, orchards, paddy fields, and greenhouses, the turning space of the tractor is limited. The electric drive axle can reduce the turning radius of the tractor by the differential drive of the drive motor and its own steering system, which is conducive to the application of narrow spaces. When a traditional electric tractor has a motor failure, it can only stop and wait for rescue. However, when a single-side motor fails, the new electric drive axle can transfer the vehicle to a safe area for maintenance in a centralized drive mode by the remaining normal drive motor, which improves the fault redundancy capability of the tractor and has a very high application value.

[0039] Figure 7 The flowchart of an embodiment of a new electric drive axle control method for a pure electric tractor provided by the present invention is shown, which is executed by the vehicle VCU. Figure 7 As shown, the method comprises the following steps: S1. Obtain the current operating status of the tractor equipped with the target electric drive axle.

[0040] The target electric drive axle adopts the new electric drive axle of the pure electric tractor of the present invention, and the new electric drive axle of the pure electric tractor is arranged on the tractor. The current operating state of the tractor is collected in real time by the wheel slip detection system integrated in the vehicle VCU arranged on the tractor. The operating state includes: wheel slip, extreme turning, motor failure and normal state, etc., which are not limited here. The current operating state is any one of the above operating states.

[0041] It should be noted that the wheel slip judgment condition is: the wheel slip rate is greater than the threshold (the default setting is 5%-20%, which can be adjusted according to the actual situation and is not limited here). The wheel slip rate is: the ratio of the relative difference between the wheel linear velocity and the vehicle speed to the wheel linear velocity: Sd=(rw-v) / rw*100%; Sd is the wheel slip rate, r is the wheel radius, w is the wheel angular velocity, rw is the wheel linear velocity, and v is the actual vehicle speed.

[0042] S2. Based on the current operating state, determine the current operating mode of the target electric drive axle, and control the target electric drive axle to execute the current operating mode.

[0043] Among them, the operating modes include: low-gear working mode, high-gear working mode, drive anti-skid mode, extreme turning mode and single-motor drive mode, etc.

[0044] In an optional manner, S2 includes: When the current operating state is wheel slip, the current operating mode is determined as a driving anti-skid mode; Among them, the drive anti-skid mode is: when the target electric drive axle is in the low-gear working mode and one side of the wheel slips, it switches to the high-gear working mode, and increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to one side of the wheel; when the target electric drive axle is in the high-gear working mode, increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to one side of the wheel.

[0045] Among them, the low gear working mode is: the second clutch 103 and the third clutch 104 are in an engaged state, the first clutch 102 and the fourth clutch 105 are in a disengaged state, the power of the first motor 101 is transmitted to the central differential 112 through the first low gear set 113, and the power of the second motor 106 is transmitted to the central differential 112 through the second low gear set 111.

[0046] Among them, the high gear working mode is: the first clutch 102 and the fourth clutch 105 are in an engaged state, the second clutch 103 and the third clutch 104 are in a disengaged state, the power of the first motor 101 is transmitted to the central differential 112 through the first high gear set 114, and the power of the second motor 106 is transmitted to the central differential 112 through the second high gear set 110.

[0047] In the low gear working mode and the high gear working mode, the central differential 112 evenly distributes the coupled power to the first half-shaft 115 and the second half-shaft 109 , drives the first wheel 117 through the first half-shaft 115 and the first final drive mechanism 116 , and drives the second wheel 107 through the second half-shaft 109 and the second final drive mechanism 108 .

[0048] In an optional manner, S2 further includes: When the current operating state is extreme turning, the current operating mode is determined as the extreme turning mode; wherein, the extreme turning mode is: when the target electric drive axle is in the low-gear working mode and turns to one side, it will switch to the high-gear working mode, and control the motor torque on the other side to be output in the forward direction and the motor torque on one side to be output in the reverse direction.

[0049] In an optional manner, S2 further includes: When the current operating state is a motor failure, the current operating mode is determined to be a single-motor drive mode.

[0050] Among them, the single-motor drive mode is: when one of the motors of the target electric drive axle fails, the clutch between the other motor and the corresponding low-speed gear set is controlled to be in an engaged state, and the remaining clutches are controlled to be in a disconnected state.

[0051] It should be noted that the new electric drive axle of the pure electric tractor in this embodiment has two gears, high and low. The low gear is mainly responsible for operation, and the high gear is responsible for transfer. Specifically, the speed of the pure electric tractor can be used to determine whether the pure electric tractor is in a low gear working mode (high engine speed, low wheel speed) or a high gear working mode (low engine speed, high wheel speed). When the pure electric tractor is in the low gear working mode, the low gear control strategy of the electric drive axle is as follows: Figure 8 As shown, during the working process, the pure electric tractor switches between the low-gear working mode and the high-gear working mode in a timely manner; the wheel slip detection system operates in real time, and when it is determined that the wheel is in a slipping state, the second clutch 103 and the third clutch 104 are disconnected, the first clutch 102 and the fourth clutch 105 are engaged, and the working mode is switched to the high-gear working mode. After the switching is completed, the wheel driving torque is actively controlled (the motor is controlled to change the torque), and the slip detection is continued. When it is determined that there is no slip phenomenon, the second clutch 103 and the third clutch 104 are engaged, the first clutch 102 and the fourth clutch 105 are disconnected, and the working mode is restored to the low-gear working mode; when the extreme turning command is received, the first clutch 102 and the fourth clutch 105 are disconnected, and the working mode is restored to the low-gear working mode. The second clutch 103 and the third clutch 104 are disconnected, the first clutch 102 and the fourth clutch 105 are engaged, and the working mode is switched to the high gear. After the switching is completed, the wheel drive torque is actively controlled. After the steering is completed, the second clutch 103 and the third clutch 104 are engaged, the first clutch 102 and the fourth clutch 105 are disconnected, and the working mode is restored to the low gear. When the first motor 101 fails, the second clutch 103 is disconnected, the third clutch 104 is engaged, and the pure electric tractor is transferred to a safe area. When the second motor 106 fails, the third clutch 104 is disconnected, the second clutch 103 is engaged, and the pure electric tractor is transferred to a safe area.

[0052] It should be noted that when the pure electric tractor is in high gear working mode, the high gear control strategy of the electric drive axle is as follows: Fig. 9 As shown, during the working process, the pure electric tractor switches between the high-gear working mode and the low-gear working mode in a timely manner; the wheel slip detection system runs in real time, and when it is determined that the wheel is in a slipping state, the wheel drive torque is actively controlled, and the slip detection is continued. When the slip phenomenon is eliminated, the pure electric tractor maintains the high-gear working mode; when the extreme turning command is received, the wheel drive torque is actively controlled, and after the turning is completed, the high-gear working mode is maintained; when the first motor 101 fails, the first clutch 102 is disconnected, the third clutch 104 is engaged, and the pure electric tractor is transferred to a safe area. When the second motor 106 fails, the fourth clutch 105 is disconnected, the second clutch 103 is engaged, and the pure electric tractor is transferred to a safe area.

[0053] The new electric drive axle control strategy proposed in the technical solution of this embodiment can actively control the drive motor and clutch according to the working conditions of the tractor, realize automatic switching of the required modes, improve the performance of the electric tractor, and has extremely high promotion value.

[0054] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. Similarly, in order to simplify the present invention and help understand one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the embodiments of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. Wherein, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself is a separate embodiment of the present invention.

[0055] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names. The steps in the above embodiments, unless otherwise specified, should not be understood as limitations on the order of execution.

Claims

1. A new electric drive axle for a pure electric tractor, characterized in that: include: A first motor (101), a second motor (106), a first high gear set (114), a first low gear set (113), a second high gear set (110), a second low gear set (111), a central differential (112), a first half shaft (115), a second half shaft (109), a first final drive mechanism (116), a second final drive mechanism (108), a first wheel (117), and a second wheel (107); A first clutch (102) is arranged between the first motor (101) and the first high-gear gear set (114), a second clutch (103) is arranged between the first motor (101) and the first low-gear gear set (113), and the operating states of the first clutch (102) and the second clutch (103) are opposite; a fourth clutch (105) is arranged between the second motor (106) and the second high-gear gear set (110), a third clutch (104) is arranged between the second motor (106) and the second low-gear gear set (111), and the operating states of the third clutch (104) and the fourth clutch (105) are opposite; The first high-speed gear set (114), the first low-speed gear set (113), the second high-speed gear set (110) and the second low-speed gear set (111) are all drivingly connected to the central differential (112); the first output end of the central differential (112) is drivingly connected to the first wheel (117) via the first half-shaft (115) and the first final transmission mechanism (116), and the second output end of the central differential (112) is drivingly connected to the second wheel (107) via the second half-shaft (109) and the second final transmission mechanism (108).

2. The new electric drive axle of a pure electric tractor according to claim 1 is characterized in that: The low gear working mode of the new electric drive axle of the pure electric tractor is: The second clutch (103) and the third clutch (104) are in an engaged state, the first clutch (102) and the fourth clutch (105) are in a disengaged state, the power of the first motor (101) is transmitted to the central differential (112) through the first low gear set (113), and the power of the second motor (106) is transmitted to the central differential (112) through the second low gear set (111); the central differential (112) evenly distributes the coupled power to the first half-shaft (115) and the second half-shaft (109), drives the first wheel (117) through the first half-shaft (115) and the first final transmission mechanism (116), and drives the second wheel (107) through the second half-shaft (109) and the second final transmission mechanism (108).

3. The new electric drive axle of a pure electric tractor according to claim 2 is characterized in that: The high gear working mode of the new electric drive axle of the pure electric tractor is: The first clutch (102) and the fourth clutch (105) are in an engaged state, the second clutch (103) and the third clutch (104) are in a disengaged state, the power of the first motor (101) is transmitted to the central differential (112) through the first high-speed gear set (114), and the power of the second motor (106) is transmitted to the central differential (112) through the second high-speed gear set (110); the central differential (112) evenly distributes the coupled power to the first half-shaft (115) and the second half-shaft (109), drives the first wheel (117) through the first half-shaft (115) and the first final transmission mechanism (116), and drives the second wheel (107) through the second half-shaft (109) and the second final transmission mechanism (108).

4. The new electric drive axle of a pure electric tractor according to claim 3 is characterized in that: The driving anti-skid mode of the new electric drive axle of the pure electric tractor is: When the new electric drive axle of the pure electric tractor is in the low-gear working mode and one side of the wheel slips, it switches to the high-gear working mode, increases the torque of the motor corresponding to the other side of the wheel, and reduces the torque of the motor corresponding to the one side of the wheel.

5. The new electric drive axle of a pure electric tractor according to claim 3 is characterized in that: The extreme turning mode of the new electric drive axle of the pure electric tractor is: When the new electric drive axle of the pure electric tractor is in the low-gear working mode and turns to one side, it will switch to the high-gear working mode, and control the motor torque of the other side to output forward and the motor torque of the one side to output reverse.

6. The new electric drive axle for a pure electric tractor according to any one of claims 2 to 5, characterized in that: The single motor driving mode of the new electric drive axle of the pure electric tractor is: When one of the motors of the novel electric drive axle of the pure electric tractor fails, the clutch between the other motor and the corresponding low-speed gear set is controlled to be in an engaged state, and the remaining clutches are controlled to be in a disconnected state.

7. A new electric drive axle control method for a pure electric tractor, characterized in that: include: Get the current operating status of the tractor equipped with the target electric drive axle; The target electric drive axle adopts the new electric drive axle of the pure electric tractor as claimed in claim 1; Based on the current operating state, a current operating mode of the target electric drive axle is determined, and the target electric drive axle is controlled to execute the current operating mode.

8. The new electric drive axle control method for a pure electric tractor according to claim 7, characterized in that: Based on the current operating state, the step of determining the current operating mode of the target electric drive axle includes: When the current operating state is wheel slip, determining the current operating mode as a driving anti-skid mode; Wherein, the driving anti-skid mode is: when the target electric drive axle is in the low-gear working mode and one side of the wheel slips, it switches to the high-gear working mode, and increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to the one side of the wheel; when the target electric drive axle is in the high-gear working mode, increases the torque of the motor corresponding to the other side of the wheel and reduces the torque of the motor corresponding to the one side of the wheel; The low gear working mode is as follows: the second clutch (103) and the third clutch (104) are in an engaged state, the first clutch (102) and the fourth clutch (105) are in a disengaged state, the power of the first motor (101) is transmitted to the central differential (112) via the first low gear set (113), and the power of the second motor (106) is transmitted to the central differential (112) via the second low gear set (111); The high-gear working mode is as follows: the first clutch (102) and the fourth clutch (105) are in an engaged state, the second clutch (103) and the third clutch (104) are in a disengaged state, the power of the first motor (101) is transmitted to the central differential (112) via the first high-gear gear set (114), and the power of the second motor (106) is transmitted to the central differential (112) via the second high-gear gear set (110); In the low-gear working mode and the high-gear working mode, the central differential (112) evenly distributes the coupled power to the first half-shaft (115) and the second half-shaft (109), drives the first wheel (117) through the first half-shaft (115) and the first final drive mechanism (116), and drives the second wheel (107) through the second half-shaft (109) and the second final drive mechanism (108).

9. The new electric drive axle control method for a pure electric tractor according to claim 8, characterized in that: The step of determining the current operating mode of the target electric drive axle based on the current operating state further includes: When the current operating state is extreme turning, the current operating mode is determined as the extreme turning mode; wherein, the extreme turning mode is: when the target electric drive axle is in the low-gear working mode and turns to one side, it will switch to the high-gear working mode, and control the forward output of the motor torque on the other side and the reverse output of the motor torque on the one side.

10. The new electric drive axle control method for a pure electric tractor according to claim 8, characterized in that: The step of determining the current operating mode of the target electric drive axle based on the current operating state further includes: When the current operating state is a motor failure, the current operating mode is determined as a single-motor drive mode; wherein the single-motor drive mode is: when one of the motors of the target electric drive axle fails, the clutch between the other motor and the corresponding low-speed gear set is controlled to be in an engaged state, and the remaining clutches are controlled to be in a disconnected state.

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