Electric excavator based on distributed electro-hydrostatic direct drive system

Abstract

The invention discloses an electric excavator based on a distributed electro-hydrostatic direct drive system. The electric excavator comprises a low-voltage control assembly, a high-voltage power source assembly, a motor drive assembly, a rotation drive assembly, a motor pump assembly, an independent speed regulating valve assembly, a flow distribution valve assembly and an actuator assembly. According to the electric excavator, three motor pumps are adopted to independently drive a movable arm, a bucket rod and a bucket in a distributed mode, a rotary electric drive system is adopted to independently drive an upper vehicle to rotate, flow distribution valves are arranged to achieve flow distribution and flow combination of the bucket rod motor pumps and the bucket motor pumps, and a walking motor is driven through oil way switching of a flow distribution valve set; the problems of pressure coupling loss, throttling loss and the like of a large number of multiple actuators due to the fact that a traditional electric excavator adopts a centralized hydraulic transmission system are solved, the transmission energy efficiency of the whole machine is improved through distributed independent driving, movable arm potential energy recovery and rotation braking kinetic energy recovery, and the energy consumption of the whole machine is reduced. And the cruising ability of the electric excavator is fully improved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction machinery, and more particularly, to an electric excavator based on a distributed electro-hydrostatic direct drive system. Background Art

[0002] Electrification has become an inevitable trend in the development of the excavator industry. Most current electric excavators use an electric motor to replace the traditional internal combustion engine to drive the hydraulic pump to achieve power output. Although it can reduce the consumption of prime mover energy and emissions to a certain extent, due to the still use of a centralized hydraulic system, the energy transfer efficiency is low. The energy efficiency of the hydraulic system is only about 35%, and the recoverable energy generated during the operation of each actuator cannot be recovered. In addition, the centralized hydraulic transmission system is highly complex, and maintenance and fault troubleshooting are difficult. Therefore, the overall energy efficiency of electric excavators is still at a low level, making it difficult to meet the requirements of high power and high energy efficiency, greatly limiting the operating performance and endurance of excavators, and seriously restricting the green electrification transformation process of excavators. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an electric excavator based on a distributed electro-hydrostatic direct drive system to solve the above problems. The present invention adopts the following solutions: The present application provides an electric excavator based on a distributed electro-hydrostatic direct drive system, including a low-voltage control component, a high-voltage power supply component, a motor drive component, a slewing drive component, a motor pump component, an independent speed control valve component, a flow distribution valve component, and an actuator component; The high-voltage power supply component is electrically connected to the motor drive component to provide high-voltage power for the motor drive component; the motor drive component is electrically connected to the motor pump component and the slewing drive component to drive the motor pump component and the slewing drive component to operate; the low-voltage control component is electrically connected to the high-voltage power supply component, the motor drive component, the motor pump component, the independent speed control valve component, and the flow distribution valve component respectively to control the operation of the entire system. The motor pump component outputs high-pressure oil in three branches, and finally drives the actuator component to operate through the flow distribution valve component and the independent speed control valve component; the slewing drive component is used to drive the upper body of the excavator to achieve slewing motion; the flow distribution valve component is used to perform shunting, confluence, and oil circuit switching processing on the high-pressure oil in different branches provided by the motor pump component, and output it to the independent speed control valve component; the independent speed control valve component is used to control the high-pressure oil component of the actuator component to achieve the speed regulation control of the actuator component.

[0004] Preferably, the actuator assembly includes a travel hydraulic motor, a boom cylinder, an arm cylinder, and a bucket cylinder. The independent speed control valve assembly includes a boom speed control valve, a bucket speed control valve, an arm speed control valve, and a travel hydraulic motor speed control valve. The flow distribution valve assembly includes an arm flow distribution valve, a bucket flow distribution valve, and a travel hydraulic motor flow distribution valve. The motor pump assembly includes a boom motor pump, an arm motor pump, and a bucket motor pump; The inlets and outlets of the travel hydraulic motor, bucket cylinder, and arm cylinder are connected to the output ends of the corresponding independent speed control valves. The input end of the boom independent speed control valve is connected to the outlet of the boom motor pump. The arm speed control valve, bucket speed control valve, and travel motor speed control valve are respectively connected to the output ends of the corresponding flow distribution valves. The flow distribution valves are interconnected. The input ends of the arm flow distribution valve and the bucket flow distribution valve are respectively connected to the outlets of the arm motor pump and the bucket motor pump. The suction ports of the motor pumps are connected to the fuel tank.

[0005] Preferably, the boom motor pump is composed of a boom drive motor and a pump motor. The boom drive motor drives the pump motor through mechanical connection, and the boom cylinder is independently driven through the boom speed control valve. When the boom is lifted, the pump motor operates in the pump condition, outputting high-pressure oil to drive the boom cylinder to extend. When the boom is lowered, the pump motor operates in the motor condition, and the gravitational potential energy of the lowered boom is converted into hydraulic energy, which is finally absorbed by the boom drive motor in the form of electrical energy and stored in the high-voltage power supply assembly or consumed by other electrical units. The speed and direction of the boom cylinder are jointly adjusted by the output / output flow rate change of the boom motor pump and the spool opening change of the boom speed control valve.

[0006] Preferably, the arm flow distribution valve operates in an independent drive state. The pressure oil output by the arm motor pump all flows into the arm speed control valve through the arm flow distribution valve, realizing the independent drive of the arm cylinder; The speed of the arm cylinder in the independent drive state is jointly adjusted by the output flow rate change of the arm motor pump and the spool opening change of the arm speed control valve, and the direction change of its speed is realized by the arm speed control valve switching the oil circuit direction; The arm motor pump is composed of an arm drive motor and an open hydraulic pump. The output flow rate of the arm motor pump is jointly adjusted by the speed change of the arm drive motor and the displacement change of the open hydraulic pump.

[0007] Preferably, the bucket flow distribution valve operates in an independent drive state. The pressure oil output by the bucket motor pump all flows into the bucket speed control valve through the bucket flow distribution valve, realizing the independent drive of the bucket cylinder; The speed of the bucket cylinder in the independent drive state is jointly regulated by the change in the output flow of the bucket motor pump and the change in the spool opening of the bucket speed control valve, and the direction change of its speed is realized by the bucket speed control valve switching the oil circuit direction; The bucket motor pump consists of a bucket drive motor and an open hydraulic pump, and the output flow of the bucket motor pump is jointly regulated by the change in the rotation speed of the bucket drive motor and the change in the displacement of the open hydraulic pump.

[0008] Preferably, when the bucket cylinder and the arm cylinder face different flow operation requirements, by controlling the arm flow control valve and the bucket flow control valve of the flow distribution valve group, the flow generated by the bucket motor pump and the arm motor pump is distributed to achieve flow confluence and diversion. At this time, the flow of the bucket and arm cylinders comes from the flow output by the bucket and arm motor pumps at the same time, and the working speeds of the bucket and arm cylinders are jointly controlled by each motor pump, the flow distribution valve group, and the independent speed control valve.

[0009] Preferably, the flow distribution valve group cuts off the flow supply of the arm motor pump and the bucket motor pump to the arm cylinder and the bucket cylinder through the arm flow control valve and the bucket flow control valve, and supplies the flow to the travel motor speed control valve through the travel flow control valve, thereby driving the travel hydraulic motor to work; The speed of the travel motor is jointly regulated by the change in the output flow of the arm motor pump and the bucket motor pump and the change in the spool opening of the travel motor speed control valve, and the direction change of its speed is realized by the travel motor speed control valve switching the oil circuit direction.

[0010] Preferably, the slewing drive assembly uses a slewing motor to drive a reduction gear to slewing drive the upper structure of the excavator, and when slewing braking, the slewing motor provides a braking torque to feedback the slewing braking kinetic energy to the motor drive assembly and the high-voltage power supply assembly.

[0011] Preferably, the slewing drive assembly uses a slewing motor to drive a closed-circuit pump-controlled motor system to realize the slewing drive of the upper structure of the excavator.

[0012] Preferably, the high-voltage power supply assembly includes a battery pack group, a battery management system, a battery thermal management system, and a battery charging socket; The battery pack group provides high-voltage power for the whole machine system. The battery management system monitors key parameters such as the voltage, current, and temperature of the battery in real time to ensure that the battery operates within a safe range and prevent faults such as overcharging, over-discharging, and short circuits. The battery thermal management system keeps the battery working within the optimal temperature range during the operation of the excavator to ensure its performance and safety.

[0013] Preferably, the motor drive assembly includes a power distribution unit, a boom motor controller, an arm motor controller, a bucket motor controller, and a swing motor controller; The power distribution unit is electrically connected to each motor controller. Each motor controller controls the operating state of each drive motor by adjusting current, voltage, or frequency and electrical parameters, and further drives the bucket, arm, boom, and swing motors.

[0014] Preferably, the low-voltage control assembly includes a vehicle control unit, a human-machine interface, low-voltage accessories, a DC-DC converter, and a low-voltage battery; The DC-DC converter converts the high-voltage power supply into low-voltage electricity to supply power to the low-voltage battery and the low-voltage system; the vehicle control unit is connected to the human-machine interface, the high-voltage power supply assembly, and the motor drive assembly through a CAN bus to control the safe up and down high-voltage electricity of the high-voltage power supply assembly, and send target instructions to the motor drive assembly to control the operation of the drive motors; the vehicle control unit is electrically connected to each variable pump, pump motor, flow control valve assembly, and independent speed control valve assembly, and sends electrical signals to control each hydraulic component.

[0015] By adopting the above technical solutions, the present invention can achieve the following technical effects: 1. The electric excavator system based on the distributed electro-hydrostatic direct drive system of the present application can perform distributed independent drive on the boom, arm, bucket, and swing through multiple motor pumps and multiple speed control valve groups, breaking the traditional method of relying on a centralized multi-way valve for flow distribution, fundamentally solving the large amount of energy loss caused by the pressure coupling of multiple actuators, greatly improving the energy efficiency of the whole machine system, and realizing more efficient energy conversion and utilization.

[0016] 2. An independent drive motor with a pump motor is used to drive the boom to operate. When the boom is lowered, the gravitational potential energy of the boom lowering can be electrically recovered, and the gravitational potential energy during the lowering process is converted into electrical energy and stored in the high-voltage power supply system; an independent swing drive assembly is used to drive the upper body to swing. When the swing is braked, the kinetic energy of the upper body swing braking of the excavator can be converted into electrical energy and stored in the high-voltage power supply system, thereby further improving the energy utilization rate of the whole machine.

[0017] 3. Through the flow control valve assembly, when there is a large flow demand for the bucket and arm oil, the pressure oil provided by the bucket and arm variable pumps is combined and split to meet the rapid movement requirements of the arm and bucket; during the traveling operation, the pressure oil provided by the bucket and arm variable pumps is supplied to the traveling motor through an oil circuit switch to achieve traveling drive, realizing reasonable system flow reuse, thereby reducing the overall installed power of the distributed system. Description of the Drawings

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a schematic structural diagram of the distributed electro-hydrostatic direct drive electric excavator system of the present invention.

[0020] In the figure: 1 - low-voltage control component; 11 - vehicle control unit; 12 - human-machine interface; 13 - low-voltage accessories; 14 - lead-acid battery; 15 - DC-DC; 2 - high-voltage power supply component; 21 - battery management system; 22 - battery charging socket; 23 - battery pack group; 24 - battery thermal management system; 3 - motor drive component; 31 - high-voltage power distribution unit; 32 - slewing motor controller; 33 - pump motor controller; 34 - arm cylinder motor controller; 35 - bucket cylinder motor controller; 4 - slewing drive component; 5 - motor pump component; 51 - bucket cylinder motor pump; 52 - arm cylinder motor pump; 53 - boom cylinder motor pump; 511 - bucket variable pump drive motor; 512 - bucket variable pump; 521 - arm variable pump drive motor; 522 - arm variable pump; 531 - boom drive motor; 532 - pump motor; 6 - flow control valve component; 61 - travel hydraulic motor flow control valve; 62 - bucket flow control valve; 63 - arm flow control valve; 7 - independent speed control valve component; 71 - travel hydraulic motor speed control valve; 72 - bucket independent speed control valve; 73 - arm independent speed control valve; 74 - boom independent speed control valve; 8 - actuator component; 81 - travel hydraulic motor; 82 - travel hydraulic motor; 83 - bucket cylinder; 84 - arm cylinder; 85 - boom cylinder; 86 - boom cylinder. Specific embodiments

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0022] Embodiment The following are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the following embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention.

[0023] The present invention provides an electric excavator based on a distributed electro-hydrostatic direct drive system, including: a low-voltage control component 1; a vehicle control unit 11; a human-machine interface 12; low-voltage accessories 13; a lead-acid battery 14; a DC-DC 15; a high-voltage power supply component 2; a battery management system 21; a battery charging socket 22; a battery pack group 23; a battery thermal management system 24; a motor drive component 3; a high-voltage power distribution unit 31; a swing motor controller 32; a pump motor controller 33; a boom motor controller 34; a bucket motor controller 35; a swing drive component 4; a motor pump component 5; a bucket motor pump 51; a boom motor pump 52; a boom motor pump 53; a bucket variable pump drive motor 511; a bucket variable pump 512; a boom variable pump drive motor 521; a boom variable pump 522; a boom drive motor 531; a pump motor 532; a flow valve component 6; a travel hydraulic motor flow valve 61; a bucket flow valve 62; a boom flow valve 63; an independent speed control valve component 7; a travel hydraulic motor speed control valve 71; a bucket independent speed control valve 72; a boom independent speed control valve 73; a boom independent speed control valve 74; an actuator component 8; a travel hydraulic motor 81; a travel hydraulic motor 82; a bucket cylinder 83; a boom cylinder 84; a boom cylinder 85; a boom cylinder 86; Combined with the attached drawings of the specification Figure 1 In this embodiment, the bucket variable pump and the boom variable pump independently drive the bucket cylinder 83 and the boom cylinder 84 through the bucket flow valve 62 and the boom flow valve 63. Similarly, the pump motor 532 directly drives the boom cylinders 85 and 86 through the boom independent speed control valve 74.

[0024] Specifically, the inlet and outlet ports of the boom cylinders 85 and 86 are communicated with the boom independent speed control valve 74, and the pump motor 532 is used to independently drive the boom cylinders. When the excavator is performing the boom lowering operation, due to the action of gravity, the pump motor 532 operates in the reverse direction, converts the gravitational energy during the lowering process into electrical energy, and returns the energy to the battery pack group 23 through the boom drive motor 531, thereby improving the energy utilization rate.

[0025] As shown in the attached drawings of the specification Figure 1As shown, in this embodiment, the travel hydraulic motor flow control valve 61, the bucket flow control valve 62 and the arm flow control valve 63 are connected. When the bucket cylinder 83 is independently driven, the vehicle control unit 11 cuts off the oil circuit between the travel hydraulic motor flow control valve 61 and the arm flow control valve 63 by sending a control signal to the bucket flow control valve 62, so that the bucket variable pump 512 independently drives the bucket cylinder 83. When the arm cylinder 84 is independently driven, the vehicle control unit 11 sends a control signal to the arm flow control valve 63 to cut off the oil circuit between the bucket flow control valve 62, so that the arm variable pump 522 independently drives the arm cylinder 84.

[0026] As shown in the attached Figure 1 the specification, in this embodiment, when the bucket cylinder 83 faces a large-flow operation condition, the vehicle control unit 11 sends a control signal to the bucket flow control valve 62 through the CAN bus to cut off the oil circuit leading to the travel hydraulic motor flow control valve 61, and the vehicle control unit 11 sends a control signal to the arm flow control valve 63 to the oil circuit leading to the arm independent speed control valve 73. At this time, the flow rate of the bucket cylinder 83 can come from the combined flow rate of the bucket variable pump 512 and the arm variable pump 522. When the arm cylinder 84 faces a large-flow operation condition, the vehicle control unit 11 sends a control signal to the bucket flow control valve 62 to cut off the oil circuits leading to the travel hydraulic motor flow control valve 61 and the bucket independent speed control valve 72. At this time, the flow rate of the arm cylinder 84 can come from the combined flow rate of the bucket variable pump 512 and the arm variable pump 521.

[0027] As shown in the attached Figure 1 the specification, the travel hydraulic motors 81, 82 are connected to the travel hydraulic motor speed control valve 71, and the travel hydraulic motor speed control valve 71 is connected to the travel hydraulic motor flow control valve 61. When the excavator drives the travel hydraulic motor to work, the bucket flow control valve 62 cuts off the oil circuit leading to the bucket independent speed control valve 72, and the vehicle control unit 11 sends a control signal to the arm flow control valve 63 through the CAN bus to cut off the oil circuit leading to the arm independent speed control valve 73. At this time, the flow rate source for driving the travel hydraulic motor can be taken from the flow rate output by the bucket variable pump 512, or from the flow rate output by the arm variable pump 522. In addition, the flow rate for driving the travel hydraulic motor can also be taken from the combined flow rate output by the bucket variable pump 512 and the arm variable pump 522 at the same time.

[0028] As shown in the attached Figure 1As shown, the slewing drive assembly 4 is electrically connected to the slewing motor controller 32. This embodiment includes two slewing drive methods for the whole machine. Among them, in Method 1, the slewing drive assembly 4 is a slewing motor directly driving the whole machine to slew. The vehicle control unit 11 collects the slewing signal of the whole machine operation handle, sends a control signal to the slewing motor controller 32, and the slewing motor controller 32 sends control information to the slewing motor to drive the whole machine to slew. In Method 2, the slewing drive assembly is a closed-loop pump control system composed of a slewing motor pump and a slewing hydraulic motor. The slewing motor drives the variable pump to work. The pump adjusts the hydraulic flow and pressure. The state of the slewing body is real-time feedback through a closed-loop control system to adjust the operation of the motor and the pump to ensure the precise positioning and stable operation of the slewing system. The slewing motor is mechanically connected to the variable pump, and the variable pump communicates with the slewing hydraulic motor. The vehicle control unit 11 collects the slewing signal of the whole machine operation handle, and the vehicle control unit 11 sends slewing control information to the slewing motor controller 32 through the CAN bus. The slewing motor controller 32 sends control information to the slewing motor pump to directly drive the slewing hydraulic motor to work, thereby driving the whole machine to slew.

[0029] As shown in the attached drawings of the specification Figure 1 As shown, in this embodiment, the motor drive assembly includes a bucket motor controller 35, a boom motor controller 34, an arm motor controller 33, and a slewing motor controller 32; the output end of the motor controller is electrically connected to the motor, and is used to send the state information of each motor to the vehicle control unit 11, including motor speed, motor torque, and fault information, etc. At the same time, it receives the target control signal of the vehicle control unit 11 to drive the bucket motor controller 35, the boom motor controller 34, the arm motor controller 33, and the slewing drive motor controller 32 to work.

[0030] As shown in the attached drawings of the specification Figure 1As shown, in this embodiment, the high-voltage power supply assembly includes a battery thermal management system 24, a battery pack group 23, a battery charging socket 22, and a battery management system 21. The lead-acid battery 14 provides low-voltage power supply for the system; the input end and the output end of the battery management system 21 are electrically connected to the power battery and the driver respectively, and are used to monitor the state of the power battery and send it to the vehicle control unit. The output end of the battery thermal management system 24 is electrically connected to the battery management system, and communicates with the whole machine system through the CAN bus to monitor the temperature state of the power battery and send it to the vehicle control unit 11. The battery management system 21 and the battery thermal management system 24 perform state evaluation and health management by real-time monitoring parameters such as the voltage, temperature, and current of the battery cells. The high-voltage power supply assembly 2 is electrically connected to the motor drive assembly 3, and is used to provide drive electric energy for the motor drive assembly 3 and store and recover energy. The output end of the motor controller is electrically connected to the drive motor, and is used to send the motor state information to the controller, and at the same time receive the target control signal of the vehicle control unit 11 to drive the motor pump assembly 5 to work.

[0031] The above embodiments are only for illustrating the technical concept and characteristics of the present invention, and the purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

Claims

1. An electric excavator based on a distributed electrostatic hydraulic direct drive system, characterized in that: It includes a low-voltage control component, a high-voltage power supply component, a motor drive component, a rotary drive component, a motor pump component, an independent speed regulating valve component, a flow distribution valve component and an actuator component; The high-voltage power supply assembly is electrically connected to the motor drive assembly to provide high-voltage power to the motor drive assembly; the motor drive assembly is electrically connected to the motor pump assembly and the slewing drive assembly to drive the motor pump assembly and the slewing drive assembly to operate; the low-voltage control assembly is electrically connected to the high-voltage power supply assembly, the motor drive assembly, the motor pump assembly, the independent speed regulating valve assembly and the distribution valve assembly respectively to control the operation of the entire system, the motor pump assembly outputs high-pressure pressure oil of three branches, which finally drives the actuator assembly to operate through the distribution valve assembly and the independent speed regulating valve assembly; the slewing drive assembly is used to drive the upper body of the excavator to achieve slewing motion; the distribution valve assembly is used to divert, merge and switch the high-pressure pressure oil of different branches provided by the motor pump assembly, and output it to the independent speed regulating valve assembly; the independent speed regulating valve assembly is used to control the high-pressure pressure oil assembly of the actuator assembly to achieve the operating speed regulation control of the actuator assembly.

2. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 1 is characterized in that: The actuator assembly includes a travel hydraulic motor, a boom cylinder, a dipper rod cylinder and a bucket cylinder, the independent speed regulating valve assembly includes a boom speed regulating valve, a bucket speed regulating valve, a dipper rod speed regulating valve and a travel hydraulic motor speed regulating valve, the distribution valve assembly includes a dipper rod distribution valve, a bucket distribution valve and a travel hydraulic motor distribution valve, and the motor pump assembly includes a boom motor pump, a dipper rod motor pump and a bucket motor pump; The oil inlet and outlet ports of the travel hydraulic motor, bucket cylinder and arm cylinder are connected to the output ends of the corresponding independent speed regulating valves, the input end of the boom independent speed regulating valve is connected to the oil outlet port of the boom motor pump, the arm speed regulating valve, bucket speed regulating valve and travel motor speed regulating valve are respectively connected to the output ends of the corresponding distribution valves, the distribution valves are interconnected, the input ends of the arm distribution valve and the bucket distribution valve are respectively connected to the oil outlet ports of the arm motor pump and the bucket motor pump, and the oil suction ports of each motor pump are connected to the oil tank.

3. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2 is characterized in that: The boom motor pump is composed of a boom drive motor and a pump motor. The boom drive motor drives the pump motor through a mechanical connection, and independently drives the boom cylinder through the boom speed control valve; when the boom is lifted, the pump motor works in a pump condition, outputs high-pressure oil to drive the boom cylinder to extend, and when the boom is lowered, the pump motor works in a motor condition, and the gravitational potential energy of the boom lowering is converted into hydraulic energy, which is finally absorbed by the boom drive motor in the form of electrical energy and stored in the high-voltage power supply assembly for consumption by other power units; the speed and direction of the boom cylinder are jointly regulated by the output / output flow changes of the boom motor pump and the changes in the valve core opening of the boom speed control valve.

4. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2 is characterized in that: The boom distribution valve works in an independent driving state, and the pressure oil output by the boom motor pump flows into the boom speed regulating valve through the boom distribution valve to realize independent driving of the boom oil cylinder; The speed of the boom cylinder in the independent driving state is jointly adjusted by the output flow change of the boom motor pump and the change of the valve core opening of the boom speed regulating valve, and the direction switching of the speed is achieved by the boom speed regulating valve switching the oil circuit direction; The arm motor pump is composed of an arm drive motor and an open hydraulic pump. The output flow of the arm motor pump is adjusted by the rotation speed change of the arm drive motor and the displacement change of the open hydraulic pump.

5. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2 is characterized in that: The bucket flow distribution valve works in an independent driving state, and the pressure oil output by the bucket motor pump flows into the bucket speed regulating valve through the bucket flow distribution valve to realize independent driving of the bucket cylinder; The speed of the bucket cylinder in the independent driving state is jointly adjusted by the output flow change of the bucket motor pump and the change of the valve core opening of the bucket speed regulating valve, and the direction switching of the speed is achieved by the bucket speed regulating valve switching the oil circuit direction; The bucket motor pump is composed of a bucket drive motor and an open hydraulic pump. The output flow of the bucket motor pump is adjusted by the rotation speed change of the bucket drive motor and the displacement change of the open hydraulic pump.

6. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2 is characterized in that: When the bucket cylinder and the arm cylinder face different flow operation requirements, the flow generated by the bucket motor pump and the arm motor pump is distributed by controlling the arm distribution valve and the bucket distribution valve of the distribution valve group to achieve flow confluence or diversion. At this time, the flow of the bucket cylinder and the arm cylinder comes from the flow output simultaneously by the bucket motor pump and the arm motor pump. At this time, the working speed of the bucket cylinder and the arm cylinder is coordinated by each motor pump, the distribution valve group and the independent speed regulating valve.

7. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2 is characterized in that: The flow distribution valve group cuts off the flow supply of the arm motor pump and the bucket motor pump to the arm cylinder and the bucket cylinder through the arm flow distribution valve and the bucket flow distribution valve, and supplies the flow to the travel motor speed regulating valve through the travel flow distribution valve, thereby driving the travel hydraulic motor to travel; The speed of the travel motor is regulated by the output flow changes of the boom motor pump and the bucket motor pump and the valve core opening changes of the travel motor speed control valve, and the speed direction switching is achieved by switching the oil circuit direction of the travel motor speed control valve.

8. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2 is characterized in that: The slewing drive assembly uses a slewing motor to drive the reducer to slew the excavator's vehicle mounting mechanism, and during slewing braking, the slewing motor provides a braking torque to feed back the slewing braking kinetic energy to the motor drive assembly and the high-voltage power supply assembly.

9. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 8, characterized in that: The slewing drive assembly adopts a slewing motor to drive a closed pump-controlled motor system to realize slewing drive of the excavator's vehicle mounting mechanism.

10. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2, characterized in that: The high-voltage power supply assembly includes a battery pack, a battery management system, a battery thermal management system, and a battery charging socket; The battery pack provides high-voltage power for the entire system. The battery management system monitors battery parameters in real time to ensure that the battery operates within a safe range and prevents malfunctions. The battery thermal management system keeps the battery operating within an optimal temperature range during the operation of the excavator to ensure its performance and safety.

11. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2, characterized in that: The motor drive assembly includes a power distribution unit, a boom motor controller, a dipper arm motor controller, a bucket motor controller and a slewing motor controller; The power distribution unit is electrically connected to each motor controller, and each motor controller controls the operating state of each drive motor by adjusting the current, voltage or frequency and electrical parameters, and further drives the bucket, dipper arm, boom and rotary motor.

12. The electric excavator based on the distributed electrostatic hydraulic direct drive system according to claim 2, characterized in that: The low-voltage control assembly includes a vehicle control unit, a human-machine interface, low-voltage accessories, a DC-DC and a low-voltage battery; The DC-DC converts high-voltage power into low-voltage power to power the low-voltage battery and the low-voltage system; the vehicle control unit is connected to the human-machine interface, the high-voltage power supply assembly and the motor drive assembly through a CAN bus to control the safe up and down of the high-voltage power supply assembly, and sends target instructions to the motor drive assembly to control the operation of each drive motor; the vehicle control unit is electrically connected to each variable pump, pump motor, distribution valve assembly and independent speed control valve assembly, and sends electrical signals to control each hydraulic component.

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