A linear drive device based on electro-hydraulic composite drive

Abstract

The present invention discloses a linear drive device based on electro-hydraulic composite drive, comprising an energy recovery part, a mechanical transmission part, and an electric power part and a hydraulic power part connected to the mechanical transmission part, wherein the energy recovery part is connected to the electric power part and the hydraulic power part respectively; the mechanical transmission part comprises a first electric generator integrated machine, and the hydraulic power part comprises a hydraulic oil cylinder, and the piston of the hydraulic oil cylinder and the rotating shaft of the first electric generator integrated machine are respectively connected to the mechanical transmission part so that the piston of the hydraulic oil cylinder performs linear motion. Compared with the prior art, the hydraulic power part is used to control the movement of the piston of the hydraulic oil cylinder during the working process, and the electric power part is used to control the speed, displacement and accuracy of the piston of the hydraulic oil cylinder. Therefore, the present invention combines the advantages of high controllability of the electric power part and high transmission power density of the hydraulic power part, and has high control accuracy, strong driving ability and high power density.

Description

Technical Field

[0001] The invention relates to a driving device, and more particularly to a linear driving device based on electro-hydraulic composite driving. Background Art

[0002] The driving modes of traditional mechanical equipment mainly include pneumatic drive, motor drive and hydraulic drive. The working medium of pneumatic drive is air, which has the characteristics of low viscosity, small flow resistance and centralized air supply, but is limited by compressibility and has weak position control accuracy. Moreover, the rated working pressure level of the device using pneumatic drive is low and cannot match the pressure requirements of high-power equipment; motor drive has the advantages of simple structure, simple control and high precision, but when applied to high-power equipment, the size of the motor in the motor drive is large, especially when the motor is installed in the actuator, there is not only the problem of installation space limitation, but also additional external load is added to the actuator, which greatly affects the carrying capacity of the actuator; hydraulic drive has the advantages of high power density, fast dynamic response, high pressure level and strong overload capacity, and is widely used in high-power mechanical equipment, but hydraulic drive has the disadvantages of high energy consumption and low control accuracy.

[0003] In view of this, the inventor conducted in-depth research on this basis, and thus came up with this case. Summary of the invention

[0004] The purpose of the present invention is to provide a linear drive device based on electro-hydraulic composite drive with high control accuracy, strong driving ability and high power density.

[0005] To achieve the above object, the solution of the present invention is:

[0006] A linear drive device based on electro-hydraulic composite drive comprises an energy recovery part, a mechanical transmission part, and an electric power part and a hydraulic power part which are transmission-connected to the mechanical transmission part, wherein the energy recovery part is respectively connected to the electric power part and the hydraulic power part; the mechanical transmission part comprises a first electric generator, and the hydraulic power part comprises a hydraulic cylinder, wherein the piston of the hydraulic cylinder and the rotating shaft of the first electric generator are respectively transmission-connected to the mechanical transmission part so that the piston of the hydraulic cylinder performs linear motion.

[0007] The mechanical transmission part includes a connecting rod, a rotatable crank, and a sliding rod and a sliding groove that are slidably matched. The crank is transmission-connected to the rotating shaft of the first electric generator. One end of the connecting rod is hinged on the crank, and the other end of the connecting rod is transmission-connected to the sliding rod. The sliding rod and the sliding groove are slidably matched, and the first end of the sliding rod is connected to the piston of the hydraulic cylinder.

[0008] The electric power part also includes a first controller. The rotating shaft of the first electric generator is transmission-connected to the threaded sleeve or the crank. The first electric generator is bidirectionally electrically connected to the first controller.

[0009] The hydraulic power part includes a second controller, a second motor, a hydraulic pump, a one-way valve and a three-position four-way reversing valve; the second motor and the hydraulic pump are coaxially connected, the oil inlet of the hydraulic pump is connected to the oil tank, the oil outlet of the hydraulic pump is connected to the oil inlet of the one-way valve, the oil outlet of the one-way valve is connected to the P oil inlet of the three-position four-way reversing valve, the T oil return port of the three-position four-way reversing valve is connected to the oil tank, the A working port and the B working port of the three-position four-way reversing valve are respectively connected to the two rod chambers of the hydraulic cylinder one by one, and the piston of the hydraulic cylinder is driven and connected to the output part; wherein, the second motor is electrically connected to the second control in both directions.

[0010] The oil outlet of the hydraulic pump and the oil inlet of the one-way valve are also commonly connected to a relief valve, and the oil return port of the relief valve is connected to an oil tank.

[0011] The energy recovery unit includes an energy storage unit and an accumulator. The power supply ends of the first controller and the second controller are respectively electrically connected to the power supply ends of the energy storage unit. The accumulator is respectively connected to the oil outlet of the one-way valve and the P oil inlet of the three-position four-way reversing valve.

[0012] It also includes a whole machine controller and a control handle. The oil port of the accumulator is installed with a pressure sensor. The signal output end of the control handle is electrically connected to the signal input end of the whole machine controller. The sampling end of the pressure sensor is electrically connected to the signal input end of the whole machine controller. The whole machine controller is electrically connected to the first electric generator and the second motor in both directions.

[0013] The energy storage unit includes a charging and discharging battery.

[0014] The charging and discharging battery is a lithium battery.

[0015] After adopting the above structure, the present invention has the following beneficial effects:

[0016] 1. The present invention uses a first electric generator integrated machine to rigidly connect the rotating shaft and the piston of the hydraulic cylinder through a mechanical transmission part to realize electro-hydraulic composite drive, that is, during the working process, the hydraulic power part is used to control the movement of the piston of the hydraulic cylinder, and the electric power part is used to control the speed, displacement and accuracy of the piston of the hydraulic cylinder. Therefore, the present invention combines the advantages of high controllability of the electric power part and high transmission power density of the hydraulic power part, and has high control accuracy, strong driving ability and high power density.

[0017] 2. Energy is recovered under negative load conditions through the first electric generator and the accumulator. When the load moves slowly, the recovery mode is mainly electrical recovery and supplemented by hydraulic recovery. When the load moves quickly, the recovery mode is mainly hydraulic recovery and supplemented by electrical recovery. This improves the efficiency of energy recovery, and the recovered energy can be released directly, thereby improving energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention.

[0019] In the figure:

[0020] 11-a first electric generator integrated machine; 12-a first controller;

[0021] 21- hydraulic cylinder; 22- second controller;

[0022] 23-second motor; 24-hydraulic pump;

[0023] 25- one-way valve; 26- three-position four-way reversing valve;

[0024] 27-unloading valve; 31-control handle;

[0025] 32-machine controller; 41-energy storage unit;

[0026] 42- accumulator; 5- pressure sensor;

[0027] 6-Mechanical transmission part. DETAILED DESCRIPTION

[0028] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0029] A linear drive device based on electro-hydraulic composite drive, such as Figure 1 As shown, it includes an electric power part, a hydraulic power part, an energy recovery part, a mechanical transmission part and an execution part. The electric power part and the hydraulic transmission part are respectively connected to the mechanical transmission part, and the energy recovery part is respectively connected to the electric power part and the hydraulic power part; wherein, the electric power part includes a first electric generator integrated machine 11, and the hydraulic power part includes a hydraulic cylinder 21. The first electric generator integrated machine 11 and the hydraulic cylinder 21 are respectively connected to the mechanical transmission part so that the piston of the hydraulic cylinder 12 moves linearly.

[0030] In this embodiment, the output part of the mechanical transmission part is connected to a load, and the load may be a conventional engineering machine, such as a loader, a wood grabber or an excavator.

[0031] The above-mentioned mechanical transmission part 6 is essentially a mechanical coupling unit, which includes a carrier (not shown in the figure) and a transmission mechanism arranged in the carrier (not shown in the figure). The carrier can be a mounting member such as a box or a shell. The transmission mechanism includes a screw and a worm gear that meshes with each other. The screw can be rotatably mounted on the carrier, that is, the screw can be mounted on the carrier by conventional means such as bearings. A threaded sleeve is provided on the screw, and the external thread of the screw is adapted to the internal thread of the threaded sleeve. In addition, the threaded sleeve can be linearly slidably mounted on the carrier. The sliding structure of the threaded sleeve is that a sliding groove is provided in the portion of the threaded sleeve corresponding to the carrier, and a sliding block is provided on the carrier, and the sliding groove and the sliding block are slidably matched; the first electric generator 11 is installed on the carrier, and the rotating shaft of the first electric generator 11 is transmission-connected to the worm gear, and the two are connected in a conventional manner, such as a key connection, etc. The worm is arranged in a straight line direction, and the worm and the screw are transmission-connected in a conventional manner, and the two can be connected by an axis; wherein the threaded sleeve is transmission-connected to the piston of the hydraulic cylinder 21, and the screw and the piston of the hydraulic cylinder 21 are coaxially arranged. In this embodiment, the screw rod is an existing conventional ball screw rod.

[0032] When the first electric generator 11 is in the electric mode, the rotating shaft of the first electric generator 11 rotates to drive the worm wheel to rotate. The worm wheel and the worm are meshed, so that the worm rotates, thereby rotating the lead screw. Due to the spiral cooperation between the threaded sleeve and the lead screw, the threaded sleeve slides in a straight line under the action of the threaded sleeve.

[0033] When the first electric generator 11 is in the power generation mode, the movement of the piston of the hydraulic cylinder 21 enables the first electric generator 11 to obtain mechanical energy, convert the mechanical energy into electrical energy, and store it in the energy storage unit.

[0034] Furthermore, in the embodiment, the above-mentioned transmission mechanism can also adopt other transmission structures, for example, a crank-connecting rod mechanism, the crank-connecting rod mechanism includes a crank, a connecting rod, a sliding rod and a slide groove, the first electric generator 11 is installed in the carrier, the rotating shaft of the first electric generator 11 is transmission connected to the crank, one end of the connecting rod is hinged on the crank, and the first end of the connecting rod is located at a non-center position of the crank, the second end of the connecting rod is fixedly connected to one end of the sliding rod, wherein the connecting rod can be installed on the crank using a conventional rotating structure such as a rotating shaft or a short pin; the slide groove is provided on the carrier, the sliding rod is arranged along the direction of the slide groove, the sliding rod and the slide groove are slidably matched, and the two ends of the sliding rod respectively extend out of the corresponding ends of the slide groove, and the first end of the sliding rod is transmission connected to the free end of the piston of the hydraulic cylinder 21.

[0035] In addition, the transmission mechanism can also be a gear rack structure, that is, the transmission mechanism includes a gear and a rack that mesh with each other, the rotating shaft transmission of the first electric generator 11 is connected to the gear, and the rack can be installed on the carrier in a linear sliding manner, that is, a slide groove arranged along a straight line is provided on the carrier, the rack is slidably arranged in the slide groove, and the rack transmission is connected to the free end of the piston of the hydraulic cylinder 21.

[0036] The mechanical transmission part used in the present invention rigidly connects the first electric generator 11 and the piston of the hydraulic cylinder 21 to realize electro-hydraulic compound drive. That is to say, the hydraulic power part uses hydraulic pressure to passively control the movement of the piston of the hydraulic cylinder 21, and the first electric generator 11 actively controls the speed, displacement and accuracy of the piston of the hydraulic cylinder 21. In this way, the advantages of the high controllability of the motor and the high power density of the hydraulic power part are combined to meet the requirements of high precision and high power output.

[0037] The electric power part further includes a first controller 12 , the control end of the first controller 12 is electrically connected to the signal input end of the first electric generator 11 , so that the rotation speed of the first electric generator 11 can be controlled by the first controller 12 .

[0038] The above-mentioned hydraulic power part also includes a second controller 22, a second motor 23, a hydraulic pump 24, a one-way valve 25 and a three-position four-way reversing valve 26. The specific hydraulic circuit of the hydraulic power part is: the rotating shaft of the second motor 23 is connected to the rotating shaft of the hydraulic pump 24, and the second motor 23 and the hydraulic pump 24 are coaxially connected, the oil inlet of the hydraulic pump 24 is connected to the oil tank, the oil outlet of the hydraulic pump 24 is connected to the oil inlet of the one-way valve 25, the oil outlet of the one-way valve 25 is connected to the P oil inlet of the three-position four-way reversing valve 26, the T oil return port of the three-position four-way reversing valve 26 is connected to the oil tank, and the A working port of the three-position four-way reversing valve 26 is connected to the hydraulic chamber 1 of the hydraulic cylinder, and the B working port of the three-position four-way reversing valve 26 is connected to the hydraulic chamber 2 of the hydraulic cylinder 21. The control end of the second controller 22 is electrically connected to the driving end of the second motor 21 to control the start and stop of the second motor 21; that is, when the second motor 23 is working, the rotating shaft of the second motor 23 drives the hydraulic pump 24 to work, so as to suck oil from the oil tank, and the oil outlet of the hydraulic pump 24 pumps out high-pressure oil. In this embodiment, the three-position four-way reversing valve 26 is an electromagnetic reversing valve.

[0039] The energy recovery part includes an energy storage unit 41 and an accumulator 42. The oil port of the accumulator 42 is respectively connected to the oil outlet of the one-way valve 25 and the P oil inlet of the three-position four-way reversing valve, wherein the charging and discharging ends of the energy storage unit 41 are respectively electrically connected to the power supply ends of the first controller 12 and the second controller 22, and the first controller 12 and the second controller 22 can be powered by the energy storage unit 41. The energy storage unit 41 includes a rechargeable battery (not shown in the figure), and the charging and discharging battery can be a conventional charging and discharging battery, preferably a lithium battery; the accumulator 42 is a conventional hydraulic accumulator. Preferably, the oil outlet of the hydraulic pump 24 and the oil inlet of the one-way valve 25 are commonly connected to a unloading valve 27, and the oil return port of the unloading valve 27 is connected to the oil tank; when the oil pressure of the internal pressure oil of the accumulator 42 is higher than the opening pressure of the unloading valve 27, the unloading valve 27 opens, and the oil of the hydraulic pump 24 is directly unloaded through the unloading valve 27; when there is no pressure oil inside the accumulator 42 or the oil pressure is lower than the opening pressure of the unloading valve 27, the unloading valve 27 is closed, and the oil of the hydraulic pump 24 fills the accumulator 42 through the one-way valve 25.

[0040] The present invention uses a hydraulic power part, and adopts the accumulator 42 and the hydraulic pump 24 to supply oil together. At the same time, the unloading valve 27 is set, and the accumulator 42 is used to supply oil and the hydraulic pump 24 is used to unload during the hydraulic drive process, thereby ensuring that the present invention has no additional overflow loss and improving the energy efficiency of the present invention.

[0041] The present invention is also provided with a control handle 31 and a whole machine controller 32. The signal output end of the control handle 31 is electrically connected to the signal input end of the whole machine controller 32. The control handle 31 adopts the control handle in conventional engineering machinery to output a swing angle signal to the whole machine controller 32, that is, the whole machine controller 32 determines the control intention according to the control handle 31. This judgment method is a conventional judgment in this field, so it will not be described in detail.

[0042] Furthermore, the signal output end of the whole machine controller 32 is electrically connected to the signal input end of the first controller 12, and the speed, torque and angle of rotation of the first electric generator 11 are controlled by the whole machine controller 32, and the movement speed, output force and displacement of the piston of the hydraulic cylinder 21 are controlled by the above-mentioned mechanical transmission part; the signal output end of the whole machine controller 32 is also electrically connected to the signal input end of the second controller 22, so that the whole machine controller 32 outputs a control signal to the second controller 22 according to parameters such as the speed of the first electric generator 11 and the signal of the control handle 31, and the second controller 22 controls the parameters of the second motor 23, thereby controlling the output flow and pressure of the hydraulic pump 24.

[0043] Furthermore, a pressure sensor 5 is installed at the oil port of the accumulator 42 , and a sampling end of the pressure sensor 5 is electrically connected to a signal input end of the whole machine controller 32 , so as to detect the oil port pressure of the accumulator 42 through the pressure sensor 5 .

[0044] Furthermore, the signal output terminal of the whole machine controller 32 is electrically connected to the electromagnetic terminal of the three-position four-way reversing valve 26 , so as to realize the on-off connection with the hydraulic cylinder 21 by switching on and off the three-position four-way reversing valve 26 .

[0045] In the present invention, the driving requirements of different loads such as light and heavy loads are met by actively controlling the motoring mode and the power generation mode of the first motor-generator integrated machine 11. The specific working process is as follows:

[0046] 1. When the load is light, the linear drive device is started, and the whole machine controller 32 operates according to the state of the control handle 12, controls the second motor 23 to drive the hydraulic pump 24 to suck oil from the oil tank, and pumps out high-pressure oil from the oil outlet of the hydraulic pump 24, and controls the three-position four-way reversing valve 26 according to the moving direction of the load. At the same time, the first electric generator 11 works in the power generation mode to recover part of the energy transmitted by the piston of the hydraulic cylinder 21.

[0047] 2. When the load is heavy, the linear drive device is started, and the whole machine controller 32 operates according to the state of the control handle 12, controls the second motor 23 to drive the hydraulic pump 24 to suck oil from the oil tank, and pumps out high-pressure oil from the oil outlet of the hydraulic pump 24, and controls the three-position four-way reversing valve 26 according to the moving direction of the load. At the same time, the first electric generator 11 works in the electric mode so as to push the load together with the piston of the hydraulic cylinder 21.

[0048] In this embodiment, the lightness or heaviness of the load is set according to actual working conditions and is not limited here.

[0049] In the above process, the whole machine controller 32 obtains the pressure value of the accumulator 42 through the pressure sensor. When the whole machine controller 32 detects that the pressure value of the pressure sensor reaches the set target threshold, that is, when the oil port pressure of the accumulator 42 reaches the set target threshold, the whole machine controller 32 outputs a control instruction to the second controller 22, and the second controller 22 controls the second motor 23 to stop working, thereby stopping the hydraulic pump 24, and then performs the following operations according to the two working conditions of the load.

[0050] For the convenience of description, Figure 1 The left side of the left hand side is the left side, the right hand side is the right side, the two working conditions of the load are positive load and negative load, the negative load here means that the speed direction of the load is the same as the force direction, and the positive load means that the speed direction of the load is opposite to the force direction. In this embodiment, the above-mentioned linear motion is left-right motion.

[0051] 1. Negative load conditions:

[0052] When the load moves to the left (i.e., the load force is to the left), the speed direction of the load is left, and the piston of the hydraulic cylinder 21 needs to suppress the load force and extend to the left. The pressure of the left chamber of the hydraulic cylinder 21 is controlled to achieve the load moving slowly to the left at the target speed.

[0053] The specific process is as follows: the whole machine controller 32 controls the three-position four-way reversing valve 26 to work in the right position. At this time, the P oil inlet and the A working port of the three-position four-way reversing valve 26 are connected, and the B working port and the T oil return port are connected. The accumulator 42 outputs high-pressure liquid oil through the P oil inlet and the A working port in turn, and flows into the left chamber of the hydraulic cylinder 21 to drive the piston of the hydraulic cylinder 21 to offset most of the load force. At the same time, when the whole machine controller 32 detects that the target speed of the piston of the hydraulic cylinder 21 is small, that is, when the load moves slowly to the left, the whole machine controller 32 outputs a command to the first controller 12 to make the first electric generator 11 work in the power generation mode. The whole machine controller 32 controls The rotation speed of the first electric generator 11 controls the speed of the piston of the hydraulic cylinder 21 through the coupling of the mechanical transmission part 6, so as to balance the other part of the load force. At the same time, this part of the load force will drive the first electric generator 11 to generate electrical energy and store it in the energy storage unit, that is, electrical recovery; at the same time, the whole machine controller 32 controls the rotation speed of the second motor 23 to zero, that is, controls the rotation speed of the hydraulic pump 24 to zero, and the whole machine controller 32 controls the opening area of ​​the three-position four-way reversing valve 26 to match the load force and the pressure of the accumulator 42, so that the hydraulic oil in the left chamber of the hydraulic cylinder 21 flows back to the accumulator 41 for storage, thereby realizing hydraulic energy recovery.

[0054] In addition, when the whole machine controller 32 detects that the target speed of the piston of the hydraulic cylinder 21 is relatively large, that is, when the load moves rapidly to the left, the whole machine controller 32 outputs a control instruction to the first controller 12, and the first controller 12 controls the first electric generator 11 to be in the power generation mode to control the rotation speed of the first electric generator 11 so as to recover the kinetic energy and / or potential energy generated by the load. At the same time, the whole machine controller 32 outputs a control instruction to the second controller 22, and the second controller 22 controls the rotation speed of the second motor 23 so that the rotation speed of the hydraulic pump 23 is zero. At the same time, the whole machine controller 32 controls the opening area of ​​the three-position four-way reversing valve 26 to match the load force and the pressure of the accumulator 42, so that the accumulator 42 recovers a large amount of oil, that is, a large amount of energy is recovered through the accumulator 42, thereby realizing a recovery mode with hydraulic recovery as the main and electrical recovery as the auxiliary.

[0055] Similarly, when the load moves to the right (i.e., the load force is to the right), the speed direction of the load is to the right, and the piston of the hydraulic cylinder 21 needs to suppress the load force and extend to the right, so as to control the right chamber pressure of the hydraulic cylinder 21 so that the load moves slowly to the right at the target speed. The above-mentioned corresponding working principle is also adopted to adopt a recovery mode in which electrical recovery is mainly and hydraulic recovery is auxiliary when the load moves slowly, and a recovery mode in which hydraulic recovery is mainly and electrical recovery is auxiliary when the load moves quickly.

[0056] It should be noted that the whole machine controller 32 determines the displacement of the control handle 31, that is, the target speed of the piston of the hydraulic cylinder 31, according to the swing angle signal of the control handle 12. When the target speed of the piston of the hydraulic cylinder 31 is large, it can be judged that the load is moving quickly. When the target speed of the piston of the hydraulic cylinder 31 is small, it can be judged that the load is moving slowly.

[0057] It should be noted that the speed of the load movement is determined based on actual conditions and is not limited here.

[0058] 2. Positive load condition:

[0059] When the load moves to the left, the speed direction of the load is right, and the hydraulic cylinder 21 needs to overcome the load force and extend to the right to overcome the load force and move to the right;

[0060] The specific process is: the whole machine controller 32 controls the three-position four-way reversing valve 26 to work in the right position. At this time, the P oil inlet and the A working port of the three-position four-way reversing valve 26 are connected, and the B working port and the T oil return port are connected. The accumulator 42 outputs high-pressure liquid oil through the P oil inlet and the A working port in turn, and flows into the left chamber of the hydraulic cylinder 21 to drive the piston of the hydraulic cylinder 21 to offset most of the load force. At the same time, the whole machine controller 32 outputs instructions to the first controller 12. The first controller 12 controls the first electric generator 11 to be in electric mode and controls the speed of the first electric generator 11 to control the speed of the piston of the hydraulic cylinder 21 through the mechanical transmission part 6 to balance the other part of the load force.

[0061] Similarly, when the load moves to the right and the speed direction of the load is left, the hydraulic cylinder 21 needs to overcome the load force and extend to the left, the whole machine controller 32 controls the three-position four-way reversing valve 26 to work in the left position. At this time, the P oil inlet and the B working port of the three-position four-way reversing valve 26 are connected, and the A working port and the T oil return port are connected. The accumulator 42 outputs high-pressure oil through the P oil inlet and the B working port of the three-position four-way reversing valve 26 in turn, and flows into the right chamber of the hydraulic cylinder 21 to drive the piston of the hydraulic cylinder 21 to move to the left to balance most of the load force. At the same time, the whole machine controller 32 obtains the target speed of the piston of the hydraulic cylinder 21 according to the swing angle signal input by the control handle 31, and the whole machine controller 32 outputs a control signal to the first controller 11. The first controller 11 controls the first electric generator 11 to work in the electric mode and controls the speed of the first electric generator 11. The speed of the piston of the hydraulic cylinder 21 is controlled through the above-mentioned mechanical transmission part 6 to balance the other part of the load force.

[0062] In the present invention, the power generation mode and accumulator in the first electric generator 11 are used to recover energy for negative load conditions. When the load moves slowly, a recovery mode with electrical recovery as the main and hydraulic recovery as the auxiliary is adopted; when the load moves quickly, a recovery mode with hydraulic recovery as the main and electrical recovery as the auxiliary is adopted. In this way, energy recovery is carried out according to the actual load situation to improve the efficiency of energy recovery. At the same time, the recovered energy can be fully released to improve the energy utilization rate.

[0063] The above description is only a preferred embodiment of the present embodiment, and all equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A linear drive device based on electro-hydraulic composite drive, characterized in that: It includes an energy recovery part, a mechanical transmission part, and an electric power part and a hydraulic power part that are transmission-connected to the mechanical transmission part, the energy recovery part is respectively connected to the electric power part and the hydraulic power part; the mechanical transmission part includes a first electric generator, the hydraulic power part includes a hydraulic cylinder, the piston of the hydraulic cylinder and the rotating shaft of the first electric generator are respectively transmission-connected to the mechanical transmission part so that the piston of the hydraulic cylinder performs linear motion, and the mechanical transmission part includes a carrier and a transmission mechanism arranged in the carrier.

2. The linear drive device based on electro-hydraulic composite drive according to claim 1, characterized in that: The transmission mechanism includes a connecting rod, a rotatable crank, and a sliding rod and a sliding groove that slidably cooperate. The crank is transmission-connected to the rotating shaft of the first electric generator. One end of the connecting rod is hinged on the crank, and the other end of the connecting rod is transmission-connected to the sliding rod. The sliding rod and the sliding groove slidably cooperate, and the first end of the sliding rod is connected to the piston of the hydraulic cylinder.

3. The linear drive device based on electro-hydraulic composite drive according to claim 2, characterized in that: The electric power part also includes a first controller, the rotating shaft of the first electric generator is transmission-connected to the crank, and the first electric generator is bidirectionally electrically connected to the first controller.

4. The linear drive device based on electro-hydraulic composite drive according to claim 3, characterized in that: The hydraulic power part includes a second controller, a second motor, a hydraulic pump, a one-way valve and a three-position four-way reversing valve; the second motor and the hydraulic pump are coaxially connected, the oil inlet of the hydraulic pump is connected to the oil tank, the oil outlet of the hydraulic pump is connected to the oil inlet of the one-way valve, the oil outlet of the one-way valve is connected to the P oil inlet of the three-position four-way reversing valve, the T oil return port of the three-position four-way reversing valve is connected to the oil tank, the A working port and the B working port of the three-position four-way reversing valve are respectively connected to the two rod chambers of the hydraulic cylinder one by one, and the piston transmission of the hydraulic cylinder is connected to the output part of the mechanical transmission part; wherein, the second motor is electrically connected to the second control bidirectionally.

5. The linear drive device based on electro-hydraulic composite drive according to claim 4, characterized in that: The oil outlet of the hydraulic pump and the oil inlet of the one-way valve are also commonly connected to a relief valve, and the oil return port of the relief valve is connected to an oil tank.

6. The linear drive device based on electro-hydraulic composite drive according to claim 4, characterized in that: The energy recovery part includes an energy storage unit and an accumulator. The power supply ends of the first controller and the second controller are respectively electrically connected to the power supply ends of the energy storage unit. The accumulator is respectively connected to the oil outlet of the one-way valve and the P oil inlet of the three-position four-way reversing valve.

7. The linear drive device based on electro-hydraulic composite drive according to claim 6, characterized in that: It also includes a whole machine controller and a control handle. The oil port of the accumulator is installed with a pressure sensor. The signal output end of the control handle is electrically connected to the signal input end of the whole machine controller. The sampling end of the pressure sensor is electrically connected to the signal input end of the whole machine controller. The whole machine controller is electrically connected to the first electric generator and the second motor in both directions.

8. The linear drive device based on electro-hydraulic composite drive according to claim 7, characterized in that: The energy storage unit includes a charging and discharging battery.

9. The linear drive device based on electro-hydraulic composite drive according to claim 8, characterized in that: The charging and discharging battery is a lithium battery.

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