A rotary drive device based on electro-hydraulic compound drive

Abstract

The present invention discloses a rotary drive device based on electro-hydraulic composite drive, comprising an electric generator, a hydraulic pump / motor, a hydraulic circuit and a rotating part, wherein the first end of the rotating shaft of the electric generator is transmission-connected to the rotating part, the second end of the rotating shaft of the electric generator is transmission-connected to the rotating shaft of the hydraulic pump / motor, and the hydraulic pump / motor is provided with a hydraulic chamber 1 and a hydraulic chamber 2, and both the hydraulic chamber 1 and the hydraulic chamber 2 are connected to the hydraulic circuit. Compared with the prior art, the present invention combines the advantages of high-precision control of the electric motor and high transmission power of the hydraulic pressure, and realizes the high control precision, strong driving ability and high power density of the present invention.

Description

Technical Field

[0001] The present invention relates to a driving device, and more particularly to a rotary driving device based on an electro-hydraulic composite drive. 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 connected to the rotating part, there is not only the problem of connection space limitation, but also an additional external load is added to the rotating part, which greatly affects the carrying capacity of the rotating part; 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 object of the present invention is to provide a rotary drive device based on electro-hydraulic composite drive with high control accuracy, strong driving capability and high power density.

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

[0006] A rotary drive device based on electro-hydraulic composite drive comprises an electric generator, a hydraulic pump / motor, a hydraulic circuit and a rotating part, wherein the first end of the rotating shaft of the electric generator is transmission-connected to the rotating part, the second end of the rotating shaft of the electric generator is transmission-connected to the rotating shaft of the hydraulic pump / motor, the hydraulic pump / motor is provided with a hydraulic chamber 1 and a hydraulic chamber 2, and both the hydraulic chamber 1 and the hydraulic chamber 2 are communicated with the hydraulic circuit.

[0007] The hydraulic circuit includes an electric motor, a hydraulic pump, a one-way valve and a three-position four-way reversing valve. The output shaft of the electric motor is connected to the rotating shaft of the hydraulic pump. 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 inlet 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 hydraulic chamber one and the hydraulic chamber two in a one-to-one correspondence.

[0008] The hydraulic circuit also includes two oil-replenishing one-way valves and two safety valves, the oil inlets of the two oil-replenishing one-way valves and the oil outlets of the two safety valves are connected to the oil tank, the oil outlet of one of the oil-replenishing one-way valves and the oil inlet of the safety valve are respectively connected to the pipeline between the A working port of the three-position four-way reversing valve and the hydraulic chamber one, and the oil outlet of the other oil-replenishing one-way valve and the oil inlet of the safety valve are respectively connected to the pipeline between the B working port of the three-position four-way reversing valve and the hydraulic chamber two.

[0009] The hydraulic circuit also includes a safety valve three, the oil outlet of the safety valve three is connected to the oil tank, and the oil inlet of the safety valve three is connected to the pipeline between the oil inlet of the one-way valve and the oil outlet of the hydraulic pump.

[0010] It also includes a control system, which includes a control handle, a whole machine controller, a first controller and a second controller. The signal output end of the control handle is connected to the signal input end of the whole machine controller, and the whole machine controller is bidirectionally electrically connected to the first controller and the second controller respectively; the signal output end of the first controller is connected to the control end of the electric motor, the signal output end of the second controller is connected to the control end of the electric generator, and the signal output end of the whole machine controller is respectively connected to the control end of the hydraulic pump / motor and the electromagnetic end of the three-position four-way reversing valve.

[0011] It also includes an energy recovery unit, which includes an accumulator and an electric energy storage unit. The oil port of the accumulator is connected to the pipeline between the oil outlet of the one-way valve and the P oil inlet of the three-position four-way reversing valve; the power supply end of the electric energy storage unit is respectively connected to the power supply end of the first controller and the second controller.

[0012] A pressure sensor is installed at the oil port of the accumulator, and a sampling end of the pressure sensor is connected to a signal input end of the whole machine controller.

[0013] The electrical energy storage unit includes a rechargeable battery.

[0014] After adopting the above structure, the present invention has the following beneficial effects:

[0015] 1. During the process of driving the rotating part to rotate, the electric generator works in the motor mode, and the hydraulic pump / motor works in the motor mode. The electric generator and the hydraulic pump / motor are directly coaxially connected, so that the electric generator and the hydraulic pump / motor jointly drive the rotating part; in this way, the present invention combines the advantages of high-precision control of the electric motor and high transmission power of the hydraulic pressure, and realizes the high control accuracy, strong driving ability and high power density of the present invention.

[0016] 2. In the present invention, during the braking process, the electric generator works in the generator mode and the hydraulic pump / motor works in the pump mode. When the load is braked slowly, the electric generator controls its deceleration to generate the main braking force, and at the same time controls the opening area of ​​the hydraulic pump / motor to control the displacement, thereby realizing a mode in which electrical recovery is the main mode and hydraulic recovery is the auxiliary mode. When the load is braked quickly, the opening area of ​​the hydraulic pump / motor is controlled to increase the displacement to recover the braking kinetic energy into the accumulator, thereby generating the main braking force. At the same time, the output power of the electric generator is relatively small, and the electric generator is controlled to decelerate to generate a small amount of braking force, thereby realizing a mode in which hydraulic recovery is the main mode and electrical recovery is the auxiliary mode. In this way, high-efficiency recovery can be achieved through different braking conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] In the figure:

[0019] 10-electric generator; 20-hydraulic pump / motor;

[0020] 31-electric motor; 32-hydraulic pump;

[0021] 33- one-way valve; 34- three-position four-way reversing valve;

[0022] 361-Oil replenishment check valve 1;

[0023] 362-Oil replenishment check valve 2; 371-Safety valve 1;

[0024] 372-Safety valve 2; 38-Safety valve 3;

[0025] 41-control handle; 42-machine controller;

[0026] 43-first controller; 44-second controller;

[0027] 51- accumulator; 52- electric energy storage unit;

[0028] 53-Pressure sensor. DETAILED DESCRIPTION

[0029] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments.

[0030] A linear drive device based on electro-hydraulic composite drive, such as Figure 1As shown, it includes an electric generator 10, a hydraulic pump / motor 20, a hydraulic circuit and a rotating part. Both ends of the rotating shaft of the electric generator 10 extend to the outside. In this embodiment, the double rotating shafts correspond to the first end and the second end of the rotating shaft respectively. The first end of the rotating shaft of the electric generator 10 is transmission-connected to the rotating part, and the second end of the rotating shaft of the electric generator 10 is transmission-connected to the rotating shaft of the hydraulic pump / motor 20; the hydraulic chamber 1 and the hydraulic chamber 2 of the hydraulic pump / motor 20 are both connected to the hydraulic circuit.

[0031] In the present invention, the load may be a conventional engineering machinery, such as a loader, a wood grabber or an excavator; the rotating part may be a loading platform of the load, or a connecting device between the load and the drive shaft thereon, such as a slewing table of a slewing system in an excavator.

[0032] The first end of the rotating shaft of the above-mentioned electric generator 10 is coaxially connected to the rotating part, and the connection between the two adopts an existing conventional connection structure, such as a flange connection or a key connection; the second end of the rotating shaft of the electric generator 10 is coaxially connected to the rotating shaft of the hydraulic pump / motor 20, and the two can be connected by a coupling.

[0033] In this way, when the electric generator 10 works in the motor mode and the hydraulic pump / motor 20 works in the motor mode, the second end of the rotating shaft of the electric generator 10 rotates, and at the same time, the rotating shaft of the hydraulic pump / motor 20 rotates, so that the second end of the rotating shaft of the electric generator 10 and the rotating shaft of the hydraulic pump / motor 20 rotate synchronously in the same direction, thereby causing the first end of the rotating shaft of the electric generator 10 to rotate, and then causing the load to rotate.

[0034] When the electric generator 10 operates in generator mode and the hydraulic pump / motor 20 operates in pump mode, the rotation direction of the first end of the rotating shaft of the electric generator 10 is opposite to the rotation direction of the rotating load, and the rotating second end of the electric generator 10 is also opposite to the rotation direction of the load, and drives the rotating shaft of the hydraulic pump / motor 20 to rotate in the opposite direction.

[0035] The above-mentioned hydraulic circuit includes an electric motor 31, a hydraulic pump 32, a one-way valve 33 and a three-position four-way reversing valve 34. The specific hydraulic circuit is as follows: the output shaft of the electric motor 31 is connected to the rotating shaft of the hydraulic pump 32, the oil inlet of the oil pump 32 is connected to the oil tank, and the oil outlet of the hydraulic pump 32 is connected to the oil inlet of the one-way valve 33, the oil outlet of the one-way valve 33 is connected to the P oil inlet of the three-position four-way reversing valve 34, the T oil return port of the three-position four-way reversing valve 34 is connected to the oil tank, and the A working port and the B working port of the three-position four-way reversing valve 34 are respectively connected to the hydraulic chamber 1 and the hydraulic chamber 2 of the hydraulic pump / motor 20 in a one-to-one correspondence. In this embodiment, the three-position four-way reversing valve 34 is an existing conventional electromagnetic reversing valve.

[0036] Furthermore, the hydraulic circuit also includes an oil replenishing check valve 1 361, an oil replenishing check valve 2 362, a safety valve 1 371 and a safety valve 2 372. The oil inlets of the oil replenishing check valve 1 361 and the oil replenishing check valve 2 362 are both connected to the oil tank, and the oil outlets of the safety valve 1 371 and the safety valve 2 372 are both connected to the oil tank. The oil outlet of the oil replenishing check valve 1 361 and the oil inlet of the safety valve 1 371 are respectively connected to the pipeline between the A working port of the three-position four-way reversing valve 34 and the hydraulic chamber 1 of the hydraulic pump / motor 20, and the oil outlet of the oil replenishing check valve 2 362 and the oil inlet of the safety valve 2 372 are respectively connected to the pipeline between the B working port of the three-position four-way reversing valve 34 and the hydraulic chamber 2 of the hydraulic pump / motor 20.

[0037] Furthermore, the hydraulic circuit also includes a safety valve three 38, the oil outlet of the safety valve three 38 is connected to the oil tank, and the oil inlet of the safety valve three 38 is connected to the pipeline between the oil inlet of the one-way valve 33 and the oil outlet of the hydraulic pump 32.

[0038] The present invention also includes a control system, which includes a control handle 41, a whole machine controller 42, a first controller 43 and a second controller 44; the signal output end of the control handle 41 is electrically connected to the signal input end of the whole machine controller 42, and the whole machine controller 42 obtains the target speed of the above-mentioned rotating part according to the input signal of the control handle 41, wherein the above-mentioned operation is a conventional operation of the engineering machinery, so it is not described in detail; the whole machine controller 42 is bidirectionally electrically connected to the first controller 43, and the signal output end of the first controller 43 is electrically connected to the control end of the motor 31, so that the whole machine controller 42 transmits the control instruction to the first controller 43 according to the target speed of the rotating part, and the first controller 43 controls the speed of the motor 31; the whole machine controller 42 is bidirectionally electrically connected to the second controller 44, and the signal output end of the second controller 44 is electrically connected to the control end of the electric generator 10, and the whole machine controller 42 transmits the control instruction to the second controller 44 according to the target speed of the rotating part, and the second controller 44 controls the electric mode and the power generation mode of the electric generator 10, and controls the speed of the electric generator 10 in the electric mode and the speed of the electric generator 10 in the power generation mode. In addition, the signal output end of the whole machine controller 42 is also electrically connected to the solenoid end of the three-position four-way reversing valve to control the pipeline of the hydraulic circuit; and the signal output end of the whole machine controller 42 is also electrically connected to the control end of the hydraulic pump / motor 20 to control the pump mode and motor mode of the hydraulic pump / motor 20, and control its speed in the motor mode.

[0039] The present invention also includes an energy recovery unit, which includes an accumulator 51 and an electric energy storage unit 52, that is, the present invention has two energy recovery modes, electrical recovery and hydraulic recovery; the oil port of the accumulator 51 is connected to the pipeline between the oil outlet of the one-way valve 33 and the P oil inlet of the three-position four-way reversing valve 34, and the power supply end of the electric energy storage unit 52 is electrically connected to the power supply end of the first controller 43 and the second controller 44 respectively. Preferably, a pressure sensor 53 is installed at the position of the oil port of the accumulator 51, and the sampling end of the pressure sensor 53 is electrically connected to the signal input end of the whole machine controller 42, so as to transmit the data collected by the pressure sensor 53 to the whole machine controller 42. In this embodiment, the electric energy storage unit 52 includes a conventional charging and discharging battery, preferably, the charging and discharging battery is a lithium battery, that is, the charging and discharging end (i.e., the power supply end) of the charging and discharging battery is electrically connected to the charging and discharging end of the whole machine controller 42.

[0040] The specific working process of the present invention is:

[0041] 1. During startup, the whole machine controller 42 determines the target speed of the load according to the input signal of the control handle 41, and then controls the electric generator 10 to operate in the motor mode through the second controller 44, so that the first end of the rotating shaft of the electric generator 10 rotates clockwise, and controls the rotation speed of the electric generator 10. At the same time, the whole machine controller 42 controls the hydraulic pump / motor 20 to operate in the motor mode, so that the rotating shaft of the hydraulic pump / motor 20 and the second end of the rotating shaft of the electric generator 10 rotate clockwise synchronously, so that the hydraulic pump / motor 20 outputs a large torque to the electric generator 10, thereby driving the load to rotate clockwise, so that the present invention is started. During this process, the whole machine controller 42 controls the speed of the motor 31 through the first controller 43. At this time, the three-position four-way reversing valve 34 works in the left position. The left position refers to the connection between the P oil inlet and the A working port, and the connection between the B working port and the T oil return port. The hydraulic oil in the oil tank flows into the hydraulic chamber 1 of the hydraulic pump / motor 20. At the same time, the whole machine controller 42 obtains the pressure data transmitted by the pressure sensor 53 in real time, so that the oil port pressure of the accumulator 51 is maintained at the set target threshold. When the oil port pressure of the accumulator 51 reaches the target threshold, the motor 31 stops working, so that the accumulator 51 can be used as a power source to reduce overflow loss, thereby improving energy efficiency. Among them, the setting of the target threshold is set in the first controller 43 according to the actual situation of the accumulator 51 and the hydraulic circuit.

[0042] In the process of driving the load, the electric generator 10 works in the motor mode to achieve normal working speed regulation, and the hydraulic pump / motor 20 works in the motor mode to generate the target large torque through the displacement of the hydraulic pump / motor 20. In this way, the torque direction provided by the hydraulic pump / motor 20 is the same as that of the electric generator 10, which means that the action of the hydraulic pump / motor 20 reduces the load that the electric generator 10 needs to drive, reduces the interference of the load driven by the electric generator 10, and increases the acceleration of the rotating part to quickly reach the target speed. In this way, the present invention combines the advantages of high-precision control of the electric motor and high transmission power of the hydraulic pump / motor, and realizes the high control accuracy, strong driving ability and high power density of the present invention.

[0043] 2. When the load reaches the target speed, the whole machine controller 42 controls the speed of the electric generator 10 in the motor mode through the second controller 43. At the same time, the whole machine controller 42 controls the displacement of the hydraulic pump / motor 20, which is the minimum displacement to ensure the leakage of the hydraulic circuit. At this time, the present invention uses the electric generator 10 as the main driving unit.

[0044] 3. After the load reaches the target speed and the weight of the load becomes heavier, the whole machine controller 42 controls the speed of the electric generator 10. At the same time, the whole machine controller 42 controls the displacement of the hydraulic pump / motor 20 according to the pressure data detected by the pressure sensor 53, that is, the oil port pressure of the accumulator 51, to generate the target torque. The hydraulic pump / motor 20 and the electric generator 20 drive the load in combination.

[0045] 4. During the braking process, the load braking is divided into two situations: slow braking and fast braking. The following describes these two situations in detail. The judgment of slow braking and fast braking is made by the whole machine controller 42 through the output signal of the control handle 41. This operation is a conventional operation in existing engineering machinery, so it will not be described in detail.

[0046] 1. During load braking, when the control handle 51 returns to the middle position, it is judged as slow braking. The braking control of the electric generator 10 is mainly used to control the electric generator in the generator mode and control the speed of the electric generator 10 to decelerate to generate braking force, that is, the electric generator 10 generates a torque opposite to the torque direction of the load; at the same time, the hydraulic pump / motor 20 is controlled to work in the pump mode, so that the hydraulic pump / motor 20 generates a braking force in the same direction as the electric generator 10, and when the speed of the electric generator 10 is lower than the set speed threshold, the whole machine controller 42 controls the three-position four-way reversing valve 34 to return to the middle position. In this process, because the load will still rotate before deceleration and stop, the energy in the load rotation process is converted into electrical energy by the electric generator 10 and stored in the electrical energy storage unit 52, and the hydraulic energy generated by the hydraulic pump / motor 20 will be stored in the accumulator 51.

[0047] In the above braking process, the electric generator 10 works in the generator mode and recovers energy through the electric energy storage unit 51, that is, the electrical recovery mode is used as the main energy recovery mode.

[0048] 2. During load braking, when the control handle 51 returns to the middle position and is then pushed in the opposite direction, it is judged as rapid braking, and the hydraulic pump / motor 20 is controlled to operate in pump mode. The whole machine controller 42 controls the opening area of ​​the hydraulic pump / motor 20 to increase the displacement of the hydraulic pump / motor 20, thereby generating the main braking force and recovering the braking kinetic energy into the accumulator 51. During this process, the electric generator 20 operates in generator mode, and the speed of the electric generator 10 is rapidly decelerated. At this time, the electric generator 10 outputs a relatively small power, but because the load will still rotate before it is rapidly decelerated and stopped, a small amount of energy during the rotation of the load is converted into electrical energy by the electric generator 10.

[0049] In the above braking process, the hydraulic pump / motor 20 works in the pump mode, and the main energy recovery is performed through the accumulator 51, that is, the hydraulic recovery mode is used as the main energy recovery mode.

[0050] It should be noted that the three-position four-way reversing valve 34 returns to the middle position, which means that the P oil inlet and the A working port are cut off, and the B working port and the T oil return port are cut off.

[0051] The above-mentioned speed threshold is a value set according to actual conditions and a large amount of experience, and the speed threshold is set in the second controller 44 or the whole machine controller 42.

[0052] In the present invention, during the counterclockwise rotation start and braking process of the load, the three-position four-way reversing valve 34 works in the right position. At this time, the P oil inlet and the B working port are connected, and the A working port and the T oil return port are connected. The control method of the present invention is the same as the control method of the above-mentioned counterclockwise rotation of the load, so it will not be described in detail.

[0053] 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 rotary drive device based on electro-hydraulic composite drive, characterized in that: It comprises an electric generator, a hydraulic pump / motor, a hydraulic circuit and a rotating part, wherein the first end of the rotating shaft of the electric generator is transmission-connected to the rotating part, the second end of the rotating shaft of the electric generator is transmission-connected to the rotating shaft of the hydraulic pump / motor, and the hydraulic chamber 1 and the hydraulic chamber 2 of the hydraulic pump / motor are both connected to the hydraulic circuit; The hydraulic circuit includes an electric motor, a hydraulic pump, a one-way valve and a three-position four-way reversing valve. The output shaft of the electric motor is connected to the rotating shaft of the hydraulic pump. 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 inlet 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 hydraulic chamber one and the hydraulic chamber two in a one-to-one correspondence.

2. A rotary drive device based on electro-hydraulic composite drive according to claim 1, characterized in that: The hydraulic circuit also includes two oil-replenishing one-way valves and two safety valves, the oil inlets of the two oil-replenishing one-way valves and the oil outlets of the two safety valves are connected to the oil tank, the oil outlet of one of the oil-replenishing one-way valves and the oil inlet of the safety valve are respectively connected to the pipeline between the A working port of the three-position four-way reversing valve and the hydraulic chamber one, and the oil outlet of the other oil-replenishing one-way valve and the oil inlet of the safety valve are respectively connected to the pipeline between the B working port of the three-position four-way reversing valve and the hydraulic chamber two.

3. A rotary drive device based on electro-hydraulic composite drive according to claim 1 or 2, characterized in that: The hydraulic circuit also includes a safety valve three, the oil outlet of the safety valve three is connected to the oil tank, and the oil inlet of the safety valve three is connected to the pipeline between the oil inlet of the one-way valve and the oil outlet of the hydraulic pump.

4. The rotary drive device based on electro-hydraulic composite drive according to claim 3, characterized in that: It also includes a control system, which includes a control handle, a whole machine controller, a first controller and a second controller. The signal output end of the control handle is connected to the signal input end of the whole machine controller, and the whole machine controller is bidirectionally electrically connected to the first controller and the second controller respectively; the signal output end of the first controller is connected to the control end of the electric motor, the signal output end of the second controller is connected to the control end of the electric generator, and the signal output end of the whole machine controller is respectively connected to the control end of the hydraulic pump / motor and the electromagnetic end of the three-position four-way reversing valve.

5. The rotary drive device based on electro-hydraulic composite drive according to claim 4, characterized in that: It also includes an energy recovery unit, which includes an accumulator and an electric energy storage unit. The oil port of the accumulator is connected to the pipeline between the oil outlet of the one-way valve and the P oil inlet of the three-position four-way reversing valve; the power supply end of the electric energy storage unit is respectively connected to the power supply end of the first controller and the second controller.

6. The rotary drive device based on electro-hydraulic composite drive according to claim 5, characterized in that: A pressure sensor is installed at the oil port of the accumulator, and a sampling end of the pressure sensor is connected to a signal input end of the whole machine controller.

7. The rotary drive device based on electro-hydraulic composite drive according to claim 5, characterized in that: The electrical energy storage unit includes a rechargeable battery.

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