CN117188561A - Electrohydraulic hybrid driving system - Google Patents
Electrohydraulic hybrid driving system Download PDFInfo
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- CN117188561A CN117188561A CN202310490139.8A CN202310490139A CN117188561A CN 117188561 A CN117188561 A CN 117188561A CN 202310490139 A CN202310490139 A CN 202310490139A CN 117188561 A CN117188561 A CN 117188561A
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- 238000012983 electrochemical energy storage Methods 0.000 claims abstract description 11
- 238000006073 displacement reaction Methods 0.000 claims description 15
- 230000005540 biological transmission Effects 0.000 claims description 5
- 230000000712 assembly Effects 0.000 claims description 3
- 238000000429 assembly Methods 0.000 claims description 3
- 238000011084 recovery Methods 0.000 abstract description 14
- 239000003921 oil Substances 0.000 abstract 4
- 239000010720 hydraulic oil Substances 0.000 abstract 2
- 238000010521 absorption reaction Methods 0.000 abstract 1
- 230000033001 locomotion Effects 0.000 description 15
- 238000010586 diagram Methods 0.000 description 13
- 238000004146 energy storage Methods 0.000 description 4
- 230000008929 regeneration Effects 0.000 description 4
- 238000011069 regeneration method Methods 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 3
- 238000009434 installation Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000007599 discharging Methods 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000003213 activating effect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
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Abstract
The invention relates to an electrohydraulic hybrid drive system, in particular to an electrohydraulic hybrid drive system with an energy recovery function. The hydraulic oil pump comprises a prime motor, a main pump driven by the prime motor, a main generator, an overflow valve, an electrochemical energy storage device powered by the main generator, at least one actuator assembly and an oil tank or an oil return low-pressure rail, wherein the hydraulic oil pump also comprises at least one common high-pressure rail powered by the main pump, each actuator assembly comprises a motor/generator, a first hydraulic pump/motor, a second hydraulic pump/motor and an actuator, the motor/generator is electrically connected with the electrochemical energy storage device, the oil absorption control valve corresponds to the oil outlet control valve in pairs, the four-quadrant operation of the first hydraulic pump/motor is controlled together, and the second hydraulic pump/motor is hydraulically coupled with the actuator through a pipeline. The invention can accurately control the speed of the motor/generator, reduce the rated power required by the motor/generator, and realize modularization and expandability on the basis of having an energy recovery function.
Description
Technical Field
The invention relates to an electrohydraulic hybrid drive system, in particular to an electrohydraulic hybrid drive system with an energy recovery function.
Background
The hydraulic drive has extremely high power density and good reliability. Conventional mobile machines (such as excavators and loaders) and fixed machines (such as mechanical arms) and the like are hydraulically driven, and a plurality of actuators are driven to move through a hydraulic system, so that the overall high-load movement of the machine is realized. These hydraulic systems typically consist of a centrally powered power source and hydraulic valves dedicated to each actuator. However, in high load movements of these hydraulic systems, the movement of the individual actuators is achieved by the flow control valves changing the flow of liquid in the hydraulic system, resulting in a large amount of hydraulic power being dissipated at the chokes in the form of heat energy during movement, so that the whole system becomes very inefficient.
A complex solution was adopted to recover the pressure drop in the flow line when the liquid flows back from the valve to the tank and the energy during the overload motion, as published in the seventh international hydrodynamic conference on study of the boom energy regeneration system for hybrid excavator (Kang b, oh s, 2010. A Study on the Boom Energy Regeneration System for a Hybrid expactor).
An eighth scandinavia hydrodynamic international conference on hydraulic cylinders controlled by float cup hydraulic transformers (Vael g., achten p., and patma j., 2003, cylinder Control with The Floating Cup Hydraulic Transformer) provides a solution for improving the energy efficiency of hydraulic systems by using hydraulic transformer control instead of conventional hydraulic valve control. A hydraulic transformer is hydraulically coupled to each load to vary the pressure of the concentrated power source to meet the load demand. This solution eliminates flow throttling and achieves energy recovery, but they are limited by current unresolved problems such as general size limitations on the market, limited ratio of transformation, and reduced efficiency at part load.
The first energy efficient hydraulic actuator for mobile machines published by the burrad labs fluid dynamic seminar (Rahmfeld r., and Ivantysynova m., 1998, energy Saving HydraulicActuators for Mobile Machines) provided a solution to replace valve control with displacement control. The movement of each actuator is controlled by adjusting the displacement of the hydraulic pump/motor dedicated to that actuator. The hydraulic pump/motor manages the full power of the load and is driven by a prime mover (e.g., an internal combustion engine of a mobile machine). This solution eliminates flow throttling and allows energy recovery, but has the disadvantages of higher cost of the arrangement of the servo valve to control the swash plate rotation, and reduced efficiency of the hydraulic pump or motor at the partial displacement setting, which is difficult to improve at the present time.
A solution for replacing valve control by electrohydraulic speed control is provided by a low power consumption compact electrohydraulic driver (Michel s., weber j., 2012, electrohydraulic Compact-drivesfor Low Power Applications considering Energy-efficiency and High Inertial Loads) issued in the seventh FPNI hydrodynamic doctor's seminar, which considers energy efficiency and high inertial load. A hydraulic pump/motor driven by the motor/generator is hydraulically coupled to the actuator, and movement of the actuator is controlled by adjusting the rotational speed of the hydraulic pump/motor. This solution eliminates flow throttling and achieves energy recovery to improve energy efficiency. Excellent control performance is achieved by precisely adjusting the speed of the motor/generator while ensuring high bandwidth control. However, all power managed by the load must come from the motor and the load itself. Thus, when the power increases to thousands of watts, cumbersome motors and expensive electronic drives are required, so this solution is controversial and even not viable. In addition, the energy required for the motor in the mobile machine must be provided by the on-board device, which requires the installation of a high-power generator driven by the internal combustion engine, a high-performance energy storage device, and an electrical device.
U.S. patent 62/80137, an apparatus (Device having hybrid hydraulic-electric architecture) having an electro-hydraulic mixing structure, provides an electro-hydraulic mixing scheme having multiple pressure rails. This scheme combines speed control with high and low pressure rails common to the entire device. One port of the hydraulic pump/motor is connected to the high pressure rail to hydraulically and electrically transfer power to or from the load by switching the valves to properly connect the two ports of the variable speed hydraulic pump/motor, the two ports of the hydraulic actuator that drives the load, the high pressure rail, and the low pressure rail. This approach reduces the power rating of the motor/generator and associated electrical components (e.g., electronic drives, generators, and energy storage devices). However, the complexity in terms of overall system design and control results is greatly increased. Each pressure rail must be supplied with oil separately, thus requiring additional components (e.g., motors, hydraulic pumps, electro-hydraulic valves, and hydropneumatic accumulators). At the same time, this solution requires a complex intelligent control algorithm and a plurality of sensors, allowing the switching valve to be quickly and properly controlled in order to enable/disable each pressure rail at the correct time.
U.S. patent 62/697226, electrohydraulic dual-power motion control system (Dual power electro-hydraulic motion control system), provides an electrohydraulic hybrid solution using pressure common rail technology (CommonPressure Rail, abbreviated as CPR), but when the chamber on the piston rod side of the hydraulic cylinder is at high pressure, i.e., load acting, the hydraulic pump/motor connecting the two ends of the common high pressure rail will not provide torque and pressure energy to the motor, and therefore will not have the function of energy recovery.
Meanwhile, in the above two patents, the hydraulic pump/motor is directly connected with the high-pressure common rail or the oil tank, and the flow difference generated by the asymmetric cavity of the hydraulic pump/motor needs to be compensated when the actuator moves, so that the concentrated power source part and each actuator part are designed into a whole, the complexity of the system design is increased, and the modularization and the expandability of the system cannot be realized.
Disclosure of Invention
The invention aims to provide an electrohydraulic hybrid driving system which can accurately control the speed of a motor/generator, reduce the rated power required by the motor/generator and realize modularization and expandability on the basis of having an energy recovery function.
An electrohydraulic hybrid driving system comprises a prime motor, a main pump driven by the prime motor, a main generator, an overflow valve, an electrochemical energy storage device powered by the main generator, at least one actuator assembly and an oil tank or an oil return low-pressure rail, wherein the electrohydraulic hybrid driving system also comprises at least one common high-pressure rail supplied by the main pump, each actuator assembly comprises a motor/generator, a first hydraulic pump/motor, a second hydraulic pump/motor and an actuator, the motor/generator is electrically connected with the electrochemical energy storage device, the first hydraulic pump/motor and the second hydraulic pump/motor are sequentially arranged on a transmission shaft of the motor/generator, the first hydraulic pump/motor is hydraulically coupled in the common high-pressure rail, an oil suction pipeline connected with the first hydraulic pump/motor and the common high-pressure rail is provided with two groups of oil suction control valves, an oil outlet pipeline connected with the oil tank or the oil return low-pressure rail is provided with two groups of oil outlet control valves, the oil suction control valves and the oil outlet control valves are in two-by-pair correspondence, the whole oil suction control valves and the oil outlet control valves are used for controlling four-quadrant operation of the first hydraulic pump/motor.
The rotation speed of the second hydraulic pump/motor is determined by the motor/generator, the torque acted on the second hydraulic pump/motor is provided by the motor/generator converting electric energy and the first hydraulic pump/motor converting pressure energy, on the basis of maintaining the efficiency advantage and control performance of the motor/generator speed control system, the hydraulic power is obviously improved by adding the hydraulic pump/motor, the rated power of the motor/generator required by the movement of the actuator is greatly reduced, and the cost is saved, and the compactness and the power density of the system are improved.
The common high-pressure rail is only hydraulically coupled with the first hydraulic pump/motor, and the actuators are not connected with the common high-pressure rail, so that each actuator assembly can be designed into an independent system, the installation is simpler, and the system has the characteristics of modularization and expansibility, and is suitable for various movable and fixed hydraulic machines.
On the basis of the scheme, the hydraulic accumulator is connected to the common high-pressure rail.
When the load of the actuator does work, the second hydraulic pump/motor can reversely provide torque for the motor/generator and the first hydraulic pump/motor, the originally dissipated energy is converted into electric energy and pressure energy which are respectively transmitted to the electrochemical energy storage device and the hydraulic energy storage device, so that energy recovery is realized, the energy recovery device has the substantial advantages of energy conservation and emission reduction, and the energy recovery device can be further applied to various hydraulic drive industrial machines and equipment related to energy regeneration.
On the basis of the scheme, each group of the oil suction control valve (21) and the oil discharge control valve (21') consists of at least one electrohydraulic digital valve or at least one electrohydraulic proportional valve or a combination of the electrohydraulic digital valve and the electrohydraulic proportional valve.
On the basis of the scheme, the first hydraulic pump/motor is provided with a first oil discharging pipeline connected with an oil tank or an oil returning low-pressure rail.
On the basis of the scheme, the first hydraulic pump/motor is a fixed-displacement hydraulic pump, a numerical variable-displacement hydraulic pump/motor or a proportional variable-displacement hydraulic pump/motor.
On the basis of the scheme, the main pump supplies oil to the first public high-pressure rail and the second public high-pressure rail with different pressures respectively through the two-position three-way valve, an oil suction pipeline connected with the first public high-pressure rail by the first hydraulic pump/motor is provided with two groups of oil suction control valves, an oil suction pipeline connected with the second public high-pressure rail by the first hydraulic pump/motor is provided with two groups of oil suction control valves, an oil outlet pipeline connected with the oil tank or the oil return low-pressure rail by the first hydraulic pump/motor is provided with four groups of oil outlet control valves, the oil suction control valves correspond to the oil outlet control valves in pairs, and the four quadrants of the first hydraulic pump/motor are controlled to operate by all the oil suction control valves and the oil outlet control valves together.
On the basis of the scheme, the parts of the pipelines, which are positioned at the two ends of the actuator, are respectively connected with a pressure reducing valve for protecting the pipelines.
On the basis of the scheme, the oil suction end and the oil outlet end of the second hydraulic pump/motor form a closed loop with the actuator through pipelines, a pair of check valves are respectively arranged at the parts of the pipelines at the two ends of the actuator, so that the independence of the actuator assembly is further improved, and the modularization is facilitated.
On the basis of the scheme, each actuator assembly further comprises a low-pressure accumulator, and the low-pressure ends of the check valve and the pressure reducing valve are connected with the low-pressure accumulator. The low-pressure accumulator replaces an oil tank or an oil return low-pressure rail, so that rated flow of the second hydraulic pump/motor can be reduced, power consumption of a motor/generator can be reduced, independence of an actuator assembly can be further improved, and modularization is facilitated.
Preferably, when the actuator is an asymmetric actuator, the check valve is a pilot check valve.
On the basis of the scheme, the second hydraulic pump/motor is provided with a second oil discharging pipeline connected with the low-pressure accumulator.
On the basis of the scheme, the second hydraulic pump/motor is an asymmetric hydraulic pump/motor, the oil return end of the second hydraulic pump/motor is connected with an oil tank or an oil return low-pressure rail, and the low-pressure ends of the check valve and the pressure reducing valve are both connected with the oil tank or the oil return low-pressure rail. An asymmetric hydraulic pump/motor is used as an extension of the second hydraulic pump/motor.
On the basis of the scheme, each actuator assembly further comprises a three-position four-way valve, one end of the second hydraulic pump/motor is connected with one working port of the three-position four-way valve, the other end of the second hydraulic pump/motor is connected with an oil tank or an oil return low-pressure rail, the three-position four-way valve is connected with the other working port of the connecting side of the second hydraulic pump/motor, the two working ports of the other side of the three-position four-way valve form a closed loop with the actuator through a pipeline, and the low-pressure end of the pressure reducing valve is connected with the oil tank or the oil return low-pressure rail. And (3) adding an expansion design of an open-loop actuator assembly of the three-position four-way valve.
On the basis of the scheme, each actuator assembly further comprises a third hydraulic pump/motor, one end of the second hydraulic pump/motor is connected with the actuator through a pipeline, the other end of the second hydraulic pump/motor is connected with an oil tank or an oil return low-pressure rail, and an oil suction end and an oil outlet end of the third hydraulic pump/motor form a closed loop with the actuator through pipelines. And the second hydraulic pump/motor is open-loop, and the third hydraulic pump/motor is closed-loop.
Preferably, the third hydraulic pump/motor is mounted on a drive shaft of the motor/generator.
Preferably, each of the actuator assemblies further includes an auxiliary motor/generator, and the third hydraulic pump/motor is mounted on a drive shaft of the auxiliary motor/generator. An extended design of the auxiliary motor/generator is added.
Preferably, the third hydraulic pump/motor has a third oil discharge pipeline connected with an oil tank or an oil return low-pressure rail.
Preferably, the low pressure end of the pressure reducing valve is connected with an oil tank or an oil return low pressure rail.
The invention has the advantages that:
(1) The rotation speed of the second hydraulic pump/motor is determined by the motor/generator, the torque acted on the second hydraulic pump/motor is provided by the motor/generator converting electric energy and the first hydraulic pump/motor converting pressure energy, on the basis of the efficiency advantage and the control precision of the speed control system of the motor/generator, the hydraulic power is obviously improved by adding the hydraulic pump/motor, the rated power of the motor/generator required by the movement of the actuator is greatly reduced, and the cost is saved, and the compactness and the power density of the system are improved.
(2) As can be seen from the above, in the mobile machine, less electric energy is required for the movement of the actuator, so that the configuration of the mobile power supply can be reduced, the cost can be saved, and the overall compactness of the machine can be improved.
(3) When the load of the actuator does work, the second hydraulic pump/motor can reversely provide torque for the motor/generator and the first hydraulic pump/motor, the originally dissipated energy is converted into electric energy and pressure energy which are respectively transmitted to the electrochemical energy storage device and the hydraulic energy storage device, so that energy recovery is realized, the energy recovery device has the substantial advantages of energy conservation and emission reduction, and the energy recovery device can be further applied to various hydraulic drive industrial machines and equipment related to energy regeneration.
(4) The common high-pressure rail is only hydraulically coupled with the first hydraulic pump/motor, and the actuators are not connected with the common high-pressure rail, so that each actuator assembly can be designed into an independent system, the installation is simpler, and the system has the characteristics of modularization and expansibility, and is suitable for various movable and fixed hydraulic machines.
Drawings
FIG. 1 is a schematic diagram of a system for a mobile hydraulic machine;
FIG. 2a is a schematic diagram of an alternative embodiment of the control valve of the present invention;
FIG. 2b is a schematic diagram of an alternative control valve of the present invention;
FIG. 2c is a schematic representation of an alternative embodiment of the control valve of the present invention;
FIG. 3 is a schematic illustration of a first hydraulic pump/motor alternative of the present invention;
FIG. 4 is a schematic diagram of a common high pressure rail alternative of the present invention;
FIG. 5 is a schematic diagram of a second hydraulic pump/motor alternative of the present invention;
FIG. 6 is a schematic diagram of an alternative embodiment of the present invention actuator assembly;
FIG. 7a is a schematic illustration of the present invention with the addition of a third hydraulic pump/motor alternative;
fig. 7b is a second schematic of the present invention with the addition of a third hydraulic pump/motor alternative.
Detailed description of the preferred embodiments
Example 1
As shown in fig. 1, the invention is applied to a system schematic diagram of a mobile hydraulic machine, an electrohydraulic hybrid driving system comprises a prime motor 1, a main pump 2 and a main generator 6 driven by an internal combustion engine 1, an overflow valve 5 for protecting the system, an electrochemical energy storage device 7 powered by the main generator 6, two actuator assemblies 8 and an oil tank or return low pressure rail 18, wherein the electrohydraulic hybrid driving system further comprises a common high pressure rail 3 supplied with oil by the main pump 2 and a hydraulic accumulator 4 connected to the common high pressure rail 3, each actuator assembly 8 comprises a motor/generator 9, a first hydraulic pump/motor 10, a second hydraulic pump/motor 11, an actuator 13 and a low pressure accumulator 17, the motor/generator 9 is electrically connected with the electrochemical energy storage device 7, the first hydraulic pump/motor 10 and the second hydraulic pump/motor 11 are sequentially arranged on a transmission shaft of the motor/generator 9, the first hydraulic pump/motor 10 is fixed in displacement and is hydraulically coupled in the common high pressure rail 3, an oil suction path connected with the common high pressure rail 3 is provided with two sets of oil suction control valves 21, the first hydraulic pump/motor 10 and the oil tank/motor 10 and the second hydraulic pump/motor 21 'are respectively connected with the oil suction control valves 21' and the oil discharge valves 13, and the two hydraulic pump/motor 21 'are respectively connected with the hydraulic pump/motor 13 and the oil discharge valves 13' and the two hydraulic pump/motor control valves 21 'are respectively, and the two hydraulic pump/motor control valves 21' are correspondingly connected with the hydraulic pump/motor control valves 13 and the hydraulic pump control valve 13.
Preferably, each group of the oil suction control valve 21 and the oil discharge control valve 21' is composed of an electrohydraulic digital valve.
The parts of the pipeline 12 positioned at the two ends of the actuator 13 are respectively connected with a pressure reducing valve 16, the oil suction end and the oil outlet end of the second hydraulic pump/motor 11 form a closed loop with the actuator 13 through the pipeline 12, the parts of the pipeline 12 positioned at the two ends of the actuator 13 are respectively provided with a pair of check valves 15, and the low pressure ends of the check valves 15 and the pressure reducing valves 16 are connected with a low pressure accumulator 17.
Preferably, when the actuator 13 is an asymmetric actuator, the check valve 15 is a pilot check valve.
The rotational speed of the first hydraulic pump/motor 10 is controlled by the motor/generator 9, whereby the flow of the first hydraulic pump/motor 10 is adjusted to meet the required movement of the hydraulic actuator 13. Typically, pressure sensors monitor the pressure across the hydraulic actuator 13, position sensors measure the position of the hydraulic actuator 13, and speed sensors detect the speed of the motor/generator 9. After the control algorithm receives the signals from the plurality of sensors, it activates the control valve 21 at the appropriate time to enable the first hydraulic pump/motor 10 to provide the appropriate torque to the drive shaft of the motor/generator 9.
It is also possible to actively control the pressure drop across the first hydraulic pump/motor 10 by adjusting the pressure of the common high pressure rail 3 instead of by activating the control valve 21 at the appropriate time, so that the first hydraulic pump/motor 10 can provide the appropriate torque to the drive shaft of the motor/generator 9.
Thus, the first hydraulic pump/motor 10 transfers energy from the common high pressure rail 3 to the load 14, thereby reducing the energy that needs to be transferred from the electrochemical energy storage device 7 to the load 14 by the electric motor/generator 9. In other words, the motor/generator 9, as a control element for the actuator 13, ensures the movement requirements of the load 14 even if its rated power is significantly lower than the total power required for the movement of the load 14.
Example 2
As shown in fig. 2a, an alternative embodiment of the control valve of the present invention is schematically shown, an actuator assembly 8, an oil suction pipeline connected to a common high-pressure rail 3 by a first hydraulic pump/motor 10 is provided with two sets of oil suction control valves 21, an oil outlet pipeline connected to an oil tank or an oil return low-pressure rail 18 by the first hydraulic pump/motor 10 is provided with two sets of oil outlet control valves 21', the oil suction control valves 21 correspond to the oil outlet control valves 21', each set of the oil suction control valves 21 and the oil outlet control valves 21' is composed of two electrohydraulic digital valves, and other components are the same as those in embodiment 1.
As shown in fig. 2b, a second schematic diagram of the control valve alternative of the present invention is shown, an actuator assembly 8, an oil suction pipeline connected to the common high-pressure rail 3 by the first hydraulic pump/motor 10 is provided with two sets of oil suction control valves 21, an oil outlet pipeline connected to the oil tank or the oil return low-pressure rail 18 by the first hydraulic pump/motor 10 is provided with two sets of oil outlet control valves 21', the oil suction control valves 21 correspond to the oil outlet control valves 21', each set of the oil suction control valves 21 and the oil outlet control valves 21' is composed of an electrohydraulic proportional valve, and other components are the same as those in embodiment 1.
As shown in fig. 2c, in the control valve alternative three schematic diagrams of the present invention, an actuator assembly 8, an oil suction pipeline connected to the common high-pressure rail 3 by the first hydraulic pump/motor 10 is provided with two sets of oil suction control valves 21, an oil outlet pipeline connected to the oil tank or the oil return low-pressure rail 18 by the first hydraulic pump/motor 10 is provided with two sets of oil outlet control valves 21', the oil suction control valves 21 correspond to the oil outlet control valves 21', and each set of the oil suction control valves 21 and the oil outlet control valves 21' is composed of a combination of an electrohydraulic digital valve and an electrohydraulic proportional valve, and other components are the same as those of embodiment 1.
Example 3
As shown in fig. 3, which is a schematic diagram of a first hydraulic pump/motor alternative of the present invention, an actuator assembly 8, the first hydraulic pump/motor 10 is a variable displacement hydraulic pump/motor, and the other components are the same as those of embodiment 1.
Preferably, the first hydraulic pump/motor 10 is a numerical variable displacement hydraulic pump/motor or a proportional variable displacement hydraulic pump/motor. The numerical variable displacement hydraulic pump/motor determines a numerical value by a discrete value of torque on the drive shaft, and the proportional variable displacement hydraulic pump/motor determines a numerical value by adjusting a proportional value of torque on the drive shaft.
Example 4
As shown in fig. 4, which is a schematic diagram of an alternative scheme of the common high-pressure rail of the present invention, an actuator assembly 8, the main pump 2 supplies oil to the first common high-pressure rail 3 and the second common high-pressure rail 3' with different pressures through two-position three-way valves 22, an oil suction pipeline connected with the first hydraulic pump/motor 10 and the first common high-pressure rail 3 is provided with two groups of oil suction control valves 21, an oil suction pipeline connected with the first hydraulic pump/motor 10 and the second common high-pressure rail 3' is provided with two groups of oil suction control valves 21, an oil outlet pipeline connected with the first hydraulic pump/motor 10 and the oil tank or the oil return low-pressure rail 18 is provided with four groups of oil outlet control valves 21', the oil suction control valves 21 and the oil outlet control valves 21' are respectively corresponding to each other, and the four quadrants of the first hydraulic pump/motor 10 are controlled to operate by the oil suction control valves 21 and the oil outlet control valves 21', and other components are the same as in embodiment 1.
The pressure drop across the first hydraulic pump/motor 10 is actively controlled by the first 3 and second 3' high pressure rails being of different pressure, instead of by actuating the control valve 21 at the appropriate time, so that the first hydraulic pump/motor 10 can provide the appropriate torque to the drive shaft of the motor/generator 9.
Example 5
As shown in fig. 5, which is a schematic diagram of a second hydraulic pump/motor alternative of the present invention, an actuator assembly 8, the second hydraulic pump/motor 11 is an asymmetric hydraulic pump/motor, the oil return end of the second hydraulic pump/motor 11' is directly connected to an oil tank or an oil return low pressure rail 18 instead of the hydro-pneumatic accumulator 17, and the low pressure ends of the check valve 15 and the relief valve 16 are connected to the oil tank or the oil return low pressure rail 18, and other components are the same as those of embodiment 1.
Example 6
As shown in fig. 6, an alternative embodiment of the actuator assembly of the present invention is shown, wherein the actuator assembly 8 further comprises a three-position four-way valve 23, one end of the second hydraulic pump/motor 11 is connected with one working port of the three-position four-way valve 23, the other end of the second hydraulic pump/motor is connected with an oil tank or an oil return low pressure rail 18, the other working port of the three-position four-way valve 23 on the connecting side of the second hydraulic pump/motor 11 is connected with the oil tank or the oil return low pressure rail 18, the two working ports on the other side of the three-position four-way valve 23 form a closed loop with the actuator 13 through a pipeline 12, the low pressure end of the pressure reducing valve 16 is connected with the oil tank or the oil return low pressure rail 18, and other components are the same as those in embodiment 1.
Example 7
As shown in fig. 7a, the present invention adds a third hydraulic pump/motor alternative scheme, an actuator assembly 8, the actuator assembly 8 further comprises a third hydraulic pump/motor 11', the third hydraulic pump/motor 11' is mounted on a transmission shaft of the motor/generator 9, one end of the second hydraulic pump/motor 11 is connected with the actuator 13 through a pipeline 12, the other end is connected with an oil tank or an oil return low pressure rail 18, an oil suction end and an oil outlet end of the third hydraulic pump/motor 11' form a closed loop with the actuator 13 through the pipeline 12, the third hydraulic pump/motor 11' is provided with a third oil discharge pipeline 20' connected with the oil tank or the oil return low pressure rail 18, and a low pressure end of the pressure reducing valve 16 is connected with the oil tank or the oil return low pressure rail 18.
As shown in fig. 7b, a second schematic diagram of the alternative solution of the third hydraulic pump/motor is added to the present invention, an actuator assembly 8 further comprises an auxiliary motor/generator 9' and a third hydraulic pump/motor 11', the third hydraulic pump/motor 11' is mounted on a transmission shaft of the auxiliary motor/generator 9', one end of the second hydraulic pump/motor 11 is connected with the actuator 13 through a pipeline 12, the other end is connected with an oil tank or an oil return low pressure rail 18, an oil suction end and an oil discharge end of the third hydraulic pump/motor 11' form a closed loop with the actuator 13 through the pipeline 12, the third hydraulic pump/motor 11' is provided with a third oil discharge pipeline 20' connected with the oil tank or the oil return low pressure rail 18, and a low pressure end of a pressure reducing valve 16 is connected with the oil tank or the oil return low pressure rail 18.
The above-described embodiments are applicable to a general-purpose multi-actuator mobile hydraulic machine, but can be extended to a general-purpose multi-actuator fixed hydraulic machine with simple modifications. For simplicity of design, the embodiments only show the case of two actuators and two high-pressure common rails, but even if more actuators and high-pressure rails are added, the design principle of the system is not changed. The foregoing description of the preferred embodiments of the invention includes both modifications and variations, and all equivalent and equivalent modifications which fall within the scope of the claims are intended to fall within the scope of the claims.
Claims (18)
1. An electrohydraulic hybrid drive system comprising a prime mover (1), a main pump (2) and a main generator (6) driven by the prime mover (1), an overflow valve (5), an electrochemical energy storage device (7) powered by the main generator (6), at least one actuator assembly (8) and an oil tank or return low pressure rail (18), characterized in that: the hydraulic system further comprises at least one public high-pressure rail (3) which is supplied with oil by a main pump (2), each actuator assembly (8) comprises a motor/generator (9), a first hydraulic pump/motor (10), a second hydraulic pump/motor (11) and an actuator (13), the motor/generator (9) is electrically connected with an electrochemical energy storage device (7), the first hydraulic pump/motor (10) and the second hydraulic pump/motor (11) are sequentially arranged on a transmission shaft of the motor/generator (9), the first hydraulic pump/motor (10) is hydraulically coupled in the public high-pressure rail (3), an oil suction pipeline connected with the public high-pressure rail (3) by the first hydraulic pump/motor (10) is provided with two groups of oil suction control valves (21), an oil outlet pipeline connected with an oil tank or an oil return low-pressure rail (18) by the first hydraulic pump/motor (10) is provided with two groups of oil suction control valves (21 '), the oil suction control valves (21) are in two-by-two correspondence with the oil suction control valves (21'), the first hydraulic pump/motor (10) and the oil suction control valves (21 ') are jointly controlled by the oil suction control valves (21'), and the second hydraulic pump/motor (11) is hydraulically coupled with the hydraulic system (13) by the hydraulic pump/actuator (13).
2. The electro-hydraulic hybrid drive system of claim 1, wherein: also comprises a hydraulic accumulator (4) connected to the common high-pressure rail (3).
3. The electro-hydraulic hybrid drive system of claim 1, wherein: each group of the oil suction control valve (21) and the oil discharge control valve (21') consists of at least one electrohydraulic digital valve or at least one electrohydraulic proportional valve or a combination of the electrohydraulic digital valve and the electrohydraulic proportional valve.
4. The electro-hydraulic hybrid drive system of claim 1, wherein: the first hydraulic pump/motor (10) is provided with a first oil drain line (19) connected to an oil tank or an oil return low pressure rail (18).
5. The electro-hydraulic hybrid drive system of claim 1, wherein: the first hydraulic pump/motor (10) is a fixed-displacement hydraulic pump, a numerical variable-displacement hydraulic pump/motor or a proportional variable-displacement hydraulic pump/motor.
6. The electro-hydraulic hybrid drive system of claim 1, wherein: the main pump (2) is used for supplying oil to a first public high-pressure rail (3) and a second public high-pressure rail (3 ') which are different in pressure respectively through a two-position three-way valve (22), two groups of oil suction control valves (21) are arranged on an oil suction pipeline connected with the first public high-pressure rail (3) by the first hydraulic pump/motor (10), two groups of oil suction control valves (21) are arranged on an oil suction pipeline connected with the second public high-pressure rail (3 '), four groups of oil outlet control valves (21 ') are arranged on an oil outlet pipeline connected with an oil tank or an oil return low-pressure rail (18) by the first hydraulic pump/motor (10), the oil suction control valves (21) and the oil outlet control valves (21 ') are in pairwise correspondence, and four-quadrant operation of the first hydraulic pump/motor (10) is controlled by the whole oil suction control valves (21) and the oil outlet control valves (21 ').
7. An electro-hydraulic hybrid drive system as set forth in any one of claims 1-6, wherein: the part of the pipeline (12) positioned at the two ends of the actuator (13) is respectively connected with a pressure reducing valve (16).
8. The electro-hydraulic hybrid drive system according to any one of claim 7, wherein: the oil suction end and the oil outlet end of the second hydraulic pump/motor (11) form a closed loop with the actuator (13) through a pipeline (12), and a pair of check valves (15) are respectively arranged at the parts of the pipeline (12) at the two ends of the actuator (13).
9. The electro-hydraulic hybrid drive system of claim 8, wherein: each actuator assembly (8) further comprises a low pressure accumulator (17), and the low pressure ends of the check valve (15) and the pressure reducing valve (16) are connected with the low pressure accumulator (17).
10. The electro-hydraulic hybrid drive system of claim 9, wherein: when the actuator (13) is an asymmetric actuator, the check valve (15) is a pilot check valve.
11. The electro-hydraulic hybrid drive system of claim 9, wherein: the second hydraulic pump/motor (11) is provided with a second oil discharge line (20) connected to the low-pressure accumulator (17).
12. The electro-hydraulic hybrid drive system of claim 8, wherein: the second hydraulic pump/motor (11) is an asymmetric hydraulic pump/motor, the oil return end of the second hydraulic pump/motor (11) is connected with an oil tank or an oil return low-pressure rail (18), and the low-pressure ends of the check valve (15) and the pressure reducing valve (16) are both connected with the oil tank or the oil return low-pressure rail (18).
13. The electro-hydraulic hybrid drive system of claim 7, wherein: each actuator assembly (8) further comprises a three-position four-way valve (23), one end of the second hydraulic pump/motor (11) is connected with one working port of the three-position four-way valve (23), the other end of the second hydraulic pump/motor is connected with an oil tank or an oil return low-pressure rail (18), the other working port of the three-position four-way valve (23) and the connecting side of the second hydraulic pump/motor (11) are connected with the oil tank or the oil return low-pressure rail (18), two working ports on the other side of the three-position four-way valve (23) and the actuator (13) form a closed loop through a pipeline (12), and the low-pressure end of the pressure reducing valve (16) is connected with the oil tank or the oil return low-pressure rail (18).
14. The electro-hydraulic hybrid drive system of claim 7, wherein: each actuator assembly (8) further comprises a third hydraulic pump/motor (11 '), one end of the second hydraulic pump/motor (11) is connected with the actuator (13) through a pipeline (12), the other end of the second hydraulic pump/motor is connected with an oil tank or an oil return low-pressure rail (18), and an oil suction end and an oil outlet end of the third hydraulic pump/motor (11') form a closed loop with the actuator (13) through the pipeline (12).
15. The electro-hydraulic hybrid drive system of claim 14, wherein: the third hydraulic pump/motor (11') is mounted on the drive shaft of the motor/generator (9).
16. The electro-hydraulic hybrid drive system of claim 14, wherein: each of said actuator assemblies (8) further comprises an auxiliary motor/generator (9 '), the third hydraulic pump/motor (11 ') being mounted on a drive shaft of the auxiliary motor/generator (9 ').
17. The electro-hydraulic hybrid drive system of claim 14, wherein: the third hydraulic pump/motor (11 ') is provided with a third oil drain line (20') connected to an oil tank or return low pressure rail (18).
18. The electro-hydraulic hybrid drive system of claim 14, wherein: the low-pressure end of the pressure reducing valve (16) is connected with an oil tank or an oil return low-pressure rail (18).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310490139.8A CN117188561A (en) | 2023-05-04 | 2023-05-04 | Electrohydraulic hybrid driving system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310490139.8A CN117188561A (en) | 2023-05-04 | 2023-05-04 | Electrohydraulic hybrid driving system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117188561A true CN117188561A (en) | 2023-12-08 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310490139.8A Pending CN117188561A (en) | 2023-05-04 | 2023-05-04 | Electrohydraulic hybrid driving system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117188561A (en) |
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2023
- 2023-05-04 CN CN202310490139.8A patent/CN117188561A/en active Pending
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