Electro-hydraulic actuator for roll-on-roll-off ship springboard

Abstract

The invention relates to an electro-hydraulic actuator for a roll-on-roll-off ship springboard, which comprises a motor driving mechanism, a bidirectional hydraulic pump and a hydraulic cylinder, a position sensor in the hydraulic cylinder is mounted on an oil cylinder to send a signal to a piston rod, control the oil cylinder to stretch out and retract, and feed back a signal to control the stroke. A bidirectional oil inlet and an oil outlet of the bidirectional hydraulic pump are respectively connected with a piston and a piston rod of the oil cylinder; the closed oil tank comprises an oil filling port and a liquid level discharging port, is installed on the valve block and is kept on the same axis with the coupler and the motor. A motor in the motor driving mechanism directly controls and drives the bidirectional hydraulic pump to rotate forwards and backwards through an external power source, and therefore steering switching of oil supply and oil suction of the bidirectional hydraulic pump is achieved. The electro-hydraulic actuator adopts electrical-mechanical-hydraulic conversion. Compared with an existing actuator control scheme, the control efficiency is high, control is accurate, stretching and retracting can be achieved only through positive and negative rotation of a motor without valve control, and automatic control and upper computer online automatic operation can also be conducted.

Description

Technical Field

[0001] The invention relates to a gangway of a ro-ro ship, and in particular to an electro-hydraulic actuator used for the gangway of a ro-ro ship. Background Art

[0002] The tail jump of the 7000-car ro-ro ship, including the side jump and bow jump, uses an ultra-large tonnage electro-hydraulic actuator with an output force of nearly 500 tons. During cargo loading and unloading, it should be kept within an angle range with the dock ground, that is, between about 4 and 8 degrees. If the angle is too large, the car driving on the ramp will touch the ground. And with the change of loading conditions or tide, the angle between the ramp and the ground is kept within the normal range. In the past, ro-ro ships were locked step by step by mechanical latches, and the control angle accuracy was low, which was not easy to integrate.

[0003] In addition, freight vehicles can not only enter and exit from the stern of the ship, but also drive to the various decks of the cabin to load and unload containers. The traditional hydraulic system used in the vehicle access equipment is connected by pipelines or hard pipes using welding methods. It not only occupies a large space, has poor stability, is easy to corrode, and has poor pipeline cleanliness. At the troubleshooting site, the equipment cannot be repaired without stopping the machine to eliminate the fault. Therefore, it is necessary to design an electro-hydraulic actuator for the gangway of a ro-ro ship. The electro-hydraulic actuator has the technical characteristics of an integrated highly integrated structure, extremely high power density, rapid control response, force adjustment and position control capabilities, adaptability to harsh environments, no leakage, low installation and maintenance costs, and high reliability.

[0004] Due to the limited space on board and the low precision of mechanical latches for step-by-step locking, the design of ship channel equipment needs to be as compact as possible, with stepless adjustment and locking, miniaturization, and light weight to facilitate maintenance. At the same time, due to the requirements of energy conservation and emission reduction, the original hydraulic system has low efficiency and cannot optimize the layout of the equipment. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the technical defects of the above mechanical latches such as step-by-step locking, adaptability to harsh environments, leakage, installation and maintenance costs, energy saving and emission reduction, and low reliability, and to provide an electro-hydraulic actuator for a roll-on / roll-off ship gangway, which can be used to drive various ship-sea channel equipment, so as to realize the impact force of water on the stern gangway when the ship-sea channel equipment is in a wading state, which is beneficial to improve the stability of the ship and other functions.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: an electro-hydraulic actuator for a ro-ro ship ramp, comprising a motor drive mechanism, a power unit, a bidirectional hydraulic pump, a hydraulic cylinder, a balancing valve, a relief valve, a hydraulically controlled one-way valve, a closed oil tank, a position sensor, a pressure sensor, and an oil replenishment valve; the hydraulic cylinder comprises an oil cylinder, a transition valve, a pressure sensor, and a position sensor, the position sensor being installed on the oil cylinder to send a signal to the piston rod, control the extension sensing and retraction sensing of the oil cylinder, perform signal feedback control stroke, and the pressure sensor performs signal feedback control force; the bidirectional hydraulic actuator comprises a motor drive mechanism, a power unit, a bidirectional hydraulic pump, a hydraulic cylinder, a balancing valve, a relief valve, a hydraulically controlled one-way valve, a closed oil tank, a position sensor, a pressure sensor, and an oil replenishment valve; the hydraulic cylinder comprises an oil cylinder, a transition valve, a pressure sensor, and a position sensor, the position sensor being installed on the oil cylinder to perform piston rod signal transmission, control the extension sensing and retraction sensing of the oil cylinder, perform signal feedback control stroke, and the pressure sensor performs signal feedback control force; the bidirectional hydraulic actuator comprises a motor drive mechanism, a power unit, a bidirectional hydraulic pump, a hydraulic cylinder, a balancing valve, a relief valve, a hydraulically controlled one-way valve, a closed oil tank, a position sensor, a pressure sensor, and an oil replenishment valve ... The hydraulic pump includes a two-way oil inlet and an oil outlet, which are installed in a closed oil tank; the two-way oil inlet and the oil outlet are respectively connected to the piston and the piston rod of the oil cylinder; the balance valve and the overflow valve are installed between the input ends at both ends of the front and rear chambers of the oil cylinder, and are used to control the pressure of the two chambers and lock the load to maintain the pressure; the closed oil tank includes an oil filling port and a liquid level discharge port, which are installed on the valve block and keep the same axis as the coupling and the motor; the motor in the motor drive mechanism is directly controlled by an external power supply to drive the two-way hydraulic pump to rotate forward and reverse, thereby realizing the steering switching of the oil supply and oil suction of the two-way hydraulic pump.

[0007] Furthermore, the motor drive mechanism is composed of a motor and a coupling. The motor is fixedly connected to the valve block via a fixed plate, and the motor output shaft is connected to the front end of a bidirectional hydraulic pump via a coupling.

[0008] Further, it is characterized in that: the coupling is composed of a cross coupling, which is divided into an upper coupling and a lower coupling, and is used for transmission between the motor and the bidirectional hydraulic pump; the upper coupling and the lower coupling connect the motor and the bidirectional hydraulic pump, and the bidirectional hydraulic pump is connected to the valve block.

[0009] Furthermore, the bidirectional hydraulic pump switches the inlet and outlet oil circuits and the oil tank connection channel through a one-way valve.

[0010] Furthermore, the bidirectional hydraulic pump is also provided with a valve block installed on three sides, which can adapt to multi-sided installation and the flow channels are interconnected; the valve block can be installed on the top, left side and right side, so that the direction of the regulating valve of the motor and the valve block can be adjusted, and the installation position can be kept consistent.

[0011] Furthermore, the oil replenishing valve is connected to the rod chamber of the oil cylinder, and is connected to the oil tank in a one-way through or cut-off manner. The closed oil tank converts the volume difference of the oil cylinder into compression energy or potential energy and stores it. When needed, the compression energy or potential energy is converted into hydraulic energy and released to replenish the electro-hydraulic actuator, and an oil distribution plate is arranged inside to distribute the hydraulic flow channel and protect the bladder of the energy storage box.

[0012] Furthermore, the closed oil tank includes an oil filling port and a liquid level discharge port, and the oil filling port is used for coordinated operation to realize the refueling and exhausting of the electro-hydraulic actuator.

[0013] Furthermore, the oil distribution plate is composed of a large oil distribution plate, a small oil distribution plate, and an oil distribution shaft, and the oil distribution shaft adopts a positioning pin to prevent rotation.

[0014] Furthermore, the power unit includes a valve block transition block, which is installed between the oil cylinder and the valve block; the transition block includes a rod cavity oil pipe and a rodless cavity oil pipe, and the rod cavity threaded hole oil channel and the rodless cavity threaded hole oil channel are installed between the front and rear end covers.

[0015] The beneficial effects of the present invention are:

[0016] 1. The electro-hydraulic actuator performs electrical-mechanical-hydraulic conversion. Compared with the existing traditional actuator control scheme, the equipment has high control efficiency and precise control. It can be extended and retracted by just reversing the motor without valve control. It can also be automatically controlled and automatically operated online with the host computer.

[0017] 2. The position control has high accuracy. The position control can be performed through the position sensor, which is suitable for the installation size space limitation. It is beneficial for multiple groups of electro-hydraulic actuators to lift the device at the same time. The position can be adjusted to the same state, thereby improving the overall reliability of the electro-hydraulic actuator;

[0018] 3. The electro-hydraulic actuator has high integration and high power-to-weight ratio. Since there is no traditional welding, ferrule, flaring and other types of hard pipes, it has no welding, zero leakage and high stability;

[0019] 4. The structure adopts three-sided mounting of valve block, which is more compact, more convenient for operation and maintenance, and lower maintenance cost.

[0020] 5. The electro-hydraulic actuator for the ro-ro ship ramp of the present invention can control the storage pressure of the closed oil tank, thereby reducing the pressure change range caused by the change of the actuator's cavity. The integrated piping form of the transition block makes the actuator highly integrated, avoiding the increase in maintenance costs caused by piping, and has a compact structure and is easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the hydraulic principle diagram of the electro-hydraulic actuator for the ro-ro ship ramp of the present invention;

[0022] Figure 2 It is a three-dimensional cross-sectional view of the power body of the electro-hydraulic actuator for the ro-ro ship ramp of the present invention;

[0023] Figure 3 It is a three-dimensional cross-sectional view of the auxiliary energy storage box of the electro-hydraulic actuator for the ro-ro ship ramp of the present invention;

[0024] Figure 4 It is a schematic diagram of an electro-hydraulic actuator for a ro-ro ship ramp of the present invention;

[0025] Figure 5 It is a cross-sectional view of the oil distribution plate of the electro-hydraulic actuator energy storage box for the ro-ro ship ramp of the present invention;

[0026] Figure 6 The present invention is a schematic diagram of the three-side installation of the electro-hydraulic actuator for the ro-ro ship ramp. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention is described in more detail below, and the accompanying drawings show an implementation example of the present invention. The present invention can be implemented in different forms and is not limited to this implementation example.

[0028] like Figures 1 to 6 As shown, an electro-hydraulic actuator for a ro-ro ship ramp of the present invention comprises a hydraulic pump 1, a motor 2, a hydraulically controlled one-way valve 3, a balancing valve 4, a one-way valve 5, a hydraulic cylinder 6, a relief valve 7, a rod chamber balancing valve 8, a closed oil tank 9, an oil replenishment valve 10, a main energy storage oil tank 11, a pump oil tank 12, a valve block 13, a coupling 14, a secondary energy storage oil tank 15, an oil filling port 16, a cover 17, an oil cylinder 18, a transition valve block 19, a transition plate 20, a pressure sensor 21, a position sensor 22, a bracket seat 23, a spherical bearing 24, a large oil distribution plate 25, a small oil distribution plate 26, an oil distribution shaft 27, and a nut 28.

[0029] The actuator is composed of a hydraulic cylinder 6, a support block, a pressure sensor 21, a position sensor 22, a transition plate 20, an integrated lifting ear rear end cover, and a sealing ring. The hydraulic cylinder 6 includes a piston and a piston rod.

[0030] The hydraulic cylinder 6 includes an oil cylinder 18, a transition valve block 19, a pressure sensor 21, and a position sensor 22. The oil cylinder 18 is provided with a pressure sensor 21 and a position sensor 22. The position sensor 22 is installed on the oil cylinder 18 to send a signal to the piston rod, control the extension and retraction of the oil cylinder 18, perform signal feedback control stroke, and the pressure sensor 21 performs signal feedback control force. The transition valve block 19 includes a rod chamber oil pipe and a rodless chamber oil pipe, which are installed between the front and rear end surface connection blocks.

[0031] The coupling 14 is composed of a cross coupling, which is divided into an upper half and a lower half coupling, and is used for transmission between the motor 2 and the hydraulic pump 1.

[0032] The motor 2 is fixedly connected to the valve block 13 through a fixed plate, and the motor output shaft is connected to the front end of the hydraulic pump 1 through a coupling 14; the upper half coupling and the lower half coupling connect the motor 2 and the hydraulic pump 1, and the hydraulic pump 1 is connected to the valve block 13 through a fixed plate. At the same time, the motor 2 directly controls the forward and reverse rotation of the hydraulic pump 1 through the external power supply of the junction box, thereby realizing the steering switch of the oil supply and oil suction of the hydraulic pump 1.

[0033] The hydraulic pump 1 is a bidirectional hydraulic pump, including a bidirectional oil inlet and an oil outlet, installed in a closed oil tank 9, and the bidirectional oil inlet and the oil outlet are respectively connected to the piston and the piston rod of the hydraulic cylinder 6.

[0034] The bidirectional hydraulic pump is also provided with a valve block 13 mounted on three sides and a closed oil tank 9. The valve block 13 mounted on three sides can adapt to multi-sided installation, and the flow channels are interconnected. The valve block 13 is built with a primary rotary seal, and the redundancy ensures the sealing reliability of the hydraulic pump. The valve block 13 can be installed on the top, left side, and right side of the three sides, and the direction of the regulating valve of the motor 2 and the valve block 13 can be adjusted, and the installation positions can be arranged in a consistent manner. The secondary rotary oil seal is installed between the coupling 14 and the hydraulic pump 1, and the redundancy ensures the sealing reliability.

[0035] The closed oil tank 9 includes an oil filling port 16 and a liquid level discharge port, which is installed on the valve block 13 and is kept on the same axis as the coupling 14 and the motor 2. The oil filling port 16 cooperates to achieve the oil filling and exhaust work of the electro-hydraulic actuator.

[0036] The main energy storage oil tank 11 is installed on the main oil tank, and the two secondary energy storage oil tanks 15 are installed on the transition plate 20 to form a power unit.

[0037] The main energy storage tank 11 and the secondary energy storage tank 15 use an oil distribution plate for oil flow distribution to avoid damage to the bladder and compensate for the flow of oil. The main energy storage tank 11 and the secondary energy storage tank 15 achieve volume difference compensation and rely on compressed inert gas to retract the cylinder.

[0038] The oil replenishing valve 10 is installed with the rod chamber of the hydraulic cylinder 6, and is connected to the oil tank in a one-way through or cutoff manner; the closed oil tank 9 converts the volume difference of the oil cylinder into compression energy or potential energy and stores it at an appropriate time, and when the system needs it, converts the compression energy or potential energy into hydraulic energy and releases it to replenish the supply system, and an oil distribution plate is arranged inside; the oil distribution plate distributes the hydraulic flow channel and can protect the bladder of the energy storage box.

[0039] The oil distribution plate is composed of a large oil distribution plate 25, a small oil distribution plate 26, and an oil distribution shaft 27. The oil distribution shaft 27 adopts a positioning pin to prevent rotation.

[0040] The balance valve 4 and the relief valve 7 are installed between the input ends of the front and rear chambers of the oil cylinder 18 to control the pressure of the two chambers and lock the load to maintain the pressure.

[0041] The control valve group controls the pressure of the piston of the oil cylinder 18 through the relief valve 7 to realize the work of pushing the oil cylinder 18 out, and the relief valve 7 controls the pressure of the piston rod of the oil cylinder 18 to realize the pressure of pushing the oil cylinder 18 to retract.

[0042] The valve block 13 is installed on three sides to realize the installation of various application scenarios of the electro-hydraulic actuator, including top-mounted, left-mounted, and right-mounted placement switching. The power body has a three-sided installation structure, which can be flexibly adjusted to top-mounted 29, right-mounted 30, and left-mounted 31, suitable for various working conditions at customer sites.

[0043] The implementation process of the present invention:

[0044] The retained pressure of the closed tank hydraulic actuator is the volume difference between the extension and retraction of the actuator, which is used to add oil, replenish oil, and limit and reduce the compensation pressure value of the actuator. The bidirectional hydraulic pump is installed in the closed tank with the inlet and outlet of the motor, which are connected to the actuator piston and the actuator piston rod respectively, pushing the piston rod to extend and retract.

[0045] The closed oil tank electro-hydraulic actuator of the present invention can be installed on three sides at will, so as to be freely installed on the actuator in three directions: the top, the left side and the right side of the actuator.

[0046] The closed oil tank electro-hydraulic actuator of the present invention makes the actuator highly integrated through the piping form of the bridge block, avoiding the increase in maintenance costs caused by welding piping and ferrule piping, and has a compact structure and is easy to use.

[0047] The position sensor of the present invention controls the stroke of the piston rod extension and retraction, and the output signal of the feedback module is sent to the actuator. The actuator is used to receive the output of the feedback module and generate a stroke signal, thereby controlling the actuator to avoid stroke overshoot and stroke control.

[0048] The energy storage oil tank of the present invention can reduce the volume change of the actuator by controlling the retained air in the closed oil tank. The retained pressure is the volume difference between the extension and retraction of the actuator, which is used for refueling, replenishing oil and limiting and reducing the compensation pressure value of the actuator.

[0049] The above implementation cases only illustrate several embodiments of the present invention and cannot be understood as limitations on the patent of the present invention. Based on this implementation case, the electro-hydraulic actuator of the present invention can also be improved to a certain extent. Therefore, the scope of patent protection of the present invention shall be based on the attached claims.

Claims

1. An electro-hydraulic actuator for a ro-ro ship ramp, Features: It includes a motor drive mechanism, a power unit, a bidirectional hydraulic pump, a hydraulic cylinder, a balance valve, a relief valve, a hydraulically controlled one-way valve, a closed oil tank, a position sensor, a pressure sensor, and an oil replenishment valve; the hydraulic cylinder includes an oil cylinder, a transition valve, a pressure sensor, and a position sensor. The position sensor is installed on the oil cylinder to send a signal from the piston rod, control the extension and retraction of the oil cylinder, and perform signal feedback control stroke, and the pressure sensor performs signal feedback control force; the bidirectional hydraulic pump includes a bidirectional oil inlet and an oil outlet, which are installed in the closed oil tank; the bidirectional oil inlet and the oil outlet are connected to the piston and the piston rod of the oil cylinder respectively; the balance valve and the relief valve are installed between the input ends at both ends of the front and rear chambers of the oil cylinder, and are used to control the pressure of the two chambers and lock the load to maintain the pressure; the closed oil tank includes an oil filling port and a liquid level discharge port, which are installed on the valve block and are kept on the same axis as the coupling and the motor; the motor in the motor drive mechanism directly controls the forward and reverse rotation of the bidirectional hydraulic pump through an external power supply, thereby realizing the steering switching of the oil supply and oil suction of the bidirectional hydraulic pump.

2. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, It is characterized in that: It is characterized in that: The motor drive mechanism is composed of a motor and a coupling. The motor is fixedly connected to the valve block through a fixing plate, and the motor output shaft is connected to the front end of a bidirectional hydraulic pump through a coupling.

3. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 2, It is characterized in that: It is characterized in that: The coupling is composed of a cross coupling, which is divided into an upper coupling and a lower coupling, and is used for transmission between the motor and the bidirectional hydraulic pump; the upper coupling and the lower coupling connect the motor and the bidirectional hydraulic pump, and the bidirectional hydraulic pump is connected to the valve block.

4. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, Features: The bidirectional hydraulic pump switches the inlet and outlet oil circuits and the oil tank connection channel through a one-way valve.

5. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, Features: The bidirectional hydraulic pump is also provided with a valve block mounted on three sides, which can adapt to multi-side installation and the flow channels are interconnected; the valve block can be installed on the top, left and right sides, so that the direction of the regulating valve of the motor and the valve block can be adjusted, and the installation position can be kept consistent.

6. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, Features: The oil replenishing valve is connected to the rod chamber of the oil cylinder, and is connected to the oil tank in a one-way through or cutoff manner. The closed oil tank converts the volume difference of the oil cylinder into compression energy or potential energy and stores it. When needed, the compression energy or potential energy is converted into hydraulic energy and released to replenish the electro-hydraulic actuator. An oil distribution plate is arranged inside to distribute the hydraulic flow channel and protect the bladder of the energy storage box.

7. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, Features: The closed oil tank comprises an oil filling port and a liquid level discharge port, and the oil filling port is used for coordinated operation to realize the refueling and exhausting work of the electro-hydraulic actuator.

8. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, Features: The oil distribution plate is composed of a large oil distribution plate, a small oil distribution plate and an oil distribution shaft, and the oil distribution shaft adopts a positioning pin to prevent rotation.

9. The electro-hydraulic actuator for a ro-ro ship ramp according to claim 1, Features: The power unit includes a valve block transition block, which is installed between the oil cylinder and the valve block; the transition block includes a rod cavity oil pipe and a rodless cavity oil pipe, and the rod cavity threaded hole oil channel and the rodless cavity threaded hole oil channel are installed between the front and rear end covers.

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