Power device for EHA control

Abstract

The invention relates to a power device for EHA control. A servo motor is connected with an oil pump block through an oil pump end cover, a cylinder body is installed in the pump block, a plunger is installed at one end of the cylinder body, the other end of the cylinder body is in close clearance fit with an oil distribution shaft to rotate, and the plunger is assembled in a radial hole of the cylinder body; the plunger ball head is meshed with the bearing, rotates along with the radial direction of the cylinder body and is used for absorbing and discharging oil; one end of the oil pump block body is provided with an oil distribution shaft, and the other end of the oil pump block body is provided with a pressurizing oil tank; the servo motor is connected with and drives the cylinder body to rotate through a coupler. The power device adopts a radial plunger pump structure of a plunger / cylinder pair, has a highly integrated design, and effectively reduces the size and the weight. And an overflow valve is arranged to protect the oil cylinder on the load side. The hydraulic lock is arranged, so that the position of the oil cylinder is bidirectionally locked. The pump system is supplemented with oil in time by arranging a pressurizing oil tank, an oil supplementing reversing valve and the like.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic technology such as a micro hydraulic system and an electro-hydraulic actuator (EHA), and in particular to a power device for controlling an electro-hydraulic actuator (EHA). Background Art

[0002] EHA technology combines the advantages of electromechanical and electrohydraulic technologies, providing significant energy saving advantages. It drives a bidirectional pump through a servo motor to achieve precise energy conversion and control. This technology is widely used in the aviation industry, ship valves and other fields, and can provide high output force without a mechanical gearbox, with high power density and excellent dynamic performance.

[0003] As the core component of EHA, the power head usually includes a gear pump or radial pump, which is responsible for converting mechanical energy into hydraulic energy. In high-pressure and ultra-high-pressure systems, the design of the power head needs to meet more stringent requirements to ensure the reliability and performance of the system.

[0004] The gear pump transfers hydraulic oil from the low pressure area to the high pressure area through the meshing of gears. It has a simple design and relatively low manufacturing cost, and is suitable for a variety of industrial applications. The working pressure of a bidirectional external meshing gear pump is usually 12MPa, and the volumetric efficiency is about 80%. Due to its structural design, its pressure and volumetric efficiency are relatively low, which limits its application.

[0005] Bidirectional radial pumps are valued for their high volumetric efficiency (over 90%) and high working pressure (up to 70MPa), and are particularly suitable for applications requiring high pressure and precise small flow control. The design of radial pumps usually includes multiple plungers that rotate around a common axis to provide a continuous and stable flow of hydraulic oil.

[0006] In view of the structural defects and practical needs of the above-mentioned gear pump device, the present invention aims to design a micro power device with a simple structure that can be used for high pressure and ultra-high pressure, especially a power device controlled by an electro-hydraulic actuator (EHA). Summary of the invention

[0007] The object of the present invention is to provide a power device with novel and compact structure which can be used for micro high-voltage or ultra-high-voltage systems, electro-hydraulic actuator (EHA) control and other equipment.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention is: a power device for EHA control, including a plunger, a cylinder body, an oil pump block, an oil distribution shaft, a pressurized oil tank, a servo motor, an oil replenishing valve assembly, a hydraulic lock assembly, and an overflow valve assembly. The servo motor is connected to the oil pump block through the oil pump end cover, and the pump block is equipped with a cylinder body. A plunger is installed at one end of the cylinder body, and the other end rotates with a tight clearance with the oil distribution shaft. The plunger is assembled in a radial hole of the cylinder body; the plunger ball head is engaged with the bearing and rotates radially with the cylinder body for oil suction and discharge; an oil distribution shaft is installed at one end of the oil pump block, and a pressurized oil tank is installed at the other end. The oil replenishing valve assembly, a hydraulic lock assembly, and an overflow valve assembly are installed in the oil pump block; the servo motor is connected through a coupling and drives the cylinder body to rotate.

[0009] Furthermore, the coupling adopts a cross slider structure for coaxial position adjustment.

[0010] Furthermore, an odd number of plungers is used to reduce flow pulsation.

[0011] Furthermore, the fitting clearance between the plunger and the cylinder body is not greater than 10 μm; the fitting clearance between the cylinder body 4 and the oil distribution shaft 6 is not greater than 10 μm.

[0012] Furthermore, the oil distribution shaft and the cylinder body form a rotating pair, the shaft is flow-distributed, and an A / B port is opened.

[0013] Furthermore, the pressurized oil tank is used to store hydraulic oil medium, and a hollow rubber ball is installed to provide compensation force for the pressurized oil tank.

[0014] Furthermore, the bearing and the plunger move in coordination, and a deep groove ball bearing made of steel or ceramic material is adopted.

[0015] Furthermore, the oil replenishing valve assembly is installed in the oil pump block in a plug-in manner, and is composed of a valve core, a valve sleeve, a limit shaft sleeve, and an end plug to form an O-type three-position three-way valve; wherein the valve core is installed in the oil pump block through the valve sleeve, and a limit shaft sleeve and an end plug are respectively provided at both ends.

[0016] Furthermore, the hydraulic lock assembly is installed in the oil pump block in an insert-type manner, and consists of a valve core, a valve sleeve, a one-way valve, and an end plug, and is used for bidirectional locking of the cylinder position. The valve core is installed in the oil pump block through the valve sleeve, and the two ends are respectively connected to the one-way valve and the end plug.

[0017] Furthermore, the overflow valve assembly is installed in the oil pump block in a plug-in manner, and consists of a valve core, a valve seat, a butterfly spring, a spring seat, a valve body, and a pressure-regulating screw, and is used to provide safety pressure protection and overload overflow, wherein the valve core is installed in the oil pump block through the valve seat, and the upper end of the valve core is connected to the pressure-regulating screw in the valve body through the spring seat and the butterfly spring.

[0018] Beneficial effects of the present invention:

[0019] The power device of the present invention adopts a micro, ultra-high pressure, high volumetric efficiency, two-way pump-controlled closed system, and its beneficial effects are mainly reflected in the following points:

[0020] 1. Innovative structural design: The power unit adopts a radial piston pump structure of plunger / cylinder pair, which has a highly integrated design and effectively reduces volume and weight.

[0021] 2. Safety protection system pressure (overflow): By setting an overflow valve, the load-side cylinder is protected.

[0022] 3. Position locking: By configuring a hydraulic lock, the cylinder position can be locked in both directions.

[0023] 4. Closed system oil replenishment: timely replenish oil to the pump system by configuring a pressurized oil tank, oil replenishment reversing valve, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural diagram of the power device in the present invention;

[0025] Figure 2 It is a structural diagram of the oil replenishment valve assembly 20 of the power device in the present invention;

[0026] Figure 3 It is a structural diagram of the hydraulic lock assembly 30 of the power device in the present invention;

[0027] Figure 4 It is a structural diagram of the overflow valve assembly 40 of the power device in the present invention;

[0028] Figure 5 It is a schematic diagram of the power device principle of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with embodiments and drawings.

[0030] like Figure 1 As shown in the figure, the power device for EHA control of the present invention mainly consists of a cross coupling 1, an oil pump end cover 2, a plunger 3, a cylinder body 4, an oil pump block 5, an oil distribution shaft 6, a pressurized oil tank 7, a servo motor 8, a bearing 9, a clamp 10, a sealing ring 11, a positioning pin 12, a plug 13, a hollow rubber ball 14, an oil replenishment valve assembly 20, a hydraulic lock assembly 30, an overflow valve assembly 40 and other components. Its working principle is as follows Figure 5 shown.

[0031] Oil pump end cover 2: one end is fixedly mounted on the servo motor 7, and the other end is connected to the oil pump block 5; the plunger 3 is assembled in the radial hole of the cylinder body 4; the ball head of the plunger 3 is engaged with the bearing 9, and rotates radially with the cylinder body 4 for oil suction and discharge; the plunger 3 is installed at one end of the cylinder body 4, and the other end rotates with the oil distribution shaft 6 in close clearance fit; the oil distribution shaft 6 is installed at one end of the oil pump block 5, and the pressurized oil tank 7 is installed at the other end. At the same time, the oil replenishment valve assembly 20, the hydraulic lock assembly 30, the overflow valve assembly 40, etc. are all installed in the oil pump block 5; one end of the cross coupling 1 is connected to the oil pump cylinder body 4, and the other end is connected to the servo motor 7; the servo motor 8 is used to provide power, connect and drive the cylinder body 4 to rotate.

[0032] Preferably, the coupling 1: adopts a cross slider design to adjust the position coaxially in time.

[0033] Preferably, the plunger 3 is generally an odd number of plungers such as 3, 5, 7, 9, etc., which can reduce flow pulsation. The ball head of the plunger 3 is engaged with the bearing 9 and rotates radially with the cylinder body 4 to absorb and discharge oil. The matching clearance with the cylinder body 4 is not greater than 10μm. The diameter of the plunger 3 can be 3.5, 6, 8, 12, etc.

[0034] Preferably, the cylinder body 4 and the oil distribution shaft 6 rotate with a tight clearance fit, and the fitting clearance is no more than 10 μm.

[0035] Preferably, the oil distribution shaft 6 and the cylinder body 4 form a rotating pair, the shaft is flow-distributed, and an A / B port is opened.

[0036] Preferably, the pressure oil tank 7 stores hydraulic oil medium, is equipped with a hollow rubber ball 14 and provides oil replenishment pressure, and is generally charged to a pressure of 0.3-1 bar.

[0037] Preferably, the servo motor 8 (or AC motor) converts electrical energy into hydraulic energy output through mechanical power transmission. When the plunger 3 diameter = φ3.5, the plunger arrangement is 3, and the displacement is 0.086cc, the servo motor 8 power is configured to be 120W; when the plunger 3 diameter = φ12, the displacement is 7.6cc, the servo motor 8 power is configured to be 15kW.

[0038] Preferably, the bearing 9 provides low friction and moves in coordination with the plunger 3. It can be a deep groove ball bearing made of steel, ceramic or other materials.

[0039] Preferably, the clamp 10 is used to fix the pressurized oil tank 7 .

[0040] Preferably, the sealing ring 11 is used for sealing the outside of the pressurized oil tank 7 .

[0041] Preferably, the positioning pin 12 is used to position and fix the oil distribution shaft 6 .

[0042] Preferably, the plug 13 is connected to the oil tank 7 and can be used to add hydraulic oil after being unscrewed.

[0043] Preferably, the hollow rubber ball 14 is used to pressurize the oil tank 7 to provide compensation force, and its working principle is similar to that of a bladder accumulator.

[0044] Preferably, the oil replenishment valve assembly 20: Figure 2 As shown, the plug-in type is installed in the oil pump block 5, and is composed of a valve core 21, a valve sleeve 22, a limit sleeve 23, an end plug 24, etc. The principle is an O-type three-way valve with three positions. The valve core 21 is installed in the oil pump block 5 through the valve sleeve 22, and a limit sleeve 23 and an end plug 24 are respectively provided at both ends.

[0045] Preferably, the hydraulic lock assembly 30: Figure 3 As shown, the plug-in type is installed in the oil pump block 5, and is composed of a valve core 31, a valve sleeve 32, a one-way valve 33, an end plug 34, etc., and is used for bidirectional locking of the oil cylinder position. The valve core 31 is installed in the oil pump block 5 through the valve sleeve 32, and the two ends are connected to the one-way valve 33 and the end plug 34 respectively.

[0046] Preferably, the overflow valve assembly 40: Figure 4 As shown, the plug-in type is installed in the oil pump block 5, and is composed of a valve core 41, a valve seat 42, a spring seat 43, a butterfly spring 44, a valve body 45, a pressure regulating screw 46, etc., which is used to provide safety pressure protection and overload overflow. The rated pressure of the overflow valve assembly 40 can reach 70MPa. The valve core 41 is installed in the oil pump block 5 through the valve seat 42, and the upper end of the valve core 41 is connected to the pressure regulating screw 46 in the valve body 45 through the spring seat 43 and the butterfly spring 44.

Claims

1. A power device for EHA control, characterized in that: It includes a plunger, a cylinder body, an oil pump block, an oil distribution shaft, a pressurized oil tank, a servo motor, an oil replenishment valve assembly, a hydraulic lock assembly, and an overflow valve assembly. The servo motor is connected to the oil pump block through the oil pump end cover. The oil pump block is equipped with a cylinder body. A plunger is installed at one end of the cylinder body, and the other end rotates with a tight clearance with the oil distribution shaft. The plunger is assembled in the radial hole of the cylinder body; the plunger ball head engages with the bearing and rotates radially with the cylinder body for oil suction and discharge; an oil distribution shaft is installed at one end of the oil pump block, and a pressurized oil tank is installed at the other end. The oil replenishment valve assembly, a hydraulic lock assembly, and an overflow valve assembly are installed in the oil pump block; the servo motor is connected through a coupling and drives the cylinder body to rotate.

2. The power device for EHA control according to claim 1, characterized in that: The coupling adopts a cross slider structure for coaxial position adjustment.

3. The power device for EHA control according to claim 1, characterized in that: The plunger adopts an odd number of plungers to reduce flow pulsation.

4. The power device for EHA control according to claim 1, characterized in that: The fitting clearance between the plunger and the cylinder body is not greater than 10 μm; the fitting clearance between the cylinder body 4 and the oil distribution shaft 6 is not greater than 10 μm.

5. The power device for EHA control according to claim 1, characterized in that: The oil distribution shaft and the cylinder body form a rotating pair, the shaft is flow-distributed, and A / B ports are opened.

6. The power device for EHA control according to claim 1, characterized in that: The pressurized oil tank is used to store hydraulic oil medium and is installed with a hollow rubber ball to provide compensation force for the pressurized oil tank.

7. The power device for EHA control according to claim 1, characterized in that: The bearing and the plunger move together and adopt deep groove ball bearings made of steel or ceramic materials.

8. The power device for EHA control according to claim 1, characterized in that: The oil replenishing valve assembly is installed in the oil pump block in a plug-in manner, and is composed of a valve core, a valve sleeve, a limit shaft sleeve, and an end plug to form an O-type three-position three-way valve; wherein the valve core is installed in the oil pump block through the valve sleeve, and a limit shaft sleeve and an end plug are provided at both ends.

9. The power device for EHA control according to claim 1, characterized in that: The hydraulic lock assembly is installed in the oil pump block in a plug-in manner. It consists of a valve core, a valve sleeve, a one-way valve, and an end plug. It is used for bidirectional locking of the cylinder position. The valve core is installed in the oil pump block through the valve sleeve, and the two ends are respectively connected to the one-way valve and the end plug.

10. The power device for EHA control according to claim 1, characterized in that: The overflow valve assembly is installed in the oil pump block in a plug-in manner, and consists of a valve core, a valve seat, a butterfly spring, a spring seat, a valve body, and a pressure-regulating screw. It is used to provide safety pressure protection and overload overflow. The valve core is installed in the oil pump block through the valve seat, and the upper end of the valve core is connected to the pressure-regulating screw in the valve body through the spring seat and the butterfly spring.

Images