Electro-hydraulic actuating mechanism

Abstract

The invention relates to the field of electro-hydraulic actuating mechanisms, in particular to an electro-hydraulic actuating mechanism which comprises a box body, an end cover, a piston and a gear shaft. The box body comprises a piston cylinder for mounting a piston and a columnar cylinder for mounting a gear shaft, and one side of the columnar cylinder is communicated with the piston cylinder; the two end covers are fixedly connected to the two ends of the piston cylinder through screws correspondingly, an oil way is formed in each end cover, and the oil ways in the end covers communicate with the oil way formed in the wall of the piston cylinder. The electro-hydraulic actuating mechanism adopts a modular design and an internal limiting mode, so that the risk of leakage generated when the position of a switch is adjusted by the actuating mechanism can be avoided, the stroke adjustment of the actuating mechanism can be accurately realized by adjusting the position of a limiting cam, and the actuating mechanism adopts an integrated casting structure and is attractive and simple in appearance and convenient to process and assemble; the electric control unit can also adopt a modularized and miniaturized design, is compact in structure, can output the maximum pressure of 15Mpa, greatly saves the installation space, and is adaptive to a plurality of valves on the market.

Description

Technical Field

[0001] The present invention relates to the field of electro-hydraulic actuators, and particularly to an electro-hydraulic actuator. Background Art

[0002] Electro-hydraulic actuators are an important part of the industrial automation field, used to convert electrical signals into mechanical motion and control the opening and closing of devices such as valves and dampers. In recent years, with the development of Industry 4.0 and intelligent manufacturing, the intelligence, integration, and high precision of electro-hydraulic actuators have become the development trend. Modern electro-hydraulic actuators can not only achieve remote control and self-diagnosis, but also be seamlessly connected with other automation devices to improve production efficiency and safety.

[0003] When abnormal anti-offset ability, large torque, and relatively fast stroke speed are required, we often choose hydraulic actuators or electro-hydraulic actuators. Existing electro-hydraulic actuators are large and bulky, with problems such as unstable output torque and hydraulic oil leakage in the actuator, making it difficult to provide a stable operating environment and safety for equipment or devices.

[0004] Therefore, an electro-hydraulic actuator is proposed for the above problems. Summary of the Invention

[0005] In order to make up for the deficiencies of the prior art and solve at least one of the technical problems proposed in the background art.

[0006] The technical solution adopted by the present invention to solve its technical problems is: an electro-hydraulic actuator according to the present invention includes: a box body, the box body includes a piston cylinder for installing a piston and a columnar cylinder for installing a gear shaft, the axes of the piston cylinder and the columnar cylinder are perpendicular to each other, and one side of the columnar cylinder communicates with the piston cylinder; End caps, two of the end caps are respectively fixedly connected to both ends of the piston cylinder by screws, and an oil passage is provided inside each end cap, and the oil passage inside the end cap communicates with the oil passage provided in the piston cylinder wall; A piston, both ends of the piston are hermetically and slidably connected inside the piston cylinder, and a plurality of meshing teeth are evenly provided on the surface of the piston opposite to the columnar cylinder; A gear shaft, the gear shaft is rotatably connected inside the columnar cylinder, and the gear of the gear shaft meshes with the meshing teeth; the lower end of the gear shaft extends to the lower port position of the columnar cylinder, and a clamping groove is provided on the lower end surface of the gear shaft for cooperating with the torque input end of an external valve rod.

[0007] Preferably, a limiting cam is fixedly connected to the gear shaft; Two limiting bolts are symmetrically threadedly connected to the outer wall of the columnar cylinder, and the limiting bolts are used to limit the rotation angle of the limiting cam.

[0008] Preferably, a dial is provided at the center of the upper end of the columnar cylinder. The upper end of the gear shaft penetrates through the upper end of the columnar cylinder and is fixedly connected with a sealing cover. A pointer is arranged on the sealing cover, and the pointer cooperates with the dial to indicate the rotation angle of the gear shaft.

[0009] Preferably, a replaceable adapter assembly is provided at the lower end of the gear shaft. The replaceable adapter assembly includes an adapter. One end of the adapter is inserted into the card slot, and the other end of the adapter is provided with a secondary card slot adapted to the torque input end of the external valve stem. A disc is radially provided on the outer circumference of the other end of the adapter, and a plurality of limiting protrusions are provided on the outer circumference of the disc. A concave portion adapted to the disc and a relief opening adapted to the shape of the limiting protrusion are provided on the lower end surface of the gear shaft.

[0010] Preferably, a plurality of arc-shaped chutes are circumferentially arranged at the edge position of the lower end surface of the gear shaft. A slider is slidably connected in the chute, and an insertion bar is fixedly connected to the slider. A sliding layer is provided on the outer side wall of the limiting protrusion. By rotating the slider, the insertion bar is pushed and inserted into the sliding layer.

[0011] Preferably, a positioning pin is rotatably connected in each relief opening. A toothed ring is coaxially fixedly connected to the outer circumference of the positioning pin, and an anti-disengagement rod is radially fixedly connected to the outer circumference of the toothed ring. A positioning hole adapted to the positioning pin is provided on the limiting protrusion, and a fan-shaped anti-disengagement layer is further provided inside the limiting protrusion. The anti-disengagement layer and the sliding layer are on the same plane, and the anti-disengagement layer is arranged close to the axis of the disc. A side hole is provided on the lower surface of the limiting protrusion. The side hole is located on one side of the positioning hole and extends to a position on one side inside the anti-disengagement layer. A rack is provided on the inner side of the insertion bar.

[0012] Preferably, an arc-shaped plate is fixedly connected between adjacent two sliders, and the diameter of the circle formed by all the arc-shaped plates is larger than the diameter of the circle formed by all the limiting protrusions.

[0013] Preferably, a magnetic block is provided on one side inside the chute. By rotating the slider, the insertion bar is pushed and inserted into the sliding layer, and the slider is adsorbed on the magnetic block.

[0014] Preferably, a cooling assembly is provided between the piston and the piston cylinder. The cooling assembly includes a cylinder arranged at one end of the piston. A piston body with an oil hole opened at its axial position is hermetically and slidably connected inside the cylinder. The end of the piston body is fixedly connected to the end cover opposite to one end of the piston. The oil hole on the piston body is communicated with an oil inlet pipe, and an oil outlet pipe is provided at the other end of the piston. A plurality of cooling channels are provided inside the piston, and the cooling channels are communicated with the cylinder and the oil outlet pipe.

[0015] Preferably, a plurality of overflow holes are provided at the root part between adjacent two meshing teeth, and each overflow hole is communicated with a cooling channel.

[0016] The advantages of the present invention are as follows: 1. In the present invention, the electro-hydraulic actuator adopts a modular design. The actuator adopts an internal limiting method, which can avoid the risk of leakage when the actuator adjusts the switch position. By adjusting the position of the limiting cam, the stroke adjustment of the actuator can be accurately achieved. The actuator adopts an integrated casting structure, with a beautiful and simple appearance, which is convenient for processing and assembly; the electric control unit can also adopt a modular and miniaturized design, with a compact structure, and can output a maximum pressure of 15 Mpa, greatly saving the installation space and adapting to many valves on the market.

[0017] 2. In the present invention, a replaceable adapter assembly is provided at the lower end of the gear shaft, that is, a adapter is provided, which can install different models or different specifications of adapters according to actual needs, and closely fit the torque input end of the valve stem with the secondary card slot on the adapter. When the gear shaft rotates subsequently, the valve stem rotates synchronously with the gear shaft, and the problem of the valve stem not rotating in place due to the clearance between the valve stem and the card slot is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the first perspective three-dimensional view of the electro-hydraulic actuator in the present invention; Figure 2 is the second perspective three-dimensional view of the electro-hydraulic actuator in the present invention; Figure 3 is the combined three-dimensional view of the gear shaft and the piston in the present invention; Figure 4 is the cross-sectional view of the piston cylinder in the present invention; Figure 5 is the three-dimensional view of the gear shaft in the present invention; Figure 6 is the combined three-dimensional view of the gear shaft and the adapter in the present invention; Figure 7 is the bottom view of the gear shaft in the present invention; Figure 8 is the cross-sectional view of the disc body in the present invention; Figure 9 is Figure 8 the partial enlarged view at A in Figure 10 is the first perspective three-dimensional view of the adapter in the present invention; Figure 11 is the second perspective three-dimensional view of the adapter in the present invention; Figure 12 is the combined three-dimensional view of the slider and the insert bar in the present invention; Figure 13 is the combined three-dimensional view of the arc plate and the slider in the present invention; Figure 14 is the combined three-dimensional view of the piston and the cooling component in the present invention; Figure 15Explosion diagram of the cooperation between the piston and the cooling component in the present invention; Figure 16 Schematic diagram of the distribution of the overflow holes on the piston in the present invention.

[0019] In the figure: 1, box body; 2, piston cylinder; 3, piston; 4, gear shaft; 5, columnar cylinder; 6, end cover; 7, oil passage; 8, meshing teeth; 9, card slot; 10, limiting cam; 11, limiting bolt; 12, graduated dial; 13, sealing cover; 14, adapter; 15, secondary card slot; 16, disc body; 17, limiting convex part; 18, concave part; 19, relief opening; 20, sliding groove; 21, slider; 22, insert bar; 23, sliding layer; 24, positioning pin; 25, toothed ring; 26, anti - detachment rod; 27, positioning hole; 28, anti - detachment layer; 29, side hole; 30, rack; 31, arc plate; 32, cylinder; 33, piston body; 34, inlet pipe; 35, outlet pipe; 36, cooling channel; 37, overflow hole; 38, electro - hydraulic oil electric component. Specific embodiments

[0020] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments. Embodiment 1

[0021] Refer to Figure 1 - Figure 4 , an electro - hydraulic actuator, including a box body 1, an end cover 6, a piston 3 and a gear shaft 4; the box body 1 includes a piston cylinder 2 for installing the piston 3 and a columnar cylinder 5 for installing the gear shaft 4, the axes of the piston cylinder 2 and the columnar cylinder 5 are perpendicular to each other, and one side of the columnar cylinder 5 communicates with the piston cylinder 2; two end covers 6 are respectively fixedly connected to both ends of the piston cylinder 2 by screws, and an oil passage 7 is opened inside each end cover 6, and the oil passage 7 inside the end cover 6 communicates with the oil passage 7 opened in the wall of the piston cylinder 2; both ends of the piston 3 are hermetically and slidably connected inside the piston cylinder 2, and a plurality of meshing teeth 8 are evenly opened on the surface of the piston 3 opposite to the columnar cylinder 5; the gear shaft 4 is rotatably connected inside the columnar cylinder 5, and the gear of the gear shaft 4 meshes with the meshing teeth 8; the lower end of the gear shaft 4 extends to the lower port position of the columnar cylinder 5, and a card slot 9 is opened on the lower end surface of the gear shaft 4, and the card slot 9 is used to cooperate with the torque input end of the external valve rod; The gear shaft 4 is fixedly connected with a limiting cam 10; Two limiting bolts 11 are symmetrically threadedly connected to the outer wall of the columnar cylinder 5, and the limiting bolts 11 are used to limit the rotation angle of the limiting cam 10 A graduated dial 12 is arranged at the center position of the upper end of the columnar cylinder 5, the upper end of the gear shaft 4 penetrates through the upper end of the columnar cylinder 5, and a sealing cover 13 is fixedly connected, and a pointer is arranged on the sealing cover 13, and the pointer cooperates with the graduated dial 12 to indicate the rotation angle of the gear shaft 4, which is convenient for on - site operators to identify and install and debug; As Figure 1 and Figure 2 shown, on one side of the box body 1, there is also a hydraulic oil electric component 38. The hydraulic oil electric component 38 includes an oil tank and an oil pump. The oil pump can inject the hydraulic oil in the oil tank into the inside of the oil circuit 7, and push the piston 3 to move inside the piston cylinder 2 through the pressure of the hydraulic oil; Sealing rings are arranged on the outer circles at both ends of the piston 3 to seal the gap between the piston 3 and the piston cylinder 2, and avoid the leakage of the hydraulic oil between the end cover 6 and the end of the piston 3 into the middle area of the piston cylinder 2. One is to cause pollution, and the other is that the hydraulic oil pressure is unstable; The specific working principle of this electro-hydraulic actuator is as follows: As Figure 4 shown, the oil pump injects the hydraulic oil into the oil circuit 7 on the left side of the piston cylinder 2. The hydraulic oil is injected into the cavity between the piston 3 and the end cover 6 along the oil circuit 7 on the left end cover 6. At this time, the hydraulic oil pushes the piston 3 to move linearly to the right. At the same time, the piston 3 drives the meshing teeth 8 to move linearly to the right. The meshing teeth 8 are meshed with the gear shaft 4. The gear shaft 4 rotates clockwise and drives the valve stem to rotate clockwise. The gear shaft 4 rotates 90 degrees clockwise (±5 degrees adjustable). The hydraulic oil in the cavity between the right end cover 6 and the piston 3 is pressed back to the oil tank through the oil circuit 7 on the right side of the piston cylinder 2, completing a one-way action and realizing the valve closing action; Similarly, the oil pump injects the hydraulic oil into the oil circuit 7 on the right side of the piston cylinder 2. The hydraulic oil is injected into the cavity between the piston 3 and the end cover 6 along the oil circuit 7 on the right end cover 6. At this time, the hydraulic oil pushes the piston 3 to move linearly to the left. At the same time, the piston 3 drives the meshing teeth 8 to move linearly to the left. The meshing teeth 8 are meshed with the gear shaft 4. The gear shaft 4 rotates counterclockwise and drives the valve stem to rotate counterclockwise. The gear shaft 4 rotates 90 degrees counterclockwise (±5 degrees adjustable). The hydraulic oil in the cavity between the left end cover 6 and the piston 3 is pressed back to the oil tank through the oil circuit 7 on the left side of the piston cylinder 2, completing a one-way action and realizing the valve opening action; When the valve switch action is not in place and the stroke needs to be adjusted, the stroke can be adjusted through the limit bolt 11. As Figure 1 shown, the left limit screw adjusts the valve opening position, and the right limit screw adjusts the closing position. For standard products, the stroke can be adjusted by ±5 degrees, that is, -5 degrees to +95 degrees; special strokes can be realized by customizing the limit cam 10; This electro-hydraulic actuator adopts a modular design. The actuator adopts an internal limiting method, which can avoid the risk of leakage when the actuator adjusts the switch position. By adjusting the position of the limit cam 10, the stroke adjustment of the actuator can be accurately realized. The actuator adopts an integrated casting structure, with a beautiful and concise appearance, which is convenient for processing and assembly; the electric control unit can also adopt a modular and miniaturized design, with a compact structure, and can output a maximum pressure of 15 Mpa, greatly saving the installation space and adapting to many valves on the market. Embodiment 2

[0022] Refer to Figure 5 - Figure 13 , compared with Embodiment 1, as another implementation mode of the present invention, and this Embodiment 2 is used to solve the problem of adapting the electro-hydraulic actuator to valve stems of many different specifications on the market, specifically as follows: A replaceable adapter assembly is provided at the lower end of the gear shaft 4, and the replaceable adapter assembly includes an adapter 14. One end of the adapter 14 is inserted into the card slot 9, and a secondary card slot 15 adapted to the torque input end of the external valve stem is provided at the other end of the adapter 14; A disc body 16 is radially provided on the outer circumference of the other end of the adapter 14, and a plurality of limiting protrusions 17 are provided on the outer circumference of the disc body 16; A recess 18 adapted to the disc body 16 and a relief opening 19 adapted to the shape of the limiting protrusion 17 are provided on the lower end surface of the gear shaft 4, and each relief opening 19 is provided on the periphery of the recess 18; When installing this electro-hydraulic actuator on a valve, the torque input end of the valve stem needs to be closely fitted with the card slot 9 to ensure the accuracy of the rotation angle of the valve stem; there are various valve stems of different specifications on the market, and a single-specification card slot 9 is difficult to adapt to many valve stems on the market. Therefore, a replaceable adapter assembly is provided in the card slot 9, and different models or specifications of adapters 14 can be installed according to actual needs. The specific operation of the adapter 14 is as follows: The adapter 14 is designed and processed according to the valve stems on the market. Before the operator installs the adapter 14 on the torque input end of the valve stem, first determine the specification of the adapter 14, then install the adapter 14 in the card slot 9, the disc body 16 is embedded in the recess 18, and the limiting protrusion 17 is embedded in the relief opening 19. Then install this electro-hydraulic actuator on the valve, and the torque input end of the valve stem is embedded in the secondary card slot 15. At this time, the torque input end of the valve stem is closely attached to the secondary card slot 15. When the gear shaft 4 rotates later, the valve stem rotates synchronously with the gear shaft 4, and the problem of the valve stem not rotating in place due to the clearance between the valve stem and the card slot 9 is avoided.

[0023] A plurality of arc-shaped sliding grooves 20 are circumferentially arranged at the edge position of the lower end surface of the gear shaft 4. A sliding block 21 is slidably connected in the sliding groove 20, and an inserting strip 22 is fixedly connected to the sliding block 21; a sliding layer 23 is provided on the outer side wall of the limiting protrusion 17. Rotate the sliding block 21, and the sliding block 21 pushes the inserting strip 22 to be inserted into the sliding layer 23; The adapter 14 is installed in the slot 9, and the matching limit convex is embedded in the relief opening 19. Then, the slider 21 is rotated. The slider 21 rotates around the axis of the gear shaft 4. At the same time, the slider 21 drives the insertion strip 22 to rotate. The end of the insertion strip 22 is inserted into the sliding layer 23. At this time, the entire adapter 14 is constrained in the slot 9, preventing the adapter 14 from disengaging from the slot 9 under its own gravity, and avoiding the adapter 14 from falling when the electro-hydraulic actuator is assembled on the valve.

[0024] A positioning pin 24 is rotatably connected in each relief opening 19. A toothed ring 25 is coaxially fixed on the outer circumference of the positioning pin 24. An anti-disengagement rod 26 is radially fixed on the outer circumference of the toothed ring 25. A positioning hole 27 adapted to the positioning pin 24 is provided on the limit convex portion 17. A fan-shaped anti-disengagement layer 28 is further provided inside the limit convex portion 17. The anti-disengagement layer 28 and the sliding layer 23 are on the same plane, and the anti-disengagement layer 28 is arranged close to the axis of the disk body 16. A side hole 29 is provided on the lower surface of the limit convex portion 17. The side hole 29 is located on one side of the positioning hole 27 and extends to a position on one side inside the anti-disengagement layer 28. A rack 30 is provided on the inner side of the insertion strip 22. The initial state of the positioning pin 24 is as Figure 8 and Figure 9 shown. The anti-disengagement rods 26 on the positioning pin 24 are all arranged in the same direction. Then, the adapter 14 is installed. The disk body 16 is embedded in the recess 18, the limit convex portion 17 is embedded in the relief opening 19, the positioning pin 24 is inserted along the positioning hole 27, and at the same time, the anti-disengagement rod 26 is inserted along the side hole 29. The anti-disengagement rod 26 is placed at the hinge joint of the anti-disengagement layer 28 and the side hole 29. Then, the slider 21 is pushed to rotate, the insertion rod is inserted into the sliding layer 23, and at the same time, the rack 30 on the insertion rod meshes with the toothed ring 25 and rubs the positioning pin 24 to rotate. The positioning pin 24 will drive the anti-disengagement rod 26 to rotate counterclockwise, so that the anti-disengagement rod 26 rotates deeper into the anti-disengagement layer 28. At this time, the anti-disengagement rod 26 further constrains the limit convex portion 17, thereby stably constraining the entire adapter 14.

[0025] An arc-shaped plate 31 is fixed between adjacent two sliders 21. The diameter of the circle formed by all the arc-shaped plates 31 is larger than the diameter of the circle formed by all the limit convex portions 17. Adjacent two sliders 21 are connected together by the arc-shaped plate 31. When one of the sliders 21 is pushed, all the sliders 21 will rotate synchronously. At the same time, all the insertion strips 22 are inserted into the sliding layer 23 synchronously. Similarly, when one of the sliders 21 is pushed back and reset, all the insertion strips 22 will also fall off the sliding layer 23 synchronously, and it is not necessary to execute each slider 21 one by one, which can improve the installation and disassembly efficiency of the adapter 14.

[0026] A magnetic block is provided on one side inside the chute 20. The slider 21 is rotated, the insertion strip 22 is pushed and inserted into the sliding layer 23, and the slider 21 is adsorbed on the magnetic block. When pushing the slider 21, the insert bar 22 is embedded in the sliding layer 23. At the same time, the end face of the slider 21 will also be adsorbed by the magnetic block, stabilizing the slider 21 itself and also stabilizing the insert bar 22 in the sliding layer 23, thereby fixing the entire adapter 14 in place. Embodiment III

[0027] Refer to Figure 14 - Figure 16 , compared with Embodiment I, as another implementation manner of the present invention, and this Embodiment III is used to solve the problem of heat dissipation and cooling during the frequent operation of the electro-hydraulic actuator, specifically as follows: A cooling assembly is provided between the piston 3 and the piston cylinder 2, and the cooling assembly includes a cylinder 32 provided at one end of the piston 3. A piston body 33 with an oil hole axially opened is hermetically and slidably connected in the cylinder 32. The end of the piston body 33 is fixedly connected to the end cover 6 opposite to one end of the piston 3. An oil inlet pipe 34 communicates with the oil hole on the piston body 33, and an oil outlet pipe 35 is provided at the other end of the piston 3; A plurality of cooling channels 36 are opened inside the piston 3, and the cooling channels 36 communicate the cylinder 32 and the oil outlet pipe 35; When the piston 3 frequently executes, that is, the piston 3 moves back and forth alternately in the piston cylinder 2, the friction between the end face of the piston 3 and the piston cylinder 2, as well as the friction between the gear shaft 4 and the meshing teeth 8, will generate a large amount of heat, which needs to be discharged in time to avoid affecting the smooth movement of the piston 3. Therefore, a cooling assembly is provided at the end of the piston 3; A one-way valve is provided on the oil inlet pipe 34 connected to the piston body 33, and this one-way valve allows only the external cooling oil to enter the piston body 33; a one-way valve is provided on the oil outlet pipe 35 connected to the other end of the piston 3, and this one-way valve allows only the cooling oil in the cooling channels 36 to be discharged; When the piston 3 moves to the right, the piston 3 will squeeze the piston body 33, and the coolant in the piston body 33 is pressed into the cooling channels 36. The heat absorbed by the cooling channels 36 exchanges heat with the cooling oil. At the same time, the coolant is discharged along the oil inlet pipe 34 connected to the other end of the piston 3. When the piston 3 moves to the left, the piston cylinder 2 sucks in the external cooling oil, and new coolant is replenished into the piston cylinder 2 again to prepare for the next cooling, controlling the temperature of the entire piston 3 within a relatively stable operating range, so that the piston 3 can operate continuously and stably.

[0028] 10. An electro-hydraulic actuator according to claim 9, wherein: a plurality of overflow holes 37 are opened at the root part between adjacent two meshing teeth 8, and each overflow hole 37 communicates with a cooling channel 36; The overflow hole 37 is communicated with the cooling channel 36, and the cooling oil in the cooling channel 36 will flow out along the overflow hole 37, and only a small amount of cooling oil flows out, which will neither affect the cooling of the piston 3 nor pollute the operating environment of the gear shaft 4. The cooling oil flows into the intersection of the gear shaft 4 and the meshing teeth 8 to lubricate and cool it. At the same time, the cooling oil will also flow into the rotating connection point between the gear shaft 4 and the cylindrical barrel 5 to lubricate and protect this position as well.

[0029] Working principle: The specific working principle of this electro-hydraulic actuator is as follows: As Figure 4 shown, the oil pump injects hydraulic oil into the oil passage 7 on the left side of the piston cylinder 2. The hydraulic oil is injected into the cavity between the piston 3 and the end cover 6 along the oil passage 7 on the left end cover 6. At this time, the hydraulic oil pushes the piston 3 to move linearly to the right. At the same time, the piston 3 drives the meshing teeth 8 to move linearly to the right. The meshing teeth 8 are engaged with the gear shaft 4, and the gear shaft 4 rotates clockwise and drives the valve stem to rotate clockwise. The gear shaft 4 rotates 90 degrees clockwise (±5 degrees adjustable). The hydraulic oil in the cavity between the right end cover 6 and the piston 3 is pressed back to the fuel tank through the oil passage 7 on the right side of the piston cylinder 2 to complete a one-way action and realize the valve closing action; Similarly, the oil pump injects hydraulic oil into the oil passage 7 on the right side of the piston cylinder 2. The hydraulic oil is injected into the cavity between the piston 3 and the end cover 6 along the oil passage 7 on the right end cover 6. At this time, the hydraulic oil pushes the piston 3 to move linearly to the left. At the same time, the piston 3 drives the meshing teeth 8 to move linearly to the left. The meshing teeth 8 are engaged with the gear shaft 4, and the gear shaft 4 rotates counterclockwise and drives the valve stem to rotate counterclockwise. The gear shaft 4 rotates 90 degrees counterclockwise (±5 degrees adjustable). The hydraulic oil in the cavity between the left end cover 6 and the piston 3 is pressed back to the fuel tank through the oil passage 7 on the left side of the piston cylinder 2 to complete a one-way action and realize the valve opening action; When the valve opening and closing actions are not in place and the stroke needs to be adjusted, the stroke can be adjusted through the limit bolt 11. As shown in the figure, the left limit screw adjusts the valve opening position, and the right limit screw adjusts the closing position. For standard products, the stroke can be adjusted by ±5 degrees, that is, -5 degrees to +95 degrees; special strokes can be achieved by customizing the limit cam 10.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An electro-hydraulic actuator, characterized in that: Comprising: A box body, which includes a piston cylinder for installing a piston and a columnar cylinder for installing a gear shaft. The axes of the piston cylinder and the columnar cylinder are vertically arranged, and one side of the columnar cylinder communicates with the piston cylinder; End caps, two of which are respectively fixedly connected to both ends of the piston cylinder by screws. An oil passage is provided inside each end cap, and the oil passage inside the end cap communicates with the oil passage provided in the piston cylinder wall; A piston, the two ends of which are hermetically and slidably connected inside the piston cylinder, and a plurality of meshing teeth are evenly provided on the surface of the piston opposite to the columnar cylinder; A gear shaft, which is rotatably connected inside the columnar cylinder. The gear of the gear shaft meshes with the meshing teeth; the lower end of the gear shaft extends to the lower port position of the columnar cylinder, and a clamping groove is provided on the lower end surface of the gear shaft for cooperating with the torque input end of an external valve rod.

2. The electro-hydraulic actuator according to claim 1, characterized in that: A limiting cam is fixedly connected to the gear shaft; Two limiting bolts are symmetrically threadedly connected to the outer wall of the columnar cylinder, and the limiting bolts are used to limit the rotation angle of the limiting cam.

3. An electro-hydraulic actuator according to claim 2, characterized in that: A scale disk is provided at the center position of the upper end of the columnar cylinder. The upper end of the gear shaft penetrates through the upper end of the columnar cylinder and is fixedly connected with a sealing cover. A pointer is provided on the sealing cover, and the pointer cooperates with the scale disk to indicate the rotation angle of the gear shaft.

4. The electro-hydraulic actuator according to claim 3, characterized in that: A replaceable adapter assembly is provided at the lower end of the gear shaft, and the replaceable adapter assembly includes a connector. One end of the connector is inserted into the clamping groove, and the other end of the connector is provided with a secondary clamping groove adapted to the torque input end of an external valve rod; A disk body is radially provided on the outer circle of the other end of the connector, and a plurality of limiting convex parts are provided on the outer circle of the disk body; A concave part adapted to the disk body and a relief opening adapted to the shape of the limiting convex part are provided on the lower end surface of the gear shaft.

5. An electro-hydraulic actuator according to claim 4, characterized in that: A plurality of arc-shaped chutes are circumferentially arranged at the edge position of the lower end surface of the gear shaft. Sliders are slidably connected in the chutes, and insertion bars are fixedly connected to the sliders; a sliding layer is provided on the outer side wall of the limiting convex part. By rotating the slider, the insertion bar is pushed and inserted into the sliding layer.

6. An electro-hydraulic actuator according to claim 5, characterized in that: A positioning pin is rotatably connected in each relief opening. A tooth ring is coaxially fixedly connected to the outer circle of the positioning pin, and an anti-detachment rod is radially fixedly connected to the outer circle of the tooth ring; A positioning hole adapted to the positioning pin is provided on the limiting convex part, and a fan-shaped anti-detachment layer is further provided inside the limiting convex part. The anti-detachment layer and the sliding layer are on the same plane, and the anti-detachment layer is arranged close to the axis of the disk body; A side hole is provided on the lower surface of the limiting convex part. The side hole is located on one side of the positioning hole and extends to one side position inside the anti-detachment layer; a rack is provided on the inner side of the insertion bar.

7. An electro-hydraulic actuator according to claim 5, characterized in that: An arc-shaped plate is fixedly connected between adjacent two sliders, and the diameter of the circle formed by all the arc-shaped plates is larger than the diameter of the circle formed by all the limiting convex parts.

8. An electro-hydraulic actuator according to claim 5, characterized in that: A magnetic block is provided on one side inside the chute. By rotating the slider, the insertion bar is pushed and inserted into the sliding layer, and the slider is adsorbed on the magnetic block.

9. An electro-hydraulic actuator according to claim 1, characterized in that: A cooling assembly is provided between the piston and the piston cylinder, and the cooling assembly includes a cylinder provided at one end of the piston. A piston body with an oil hole provided at the axis position is hermetically and slidably connected inside the cylinder. The end of the piston body is fixedly connected to the end cap opposite to one end of the piston. An oil inlet pipe is communicated with the oil hole on the piston body, and an oil outlet pipe is provided at the other end of the piston; A plurality of cooling channels are provided inside the piston, and the cooling channels communicate the cylinder and the oil outlet pipe.

10. An electro-hydraulic actuator according to claim 9, characterized in that: A plurality of overflow holes are provided at the tooth root parts between adjacent two meshing teeth, and each overflow hole communicates with a cooling channel.

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