Electro-hydraulic driver

Abstract

An electro-hydraulic driver comprises a hydraulic cylinder and an oil storage cylinder, a piston is assembled in the hydraulic cylinder, the piston is connected with a hydraulic rod, and a cavity in the hydraulic cylinder is divided into a rodless cavity and a rod cavity by the piston. An oil storage cavity is formed in the side face of the hydraulic cylinder, a containing cavity communicating with the oil storage cavity is formed in the oil storage cylinder, and a valve seat is assembled in the containing cavity. A flow channel structure is arranged in the valve seat and comprises an extending flow channel, a retracting flow channel, a pump cavity and an oil supplementing flow channel. And pressure maintaining assemblies and oil outlet one-way valves are assembled in the extending flow channel and the retracting flow channel. The pump cavity is communicated with the extending flow channel and the retracting flow channel, and an oil pumping assembly is assembled in the pump cavity and driven by a motor fixed to the oil storage cylinder. The oil supplementing flow channel communicates with the pump cavity and the containing cavity. The oil pumping assembly, the flow channel structure and other components and structures are integrated in the valve seat, the overall layout is optimized, the structure is more compact and reasonable, the sealing performance and operation stability of a system are enhanced, the service life of equipment is prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of electro-hydraulic drive actuators, and specifically relates to an electro-hydraulic actuator. Background Technology

[0002] An electro-hydraulic actuator is a device that uses electrical energy to drive a hydraulic system, thereby achieving mechanical motion. It is widely used in industrial automation, construction machinery, aerospace, and other fields. It typically consists of key components such as a hydraulic cylinder, a reservoir, and a pump assembly. The hydraulic cylinder, as the actuator, contains a piston that is connected to an external mechanical device via a hydraulic rod. Hydraulic oil enters the hydraulic cylinder and pushes the piston, thus controlling the external mechanical device. The pump assembly and flow channel structure are the core of the hydraulic system, responsible for delivering hydraulic oil from the reservoir to the hydraulic cylinder and precisely controlling the piston's movement by controlling the flow direction and pressure of the oil.

[0003] Existing electro-hydraulic actuators typically distribute the pump assembly, valves, and flow channel structures across multiple mechanisms such as the pump and manifold. This layout has several drawbacks. First, the dispersed components result in a less compact overall structure, increasing manufacturing and assembly complexity and reducing production efficiency. Second, the numerous connections between components increase the difficulty of sealing, making leaks more likely and reducing the system's sealing performance. This affects the equipment's operational stability, may even lead to malfunctions, and increases maintenance frequency and costs.

[0004] Therefore, based on some of the situations in the prior art described above, this application has made further designs and improvements. Utility Model Content

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution.

[0006] An electro-hydraulic actuator includes a hydraulic cylinder and an oil reservoir. A piston is mounted inside the hydraulic cylinder, and a hydraulic rod is connected to the piston. The piston divides the cavity within the hydraulic cylinder into a rodless cavity and a rod cavity. An oil reservoir is located on the side of the hydraulic cylinder, and a receiving cavity communicating with the oil reservoir is located inside the oil reservoir. A valve seat is mounted within the receiving cavity. The valve seat has a flow channel structure, which includes an extension flow channel, a retraction flow channel, a pump chamber, and a replenishment flow channel.

[0007] The extending flow channel communicates with the rodless chamber. An extending assembly cavity is located at the end of the extending flow channel connecting to the rodless chamber, and a pressure-holding assembly is installed within the extending assembly cavity. An extending oil outlet channel, connecting to the receiving chamber, is connected to the extending flow channel and is equipped with an oil outlet check valve. The retracting flow channel communicates with the rod chamber. A retracting assembly cavity is located at the end of the retracting flow channel connecting to the rod chamber, and a pressure-holding assembly is installed within the retracting assembly cavity. A retracting oil outlet channel, connecting to the receiving chamber, is connected to the retracting flow channel and is equipped with an oil outlet check valve. The pump chamber connects the extending flow channel and the retracting flow channel, and a pumping assembly is installed within the pump chamber. The pumping assembly is driven by a motor fixed to the oil reservoir. A replenishment flow channel connects the pump chamber and the receiving chamber.

[0008] Furthermore, the pressure-holding assembly includes a pressure-holding valve with a cavity. A pressure-holding valve core and a pressure-holding spring are assembled within the cavity. A first oil port and a second oil port are located at both ends of the cavity along the axial direction. The first oil port is near the flow channel structure, and the second oil port is near the hydraulic cylinder. A gap for oil flow exists between the side of the pressure-holding valve core and the inner wall of the cavity. When the hydraulic pressure in the hydraulic cylinder is greater than the hydraulic pressure in the flow channel structure, the pressure-holding valve closes, and the end face of the pressure-holding valve core blocks the first oil port under the action of the pressure-holding spring. When the hydraulic pressure in the flow channel structure is greater than the hydraulic pressure in the hydraulic cylinder, the pressure-holding valve opens, the pressure-holding valve core is pushed upwards, and oil can pass through the first oil port.

[0009] Furthermore, the pressure holding assembly also includes an auxiliary valve; the auxiliary valve is provided with an axially penetrating third oil port, the auxiliary valve is located on the side of the pressure holding valve with the first oil port, and is connected to the pressure holding valve by an auxiliary spring; a baffle that blocks the third oil port is mounted on the other side of the auxiliary valve; an auxiliary protrusion is provided on the side of the auxiliary valve facing the pressure holding valve, and a pressure holding protrusion is provided on the pressure holding valve core; when the pressure holding valve is in the closed state, the pressure holding protrusion extends out from the first oil port.

[0010] Furthermore, the oil outlet check valve includes an oil outlet check valve plate, an oil outlet check valve block, and an oil outlet check spring assembled in sequence. There is a gap for oil flow between the side of the oil outlet check valve plate and the inner wall of the oil outlet passage. The oil outlet check valve block is provided with a through groove for oil flow. One end of the oil outlet check spring abuts against the inner wall of the receiving cavity, and the other end abuts against the oil outlet check valve block.

[0011] Furthermore, the oil pump assembly includes a pair of meshing oil pump gears and a drive gear driven by a motor, the drive gear meshing with one of the oil pump gears; the pump chamber includes a main chamber accommodating the oil pump gears and a side chamber accommodating the drive gear; there are two oil replenishment channels, one connecting to the pump chamber and the other connecting to the side chamber.

[0012] Furthermore, the valve seat is equipped with a manual relief valve and a relief check valve. The manual relief valve, in conjunction with the relief check valve, can relieve pressure on the hydraulic cylinder. The manual relief valve includes a control rod, a pressure relief rod, and a manual relief spring. The pressure relief rod is mounted at the bottom of the control rod, and the manual relief spring helps the control rod to reset. A limit pin is mounted on the control rod, and a switching groove that cooperates with the limit pin is provided on the housing of the oil reservoir. The groove depth at one end of the switching groove is greater than the groove depth at the other end, and the groove depths at both ends correspond to the closed and open states of the manual relief valve, respectively. The valve seat is provided with a manual relief groove that connects to the receiving cavity, and the pressure relief rod is located in the manual relief groove. A relief control groove is provided on the hydraulic cylinder corresponding to the manual relief groove, and the pressure relief check valve is located in the relief control groove. When the manual relief valve is opened, the pressure relief rod descends and opens the relief check valve, allowing the oil in the hydraulic cylinder cavity to enter the receiving cavity through the manual relief groove.

[0013] Furthermore, the valve seat is also equipped with an automatic relief valve, which includes a rodless relief valve and a rod relief valve. The valve seat has a relief channel for assembling the automatic relief valve, which is divided into a rodless relief channel connecting to the rodless chamber and a rod relief channel connecting to the rod chamber, corresponding to the rodless and rod relief valves, respectively. The automatic relief valve includes a push rod and an automatic relief spring. A spherical plug is provided at the bottom of the push rod. One end of the automatic relief spring abuts against the inner wall of the receiving cavity, and the other end abuts against the push rod. Under the action of the automatic relief spring, the spherical plug blocks the relief channel. When the oil pressure in the rod chamber or rodless chamber exceeds a certain value, the oil pressure pushes the push rod upward, and the oil flows through the relief channel into the receiving cavity.

[0014] Furthermore, the valve seat is also provided with a pressure relief channel, which is connected to the extended assembly cavity and the retracted assembly cavity. The pressure relief channel is equipped with a pressure relief valve, which can be manually opened to relieve pressure on the channel structure.

[0015] Furthermore, a through pipe is installed inside the cavity of the hydraulic cylinder, and the piston is installed inside the through pipe. There is a space between the through pipe and the inner wall of the cavity. A spacer ring is installed on the outer wall of the through pipe. The spacer ring divides the space into a rodless connection space that connects to the rodless cavity and a rod connection space that connects to the rod cavity. The extended flow channel connects to the rodless connection space, and the retracted flow channel connects to the rod connection space.

[0016] Compared with the prior art, this application has the following beneficial technical effects: by integrating components and structures such as the pump oil assembly and flow channel structure into the valve seat, the overall layout is optimized, making the structure more compact and reasonable, enhancing the sealing performance and operational stability of the system, extending the service life of the equipment, and reducing maintenance costs. Attached Figure Description

[0017] Figure 1 This is a 3D view of the electro-hydraulic actuator.

[0018] Figure 2This is an exploded view of an electro-hydraulic actuator.

[0019] Figure 3 This is a top view of the electro-hydraulic actuator.

[0020] Figure 4 for Figure 3 Sectional view at point AA.

[0021] Figure 5 for Figure 4 A magnified view of a section at point B.

[0022] Figure 6 This is an assembly drawing of the motor, valve seat, and hydraulic cylinder.

[0023] Figure 7 A three-dimensional sectional view of the valve seat and hydraulic cylinder Figure 1 .

[0024] Figure 8 A three-dimensional sectional view of the valve seat and hydraulic cylinder Figure 2 .

[0025] Figure 9 A three-dimensional sectional view of the valve seat and hydraulic cylinder Figure 3 .

[0026] Figure 10 This is a three-dimensional view of the oil reservoir housing.

[0027] Figure 11 This is a layout diagram of the flow channel structure.

[0028] Figure 12 This is a top view of the valve seat.

[0029] Figure 13 This is an assembly drawing of the valve plate and related valve bodies.

[0030] Figure 14 This is a 3D view of the valve plate.

[0031] Figure 15 This is a structural diagram of the installation section.

[0032] Figure 16 This is a cross-sectional view of the valve seat at the pressure-holding assembly.

[0033] Figure 17 This is an exploded view of the pressure holding assembly.

[0034] Figure 18 This is an exploded view of the oil outlet check valve.

[0035] The following is an explanation of the reference numerals in the attached figures:

[0036] 100. Hydraulic cylinder; 101. Rodless chamber; 102. Rod chamber; 103. Rodless connection space; 104. Rod connection space; 105. Oil reservoir; 106. Drainage control groove; 110. Piston; 120. Hydraulic rod; 130. Through pipe; 140. Spacer ring;

[0037] 200, Oil reservoir; 201, Receiving cavity; 202, Switching slide; 210, Motor; 211, Drive shaft; 220, Oil pump assembly; 221, Oil pump gear; 222, Drive gear;

[0038] 300. Flow channel structure; 310. Extended flow channel; 311. Extended assembly cavity; 320. Retracted flow channel; 321. Retracted assembly cavity; 330. Pump cavity; 331. Main cavity; 332. Side cavity; 340. Oil replenishment flow channel; 350. Extended oil outlet channel; 351. Retracted oil outlet channel; 360. Pressure relief flow channel; 370. Rodless relief flow channel; 371. Rod-type relief flow channel; 380. Manual relief groove;

[0039] 400, Valve seat; 410, Mounting part; 420, Valve plate; 430, Bearing; 440, Oil outlet check valve; 441, Oil outlet check valve plate; 442, Oil outlet check valve block; 443, Through groove; 444, Oil outlet check spring; 450, Flow channel pressure relief valve; 460, Rodless relief valve; 461, Rod-type relief valve; 462, Push rod; 463, Automatic relief spring; 470, Manual relief valve; 471, Control lever; 472, Pressure relief lever; 473, Manual relief spring; 474, Limit pin; 480, Relief check valve;

[0040] 500, Pressure holding assembly; 510, Pressure holding valve; 511, Cavity; 512, First oil port; 513, Second oil port; 520, Pressure holding valve core; 521, Pressure holding protrusion; 530, Pressure holding spring; 540, Auxiliary valve; 541, Third oil port; 542, Auxiliary protrusion; 550, Auxiliary spring; 560, Baffle. Detailed Implementation

[0041] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0042] In the following embodiments, the same or similar reference numerals denote the same or similar components or components with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0043] In the description of this utility model, it should be understood that the terms such as center, longitudinal, transverse, length, width, thickness, upper, lower, front, back, left, right, vertical, horizontal, top, bottom, inner, outer, clockwise, and counterclockwise, indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description; therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features shown. In the description of this utility model, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0044] refer to Figures 1 to 18 An electro-hydraulic actuator includes a hydraulic cylinder 100, an oil reservoir 200, and a flow channel structure 300. The flow channel structure 300 includes an extending flow channel 310, a retracting flow channel 320, and a pump chamber 330 connecting the extending flow channel 310 and the retracting flow channel 320. An oil pump assembly 220 is installed in the pump chamber 330 and is driven by a motor 210 fixed to the oil reservoir 200. A piston 110 is installed in the hydraulic cylinder 100, and a hydraulic rod 120 is connected to the piston 110. The piston 110 divides the cavity within the hydraulic cylinder 100 into a rodless cavity 101 and a rod cavity 102. The extending flow channel 310 communicates with the rodless cavity 101, and the retracting flow channel 320 communicates with the rod cavity 102. The oil reservoir 200 is located on the side of the hydraulic cylinder 100, forming a T-shaped layout. The hydraulic cylinder 100 has a mounting part 410 and an oil storage chamber 105 on the side of the cylinder body. A valve plate 420 is mounted on the mounting part 410. The mounting part 410 and the valve plate 420 are assembled to form a valve seat 400. A flow channel structure 300 is disposed in the valve seat 400. The oil storage cylinder 200 has a receiving cavity 201 for accommodating the valve seat 400. The oil storage chamber 105 is connected to the receiving cavity 201.

[0045] Compared with existing technologies, the hydraulic cylinder 100 and oil reservoir 200 in this application adopt a T-shaped layout design. Compared with the parallel design of the hydraulic cylinder 100 and oil reservoir 200, the structural strength and stability are greatly improved, avoiding problems such as leakage points in the flow channel structure 300 and easy breakage at the parallel connection due to vibration, external forces, etc. Moreover, the T-shaped layout design greatly shortens the flow channel length and significantly optimizes the flow channel structure 300, improving the response speed. In addition, thanks to the T-shaped layout, this application integrates components and structures such as the pump assembly 220 and the flow channel structure 300 into the valve seat 400, greatly simplifying the overall structure of the control device and reducing costs.

[0046] Example 1

[0047] As one embodiment of this application, reference is made to Figure 11The extended flow channel 310, connected to the rodless cavity 101, has an extended assembly cavity 311 at one end, and the retractable flow channel 320, connected to the rod cavity 102, has a retractable assembly cavity 321 at one end. Both the extended assembly cavity 311 and the retractable assembly cavity 321 are equipped with pressure-holding components 500. When the hydraulic pressure in the flow channel structure 300 is greater than the hydraulic pressure in the hydraulic cylinder 100 (such as during system oil replenishment or pressure fluctuations), the pressure-holding component 500 opens to ensure balanced oil pressure. When the hydraulic pressure in the hydraulic cylinder 100 is greater than the hydraulic pressure in the flow channel structure 300 (such as during the static pressure-holding phase of the actuator), the pressure-holding component 500 closes to prevent oil from flowing back from the hydraulic cylinder 100 to the reservoir 200, thus keeping the hydraulic cylinder 100 in a holding state.

[0048] For details, please refer to Figure 16 and Figure 17 The pressure-holding assembly 500 includes a pressure-holding valve 510, which has a cavity 511. A pressure-holding valve core 520 and a pressure-holding spring 530 are assembled within the cavity 511. A first oil port 512 and a second oil port 513 are provided at both ends of the cavity 511 along the axial direction. The first oil port 512 is near the valve plate 420, and the second oil port 513 is near the hydraulic cylinder 100. A gap for oil flow exists between the side of the pressure-holding valve core 520 and the inner wall of the cavity 511. The end face of the pressure-holding valve core 520 blocks the first oil port 512 under the action of the pressure-holding spring 530.

[0049] Furthermore, the pressure-holding assembly 500 also includes an auxiliary valve 540, which assists in opening the pressure-holding valve 510. The auxiliary valve 540 has an axially extending third oil port 541. The auxiliary valve 540 is located on the side of the pressure-holding valve 510 with the first oil port 512 and is connected to the pressure-holding valve 510 via an auxiliary spring 550. A baffle 560 is fitted on the other side of the auxiliary valve 540 to block the third oil port 541. An auxiliary protrusion 542 is provided on the side of the auxiliary valve 540 facing the pressure-holding valve 510, and a pressure-holding protrusion 521 is provided on the pressure-holding valve core 520. When the pressure-holding valve 510 is closed, the pressure-holding protrusion 521 extends from the first oil port 512. When the hydraulic pressure in the flow channel structure 300 is greater than the hydraulic pressure in the hydraulic cylinder 100, the oil pressure drives the auxiliary valve 540 to move toward the pressure holding valve 510, and the auxiliary protrusion 542 pushes against the pressure holding protrusion 521 and moves backward to open the pressure holding valve 510.

[0050] To accommodate the design of the valve seat 400 and reduce the distance between the protruding assembly cavity 311 and the retracting assembly cavity 321, refer to... Figure 4 and Figure 5The hydraulic cylinder 100 has a through pipe 130 installed inside its cavity. The piston 110 is installed inside the through pipe 130. There is a space between the through pipe 130 and the inner wall of the cavity. A spacer ring 140 is installed on the outer wall of the through pipe 130. The spacer ring 140 divides the space into a rodless connection space 103 that connects to the rodless cavity 101 and a rod connection space 104 that connects to the rod cavity 102. The extended flow channel 310 connects to the rodless connection space 103, and the retracted flow channel 320 connects to the rod connection space 104.

[0051] The working principle of the pressure-holding assembly 500 is further explained below using the example of an electro-hydraulic actuator performing an extension action: The motor 210 drives the oil pump assembly 220. Oil first enters the retraction channel 320 from the receiving chamber 201 via the replenishment channel 340 and the pump chamber 330, and is then pumped by the oil pump assembly 220 to the extension channel 310. During this process, the oil pressure in the retraction channel 320 is greater than the oil pressure in the rod chamber 102, and the pressure-holding valve 510 in the retraction assembly chamber 321 opens. The oil pressure in the extension channel 310 is greater than the oil pressure in the rodless chamber 101, and the pressure-holding valve 510 in the extension assembly chamber 311 opens. At this time, both the extension channel 310 and the retraction channel 320 are connected. Oil in the extension channel 310 can smoothly enter the rodless chamber 101, and oil in the rod chamber 102 can smoothly flow back to the retraction channel 320, causing the hydraulic cylinder 100 to extend.

[0052] Example 2

[0053] As one embodiment of this application, the flow channel structure 300 further includes an oil replenishment flow channel 340 and an oil outlet channel.

[0054] The oil replenishment channel 340 connects the pump chamber 330 and the receiving chamber 201. Further, refer to... Figure 13 The oil pump assembly 220 includes a pair of meshing pump gears 221 and a drive gear 222 driven by a motor 210, the drive gear 222 meshing with one of the pump gears 221. The pump chamber 330 includes a main chamber 331 accommodating the pump gears 221 and a side chamber 332 accommodating the drive gear 222. There are two oil replenishment channels 340, one connecting to the pump chamber 330 and the other connecting to the side chamber 332. The oil replenishment channels 340 ensure that the oil in the pump chamber 330 is always properly filled, improving pumping efficiency and stability.

[0055] In this embodiment, a drive shaft 211 is provided on the motor 210, a drive gear 222 is provided on the drive shaft 211, and a drive groove is provided on the valve seat 400 for the drive shaft 211 to extend into. A bearing 430 is mounted on the drive groove and sleeved on the drive shaft 211. The bearing 430 can reduce the friction between the drive shaft 211 and the valve seat 400, improve the smoothness of transmission, and ensure more stable meshing between the drive gear 222 and the pump gear 221.

[0056] The oil outlet includes an extending oil outlet 350 and a retracting oil outlet 351. The extending oil outlet 350 connects to the extending flow channel 310 and the receiving cavity 201, while the retracting oil outlet 351 connects to the retracting flow channel 320 and the receiving cavity 201. Both the extending oil outlet 350 and the retracting oil outlet 351 are equipped with an oil outlet check valve 440 that allows oil to flow from the flow channel structure 300 to the receiving cavity 201. This ensures that the oil can only flow unidirectionally from the flow channel structure 300 to the receiving cavity 201, preventing backflow and thus ensuring stable system pressure and orderly oil flow.

[0057] Specifically, refer to Figure 8 and Figure 17 The oil outlet check valve 440 includes an oil outlet check valve plate 441, an oil outlet check valve block 442, and an oil outlet check spring 444, which are assembled in sequence. There is a gap between the side of the oil outlet check valve plate 441 and the inner wall of the oil outlet passage for oil flow. The oil outlet check valve block 442 is provided with a through groove 443 for oil flow. One end of the oil outlet check spring 444 abuts against the inner wall of the receiving cavity 201, and the other end abuts against the oil outlet check valve block 442. Under the action of the oil outlet check spring 444, the oil outlet check valve plate 441 blocks the oil outlet of the oil passage. When the oil pressure in the flow channel structure 300 exceeds a certain value, the oil pressure pushes the oil outlet check valve plate 441 upwards, and the oil flows through the gap between the side of the oil outlet check valve plate 441 and the inner wall of the oil outlet passage, and through the through groove 443 on the oil outlet check valve block 442, before entering the receiving cavity 201.

[0058] Example 3

[0059] As one embodiment of this application, the flow channel structure 300 further includes a pressure relief flow channel 360. The pressure relief flow channel 360 is disposed on the valve plate 420 and communicates with the extended assembly cavity 311 and the retracted assembly cavity 321. A flow channel pressure relief valve 450 is installed within the pressure relief flow channel 360. Pressure relief in the flow channel structure 300 can be relieved by manually opening the flow channel pressure relief valve 450. The flow channel pressure relief valve 450 can quickly release pressure within the system in emergency situations, improving system safety and operability. The flow channel pressure relief valve 450 is a spherical plug, a conventional technology, and will not be described in detail here.

[0060] Example 4

[0061] As one embodiment of this application, the valve seat 400 is also equipped with an automatic relief valve, which includes a rodless relief valve 460 and a rod relief valve 461. The rodless relief valve 460 is used to automatically relieve pressure in the rodless chamber 101, and the rod relief valve 461 is used to automatically relieve pressure in the rod chamber 102. The valve seat 400 is provided with a relief channel for assembling the automatic relief valve. The relief channel is divided into a rodless relief channel 370 and a rod relief channel 371 corresponding to the rodless relief valve 460 and the rod relief valve 461, respectively. The rodless relief channel 370 connects to the rodless chamber 101, and the rod relief channel 371 connects to the rod chamber 102.

[0062] refer to Figure 7 The automatic relief valve includes a rod 462 and an automatic relief spring 463. A spherical plug is located at the bottom of the rod 462. One end of the automatic relief spring 463 rests against the inner wall of the receiving cavity 201, and the other end rests against the rod 462. Under the action of the automatic relief spring 463, the spherical plug blocks the relief passage. When the oil pressure in the rod chamber 102 or the rodless chamber 101 exceeds a certain value, the oil pressure pushes the rod 462 upwards, and the oil flows through the relief passage into the receiving cavity 201.

[0063] Example 5

[0064] As one embodiment of this application, a manual relief valve 470 and two sets of relief check valves 480 are mounted on the valve seat 400. (See reference) Figure 9The manual relief valve 470 includes a control lever 471, two sets of pressure relief levers 472, and a manual relief spring 473. The top of the control lever 471 protrudes from the surface of the oil reservoir 200 for easy control. The two sets of pressure relief levers 472 are abutted against the bottom of the control lever 471. The manual relief spring 473 helps the control lever 471 to reset. A limit pin 474 is mounted on the control lever 471. The housing of the oil reservoir 200 is provided with a switching groove 202 that cooperates with the limit pin 474. The groove depth at one end of the switching groove 202 is greater than the groove depth at the other end, and the groove depths at both ends correspond to the closed and open states of the manual relief valve 470, respectively. The valve plate 420 is provided with two sets of manual relief grooves 380 that communicate with the receiving cavity 201. The two sets of pressure relief levers 472 are respectively mounted in the two sets of manual relief grooves 380. The mounting section 410 is equipped with a discharge control groove 106 corresponding to the manual discharge groove 380, and a pressure relief check valve is installed in the discharge control groove 106. One set of discharge control grooves 106 connects to the rodless chamber 101, and the other set connects to the rod chamber 102. When the manual discharge valve 470 is opened, the pressure relief rod 472 descends and opens the discharge check valve 480, and the oil in the hydraulic cylinder 100 chamber enters the receiving chamber 201 through the manual discharge groove 380. In this embodiment, the discharge check valve 480 adopts a ball plug combined with a discharge check spring design, which is a conventional technology and will not be described in detail here. In case of emergency or system failure (such as the hydraulic rod 120 failing to extend or retract, or the automatic discharge valve malfunctioning), the pressure can be quickly released by operating the manual discharge valve 470 to open the discharge check valve 480, causing the hydraulic rod 120 to retract to its initial position, thus improving the safety and reliability of the control device.

[0065] The scope of protection of this utility model includes, but is not limited to, the above embodiments. The scope of protection of this utility model is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art shall fall within the scope of protection of this utility model.

Claims

1. An electro-hydraulic actuator, comprising a hydraulic cylinder (100) and an oil reservoir (200), wherein a piston (110) is assembled inside the hydraulic cylinder (100), and a hydraulic rod (120) is connected to the piston (110), the piston (110) dividing the cavity inside the hydraulic cylinder (100) into a rodless cavity (101) and a rod cavity (102); characterized in that, The hydraulic cylinder (100) has an oil storage chamber (105) on its side, and the oil storage cylinder (200) has a receiving cavity (201) communicating with the oil storage chamber (105). A valve seat (400) is assembled in the receiving cavity (201). A flow channel structure (300) is provided in the valve seat (400). The flow channel structure (300) includes: An extension flow channel (310) is connected to a rodless cavity (101). An extension assembly cavity (311) is provided at one end of the extension flow channel (310) that is connected to the rodless cavity (101). A pressure holding component (500) is installed in the extension assembly cavity (311). An extension oil outlet channel (350) that is connected to the receiving cavity (201) is connected to the extension flow channel (310). An oil outlet check valve (440) is installed in the extension oil outlet channel (350). The retraction channel (320) is connected to the rod chamber (102). A retraction assembly chamber (321) is provided at one end of the retraction channel (320) connected to the rod chamber (102). A pressure holding component (500) is installed in the retraction assembly chamber (321). A retraction oil outlet channel (351) is connected to the retraction channel (320) and communicates with the receiving chamber (201). An oil outlet check valve (440) is installed in the retraction oil outlet channel (351). The pump chamber (330) is connected to the extension flow channel (310) and the retraction flow channel (320). The pump chamber (330) is equipped with an oil pump assembly (220), which is driven by a motor (210) fixed on the oil reservoir (200). The oil replenishment channel (340) connects the pump chamber (330) and the receiving chamber (201).

2. The electro-hydraulic actuator according to claim 1, characterized in that, The pressure holding assembly (500) includes a pressure holding valve (510), which has a cavity (511). A pressure holding valve core (520) and a pressure holding spring (530) are assembled in the cavity (511). A first oil port (512) and a second oil port (513) are provided at both ends of the cavity (511) along the axial direction. The first oil port (512) is close to the flow channel structure (300), and the second oil port (513) is close to the hydraulic cylinder (100). There is a gap between the side of the pressure holding valve core (520) and the inner wall of the cavity (511) for oil flow. When the hydraulic pressure in the hydraulic cylinder (100) is greater than the hydraulic pressure in the flow channel structure (300), the pressure holding valve (510) closes, and the end face of the pressure holding valve core (520) blocks the first oil port (512) under the action of the pressure holding spring (530); when the hydraulic pressure in the flow channel structure (300) is greater than the hydraulic pressure in the hydraulic cylinder (100), the pressure holding valve (510) opens, the pressure holding valve core (520) is pushed up, and the oil can pass through the first oil port (512).

3. An electro-hydraulic actuator according to claim 2, characterized in that, The pressure holding assembly (500) also includes an auxiliary valve (540); the auxiliary valve (540) is provided with an axially penetrating third oil port (541), the auxiliary valve (540) is located on the side of the pressure holding valve (510) with the first oil port (512), and is connected to the pressure holding valve (510) by an auxiliary spring (550); the other side of the auxiliary valve (540) is equipped with a baffle (560) that blocks the third oil port (541); the auxiliary valve (540) is provided with an auxiliary protrusion (542) on the side facing the pressure holding valve (510), and a pressure holding protrusion (521) is provided on the pressure holding valve core (520). When the pressure holding valve (510) is in the closed state, the pressure holding protrusion (521) extends out from the first oil port (512).

4. An electro-hydraulic actuator according to claim 1, characterized in that, The oil outlet check valve (440) includes an oil outlet check valve plate (441), an oil outlet check valve block (442), and an oil outlet check spring (444) assembled in sequence. There is a gap between the side of the oil outlet check valve plate (441) and the inner wall of the oil outlet passage for oil flow. The oil outlet check valve block (442) is provided with a through groove (443) for oil flow. One end of the oil outlet check spring (444) abuts against the inner wall of the receiving cavity (201), and the other end abuts against the oil outlet check valve block (442).

5. An electro-hydraulic actuator according to claim 1, characterized in that, The oil pump assembly (220) includes a pair of meshing oil pump gears (221) and a drive gear (222) driven by a motor (210), the drive gear (222) meshing with one of the oil pump gears (221); The pump chamber (330) includes a main chamber (331) that accommodates the pump gear (221) and a side chamber (332) that accommodates the drive gear (222); there are two oil replenishment channels (340), one of which connects to the pump chamber (330) and the other of which connects to the side chamber (332).

6. An electro-hydraulic actuator according to claim 1, characterized in that, The valve seat (400) is equipped with a manual relief valve (470) and a relief check valve (480). The manual relief valve (470) and the relief check valve (480) can relieve pressure on the hydraulic cylinder (100). The manual relief valve (470) includes a control lever (471), a pressure relief lever (472), and a manual relief spring (473); the pressure relief lever (472) is mounted on the bottom of the control lever (471), and the manual relief spring (473) is used to help the control lever (471) reset; a limit pin (474) is mounted on the control lever (471), and a switching groove (202) that cooperates with the limit pin (474) is provided on the housing of the oil reservoir (200); the groove depth at one end of the switching groove (202) is greater than the groove depth at the other end, and the groove depths at both ends correspond to the closed state and the open state of the manual relief valve (470) respectively; The valve seat (400) is provided with a manual relief groove (380) that connects to the receiving cavity (201), and the pressure relief rod (472) is located in the manual relief groove (380); the hydraulic cylinder (100) is provided with a relief control groove (106) corresponding to the manual relief groove (380), and the pressure relief check valve is located in the relief control groove (106); when the manual relief valve (470) is opened, the pressure relief rod (472) descends and opens the relief check valve (480), and the oil in the cavity of the hydraulic cylinder (100) enters the receiving cavity (201) through the manual relief groove (380).

7. An electro-hydraulic actuator according to claim 1, characterized in that, The valve seat (400) is also equipped with an automatic relief valve, which includes a rodless relief valve (460) and a rod relief valve (461); the valve seat (400) is provided with a relief passage for assembling the automatic relief valve, and the relief passage is divided into a rodless relief passage (370) connecting the rodless chamber (101) and a rod relief passage (371) connecting the rod chamber (102) corresponding to the rodless relief valve (460) and the rod relief valve (461). The automatic relief valve includes a push rod (462) and an automatic relief spring (463). A spherical plug is provided at the bottom of the push rod (462). One end of the automatic relief spring (463) abuts against the inner wall of the receiving cavity (201), and the other end abuts against the push rod (462). Under the action of the automatic relief spring (463), the spherical plug blocks the relief channel. When the oil pressure in the rod chamber (102) or the rodless chamber (101) exceeds a certain value, the oil pressure will push the push rod (462) upward, and the oil will flow through the relief channel into the receiving cavity (201).

8. An electro-hydraulic actuator according to claim 1, characterized in that, The valve seat (400) is also provided with a pressure relief channel (360), which is connected to the extended assembly cavity (311) and the retracted assembly cavity (321). The pressure relief channel (360) is equipped with a channel pressure relief valve (450), which can relieve pressure on the channel structure (300) by manually opening the channel pressure relief valve (450).

9. An electro-hydraulic actuator according to claim 1, characterized in that, The cavity of the hydraulic cylinder (100) is equipped with a through pipe (130), and the piston (110) is installed inside the through pipe (130). There is a space between the through pipe (130) and the inner wall of the cavity. A partition ring (140) is installed on the outer wall of the through pipe (130). The partition ring (140) divides the space into a rodless connection space (103) that connects to the rodless cavity (101) and a rod connection space (104) that connects to the rod cavity (102). The extended flow channel (310) connects to the rodless connection space (103), and the retracted flow channel (320) connects to the rod connection space (104).

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