High-frequency heavy-load oil cylinder and double-loop hydraulic servo driving system

Abstract

The invention discloses a high-frequency heavy-load oil-resistant cylinder and double-loop hydraulic servo driving system. Relates to the technical field of hydraulics. Hydraulic centering supporting structures are designed in the front end cover and the rear end cover, a plurality of evenly-distributed grooves and oil inlet supporting holes are formed in the inner side wall of the shaft hole, high-pressure oil enters the grooves through the oil inlet supporting holes, an even hydraulic supporting oil film is formed on the periphery of the piston rod, the piston rod is in a dynamic centering state all the time, and the service life of the piston rod is prolonged. The problems of single-side contact, eccentric wear and clamping stagnation caused by the dead weight of a piston rod of a traditional heavy-load oil cylinder are fundamentally solved. The hydraulic supporting oil film can greatly reduce frictional resistance and abrasion loss, reduce damage to sealing pieces, reduce leakage risks and remarkably prolong the service life of the oil cylinder. Meanwhile, the oil film has buffering and vibration absorption effects, impact and pulsation in high-frequency operation can be effectively absorbed, and the operation stability of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic technology, and more particularly to a high-frequency heavy-duty anti-oil cylinder and a dual-circuit hydraulic servo drive system. Background Technology

[0002] In high-frequency, heavy-duty industrial applications, hydraulic cylinders, as core actuators, directly determine the reliability and production efficiency of the entire system through their operational stability and service life. Currently, traditional heavy-duty hydraulic cylinders generally face multiple technical bottlenecks in actual working conditions: Firstly, the piston rod has a large self-weight under heavy load conditions. Especially when it is installed in a horizontal layout, and when the piston rod of the cylinder is subjected to a horizontal lateral force, the high-frequency reciprocating motion is very likely to cause the piston rod to have one-sided contact friction with the shaft hole of the front and rear end caps. This not only accelerates the wear of the seals and the inner wall of the shaft hole, but also easily causes leakage, jamming and other faults, which seriously restricts the service life of the cylinder. Secondly, existing hydraulic cylinders lack an effective dynamic centering support structure. Under high-frequency impact loads, the piston rod is prone to radial displacement, which exacerbates local stress concentration and leads to a significant decrease in fatigue life, making it difficult to meet the application requirements of high reliability and long service life.

[0003] Furthermore, while some existing hydraulic cylinders employ mechanical supports or guide sleeve structures to alleviate uneven wear, their support effectiveness is limited under high-frequency, heavy-load conditions, and they are prone to decreased support accuracy due to wear, failing to fundamentally solve the piston rod centering problem. Addressing these industry pain points, how to achieve dynamic piston rod centering and effectively avoid unilateral contact friction is a crucial technical issue that needs to be resolved in this case.

[0004] Third, if the friction is too high during high-frequency operation, it is easy to generate heat. Therefore, the friction must be reduced to control the heat generation.

[0005] In summary, existing heavy-duty hydraulic cylinders suffer from a combination of problems such as piston rod wear, radial offset, and frictional heat generation under high-frequency heavy-duty conditions, which seriously affect their operational stability, sealing reliability, and overall service life. Therefore, developing a heavy-duty hydraulic cylinder that can achieve dynamic centering of the piston rod, effectively reduce frictional losses, and control heat generation has become a technical challenge that urgently needs to be overcome in this field. Summary of the Invention

[0006] To address the above problems, this invention provides a high-frequency heavy-load anti-oil cylinder and dual-circuit control hydraulic drive system that achieves dynamic centering of the piston rod under high-frequency heavy-load conditions, effectively avoids unilateral contact friction, and improves system stability and reliability.

[0007] The technical solution of this invention is: A high-frequency heavy-duty hydraulic cylinder includes: The hydraulic cylinder has a fixedly connected support sleeve at its tail end; the two ends of the hydraulic cylinder piston rod extend out of the hydraulic cylinder respectively, and the piston rod end at the tail end is located inside the support sleeve. A pressure sensor is fixedly connected to the front end of the piston rod of the hydraulic cylinder; The front connector is fixedly connected to the pressure sensor; The rear connector is fixedly connected to the support sleeve; The displacement sensor has its stationary end fixedly clamped in the rear connector, and its moving rod end fixed inside the front end of the cylinder piston rod. The front end cover and / or rear end cover of the hydraulic cylinder are respectively provided with shaft holes; the inner sidewall of the shaft hole is provided with multiple evenly distributed grooves, and oil is introduced through the oil inlet support holes in the multiple grooves to achieve the centering of the piston rod in the shaft hole.

[0008] Specifically, the sealing and sliding fit between the piston of the hydraulic cylinder and the inner wall of the cylinder body includes one of the following two methods: The sliding connection is sealed by the first sealing element; A gap seal is formed by plating a hard chrome layer on the outer surface of the piston and / or the inner wall surface of the cylinder.

[0009] Specifically, the front cylinder head of the hydraulic cylinder is provided with an oil drain hole; the oil drain hole is connected to a vacuum generator; The vacuum generator is provided with an air inlet, a throttling channel and an air outlet connected in sequence; the flow cross-sectional area of ​​the throttling channel is smaller than the flow cross-sectional area of ​​the air inlet and the air outlet, respectively. The inner end of the air outlet is connected to the vacuum hole and the oil discharge hole of the vacuum valve block, respectively, and the outer end is connected to the oil tank; the vacuum negative pressure generated by the vacuum generator draws the oil in the oil discharge hole to the air outlet, and mixes with the airflow before blowing it into the oil tank.

[0010] Specifically, the stationary end of the displacement sensor is fixedly clamped in the rear connector, and the moving rod end is fixedly disposed inside the front end of the cylinder piston rod.

[0011] Specifically, the hydraulic cylinder includes a cylinder liner, a front end cover, a rear end cover, a piston rod, and a support sleeve; The piston rod is slidably disposed within the cylinder liner; The support sleeve is fixedly mounted on the rear end cover.

[0012] Specifically, the front end cover and / or rear end cover are provided with a hydraulic support oil inlet pipe on one side and a hydraulic support oil drain pipe on the other side; The inlet ends of the multiple oil inlet support holes are respectively connected to the oil inlet pipe of the hydraulic support, and the outlet ends are respectively connected to the oil drain pipe of the hydraulic support.

[0013] Specifically, the front connector and / or rear connector are hinged joints.

[0014] A dual-circuit controlled hydraulic servo drive system includes a servo valve; The P port of the pair of servo valves is connected to the oil source, the T port of the return oil is connected to the oil tank, the A port of the oil valve is connected to the first chamber of the oil cylinder, and the B port of the oil valve is connected to the second chamber of the oil cylinder.

[0015] Specifically, the P port of the servo valve is connected to the first accumulator.

[0016] Specifically, the return oil T-port is connected to the second accumulator.

[0017] This invention incorporates a hydraulic centering support structure in the front and rear covers. Multiple evenly distributed grooves and oil inlet support holes are provided on the inner wall of the shaft hole. High-pressure oil enters the grooves through the oil inlet support holes, forming a uniform hydraulic support oil film on the outer circumference of the piston rod. This ensures the piston rod remains dynamically centered, fundamentally solving the problems of one-sided contact, uneven wear, and jamming caused by the piston rod's own weight in traditional heavy-duty cylinders. The hydraulic support oil film significantly reduces frictional resistance and wear, minimizes seal damage, lowers leakage risk, and significantly extends cylinder lifespan. Simultaneously, the oil film provides buffering and vibration absorption, effectively absorbing impacts and pulsations during high-frequency operation, improving system stability. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 , Figure 2 yes Figure 1 Schematic diagram of the I-direction structure; Figure 3 This is a schematic diagram of the connection state structure of the vacuum generator; Figure 4 yes Figure 3 Schematic diagram of the A-direction structure; Figure 5 This is a schematic diagram of the hydraulic cylinder structure; Figure 6 yes Figure 5 A schematic diagram of the B-axis structure, with the arrows indicating the direction of hydraulic oil flow. Figure 7 yes Figure 5 A schematic diagram of the C-axis structure, with the arrows indicating the direction of hydraulic oil flow. Figure 8 This is a schematic diagram of the three-dimensional structure of the front cover; Figure 9 This is a hydraulic schematic diagram of a dual-circuit controlled hydraulic servo drive system; In the diagram, 100 represents the hydraulic cylinder, 101 is the shaft hole, 102 is the groove, 103 is the oil inlet support hole, 120 is the hydraulic support oil inlet pipe, and 130 is the hydraulic support oil drain pipe. 110 is the support sleeve. 200 is a pressure sensor. 300 is the front connector. 400 is the rear connector. 500 is a displacement sensor. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having 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.

[0020] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The following is for reference. Figure 1-9 Description based on embodiments of the invention; A high-frequency heavy-duty hydraulic cylinder, such as Figure 1-2 As shown, it includes: The hydraulic cylinder 100 has a fixedly connected support sleeve 110 at its tail end; the piston rod of the hydraulic cylinder 100 extends out of the hydraulic cylinder 100 at both ends, and the piston rod end at the tail end is located inside the support sleeve 110. The pressure sensor 200 is fixedly connected to the front end of the piston rod of the hydraulic cylinder 100 via a rear connecting screw; The front connector 300 is fixedly connected to the pressure sensor 300 via a front connecting screw; the gap generated when the front and rear connecting screws are connected can be eliminated by a spiral loosening washer; The rear connector 400 is fixedly connected to the support sleeve 110; The displacement sensor 500 has its stationary end fixedly clamped in the rear connector 400, and its moving rod end fixed inside the front end of the piston rod of the hydraulic cylinder 100. The front end cover and / or rear end cover of the hydraulic cylinder 100 are respectively provided with shaft holes 101; the inner sidewall of the shaft hole is provided with a plurality of evenly distributed grooves 102, and oil is introduced through the oil inlet support holes 103 in the plurality of grooves 102 to achieve the centering of the piston rod in the shaft hole 101.

[0023] For heavy-duty hydraulic cylinders, the piston rod is relatively heavy. To prevent horizontal placement and the influence of lateral forces, and to avoid one-sided contact friction between the piston rod and the front and rear covers during high-frequency operation, the front and rear covers are designed with a hydraulically supported structure to reduce wear and improve the service life and stability of the hydraulic cylinder.

[0024] This invention adopts a double-outlet piston rod structure and a support sleeve 110 is provided at the tail of the cylinder, which can provide reliable guidance and radial support for the tail of the piston rod, effectively reducing the downward displacement of the piston rod due to its own weight during horizontal arrangement and high-frequency reciprocating motion, avoiding local overload and stress concentration, and improving the overall structural rigidity and impact resistance.

[0025] The integrated design of the pressure and displacement sensors enables real-time and accurate detection of the cylinder's output load and displacement signals, providing data support for closed-loop control and ensuring precise action response and stable, reliable operation. The displacement sensor is built into the piston rod, occupying no external space and unaffected by external environmental interference or impact damage, significantly improving the sensor's operational stability and lifespan. The front and rear connectors are rigidly connected via connecting screws, and spiral anti-loosening washers eliminate connection gaps, preventing loosening, abnormal noise, and monitoring errors under long-term high-frequency vibration, significantly enhancing the reliability and durability of the connection structure.

[0026] The stationary end of the displacement sensor 500 is sealed and fixedly clamped in the rear connector 400, and the moving rod end is sealed and fixedly disposed inside the front end of the piston rod of the hydraulic cylinder 100.

[0027] The sealing and sliding fit between the piston of hydraulic cylinder 100 and the inner wall of the cylinder body includes: A gap seal is formed by plating a hard chrome layer on the outer surface of the piston and / or the inner wall surface of the cylinder. The piston of the hydraulic cylinder 100 is slidably connected to the inner wall of the cylinder body through a first seal. The first seal is a double-acting, heavy-duty, wear-resistant Tecomogley ring that can withstand high pressure of 50MPa, speed of 15mm / s, frequency of 5HZ, and temperature of -45°C to 200°C.

[0028] The hydraulic cylinder 100 includes a cylinder liner, a front end cover, a rear end cover, a piston rod, and a support sleeve 110; The piston is slidably disposed within the cylinder liner; The front end cover is detachably disposed at one end of the cylinder liner, and the rear end cover is detachably disposed at the other end of the cylinder liner; The support sleeve 110 is fixedly mounted on the rear end cover.

[0029] To meet the high-speed requirements of the hydraulic cylinder, a sealing ring is installed on the piston. This sealing ring is a double-acting, heavy-duty Tequilaite ring, resistant to pressures of 50MPa, speeds of 15m / s, frequencies up to 5Hz, and temperatures of -45 to 200 degrees Celsius. To reduce friction between the piston rod / piston section and the cylinder liner, the outer circumference of the piston section is plated with a high-polymer wear-resistant material. The outer circumferences of the piston rod and the front and rear end caps are plated with wear-resistant hard chrome. The front and rear end caps are fastened to both ends of the cylinder liner with screws.

[0030] A hydraulic support oil inlet pipe 120 is provided on one side of the front cover and / or the rear cover, and a hydraulic support oil drain pipe 130 is provided on the other side; The inlet ends of the plurality of oil inlet support holes 103 are respectively connected to the hydraulic support oil inlet pipe 120, and the outlet ends are respectively connected to the hydraulic support oil drain pipe 130.

[0031] Hydraulic fluid in the hydraulic support inlet pipe 120 flows into multiple grooves 102 through a throttle valve. The combined action of the fluid at multiple angles dynamically lifts the piston rod to the center of the front and rear end covers. Assuming the piston rod is laterally positioned and sinks, meaning the gap below the piston rod decreases, the hydraulic pressure at that point is high, pushing the piston rod upwards. Once it moves past the center, the upper gap decreases, increasing the hydraulic pressure, while the lower gap increases, decreasing the hydraulic pressure. This pressure difference causes the piston rod to move downwards, thus keeping it centered between the front and rear end covers during dynamic operation. The surfaces of the front and rear end covers that contact the piston rod are coated with a wear-resistant polymer layer, resulting in low frictional resistance and a long service life. The pressurized oil in the grooves flows through the gap between the piston rod and the front and rear end covers into the hydraulic support drain pipe 130, where it is discharged.

[0032] The front connector 300 and / or the rear connector 400 are hinge joints. The front connector 300 is connected to the test specimen, and the rear connector 400 is generally a fixed support connection; the hinge joints can be selected using readily available parts in the prior art for compatibility.

[0033] The front cylinder head of the hydraulic cylinder 100 and the piston rod are connected in a sealed sliding connection by a second seal.

[0034] In practical applications of high-frequency heavy-duty hydraulic cylinders, the sealing performance of the cylinder head and piston rod directly affects the cylinder's operational stability, service life, and environmental friendliness. The rationality of the sealing structure is one of the key factors restricting the adaptability of heavy-duty hydraulic cylinders to high-frequency heavy-duty operating conditions. Currently, the industry commonly uses traditional sealing rings to achieve sealing between the cylinder head and piston rod. The elastic preload of the sealing ring fills the gap, thus preventing oil leakage.

[0035] However, under heavy-load conditions of high-frequency reciprocating motion, high-pressure impact, and temperature fluctuation, traditional sealing ring methods have many insurmountable technical defects: Firstly, there is continuous sliding friction between the sealing ring and the piston rod. The high-frequency reciprocating motion easily leads to wear, aging, and tearing of the sealing ring and lip. At the same time, the heat generated by friction will further accelerate the failure of the seal. Not only does it require regular disassembly of the cylinder head to replace the seal, increasing maintenance costs and downtime, but it is also easy for oil leakage to occur due to seal failure, causing environmental pollution and hydraulic oil waste. Secondly, the sealing ring seal is a passive sealing type, which relies on the precise fit between the sealing element and the mating surface. When the piston rod wears unevenly due to radial offset, the sealing gap will change irregularly, the sealing reliability will drop significantly, and failures such as leakage and jamming will easily occur, further aggravating the wear of the piston rod and cylinder head shaft hole. Third, under high pressure conditions, the sealing ring is easily squeezed into the mating gap, which can lead to damage to the sealing components and jamming of the piston movement. At the same time, the pre-tightening force of the sealing components will increase the friction of the piston rod movement, increase the energy consumption of the hydraulic cylinder, and the frictional heat will further affect the overall operational stability of the hydraulic cylinder. Fourth, traditional sealing rings cannot recycle leaked oil. Once the seal fails, the oil leaks directly, which not only pollutes the working environment but also causes insufficient lubrication of the hydraulic system and aggravates the wear of internal components.

[0036] Furthermore, while some improved sealing structures in existing technologies attempt to alleviate the aforementioned problems, they all remain fundamentally based on the core logic of "passive sealing," failing to address the inherent defects of seal wear, leakage, and frictional heat generation. This makes them unsuitable for the high reliability, long lifespan, low maintenance, and environmentally friendly application requirements of high-frequency, heavy-duty hydraulic cylinders. Therefore, a completely new sealing solution is urgently needed to replace traditional sealing rings, fundamentally solving the industry pain points of oil leakage, excessive frictional loss, and high maintenance costs, and meeting the practical application needs of high-frequency, heavy-duty hydraulic cylinders. To address the above issues, the technical solutions adopted for the front cover and / or rear cover in this case are as follows: Figure 3-4 : The front cylinder cover of the hydraulic cylinder 100 is provided with an oil discharge hole; the oil discharge hole is connected to a vacuum generator; The vacuum generator is provided with an air inlet, a throttling channel and an air outlet connected in sequence; the flow cross-sectional area of ​​the throttling channel is smaller than the flow cross-sectional area of ​​the air inlet and the air outlet, respectively. The inner end of the air outlet is connected to the vacuum hole and the oil discharge hole of the vacuum valve block, respectively, and the outer end is connected to the oil tank; the vacuum negative pressure generated by the vacuum generator draws the oil in the oil discharge hole to the air outlet, and mixes with the airflow before blowing it into the oil tank.

[0037] In summary, this technology replaces traditional sealing rings with vacuum suction. Through the coordinated operation of the vacuum valve block, vacuum generator, and cylinder head oil drain hole, it achieves active oil suction and recovery, eliminating vulnerable sealing components such as traditional sealing rings. This fundamentally avoids problems such as wear, tearing, and failure caused by high-frequency friction, high-pressure extrusion, and temperature aging of sealing rings, significantly reducing the failure rate of the hydraulic cylinder. It also avoids maintenance costs and downtime losses associated with seal replacement, significantly extending the service life of the cylinder head, piston rod, and the entire system, and is suitable for long-term operation under high-frequency and heavy loads. Traditional sealing rings provide passive sealing, which is prone to oil leakage due to seal failure. Vacuum suction, on the other hand, generates a stable negative pressure through a vacuum generator, actively sucking leaked oil from the cylinder head to the exhaust port. After mixing with the airflow, the oil is blown into the oil tank for closed-loop recovery. This not only completely eliminates environmental pollution caused by oil leakage but also achieves 100% recycling of hydraulic oil, avoiding resource waste and reducing hydraulic oil replenishment costs, thus meeting environmental protection and energy-saving requirements.

[0038] Meanwhile, the sealless design eliminates the sliding friction between the traditional sealing ring and the piston rod, significantly reducing the frictional force of the piston rod movement, reducing frictional heat generation, and effectively controlling the temperature rise during cylinder operation. This avoids problems such as changes in hydraulic oil viscosity and accelerated aging of seals caused by heat generation. Simultaneously, the absence of friction interference makes the piston rod movement smoother, eliminating jamming and low-speed crawling, improving the cylinder's operational stability and response speed, and reducing system energy consumption. Under high-frequency, heavy-load conditions, the piston rod is prone to radial displacement. Traditional sealing rings may fail due to changes in clearance. However, vacuum suction actively draws in leaked oil through negative pressure. Even with slight radial displacement of the piston rod and changes in the fit clearance, stable oil suction and recovery can be achieved without relying on precise sealing. This adapts to complex conditions of piston rod wear and fundamentally solves the problem of insufficient reliability of traditional sealing methods.

[0039] The hydraulic cylinder requires high frequency, i.e., high speed, so V should be a large value. It also needs to withstand heavy loads. Therefore, with a fixed system pressure of 21 MPa, the cylinder area needs to be large, so A should also be a large value. These two factors necessitate a large flow rate Q = VA, meaning a large flow rate is required into the cylinder. In hydraulic systems, to achieve high frequency and heavy loads, the required flow rate of the servo valve is relatively large. Electro-hydraulic servo valves are generally imported, but high-flow-rate imported electro-hydraulic servo valves are expensive and have long delivery times. To solve this problem, we designed a high-flow-rate hydraulic system.

[0040] A dual-circuit controlled hydraulic drive system includes a pair of small servo valves; The P port of the pair of servo valves ( Figure 7 P1 and P2 are connected to the oil source respectively, and the return oil T port ( Figure 7 T1 and T2 are connected to the oil tank respectively, and oil port A ( Figure 7 A1 and A2 are respectively connected to the first cavity of the oil cylinder ( Figure 7 Connect the left-side cavity to the oil port B. Figure 7 B1 and B2 are respectively connected to the second cavity of the oil cylinder ( Figure 7 (Connected to the right side cavity).

[0041] The P port of the servo valve in this case is connected to the first accumulator. The T port for oil return is connected to the second accumulator.

[0042] This hydraulic system employs a dual-path high-pressure oil supply architecture, with high-pressure oil entering the corresponding servo valves through two independent ports, P1 and P2. At the electrical control level, the servo valves utilize a synchronous drive strategy to achieve coordinated valve core movement. For example... Figure 7 As shown, taking the leftward movement of the valve core as an example, high-pressure oil is simultaneously output through ports A1 and A2, and after merging, enters the left chamber of the hydraulic cylinder, jointly pushing the piston to the right. The return oil from the right chamber of the hydraulic cylinder flows through ports B1 and B2 into the T1 and T2 return oil channels, eventually flowing back to the oil tank. This design, by employing two conventional low-flow servo valves operating in parallel, doubles the effective flow rate provided to the hydraulic cylinder compared to a single-valve solution, thereby simultaneously increasing the operating frequency of the hydraulic cylinder to twice the original level, significantly improving the dynamic response capability of the actuator. Furthermore, accumulators are installed at the inlet and outlet of each directional valve, effectively absorbing hydraulic shocks and suppressing pressure pulsations, ensuring smooth oil flow, and improving the stability and reliability of the system operation.

[0043] The operational process in this case included: 1. Connect the interference-fit front spherical connector to the test sample, and connect the interference-fit rear spherical connector to the fixed support. Then, use spiral washers to eliminate the gap between the front spherical connector and the front connecting screw of the pressure sensor, and eliminate the gap between the pressure sensor and the rear connecting screw of the hydraulic cylinder piston rod.

[0044] 2. Hydraulic support for oil inlet; the cylinder piston rod is positioned at the center of the cylinder under high-frequency, heavy-load, fatigue-resistant conditions during dynamic operation, such as... Figure 4 As shown, hydraulic support drain oil flows out from the hydraulic support drain pipe.

[0045] Two conventional low-flow servo valves operate simultaneously, and pressurized oil enters the piston rod rightward port of the oil cylinder. The rightward stroke is output by the displacement sensor, and the force of the oil cylinder pulling the test sample is output by the pressure sensor.

[0046] Two conventional low-flow servo valves switch direction simultaneously, the hydraulic cylinder switches direction, the displacement sensor outputs in reverse, and the pressure sensor outputs the force that pushes the sample.

[0047] The hydraulic cylinder assembly in this case has the following significant advantages: it can fully adapt to the heavy-load and high-frequency operation requirements of the test sample, and significantly improve the fatigue life and operational stability of the assembly: 1. The piston part of the hydraulic cylinder piston rod is equipped with wear-resistant seals suitable for high-frequency and heavy-load conditions. At the same time, the part is coated with high-polymer wear-resistant material, which not only further improves the wear resistance and fatigue life of the piston part, but also effectively reduces the frictional resistance between the piston and the cylinder liner, ensuring the smooth reciprocating motion of the piston.

[0048] 2. The piston rod of the hydraulic cylinder adopts a hydraulic support structure, which can dynamically support the piston rod at the center position of the hydraulic cylinder. At the same time, a stable oil film is formed on the outer periphery of the piston rod, which fundamentally eliminates the one-sided friction between the piston rod and the front and rear cylinder heads caused by its own weight under heavy load conditions. It can also automatically adjust the influence of lateral force on the position of the piston rod, avoiding local wear and stress concentration.

[0049] 3. The piston rod of the hydraulic cylinder is plated with wear-resistant hard chrome at both ends, which significantly improves the overall wear resistance of the piston rod; the inner surfaces of the front cylinder head and the rear cylinder head that are in contact with the piston rod are plated with high-polymer wear-resistant materials, which further optimizes the wear resistance of the contact parts, reduces the frictional resistance between the piston rod and the cylinder head, effectively extends the fatigue life of each contact part, and improves the overall durability of the components.

[0050] 4. The dual servo valve synchronous working mode is adopted, which increases the operating frequency of the hydraulic cylinder to twice that of the traditional single valve control, greatly improving the working efficiency; accumulators are installed at both the oil inlet and outlet of the servo valve to provide a stable power oil source, effectively absorb hydraulic shock, suppress pressure pulsation, and ensure that the hydraulic cylinder can achieve stable high-frequency operation and reversing action, avoiding operation disorder under high-frequency conditions.

[0051] 5. The spherical connectors that connect to the test sample and the spherical connectors that connect to the fixed support are all designed with an interference fit, which can effectively resist vibration interference caused by heavy load and high frequency operation, ensure the displacement output accuracy of the displacement sensor and the pressure output accuracy of the pressure sensor, and ensure the accuracy of the test data.

[0052] 6. The spiral gasket structure effectively eliminates the gap at the connection point with the pressure sensor, avoiding loosening of the connection caused by long-term heavy load and high-frequency vibration, further ensuring the output accuracy of the displacement sensor and pressure sensor, and ensuring the monitoring reliability during component operation.

[0053] 7. Vacuum extraction in oil production replaces sealing, greatly reducing friction.

[0054] In summary, this hydraulic cylinder assembly, through multi-dimensional structural optimization and material improvement, achieves an organic combination of wear resistance, fatigue resistance, high precision, and high stability. It is a hydraulic cylinder assembly that is suitable for heavy-load and high-frequency operating conditions of test samples, and has a long fatigue life and reliable operation.

[0055] Regarding the information disclosed in this case, the following points need to be clarified: (1) The accompanying drawings of the embodiments disclosed in this case only involve the structures involved in the embodiments disclosed in this case. Other structures can refer to the general design. (2) Where there is no conflict, the embodiments and features disclosed in this case can be combined with each other to obtain new embodiments; The above are merely specific embodiments disclosed in this case, but the scope of protection of this disclosure is not limited thereto. The scope of protection disclosed in this case shall be determined by the scope of protection of the claims.

Claims

1. A high-frequency heavy-duty hydraulic cylinder, characterized in that, include: The hydraulic cylinder (100) has a fixedly connected support sleeve (110) at its tail end; the piston rod of the hydraulic cylinder (100) extends out of the hydraulic cylinder (100) at both ends, and the piston rod end at the tail end is located inside the support sleeve (110); A pressure sensor (200) is fixedly connected to the front end of the piston rod of the hydraulic cylinder (100); The front connector (300) is fixedly connected to the pressure sensor (300); The rear connector (400) is fixedly connected to the support sleeve (110); The displacement sensor (500) has its stationary end fixedly clamped in the rear connector (400), and its moving rod end fixed inside the front end of the piston rod of the hydraulic cylinder (100). The front end cover and / or rear end cover of the cylinder (100) are respectively provided with shaft holes (101); the inner sidewall of the shaft hole is provided with a plurality of evenly distributed grooves (102), and oil is introduced through the oil inlet support holes (103) in the plurality of grooves (102) to realize the piston rod in the shaft hole (101) being centered; The front cylinder cover of the oil cylinder (100) is provided with an oil discharge hole; the oil discharge hole is connected to a vacuum generator; The vacuum generator is provided with an air inlet, a throttling channel and an air outlet connected in sequence; the flow cross-sectional area of ​​the throttling channel is smaller than the flow cross-sectional area of ​​the air inlet and the air outlet, respectively. The inner end of the air outlet is connected to the vacuum hole and the oil discharge hole of the vacuum valve block, respectively, and the outer end is connected to the oil tank; the vacuum negative pressure generated by the vacuum generator draws the oil in the oil discharge hole to the air outlet, and mixes with the airflow before blowing it into the oil tank.

2. The high-frequency heavy-duty hydraulic cylinder according to claim 1, characterized in that, The piston of the oil cylinder (100) is slidably connected to the inner wall of the cylinder body by a first seal.

3. Another high-frequency heavy-duty hydraulic cylinder according to claim 1, characterized in that, The piston of the oil cylinder (100) is sealed to the inner wall of the cylinder by coating the outer surface of the piston with a high-molecular wear-resistant material to form a gap seal with the cylinder.

4. A high-frequency heavy-duty hydraulic cylinder according to claim 1, characterized in that, The stationary end of the displacement sensor (500) is fixedly clamped in the rear connector (400), and the moving rod end is fixedly disposed inside the front end of the piston rod of the oil cylinder (100).

5. A high-frequency heavy-duty hydraulic cylinder according to claim 1, characterized in that, The hydraulic cylinder (100) includes a cylinder liner, a front end cover, a rear end cover, a piston rod, and a support sleeve (110). The piston rod is slidably disposed within the cylinder liner; The front end cover is detachably disposed at one end of the cylinder liner, and the rear end cover is detachably disposed at the other end of the cylinder liner; The support sleeve (110) is fixedly mounted on the rear end cover.

6. A high-frequency heavy-duty hydraulic cylinder according to claim 1, characterized in that, The front end cover and / or rear end cover are provided with a hydraulic support oil inlet pipe (120) on one side and a hydraulic support oil drain pipe (130) on the other side. The inlet ends of the plurality of oil inlet support holes (103) are respectively connected to the hydraulic support oil inlet pipe (120), and the outlet ends are respectively connected to the hydraulic support oil drain pipe (130).

7. A high-frequency heavy-duty hydraulic cylinder according to claim 1, characterized in that, The front connector (300) and / or the rear connector (400) are hinged joints.

8. A dual-circuit controlled hydraulic servo drive system, applied to a high-frequency heavy-duty hydraulic cylinder as described in claim 1, characterized in that, Includes a pair of servo valves; The P port of the pair of servo valves is connected to the oil source, the T port of the return oil is connected to the oil tank, the A port of the oil valve is connected to the first chamber of the oil cylinder, and the B port of the oil valve is connected to the second chamber of the oil cylinder.

9. A dual-loop controlled hydraulic servo drive system according to claim 8, characterized in that, The P port of the servo valve is connected to the first accumulator.

10. A dual-loop controlled hydraulic servo drive system according to claim 8, characterized in that, The return oil T-port is connected to the second accumulator.

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