A test test bench based on hydraulic lifting oil cylinder

Abstract

The application discloses a kind of test test bench based on hydraulic lifting oil cylinder, it is related to oil cylinder detection technical field, including rack, measured oil cylinder and drive mechanism are arranged in rack, the output end of drive mechanism is connected with the output shaft of measured oil cylinder, multiple support columns are arranged in parallel in rack, deflection compensation mechanism and swing loading mechanism are arranged in rack;Deflection compensation mechanism is used to offset the radial deflection generated by piston rod deadweight in real time;Swing loading mechanism is used to realize the complete decoupling loading of axial main load and radial dynamic load, and simulate dynamic swing radial load in actual hoisting working condition.The application is set by deflection compensation mechanism, by servo mechanism first sliding seat is driven with measured oil cylinder output shaft synchronous servo, so that support bearing bush is always in the midpoint position of output shaft extension section, rigid static pressure oil film is formed by the aid of sector static pressure oil cavity in support bearing bush, and the radial deflection generated by piston rod deadweight is offset by adaptive adjustment oil cavity pressure.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder testing technology, and in particular to a test bench based on a hydraulic lifting cylinder. Background Technology

[0002] Hydraulic lifting cylinders, as core actuators for heavy-duty lifting operations, are widely used in major engineering projects such as bridge synchronous lifting, large steel structure hoisting, heavy-duty mining lifting, and tunnel boring machine propulsion. In these applications, hydraulic lifting cylinders are typically installed vertically. To ensure the service safety and performance stability of hydraulic lifting cylinders, precise testing of their full-condition performance is required using a dedicated testing bench to accurately reproduce the stress state of the cylinder during actual service and obtain reliable performance parameters. However, existing testing devices for long-stroke vertically installed hydraulic lifting cylinders still have the following shortcomings during use: When the piston rod of the lifting cylinder is fully extended, it will experience significant radial deflection due to its own weight. During operation, the cylinder will also be subjected to dynamic oscillating radial loads and eccentric bending moments with real-time changes in direction and amplitude due to factors such as wind force on the lifted structure, positioning deviation, and multi-cylinder synchronization errors. However, existing lifting cylinder testing devices cannot reproduce the complex working conditions of the tested cylinder during actual service, specifically in the following ways: Firstly, for large-tonnage hydraulic cylinders with long strokes and vertical installation, the coaxiality error caused by the deflection of the piston rod at the end of the long stroke will generate additional bending moment, which seriously interferes with the testing accuracy of core performance parameters such as internal leakage, starting pressure, and friction coefficient of the cylinder, and cannot guarantee the authenticity of the test data. Secondly, when applying radial load to simulate actual hoisting conditions, the application of radial force will directly cause drastic fluctuations in axial loading force due to the dynamic swinging radial load with randomly changing direction and amplitude in the hoisting conditions. This cannot guarantee the stability of the test conditions and thus affects the accuracy of the test. Summary of the Invention

[0003] The purpose of this application is to provide a test bench based on a hydraulic lifting cylinder, which can effectively solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this application provides the following technical solution: a test bench based on a hydraulic lifting cylinder, comprising a frame, wherein a test cylinder and a drive mechanism are disposed within the frame, the output end of the drive mechanism is connected to the output shaft of the test cylinder, a plurality of support columns are arranged parallel to each other within the frame, and a deflection compensation mechanism and a swing loading mechanism are disposed within the frame; the deflection compensation mechanism is used to offset the radial deflection generated by the self-weight of the piston rod in real time, so as to achieve dynamic adaptive compensation throughout the stroke; the swing loading mechanism is used to achieve complete decoupling of the axial main load and the radial dynamic load, and to simulate the dynamic swing radial load in actual hoisting conditions; the deflection compensation mechanism includes: a first sliding seat, a support bearing, a follow-up mechanism, and a load compensation mechanism; wherein, the first sliding seat is slidably connected to the support column along the axis of the support column; the first A through hole is provided on the sliding seat, and the output shaft of the tested cylinder is coaxially inserted into the through hole; the support bearing is coaxially sleeved between the output shaft of the tested cylinder and the through hole; a gap is reserved between the inner hole of the support bearing and the outer circular surface of the output shaft of the tested cylinder; four sets of fan-shaped hydrostatic oil chambers are provided on the inner circumference of the support bearing, and each set of fan-shaped hydrostatic oil chambers is provided with an independent throttling orifice, which is connected to an external constant pressure hydraulic oil source through a high-pressure hose; the follower mechanism is provided between the output end of the drive mechanism and the first sliding seat; when the drive mechanism drives the output shaft of the tested cylinder to extend or retract, the first sliding seat is allowed to follow through the follower mechanism, and the stroke of the first sliding seat is half of the extension or retraction stroke of the output shaft of the tested cylinder; the load compensation mechanism is provided between the frame and the first sliding seat, and is used to offset the additional load generated when the drive mechanism drives the first sliding seat to move.

[0005] Preferably, the support column is provided with a slide rail, and the length direction of the slide rail is parallel to the axis of the support column. A slider is slidably connected to the slide rail, and the slider is fixed to the first sliding seat.

[0006] Preferably, the supporting bearing includes an upper sealing section, a working surface support section, and a lower sealing section; the supporting bearing is a coaxial, integrated three-section annular sleeve structure; the upper sealing section, the working surface support section, and the lower sealing section are coaxially connected in sequence, and the inner diameters of the upper sealing section, the working surface support section, and the lower sealing section are completely identical, with no step difference; both the upper and lower sealing sections have mounting grooves; a sealing ring is provided in the mounting groove, which is used to achieve static sealing between the outer circle of the supporting bearing and the through hole of the first sliding seat, so as to prevent high-pressure oil from leaking from the mating surface.

[0007] Preferably, the fan-shaped hydrostatic oil chamber is located on the inner circular surface of the working face support section, and each fan-shaped hydrostatic oil chamber is provided with an oil sealing edge of equal width around its perimeter, which is used to form a throttling sealing gap to prevent high-pressure oil from leaking rapidly. The working face support section is provided with annular grooves at the position of each throttling hole. The four sets of annular grooves are arranged at equal intervals along the axial direction of the support bearing. Seal grooves are provided between adjacent annular grooves to prevent oil leakage. The external constant pressure hydraulic oil source enters the throttling hole after passing through the annular grooves. The lower sealing section has an oil return groove on its inner circular surface, and a radial oil return hole is machined at the bottom of the oil return groove. The radial oil return hole is connected to the hydraulic system oil return tank through a pipeline.

[0008] Preferably, the drive mechanism includes a connecting seat and a pair of drive cylinders; the pair of drive cylinders are mounted on the frame, the connecting seat is located at the output end of the pair of drive cylinders, and the output shaft of the cylinder under test is connected to the connecting seat.

[0009] Preferably, the follower mechanism includes a pair of first steel cables, pulleys, and a first tension sensor; the pair of pulleys are both disposed on the first sliding seat, one end of each first steel cable is connected to the connecting seat, and the other end of the first steel cable passes around the pulley and is connected to the bottom of the frame; the first tension sensor is disposed between the first steel cable and the bottom of the frame.

[0010] Preferably, the load compensation mechanism includes a mounting plate, a pair of driving components, a second steel cable, and a second tension sensor; the mounting plate is fixed to the frame, the pair of driving components are mounted on the mounting plate, the second steel cable is disposed between the output end of the driving component and the first sliding seat; the second tension sensor is disposed between the second steel cable and the first sliding seat and is used to detect the tension on the second steel cable.

[0011] Preferably, the swing loading mechanism includes a load decoupling connector and a dynamic loading mechanism; the load decoupling connector is disposed between the output end of the tested cylinder and the connecting seat, and the dynamic loading mechanism is slidably connected to the support column along the length direction of the support column; the output end of the dynamic loading mechanism abuts against the load decoupling connector to provide a radial load on the output shaft of the tested cylinder.

[0012] Preferably, the load decoupling connector includes an upper connecting flange, a cross-hinged core swing body, a lower connecting flange, a lower ear seat, and an upper ear seat; the upper ear seat is connected to the output shaft of the tested cylinder through the upper connecting flange, the lower ear seat is fixed to the connecting seat through the lower connecting flange, the cross-hinged core swing body includes a radial swing pin and a circumferential swing pin arranged perpendicularly to each other, the upper ear seat is rotatably connected to the circumferential swing pin about the axis of the circumferential swing pin, and the lower ear seat is rotatably connected to the radial swing pin about the axis of the radial swing pin.

[0013] Preferably, the dynamic loading mechanism includes multiple second sliding seats, a mounting bracket, a rotating shaft, a cam, a protrusion, a motor, a worm gear, and a worm. The second sliding seats are slidably connected to the support column along the length of the support column and are fixed to the connecting seat. The mounting bracket is fixed to the second sliding seats. The cam is rotatably connected to the mounting bracket via the rotating shaft. The protrusion is disposed in the cross-hinged core swing body. The cam abuts against the protrusion. The motor is mounted on the second sliding seats. The worm gear is coaxially fixed to the rotating shaft. The worm is coaxially connected to the motor output shaft, and the worm gear meshes with the worm.

[0014] In summary, the technical effects and advantages of this invention are as follows: 1. This invention, by setting up a deflection compensation mechanism and a swing loading mechanism, drives the first sliding seat to move synchronously with the output shaft of the tested cylinder through a follower mechanism, so that the support bearing is always at the midpoint of the extended section of the output shaft. A rigid static pressure oil film is formed by the fan-shaped static pressure oil chamber in the support bearing, and the oil chamber pressure is adaptively adjusted to counteract the radial deflection caused by the piston rod's own weight. At the same time, the load decoupling joint of the swing loading mechanism realizes the rigid transmission of the axial main load, completely releasing the overturning torque generated by the radial load. Combined with the dynamic loading mechanism to simulate the dynamic swing radial load of the actual hoisting condition, it eliminates the interference of the additional bending moment caused by deflection on the testing of core performance parameters such as cylinder leakage and starting pressure, ensuring the stability of the test condition and the authenticity of the test data, and making the test condition highly consistent with the actual service condition of the tested cylinder.

[0015] 2. This invention, by setting up a supporting bearing and adopting a three-section coaxial integrated annular sleeve structure, ensures that the inner diameter of each section is completely consistent without any step difference. Four sets of independent fan-shaped static pressure oil chambers are opened on the inner circular surface of the working support section. Each set of oil chambers corresponds to an independent throttling hole and annular grooves arranged axially at equal intervals. The oil sealing edge around the oil chamber forms a throttling sealing gap to establish a stable high-pressure oil film. Adjacent annular grooves are isolated by sealing grooves to prevent oil leakage. Both ends are statically sealed with the first sliding seat through sealing rings. An oil return groove is set at the lower end to uniformly collect leaked oil. This invention achieves adaptive compensation for the self-weight deflection of the output shaft of the tested cylinder in all directions. At the same time, it completely avoids the risk of scratching the piston rod working surface by the bearing end, protects the original performance of the tested cylinder from the influence of the testing process, ensures the long-term stability of the static pressure oil film support stiffness, and improves the accuracy and reliability of deflection compensation.

[0016] 3. This invention, by setting a load decoupling joint, utilizes the radial and circumferential swing pins perpendicularly arranged in the core swing body of the cross hinge to form two mutually perpendicular rotational degrees of freedom. The upper connecting flange is connected to the output shaft of the tested cylinder, and the lower connecting flange is fixed to the connecting seat of the drive mechanism. This allows the axial main load to be rigidly transmitted without loss along the central axis, while the overturning torque generated by the radial load is completely released through the two rotational degrees of freedom. This achieves complete decoupling between the axial main load and the radial dynamic load, controlling the axial loading force fluctuation during the radial load loading process to a very small range, reducing the axial force fluctuation caused by radial loading. At the same time, it can realize the simulation of radial swing in any direction, comprehensively covering various off-center load conditions in the actual service process of the tested cylinder.

[0017] 4. This invention incorporates a follow-up mechanism and a load compensation mechanism. The follow-up mechanism, through the principle of movable pulley transmission, utilizes the cooperation between the first steel cable and the pulley to ensure that the travel of the first sliding seat is always half the extension stroke of the output shaft of the tested cylinder, achieving precise synchronous follow-up without the need for electronic control system intervention. The load compensation mechanism applies a constant upward compensating force to the first sliding seat through the second steel cable, offsetting the additional axial load caused by the weight of the first sliding seat and sliding friction resistance. This ensures that the support bearing is always in the optimal deflection compensation position, significantly improving the deflection compensation effect under long-stroke conditions. At the same time, it completely eliminates the interference of the additional load brought by the follow-up mechanism on the testing of the core performance parameters of the tested cylinder, further ensuring the authenticity and accuracy of the test data. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a first-view perspective three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the overall second-view three-dimensional structure of the present invention; Figure 3 This is a partial cross-sectional three-dimensional structural diagram of the frame of the present invention; Figure 4 This is a three-dimensional enlarged structural schematic diagram of the deflection compensation mechanism of the present invention; Figure 5 This is a three-dimensional enlarged structural diagram of the first sliding seat of the present invention; Figure 6 This is a partially cross-sectional, three-dimensional enlarged structural diagram of the first sliding seat and the supporting bearing of the present invention; Figure 7 This is a partially cross-sectional, magnified, three-dimensional structural diagram of the supporting bearing bush of the present invention. Figure 8 For the present invention Figure 7 Enlarged structural diagram of region A in the middle; Figure 9 This is a three-dimensional enlarged structural schematic diagram of the swing loading mechanism of the present invention; Figure 10 This is a three-dimensional enlarged schematic diagram of a portion of the structure of the swing loading mechanism of the present invention; Figure 11 This is a three-dimensional enlarged structural schematic diagram of the load decoupling connector of the present invention.

[0020] In the diagram: 1. Frame; 2. Support column; 3. Test cylinder; 4. Drive mechanism; 41. Drive cylinder; 42. Connecting seat; 5. Deflection compensation mechanism; 51. First sliding seat; 52. Slide rail; 53. Slider; 54. Support bearing; 541. Upper sealing section; 542. Working surface support section; 543. Lower sealing section; 544. Fan-shaped hydrostatic oil chamber; 545. Oil sealing edge; 546. Annular groove; 547. Throttling orifice; 548. Sealing ring; 549. Oil return groove; 55. Follow-up mechanism; 551. First steel cable; 552. Pulley; 553. First tension sensor; 56. Load compensation 561. Mounting plate; 562. Drive component; 563. Second steel cable; 564. Second tension sensor; 6. Swing loading mechanism; 61. Load decoupling connector; 611. Upper connecting flange; 612. Cross-hinged core swing body; 6121. Radial swing pin; 6122. Circumferential swing pin; 613. Lower connecting flange; 614. Lower ear seat; 615. Upper ear seat; 62. Dynamic loading mechanism; 621. Second sliding seat; 622. Mounting bracket; 623. Rotating shaft; 624. Cam; 625. Protrusion; 626. Motor; 627. Worm gear; 628. Worm. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: Please refer to Figures 1-3 and Figures 5-7The test bench shown includes a hydraulic lifting cylinder, comprising a frame 1, within which a test cylinder 3 and a drive mechanism 4 are installed. The output end of the drive mechanism 4 is connected to the output shaft of the test cylinder 3. Multiple support columns 2 are arranged parallel to each other within the frame 1. A deflection compensation mechanism 5 and a swing loading mechanism 6 are also installed within the frame 1. The deflection compensation mechanism 5 is used to offset the radial deflection generated by the piston rod's own weight in real time, achieving dynamic adaptive compensation throughout the entire stroke. The swing loading mechanism 6 is used to achieve complete decoupling of the axial main load and the radial dynamic load, simulating the dynamic swing radial load in actual lifting conditions. The deflection compensation mechanism 5 includes a first sliding seat 51, a support bearing 54, a follower mechanism 55, and a load compensation mechanism 56. The first sliding seat 51 is slidably connected to the support column 2 along the axis of the support column 2. A through hole is provided on the first sliding seat 51, and the output shaft of the test cylinder 3 is coaxial with it. The support bearing 54 is coaxially sleeved between the output shaft of the tested cylinder 3 and the through hole; a gap is reserved between the inner hole of the support bearing 54 and the outer circular surface of the output shaft of the tested cylinder 3; four sets of fan-shaped hydrostatic oil chambers 544 are opened on the inner circumference of the support bearing 54, and each set of fan-shaped hydrostatic oil chambers 544 is provided with an independent throttling hole 547. The throttling hole 547 is connected to the external constant pressure hydraulic oil source through a high-pressure hose; the follower mechanism 55 is set between the output end of the drive mechanism 4 and the first sliding seat 51; when the drive mechanism 4 drives the output shaft of the tested cylinder 3 to extend or retract, the follower mechanism 55 is allowed to drive the first sliding seat 51 to follow, and the stroke of the first sliding seat 51 is half of the extension or retraction stroke of the output shaft of the tested cylinder 3; the load compensation mechanism 56 is set between the frame 1 and the first sliding seat 51, and is used to offset the additional load generated when the drive mechanism 4 drives the first sliding seat 51 to move.

[0023] It should be noted that before the test, the cylinder under test 3 is first vertically fixed and installed on the top crossbeam of the frame 1, so that the output shaft of the cylinder under test 3 extends downward in the vertical direction, and the end of the output shaft of the cylinder under test 3 is connected to the output end of the drive mechanism 4. At the same time, the output shaft of the cylinder under test 3 is coaxially inserted into the deflection compensation mechanism 5, and the swing loading mechanism 6 is installed at the connection position between the output shaft of the cylinder under test 3 and the drive mechanism 4.

[0024] During the test, the drive mechanism 4 provides the axial main load to the tested cylinder 3, simulating the heavy-load lifting condition in the actual service process of the tested cylinder 3. The deflection compensation mechanism 5 moves synchronously with the extension and retraction of the output shaft of the tested cylinder 3, and the radial deflection generated by the self-weight of the output shaft of the tested cylinder 3 is offset in real time through the hydrostatic oil film structure. The swing loading mechanism 6 applies a radial dynamic load to the output shaft of the tested cylinder 3, simulating the swing load in the actual hoisting condition, and at the same time realizes the complete decoupling of the axial main load and the radial dynamic load.

[0025] This technical solution achieves real-time adaptive compensation for the deflection of the output shaft of the tested cylinder 3 under its own weight throughout the entire stroke using a deflection compensation mechanism 5. Specifically, the follow-up mechanism 55 ensures that the first sliding seat 51 is always at the midpoint of the extended section of the output shaft of the tested cylinder 3, so that the support bearing 54 is always at the midpoint of the extended section of the output shaft of the tested cylinder 3 to provide radial support. A constant pressure hydraulic oil source injects high-pressure oil into the fan-shaped static pressure oil chamber 544, forming a rigid static pressure oil film between the support bearing 54 and the output shaft of the tested cylinder 3. When the output shaft of the hydraulic cylinder 3 experiences radial deflection due to its own weight, the gap of the corresponding sector-shaped hydrostatic oil chamber 544 changes, and the oil chamber pressure is adaptively adjusted to generate a reverse support force to counteract the self-weight deflection. At the same time, the swing loading mechanism 6 can simulate the dynamic swing radial load in actual hoisting conditions and achieve complete decoupling between the axial main load and the radial dynamic load, avoiding interference of the radial load on the axial loading force. The load compensation mechanism 56 can offset the additional load brought by the first sliding seat 51, avoiding interference of the additional load with the performance test accuracy of the hydraulic cylinder 3 under test.

[0026] See Figures 1-4 A slide rail 52 is provided on the support column 2, and the length direction of the slide rail 52 is parallel to the axis of the support column 2. A slider 53 is slidably connected on the slide rail 52, and the slider 53 is fixed to the first sliding seat 51.

[0027] It should be noted that when the first sliding seat 51 moves synchronously with the extension and retraction of the output shaft of the tested cylinder 3, the first sliding seat 51 slides linearly along the slide rail 52 via the slider 53. The slide rail 52 is arranged along the axis of the support column 2, providing a unique motion guide for the sliding of the first sliding seat 51, limiting the radial wobble and circumferential rotation of the first sliding seat 51, and ensuring that the central axis of the through hole of the first sliding seat 51 remains coaxial with the central axis of the output shaft of the tested cylinder 3 during the entire sliding process. This avoids the problem of decreased static pressure oil film stiffness and scraping between the support bearing 54 and the output shaft of the tested cylinder 3 caused by the wobble of the first sliding seat 51, greatly improving the accuracy and stability of deflection compensation, while reducing the frictional resistance during the sliding process and ensuring the smoothness of the follow-up action.

[0028] See Figures 5-7 The support bearing 54 includes an upper sealing section 541, a working surface support section 542, and a lower sealing section 543. The support bearing 54 is a coaxial three-section annular sleeve structure. The upper sealing section 541, the working surface support section 542, and the lower sealing section 543 are coaxially connected in sequence, and the inner diameters of the upper sealing section 541, the working surface support section 542, and the lower sealing section 543 are completely consistent without any step difference. The outer walls of the upper sealing section 541 and the lower sealing section 543 are provided with mounting grooves. A sealing ring 548 is provided in the mounting groove and is used to achieve static sealing between the outer circle of the support bearing 54 and the through hole of the first sliding seat 51 to prevent high-pressure oil from leaking from the mating surface.

[0029] It should be noted that when the support bearing 54 moves synchronously with the first sliding seat 51, the inner diameter of the three-section coaxial structure has no step difference, which can avoid the scraping between the output shaft of the tested cylinder 3 and the end of the support bearing 54 during the extension and retraction process. The sealing ring 548 fills the fitting gap between the outer circle of the support bearing 54 and the through hole of the first sliding seat 51, blocking the leakage path of high pressure oil from the mating surface and ensuring the pressure stability in the fan-shaped static pressure oil chamber 544.

[0030] The three-section coaxial integrated support bearing 54 structure completely avoids the risk of scratching the working surface of the output shaft of the tested cylinder 3 by the inner diameter step, protecting the original performance of the tested cylinder 3 from the influence of the testing process. At the same time, the sealing ring 548 achieves a reliable static seal between the support bearing 54 and the first sliding seat 51, avoiding the pressure drop in the oil chamber caused by high pressure oil leakage, ensuring that the support stiffness of the static pressure oil film is always in a stable state, and improving the long-term reliability of the deflection compensation effect.

[0031] See Figures 7-8 A fan-shaped hydrostatic oil chamber 544 is formed on the inner circular surface of the working face support section 542. Each fan-shaped hydrostatic oil chamber 544 is surrounded by an oil sealing edge 545 of equal width, which is used to form a throttling sealing gap to prevent high-pressure oil from leaking quickly. An annular groove 546 is formed on the working face support section 542 at the position corresponding to each throttling hole 547. The four sets of annular grooves 546 are arranged at equal intervals along the axial direction of the support bearing 54. A sealing groove is set between adjacent annular grooves 546 to isolate them to prevent oil cross-contamination. The external constant pressure hydraulic oil source enters the throttling hole 547 after passing through the annular groove 546. A return oil groove 549 is formed on the inner circular surface of the lower sealing section 543. A radial return oil hole is machined at the bottom of the return oil groove 549. The radial return oil hole is connected to the hydraulic system return oil tank through a pipeline.

[0032] It should be noted that during the test, after the high-pressure oil from the constant pressure hydraulic oil source enters the corresponding annular groove 546, it enters the corresponding sector-shaped static pressure oil chamber 544 through the throttling hole 547. The sealing edge 545 forms a throttling sealing gap between the support bearing 54 and the output shaft of the tested cylinder 3, so that a stable high-pressure oil film is established in the sector-shaped static pressure oil chamber 544. The sealing groove between adjacent annular grooves 546 can prevent oil leakage between different oil chambers, ensuring that the pressure of each group of sector-shaped static pressure oil chambers 544 can be adjusted independently. The oil leaking from the sealing edge 545 flows into the return oil groove 549 and returns to the hydraulic system return oil tank through the radial return oil hole.

[0033] Through the throttling and sealing effect of the sealing edge 545, a stable high-pressure oil film can be established in the fan-shaped static pressure oil chamber 544. When the output shaft of the tested cylinder 3 generates radial deflection, the change in the oil chamber clearance in the corresponding direction will directly trigger the adaptive adjustment of the oil chamber pressure, generating a reverse support force in real time to offset the deflection and achieve fully automatic compensation of self-weight deflection. The equally spaced and mutually isolated annular grooves 546 can completely avoid the problem of oil leakage between different oil chambers, ensuring that the pressure of the four fan-shaped static pressure oil chambers 544 is completely independent, and can achieve adaptive compensation of deflection in all directions. At the same time, the return oil groove 549 can uniformly recover the leaked oil and avoid oil leakage from contaminating the moving parts inside the equipment.

[0034] See Figure 1 , Figure 4 and Figure 9 The drive mechanism 4 includes a connecting seat 42 and a pair of drive cylinders 41; the pair of drive cylinders 41 are mounted on the frame 1, the connecting seat 42 is located at the output end of the pair of drive cylinders 41, and the output shaft of the cylinder under test 3 is connected to the connecting seat 42.

[0035] It should be noted that during the test, a pair of drive cylinders 41 operate synchronously, with their output ends extending or retracting synchronously, driving the connecting seat 42 to move linearly in the vertical direction. The connecting seat 42 is rigidly connected to the end of the output shaft of the cylinder under test 3. The axial thrust generated by the drive cylinder 41 is transmitted to the output shaft of the cylinder under test 3 through the connecting seat 42, providing a stable axial main load for the cylinder under test 3, simulating the heavy-load lifting, pressure holding and alignment conditions in the actual service process of the cylinder under test 3.

[0036] By synchronously driving a pair of symmetrically arranged drive cylinders 41, the axial loading force can be uniformly applied to the connecting seat 42, avoiding the eccentric bending moment caused by unilateral loading, and ensuring the loading accuracy and stability of the axial main load. At the same time, the connecting seat 42 provides a unified connection reference for the output shaft of the tested cylinder 3, the follower mechanism 55, and the swing loading mechanism 6, ensuring the synchronization of the actions of each mechanism and providing a stable foundation for deflection compensation and decoupled loading.

[0037] See Figures 1-4 The follower mechanism 55 includes a pair of first steel cables 551, pulleys 552, and a first tension sensor 553; the pair of pulleys 552 are both disposed on the first sliding seat 51, one end of each first steel cable 551 is connected to the connecting seat 42, and the other end of the first steel cable 551 passes around the pulley 552 and is connected to the bottom of the frame 1; the first tension sensor 553 is disposed between the first steel cable 551 and the bottom of the frame 1.

[0038] It should be noted that when the output shaft of the tested cylinder 3 extends downward, the connecting seat 42 moves downward synchronously with the output shaft, causing one end of the first steel cable 551 to move downward synchronously. The first steel cable 551, through the pulley 552, pulls the first sliding seat 51 to slide downward synchronously along the support column 2. Through the transmission principle of the movable pulley, the travel of the first sliding seat 51 is always half of the extension travel of the output shaft of the tested cylinder 3. When the output shaft of the tested cylinder 3 retracts upward, the load compensation mechanism 56 drives the first sliding seat 51 to move upward synchronously. With the constant length of the first steel cable 551, it always stays at the midpoint of the extension section of the output shaft of the tested cylinder 3. The first tension sensor 553 detects the tension value of the first steel cable 551 in real time and provides feedback on the tension status of the first steel cable 551 to know the additional axial load value caused by the movement of the first sliding seat 51 when the output shaft of the tested cylinder 3 extends or retracts.

[0039] Through the pulley transmission structure, the first sliding seat 51 and the output shaft of the tested cylinder 3 are precisely synchronized and followed. Without the intervention of the electronic control system, the first sliding seat 51 can always be in the midpoint of the extended section of the output shaft, so that the support bearing 54 is always in the optimal position to compensate for the deflection of the output shaft, which greatly improves the deflection compensation effect under long stroke conditions. At the same time, the first tension sensor 553 can monitor the tension of the first steel cable 551 in real time, avoid the deviation of the follow-up stroke caused by the slack of the steel cable, and ensure the accuracy and reliability of the follow-up action.

[0040] See Figures 3-4 The load compensation mechanism 56 includes a mounting plate 561, a pair of drive members 562, a second steel cable 563, and a second tension sensor 564; it is understood that the drive members 562 are existing technology, such as electric actuators; the mounting plate 561 is fixed to the frame 1 (e.g., Figure 1 As shown, a pair of drive units 562 are mounted on the mounting plate 561, and a second steel cable 563 is disposed between the output end of the drive unit 562 and the first sliding seat 51; a second tension sensor 564 is disposed between the second steel cable 563 and the first sliding seat 51 and is used to detect the tension force on the second steel cable 563; it is understood that the first tension sensor 563 and the second tension sensor 564 are both existing technologies and will not be described in detail.

[0041] It should be noted that during the test, the drive component 562 applies a constant upward pulling force to the first sliding seat 51 through the second steel cable 563. The magnitude of the pulling force matches the sum of the weight of the first sliding seat 51 itself, the sliding friction resistance, and other additional loads, completely offsetting the influence of this additional load on the output shaft of the tested cylinder 3. The second tension sensor 564 detects the tension value of the second steel cable 563 in real time and provides feedback on the magnitude of the compensation force to ensure the stability of the compensation force. When the output shaft of the tested cylinder 3 extends and the pulling force detected by the second tension sensor 564 is more than twice the value detected by the first tension sensor 553, the drive component 562 drives its output shaft to extend to offset the additional pulling force. At this time, relying solely on the weight of the first sliding seat 51, it moves with the extension of the output shaft of the tested cylinder 3, thus eliminating the additional axial load brought by the first sliding seat 51. When the output shaft of the tested cylinder 3 shortens, the drive member 562 drives its output shaft to shorten, always keeping the first steel cable 551 in a taut state. Based on the tension detection value of the first tension sensor 553, the drive member 562 is controlled to make the detected tension of the first tension sensor 553 approach zero, so that when the output shaft of the tested cylinder 3 retracts, the first sliding seat 51 moves accordingly, thus offsetting the additional axial load brought by it.

[0042] The load compensation mechanism 56 can completely offset the additional axial load brought by the first sliding seat 51, preventing this additional load from being superimposed on the main axial load of the drive mechanism 4. This prevents the additional load from interfering with the test results of core performance parameters such as internal leakage, starting pressure, and friction coefficient of the tested cylinder 3, ensuring the authenticity and accuracy of the test data. At the same time, the second tension sensor 564 can monitor the magnitude of the compensation force in real time, ensuring the long-term stability of the compensation effect and adapting to the test requirements of cylinders 3 with different strokes and specifications.

[0043] See Figures 1-2 and Figure 4 The swing loading mechanism 6 includes a load decoupling connector 61 and a dynamic loading mechanism 62. The load decoupling connector 61 is disposed between the output end of the tested cylinder 3 and the connecting seat 42. The dynamic loading mechanism 62 is slidably connected to the support column 2 along the length direction of the support column 2. The output end of the dynamic loading mechanism 62 abuts against the load decoupling connector 61 to provide a radial load on the output shaft of the tested cylinder 3.

[0044] It should be noted that during the test, the load decoupling connector 61 rigidly transmits the axial main load of the drive mechanism 4 to the output shaft of the tested cylinder 3. The dynamic loading mechanism 62 applies a radial load to the load decoupling connector 61 to simulate the dynamic swinging radial load borne by the tested cylinder 3 in the actual hoisting condition. The load decoupling connector 61 completely decouples the radial load from the axial main load, so that the radial load only drives the output shaft of the tested cylinder 3 to swing radially and will not be transmitted to the drive mechanism 4.

[0045] The load decoupling joint 61 achieves complete decoupling between the axial main load and the radial dynamic load. This ensures that the axial main load remains stable during the application of the radial dynamic load, avoiding fluctuations in the axial loading force caused by the radial load and ensuring the stability of the test conditions. At the same time, the dynamic loading mechanism 62 can accurately simulate the randomly changing dynamic swing radial load in actual hoisting conditions, making the test conditions highly similar to the actual service conditions of the tested cylinder 3, thus improving the engineering reference value of the test results.

[0046] See Figures 9-11 The load decoupling connector 61 includes an upper connecting flange 611, a cross-hinged core swing body 612, a lower connecting flange 613, a lower ear seat 614, and an upper ear seat 615. The upper ear seat 615 is connected to the output shaft of the tested cylinder 3 through the upper connecting flange 611, and the lower ear seat 614 is fixed to the connecting seat 42 through the lower connecting flange 613. The cross-hinged core swing body 612 includes a radial swing pin 6121 and a circumferential swing pin 6122 that are perpendicular to each other. The upper ear seat 615 is rotatably connected to the circumferential swing pin 6122 around the axis of the circumferential swing pin 6122, and the lower ear seat 614 is rotatably connected to the radial swing pin 6121 around the axis of the radial swing pin 6121.

[0047] It should be noted that during the transmission of the axial main load, the axial thrust of the drive mechanism 4 is rigidly transmitted to the output shaft of the tested cylinder 3 through the lower connecting flange 613, lower ear seat 614, radial swing pin 6121, cross hinge core swing body 612, circumferential swing pin 6122, upper ear seat 615, and upper connecting flange 611. When the dynamic loading mechanism 62 applies a radial load, the radial load drives the upper connecting flange 611, upper ear seat 615, and the output shaft of the tested cylinder 3 to swing around the radial swing pin 6121 or circumferential swing pin 6122. The overturning torque generated by the radial load is completely released by the two mutually perpendicular rotational degrees of freedom and will not be transmitted to the lower connecting flange 613 and the drive mechanism 4.

[0048] By utilizing the two mutually perpendicular rotational degrees of freedom of the cross-joint core swing body 612, rigid and lossless transmission of the axial main load is achieved, while the overturning torque generated by the radial load is completely released. This achieves complete decoupling of the axial and radial loads from a mechanical perspective, which can control the axial loading force fluctuation during the radial load loading process to a very small range, completely solving the problem of axial force fluctuation caused by radial loading. At the same time, it can realize the simulation of radial swing in any direction, comprehensively covering various off-center load conditions in the actual service process of the tested cylinder 3, and improving the comprehensiveness and accuracy of the test.

[0049] Example 2: The technical solution of this example differs from that of Example 1 in that: (See below) Figures 9-10The dynamic loading mechanism 62 includes multiple second sliding seats 621, a mounting bracket 622, a rotating shaft 623, a cam 624, a protrusion 625, a motor 626, a worm gear 627, and a worm 628. The second sliding seats 621 are slidably connected to the support column 2 along the length of the support column 2, and the second sliding seats 621 are fixed to the connecting seat 42. The mounting bracket 622 is fixed to the second sliding seats 621. The cam 624 is rotatably connected to the mounting bracket 622 through the rotating shaft 623. The protrusion 625 is disposed in the cross-hinged core swing body 612, and the cam 624 abuts against the protrusion 625. The motor 626 is mounted on the second sliding seats 621. The worm gear 627 is coaxially fixed to the rotating shaft 623. The worm 628 is coaxially connected to the output shaft of the motor 626, and the worm gear 627 is meshed with the worm 628.

[0050] It should be noted that during the test, the second sliding seat 621 slides synchronously along the support column 2 with the connecting seat 42, ensuring that the cam 624 and the protrusion 625 on the cross-hinged core swing body 612 always remain in contact. When a radial dynamic load needs to be applied, the motor 626 drives the worm 628 to rotate. Through the meshing transmission between the worm wheel 627 and the worm 628, the rotating shaft 623 and the cam 624 rotate synchronously. The contour change of the cam 624 applies a dynamically changing radial force to the cross-hinged core swing body 612 through the protrusion 625, thereby achieving radial load loading of different amplitudes and frequencies.

[0051] Through the meshing transmission of worm gear 627 and worm 628, the self-locking characteristic ensures the stability and controllability of radial loading force, avoiding the deviation of loading amplitude caused by the reverse transmission of radial load. By changing the cam 624 with different profiles, the variation law of radial load can be quickly adjusted, which can accurately reproduce various dynamic swing loads in actual hoisting conditions. At the same time, the second sliding seat 621 moves synchronously with the connecting seat 42, which can ensure that the relative position of the radial force application point and the load decoupling joint 61 is always fixed. No matter how long the output shaft of the tested cylinder 3 extends, the accuracy and stability of radial loading can be guaranteed, which is suitable for the full-condition testing requirements of the ultra-long stroke tested cylinder 3.

[0052] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test bench based on a hydraulic lifting cylinder, comprising a frame (1), wherein a test cylinder (3) and a drive mechanism (4) are disposed within the frame (1), the drive mechanism (4) being used to drive the output shaft of the test cylinder (3) to extend or retract, characterized in that: The frame (1) is provided with multiple support columns (2), and the frame (1) is provided with a deflection compensation mechanism (5) and a swing loading mechanism (6); the swing loading mechanism (6) is used to achieve complete decoupling of axial main load and radial dynamic load; the deflection compensation mechanism (5) includes: The first sliding seat (51) is slidably connected to the support column (2) along the axis of the support column (2); The support bearing (54) has a through hole on the first sliding seat (51), and the output shaft of the tested cylinder (3) is coaxially inserted into the through hole; the support bearing (54) is coaxially sleeved between the output shaft of the tested cylinder (3) and the through hole; the inner circumference of the support bearing (54) has four sets of fan-shaped static pressure oil chambers (544) with independent throttling holes (547), and the throttling holes (547) are connected to the external constant pressure hydraulic oil source through high pressure hoses; And a follower mechanism (55) is provided between the output end of the drive mechanism (4) and the first sliding seat (51); and is used to drive the first sliding seat (51) to move as the output shaft of the tested cylinder (3) extends and retracts; The deflection compensation mechanism (5) further includes a load compensation mechanism (56), which is disposed between the frame (1) and the first sliding seat (51) and is used to offset the additional load generated when the drive mechanism (4) moves the first sliding seat (51); the load compensation mechanism (56) includes a mounting plate (561), a pair of drive members (562), a second steel cable (563), and a second tension sensor (564); the mounting plate (561) is fixed to the frame (1), the pair of drive members (562) are mounted on the mounting plate (561), the second steel cable (563) is disposed between the output end of the drive member (562) and the first sliding seat (51); the second tension sensor (564) is disposed between the second steel cable (563) and the first sliding seat (51) and is used to detect the tension on the second steel cable (563); The swing loading mechanism (6) includes a load decoupling connector (61) and a dynamic loading mechanism (62); the load decoupling connector (61) is disposed between the output end of the tested cylinder (3) and the connecting seat (42), and the dynamic loading mechanism (62) is slidably connected to the support column (2) along the length direction of the support column (2); the output end of the dynamic loading mechanism (62) abuts against the load decoupling connector (61) to provide radial load on the output shaft of the tested cylinder (3).

2. The test bench based on a hydraulic lifting cylinder according to claim 1, characterized in that: The support column (2) is provided with a slide rail (52), and the length direction of the slide rail (52) is parallel to the axis of the support column (2). A slider (53) is slidably connected on the slide rail (52), and the slider (53) is fixed to the first sliding seat (51).

3. The test bench based on a hydraulic lifting cylinder according to claim 1, characterized in that: The support bearing (54) includes an upper sealing section (541), a working surface support section (542), and a lower sealing section (543); the support bearing (54) is a three-section annular sleeve structure with coaxial integration; the upper sealing section (541), the working surface support section (542), and the lower sealing section (543) are connected coaxially in sequence, and the inner diameters of the upper sealing section (541), the working surface support section (542), and the lower sealing section (543) are consistent; the outer walls of the upper sealing section (541) and the lower sealing section (543) are provided with mounting grooves; a sealing ring (548) is provided in the mounting groove, and is used to achieve static sealing between the outer circle of the support bearing (54) and the through hole of the first sliding seat (51) to prevent high-pressure oil from leaking from the mating surface.

4. The test bench based on a hydraulic lifting cylinder according to claim 3, characterized in that: The fan-shaped static pressure oil chamber (544) is opened on the inner circular surface of the working face support section (542). Each fan-shaped static pressure oil chamber (544) is provided with an oil sealing edge (545) of equal width around its perimeter, which is used to form a throttling sealing gap to prevent high pressure oil from leaking rapidly. The working face support section (542) is provided with annular grooves (546) at the position corresponding to each throttle hole (547). The four sets of annular grooves (546) are arranged at equal intervals along the axial direction of the support bearing (54). A sealing groove is provided between adjacent annular grooves (546) to isolate them and prevent oil leakage. The external constant pressure hydraulic oil source enters the throttle hole (547) after passing through the annular grooves (546). The lower sealing section (543) has an oil return groove (549) on its inner circular surface. The bottom of the oil return groove (549) is machined with a radial oil return hole, which is connected to the hydraulic system oil return tank through a pipeline.

5. The test bench based on a hydraulic lifting cylinder according to claim 1, characterized in that: The drive mechanism (4) includes a connecting seat (42) and a pair of drive cylinders (41); the pair of drive cylinders (41) are mounted on the frame (1), the connecting seat (42) is located at the output end of the pair of drive cylinders (41), and the output shaft of the cylinder under test (3) is connected to the connecting seat (42).

6. The test bench based on a hydraulic lifting cylinder according to claim 5, characterized in that: The follower mechanism (55) includes a pair of first steel cables (551), pulleys (552), and a first tension sensor (553); the pair of pulleys (552) are both disposed on the first sliding seat (51), one end of each first steel cable (551) is connected to the connecting seat (42), and the other end of the first steel cable (551) passes around the pulley (552) and is connected to the bottom of the frame (1); the first tension sensor (553) is disposed between the first steel cable (551) and the bottom of the frame (1).

7. The test bench based on a hydraulic lifting cylinder according to claim 1, characterized in that: The load decoupling connector (61) includes an upper connecting flange (611), a cross-hinged core swing body (612), a lower connecting flange (613), a lower ear seat (614), and an upper ear seat (615). The upper ear seat (615) is connected to the output shaft of the tested cylinder (3) through the upper connecting flange (611), and the lower ear seat (614) is fixed to the connecting seat (42) through the lower connecting flange (613). The cross-hinged core swing body (612) includes a radial swing pin (6121) and a circumferential swing pin (6122) arranged perpendicularly to each other. The upper ear seat (615) is rotatably connected to the circumferential swing pin (6122) around the axis of the circumferential swing pin (6122), and the lower ear seat (614) is rotatably connected to the radial swing pin (6121) around the axis of the radial swing pin (6121).

8. The test bench based on a hydraulic lifting cylinder according to claim 7, characterized in that: The dynamic loading mechanism (62) includes multiple second sliding seats (621), a mounting bracket (622), a rotating shaft (623), a cam (624), a protrusion (625), a motor (626), a worm gear (627), and a worm (628); the second sliding seats (621) are slidably connected to the support column (2) along the length direction of the support column (2), and the second sliding seats (621) are fixed to the connecting seat (42), the mounting bracket (622) is fixed to the second sliding seats (621), and the protrusion... The wheel (624) is rotatably connected to the mounting bracket (622) via the rotating shaft (623). The protrusion (625) is disposed in the cross-hinged core swing body (612). The cam (624) abuts against the protrusion (625). The motor (626) is mounted on the second sliding seat (621). The worm wheel (627) is coaxially fixed to the rotating shaft (623). The worm (628) is coaxially connected to the output shaft of the motor (626), and the worm wheel (627) is meshed with the worm (628).

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