Heavy load hydraulic cylinder synchronous extension and retraction driving bridge lifting mechanical system

Abstract

The present application relates to a kind of heavy hydraulic cylinder synchronous extension and contraction drive bridge lifting mechanical system, comprising: at least four groups of hydraulic drive unit, each group of the hydraulic drive unit includes heavy hydraulic cylinder and hydraulic pump station;Supporting box, for fixed connection with bridge main body;Anti-falling device, connecting between the supporting box and bridge foundation;Control system, for controlling the hydraulic pump station and the anti-falling device;Wherein, the cylinder barrel of the heavy hydraulic cylinder is fixedly connected with the supporting box, the hydraulic pump station drives the heavy hydraulic cylinder to extend and retract to drive the supporting box and bridge lifting, the anti-falling device provides mechanical locking when bridge stops.

Description

Technical Field

[0001] This invention relates to the field of bridge opening technology in bridge construction engineering, specifically to a heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system. Background Technology

[0002] A vertical lift bridge is a type of movable bridge that moves vertically as a whole. It is suitable for waterways or ports where land or water traffic is not very heavy but large vessels need to pass. When a vessel needs to pass, the entire bridge is temporarily raised; after the vessel passes, the bridge is closed again, restoring traffic. Its advantages include: lower piers, reduced engineering work on approach bridges and embankments, and lower bridge construction costs.

[0003] Traditional vertical lifting bridges use winch lifting systems, which have advantages such as mature technology and large lifting force. However, in modern bridge projects with large spans and high frequency of use, their drawbacks are becoming increasingly apparent: the equipment is bulky and the civil engineering costs are high; the wire rope maintenance costs are high and its lifespan is limited; the transmission efficiency is relatively low; the stability of operation and positioning accuracy are affected; it has a certain impact on the bridge's appearance; and there are safety hazards such as rope breakage.

[0004] Due to the aforementioned drawbacks, hydraulic jacking systems are gradually becoming the mainstream choice in the design of modern long-span vertical lifting bridges. Hydraulic jacking systems offer advantages such as small size, light weight, smooth operation, easy stepless speed regulation, and overload protection. Summary of the Invention

[0005] The present invention aims to provide a heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system to solve the technical problems of traditional winch lifting systems, such as large equipment size, poor synchronization, low positioning accuracy, insufficient safety, high maintenance cost, and significant impact on bridge landscape.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system includes:

[0008] At least four hydraulic drive units, each of which includes a heavy-duty hydraulic cylinder and a hydraulic pump station;

[0009] Support box, used for fixed connection with the main bridge structure;

[0010] A fall arrestor is connected between the support box and the bridge foundation;

[0011] A control system for controlling the hydraulic pump station and the fall arrestor;

[0012] The cylinder of the heavy-duty hydraulic cylinder is fixedly connected to the support box, the hydraulic pump station drives the heavy-duty hydraulic cylinder to extend and retract to drive the support box and the bridge to rise and fall, and the anti-fall device provides mechanical locking when the bridge stops.

[0013] In some embodiments, the fall arrestor includes:

[0014] A guide sleeve is fixedly connected to the support box, and a guide key is embedded in its inner wall;

[0015] The guide post has a keyway on its outer wall that mates with the guide key, and the upper end of the guide post is fixedly connected to the trapezoidal lead screw by high-strength bolts.

[0016] The lead screw assembly is engaged with the trapezoidal lead screw via a multi-start large helix angle trapezoidal thread.

[0017] The slewing bearing has its upper slewing body fastened to the support housing by bolts, and its lower slewing body fixedly connected to the nut assembly by bolts.

[0018] A brake assembly, the support of which is fixed on the support housing, is used to brake the rotation of the nut assembly;

[0019] The heavy-duty ball joint support is threaded to the lower end of the trapezoidal lead screw and can be horizontally slidably supported on the embedded plate of the bridge foundation.

[0020] The anti-hook plate, welded to the embedded plate of the bridge foundation, is used to restrict the axial movement of the heavy-duty ball joint bearing.

[0021] In some embodiments, the brake assembly includes multiple brakes that energize and release the nut assembly when the bridge is raised or lowered, and de-energize and clamp the disc of the nut assembly to achieve mechanical locking when the bridge stops.

[0022] In some embodiments, the heavy-duty hydraulic cylinder includes a cylinder barrel, a piston rod, a piston, and a built-in magnetostrictive sensor; the extended end of the piston rod is hinged to a ball joint support via a ball joint, and the ball joint support is in horizontal sliding contact with the pre-embedded support of the bridge foundation; the flange end of the cylinder barrel is fastened to the support box by bolts.

[0023] In some embodiments, the piston surface is provided with a copper-based sintered coating to improve pressure resistance and wear resistance.

[0024] In some embodiments, a guiding mechanism is also included, the guiding mechanism comprising:

[0025] The guide bracket is fixedly connected to the support box.

[0026] Balanced framework;

[0027] The guide shaft has one end fixedly connected to the balance frame and the other end slidably inserted through the guide bracket;

[0028] A disc spring assembly is sleeved on the guide shaft and abuts against the balance frame and the guide bracket;

[0029] The roller assembly is mounted on the balance frame;

[0030] The guide rail is fixed to the wall of the bridge structure and rolls in cooperation with the roller assembly;

[0031] The disc spring assembly is used to accommodate temperature deformation of the bridge and buffer guiding loads.

[0032] In some embodiments, the hydraulic pump station includes a proportional relief valve for slow, shock-free hydraulic control during bridge lifting and braking.

[0033] In some embodiments, multiple sets of the hydraulic drive units are symmetrically arranged in machine rooms at both ends of the bridge. Each set of hydraulic drive units works independently and is synchronously lifted and lowered through the control system.

[0034] In some embodiments, a maintenance crane is also included, the maintenance crane comprising a rail, a trolley, and an electric hoist; the rail is fixed to the top of the machine room; the trolley is movably suspended on the rail; and the electric hoist is suspended on the trolley for the installation and maintenance of the equipment.

[0035] In some embodiments, the support box is fixedly connected to the bridge body by flanges and high-strength bolts, and the heavy-duty hydraulic cylinder and the fall arrestor are both fastened to the support box by flanges and bolts.

[0036] This invention provides a heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system, which has the following beneficial effects:

[0037] I. High security

[0038] This invention significantly enhances the safety of bridge lifting systems through multiple safety mechanisms. First, it employs a dual protection design with a hydraulic lock and an anti-fall device. During normal operation, the hydraulic lock maintains pressure; in the event of accidental pressure loss, the anti-fall device immediately locks mechanically, creating redundancy for mutual backup. Second, the anti-fall device's brake uses a power-off braking design, automatically clamping even in the event of a power outage, achieving fail-safe protection. Third, it utilizes a multi-start, large-height trapezoidal thread to convert vertical loads into rotational static torque, requiring only a smaller braking torque to lock hundreds of tons of heavy-duty brakes, significantly reducing the brake capacity requirement. Furthermore, multiple brakes are connected in parallel; even if one group fails, the remaining brakes can still provide sufficient braking torque. Finally, the heavy-duty ball joint support and ball joint can adapt to bridge deformation, ensuring that vertical loads are always transmitted along the central axis of the hydraulic cylinder and lead screw, avoiding damage caused by off-center loading.

[0039] II. High synchronization accuracy

[0040] This invention achieves high-precision synchronous lifting through a precise detection and control system. An integrated magnetostrictive sensor monitors the extension length of each hydraulic cylinder in real time with an accuracy of ±0.1mm, providing accurate feedback signals to the control system. A proportional flow valve enables stepless flow regulation, and combined with a master-slave fuzzy PID control algorithm, the extension and retraction speeds of each hydraulic cylinder can be adjusted in real time, keeping the synchronization error within ±20mm (102m longitudinal bridge direction), far superior to the ±30-40mm of traditional winch systems. Simultaneously, the hydraulic transmission avoids interference from the elastic deformation of the wire rope on the synchronization control, ensuring its stability.

[0041] III. Compact Structure

[0042] This invention employs a direct hydraulic cylinder drive system, eliminating the bulky drum, wire rope, pulley system, and counterweight system of traditional winches, reducing the machine room volume by approximately 50-60%. For example, for a 1200-ton bridge, a traditional winch requires a machine room of 150-200 m² on each side, while this invention requires only 80 m². The machine room height is reduced by approximately 30%, and the width by approximately 40%, minimizing impact on the urban landscape and facilitating integration with surrounding buildings. All drive equipment is housed within the machine room, with no exposed wire ropes or pulley systems, resulting in a superior visual appearance.

[0043] IV. Convenience of Maintenance

[0044] This invention completely eliminates the drawbacks of wire ropes being prone to wear and requiring regular replacement. The heavy-duty hydraulic cylinder piston uses a copper-based sintering coating process, achieving a wear-resistant lifespan of over 10 years, extending the maintenance cycle from six months to two years for traditional winches. The cylinder guide mechanism is equipped with replaceable cylinder liners as wear-resistant bushings; after long-term wear, only the cylinder liner needs to be replaced, without replacing the entire guide shaft. A maintenance crane is installed on the top of the machine room, which can be used for the installation, disassembly, and maintenance of heavy components such as hydraulic cylinders and fall arrestors, eliminating the need for external large lifting equipment. All components are connected by flanges and bolts, facilitating easy assembly and disassembly; replacing a heavy-duty hydraulic cylinder takes only 2 hours, and replacing a cylinder liner also takes only 2 hours.

[0045] V. Stable Operation

[0046] This invention achieves stepless adjustment of hydraulic system pressure and precise control of the slope through a proportional relief valve. During the bridge's lifting, starting, and braking processes, the pressure changes slowly, resulting in smooth start-stop characteristics, no impact vibration, and improved structural lifespan. The lifting speed can be steplessly adjusted within the range of 0.1-1.0 m / min to adapt to different working conditions.

[0047] VI. Highly adaptable

[0048] The guiding mechanism of this invention is equipped with disc springs, which can absorb the thermal expansion and contraction deformation of the bridge caused by temperature changes, with a compensation amount of up to 40mm, thus preventing guide rail overload. Heavy-duty ball joint supports and ball joints allow for ±3° angular displacement and horizontal sliding, accommodating minor deformations and deflections of the bridge during lifting and lowering. Each hydraulic drive unit is independently equipped with a hydraulic pump station, allowing for flexible selection of the number of drive units based on the bridge's tonnage and span, making it suitable for bridges of different sizes.

[0049] VII. Good economic efficiency

[0050] This invention can reduce civil engineering costs by approximately 30-40%, eliminating the need for tall counterweight wells and machine rooms. The hydraulic transmission efficiency can reach over 85%, reducing energy consumption by approximately 20% compared to traditional winch systems. Maintenance cycles are extended, and maintenance costs are reduced by approximately 50%. Considering initial investment, operating energy consumption, and maintenance costs, the total life-cycle cost is approximately 35% lower than that of traditional winch systems.

[0051] In summary, this invention, through the organic combination of hydraulic drive and mechanical locking of the lead screw and nut, provides multiple safety guarantees while ensuring high-precision synchronous lifting. It has comprehensive advantages such as compact structure, convenient maintenance, strong adaptability, and good economy, and is particularly suitable for vertical lifting bridges with large spans, heavy loads, and high frequency of use. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is a schematic elevation view of a heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system.

[0054] Figure 2 A schematic diagram of a bridge lifting mechanical system driven by the synchronous telescopic extension and retraction of heavy-duty hydraulic cylinders.

[0055] Figure 3 A side view of a bridge lifting mechanical system driven by the synchronous telescopic extension and retraction of heavy-duty hydraulic cylinders.

[0056] Figure 4 A partial AA cross-sectional view of a bridge lifting mechanical system driven by synchronous telescopic extension and retraction of heavy-duty hydraulic cylinders.

[0057] Figure 5 Partial BB cross-sectional view of a bridge lifting mechanical system driven by synchronous telescopic extension and retraction of heavy-duty hydraulic cylinders.

[0058] Figure 6 This is a floor plan of the equipment room for the bridge lifting machinery system.

[0059] Figure 7 This is a schematic diagram of a fall protection device.

[0060] Figure 8 This is a schematic diagram for repairing a crane.

[0061] Figure 9 This is a diagram of a heavy-duty hydraulic cylinder.

[0062] Figure 10 This is a schematic diagram of the guiding device.

[0063] Illustrations: 1-Maintenance crane; 2-Heavy-duty hydraulic cylinder; 3-Hydraulic pump station; 4-Guiding mechanism; 5-Fall protection device; 6-Support housing; 7-Guide key; 8-Slewing bearing; 9-Brake assembly; 10-Screw nut assembly; 11-Trapezoidal screw; 12-Reverse hook plate; 13-Heavy-duty ball joint support; 14-Guide sleeve; 15-Guide column; 16-Electric hoist; 17-Traveling crane; 18-Railway; 19-Magnetostrictive sensor; 20-Cylinder barrel; 21-Piston rod; 22-Spherical joint; 23-Spherical joint support; 24-Piston; 25-Guide bracket; 26-Disc spring assembly; 27-Cylinder liner; 28-Guide shaft; 29-Balance frame; 30-Roller assembly; 31-Guide rail. Detailed Implementation

[0064] 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.

[0065] Example 1

[0066] like Figures 1-10 As shown, a heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system includes at least four sets of hydraulic drive units, four support boxes 6, four sets of anti-fall devices 5, and a shared control system. Each set of hydraulic drive units includes two heavy-duty hydraulic cylinders 2 and a set of hydraulic pump stations 3; the support boxes 6 are fixedly connected to the main body of the bridge; the anti-fall devices 5 are connected between the support boxes 6 and the bridge foundation; the control system is used to control the hydraulic pump stations 3 and the anti-fall devices 5; wherein, the cylinder of the heavy-duty hydraulic cylinder 2 is fixedly connected to the support box 6, the hydraulic pump station 3 drives the heavy-duty hydraulic cylinder 2 to telescopically extend and retract to drive the support boxes 6 and the bridge to lift and lower, and the anti-fall devices 5 provide mechanical locking when the bridge stops.

[0067] To address the technical issues of traditional winch systems' bulky size and poor synchronization, the drive system was designed with a direct connection between the hydraulic drive unit and the support housing. The bridge's lifting and lowering are directly driven by the extension and retraction of hydraulic cylinders, eliminating the bulky winch, wire rope, and counterweight system. This reduces the machine room size by more than 50%, while the inherent precise controllability of the hydraulic system provides a foundation for high-precision synchronization. To address safety concerns, an independent fall arrestor was installed, providing mechanical locking when the bridge stops. This, combined with the hydraulic lock in the hydraulic system, creates dual protection, significantly improving safety.

[0068] Hydraulic pump station 3 is connected to heavy-duty hydraulic cylinder 2 via pipeline. The cylinder barrel of heavy-duty hydraulic cylinder 2 is fixedly connected to support box 6 via flange, and support box 6 is fixedly connected to the bridge main body via flange. When the hydraulic pump station supplies oil, the hydraulic cylinder extends and retracts, and the cylinder barrel drives the support box and the bridge to rise and fall. The upper end of the fall arrestor 5 is connected to the support box, and the lower end is supported on the bridge foundation. It moves with the bridge during the lifting and lowering process and locks when stopped.

[0069] In some embodiments, the fall arrestor 5 includes: a guide sleeve 14, fixedly connected to the support housing 6, with a guide key 7 embedded in its inner wall; a guide post 15, with a keyway on its outer wall that mates with the guide key 7, the guide post 15 being fixedly connected to the upper end of the trapezoidal lead screw 11 by high-strength bolts; a lead screw assembly 10, which mates with the trapezoidal lead screw 11 by a multi-start large-height trapezoidal thread; a slewing bearing 8, the upper slewing body of which is bolted to the support housing 6, and the lower slewing body of which is bolted to the lead screw assembly 10; a brake assembly 9, the support of which is fixed to the support housing 6 for braking the rotation of the lead screw assembly 10; a heavy-duty ball joint bearing 13, which is threadedly connected to the lower end of the trapezoidal lead screw 11 and can be horizontally slidably supported on the embedded plate of the bridge foundation; and a reverse hook plate 12, which is welded to the embedded plate of the bridge foundation for limiting the axial movement of the heavy-duty ball joint bearing 13.

[0070] To address the technical challenges of locking heavy loads with low torque and improving safety redundancy, the fall arrestor is configured with the aforementioned screw-nut assembly structure. Utilizing a multi-start, large-helix-angle trapezoidal thread, the vertical load is converted into a rotational static torque, allowing for locking of hundreds of tons of load with only a small braking torque, significantly reducing the brake capacity. To solve the problem of adaptive load transfer, the heavy-duty ball joint support is configured as a horizontal sliding support, accommodating horizontal bridge displacement. Simultaneously, the ball joint structure allows for a certain angular displacement, ensuring that the load is always transmitted along the screw's central axis. To prevent screw rotation, a guide key and guide post are fitted with a keyway to ensure the trapezoidal screw remains stationary and does not rotate.

[0071] The guide sleeve 14 is fixed to the support housing 6. The guide key 7 is embedded in the inner wall of the guide sleeve and slides in cooperation with the keyway of the guide post 15, so that the guide post can only move up and down but cannot rotate. The guide post is fixed to the upper end of the trapezoidal lead screw 11, so the trapezoidal lead screw is also constrained to not rotate. The lead screw nut assembly 10 is screwed into the trapezoidal lead screw through a multi-start large-height trapezoidal thread. The lead screw nut assembly is connected to the support housing through the slewing bearing 8. Therefore, when the support housing is raised or lowered, the lead screw nut assembly is forced to rotate along the lead screw and move up and down. The brake assembly 9 is fixed to the support housing and can clamp the disc of the lead screw nut assembly. The heavy-duty ball joint support 13 is connected to the lower end of the lead screw and sits on the foundation embedded plate. It can slide horizontally, and the anti-hook plate prevents it from axially dislodging.

[0072] In some embodiments, the brake assembly 9 includes multiple brakes that energize and release the nut assembly 10 when the bridge is raised or lowered, and de-energize and clamp the disc of the nut assembly 10 to achieve mechanical locking when the bridge stops.

[0073] To achieve fail-safe protection, the brakes are configured as normally closed structures that open when energized and brake when de-energized. This ensures that even in the event of an unexpected power outage, the brakes will automatically engage, preventing the bridge from collapsing and significantly improving safety. To enhance reliability, multiple brakes are connected in parallel; even if one fails, the others can still provide sufficient braking torque.

[0074] Working process: The control system controls the energization and de-energization of the brake according to the working conditions. When lifting, the brake is energized and opened, allowing the nut to rotate freely; when stopping, the brake is de-energized and clamped, locking the nut.

[0075] In some embodiments, the heavy-duty hydraulic cylinder 2 includes a cylinder barrel 20, a piston rod 21, a piston 24, and a built-in magnetostrictive sensor 19; the extended end of the piston rod 21 is hinged to a ball joint support 23 via a ball joint 22, and the ball joint support 23 is in horizontal sliding contact with the pre-embedded support of the bridge foundation; the flange end of the cylinder barrel 20 is fastened to the support box 6 by bolts.

[0076] To achieve precise position detection and adaptive alignment, a magnetostrictive sensor is installed inside the hydraulic cylinder, providing real-time feedback on the piston rod position and accurate signals for synchronous control. To prevent damage to the hydraulic cylinder from eccentric loads, a ball joint is installed at the end of the piston rod, allowing for a certain angle of oscillation to ensure that the vertical load is aligned with the piston rod axis. Simultaneously, the ball joint support slides horizontally with the pre-embedded support, accommodating the horizontal displacement of the bridge. The piston rod strength is sufficient to withstand both axial and horizontal forces simultaneously.

[0077] Working process and connection relationship: The magnetostrictive sensor 19 is installed inside the piston rod or on the cylinder to detect displacement in real time. The piston rod 21 is connected to the ball joint support 23 via the ball joint 22. The ball joint support sits on the pre-embedded support in the foundation and can slide horizontally. The cylinder 20 flange is fixedly connected to the support box 6. When hydraulic oil pushes the piston, the cylinder moves relative to the piston rod, thereby driving the support box to rise and fall.

[0078] In some embodiments, the piston 24 is provided with a copper-based sintered coating to improve its pressure resistance and wear resistance.

[0079] To address the wear problem between the piston and cylinder under heavy-duty conditions, a copper-based sintered coating is applied to the piston surface. This coating features a low coefficient of friction, high wear resistance, and good impact resistance, significantly extending the life of the hydraulic cylinder.

[0080] In some embodiments, a guide mechanism 4 is further included, the guide mechanism 4 comprising: a guide bracket 25, fixedly connected to the support box 6; a balance frame 29; a guide shaft 28, one end of which is fixedly connected to the balance frame 29, and the other end which is slidably passed through the guide bracket 25; a disc spring assembly 26, sleeved on the guide shaft 28 and abutting between the balance frame 29 and the guide bracket 25; a roller assembly 30, mounted on the balance frame 29; and a guide rail 31, fixed to the wall of the bridge structure and in rolling cooperation with the roller assembly 30; the disc spring assembly 26 is used to adapt to the temperature deformation of the bridge and buffer the guiding load.

[0081] To ensure the bridge's vertical lifting is stable and adaptable to temperature deformation, a guide mechanism is installed, employing disc springs as elastic compensation elements. To address the replacement issue of worn guide components, a replaceable cylinder liner 27 is provided on the guide bracket 25. The guide shaft 28 passes through and slides with the cylinder liner 27. As a wear-resistant bushing, only the cylinder liner needs replacement after wear, eliminating the need to replace the guide shaft and reducing maintenance costs.

[0082] The guide bracket 25 is fixed to the support box 6. The guide bracket has a guide hole into which a cylinder liner 27 is fitted. One end of the guide shaft 28 is fixedly connected to the balance frame 29, and the other end passes through the cylinder liner 27 and can slide axially. A disc spring assembly 26 is fitted onto the guide shaft, located between the balance frame and the guide bracket, and is in a pre-compressed state. The roller assembly 30 is mounted on the balance frame and rolls in contact with the guide rail 31 fixed to the wall. When the bridge rises or falls, the rollers roll along the guide rail to ensure verticality; when the bridge expands or contracts due to temperature changes, the guide shaft slides within the cylinder liner, and the disc spring assembly compresses or rebounds, absorbing displacement and maintaining the contact force between the rollers and the guide rail; under lateral loads, the disc spring assembly acts as a buffer.

[0083] In some embodiments, the hydraulic pump station 3 includes a proportional relief valve for achieving slow, shock-free hydraulic control during bridge lifting and braking.

[0084] To address the start-stop shock issue, a proportional relief valve and a proportional flow valve are installed in the hydraulic pump station. By controlling the input signals of the control valves, the system pressure and flow rate can be steplessly adjusted and the slope controlled, thereby achieving a smooth start-up and braking process.

[0085] In some embodiments, multiple sets of the hydraulic drive units are symmetrically arranged in machine rooms at both ends of the bridge. Each set of hydraulic drive units works independently and is synchronously lifted and lowered through the control system.

[0086] To achieve smooth lifting and lowering of long-span bridges, multiple sets of hydraulic drive units are symmetrically arranged at both ends of the bridge. Each set is driven independently and coordinated and synchronized by the control system to ensure that the bridge deck is level and avoid tilting or jamming.

[0087] In some embodiments, the system further includes a maintenance crane 1, which includes a rail 18, a trolley 17, and an electric hoist 16; the rail 18 is fixed to the top of the machine room; the trolley 17 is movably suspended on the rail 18; and the electric hoist 16 is suspended on the trolley 17 for the installation and maintenance of the equipment.

[0088] To address the issue of inspecting and hoisting heavy components within the computer room, a maintenance crane is installed on the roof of the computer room. This crane can easily lift components such as hydraulic cylinders and fall arrestors without the need for external hoisting equipment, thus improving maintenance convenience.

[0089] In some embodiments, the support box 6 is fixedly connected to the bridge body by flanges and high-strength bolts, and the heavy-duty hydraulic cylinder 2 and the fall arrestor 5 are both fastened to the support box 6 by flanges and bolts.

[0090] To ensure reliable connection and ease of assembly and disassembly, flanges and high-strength bolts are used for connection, which ensures reliable force transmission, convenient assembly and disassembly, and easy maintenance and replacement.

[0091] This invention discloses a heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system. Its working principle is based on a dual guarantee mechanism of "hydraulic drive lifting + screw and nut mechanical locking," achieving smooth vertical lifting of the bridge through the coordinated work of multiple sets of hydraulic cylinders. The working principle is described in detail below from four dimensions: system composition, lifting process, locking state, and start-up transition.

[0092] I. System Composition and Basic Working Logic

[0093] This invention symmetrically arranges four sets of machine rooms at both ends of the bridge, with each set of machine rooms housing an independent hydraulic drive unit. Each drive unit includes a heavy-duty hydraulic cylinder 2, a hydraulic pump station 3, a fall arrestor 5, a guide mechanism 4, a support box 6, and a control system. Its basic working logic is as follows:

[0094] Power source: Hydraulic pump station 3 provides high-pressure oil to drive the extension and retraction of heavy-duty hydraulic cylinder 2;

[0095] Force transmission: The cylinder 20 of the heavy-duty hydraulic cylinder 2 is fixedly connected to the support box 6, and the support box 6 is fastened to the main body of the bridge through a flange. Therefore, the extension and retraction of the hydraulic cylinder is directly converted into the lifting and lowering motion of the bridge.

[0096] Safety guarantee: The fall arrestor 5 is connected in parallel between the support box 6 and the bridge foundation, providing independent mechanical locking when the bridge stops, forming a double protection with the hydraulic lock of the hydraulic system;

[0097] Guiding and stabilizing: The roller assembly 30 of the guiding mechanism 4 rolls along the guide rail 31 to ensure that the bridge rises and falls vertically without tilting, while the disc spring assembly 26 adapts to temperature deformation.

[0098] Control core: The control system acquires the position signal of the magnetostrictive sensor 19 and adjusts the extension and retraction speed and synchronization of the hydraulic cylinder through the proportional relief valve.

[0099] II. Working principle of the lifting process

[0100] When the bridge needs to be raised or lowered, the system operates according to the following steps:

[0101] Step 1: Release the brake

[0102] The control system sends an energizing command to the brake assembly 9 of the fall arrestor 5, the brake opens, and the disc of the nut assembly 10 is released. At this time, the nut assembly 10 is in a free state and can rotate with the movement of the support housing 6.

[0103] Step 2: Hydraulic Drive

[0104] When hydraulic pump station 3 starts, the proportional relief valve slowly increases the pressure at the set slope, and the high-pressure oil enters the rodless chamber (when rising) or rod chamber (when falling) of heavy-duty hydraulic cylinder 2. The piston rod 21 extends or retracts under the action of oil pressure. Since the ball joint support 23 at the end of the piston rod 21 is in sliding contact with the foundation embedded plate, and the cylinder 20 is fixedly connected to the support box 6, the reaction force drives the cylinder 20 to drive the support box 6 and the bridge to rise or fall.

[0105] Step 3: Mother wire moves with the mother

[0106] During the bridge's lifting and lowering process, the nut assembly 10 of the fall arrestor 5 is connected to the support box 6 via the slewing bearing 8, and therefore rises and falls together with the support box 6. Since the trapezoidal lead screw 11 is constrained to a stationary position by the guide key 7 and guide post 15, the nut assembly 10 must rotate along the thread of the trapezoidal lead screw 11 during lifting and lowering. The design of the multi-start, large-helix-angle trapezoidal thread results in low frictional resistance during this rotational motion (measured friction coefficient approximately 0.12-0.15), preventing significant additional resistance to the bridge's lifting and lowering.

[0107] Step 4: Guidance and Synchronization

[0108] During the lifting process, the roller assembly 30 of the guide mechanism 4 rolls up and down along the guide rail 31, limiting the lateral displacement of the bridge and ensuring vertical lifting accuracy. Simultaneously, the magnetostrictive sensor 19 detects the extension length of each hydraulic cylinder in real time and feeds the signal back to the PLC. The control system employs a master-slave fuzzy PID algorithm, using one set of hydraulic cylinders as a reference to adjust the proportional relief valve pressure of the other hydraulic cylinders in real time, ensuring that the extension speed of each cylinder remains consistent and achieving high-precision synchronization.

[0109] Step 5: Smooth braking

[0110] As the system approaches the target position, the proportional relief valve slowly reduces pressure at a set slope, causing the hydraulic cylinder to decelerate. Upon reaching the target position, the hydraulic pump station stops supplying oil, and the hydraulic lock automatically engages to prevent the hydraulic cylinder from retracting. Subsequently, the brake assembly 9 is de-energized, clamping the disc of the nut assembly 10 to complete the mechanical locking.

[0111] III. Working principle of the stop-lock state

[0112] When a bridge needs to maintain a certain height for an extended period, the system enters a locked state. Its working principle is as follows:

[0113] 1. Load transfer

[0114] The control system commands the heavy-duty hydraulic cylinder 2 to retract slightly (approximately 1-2 mm) to relieve the load, thus removing the weight of the bridge from the hydraulic cylinder. At this point, the vertical load of the bridge is transferred to the fall arrestor 5 via the support box 6. The specific force transmission path is as follows:

[0115] Support box 6 → Slewing bearing 8 → Threaded nut assembly 10 → Trapezoidal threaded rod 11 → Heavy-duty ball joint bearing 13 → Bridge foundation.

[0116] 2. Mechanical locking principle

[0117] When the lead screw assembly 10 is subjected to a vertical load, the trapezoidal lead screw 11 has a large thread helix angle (approximately 12.5°), which causes it to slide down along the thread. This downward trend causes the lead screw assembly 10 to rotate, but since the brake assembly 9 has clamped the disc of the lead screw assembly 10, the rotation is prevented, thus achieving static equilibrium.

[0118] 3. Torque balance

[0119] The total braking torque provided by multiple brakes ensures that the nut assembly 10 will not rotate or slip.

[0120] 4. Reaction torque transmission

[0121] The trapezoidal lead screw 11 is affected by the static rotational torque of the lead screw assembly 10, generating a counter-rotational torque. This torque is transmitted upward through the trapezoidal lead screw 11 body to the guide post 15, and then through the guide key 7 to the support housing 6, forming a complete force-closed system. This design ensures that the locking force is completely balanced within the mechanical structure and does not depend on external energy.

[0122] IV. Working Principle of Start-up Conversion

[0123] When the bridge transitions from a static state to a lifting state, the system operates according to the following principles:

[0124] Step 1: Hydraulic load-bearing

[0125] Hydraulic pump station 3 supplies hydraulic fluid, and heavy-duty hydraulic cylinder 2 extends slightly (approximately 1-2 mm), causing cylinder barrel 20 to slightly lift support housing 6. At this time, the control system monitors the hydraulic cylinder pressure in real time.

[0126] Step 2: Load Assessment

[0127] When the pressure sensor detects that the hydraulic cylinder pressure has reached the rated load, it indicates that the hydraulic cylinder has fully borne the weight of the bridge, and at this time the trapezoidal screw 11 of the fall arrestor 5 has been unloaded.

[0128] Step 3: Release the brake

[0129] The hydraulic lock maintains the current pressure, then the brake assembly 9 is energized to open, releasing the nut assembly 10.

[0130] Step 4: Smooth transition

[0131] After confirming that the brake is fully open, the hydraulic lock opens, the proportional relief valve pressurizes at the set slope, and normal lifting and lowering begins. The entire conversion process is smooth and without shock, and the conversion time is approximately 3-5 seconds.

[0132] V. Safety Coordination Principle of Fall Arrestors

[0133] The fall arrestor 5 is the core safety mechanism of this invention, and its design embodies the principles of "fail-safe" and "multiple redundancy":

[0134] 1. Power-off braking principle

[0135] The brake assembly 9 adopts a normally closed design, meaning it opens when energized and brakes when de-energized. This means that even in the event of an unexpected power outage, the brake will automatically clamp, preventing the bridge from collapsing.

[0136] 2. Principle of low-torque locking under heavy load

[0137] By utilizing the large helix angle thread of the trapezoidal lead screw, the vertical load is converted into a rotational static torque. Since the braking torque acts on the rotating lead screw assembly 10, rather than directly on the linearly moving bridge, only a small braking torque is needed to lock a heavy load of hundreds of tons. This "torque amplification" effect significantly reduces the capacity requirement of the brake.

[0138] 3. Multiple force transmission paths

[0139] During normal lifting and lowering, the load is borne by the hydraulic cylinder; when stopped and locked, the load is borne by the fall arrestor; in an emergency, both systems can bear the load simultaneously. This multi-path force transmission design ensures that even if any single component fails, other components still guarantee safety.

[0140] VI. Temperature Adaptation Principle of the Guiding Mechanism

[0141] The design of the disc spring assembly 26 in the guide mechanism 4 embodies the principle of adaptive response to temperature deformation:

[0142] 1. Thermal expansion and contraction compensation

[0143] The steel structure of a bridge will change length when the temperature changes. The compressible stroke of the disc spring assembly 26 can absorb the thermal expansion and contraction deformation of the bridge.

[0144] 2. Load buffer

[0145] When the bridge generates lateral forces due to wind loads, eccentric loads, etc., the roller assembly 30 transmits the force to the balance frame 29, and then compresses the disc spring assembly 26 through the guide shaft 28 to buffer the impact load and avoid excessive additional force on the guide rail and the wall.

[0146] 3. Self-balancing regulation

[0147] The balance frame 29 is suspended on the guide bracket 25 by disc spring assemblies 26 on both sides, which can automatically adjust the compression on the left and right sides to ensure that the contact force between the four rollers and the guide rail is uniform and avoid uneven wear.

[0148] VII. Synchronous Control Principle

[0149] The synchronous control of this invention adopts a control strategy of "position closed loop + pressure feedforward":

[0150] 1. Position detection

[0151] The magnetostrictive sensor 19 detects the extension length of each hydraulic cylinder in real time with an accuracy of ±0.1mm, providing precise feedback signals for the control system.

[0152] 2. Deviation Calculation

[0153] The control system uses the average extension length of all hydraulic cylinders as the target value and calculates the deviation of each cylinder from the target value. When the deviation exceeds a set threshold, synchronization adjustment is initiated.

[0154] 3. Speed ​​Adjustment

[0155] For hydraulic cylinders that extend too quickly, the control system reduces the set pressure of their proportional relief valve, thereby decreasing the oil supply flow; for hydraulic cylinders that extend too slowly, the set pressure of the proportional relief valve is increased, thereby increasing the oil supply flow. Through this "pressure following" method, fine-tuning of the speed of each cylinder is achieved.

[0156] 4. Destination Location

[0157] As the system approaches the target position, it automatically switches to closed-loop position control, and all hydraulic cylinders decelerate synchronously at the slowest cylinder speed until they reach the target position at the same time, ensuring that the bridge deck is level.

[0158] The preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. This embodiment takes a vertical lifting bridge with a main span of 102 meters and a total weight of approximately 3,600 tons as the application background, and specifically explains the structure, connection relationship, working principle, and effect of the heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system described in the present invention.

[0159] I. Overall Arrangement

[0160] like Figures 1 to 10 As shown, four independent machine rooms are set up at both ends of the bridge, and each machine room houses a set of hydraulic drive units. Each set of hydraulic drive units includes:

[0161] Two sets of heavy-duty hydraulic cylinders 2 are symmetrically installed on both sides of the machine room;

[0162] A set of 3 hydraulic pump stations, independently configured, is located in the middle of the machine room;

[0163] A set of fall arrestor 5 is installed between two sets of hydraulic cylinders;

[0164] Three sets of guiding mechanisms 4, two of which are arranged outside the hydraulic cylinder and one of which is arranged outside the fall arrestor;

[0165] A support box 6 is fixedly connected to the main body of the bridge via flanges and high-strength bolts;

[0166] A control system with a distributed architecture is used, with the PLC master station located in the central control room and remote I / O slave stations in each machine room.

[0167] Each computer room is equipped with a maintenance crane 1 on the top for the installation and maintenance of equipment.

[0168] II. Detailed Structure of Heavy-Duty Hydraulic Cylinders

[0169] like Figure 9 As shown, the heavy-duty hydraulic cylinder 2 is the core driving component of the system, and its specific structure is as follows:

[0170] Cylinder 20: Made of high-strength seamless steel pipe, with a honed inner bore. A flange is located at the bottom of the cylinder, which is securely connected to the support housing 6 using high-strength bolts.

[0171] Piston rod 21: Surface chrome-plated with a plating thickness of 0.03–0.05 mm to improve wear resistance and corrosion resistance. The extended end of the piston rod is machined with a ball head to mate with ball joint 22.

[0172] Piston 24: It has an integrated structure with the piston rod, and the outer circumference is provided with two sealing grooves and a guide groove. The piston surface adopts a copper-based sintering coating with a coating thickness of 0.3-0.5mm and a friction coefficient ≤0.08. It has excellent friction reduction and impact resistance, and can significantly improve the wear life under heavy-load reciprocating motion.

[0173] Spherical hinge 22 and spherical hinge support 23: The end of the piston rod is hinged to the spherical hinge support 23 via the spherical hinge 22. The spherical hinge support 23 sits on the embedded support of the bridge foundation and can slide horizontally to accommodate horizontal displacement of the bridge caused by temperature changes or loads. The spherical hinge structure allows the piston rod to swing within a range of ±3°, ensuring that the piston rod always bears axial force and avoiding eccentric loading.

[0174] Magnetostrictive sensor 19: Built into the center hole of the piston rod, the sensor probe passes through the inside of the piston rod, and the magnetic ring is fixed to the bottom of the cylinder. The sensor has a measurement accuracy of ±0.1mm, outputs a 4-20mA analog signal or an SSI digital signal, and provides real-time feedback on the absolute position of the piston rod, providing accurate displacement information for the control system.

[0175] Main design parameters:

[0176] Cylinder inner diameter: 600mm

[0177] Piston rod diameter: 500mm

[0178] Working stroke: 2560mm

[0179] Rated working pressure: 25MPa

[0180] Rated thrust per cylinder: 570t

[0181] III. Detailed Structure of Fall Protection Device

[0182] like Figure 7 As shown, the fall arrestor 5 is the core safety feature of this invention, and its specific structure is as follows:

[0183] Guide sleeve 14: It has a cylindrical structure, and its upper end is fastened to the support box 6 with high-strength bolts via a flange. The inner wall of the guide sleeve is machined with a keyway along the axial direction for inserting the guide key 7.

[0184] Guide key 7: Heat-treated, embedded in the keyway of guide sleeve 14 and fixed with set screws. Guide key 7 slides in the keyway of guide post 15, allowing the guide post to move up and down but not rotate.

[0185] Guide post 15: The outer wall is machined with a keyway that mates with the guide key 7. The lower end of the guide post is fixedly connected to the upper end of the trapezoidal lead screw 11 by high-strength bolts.

[0186] Trapezoidal lead screw 11: thread helix angle approximately 12.5°, surface hardened to HRC45-50. The lower end of the lead screw is machined with a threaded section for connecting to the heavy-duty ball joint support 13.

[0187] Thread nut assembly 10: includes a thread nut body and a housing. The thread nut body is cast from ZCuSn10P1 tin bronze and has an internal thread that mates with the trapezoidal thread rod 11. The thread nut housing is connected to the support box 6 via a slewing bearing 8.

[0188] Slewing bearing 8: Its upper slewing body is fastened to the support housing 6 by bolts, and its lower slewing body is fastened to the outer shell of the nut assembly 10 by bolts. The slewing bearing enables the nut assembly 10 to both rise and fall with the support housing and rotate relative to the support housing.

[0189] Brake assembly 9: Composed of multiple normally closed brakes, symmetrically arranged around the disc of the nut assembly 10. The brake support is fixed on the support housing 6. When energized, the brake friction pads open, and the nut assembly 10 can move up and down with the hydraulic cylinder; when braking, the friction pads clamp the disc of the nut assembly 10 to achieve mechanical locking.

[0190] Heavy-duty ball joint support 13: The lower end is spherical, which slides in contact with the spherical seat on the foundation embedded plate, and can accommodate angular displacement of ±2°. The support is connected to the lower end of the trapezoidal screw 11 by a thread and is secured with a lock nut. A stainless steel-PTFE sliding plate with a friction coefficient ≤0.08 is provided between the bottom surface of the support and the embedded plate, allowing for horizontal sliding.

[0191] Anti-hook plate 12: 40mm thick, Q355B steel, welded to the foundation embedded plate. The upper end of the anti-hook plate hooks onto the upper edge of the heavy-duty ball joint support 13, restricting its axial movement but not its horizontal sliding.

[0192] IV. Detailed Structure of the Guiding Mechanism

[0193] like Figure 10 As shown, the guide mechanism 4 is used to ensure the straightness of the bridge's vertical lifting and lowering and to adapt to temperature deformation. Its specific structure is as follows:

[0194] Guide bracket 25: A welded structural component, fixedly connected to the support housing 6 by bolts. Guide holes are machined on the bracket for mounting cylinder liners 27.

[0195] Cylinder liner 27: The cylinder liner is press-fitted into the guide hole of the guide bracket 25 and secured with a set screw. As a wear-resistant bushing, the cylinder liner can be replaced separately after wear, without needing to replace the guide bracket or guide shaft.

[0196] Guide shaft 28: One end is fixedly connected to the balance frame 29 via a flange, and the other end passes through the cylinder liner 27 and can slide axially. The clearance between the guide shaft and the cylinder liner is H7 / f6 to ensure smooth movement.

[0197] Disc spring assembly 26: Eight disc springs are stacked in parallel (4 discs per assembly). The disc spring assembly is sleeved on the guide shaft 28, located between the balance frame 29 and the guide bracket 25, and is in a pre-compressed state (pre-compression amount 15mm). The total stroke of the disc spring assembly can absorb the thermal expansion and contraction deformation of the bridge and buffer lateral loads.

[0198] Balance frame 29: A welded frame structure for mounting the roller assembly 30. The two sides of the frame are connected to the disc spring assembly via guide shafts 28, and can float relative to the guide bracket 25.

[0199] Roller assembly 30: comprises multiple polyurethane rollers. The rollers are mounted on the balance frame 29 via pins and are free to rotate. The rollers make rolling contact with the guide rail 31.

[0200] Guide rail 31: Utilizing crane steel rails, it is fixed to the bridge structure wall via pressure plates and pre-embedded bolts. The working surface of the guide rail undergoes precision grinding to ensure smooth rolling.

[0201] V. Detailed Structure of Crane Maintenance

[0202] like Figure 8 As shown, maintenance crane 1 is used for the installation and maintenance of equipment in the machine room, and its specific structure is as follows:

[0203] Track 18: I-beams or H-beams, fixed to the concrete beam at the top of the machine room with pre-embedded bolts, with two tracks arranged in parallel.

[0204] The overhead crane 17 consists of end beams and a main beam. The end beams are equipped with wheels and can move on the track 18. The crane span is determined based on the width of the machine room; in this embodiment, the span is 4.5m.

[0205] Electric hoist 16: Lifting capacity of 10 tons, suspended below the main beam of the overhead crane 17, and can move laterally along the main beam. The lifting speed of the electric hoist is adjustable, and it is equipped with upper and lower limits and overload protection.

[0206] VI. Hydraulic System Configuration

[0207] Each hydraulic drive unit is equipped with an independent hydraulic pump station 3, whose main components and parameters are as follows:

[0208] Main pump: Internal gear pump, rated pressure 31.5MPa, flow rate 44L / min.

[0209] Multiple variable frequency motors: single motor power 22kW, 4 poles, B5 flange mounting, insulation class F.

[0210] Proportional flow valve: Input a variable control signal to adjust the corresponding opening degree and regulate the lifting and lowering speed of the hydraulic cylinder.

[0211] Proportional relief valve: Pilot-operated proportional relief valve, input with variable control signal, adjusts corresponding pressure from 0 to 35 MPa, used for stepless adjustment of system pressure, the combination of proportional flow valve and proportional relief valve realizes soft start and soft stop.

[0212] Hydraulic lock: A hydraulically controlled check valve installed in the rodless chamber port of the hydraulic cylinder to ensure reliable locking of the hydraulic cylinder when it stops.

[0213] Directional control valve: Three-position four-way solenoid directional control valve, with F-type function in the middle position, used to control the extension and retraction direction of the hydraulic cylinder.

[0214] Oil filter: High-pressure pipeline oil filter, filtration accuracy 5μm, with blockage indicator.

[0215] Fuel tank: 3700L capacity, equipped with air filter, level gauge and thermometer.

[0216] Piping: High-pressure hose + seamless steel pipe, pressure resistant to 35MPa.

[0217] VII. Control System Configuration

[0218] The control system adopts a distributed control structure of PLC + host computer:

[0219] PLC master station: Located in the central control room, it is responsible for synchronous control algorithms, data processing, and human-machine interaction.

[0220] PLC slave station: Each computer room is equipped with a remote slave station to collect signals from various sensors and control the hydraulic pump station and brakes.

[0221] Sensors: Each heavy-duty hydraulic cylinder has a built-in magnetostrictive sensor 19 to detect displacement; the hydraulic pump station is equipped with pressure and temperature sensors.

[0222] Actuators: The proportional relief valve is controlled by the PLC via an analog module; the brake assembly is controlled by a digital output.

[0223] Communication network: PROFINET industrial Ethernet, enabling high-speed data exchange between the master station and slave stations.

[0224] Human-machine interface: Touch screen, which displays system status, lifting height, working pressure, synchronization error, etc., and can record historical data.

[0225] The synchronization control strategy employs master-slave fuzzy PID control: the displacement of one set of hydraulic cylinders (master cylinder) is taken as the target value, and the remaining hydraulic cylinders (slave cylinders) follow the displacement of the master cylinder. Speed ​​synchronization is achieved by adjusting the opening of the proportional flow valve of each cylinder (i.e., adjusting the flow rate entering the hydraulic cylinder). The control cycle is 20ms, and the synchronous dynamic error along the bridge is ≤±40mm (for a 102m length of the bridge) and the error along the transverse bridge is ≤±20mm (for a 40m length of the bridge).

[0226] VIII. Detailed Explanation of the Work Process

[0227] 1. Lifting / lowering process

[0228] Once the control system receives a lifting command (such as a manually input target height or a traffic dispatch command), it will automatically execute the following steps:

[0229] Brake release: The control system sends an energizing command to the four sets of brake assemblies 9, the brakes open, and the disc of the nut assembly 10 is released. At this time, the nut assembly is in a free-rotating state.

[0230] Hydraulic system startup: The motor of hydraulic pump station 3 starts, the pressure set by the proportional relief valve gradually increases, and the hydraulic oil enters the rodless chamber (rising) or rod chamber (falling) of heavy-duty hydraulic cylinder 2.

[0231] Micro-motion load: The hydraulic cylinder extends slightly. When the pressure sensor detects that the hydraulic cylinder pressure has reached the rated load, it indicates that the hydraulic cylinder has fully borne the weight of the bridge. At this time, the hydraulic lock maintains the current pressure.

[0232] Brake confirmation: The control system detects the brake open status feedback. After confirming that there is no problem, it continues to rise and fall at the set speed.

[0233] Synchronous lifting: The PLC calculates the displacement error of each cylinder in real time based on the displacement signal fed back by the magnetostrictive sensor 19. The speed is finely adjusted by regulating the opening of its proportional flow valve to synchronize the cylinders. The lifting speed is controlled at approximately 0.312 m / min.

[0234] Guided following: During the lifting process, the roller assembly 30 of the guide mechanism 4 rolls up and down along the guide rail 31 to ensure that the bridge rises and falls vertically without tilting. The expansion and contraction of the bridge caused by temperature changes is automatically compensated by the disc spring assembly 26 to ensure that the rollers always keep in contact with the guide rail.

[0235] Deceleration and positioning: When the bridge is 0.2m away from the target position, the proportional flow valve begins to slowly reduce its opening, and the hydraulic cylinder decelerates; when the target position is reached, the hydraulic pump station stops supplying oil and the hydraulic lock locks.

[0236] Mechanical locking: The control system sends a power-off command to the brake assembly 9, and the brake immediately clamps the disc of the nut assembly 10, achieving mechanical locking. At this time, the bridge is in a safe stopping state.

[0237] 2. Locked State

[0238] When the bridge needs to remain stationary for an extended period, the system automatically switches to load transfer mode:

[0239] Hydraulic cylinder unloading: The control system commands the hydraulic cylinder to retract slightly by about 1-2mm, reducing the hydraulic cylinder pressure to near zero, and the weight of the bridge is gradually transferred to the anti-fall device 5.

[0240] Vertical load transfer path: Support box 6 → Slewing bearing 8 → Threaded nut assembly 10 → Trapezoidal threaded rod 11 → Heavy-duty ball joint bearing 13 → Bridge foundation.

[0241] Self-locking principle: When the lead screw assembly 10 bears a vertical load, due to the large thread helix angle of the trapezoidal lead screw, it tends to slide down along the thread, thereby generating a static rotational torque on the lead screw assembly. The braking reaction torque provided by multiple brakes has a safety factor of approximately 2, which is sufficient to prevent the lead screw from rotating and achieve reliable locking.

[0242] Counter-torque balance: The trapezoidal lead screw generates a counter-rotational torque due to the static rotational torque. This torque is transmitted upward to the guide column 15, and then to the support box 6 through the guide key 7, forming an internal force closed system that does not rely on external energy.

[0243] 3. Start the conversion process

[0244] When the bridge needs to resume raising and lowering from a stationary state, the following steps should be performed:

[0245] Hydraulic load bearing: When the hydraulic pump station is started, the heavy-duty hydraulic cylinder 2 extends slightly. When the pressure sensor detects that the hydraulic cylinder pressure has reached the rated load, it indicates that the hydraulic cylinder has resumed bearing the weight of the bridge.

[0246] Hydraulic lock: The hydraulic lock engages, maintaining the current pressure.

[0247] Brake release: The control system sends an energizing command to the brake assembly 9, the brake opens, and the nut assembly is released.

[0248] Start lifting / lowering: After confirming that the brake is fully open, the hydraulic lock opens, the proportional relief valve pressurizes at the set slope, and normal lifting / lowering begins.

[0249] IX. Maintenance and Repair Methods

[0250] 1. Cylinder liner replacement

[0251] When wear of the guide mechanism cylinder liner 27 leads to excessive clearance, replace it according to the following steps:

[0252] Use the electric hoist 16 of the maintenance crane 1 to lift the balance frame 29 and slightly relieve the pressure on the disc spring assembly 26;

[0253] Remove the cap and lock nut from the end of the guide shaft 28;

[0254] Gently tap the guide shaft 28 with a copper rod to pull it out of the cylinder liner 27;

[0255] Remove the old cylinder liner and clean the guide hole;

[0256] Press in the new cylinder liner and secure it with the set screw;

[0257] Reinstall the guide shaft and adjust the pre-compression of the disc spring assembly to the specified value.

[0258] The entire process takes about 2 hours and does not require disassembling the entire guide mechanism.

[0259] 2. Replacement of heavy-duty hydraulic cylinders

[0260] When a hydraulic cylinder needs major repair or replacement:

[0261] Use a maintenance crane to lift cylinder 20;

[0262] Remove the connecting bolts between the cylinder flange and the support housing 6;

[0263] Remove the connecting pin between the piston rod end ball joint 22 and the ball joint support 23;

[0264] The hydraulic cylinder was lifted out of the machine room and transported to the maintenance area as a whole;

[0265] When installing a new hydraulic cylinder, proceed in the reverse order.

[0266] 3. Maintenance of fall arrestor devices

[0267] Regularly inspect the wear of the trapezoidal lead screw 11 and the lead nut assembly 10, either visually through the observation window or by disassembling the assembly. If severe thread wear is found, the entire lead screw or lead nut must be replaced. When the brake friction pads wear down, the clearance must be adjusted or the friction pads replaced promptly.

[0268] 10. Other Implementation Methods

[0269] Although this embodiment uses four sets of hydraulic drive units as an example, the scope of protection of this invention is not limited thereto. Depending on the bridge tonnage and span, two, six, or more sets of hydraulic drive units can be used, symmetrically arranged at both ends of the bridge. The number of heavy-duty hydraulic cylinders in each unit can also be adjusted to one or two sets depending on the load size. The structural details of the guiding mechanism and fall protection device can also be adapted to the site conditions, and as long as they do not depart from the core concept of this invention, they all fall within the scope of protection of this invention.

Claims

1. A heavy-duty hydraulic cylinder synchronous telescopic drive bridge lifting mechanical system, characterized in that, include: At least four sets of hydraulic drive units, each set of hydraulic drive units including a heavy-duty hydraulic cylinder (2) and a hydraulic pump station (3); Support box (6) is used for fixed connection with the main body of the bridge; A fall arrestor (5) is connected between the support box (6) and the bridge foundation; A control system for controlling the hydraulic pump station (3) and the fall arrestor (5). The cylinder of the heavy-duty hydraulic cylinder (2) is fixedly connected to the support box (6), the hydraulic pump station (3) drives the heavy-duty hydraulic cylinder (2) to extend and retract to drive the support box (6) and the bridge to rise and fall, and the anti-fall device (5) provides mechanical locking when the bridge stops.

2. The system according to claim 1, characterized in that, The fall arrestor (5) includes: The guide sleeve (14) is fixedly connected to the support box (6), and its inner wall is inlaid with a guide key (7). The guide post (15) has a keyway on its outer wall that mates with the guide key (7). The guide post (15) is fixedly connected to the upper end of the trapezoidal screw (11) by high-strength bolts. The lead screw assembly (10) is engaged with the trapezoidal lead screw (11) via a multi-start large helix angle trapezoidal thread; The upper rotating body of the slewing bearing (8) is fastened to the support box (6) by bolts, and the lower rotating body is fixedly connected to the nut assembly (10) by bolts. The brake assembly (9), whose support is fixed on the support housing (6), is used to brake the rotation of the nut assembly (10); The heavy-duty ball joint support (13) is threaded to the lower end of the trapezoidal screw (11) and can be horizontally slidably supported on the embedded plate of the bridge foundation; The anti-hook plate (12) is welded to the embedded plate of the bridge foundation to limit the axial movement of the heavy ball joint support (13).

3. The system according to claim 2, characterized in that, The brake assembly (9) includes multiple brakes that are energized to release the nut assembly (10) when the bridge is raised or lowered, and de-energized to clamp the disc of the nut assembly (10) when the bridge stops, thereby achieving mechanical locking.

4. The system according to claim 1, characterized in that, The heavy-duty hydraulic cylinder (2) includes a cylinder barrel (20), a piston rod (21), a piston (24), and a built-in magnetostrictive sensor (19); the extended end of the piston rod (21) is hinged to a ball joint support (23) via a ball joint (22), and the ball joint support (23) is in horizontal sliding contact with the pre-embedded support of the bridge foundation; the flange end of the cylinder barrel (20) is fastened to the support box (6) by bolts.

5. The system according to claim 4, characterized in that, The piston (24) has a copper-based sintered coating on its surface to improve its pressure resistance and wear resistance.

6. The system according to claim 1, characterized in that, It also includes a guiding mechanism (4), which includes: The guide bracket (25) is fixedly connected to the support box (6); Balanced framework (29); The guide shaft (28) is fixedly connected at one end to the balance frame (29), and the other end is slidably inserted through the guide bracket (25). The disc spring assembly (26) is sleeved on the guide shaft (28) and abuts between the balance frame (29) and the guide bracket (25); Roller assembly (30) is mounted on the balance frame (29); The guide rail (31) is fixed to the wall of the bridge structure and rolls in cooperation with the roller assembly (30); The disc spring assembly (26) is used to accommodate bridge temperature deformation and buffer guiding loads.

7. The system according to claim 1, characterized in that, The hydraulic pump station (3) includes a proportional relief valve for slow, shock-free hydraulic control during bridge lifting and braking.

8. The system according to claim 1, characterized in that, It includes multiple sets of hydraulic drive units, symmetrically arranged in machine rooms at both ends of the bridge. Each set of hydraulic drive units works independently and achieves synchronous lifting control through the control system.

9. The system according to claim 1, characterized in that, It also includes a maintenance crane (1), which includes a rail (18), a trolley (17) and an electric hoist (16); the rail (18) is fixed to the top of the machine room; the trolley (17) is movably suspended on the rail (18); the electric hoist (16) is suspended on the trolley (17) for the installation and maintenance of the equipment.

10. The system according to any one of claims 1 to 9, characterized in that, The support box (6) is fixedly connected to the main body of the bridge by flanges and high-strength bolts. The heavy-duty hydraulic cylinder (2) and the anti-fall device (5) are both bolted to the support box (6) by flanges.

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