What is an asynchronous jacking system?

Synchronous jacking system is a special testing instrument used in the field of mechanics. It is mainly used to precisely control multiple hydraulic jacks at the same time to realize the movement, lifting and positioning of large or heavy structures. Compared with traditional artificial jacking, it has the advantages of high precision and high controllability and is mainly used in bridge bearing replacement and old bridge reconstruction projects that require high construction accuracy.

Introduction to Synchronous Jacking System

The synchronous hydraulic jacking system is divided into 5 parts: hydraulic pump station, PLC computer control system, hydraulic system, displacement pressure detection and man-machine interface operating system. The system integrates hydraulic jacking system, computer PLC signal processing, displacement monitoring with bridge structure analysis and construction technology, and develops a complete set of technologies on the integrated system. Its core is: on the basis of bridge structure analysis and construction technology summary, design computer PLC signal processing and hydraulic system according to bridge characteristics, input displacement signal of external monitoring facilities, output hydraulic system oil quantity control signal, and use multiple sets of jacks at the terminal to achieve the purpose of lifting bridges in a balanced, safe and efficient manner. Its jacking and landing accuracy error does not exceed ±0.5mm, the jacking load includes: 50 tons – 1000 tons, and the jacking height is 10mm to 500mm.

How does the synchronous jacking system work?

The principle of synchronous jacking is to collect data from the displacement sensor or pressure sensor to the PLC control equipment and set the PLC computer through the man-machine operation interface, so that the PLC computer can automatically control the electric hydraulic pump station and the jack. Finally, the lifting, lowering and positioning of various large and heavy objects can be realized. It is suitable for heavy objects with uneven weight distribution.

In the synchronous jacking system, the hydraulic pump station uses the on-off valve to control the flow, that is, by adjusting the switching frequency of the on-off valve to change the flow, so as to achieve the purpose of continuously adjusting the output flow of the oil pump. With appropriate electronic control and detection feedback system, the closed-loop control of pressure and displacement can be formed, and the load balance of each jack can be precisely controlled during the synchronous weighing process when lifting and lowering.

Since the ground of the workpiece is not necessarily flat, in order to ensure the consistent load of the multi-tops, before lifting the workpiece synchronously, first let the multi-tops evenly contact the workpiece, and take the point that the multi-tops evenly contact the workpiece as the benchmark for the synchronous operation of the multi-tops. For this purpose, there is a fitting function in the system. Activate this function before synchronizing lifting, and multiple tops will rise at the same time. Once there is a top contacting the workpiece, the top will stop rising until all the tops touch the workpiece. Then the multi-top evenly rises to about 5Mpa per top (the fit pressure value can be set on the industrial computer), at this time the multi-top automatically stops, and the position of this point is used as the synchronization zero point.

What is the difference between a synchronous jacking system and a diverter pump?

The diverter pump is a multi-point lifting solution for structures with uneven load distribution. The pump provides a nominally equal flow of oil to each outlet to lift the load, which provides enough equal lift for many applications. However, if the load distribution is uneven, or the required cylinder strokes are different, small changes in the lift are amplified and in some cases may result in an uneven lift. Therefore, if a higher precision synchronous lifting is required, the synchronous lifting system is a more suitable choice.

How to use the synchronized jacking system?

1. Check and install equipment such as jacks, displacement sensors and pressure sensors. It is necessary for the jack device to ensure that the ground is flat, and the displacement sensor device to ensure that the cable is straight.
2. Hydraulic hose. According to the distribution of the jacks, connect each jack and the oil outlet of the electric hydraulic pump station with hydraulic hoses.
3. Connect the power cable. Connect the main power plug to the pump station, and then connect the jack displacement sensor and the pressure detection port on the hydraulic pump station with signal cables according to the distribution of the jacks.
4. Before the jack is lifted synchronously, first check whether the reading of the displacement sensor is normal, pull out the displacement sensor cable, and check whether the reading on the display screen is the same as the displacement reading pulled out by the on-site cable.
5. After the button operation of the fitting function is performed before the synchronous lifting, the jack is lifted. When the pressure reaches the fitting pressure value, the jack will automatically stop lifting. The setting value of the fitting pressure is: the optimal setting value is about 50% of the actual load.
6. After the fitting is completed, first set the maximum stroke of the jack (displacement of the heavy object), press the synchronous up button, then the jack will automatically rise, and automatically stop rising when it rises to the set stroke (displacement).
7. The jack is lowered synchronously. After the fitting is completed, first set the stroke of the jack (displacement of the heavy object), press the synchronous lowering button, the jack will automatically lower, and automatically stop falling when it reduces to the set stroke (displacement).
8. Single action operation: Set the label of the jack to be controlled. Press the separate jacking, separate descending buttons. To abort press the stop button.
9. The displacement synchronization accuracy of the jack, the pressure (load) synchronization accuracy, the maximum displacement of the jack, the minimum displacement, the maximum pressure and the minimum pressure can be set.
10. When the synchronization error exceeds the set requirements, the control system will actively alarm to ensure the safety of lifting heavy objects and the lifting system itself.

What are the features and advantages of the synchronous jacking system?


1. Mainly based on displacement control, supplemented by pressure parameter control;
2. Multi-point synchronous displacement error ≤±05mm;
3. Use the pull-wire sensor to monitor the displacement change, and automatically feed back to the control system for action adjustment. The resolution of the pull-wire displacement sensor: 0.004mm, which fully meets the highest precision requirements of civil engineering;
4. The displacement sensor and the jack are installed separately, which avoids the misjudgment of the displacement caused by the displacement of the jack foundation during the lifting operation;
5. Automatic alarm and stop when the error exceeds the limit;
6. The working pressure and displacement of each operating point can be individually set, operated and monitored;
7. It can support single-acting jack or double-acting jack;
8. It can be expanded to 128, 256 or even infinite through the field bus;
9. During the beam dropping process, the system can maintain the same control accuracy as the jacking process;
10. The electric control system and the hydraulic system are adopted in a split structure, which is convenient for on-site installation and handling.


High-speed zero setting, low-speed jacking, and lifting speed can be controlled arbitrarily.
The external (or built-in) displacement, pressure sensor, and load-balancing valve of the hydraulic jack ensure the high reliability of the jacking system in the harsh working environment.
The overload protection function of the load-balancing valve avoids the common cylinder expansion accident during multi-cylinder jacking.
The advanced oil inlet speed regulation and heavy-duty pioneer hydraulic circuit can not only achieve high-precision synchronization when jacking up, but also ensure high-precision synchronization when descending with the load.
The operation is simple and intuitive, and the adjustment of the roll and pitch of the work can be realized.
It can be connected to a color touch screen to display the lifting displacement and lifting load online in real-time, and it can also be connected to an industrial computer to record the entire construction process in real-time.
It can be extended to multi-point synchronization of 32 points or more. In the multi-point synchronization working state, in addition to maintaining the synchronization of multi-point positions, the load distribution of each fulcrum can be adjusted according to the user’s requirements.

Application and main functions of synchronous jacking system


The synchronous jacking system consists of two parts, the real-time monitoring system and the hydraulic power system, which can realize centralized operation and decentralized monitoring of the actuator. The synchronous jacking system can collect the displacement and pressure data information of each part of the building in real time through the sensor, and compare the information with the set safety threshold, and change the working power frequency of the motor to control the oil supply rate, so as to accurately control the synchronous jacking of the jack under different loads, and ensure that the jacking error is within 0.5mm.

Main application

1. Suitable for simultaneous jacking and load positioning applications
2. Synchronous lifting for weighing and moving large and heavy objects
3. Lifting and lowering of heavy equipment during installation and maintenance
4. Highway bridge maintenance, reinforcement, jacking and replacement of rubber bearings
5. The overall elevation of expressways and railway overpasses
6. Lifting and translation of buildings
7. Weight weighing, pile foundation structure test
8. Support and push
9. Leveling of existing buildings
10. Bridge jacking and repositioning
11. Horizontal load movement
12. Synchronized pressurization
13. Hull jacking
14. Bridge raised

What is the price of the synchronized jacking system?

The price of a synchronous jacking system is generally around several thousand dollars. If you need a complete set of systems, including jacks and other parts, the price is generally around $10,000. The whole system will be shipped after adjustment and testing by engineers. Operators can use it directly without additional commissioning. In terms of accessories and after-sales, torcstark will provide a one-year warranty, and provide some accessories for free.

Where to buy or lease a Synchronized Jacking System?

The main synchronized jacking systems currently on the market are from Enerpac and TorcStark. Among them, Enerpac’s EVO series synchronous jacking system has been designed for different application conditions, and it is very worth buying or leasing. You can also opt for TorcStark’s synchronized jacking system. TorcStark mainly has RMCD, PMC, FMCS, 3DCS and other series for different working conditions. Moreover, the TorcStark synchronous jacking system is cheap, widely used and highly targeted, and is very worth buying or leasing.