RU2442743C2 - Double-girder crane with number of supports - Google Patents

Abstract

FIELD: double-girder crane.

SUBSTANCE: invention refers to a double-girder crane with a number of supports. The crane contains main girders, a lifting mechanism, a traveling gear and an electric control system. The main girders are represented by the upper and the lower girder. Each of them has different sections and is a high narrow built-up girder that is formed by three box girders, and the lifting mechanism contains a number of lift units. Each of these units is connected to a number of supports that are put simultaneously in motion with the help of the electric control system. The device for cable arrangement is installed on the lift units. This device contains an integrated connection multi-layer rerolling system. The traveling gear of the main gird is represented by a bidirectional self-moving mechanism that is situated at both ends of the base plate of the lower main girder.

EFFECT: augmentation of the crane capacity.

5 cl, 16 dwg

Description

FIELD OF THE INVENTION

The invention relates to hoisting mechanisms, in particular, to double-girder cranes with a plurality of suspension points, intended for coupling with the load along its entire length and for the construction of offshore platforms.

State of the art

Along with the growth of requirements for offshore platforms, their construction requires large cranes for lifting and installing large blocks. At the same time, there is a need to adapt cranes to vertical supports of various heights and offshore platforms of different widths, so that a significant part of the work at height can be replaced by work on the ground, and structures can be lifted and mounted at the same time. This will save time during the construction of offshore platforms, reduce costs, ensure staff safety and improve the quality of work.

However, such cranes must have an extra-large lifting capacity (the total lifting load can reach 20,000 tons), an extra-large lifting height (up to 103 m) and an extra-large span (125 m), which entails significant difficulties in the design, manufacture, installation and commissioning . For example, you need to choose the design of the main beam, the type of lifting mechanism, decide how to position the mechanism with many lifting points, solve the problem of stress concentration when starting and opening the outlet / inlet for steel hummocks in the main beam, decide how to set the main beam in motion, as well as how to balance and synchronize the load with many suspension points. There is no such crane in the world yet.

Disclosure of invention

In view of the aforementioned limitations in existing technologies and the virtually immediate needs of the industry, it is an object of the invention to provide an ultra-large lifting crane that meets the requirements of new technological processes for manufacturing offshore platforms.

This problem is solved in a two-frame crane with many suspension points containing the main beams, a lifting mechanism, a moving mechanism, an electric control system, a rotary servicing crane, a crane operator’s cabin, an anchor device and windproof mooring cables, the main beams being the upper and lower main beams installed respectively on the upper and lower concrete bases, while the two main beams are not connected at the ends, and each main beam is fixed with anchor device and windproof mooring cables, ensuring the stability of both beams in working or non-working condition. Each main beam has different sections and is a high narrow composite beam formed by the upper, middle and lower box-shaped beams. The ratio of the height and width of the high narrow composite beam is 3-5.

The lifting mechanism comprises a plurality of lifting devices located at two ends of two main beams. At each end of each main beam are one or more lifting devices. Each lifting device has one or more suspension points, driven synchronously by an electric control system. The lifting device comprises a cable placement device and a single multi-layer connecting rewinding system, which excludes cable tangling when climbing to full height and prevents contact between the lifting steel cables and also between the steel cables and the main beam.

For example, in a bridge hook crane with characteristics of 20,000 tons × 125 m, the lifting mechanism contains 12 lifting devices, with three lifting devices at each end of each main beam, each of which has four suspension points. Thus, the crane as a whole has 48 suspension points.

The movement mechanism is a bi-directional self-propelled mechanism mounted perpendicular to the axis of the main beam at the base of the lower main beam at its two ends.

The electrical control device is designed for a statically indeterminate crane system with many suspension points and contains a drive device based on a converter, inverter, remote data transmission module, motor, controller, load sensor, position sensor and host computer.

The controller is responsible for communication with the host computer, receives control commands, provides the reverse transmission of information, simultaneously controls the lifting mechanisms and receives feedback signals from the sensors.

The load sensor and the position sensor send information about the load and the lifting height of each lifting mechanism to the controller through the remote data transmission module contained therein, while the operation of each lifting mechanism is controlled after the controller processes such information.

The controller, sensors and lifting device are connected via a remote data bus.

The controller is a programmable logic controller, the load sensor is a weight sensor, and the position sensor is a code sensor.

The electrical control system for a statically indefinite system of cranes with many suspension points contains a control system that automatically calculates the center of gravity of the load and distributes the necessary tensile force for each suspension point, a balance control system that prevents tipping over, a linear speed synchronization control system for each device and an automatic system control the horizontal position of the goods. The electrical control system provides synchronization of crane load, stable lifting of objects, independent and coordinated movement of 12 lifting devices, as well as horizontal movement of the main beam.

Compared to existing technologies, the invention has obvious advantages:

- the crane according to the invention can raise and lower an extra-large load;

- the lifting mechanism contains many lifting devices, which is especially convenient for production, installation and maintenance, and also reduces costs;

- the design with the upper and lower main beams is suitable for lifting and coupling large blocks of offshore platforms with high supports and avoids the technical difficulties and low reliability characteristic of structures with one main beam;

- in general, the machine is characterized by safety, reliability and can adapt to changing distances between suspension points;

- high narrow composite beams formed by three box-shaped beams, have a suitable design, high permissible load and low dead weight, and can also effectively solve the problem of starting and opening the outlet / inlet for steel hummocks on the main beam;

- a special design will help reduce the cost of the foundation;

- the crane according to the invention will significantly improve the manufacturing efficiency of offshore platforms.

As a result, the invention has not only obvious economic benefits, but also contributes to a change in the method of manufacturing offshore platforms, has huge social benefits and has a significant impact on the manufacture of offshore platforms in China and the rest of the world.

Brief Description of the Drawings

Figure 1 (left, middle and right parts) shows the construction of a crane according to the invention, a General view;

figure 2 (left and right parts) - crane, shown in figure 1, side view;

figure 3 - design of the main beams according to the invention;

figure 4 is a section along aa in figure 3;

figure 5 - diagram of the rewinding of a steel cable in one lifting device of the lifting mechanism according to the invention;

figure 6 (left, middle and right parts) - the lifting mechanism of one main beam, shown in figure 1, a top view;

figure 7 - movement mechanism, General view;

on Fig - automatic calculation of the position of the center of gravity of the cargo;

figure 9 - automatic distribution of the tension force at each point of the suspension;

figure 10 is a block diagram for synchronizing the control of the lifting device;

11 is a block diagram of a lifting device.

List of reference numbers in the drawings:

1 - Upper main beam

2 - Lower main beam

3 - Lifting device

4 - Movement mechanism

21 - Articulated support

22 - Hydraulic movement mechanism

23 - cylinder support column

24 - Stainless steel slide rail

25 - Square guide rail

26 - Modified Polytetrafluoroethylene Plates

31 - Controller

32 - Control system

33 - Load Sensor

34 - Position Sensor

35 - host computer

The implementation of the invention

The invention is described in detail below using an example of a hook bridge crane with characteristics of 20,000 tons × 125 m.

As shown in FIG. 1, the upper main beam 1 and the lower main beam 2 are mounted on two concrete bases of different heights. The lifting mechanism contains 12 lifting devices (six lifting devices 3 on each main beam). Each lifting device 3 comprises a winch, a steel cable, a guide block, fixed and movable blocks. The coefficient of increase in force in such a device is 40. Each lifting device contains four movable units, each of which controls one suspension point. The winch contains a winding drum (including a steel cable clamp), a gearbox, a brake, a clutch, a movable shaft, a base and other parts, that is, a complete mechanism from the clutch connected to the engine to the final brake stage. The lifting device is connected to the device for placing the cables and contains a single multilayer rewinding system, which ensures that the cables are not mixed up during lifting to full height. As shown in figure 3, the winch performs each cycle of ascent and descent using the winding drum drive. Each lifting device controls four suspension points. 12 lifting devices have a total of 48 suspension points for simultaneously lifting and lowering the load of 20,000 tons. Figure 5 shows the winding of a steel cable in a lifting device.

Figure 3 shows the main beam with different sections, and figure 4 shows the composite tall narrow beams formed by three box-shaped beams (upper, middle and lower). These composite beams have a height to width ratio of 4.

Figure 6 shows the placement of steel lifting cables in a crane with a plurality of suspension points, preventing the mutual influence of steel cables. As shown in figure 1, the winch is located on the upper part of the main beam. At each end of the beam are three winches. The steel cable of each winch passes through a fixed guide block above the upper part of the main beam and through a small hole in the upper part of the main beam enters the fixed block located inside the main beam, repeating the winding many times, and then attaches to the point located on the fixed block.

Three winches are rigidly mounted above each main beam at different heights, so that the winding drums of different winches have different rope heights. In addition, between the line connecting the "vertical middle line of the winding reels of three winches at each end of the main beam and the middle line of the guide block", and the middle line of the main beam there is a small angle of inclination of the cables. In order to ensure that the angle of inclination of the cables on the winding drum and the block does not exceed the standard value, three winches at each end are rotated 1.04 ° against the midline of the main beam in the opposite direction from the angle of inclination at both ends. This is an alternating arrangement of the steel cable in space, which avoids the mutual influences between the steel cables and the main beams, and also ensures that the angle of inclination between the steel cable, the winding drum of the winch and the unit corresponds to the standard value.

The connecting rails between the movable blocks maintain a predetermined distance between the four movable blocks, each of which is controlled by a lifting device, which provides simultaneous lifting and lowering of the four suspension points controlled by the four movable blocks, and avoids the mutual influence of steel cables.

7 shows a bi-directional self-propelled mechanism of the main beam of a crane. The main beam 2, located on the lower base, can move bi-directionally relative to the vertical axis of the main beam to adapt to different positions of the suspension points on different equipment. The movement mechanism includes a hinge support 21, bearing the weight of the main beam 2 and the weight of the load, a hydraulic movement mechanism 22, a support column 23 of the cylinder, a sliding guide 24 made of stainless steel, a square steel rail 25, modified polytetrafluoroethylene plates 26 and a self-locking wedge clamping mechanism.

For example, to ensure movement of ± 7 m, it is practically impossible to create a hydraulic cylinder that is extendable or retractable by 14 m, therefore, a stepwise hydraulic movement mechanism is required. The hydraulic movement mechanism 22 comprises a hydraulic system, an electrical system, and a support post. The hydraulic system contains two lifting cylinders. The hydraulic movement mechanism 22 can raise the main beam in two directions along one square steel rail and push it 0.8 m for each step. At each step, a pair of self-locking wedge clamping devices fixes a square steel rail 25. Another pair of wedge clamps is not in working condition. Then the piston rod extends the support post 23 of the cylinder and drives the main beam. When it moves 0.8 m, a self-locking wedge clamping mechanism opens rail 25, and the hydraulic pump pumps oil in the opposite direction so that the support column moves 0.8 m in the same direction; a self-locking wedge clamping mechanism fixes a square steel rail 25; the piston rod again pushes the supporting post 23 of the cylinder, driving the main beam 2 in motion. The cycles mentioned above are repeated until movement to the required distance occurs. During the reverse movement, another pair of wedges begins to work, and the reverse movement is carried out in the aforementioned manner.

Then, the main beam moves relative to the base during construction work, laying plates with an attached layer of a mirror-clean stainless steel sliding guide 24. A layer of modified polytetrafluoroethylene in the form of plates 26 is located on the upper part of the base below the hinge supporting the main beam. Thus, the coefficient of friction is significantly reduced, and the material has a slight deformation of compression and a low coefficient of wear.

A crane with many suspension points provides a synchronized and stable lifting of the load using an electric control system. The electric control system automatically calculates the center of gravity of the load, distributes the tension force at each lifting point, controls the balance, preventing the load from tipping over, synchronizes linear speed control for each mechanism, automatically controls the horizontal position of the loads and performs the various control tasks mentioned above.

The lifting mechanism system contains 12 lifting devices, which are controlled according to the following plan:

1. The center of gravity of the loads is automatically calculated (Fig. 8) and the tension forces are distributed at each suspension point (Fig. 9).

In the “Hang Mode”, tension sensors at 12 suspension points measure the load tension force in a horizontal position. Figure 9 shows the actual measurement of the tension force. The control system automatically calculates the position of the center of gravity of the goods, based on actual measurements, and automatically distributes the specified tension force at the suspension points in accordance with the arithmetic sequence. Figure 9 shows the distribution of the tension force. Such a device provides a reasonable distribution of the tension force at all points of the suspension during the lifting process and effectively prevents tipping.

2. The balance of many lifting devices is ensured by an anti-tipping device.

The control system analyzes and appropriately distributes the load for twelve lifting devices, automatically calculating the position of the center of gravity of the load and distributing the tension force for each lifting mechanism. Controlling the tension force at each point of the suspension during operations is considered as another important control task. The control system determines the tension force so that in the process of performing work, each hook is a control object. As soon as the tension force at the suspension point exceeds the set value, the mechanism will adjust it so that the tension force returns to the allowable value, thereby effectively preventing tipping.

3. Synchronously controlled speed 12 of the lifting devices (figure 10).

The lifting electric motor controls the speed as a setting and synchronizing speed device and as the main control device in the process of combined lifting. Since the lifting mechanism carries out multi-layer winding of the steel cable, the linear speed of the various layers of the lifting mechanism is different from the speed of the lifting electric motor. The control system sets a different speed in accordance with the frequency signal of the converters, calculated for different layers, and checks to ensure consistency of the linear speed of the steel cable in each lifting mechanism.

4. Weights are steered horizontally.

To control loads in the horizontal plane, an additional control device is introduced, which determines in real time the relative position of the various suspension points during the lifting process. If the generated coordinate plan of the lifting points does not correspond to what is stored in the memory in the hovering mode and exceeds the specified values, then the position is adjusted so that the load during the lifting generally remains in the horizontal plane.

The industrial control computer implements various mathematical control procedures in accordance with the electric control plan and implements the synchronization and stable operation of lifting devices using a large amount of complex calculations and logical control.

At different stages of the general lifting, various control devices are involved, which are divided according to the “preparation method, the method of pre-tensioning, the method of hovering and the method of general lifting”. With various control methods, the control system uses various control devices and automatically collects data, performs calculations, makes a decision and reviews the data, achieving a high degree of automation.

To achieve the goals set above, the system uses the following advanced technologies:

- reversible AC electric motor, adjustable drive, frequency regulation and speed control system, which allows you to precisely control the speed and moment of each electric motor;

- parallel operation of many corrective devices and feedback devices to control high power engines and achieve energy-saving effect;

- a powerful industrial control computer that works perfectly both with the main control system combined with industrial local area networks and with a set of bus bus connection technologies for implementing "centralized distribution" control for stable and fast data collection and calculation.

The preferred embodiment of the invention is described above. Any equivalent replacement or modification within the scope of the technical capabilities shown in accordance with this invention may be made by a person skilled in the art based on technical planning or the concept of the present invention.

Claims (5)

1. A two-girder crane with many suspension points, containing the main beams, a lifting mechanism, a moving mechanism, an electric control system, a rotary servicing crane, a crane operator’s cabin, an anchor device and windproof mooring cables, with the main beams representing the upper and lower main beams (1, 2), installed respectively on the upper and lower concrete bases, are not connected at the ends, and each of them is fixed with the help of an anchor device and windproof mooring cable s, each of the main beams containing different sections and represents a high narrow composite beam formed by three box-shaped beams; wherein the lifting mechanism comprises a plurality of lifting devices (3) located respectively at the two ends of the two main beams, with one or more lifting devices installed at each end of each main beam, each of which has one or more suspension points, synchronously driven with using an electrical control system; while the lifting device is connected to the cable placement device and contains a single connecting multilayer winding system, and the movement mechanism is a bi-directional self-moving mechanism (4) mounted perpendicular to the main axis of the beam at the base of the lower main beam (2) at its two ends. 2. The crane according to claim 1, in which the ratio of the height and width of the high narrow composite beams is 3-5. 3. The crane according to claim 1, in which the lifting mechanism contains 12 lifting devices, and at each end of each main beam three lifting devices are installed, each of which has 4 suspension points, and the whole machine, therefore, has a total of 48 points suspension. 4. A crane according to any one of claims 1 to 3, in which the electrical control device is designed for a statically indefinite crane system with a plurality of suspension points and comprises a registration system (32) based on a converter, inverter, remote data transmission module, motor, controller (31), a load sensor (33), a position sensor (34) and a host computer (35), wherein the controller is configured to communicate with the host computer, receive a control command, transmit information back, simultaneously control Aviation lifting devices and receiving feedback signals from sensors; the load sensor and the position sensor are configured to transmit information about the load and the lifting height of each lifting mechanism to the controller through the remote data transmission module contained therein, the operation of each lifting mechanism being adjustable after the controller processes the information; wherein the controller, sensors and the lifting device are connected via a remote data bus. 5. The crane according to claim 4, in which the controller is a programmable logic controller, the load sensor is a weight sensor, and the position sensor is a code sensor.

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