BRPI0707970B1 - MULTIPLE WINCHES - Google Patents

Abstract

multi-winch gantry crane, the present invention providing a multi-winch gantry crane for towing a structural load 1. structural load 1 has two parallel load beams 40a, 40b. the winch system lo includes a fixed belt 12, a parallel belt 16 movable in one direction of the gantry, a plurality of winch units 20 on each belt 12, 16 and a plurality of load connectors 34 engageable on a load beam and another plurality of load connectors 34 engageable on the other load beam. A load distribution is determined and the plurality of load connectors 34 are grouped so that each group has a target load and the center of gravity falls within the selected group of winch units 20 and associated load connectors 34. winch up / down operation, safety checks on winch components, tension / position of each cable 28 and load unbalance l are monitored.

Description

Invention Patent Descriptive Report for “Gantry Crane with Multiple Winches”

Technical Field of the Invention

The present invention relates to a gantry crane with multiple winches for raising and lowering a structural member. In particular, the invention relates to a system and a process for synchronizing a plurality of winches independent of a gantry crane in order to safely raise and lower a suspended load.

State of the art

Marine or offshore structures are usually huge and heavy. Often, a crane with a simple winch is not enough to winch such a marine or offshore structure. As a result, vessels have rested to build modules from such marine structures and then to assemble the modules on a floating dyke. For example, a semi-submersible platform has a hull and a deck. The hulls are composed of two pontoons and a number of vertical columns of each pontoon. Pontoons and vertical columns are typically constructed with steel plates and bulkheads to form a number of internal compartments or ballast tanks. The r platform is also built with plates and screens. Water is pumped into or out of the ballast tanks to adjust the buoyancy of the hull and / or platform during manufacture or the entire semi-submersible platform during operation.

The sizes and weights of such modules in a marine structure or fabricated structure are usually limited by the capacity of the working weight of a crane installation. The pontoon, column or platform partially completed with ballast tanks or usable compartments is often floated in the sea instead of being handled by a land-based crane. For example, a partially completed platform can be floated above a submerged hull; the submerged hull is then floated to raise the partially completed platform above the water level, so that further work on the platform is completed at sea. Such fabrication of structures in the beginning is dependent on weather conditions and available crane barges. This makes the manufacture of such expensive and risky structures.

These marine structures are typically made of steel and require periodic maintenance. Often, after a service life of around 10-20 years, it is more economical to refurbish a marine structure instead of building it again. In order to tow such a marine structure by an overhead crane, the bulkheads must be connected and designed for aerial elevation. Different parts of the structure can have different weights. A crane with multiple independent winches is therefore desired; a crane control process with a plurality of winches for safe operation is therefore required.

summary

The following is a simplified summary to provide a basic understanding of the present invention. This summary is not an extensive overview of the invention and is not intended to identify key aspects of the invention. In addition, some of the concepts of the invention are presented in a generalized form as an introduction to the detailed description that follows.

In one embodiment, the present invention provides a winch system having a plurality of independent winch drum units arranged in each of the two spaced belts. The winch system comprises: a load connector operable to connect to a cable associated with each of the respective winch drum; and a load having two elongated load beams, which are spaced substantially to the same dimension as the spaced belts; wherein the load connector is operable to connect the elongated load beams and the load itself synchronizes the winch operation up and down the independent winch drums.

In another embodiment, the present invention provides a control process for the above winch system. The control process comprises: determining the load distribution with respect to two belts; group winch units and associated cargo connectors into one or more groups so that the center of gravity falls within a group, between two groups or within groups; establish a target load for each of one or more grouping of winch units and associated load connectors; and increasing the load of a predetermined stage such as 10%, up to the target load during the operation while checking the winch system for safety; tension; displacement and speed of each cable; and load imbalance.

Brief Description of Drawings

This invention will be described by means of non-limiting embodiments of the present invention, with reference to the accompanying drawings, in which:

Figure IA illustrates a double belt gantry crane according to an embodiment of the present invention;

Figure IB illustrates the use of load connectors and load bearing beams to winch a load up and down with the crane shown in Figures 1A;

Figure 1C illustrates a load connector shown in Figures IA and lB;

Figure ID illustrates a winch unit shown in Figures IA and IB; and

Figure 1E illustrates an arrangement of the cable pulleys shown in Figures IA and IB.

Figure 2 illustrates a flow chart for safe operation of the crane shown in Figure IA according to another embodiment of the present invention; and

Figures 3A-3E illustrate groupings of winches for synchronizing separate winch units and level control of a load in accordance with yet another embodiment of the present invention.

Detailed Description of the Invention

One or more specific and alternative embodiments of the present invention will now be described with reference to the accompanying drawings. It will be apparent to those skilled in the art, however, that this invention can be practiced without such specific details. Some of the details cannot be described in length so as not to obscure the invention. For reference purposes, the common reference numbers or series of numbers will be used through the figures, when referring to the same or similar aspects common to the figures.

Figure 1A shows a winch system 10 according to an embodiment of the present invention. As shown in Figure IA, the winch system 10 includes a fixed aerial belt 12 and a gantry aerial belt 16 to hold a load L. The fixed aerial belt 12 extends across the top of two columns 13 while the gantry belt 16 extends across the top of two lower columns 17. Although the fixed belt 12 and the gantry belt 16 are at different heights, they are substantially parallel to each other. On each of the belts 12 and 16 there are six winch units 20a, 20b ... 20f. As shown in Figures IA, ID and 1E, each winch unit 20a, 20b ... 20f includes a drum 22, a winch motor-gear assembly 24, a winch brake set 26a, 26b ... etc, an encoder 27, a cable 28 and cable pulleys 30 and a load cell 29. The cable pulleys 30 include a set of fixed pulleys 31 and a set of load connectors 34 connected to a set of displacement pulleys 32 for cooperation with the set of fixed pulleys 31 and a deflection angle pulley 36.

As shown in Figure IA, the fixed pulleys 31a, 31b ... etc. they are connected to a lower edge of each belt 12, 16 in an alternating manner along the longitudinal axis of the respective belt and are evenly spaced. The shifting pulleys 32a, 32b ... etc. and the load connectors 34 are evenly and evenly spaced by the pivoted connection bars 38a, 38b, 38c. In use, the load connectors 34 are connected to an elongated load bearing beam 40 and a load L. As shown in Figures IA and 1B, there are two spaced load bearing beams 40a, 40b. The gantry aerial belt 16 is moved away from the aerial belt 12 to substantially the same dimension between the spaced load bearing beams 40a, 40b.

The winch system 50 also includes a control panel 50 but is not shown in Figure IA. The control panel 50 includes at least one programmable logic controller (PLC) 52, actuator / inverter 54 for each winch motor, an alarm / horn 56, an emergency stop button 58 and a central control console 60. The PLC 52 is programmed to allow manual and automatic control of individual winch unit 20 or groups of winch units. Central control console 60 includes at least one display / touch screen panel 62, control stick 64a, 64b..etc. for each winch unit, indicator lights 66, alarm / horn 56 and emergency stop 58.

With the present invention, the voltage transmitted from each winch unit 20a, 20b ... etc. it is uniformly distributed over the respective sets of fixed pulleys 30 and displacement pulleys 32 to the respective load connectors 34 and load bearing beams 40a, 40b. The load transmitted to different winch units or groups of winches can be dependent on the load center of gravity L.

Operation of the winch system 10 includes performing the following functions:

security checks;

2. pretension and calibration;

3. level control; and

4. synchronized winch group operation;

Figure 2 shows a flow chart 200 for safe operation of the winch system 10, according to another embodiment of the present invention. As shown in Figure 2, operation of the winch system 200 starts from step 205. In step 205, power is supplied to the control panel 50, central control console 60 and headlights / searchlights 70.

A decision is then made in step 210 if the winch assembly is correctly selected considering the weight of the load L and its center of gravity. If the winch assembly is not done correctly and the decision in step 210 is negative, the operation of system 200 is aborted. If the decision in step 210 is positive, the operation of system 200 proceeds to step 15.

In step 215, electrical power is supplied to the winch motor assembly 24 and all other components of the winch system 10.

A decision is then made at step 220 if any safety interlock is activated. A safety interlock includes an on / off button 58 and / or switching system operation to repair / maintenance mode, programming mode or calibration mode. If any safety interlock is activated, system operation is repositioned at step 222. If no safety interlock is activated, system operation proceeds to step 225.

In step 225, each winch / drive motor inverter 54 is checked for normality. If the check in step 225 is negative, that is, a winch motor inverter / driver may be faulty, the system operation is aborted; a signal is then sent to the central control console 60 and the relevant indicator light 66 is illuminated to indicate the fault. If the check in step 225 is positive, system operation proceeds to step 230.

In step 230, a decision is made whether either of the winch motor 24 is overheated. If the decision in step 230 is positive, the relevant indicator light 66 in the central control console 60 is illuminated, as well as a repair indication in step 238. The overheating of the winch motor may be due to malfunctioning of the wind 232, malfunctioning thermistor 234, maintenance period 236 expiry, overload, etc. Once the winch motor failure is rectified, the repair indication is repositioned in step 238. The operation of the system then checks, in step 240, whether the repair / repositioning has been carried out. If repair / repositioning is performed, for example, after a predetermined time interval, the system operation is aborted in step 277. If the repair / repositioning is performed, system operation ips will return to step 230 and the overheat condition the winch motor is rechecked. When all winch motors 24 are in normal operating condition, system operation proceeds to step 245.

In step 245, a decision is made whether each winch encoder 27 is in normal working condition. In normal working condition, the position of each capacitor 27 indicates the cable break part of the respective winch drum 22, which calculates to indicate the vertical position of the load L. At the same time, the rotation per unit time is calculated to indicate the speed of the winch drum 22. If the decision in step 245 is negative, that is, a winch encoder 27 is malfunctioning, system operation stops and runs, in step 295, a failure monitoring program to identify / report the fault condition, for example, by illuminating the relevant indicator light 66. If the decision in step 245 is positive, the system operation proceeds to step 250.

In step 245, a decision is made whether each winch encoder 27 is a normal working condition. In the normal working condition, the position of each encoder 27 indicates the tamper part of the cable from the respective winch drum 22, which is calculated to indicate the vertical position of the load L. At the same time, the rotation per unit time is calculated to indicate the speed of the winch drum 22. If the decision in step 245 is negative, that is, the winch encoder 27 is malfunctioning, system operation stops and executes, in step 295, a fault monitoring program to identify / report the fault condition, for example, by illuminating the relevant indicator light 66. If the decision in step 245 is positive, the system operation proceeds to step 250.

In step 250, each winch brake 26a, 26b ... etc. it is checked if it is under work order. If a winch brake 26a, 26b ... etc. is not under work order, the system operation stops and executes, in step 295, the fault monitoring program to identify the fault / report the fault condition. If all winch brakes 26a, 26b ... etc. are in working condition, system operation proceeds to step 255.

In step 255, each brake pad is checked for normal condition. If any of the brake pad is worn and the associated brake actuator is close to its travel limit, system operation stops and executes, in step 295, the fault monitor / report program. If all brake pads are still in working condition, system operation proceeds to step 257.

In step 257, the speed of each winch drum 22 in the selected winch group made in step 210 is increased by 10%, before the operation of the winch system proceeds to step 260.

In step 260, the speed of each drum is checked for normality. If a drum speed is too fast, there may be a loosening or break in the associated cable 28. In addition or alternatively, the associated winch brake 26 or gear unit 24 may fail. If the speed of the winch drum is too slow, it may be overloaded. If the check in step 260 determines that the winch drum speed is abnormal, the system operation stops and runs the fault monitoring / reporting program in step 295. If the winch speeds of all winch units 24 are abnormal , system operation proceeds to step 270.

In step 270, each load cell 29 associated with a winch unit 24 is checked for overload. If a load cell 29 is overloaded, the condition of the load cell is checked again at step 272 after a predetermined period of time has elapsed. If the check in step 272 is positive again, the system operation stops and executes, in step 295, the fault monitoring / reporting program. If none of the winch unit is overloaded at step 270 or overload condition at step 272 has recovered, the system proceeds to step 275.

In step 275, system 200 allows an operator to operate the winch units 24 up or down according to the operator's command. At the same time, system operation continues to check the system for any security breaches.

In step 280, the dynamic tension and displacement of each cable associated with each winch unit is checked for normality. If the tension and displacement are abnormal, for example, due to looseness or break in a cable, the system operation stops and runs the fault / reporting monitoring program in step 295. If the tension and displacement of all cables normal, system operation proceeds to step 285.

In step 285, the winch units 24 are checked to see if they are synchronized. If the difference in speed of any of the winch units 24 exceeds a predetermined percentage of the difference in speed between all winch units, the system operation stops and runs the fault / reporting monitoring program in step 295. If the differences in the winch speed between all winch units are consistent with the change in the number of cable layers in the winch drum 22, the system operation continues to step 290.

In step 290, any unbalance of the load L is checked again. Load imbalance L may be due to improper selection of the winch assembly. If such an imbalance occurs, and the predetermined percentage difference in the cable stresses and displacements in step 280 is not detected, or the synchronization of the winch units in step 285 is not detected, the system operation stops and executes the monitoring program. failure / reporting in step 295. If no load imbalance L is detected, system 200 proceeds to step 292.

In step 292, system 200 verifies that the entire speed of each selected winch drum 22 has reached its full speed. If the decision in step 272 is negative, system 200 iterates back to step 257 and the winch speed is increased by 10% increases in the entire speed. With each increase in winch speed, the 200 system iterates through step 260 to step 290 and a decision is made again at step 292. If the decision at step 292 is positive, meaning that the relevant winch drum 22 has reached at full speed, system 200 jumps back to node 273 and continues to check each winch unit from step 272 through step 292 for safe operation.

The load L considered in the present invention is typically heavy and expensive; as a result, the center of gravity is typically not in the geometric center. Thus, the lifting of the load L must be planned in such a way that the load's center of gravity is within the envelope defined by the load connectors 34; This is to ensure that the load is not tipped over when lifting or lowering. This problem is complicated by the present invention because all winch-gear assemblies 24 are not mechanically synchronized. The problem found in the present invention is overcome by the benefit of load stiffness L acting as a synchronization mechanism. At the same time, the voltages and speeds of the cables 28 are monitored so that the load L remains level during lifting or lowering.

Figures 3A-3E illustrate various groupings of the winch units 24 for safe operation of the winch system 200 according to the present invention. As shown in Figure 3A, some of the winches on both belts 12, 16 are operated in a group such that the center of gravity falls within the envelope defined by a group of winches. If the cable tension on any winch unit in the group of selected winches exceeds its working load, the winch operation is stopped and the monitoring program would prepare the operator to regroup the winch units for safe operation.

Figure 3A illustrates a grouping of winch units 24 in each of the two belts in addition to a third grouping that links both belts. Figure 3B illustrates a group of winch units 24 on one belt and two other groups on the second belt. Figure 3C illustrates a U-shape of the winches that expands both belts. Figure 3D illustrates a grouping of winch units 24 in each of the two belts 12, 16. Figure 3E illustrates a grouping of winch units 24 on a belt and an L-shape that expands two belts. In these possible winch bundle configurations, the center of gravity falls within a large envelope defined by the winch bundle. During the up and down winch of load L, the associated cable tension and speed in each of the winch unit 24 are continuously monitored. That is, the cable tensions are maintained within the safety workload to ensure safe operation; at the same time, system 200 ensures differences in cable speeds that do not exceed the predetermined percentage speed difference. So that all winch-gear assemblies 24 are substantially synchronized and the load L remains substantially level.

Once all safety checks in steps 210255 are complete and the cable (rope) / cable tensions and displacements, along with percent differences, are within the limits of the drawing, up / down operation of the winch in step 275 continues. During initiation, for example, during initial system installation or after maintenance, the winch operating step 275 includes a requirement and calibration step 277 and a load leveling step 278. In one embodiment, the requirement is made by screeching each set of displacement sheave blocks 32 and load connectors 34 at a slow speed such that the cable looseness is considered. When there is no more loose cable, the reading of each load cell 29 on the central control console 60 associated with each winch unit 20 is zeroed and the position of the read control rod 64 is repositioned. In load leveling step 278, a test load is connected to two or more groups of winch units 20 and the test load is lifted to a predetermined constant speed. During each load leveling test, the position and speed of each winch unit 20 are recorded by a data log connected to PLC 52. The vertical position of the test load and the speed of the winch units are analyzed; for example, the change in height and the corresponding speed, the winch with the very low speed is chosen as the reference winch, whose position and speed are used as reference data for the positions and speeds of all other winch units 20. In in other words, automatic calibration of winch positions and speeds is performed; Manual and automatic compensation is then made possible. In addition, load cells 29 are calibrated. System 200 is also provided for manual and automatic operation of the whole crane.

Once the requirement, calibration and automatic leveling of the winch system is fulfilled, winch system 10 is ready for use. As shown in Figure 2, the winch system 10 continues to monitor the tension and displacement on all cables 28 in step 280. In addition, the winch system 10 also continues to monitor the load level control L by checking the synchronization of all winch units 20 in step 285 and checking for any imbalance in step 290.

In the implementation of the group winch according to the present invention, the mass and center of gravity of different modules composing the load L are determined. A load distribution is determined and a selection of 5 winch groups is then made with each group having a target load. During an up-down operation of the winch, the target load is increased by a 10% increase over a predetermined period of time. During each load increment, all safety checks in step 220 through 10 in step 272, tension / displacement in step 280 and load imbalance in step 285 and 290 are performed. If any imbalance in the load occurs, the winch group (s) is / are re-defined and the operation of system 200 is performed again.

Although specific embodiments have been described and illustrated, it is understood that many changes, modifications, variations and combinations thereof can be made in the present invention without departing from the scope of the invention. For example, a gantry crane with multiple winches on more than two belts can be used.

Claims (7)

1. "Gantry Crane with Multiple Winches" characterized by being a winch system having a plurality of independent winch drum units arranged in each of the two spaced belts, the system comprising: an operable load connector for connecting to a cable associated with each of the respective winch drum; and a load having two elongated load beams, which are spaced to substantially the same dimension as the spaced belts 10; wherein the load connector is operable to connect with the elongated load beams and the load itself synchronizes the up / down squeaking operation of the independent winch drums. 15 2. "Multi Winch Gantry Crane" according to Claim 1, characterized in that the load connector is connected to a shifting pulley block while a fixed pulley block is arranged on the relevant belt. 3. "Gantry Crane with Multiple Winches" according to Claim 1 or 2, characterized where the process comprises: determine the load distribution with respect to two belts; group the winch units and associated cargo connectors into one or more groups, so that the center of gravity falls within a group, between two groups or within groups; establish a target load for each of one or more groupings of winch units and associated load connectors; and increasing the load by a predetermined step until reaching the target load during operation while checking the winch system for safety; tension, displacement and speed of each cable; and load imbalance. 4. "Gantry Crane with Multiple Winches" according to Claim 3, characterized in that the predetermined 35 stage is 10% of the target load. 5. "Gantry Crane with Multiple Winches", according to Claim 3 or 4, characterized in that the imbalance in the load occurs when the percentage change in the tension, displacement or speed of a unit of 5 winch exceeds a predetermined percentage change. 6. "Gantry Crane with Multiple Winches" according to any one of Claims 3-5, further comprising: requirement of each cable and calibration of the load cell associated with it 10; and load leveling. 7. "Gantry Crane with Multiple Winches" according to Claim 6, characterized in that after carrying out load leveling, the lowest speed winch is used as a reference winch for other winches 15 regarding displacement or speed.