Multi-suspension-centres crane

Abstract

The invention discloses a multi-suspension-centres crane which comprises main beams, an operating mechanism, a lifting mechanism and an electric control system, wherein the operating mechanism comprises a bearing mechanism composed of an idle wheel device and an elastic body, and a drive mechanism composed of a motor, a reducer, a winding drum group, two groups of steel ropes, a pulley block and a pulley bracket, wherein the lifting mechanism comprises more than 2 sets of winding machines on each main beam, adopts a multilayer winding and symmetrical rope mode of duplex winding drums and steel ropes, and adopts a mode that a hook connecting piece is respectively hinged or fixedly connected with a corresponding hook group through a pin roll. The multi-suspension-centres crane has the characteristics of safety and reliability, strong practicability and the like through the self-set corresponding control method, is suitable to a crane with ultra-high lifting load, especially the multi-suspension-centres crane for lifting by sections on an offshore drilling platform.

Description

technical field [0001] The invention relates to a crane, in particular to a multi-suspension-point crane suitable for the shipbuilding industry, especially for hoisting when offshore drilling platforms are docked in sections. Background technique [0002] With the introduction of the concept of "segmented docking and overall hoisting of offshore drilling platforms" in China in recent years, it is necessary to have supporting cranes to complete the hoisting of 10,000-ton equipment such as drilling platforms. Compared with traditional cranes, the lifting capacity of this crane has increased by one. The order of magnitude can reach 20,000 tons or more, and the span and lifting height of the crane can reach more than 100 meters. In order to reduce the weight of the upper parts of the main girder, the hoist is usually arranged at the span end of the main girder. In order to ensure that the angle between the multi-layer wound steel wire rope and the drum and the pulley meets the ...

AI Technical Summary

Problems solved by technology

The main disadvantages of this type of crane are: the steel wire rope of the hoisting mechanism is wound from one side of the pulley to the other side, and there is a self-locking phenomenon in the hoisting transmission, which requires an electric booster mechanism; in addition, the transmission efficiency of the hoisting mechanism is low, and the energy There are many losses; specifically, there are the following technical problems:

[0005] 3. The hoisting points of a single set of hoisting mechanisms cannot be lifted synchronously, and electric synchronous mechanisms need to be installed, and high coordination of the electrical system is also required;

[0006] 4. The pulley magnification is too large, the lifting transmission efficiency is low, the energy loss is large, and self-locking is easy to occur;

[0007] 5. The hoisting mechanism and guide pulleys rotate at a certain angle relative to the main girder due to the single-connected drum and the lowering of the rope in the opposite span, so that the requirements for the deflection angle of the wire rope can be guaranteed, which brings great inconvenience to the construction and installation

[0008] At the same time, the type of PTFE plate sliding on the stainless steel plate is usually used on the crane. There is sliding friction between the PTFE plate and the stainless steel plate. The friction coefficient is relatively large, generally not less than 0.15, and the horizontal resistance is large, which increases The power of the driving mechanism generally cannot use the electric drive type, only the hydraulic stepping drive type can be used, resulting in slower running speed and low work efficiency

In addition, in order to reduce the power of the driving mechanism, in order to reduce the layout size, generally only no-load drive is set, if the full-load drive is used, the drive element will be too large

Images