Große Turmdrehkrane

16. Oktober 2009

mq-2000

16. Oktober 2009

DBQ3000 Type Tower Crane

This crane is the mainly used for installation of 200-600MW per unit capacity thermal electric power generating sets. It can also be used in petroleum, chemical, and metallurgical engineering projects for construction and installation operations.

Two basic combinations, tower type and mast type, are available. Each combination can be composed for various dimensions of height and radius, thus forming dozens of hoist characteristics to meet the needs of different engineering arrangements. The machine is consisted of more than 40 parts. The upper construction includes the mast, jib, main brace, auxiliary brace, various supporting bars and pulley sets, holding-up frame, rope winding system, platform, control cabinet, electrical cabinet and replaceable masthead. The lower construction includes the gantry, slewing ring, traversing bogie and balance girder. The electric cable winder and central electricity transmission installations are also included.

The grabbing device is the hook. Three hooks of different tonnage are equipped. Auxiliary hook is provided for type 2. The drive system includes traveling mechanism, slewing drive mechanism, main/auxilary hoisting mechanisms and main/auxiliary derricking (holding-up) mechanism. There are lots of safety protection installations: lifting height limiter, track clampers, jib derrick detecting and limiting installation, jib dip limiter, pulling force detector of the hoisting rope and derricking rope, electronic moment limiter, and overloading short circuit, power failure protections as well. In addition, the electrical system and balance weight are included.

In the upper construction, the main parts that bear pressure are of pipe truss structure. After manufacture, the sections of the mast and jib are linked by pin shafts and all have exchangeability for installation. The parts that bear pulling forces are steel cable sets with aluminum alloy die connectors. Such a construction features clear distribution of forces, lightweight, low wind resistance and conveniences for installation. The lower construction is a rectangular plate beam gantry with good rigidity and tensional strength. Four sets of double track traveling mechanism are equipped on the four legs respectively under the gantry and is driven by a motor separately. The slewing ring installation with 11m ball bearing sleeve wheel is used for the bottom slewing mechanism, which simultaneously contact the two upper are tracks and the bottom circular tracks and support the upper slewing part. The components are all split type linked by refined bolts with reamed holes for transportation conveniences.

The lifting mechanism of type 1 is driven by two motors, a bid one and a small one, connected on the double extending shafts respectively. At heavy load, the two drive simultaneously. At light load or idle condition, however, the small drive singly. Switching from 8-pole to 4-pole status, the motor operates with double speed. Two hoist mechanisms are equipped for type2, all driven by single motor. When the hoisted weight is less than or equal to 10t, the minor hoist mechanism is used, thus raising the lifting speed to 20m/min. when the hoist weight is less than 60% of the normal data of the main hook, combing operation of two hooks is obtainable, which can increase the hoist efficiency and expand the operation area. Auxiliary hook of 15t(including the tackle weight) can also be added to the type 1, with 20m/min lifting speed. Eddy current speed regulation is adopted for both crane types? hoist mechanism, featuring smooth start and stop and capability of realizing low speed when the hoisted weight is in position.

In order to prevent the jib from surpassing the limited position and absorb pulse energy, the jib of type 1 is position-limited by brace of butterfly spring type. For type1, the braces of both mast and main brace are hydraulic type. Type2, however, is modified to use simple butterfly spring mechanism.

The type1 has manual track clampers, while a set of electric track clampers is added to type2 for operation conveniences. All control operations are made in the control cabinet. The assemblage in site is started with assembling the components on ground, then held the whole body upright. Compared with other large-scale tower cranes, the ?holding-up? mode earns significant advantages in assembling and disassembling.