stable performance,high efficiency,easy to be maintained
Tle overhead gantry crane lifting appliance at upper part can turn to adapt the requirements of tunbeling at different directions. It has flexible operating mode, complete safety in dication and overload protection device, which can uttermost safety of operator and equipments. Electrical system adopts PLC variable frequency speed regulating which is propitious to control the mechanisms.Famous manufacturer of fittings is adopted to guarantee the quality of the complete machine. The latest isseud national standards are executed for design, manufacture and inspection od DMG.
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The overhead crane in workshop should not use mechanical lifting, because the top of the rail is close to the bottom chord of roof truss, in addition, the volume and weight of the heavy duty gantry crane are large. Small and medium sized overhead travelling gantry crane used single mast upright integral hoisting, which can improve work efficiency, shorten the construction period, reduce high-altitude operations, the construction procedures are as follows.
1.The height of the mast
The maximum height of the mast is the height from the ground to the roof, minus the operating space between the top of the mast to the roof panel and the height of the sleeper. Minimum height should meet the needs of lifting height.
Since the mast is to be erected at the center of gravity of the travelling gantry crane between the two main girders of the trolley, the trolley must be biased, and the mast should also deviate from the centre line of the plant. The deviation should be determined according to the weight of the car, the weight of the trolley and the bias distance of the trolley.
3.The bottom treatment of the mast
The bottom of the mast should be solid and flat, laying more than two layers of sleepers, can add rail or I-beam sleepers between the two layers when necessary, laying area is determined by calculation according to the endurance, ensure the axial pressure on the ground under the mast.
4.The mast erection method
The mast can be erected by a travelling gantry crane, which is fast and safe, it can also use the crane beam to pull the mast, auxiliary mast can also be used to support mast. When the crane beam is used for erecting the mast, the stress checking of the crane beam bracket is carried out to ensure that the lateral horizontal component does not exceed 1/20 of the sum of the rated lifting capacity of the heavy duty gantry crane and the amount of the trolley.
Erect a mast, will be pre guyropes temporary mast node in the line near the mast truss, the mast was hanging to the position determined immediately, all the mooring rope fastened at the top of the mast, and tightening on the ground. For example, after the lifting of the cable or the cable stayed truss string, the temporary cable wind rope is used to pull the mast, and the fixed cable wind rope is adjusted to the proper position, then the temporary cable wind rope is loosened.
5.Hanging pulley group, set winch
For small and medium-sized travelling gantry crane, generally can be hung two sets of pulleys, lift with two winches, the distance between the location where the winch is set and the center of the mast should be greater than the length of the mast. Winch can be fixed using the plant column root, but should be block in the bundle or other protection.
Transport overhead gantry crane girder, trolley to the lifting position for assembly, after the assembly of the cart, the trolley is placed in the trolley track, and tied firmly to the cart.
For heavy duty gantry crane below 50t, only need two sets of hanging block, generally use the cross binding method, which is: the mast lifting lugs toward the end girder of travelling gantry crane hanging lifting tackle direction, run through the top of the mast pulley rope guide pulley along the bottom of the mast to lead to hoist.
Running rope method. The utility model is characterized in that one side of the cart is crossed by a binding rope through the two card to be bundled in the opening of the beam walking table board, so that the binding rope is in the shape of “8”.
When the mast height is insufficient, the boom of the car moving pulley attached to the beam, in the top surface of the beam erecting beam, both ends of tie hanger, the sling is wound around the bottom of the beam.
The travelling gantry crane lift from the ground 0.3-0.5m, if without any abnormal phenomenon after 10min, then do the shaking test, reliability test of windlass, mooring rope, mast and anchor, after everything is normal, continue lifting.
The heavy duty gantry crane hanging from the ground about 2.5m, build sleeper piles under the crane, and then mount the operating room on the beam. After the installation of the control room, adjust the position of the trolley, this position should be determined by calculation, so that both sides of the mast hanging point can achieve balance. Then the crane lift a small distance from the sleeper, carefully adjust the position of the trolley, to confirm the balance, and then fixed the trolley. Check other lifting facilities to ensure safe and reliability.