Bridge crane use and maintenance

The name on the  bridge gantry crane  performance of the structure using rules and methods for maintenance
An overhead crane components. Bridge crane mainly by mechanical, electrical and metal structure composed of three parts.
1.1 mechanical parts
From the main lifting mechanism, auxiliary lifting mechanism (15t or more only), trolley carts run institutions and agencies. These include: motors, couplings, shafts, brakes, gearbox, drum and wheels.
1.2 metal structure
Mainly by the bridge (main beam, side beams, railings, walkway, trolley tracks), and small cab chassis components.
Electrical part 1.3
By the electrical equipment and electrical lines, including the power plant and crane bodies starting, speed, reversing, braking and stopping other control systems.
2 inspection and maintenance system
overhead bridge crane components as more different techniques for the various components of the features, we will be maintained in the actual work, inspection cycle is divided into weeks, months, years, each cycle including the following:
2.1 weekly inspection and maintenance
Maintenance and inspection once a week, inspection and maintenance as follows:
1) Check the brakes on the nuts, cotter pins, positioning plates are complete, loose, levers and springs without cracks, pin on the brake wheel bolts and washers are loose cushion, complete; brakes are reliable braking. Brake release opening of the brake pads should be less than 1.0mm, and the distance of the gap on both sides of the brake drum should be equal, the pivot pin may have stuck.
2) Check the safety switch and limit switch is accurate, flexible and reliable work, especially the increase in the limit is reliable.
3) Check the wire rope on the drum and pulley wound is normal, without off-tank, channeling, knotted, twisted and other phenomena, wire rope clamp bolts are tightened, whether there is double nut locking devices.
4) Check the hoisting mechanism coupling closures fastening screw is loose, the shortage.
5) Check the transmission mechanism is normal, with or without abnormal noise.
6) Check all lubrication lubrication condition is good.
7) Check the track if there is a foreign body obstruction bridge machine is running.
2.2 Monthly inspection and maintenance
Once monthly maintenance and inspection, inspection and maintenance, we cover every week to the contents include:
1) Check the brake pad wear pads should not exceed 2mm, wheel and brake pad contact area shall not be less than 70%; checks the status of each mounting pin and wear and lubrication conditions, the amount of wear of the pin should not exceed 5% of the original diameter of the small axis and the amount of wear of the mandrel should not exceed 5% of the original diameter and ovality than 0.5mm.
2) Check the wire rope for wear, if there is broken wire and so on, check the wire rope lubrication conditions.
3) Check the hook for cracks, wear and tear of its dangerous section does not exceed 5% of the original thickness; hook nut locking device is complete, set the hook on the various parts are complete and reliable. Hook should rotate flexible, non-jamming phenomenon.
4) Check that all bolts are loose and shortages.
5) Check the motor, reducer bolts fastening the base and individually fastened.
6) Check the gearbox lubrication conditions, the oil level should be within the specified range, measures should be taken against oil leakage sites prevent leakage.
7) of the gears.
8) Check the balance at the rope pulleys for wear on pulleys and pulley shaft lubrication.
9) Check the pulley position, to see whether it flexible, without damage, cracks, particular attention to the wear of the fixed pulley shaft.
10) Check the brake wheel, uneven surface of its work should not exceed 1.5mm, brake wheel should not have cracks, its radial runout should be less than 0.3mm.
11) Check the coupling, which should not be on the key and keyway damage, loose; two coupling between the drive shaft axial string momentum should be 2 ~ 7mm.
12) Check the size of the vehicle operating conditions, should not have gnawing rails, three fulcrum, when the pendulum starts and stops and so on. Check the wheel rim and the tread wear, the wear of the rim thickness should not exceed 50% of the original thickness, wheel tread wear should not exceed 3% of the diameter of the wheel of the original.
13) Check the cart track conditions, to see whether the bolts loose, shortages, pressure plate is fixed on the track, rail cracks and fracture; two tracks whether the gap joints 1 ~ 2mm (summer) or 3 ~ 5mm ( winter), the joint down, left dislocation is more than 1mm.
14) for the crane to conduct a comprehensive clean, clear on dirt.
2.3 Inspection and maintenance half
Maintenance and inspection once every six months, including the month in addition to checking the content outside there should be:
1) Check that all the gear reducer and wear, pitting damage to the tooth surface should not exceed 30% of the engagement surface and a depth of not more than 10% of the original thickness of the teeth (tooth thickness fixed chord); wear of the tooth thickness the percentage of the original tooth thickness does not exceed 15% to 25%; Check bearing condition; replace oil.
2) check whether large, small wheel condition, the wheel bearings lubricated track to eliminate the phenomenon of eating.
3) Check the main girder, end beam welds have to open the main welding, corrosion phenomena, rust should not exceed 10% of the original thickness of the principal stress components whether fatigue cracks; various rails, brackets are intact; inspection girder, end beam and tighten the bolt again.
4) Check the main beam deformation. Check the trolley track situation. Main beam interference under no load should not exceed the span 1/2000; girders bent inwards next level measured length shall not exceed 1/1500; trolley rail track should not produce the phenomenon, rail top face and flank wear ( sided) volume must not exceed 3mm.
5) Check the reel case, reel wall wear should not exceed 20% of the original wall, rope groove hump does not strain the tip.
6) Tighten all bolts on the steel crane  and fastening bolts.
2.4 crane lubrication
Lubrication is to ensure the normal operation of the machine, to extend the life of parts, improve efficiency and safety of the important measures. Maintenance personnel should fully understand the importance of lubrication equipment, always check the lubrication of all moving points, and regularly add oil to each lubrication points (grease).
2.4.1 The main bridge crane lubrication
① bridge machine winch; ② kinds of bearings; ③ each gear couplings; ④ reducer; ⑤ rope; ⑥ hinge point on the brake.
2.4.2 Lubrication Precautions
One) to keep lubricant (grease) clean;
2) different grades of lubricating oil (fat) should not be mixed;
3) selection of a suitable lubricant (grease) at the stipulated time for lubrication;
4) using pressure greasing France (grease gun or pump, screw-type oil cup) add grease, so you can put grease pushed the friction surface to prevent his hand when not enter the friction surface;
5) wet areas should not use sodium based grease, because of its hydrophilic, easy to lapse;
6) The agency did not oiling point rotating parts, should be regularly rotated with dilute oiler in the gap, in order to reduce mechanical friction and prevent corrosion.