Care And Maintenance Of Cranes

1.Daily maintenance
1.1Routine maintenance is routine maintenance, once per shift. The daily maintenance contents are as follows:
(1) Clean the dust and oil on the cab and the fuselage
(2) Check whether the brake clearance is appropriate
(3) Check whether the connecting bolts of each transmission part are loose
(4) Whether the alarm (bell) and safety device are normal, safe and reliable
(5) Check that the brake belt, hook and wire rope are in good condition
(6) Check whether the controller rotates flexibly, whether the contacts are closely matched and whether the ablation is serious
(7) Check and lubricate according to the lubrication regulations

1.2Primary maintenance:
Primary maintenance is generally once a month. The first-level maintenance content is as follows:
(1) All contents of daily maintenance
(2) Lubricate wire ropes, gear couplings, hinge points of brakes, shafts of limit switches, chains, etc. as required
(3) Check whether the oil level of the reducer is between the oil mark scale lines
(4) Check whether the screws of the wire rope pressure plate are tightened
(5) Check the wear of the elastic ring of the pin coupling, if the clearance exceeds 2mm, it should be replaced
(6) Check the wear of the brake wheel and the pin shaft, whether the spring has cracks and permanent deformation
(7) Check whether each rolling bearing operates normally
(8) Check the wear of the slip rings and carbon brushes of the motor and pin shaft, and remove dust and carbon deposits
(9) Check the wear of the wire insulation layer at the nozzle

1.3Secondary maintenance
Secondary maintenance is generally once every six months. The contents of secondary maintenance are as follows:
(1) All contents of first-level maintenance
(2) Oil the rolling bearing
(3) Check the oil amount and lubrication of the long stroke and hydraulic electromagnet
(4) Clean the dirty oil on the open gear and chain, and refill the oil
(5) Check the wear of the hoisting mechanism hook, coupling and reducer gear
(6) Check the insulation of all electrical equipment
(7) Check whether the control panel, protection panel, controller, resistor and the wiring screws of each terminal block are tightened

2.Inspection of control system and maintenance of electrical equipment:

2.1Inspection of power supply, electrical components and control system Inspection items of power supply device, drive device, electrical components, control and operating system of bridge crane. The electrical and control system inspection items of the crane are as follows:
(1)Motor:
Check the insulation resistance of the windings to see if there is any heat. Bearing check lubrication and abnormal noise. Check the slip ring for discoloration, cracks, and loose terminals. Brushes and wires Check for wear and looseness, pressure, attached toner, and sparks on the rotating motor shaft.

(2) Collecting device:
Check whether the sliding wire and the pulley track of the power supply are deformed, worn or damaged, and whether the tensioning device and the anti-shock device are normal. The collector checks whether the mechanical parts are worn or damaged, and whether the lubrication is good. Check whether the fastening parts of the joint bolts are loose or fall off. Check whether the fastening part of the connection is loose or not.

(3) Control system and electrical components:
Check whether the switch, contact part and fuse are abnormal, whether the shape is damaged, and whether the pressure of the hinge and clip of the contact part is appropriate. The contactor checks for contact pressure and contact surface damage. Check whether there is any attachment on the suction surface of the movable iron core. Check the stopper for wear and damage.Check the spring of the relay for bending, deformation, corrosion and fatigue aging. Check the contact surfaces for damage and wear. Carry out the mechanism and operation test to check the operation state.Check the spring of the relay for bending, deformation, corrosion and fatigue aging. Check the contact surfaces for damage and wear. Carry out the mechanism and operation test to check the operation state.

(4) Electrical components and control system:
Check the contact pressure of the clutch plate of the controller operation switch and whether the fasteners are loose. Check the return spring for breakage, deformation, corrosion and fatigue damage. Check lubrication of bearings and gears. Check the insulating rod for cracks and contamination. Check the pendant switch for damage or looseness. Check whether there is any abnormality in the wire introduction nozzle of the resistor. Check the resistor sheet for cracks, damage, or looseness. Check whether the line protection layer is damaged. Whether the brightness of the lighting signal lamp is appropriate and whether it is damaged. Check whether the circuit insulation resistance is abnormal.

3.Crane lubrication
The quality of the lubrication of the crane equipment directly affects the normal operation of each mechanism of the crane. All parts with shafts, holes and mechanical parts with relative motion friction should be lubricated regularly. Therefore, users and maintenance personnel must always check the lubrication points of each lubrication point. Lubrication situation, add oil to each lubricating point on time. According to the needs of users, its lubrication includes distributed lubrication and centralized lubrication.

3.1Distribution of lubrication points of crane equipment:
Both ends of the hook shaft and the thrust bearing under the hook nut
Fixed axle
Wire rope
Each reducer
Gear coupling
Each bearing seat
Motor bearing
Brake hinge points
Bearings for cable conductor pulleys

3.2 Lubrication conditions and lubricating materials:
Crane equipment must use appropriate lubricating grease, regularly lubricated and replaced in time, and the lubricating device and each lubricating point must be kept clean.

3.3 Lubrication precautions:
Lubricants must be kept clean
Different grades of grease cannot be mixed
Frequently check the sealing condition of the lubrication system
Select the appropriate lubricating material and add the grease according to the specified time to carry out the lubricating work.
It is better to use the pressure grease injection method to add grease, and try to avoid adding grease by the coating method. Because the grease is not easy to enter the friction surface, try to push the grease to the friction surface if necessary
Lubrication is only permitted when the crane is completely de-energized
It should be ensured that the pipeline is not squeezed
When the pipeline needs to be disassembled, the pipe end or the connection must be well protected to avoid bumps or mechanical impurities.
Sodium-based grease should not be used in wet areas, because it is highly absorbent and easy to fail.
The rotating parts of each mechanism without grease injection points should be regularly injected with thin oil in the gaps of each rotating part to reduce the wear of several parts and prevent rust.
When the lubrication points are lubricated, they should be turned properly to distribute the grease evenly.
All kinds of lubricating oil should be replaced immediately if it is found to be contaminated or deteriorated if the specified replacement interval has not been reached.