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Maintenance of Port Cranes
Release Time：
2025-07-09 09:19:11
The outgoing operator shall carefully conduct a spot inspection of the crane before handover. Problems that can be resolved shall be addressed prior to handover; for problems that cannot be resolved immediately, the operator shall report them promptly, implement supervised operation for the parts with potential hazards, and keep a handover record at the same time.
I. Regulations on Inspection and Maintenance by Maintenance Personnel
Conduct inspection in accordance with the inspection standards.
If faults or potential hazards are found and cannot be handled on-site, report to the production dispatching office in a timely manner.
II. Regulations on Equipment Lubrication and Lubrication Schedule
Lubrication tools shall be clean; oil cans and oil drums must be covered. Thin oil shall be filtered, and all types of oil used shall meet the oil quality standards.
Lubricate each bearing once in accordance with the lubrication standards, and the oil filling volume shall not exceed two-thirds of the bearing cavity.
Lubricating oil shall be added to gear couplings once every three months.
Add oil to reducers in accordance with the oil level gauge. The oil change interval shall not exceed 12 months, and the gears shall be kept well-lubricated.
For detailed lubrication standards, refer to Appendix 1 Lubrication Standards for Portal Jib Cranes.
III. Regulations on Regular Testing and Adjustment of Equipment
1. Electric Motors
1.1 The stator insulation of each electric motor shall not be less than 1 MΩ, and the rotor insulation shall not be less than 0.5 MΩ. The secondary copper rings shall be free of burning marks, and the brush wear shall be within the specified range.
1.2 Check whether the pressure of the brush holder springs is consistent; the pressure shall be adjusted to 0.015–0.02 MPa, and no sparking shall occur during operation.
1.3 Check whether the power supply voltage meets the requirements; if it is lower than 85% of the rated value, the motor shall be shut down.
1.4 Check whether the electric motor makes normal noise during operation, whether there is vibration, and whether the bearings are short of oil and overheated.
1.5 The contact area of the carbon brushes shall not be less than 90%, and the pressure of the carbon brush springs shall not be less than 20 kPa.
2. Brakes
2.1 Inspect the movable parts daily to ensure they remain flexible, operate accurately and reliably, and show no signs of burning or wear. Any parts that are broken, cracked, or severely worn shall be replaced in a timely manner.
2.2 The insulation of the electromagnetic coil shall not be less than 1 MΩ, and there shall be no loose connection in the grounding system.
2.3 The surface of the brake drum shall be free of oil stains, with uniform wear and no cracks or rope marks. The temperature during friction shall not exceed 200℃.
2.4 During operation, the brake must maintain stability and uniformity. If severe vibration is detected, adjustments shall be made promptly.
2.5 The RKW brake is a normally open, hydraulically driven, horizontally mounted brake. It is controlled by a foot-operated hydraulic pump to achieve arbitrary braking. Equipped with a manual closing (brake application) device, it can be used to maintain braking when necessary in non-operating conditions.
3. Reducers
3.1 Inspect once a day. No abnormal vibration shall occur, and the anchor bolts shall be complete and secure. Replenish or replace oil in accordance with the schedule and seasons, and the oil filling volume shall not be lower than the scale on the oil dipstick.
3.2 Carefully check for abnormal noises every day. If any abnormal phenomena are found, they shall be handled and reported in a timely manner.
3.3 Regularly inspect the gear meshing condition; the tooth surface contact shall be in good condition.
3.4 The oil temperature shall not exceed 80℃ during operation.
4. Drums and Pulleys
4.1 Inspect the drums, pulleys, pulley housings, and pulley flanges daily for defects such as cracks, damage, wear, and edge chipping.
4.2 Drums shall be scrapped when the wall thickness wear reaches 20%.
4.3 Apply lubricating grease to the bearings in accordance with the specified requirements.
5. Wire Ropes
5.1 Inspect the wire ropes every shift for issues such as bending, broken wires, and wear (wear shall not exceed 15% of the original dimension), and handle any problems promptly.
5.2 Normal lubrication shall be ensured, with oil added once a week.
6. Hook Assemblies
6.1 Inspect the wear condition of the hook’s critical section, the flexibility of its rotation, whether the hook shaft has cracks, and whether the retaining plate is secure every shift.
6.2 Inspect whether there are cracks on the root diameter of the thread at the hook’s tail or in the undercut between the thread and the shaft.
6.3 When the wear depth of the hook’s critical section exceeds 10% of its height, the hook shall be required to be replaced.
7. Wheels and Rails
7.1 Inspect the lubrication of the wheels to ensure it is in good condition. Clean and add oil regularly as specified (usually every 2–3 months).
7.2 Check the wheel treads for defects such as sand cracks; the surface shall be flat and smooth.
7.3 Inspect whether the rails are straight, if there is any change in the gauge, and check the conditions of welds and wear.
8. Couplings and Shafts
8.1 Inspect all types of couplings every shift to check if the connection is good and reliable, the lubrication and wear conditions of the gears in gear couplings, and whether there are cracks or other defects on the coupling bodies.
8.2 Check during operation for issues such as looseness, axial movement, and radial runout; if any of these issues are found, they shall be eliminated promptly.
8.3 Inspect the shafts for phenomena such as bending, rusting, and cracking.
9. Metal Structures
9.1 Inspect the camber of the main beam, the lateral bending of the bridge beam, and whether there is deformation in the bridge beam web, etc.
9.2 Inspect other structural components, including whether the platform handrails, connecting bolts, and rivets have rust, looseness, or local deformation, and whether the welds have cracks, etc.
10. Resistor Boxes and Electromagnet Control Boxes
10.1 The lead wire terminals of the resistors shall be in good condition, with no insulation burnout. The resistors shall have no broken segments and no sparking during operation, and all screws must be tightened.
10.2 The temperature rise of the resistors shall not exceed 300℃, and the resistor surfaces shall be kept clean.
10.3 The electromagnet control boxes shall be clean and intact, with all internal components complete and functioning normally.
11. Switchboards and Electrical Equipment
11.1 Coils shall be free of burning marks, their insulation resistance shall not be less than 1 MΩ, and there shall be no grounding faults, loose connections, or open circuits.
11.2 If contacts are burned, uneven, or pitted, they shall be dressed with a file or polished with abrasive cloth.
11.3 Inspect contactors and relays every shift to ensure they operate flexibly, and check that all terminal connections are free of looseness.
11.4 Check all fuses for blown-out conditions; copper wires are strictly prohibited from being used as a substitute for fuse wires.
11.5 Inspect contactor contacts for overheating; the contact pressure between moving contacts and fixed contacts shall not be less than 2.5 N.
12. Controllers
12.1 Inspect that the contact pressure of the contacts and contact plates is between 10–17 N, and that the bonding surfaces of all contacts and contact plates are aligned in a straight line to ensure good contact.
12.2 Pay attention to whether the terminal bolts of the controller are tight and whether the lead wires are subject to mechanical extrusion.
12.3 For the interlocking switches of each controller, the pins shall be tight; the interlocking keys and transmitters shall be properly lubricated to ensure they are free of rust, function well, and have no jamming.
V. Regulations on Equipment Defect and Fault Handling
1.Equipment supervisors, maintenance personnel, and operators shall conduct spot inspections and regular patrols on the equipment under their responsibility to promptly identify defects and eliminate faults.
2.If the identified defects or faults are beyond their jurisdiction or cannot be resolved immediately, they shall report to the production dispatching office immediately, and the office shall convene relevant technical personnel to conduct on-site analysis and confirmation. Defects and faults that require handling shall be repaired urgently; for those confirmed to be repairable at a later time, spot inspections and patrols on the relevant parts must be strengthened, and monitoring shall be implemented.
VI. Requirements and Regulations on Maintenance Records (for Equipment Inspection, Testing, Adjustment, Accidents, Faults, Lubrication, etc.)
6.1 Electric motors shall be cleaned and lubricated once a year.
6.2 The main beam shall be inspected once a year.
6.3 Lubricating oil shall be replaced in accordance with the oil quality replacement cycle.
VII. Regulations on Equipment Handover
The outgoing operator shall carefully conduct a spot inspection of the crane before handover. Problems that can be resolved shall be handled before handover; for problems that cannot be resolved, the operator shall report promptly, implement supervised operation for the parts with potential hazards, and make handover records at the same time.
The system of direct person-to-person handover shall be strictly implemented. If no one takes over the shift, or if the outgoing operator leaves the crane without the successor’s confirmation, the outgoing operator shall be responsible for all problems arising therefrom. The successor shall be responsible for all problems caused by missed inspections during the handover.
The incoming operator shall conduct inspection and test runs in accordance with the items specified in the standardized operation regulations, check and count the tools, and may take over the crane only if they confirm that everything is normal.
After the handover between the two parties is completed, both parties shall sign on the handover record.
Copyright ? 2025 Nantong ZhonghaiSteelStructure Co.,Ltd. All Rights Reserved Su ICP Registration No. 19013745-1 Technical Support: SUEASY