Overhead Cranes Maintenance Guide Keeping Workplace Safe and Efficient

As the core lifting equipment of industrial plant, warehousing logistics, heavy industry manufacturing and infrastructure engineering, bridge crane undertakes the key tasks of heavy object handling, lifting and shifting, and material transfer. It is an indispensable core equipment for modern industrial production.Equipment long-term high-frequency operation, heavy load operation, outdoor or wet workshop environment corrosion, easy to cause parts wear, line aging, safety device failure and other problems.Scientific and systematic maintenance of overhead cranes is not only the core measure to avoid safety accidents and ensure the safety of workshop operations, but also to greatly reduce the failure rate of equipment, prolong the service life of equipment, reduce downtime losses and maintenance costs, and continuously improve the production and operation efficiency of enterprises.This paper provides a complete set of maintenance guidelines for enterprises, can be landing, high standards of overhead crane maintenance.

Importance of Overhead Crane Maintenance

Henan Mine Crane manufactured bridge crane belongs to industrial high-risk special equipment. Standardized maintenance is very important for enterprise safety production, capacity operation and cost control. The core value is mainly reflected in the following three aspects:

Build a strong line of defense for safety production: crane wire rope breakage, brake failure and other failures are easy to cause heavy accidents such as heavy objects falling, casualties and other major accidents, resulting in property losses and safety supervision penalties.Normalized maintenance can detect hidden dangers in advance, avoid operation risks from the source, and conform to the national safety operation and maintenance specifications for special equipment.

Improve overall productivity: sudden equipment failure will cause unplanned downtime, not only time-consuming and labor-intensive maintenance, but also disrupt production plans and delay delivery.Regular maintenance can greatly reduce the frequency of equipment failure, shorten the downtime, ensure the continuous and stable operation of lifting operations, and improve the utilization rate of workshop capacity.

Reduce the overall cost of operation and maintenance: the crane procurement and overhaul costs are high, and the loss of small parts and neglect of maintenance will cause the failure of the whole machine.Fine maintenance can delay equipment aging, prolong equipment service life, reduce replacement, overhaul and shutdown losses, and help enterprises successfully pass annual equipment inspection.

Main Components Requiring Maintenance

Bridge crane has complex structure and strong system linkage, and the whole machine depends on multiple core systems to work together.The loss speed, failure risk and maintenance requirements of different components are different. Accurate locking of core maintenance components and targeted maintenance are the key to improve maintenance efficiency and eliminate operation and maintenance blind areas.The core maintenance parts of the whole machine are mainly divided into four systems, and the maintenance priorities and practical operation standards of each system are as follows.

Hoisting system

Lifting system is the core operation unit of overhead crane, mainly composed of wire rope, hook, drum, pulley, lifting reducer and lifting motor, directly responsible for lifting heavy objects.The system bears heavy load tension, high frequency friction and alternating stress for a long time, which is the structure with the highest failure rate and the most concentrated safety risk.Parts are prone to wear, aging, deformation and even fracture problems, which are the core and key parts of daily maintenance and regular inspection.

Hoisting system maintenance shall focus on core parts detection and maintenance, daily check wire rope condition, strictly control wire breakage, wear, kink and other hidden dangers, follow industry safety standards to ensure rope diameter and number of rings up to standard, and regularly add special lubricating grease.Synchronous check hook without crack, deformation and wear problems, excessive parts immediately replaced.In addition, it is necessary to regularly detect the oil quality and oil level of the reducer lubricating oil, motor operating temperature and noise, so as to ensure stable start and stop of the system and accurate operation without abnormality.

Bridge structure

Bridge structure is the core of the bridge crane load-bearing support frame, mainly by the main beam, end beam, walking track, wheels, couplings and other components, bear the weight of the whole machine and heavy load pressure.Long-term operation of equipment will continue to be subjected to vibration, impact and alternating loads, easily lead to structural fatigue, parts loose, deformation and corrosion problems.As the basic framework of equipment, once the bridge is damaged, it is easy to cause the risk of rail gnawing, deviation and even equipment overturning. The maintenance difficulty and cost are extremely high, so the normal maintenance work must be implemented.

The bridge structure maintenance shall be carried out with regular cleaning and comprehensive inspection, dust, oil stain and rust layer on the equipment surface shall be cleaned regularly, and the welding seam of main beam and end beam shall be carefully inspected for completeness and crack, and all kinds of fastening parts shall be free from loosening and falling off.Focus on detecting the wear state of walking wheels and track flatness, clean up track sundries in time, and avoid rail gnawing and derailment faults.At the same time, check the transmission state of the coupling, and make anti-corrosion treatment for the exposed structure. The maintenance frequency shall be increased under wet corrosion conditions.

Electrical system

The electrical system is the core control center of the Henan Mine Crane manufactured bridge crane, including cables, sliding contact wires, contactors, frequency converters, operating handles and other key accessories, fully responsible for all operating functions such as equipment start and stop, speed regulation, commutation, limit, etc.Equipment long-term operation in dust accumulation, continuous vibration, temperature fluctuation of industrial environment, easy to appear line aging, insulation damage, poor contact, short-circuit leakage and other faults, directly affect the equipment control accuracy, seriously threaten the overall operation safety of lifting operations.

Normal cleaning and accurate detection shall be implemented for electrical system maintenance, dust and oil pollution of electrical cabinet, terminal and sliding contact line shall be cleaned every day to ensure smooth heat dissipation of components.Regularly and comprehensively check cable lines, tighten loose wiring in time, replace damaged and aged cables, and eliminate the problem of false connection and leakage.At the same time, detect the operation status of electrical components such as contactor and frequency converter, repair ablation jam fault, calibrate speed regulation parameters, check reinforced grounding device, and additionally provide waterproof and moisture-proof protection under wet conditions to avoid short-circuit burning hidden danger.

Safety devices

Safety device is the core safety barrier of overhead crane operation, including lifting limiter, travel limiter, overload limiter, buffer, brake, emergency stop button and acousto-optic warning equipment and other key accessories.This kind of device is the key verification content of annual inspection of special equipment, and must be kept 100% sensitive and reliable at all times.The vast majority of safety accidents in lifting operations are caused by failure of safety devices, inadequate daily inspection and failure to regularly check and maintain, which are key links that cannot be ignored in maintenance work.

Daily inspection and regular calibration shall be carried out for safety device maintenance, and emergency stop button, warning lamp and alarm device shall be tested daily to ensure sensitive trigger and rapid response.Regularly calibrate the high and low limit and stroke limit equipment to eliminate the problem of impact and over-travel collision, and calibrate the overload limiter to ensure that the overload alarm stops automatically.Check the working conditions of buffer and brake normally, replace worn parts in time, prohibit unauthorized removal and shielding of safety devices, and completely eliminate protection blind areas.

Overhead Crane Maintenance Schedule

The maintenance of overhead cranes is divided into daily, monthly and annual three-level maintenance cycles according to the equipment operation frequency, operation conditions and component loss rules, forming a standardized and normalized maintenance system to avoid missed inspection, missed maintenance and excessive maintenance, and realizing refined management of equipment operation and maintenance.

Daily inspection

Daily inspection is the most basic normalization maintenance work of bridge crane, which is completed by equipment operators before and after shift. The overall operation is simple and highly targeted.The core function of this inspection is to check the obvious potential safety hazards of equipment in real time, avoid the operation risks of the day in advance, effectively eliminate the sudden failure of equipment, and lay a solid foundation for the safe and stable development of daily lifting operations. It is an indispensable key link in the equipment operation and maintenance system.

Daily inspection requires all-round inspection of equipment status. Before operation, visually inspect the whole bridge for deformation and damage, check whether the wire rope and hook are intact and abnormal, and test the sensitivity and reliability of brake, emergency stop button, limit and alarm device.At the same time, check the normal operation of electrical control parts, check abnormal noise, shaking, deviation, sliding and other faults during no-load trial operation, and timely clean up impurities and oil stains on equipment and tracks.After the operation, power off and clean the equipment, standardize the registration of inspection records, and immediately shut down and report to the authorities if any abnormality is found, so as to prevent the equipment from operating with faults.

Monthly maintenance

Monthly maintenance belongs to refined in-depth maintenance work, which shall be implemented by professional operation and maintenance personnel, which is the key link to make up for the shortcomings of daily inspection.Maintenance is mainly aimed at the core parts of cranes that are vulnerable to wear and are prone to hidden faults. Comprehensive cleaning, precision lubrication, bolt tightening, parameter fine-tuning and other operations are carried out to effectively investigate equipment loss hidden dangers that are difficult to find with the naked eye, delay the aging rate of components, and reduce the incidence of equipment failures from the source.

Monthly maintenance requires comprehensive cleaning of all system components of the equipment, filling special lubricating grease for wire ropes, bearings, wheels and other transmission structures, tightening bolts and terminals of the whole machine.At the same time, fine-tune the brake clearance, replace the slightly worn parts, calibrate the parameters of the limit and overload protection device, check and replace the deteriorated lubricating oil, repair the slight damage of the cable, and perform anti-corrosion treatment on the corroded parts of the equipment. The maintenance data shall be recorded and archived in the whole process.

Annual inspection

The annual inspection of Henan Mine Crane manufactured bridge crane is a comprehensive in-depth maintenance inspection of the whole machine, strictly carried out according to the annual inspection standard of special equipment, and can be completed jointly with professional inspection institutions and equipment manufacturers.The maintenance covers the whole machine structure, core operation system, safety protection devices and various hidden parts. Through comprehensive inspection, overhaul and rectification, and replacement of accessories, hidden faults are completely eliminated to ensure the stable operation of the equipment throughout the year and ensure that it successfully passes the annual inspection of official special equipment.

Annual maintenance requires completion of a number of core operations, nondestructive testing of main beams and end beams, and correction of structural and track deviations.Disassemble and inspect the reducer, motor, brake and other core components, replace aging wear parts and deteriorated lubricating oil.Check the electrical system comprehensively, replace the aging circuit and failed components, calibrate the operating parameters, and verify the accuracy of all safety devices.At the same time, complete the rust removal and corrosion prevention operation of the whole machine, investigate hidden dangers through no-load and load tests, and finally issue a standard annual inspection report for archiving.

Common Crane Problems and Solutions

Bridge crane long-term heavy load operation, complex working conditions, easy to appear high-frequency common fault.Most enterprises make inaccurate fault judgment and improper handling methods, resulting in small faults evolving into big problems, increasing operation and maintenance costs and prolonging downtime.For the three major high-frequency faults in the industry, sort out accurate fault causes and standardized solutions, quickly solve equipment problems and restore normal operations.

Wire rope issues

The wire rope is the component with the fastest loss and the highest failure frequency of the Henan Mine Crane manufactured overhead crane. The common faults include broken wire and strand, excessive wear, corrosion aging, kink deformation, lubrication failure, rope skipping and groove removal, etc., which are mostly caused by heavy load operation, insufficient lubrication, track deviation, debris friction and long-term fatigue operation.Wire rope failure directly threatens the safety of lifting operation, which is the key type of failure control.

Solution: Daily found a small amount of broken wire, slight wear, timely clean the wire rope, supplement special lubricating oil, check the drum, pulley stuck problem, adjust the operating parameters, to avoid local concentrated wear.If the single lay length exceeds the standard, the rope diameter exceeds the standard, the strand is broken, serious corrosion occurs, and the permanent kink deformation occurs, the new wire rope must be immediately shut down and replaced. It is strictly prohibited to continue to use after repair.For rope skipping, groove out of the problem, correct drum, pulley coaxial, clean rope groove debris, adjust wire rope tension uniformity.In long-term humid and dusty environment, shorten the inspection and lubrication cycle of steel wire rope, regularly remove rust and corrosion, and prolong service life.

Brake problems

Brake system failure is one of the most dangerous equipment failures. Common problems are ineffective braking, failure to brake, slipping of the hook, failure to turn on the brake, abnormal brake noise, overheating of the brake, etc. The main causes are brake shoe lining wear is serious, brake gap is too large, main spring fatigue failure, coil burning, obstruction accumulation, brake wheel wear and deformation.

Solution: For the problem of brake failure and sliding hook, stop immediately to check the wear of brake lining, replace it in time if the wear exceeds the standard, accurately adjust the brake clearance and brake torque, and replace the fatigue aged main spring.To solve the problem of brake failure and jamming, thoroughly clean up sundries and oil stains of brake mechanism, check mechanical jamming fault, repair or replace faulty coil and brake screw rod.In view of abnormal brake noise and overheating, polish and repair brake wheel wear and burr, adjust brake concentricity, ensure uniform brake fit and avoid local friction overheating.Regularly clean the brake system, fine-tune the brake parameters, and eliminate the recurrence of brake faults.

Electrical faults

High-frequency faults of electrical system mainly include equipment failure to start and stop, operation jam, unstable speed regulation, short-circuit trip, leakage, alarm failure, limit failure, etc., which are mostly caused by aging of lines, damage of insulation layer, short circuit of dust accumulation, ablation of electrical elements, poor grounding and parameter deviation. The faults are highly random and have a wide influence range.

Solution: When the equipment cannot be started or stopped, and the operation fails, priority should be given to checking the power switch, terminal, and operating handle, tightening the loose line, and replacing the fault switch.Unstable speed regulation and vibration of equipment, maintenance of frequency converter and contactor, calibration of frequency conversion parameters, replacement of ablated contact parts.In case of frequent short-circuit tripping and leakage, comprehensively check the damaged parts of cable insulation layer, repair or replace aged cables, clean up dust and oil stains in electrical cabinets, check grounding devices and eliminate potential leakage hazards.When the limit and alarm devices fail, recalibrate the accuracy of the devices, replace the faulty sensors and alarm elements, and put them into use only after the test functions are normal.Regularly maintain the electrical system against dust, water and moisture to avoid electrical failures caused by environmental factors.

Best Practices for Preventive Maintenance

Preventive maintenance is the core of long-term stable operation of overhead crane, which is different from maintenance after failure. It is the optimal operation and maintenance mode for enterprises to reduce cost and increase efficiency and ensure safety through maintenance in advance, investigation in advance and rectification in advance. The core landing specifications are as follows.

• Establish a standardized maintenance system and clarify the division of responsibilities.Formulate daily, monthly and annual maintenance plans suitable for enterprise equipment working conditions, clarify the post responsibilities of operators, maintenance personnel and management personnel, refine maintenance items, frequency, standards and assessment mechanisms, eliminate perfunctory maintenance, missed inspection and delayed maintenance, and realize normalization, standardization and traceability of maintenance work.
• Strictly standardize equipment operation and eliminate man-made loss.Most of the equipment faults originate from illegal operation. It is strictly prohibited to operate in violation of regulations such as overload operation, inclined suspension, violent start and stop, frequent commutation, etc.Regularly carry out professional training for operators and maintenance personnel, master equipment operation specifications, maintenance points and fault identification methods, and reduce equipment losses and faults caused by artificial operation.
• Adhere to fine graded maintenance and on-demand maintenance.According to the operation frequency, operation condition and service life of the equipment, the maintenance frequency shall be adjusted differentially, the maintenance cycle of high-frequency and heavy-duty equipment and old equipment shall be shortened appropriately, and the maintenance of core load-bearing and safety components shall be strengthened.Eliminate excessive maintenance, ineffective maintenance, accurate matching equipment loss law.
• Improve account management and spare parts reserve.Establish complete equipment maintenance account, fault account and overhaul account, record each maintenance, overhaul, fault problem and rectification scheme in detail, predict equipment loss trend through data analysis, and avoid potential faults in advance.Prepare wire rope, brake lining, electrical switch, bearings and other common spare parts to achieve rapid repair of faults and reduce downtime.
• Strictly control the operating environment and reduce equipment loss.Keep the workshop dry and tidy, and clean up dust, sundries and corrosive media in time.In the open air, wet, acid and alkali conditions, strengthen equipment corrosion, waterproof, dustproof protection, reduce environmental erosion of equipment loss.

Henan Mine Crane Factory Custom

The safe, efficient and long-term operation of overhead cranes cannot be separated from standardized, normalized and refined maintenance systems.As the core special equipment of industrial production, its operation and maintenance management is not a simple fault maintenance, but a full-process system engineering covering core component maintenance, graded periodic maintenance, accurate fault disposal, preventive management and control, intelligent operation and maintenance and brand selection.

Scientific and standardized maintenance system is the core key to safe and stable production, cost reduction and efficiency increase of cranes, which can effectively avoid safety accidents, reduce equipment loss and shutdown loss, and greatly prolong the service life of equipment.As a professional crane manufacturer, Henan Mine Crane Factory not only provides standardized maintenance solutions, full-process operation and maintenance guidance and original spare parts support, but also relies on intelligent operation and maintenance technology to help enterprises build refined management systems, bid farewell to extensive operation and maintenance, and protect long-term and efficient operation of enterprise lifting operations with high-quality equipment and perfect after-sales service.