bridge gantry crane are widely used in industrial and mining enterprises as a crane, a locomotive depot is now more than one attachment overhead crane, daily use of frequent, heavy workload. Bridge crane can work directly affects the locomotive maintenance tasks and personal and equipment safety.
Bridge crane body heavy, a lot of inertia at run time, and the normal operation of
steel crane brakes immediately when inverted, will make the entire run organization with great torque, to the detriment transmission. Severe broken drive shaft, also make the body skew distortion; reverse brakes also make the gear linkage system occurred violent impact, damage gear, resulting in equipment accidents; reverse brakes also make electric power machines produce a very large torque and strong currents, severe motor will burn out.
Reverse brakes also make the air caused by hanging objects swing hanging objects fall occurred. So, at work, in addition to the event in order to avoid the special danger of an accident outside, does not allow reverse brakes.
With the fast development of electronic technology, inverter performance and reliability have been greatly improved, as the
overhead bridge crane drive control system provides favorable conditions.
2013年8月19日星期一
NDT methods crane Analysis
All parts of bridge cranes are not allowed to cracks and damage, agencies are not allowed after the trial and permanent deformation crack damage; some friction wear surface of the part,sino hoist there are strict requirements, some parts inside the equivalent defect size is also clearly defined Some specific parts also have a dedicated quality requirements, and some anti-corrosion coating thickness on the surface has also been provided.
Refer to the specific requirements of various lifting machinery and parts technical specifications, must be based on the corresponding technical requirements for different test objects using appropriate non-destructive testing methods and testing process. Lifting the main NDT methods are: visual inspection, magnetic testing, metal magnetic memory testing, acoustic emission testing, stress-strain test and vibration test,steel crane mainly in the installation and periodic testing of applications, primarily in the manufacture of radiation detection and installation adoption, ultrasonic, magnetic particle and penetrant testing in the manufacture, installation and periodic inspection in both adoption.
The metal magnetic memory testing, stress-strain test and vibration test is mainly used in the stress and structural evaluation and testing. Visual inspection of the main surface of the material state check (without corrosion, delamination, etc.) and metal structure geometry measurements, mainly gage measurements and visual observation.
Ray detection, mainly used in lifting machinery manufacturing butt weld installation process for the detection of less use of equipment in use. Ultrasonic testing can fillet welding material or internal defects were detected. The bridge crane inspection of weld quality is more common method can detect cracks inside the material, white point and inclusions and other defects.
Electromagnetic eddy current testing mainly film thickness measurement, eddy current crack detection, wire rope testing. Eddy current film thickness measurement primarily used for precise measurement of the film thickness values. Eddy current crack detection accuracy with conventional magnetic quite suitable for lifting machinery for rapid crack scanning. Wire Rope Testing - like magnetic flux leakage detected.hoist gantry crane Can be qualitative (broken wire or corrosion, etc.) and quantitative (number of broken wires or cross-sectional area loss) analysis.
Refer to the specific requirements of various lifting machinery and parts technical specifications, must be based on the corresponding technical requirements for different test objects using appropriate non-destructive testing methods and testing process. Lifting the main NDT methods are: visual inspection, magnetic testing, metal magnetic memory testing, acoustic emission testing, stress-strain test and vibration test,steel crane mainly in the installation and periodic testing of applications, primarily in the manufacture of radiation detection and installation adoption, ultrasonic, magnetic particle and penetrant testing in the manufacture, installation and periodic inspection in both adoption.
The metal magnetic memory testing, stress-strain test and vibration test is mainly used in the stress and structural evaluation and testing. Visual inspection of the main surface of the material state check (without corrosion, delamination, etc.) and metal structure geometry measurements, mainly gage measurements and visual observation.
Ray detection, mainly used in lifting machinery manufacturing butt weld installation process for the detection of less use of equipment in use. Ultrasonic testing can fillet welding material or internal defects were detected. The bridge crane inspection of weld quality is more common method can detect cracks inside the material, white point and inclusions and other defects.
Electromagnetic eddy current testing mainly film thickness measurement, eddy current crack detection, wire rope testing. Eddy current film thickness measurement primarily used for precise measurement of the film thickness values. Eddy current crack detection accuracy with conventional magnetic quite suitable for lifting machinery for rapid crack scanning. Wire Rope Testing - like magnetic flux leakage detected.hoist gantry crane Can be qualitative (broken wire or corrosion, etc.) and quantitative (number of broken wires or cross-sectional area loss) analysis.
Bridge crane bridge strengthening scheme
As steel production needs,
bridge gantry crane frequent long at full load lifting of the state of the bridge crane will appear under torsion, lateral bending and other serious problems, greatly shorten the life of the bridge, but not conducive to the safe operation of the crane . Therefore, to be reinforced for overhead crane bridge, in order to improve the carrying capacity of the bridge and the safety factor, Here I share with bridge strengthening scheme:
Need for the reinforcement of the overhead bridge crane girder bridge box-shaped track, a span of 16.5m. Improve the overall carrying capacity of the bridge primarily for the main beam, main beam and side beams connecting welds, end beam three parts to reinforce dangerous section of the program is as follows.
1.1 improve the carrying capacity of the main beam reinforcement scheme
Increasing the cross sectional area of the main beam can increase the moment of inertia, thereby increasing the strength and rigidity of the main beam, the main beam is to improve the carrying capacity of a reliable and effective way. Increasing the cross sectional area of the main beam of the most common methods are the following three kinds, each of the following features:
(A) small box beam welding reinforcement increases large cross-sections to increase the quality of large structural components, structural parts production workload, difficult construction, welding capacity, suitable for large tonnage, larger span Crane beam reinforcement.
(2) increased reinforcement welded channel cross-sectional area smaller than the welded box girder reinforcement method is small, welding capacity, but the increase of the structural parts quality to light, the structure of the production of a small amount of work, construction difficulty, suitable for representing large tonnage, smaller crane girder span reinforcement.
(3) the increase in cross-sectional area Prestressed Reinforcement and welding small box girder reinforcement method considerably, welding a small amount of light to increase the quality of structural components, structural parts produced small amount of work, construction difficulty, suitable for small tonnage overhead gantry crane main beam reinforcement. Taken together, decided to adopt the main beam under the cover plate is welded on the 16th channel reinforcement, and in the cover plate weld a new cover.
1.2 improve the main beam and side beams carrying capacity of the connection weld reinforcement program
Main beam and the end plate connections through the beam web, and the web plate carrying the most shear weld, the weld connecting the bearing capacity of the attachment welds number, length, thickness of the meat is directly related to welding, which increase the connection increase the number of weld seam on the carrying capacity of the most significant effect. Therefore, using a solution to increase the number of attachment welds, which in the original plate and welding the outside of a reinforcement plate.
1.3 improve the carrying capacity of the end beam reinforcement program
Reinforcement required at each end of the beam bridge crane under two wheels, track smaller, and thus end beam to withstand the bending moment is small, so the upper and lower lid force is small, can not reinforced; side beam web is subjected to a more large shear, while at the wheel support section to withstand the most vigorous, therefore, to take the end of the beam web welded steel shearing reinforcement program.
Need for the reinforcement of the overhead bridge crane girder bridge box-shaped track, a span of 16.5m. Improve the overall carrying capacity of the bridge primarily for the main beam, main beam and side beams connecting welds, end beam three parts to reinforce dangerous section of the program is as follows.
1.1 improve the carrying capacity of the main beam reinforcement scheme
Increasing the cross sectional area of the main beam can increase the moment of inertia, thereby increasing the strength and rigidity of the main beam, the main beam is to improve the carrying capacity of a reliable and effective way. Increasing the cross sectional area of the main beam of the most common methods are the following three kinds, each of the following features:
(A) small box beam welding reinforcement increases large cross-sections to increase the quality of large structural components, structural parts production workload, difficult construction, welding capacity, suitable for large tonnage, larger span Crane beam reinforcement.
(2) increased reinforcement welded channel cross-sectional area smaller than the welded box girder reinforcement method is small, welding capacity, but the increase of the structural parts quality to light, the structure of the production of a small amount of work, construction difficulty, suitable for representing large tonnage, smaller crane girder span reinforcement.
(3) the increase in cross-sectional area Prestressed Reinforcement and welding small box girder reinforcement method considerably, welding a small amount of light to increase the quality of structural components, structural parts produced small amount of work, construction difficulty, suitable for small tonnage overhead gantry crane main beam reinforcement. Taken together, decided to adopt the main beam under the cover plate is welded on the 16th channel reinforcement, and in the cover plate weld a new cover.
1.2 improve the main beam and side beams carrying capacity of the connection weld reinforcement program
Main beam and the end plate connections through the beam web, and the web plate carrying the most shear weld, the weld connecting the bearing capacity of the attachment welds number, length, thickness of the meat is directly related to welding, which increase the connection increase the number of weld seam on the carrying capacity of the most significant effect. Therefore, using a solution to increase the number of attachment welds, which in the original plate and welding the outside of a reinforcement plate.
1.3 improve the carrying capacity of the end beam reinforcement program
Reinforcement required at each end of the beam bridge crane under two wheels, track smaller, and thus end beam to withstand the bending moment is small, so the upper and lower lid force is small, can not reinforced; side beam web is subjected to a more large shear, while at the wheel support section to withstand the most vigorous, therefore, to take the end of the beam web welded steel shearing reinforcement program.
2013年8月16日星期五
Weekly inspections and maintenance of overhead cranes matters
As a bridge
sino hoist lifting gear, its production must be guaranteed safety, we recommend you to check once a week maintenance and its contents can have the following aspects:
1 Check the nut on the brake bridge steel crane , cotter pins, positioning plates are complete, the pin on the brake wheel bolts and washers are loose cushion, complete; levers and springs without cracks, 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 is not stuck phenomenon;
2 Check the hoisting mechanism coupling closures fastening screw is loose, the shortage;
3 Check whether there is on track to run foreign body obstruction bridge crane;
4 Check all crane lubrication lubrication in good condition;
5 Check whether the normal transmission agencies, with or without abnormal noise;
6 Check the safety switch and limit switch is accurate, flexible and reliable work, especially the increase in the limit is reliable;
7 Check the hoist gantry crane 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.
Earnest security issues, the construction unit should do this several training points, to avoid accidental damage during construction.
1 Check the nut on the brake bridge steel crane , cotter pins, positioning plates are complete, the pin on the brake wheel bolts and washers are loose cushion, complete; levers and springs without cracks, 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 is not stuck phenomenon;
2 Check the hoisting mechanism coupling closures fastening screw is loose, the shortage;
3 Check whether there is on track to run foreign body obstruction bridge crane;
4 Check all crane lubrication lubrication in good condition;
5 Check whether the normal transmission agencies, with or without abnormal noise;
6 Check the safety switch and limit switch is accurate, flexible and reliable work, especially the increase in the limit is reliable;
7 Check the hoist gantry crane 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.
Earnest security issues, the construction unit should do this several training points, to avoid accidental damage during construction.
Analysis of bridge crane troubleshooting methods
1 When the crane mechanical failure:
If a fault occurs in the body or trolley carts run institutions, should emergency power;
If a fault occurs in the lifting sector, the driver should immediately send an emergency signal:overhead gantry crane Ming alarm, loud warning notice below the staff with the control measures taken to avoid and to immediately start again on the hook lifting mechanism is controlled so that the hook can not produce free fall state;
2 crane failure there is an electrical failure or malfunction illusion:
Turn off the start switch and the driver with emergency switch down the way;
Ground staff with total three-phase bridge gantry crane off the power switch way, cutting off power to effectively control overhead crane failure events to expand, and then stop and check repairs;
For overhead bridge crane illusion failure of the control, less experienced drivers, the operating handle is not exactly stay in the controller's zero due to zero as long as the operating handle complex, failure phenomenon can be avoided.
If a fault occurs in the body or trolley carts run institutions, should emergency power;
If a fault occurs in the lifting sector, the driver should immediately send an emergency signal:overhead gantry crane Ming alarm, loud warning notice below the staff with the control measures taken to avoid and to immediately start again on the hook lifting mechanism is controlled so that the hook can not produce free fall state;
2 crane failure there is an electrical failure or malfunction illusion:
Turn off the start switch and the driver with emergency switch down the way;
Ground staff with total three-phase bridge gantry crane off the power switch way, cutting off power to effectively control overhead crane failure events to expand, and then stop and check repairs;
For overhead bridge crane illusion failure of the control, less experienced drivers, the operating handle is not exactly stay in the controller's zero due to zero as long as the operating handle complex, failure phenomenon can be avoided.
On the bridge crane fault diagnosis technology
General
overhead gantry crane fault diagnosis technology mainly consists of two parts: First, the implementation by the field worker simple diagnostic techniques; two is implemented by professionals sophisticated diagnostic techniques.
Simple diagnostic techniques:
Crane or components of the stress tends to control and abnormal stress test;
Deterioration of the steel crane or the equipment, the trend control and fault detection of abnormal stress;
Cranes or equipment performance, efficiency tends to control and anomaly detection;
Overhead crane or equipment for detection and protection;
Pointed out that the present fault performance parts or structures.
Sophisticated diagnostic techniques: simple diagnostic technique is judged to be "probably abnormal" parts for specialized diagnostics to determine adopt the necessary measures and technologies.
Determining faulty hoist gantry crane forms and types;
Understand the cause of abnormal;
Understand the degree of risk, predict its development outcomes;
Learn to eliminate overhead crane fault state approach.
Simple diagnostic techniques:
Crane or components of the stress tends to control and abnormal stress test;
Deterioration of the steel crane or the equipment, the trend control and fault detection of abnormal stress;
Cranes or equipment performance, efficiency tends to control and anomaly detection;
Overhead crane or equipment for detection and protection;
Pointed out that the present fault performance parts or structures.
Sophisticated diagnostic techniques: simple diagnostic technique is judged to be "probably abnormal" parts for specialized diagnostics to determine adopt the necessary measures and technologies.
Determining faulty hoist gantry crane forms and types;
Understand the cause of abnormal;
Understand the degree of risk, predict its development outcomes;
Learn to eliminate overhead crane fault state approach.
Talking about the current mainstream of development overhead crane
Overhead crane development in our country for nearly five decades of history, fifty years, the basic mechanical structure
overhead bridge crane working device, rotary equipment, travel agencies, etc. for its form and appearance of the shape basically did not change significantly, this is because the basic principle of overhead cranes and performance is not essentially changed.
To meet the massive infrastructure needs and the needs of national defense construction, bridge crane is the general trend of the development of small-scale to large-scale development of small to large hoist gantry crane lifting heavy development, crane current mainstream of development to large and efficient development.
Bridge sino hoist equipment reliability studies to be further improve and perfect, crane work, each hanging weight, lifting height range are different, showing a random phenomenon in the past taken to determine the amount or maximum hoist design, there are deficiencies, the lack of rationality is to maximize the good design should meet the actual situation, which is designed to bridge crane equipment workers endeavors.
To meet the massive infrastructure needs and the needs of national defense construction, bridge crane is the general trend of the development of small-scale to large-scale development of small to large hoist gantry crane lifting heavy development, crane current mainstream of development to large and efficient development.
Bridge sino hoist equipment reliability studies to be further improve and perfect, crane work, each hanging weight, lifting height range are different, showing a random phenomenon in the past taken to determine the amount or maximum hoist design, there are deficiencies, the lack of rationality is to maximize the good design should meet the actual situation, which is designed to bridge crane equipment workers endeavors.
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