Preparation before Crane Operation
- All aspects of preparations must be done before lifting operation to prevent accidents due to unexpected situations. The contents of operation preparation are: preparation and inspection of lifting appliances, including wire rope, shackle, clamp, basket, etc.; preparation of auxiliary appliances, including skid, crowbar, wire hook, etc.; determination and cleaning of the falling place, which shall be flat and spacious.
- The contact signal is the bridge between the driver and the crane operator. Many accidents are caused by information exchange errors. Therefore, both ground command signal and crane warning signal shall be contacted according to the specified standards. In particular, the crane driver can only operate after confirming the command signal, hanging status, operation channel and landing space.
- Before binding components or equipment, the appropriate binding point shall be determined according to the shape and center of gravity position; secondly, the angle between the steel wire rope and the horizontal plane during lifting shall be considered for binding heavy objects, and in the case of stress, the angle shall be 45 °. Then when binding the objects with edges and corners, board, tire, sack and other objects shall be padded to avoid damage to the steel wire rope. Next, it is necessary to consider whether it is convenient to remove the lifting object when binding the heavy object, and whether the sling will be pressed or damaged after the heavy object is placed in place; finally, when lifting various spare parts, it is necessary to adopt suitable clamps to ensure stable lifting.
Inspection of Crane Lifting Mechanism
The lifting part of crane is the most important part of crane inspection and maintenance, because it directly affects the frequency of a crane accident.
General steps of crane lifting mechanism inspection:
- Check the drum surface for wear, surface lubrication, wire rope jumping, drum rust, etc.
- Check whether the steel wire rope has defects, damages, broken strands, broken wires, loose strands and other phenomena, and check whether the pressure block of the steel wire rope is loose.
- Whether there is any damage on the outside of the hook, whether the bolts are loose, whether the safety buckle is in good condition, and whether the hook head rotates freely.
- Check whether the lifting limit switch is fixed, whether the lock nut is tight, and whether the functions and wiring of the limit switch are loose.
- Check whether the fixing of the lifting motor is reliable, whether the wiring inside the junction box is firm and whether there is noise when the motor is running.
Maintenance Knowledge of Gantry Crane
The working performance and service life of crane mechanisms depend on lubrication to a great extent.
When lubricating, please refer to the manual for the maintenance and lubrication of mechanical and electrical products. Grease should be injected once a week for traveling crane and crane trolley. When the winch is filled with industrial gear oil (sy1172-80) 200, the oil level should be checked frequently and replenished in time.
2. Wire rope
Pay attention to the broken wire condition of the wire rope. If there is broken wire, broken strand or abrasion reaches the scrapping standard, the new rope should be replaced in time. The steel wire rope that can be selected includes phosphating coating steel wire rope, galvanized steel wire rope and smooth surface steel wire rope.
The spreader must be checked regularly.
4. Pulley block
Mainly check the wear of rope groove, whether the flange is cracked and whether the pulley is stuck on the shaft.
Check the flange and tread regularly, and replace the new wheel when the wear or crack of the flange reaches 10% thickness.
When the diameter difference between the two driving wheels on the tread exceeds D / 600, or there are serious scars on the tread, the wheel shall be polished again.
Check once per shift.
The brake shall act accurately and the pin shaft shall not be stuck. The brake shoe should fit the brake wheel correctly, and the brake shoe clearance should be equal when the brake is released.
7. Causes and preventive measures of oil leakage of reducer
There are three common reasons for oil leakage of reducer
- Due to the unreasonable design of the manufacturer: in the design process, there is no special vent or the vent is too small and other design defects will cause the internal and external pressure of the reducer to be unbalanced, resulting in leakage fault, and eventually lead to the leakage fault of the reducer lubricating oil. It is also possible that in the process of long-term use, the joint surface of the reducer is not tightly sealed, resulting in leakage.
- Due to the limited level of processing technology, the precision of the contact surface of the box is not enough, resulting in poor sealing performance and oil leakage.
- Due to the improper maintenance of operators or maintenance personnel in the daily use process, the internal pressure is higher than the external pressure due to the improper maintenance of the operators or maintenance personnel. At the same time, too much oil and no tightening of fasteners will cause the joint surface between the two boxes not tight, resulting in oil leakage.
In order to effectively prevent the reducer from oil leakage, the manufacturer should improve the process level and optimize the design scheme: a ventilation device can be added on the filler hole cover to ensure the internal and external pressure is balanced and unobstructed. At the same time, the process precision between the joint surface of the two boxes should be improved in the design process, so as to prevent the oil leakage fault caused by the loose contact surface. At the same time, it is also necessary to do a good job of maintenance in the process of daily use, and regularly check whether the air vent, oil volume, box body and fasteners are in the normal state.