What’re the use and maintenance of crane in run-in period(Part I)?
When the gantry crane leaves factory, usually it has a run-in period of 60 days which is regulated by manufacturers according to technical features of crane in early use time. 
Run-in period ensures the crane to operate normally and decrease failure rate, thus prolong its service life. At present, some users neglect the special technical demand of new machine in run-in period because of lacking of crane use common sense or tight time limit or hoping benefit as soon as possible. Some users think manufacturers are responsible for maintaining the machine in warranty period, using the machine with overload for a long time will be ok, which leads to frequent initial failure, influences the normal use of crane, shortens its service life and delays the progress of projects. So, we should pay more attention to use and maintenance of crane in run-in period.
(1) main features in run-in period:
1. fast wear rate. spear parts of new machine have a coarse friction surface and smaller surface contact area and uneven surface pressure situation, because of the influence from processing, assembling and adjusting. in the running process, uneven parts of spear parts conflict with each other, which speeder wear of the spear parts. So it is easy to wear the spear parts(especially the surface) in the run-in speed, overload work will lead to damage the spear parts and causes an early trouble
2. bad lubrication. because of smaller fit clearance for new assembly parts and inproper assembly, it is difficult to ensure the uniformity of the fit clearance so that the grease will form even oil film on the collision surface to prevent wearing. bad lubricating reduces lubricating effectiveness and causes abnormal wear in early time. To make matters worse, it will scratch or scuff surface of spear parts, thus cause an accident
3. easy to loose. new spear parts are easy to become flexible because of deviation on shape and fit dimension, alternating load such as shock and vibrating, influcence from heating and deformation and fast wearing.
4. leakage phenomenon. Because mechanical parts are influenced by loosen parts, vibrating and heated machine, the leakage phenomenon will happen at the machine seal surface and pipe coupling; parts of blemishes such as casting and processing that could not be found in the assembly and commissioning process will be disclosed after suffering from vibrating and shocking, the performance is oil (water) leakage.
5. more operating error. Because of lacking knowledge of machine structure and performance (especially new operators), it is likely to lead to failure due to operating error, even mechanical accidents.
