外文文献:Technology status and Development trend of Stacking crane1 OverviewStacking crane is a special crane as of version of the warehouse and developed to appearSpecial crane, commonly referred to as the pile of chop machine, piling machine is three-dimensional storehouse of the most important lifting transportation equipment, represents the sign of three-dimensional warehouse characteristics. Its main use is:In the top shelf of the warehouse in orbit, will be located at the mouth of the