With such an automatic crane system for loading stainless steel pipes, one encounters special environmental conditions. Due to the structural conditions on site, the operator required an extremely low clearance height. The space from the top edge of the rail to the interfering edge of the mobile racking system is only 1,000 mm.
Pipe bundles are automatically placed on and removed from the racks and stored in a warehouse management system. A total of 24,000 storage and retrieval processes take place each year. For feeding the automatic processing machines located in the hall, the requested pipe types are deposited by crane in a corresponding loading magazine of the machine tools. There the pipes are then bent, turned and punched and prepared for further processing. Thus the environmental conditions and oily air are accordingly stressing the material additionally.
Many shelves stand in a confined space. The crane moves over the racks into a very narrow lane. Added to this are the fast turnaround times and the low clearance height of the hall to the upper edge of the mobile racking system.
Energy chains instead of festooning or conductor rails
The structural installation height of the crane girders with a span of 27.5 m, the trolley, the slewing gear and the fixed version load guide was not allowed to exceed 1,000 mm. To find a suitable solution here, the company developed a special interlacing method. This means that the trolley with the trolley track was installed between the crane bridge girders, and the slewing gear was designed so that it could be accommodated in the trolley frame without exceeding the height dimension (the upper edge of the crane bridge girders).
The power supply systems for the trolley drive and the slewing gear posed a further challenge. Only 500 mm height and 300 mm width are available as installation space for the trolley's power supply. Conventional festooning or conductor rails were immediately ruled out due to their low overall height. Only energy supply systems were considered, over which the entire cabling of the main power supply for the drives, the control cables and the Profibus cable are guided.
Reverse arrangement for trolley's power supply
For the trolley's power supply, two reverse horizontally arranged energy chains were used, which are located above the trolley frame laterally on the inside of the main girder. The travels of the trolley's power supply are 21,245 mm for the first and 17,650 mm for the second system. The speed is between 0 and 60 m/min. For the slewing gear power supply, two reverse horizontally mounted igus energy chains are also used on the slewing gear frame. With this system a rotation angle of 270° is achieved. Here the speeds are between 0 and 4 rpm.
Here, the four-part e-chain E4/4, Series 3838 is used as a pre-assembled readychain energy supply system with all required cables. In addition, the entire trough material is supplied, which includes both standard troughs for the energy chains in gliding application and special troughs for the chains with reverse bend radius.