Higher performance and energy saving in warehouse systems

A significant step in the new design was the use, wherever possible, of composites instead of steel to reduce weight and inertia. This enabled the use of smaller drives, supplied by Lenze, and an increase in dynamic performance. The result was improved acceleration to 3 m/s² and travel speeds with a 2x50 kg load up to 3m/s vertically and 6 m/s horizontally. Customers can see the benefits of improved productivity and lower energy use resulting from the reduced mass and inertia.

Core elements of the drive technology in the project are servo geared motors and intelligent servo drives. Synchronous dynamic servo-motors, and which meet the IE3 efficiency class, are combined with helical bevel gearboxes that are also energy saving with efficiency around 96%. 

The series 9400 servo drives feature an integrated PLC that gives decentralised local control of the motion tasks. The drive profiles for each move are calculated individually by the drive. As the intelligence is in a plug-in module, drives can be replaced in the field by simply swopping the module from the old drive to the new. Furthermore, only a single basic variant of drive needs to be held in stock as plugging in the memory module turns it into an axis-specific version.

The drive technology adds a further layer of benefits to viastore customers. Travel profiles are adjusted by the drives, for example lifting movements are delayed during long horizontal movements to help with stability and allow greater speeds. Where simultaneous starts on storage/retrieval units are requested, automatic offsets are applied to limit warehouse peak currents. Another energy saving feature is automatic switch-off of the drives when they are not needed. Data researched by viastore indicates that typical installations have their SRU’s inactive and in standby mode for as much as 53% of a working week.