Designing and manufacturing high-bay warehouses is a specialty of SSI Schäfer, a German international logistics company. These warehouses feature welded steel beams that are used as horizontal load carriers in shelving systems.

assembly in action 3
SSI Schäfer welds steel beams that are used
in the manufacture of the company’s high-bay
warehouses. Photo courtesy Lenze

Recently, SSI needed to integrate a new welding cell into its plant’s overall control system. The cell measures 16.5 by 7 meters and features 10 six-axis Romat robots made by Cloos. The robots are set up in pairs.

Cloos and Lenze integrated the cell into the control system in just four weeks. The tandem achieved such a quick setup by using Lenze’s L-force Engineering method to determine system parameters and configuration.

The cell’s material flow drive system ensures that all beams are fed, aligned and held in the proper position before being welded by the robots. Cloos selected several Lenze products for the drive system, including Servo Drives 9400, GKS helical-bevel and GKR bevel-geared servomotors, and MDSLS servo spindle motors.

GKS motors have rated torques up to 11,606 newton-meters, GKR motors up to 450 newton-meters. The MDSLS motors handle translational movements.

The servo drives coordinate the feeding of beams into the robots’ working areas. Cloos likes that the drives offer comprehensive modularity and preconfigured solutions for functional motion. In addition, the drives can be equipped with fieldbus and functional modules that use conventional technology or Ethernet-based interfaces.

Cloos uses Ethernet to access the servo drives, which feature an integrated two-port switch that makes it easy to loop communication. The communication modules also enable galvanic separation of the network and base device.

Since installation, SSI Schäfer has run more than 1 million support beams through the welding cell. The cell has experienced no downtime and a reject rate of less than 0.1 percent.

For more information on servo drives, call 800-217-9100 or visit