Screw Spindle For The LBR IIWA Lightweight Robot

The screw spindle developed by SPN Schwaben Präzision is used in applications with the Kuka LBR IIWA lightweight robot. The prototype has already been delivered and is operating successfully. The aim is to relieve the employees of exhausting and monotonous screwing tasks, which often require an ergonomically unfavorable body position, through the use of lightweight robots.

The specialists at SPN have mastered the high demands placed on the drive technology integrated here: the focus is on a minimum weight of 1.8 kg for the entire HRC spindle. Powerful servomotors with a maximum of 25,000 min ^-1 and the smallest servo control on the market with a peak motor current of 30 A and a size of 35 x 30 x 25 mm (length x width x height) are used, which are connected via an Ethercat interface communicates with the LBR.

There are also gearboxes with different gear ratios for the individual torque ranges. Additional cables were routed to the screw tip in order to connect sensors for monitoring. Mechanical protective sleeves are attached to a specially attached thread. These protective sleeves are often required for use in human-robot collaboration to protect the employee from rotating parts and the sharp edges of the screwdriver tip.

To avoid dangerous pressure points, all edges on the screwdriver are rounded accordingly. The employee has the opportunity to intervene in the process at any time or, if necessary, to switch from automated to manual operation. (ud)