Solution
In the case of the Krones retractable star wheel, three
iglidur J plain bearings are now found in the clamp carrier. The two upper gliding bearings form the fixed bearing; the lower gliding bearing, the torque arm, acts as a floating bearing. The Krones developers also rely on
iglidur J flange bearings for the cam roller. They ensure that the plastic cam roller rolls cleanly and evenly on the cam track. The radial forces of the cam roller are transmitted reliably and with low friction to the clamp carrier. The rotary latch in turn is mounted in an
iglidur X plastic bearing. With its rolling motion on the control cam, it ensures precise and positionally correct opening and closing of the clamp. Like the clamp carrier housing, the carriage is also equipped with soft stainless steel round guides.
If required, for example in emergency stop situations, the carriage must complete the switching movement within 180ms. This requires a reliable and stick-slip-free sliding movement, as the entire system is accelerated to 2.45g and reaches a speed of 0.44m/s over the short travel distance of 40mm.
The compression springs, which hold the clamp carriers on the pitch circle, are guided on one side by a
iglidur J plastic sliding bush. They centre the compression springs to the clamp carrier and prevent mechanical damage to the highly polished round guide surface.