Strategies for Using a Simulation in the Development of the Bremen Autonomous Wheelchair

In a calciner of the type having a screw conveyor for advancing material to and through a calcining reaction zone, and wherein the screw conveyor comprises an internally cooled support shaft which is provided within an outer screw flight shaft, an improvement comprising means for controlling the bending stress between the inner and outer shafts is provided. Further, means are also provided for allowing axial movement of one of the shafts relative to the other. The bending stress ranges between the inner and outer shafts are controlled by means of a plurality of bearing members which extend in a generally radial direction with respect to the shafts and which extend between the shafts. The bending stress range is also controlled by the axial position of the bearing members along the shafts. Axial movement of one shaft relative to the other is permitted by the provision of bearing cages around the inner shaft with axial slots formed in the cage. A portion of the bearing member is tracked in the slot and can thus slide axially therein.