Why have the rotor shafts not got a featherkey way?
Festo uses couplings with friction locking. These have zero clearance and are wear-free, with 200% overload protection. Slot and featherkey connections have major disadvantages for positioning: A certain minimum clearance is required at the side edges (angular clearance) for mounting. This leads to backlash and thus to low positioning accuracy. In addition, the edges are ‘deflected’ over time, resulting in greater angular clearance between the coupling hub and the motor shaft. Slot and featherkey connections are therefore used on electric motors that operate continuously in one rotation and torque direction and are thus unsuitable for reversing operation.
