Friction-optimised bearings for propellers with folding mechanism in electric motor glider

For this advanced electric motorised glider for two people, bearing products were sought for various locations for the prototype. Firstly, a plain bearing was needed for the blade adjustment of the planned highly efficient propeller with folding mechanism, which had to be virtually maintenance-free. The planning envisaged the use of the bearing in combination with aluminium F52. The bearing should also have a low coefficient of friction. The second point for which a bearing was required was the control system of the aircraft around the vertical axis. It is controlled via a rotary handle on the hand control. The search was on for a robust, cost-effective and maintenance-free solution for the rotary movement.

The pictures document the design principle and the realisation of the glider. For the blade adjustment, the designers opted for the vibration-damping plain bearings made of the material iglidur® J. They were also chosen because they are lubrication-free and therefore maintenance-free in use. For the aircraft's control system, the all-plastic bearing drylin® R is a simple and ideal solution for the application. The top bearing is coupled with an internal double potentiometer that supplies the required electrical signals. A suitable grip is created by covering the three bearings with an elastomer. The temperature resistance of the plastic bearings is important here. In addition, the bearings allow for fault tolerances when moulding with the elastomer.