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

Tough and vibration-dampening: iglidur and drylin bearings in electric motor gliders

For the pitch control of a highly efficient propeller with folding mechanism, a virtually maintenance-free plain bearing with low friction values is to be used in combination with aluminium F52. The smooth running and vibration-dampening specifications of iglidur J were convincing here. Furthermore, a robust, cost-effective and maintenance-free solution for the rotary movement of the control wheel was sought. The ideal solution here is drylin R solid plastic bearings, which, in addition to the required specifications, are also temperature-resistant.

Profile

  • What was needed: iglidur plain bearing, drylin shaft guides
  • Requirements: The bearings in the glider should be as maintenance-free, robust and cost-effective as possible, and at the same time have the lowest possible friction values.
  • Industry: Aerospace, aviation industry
  • Success for the customer: iglidur J and drylin R bearings offer the customer an ideal solution: They are vibration-dampening and lubrication-free, which also eliminates maintenance.
Electric motor glider

Problem

For this advanced electric motor glider for 2 persons, bearing products for various places were sought for the prototype. First of all, the pitch control of the planned high-efficiency propeller with folding mechanism required a plain bearing that had to be virtually maintenance-free. The planning envisaged the use of the bearing in combination with aluminium F52. The bearing should also have only low coefficients of friction. The second place for which a bearing was needed was the steering of the aircraft around the vertical axis. It is controlled via a rotary handle on the hand control. For this purpose, a robust, cost-effective and maintenance-free solution for the rotary movement was sought.

Solution

The pictures document the design principle and the implementation of the glider. For the pitch control, the designers opted for the vibration-dampening plain bearings made of the iglidur J material. They were also chosen because they are lubrication-free and therefore maintenance-free in use. For the control of the aircraft, one uses drylin R solid plastic bearings, a solution that is as simple as it is ideal for the application. The top bearing is coupled with an internal double potentiometer that supplies the required electrical signals. By covering the three bearings with an elastomer, a matching handle is created. The temperature resistance of the plastic bearings is important here. In addition, the bearings allow for fault tolerances when pressed with the elastomer.

Plain bearings
Plain bearings
Plain bearings

Wolfgang Liehmann, Silent Flight e.V., Weingarten