MARVIN Mk3 helicopter drone

For the MARVIN Mk3 helicopter drone, various bearing systems were to be used to articulate the rotor blades and to decouple the tail rotor from vibrations. The drone's area of application placed special demands on the components used, and the following objectives applied above all to the rotor blade linkage: Firstly, a precise and absolutely clearance-free linkage had to be guaranteed, even when several rod ends were connected in series. The metal sleeves ensure secure fastening without impairing the smooth running of the heads. Due to the outdoor use, it was also important that the drone and all individual components were corrosion-free, dirt-resistant and maintenance-free. As perfect flight behaviour of the drone had to be ensured, the solution also had to be as lightweight as possible while fitting into a very limited installation space.

The rotor blades are articulated via a swash plate to transfer the control movement of the actuators to the rotating rotor blades. The push rods, swash plate and rotor blade holders are attached using igubal ® KBRM-03MH rod end bearings. The rotating part of the swash plate is driven by the rotor head via an articulated moving end. This performs an oscillating movement with each revolution of the rotor. The bearing of the moving end and the connection of the two drive legs is carried out with iglidur ® flange bearings of the type WFM-0304-03. The bearings ensure zero clearance in a small installation space and fulfil all requirements for corrosion protection, freedom from maintenance and dirt resistance. The moving end could be made significantly slimmer and lighter than when using ball bearings.
In addition, the entire tail boom of the helicopter was rotatably mounted around its longitudinal axis in order to decouple rotational vibrations around this axis from the tail rotor via a damper design. Flange bearings of type WFM-5560-60 are used here.