The basis of the drive concept was set by Ernst Schneider, an inventor and engineer born in Moravia and working in Austria. Originally this technology had been designed as a variable water turbine. Together with the Voith GmbH technology group, the concept was soon after translated into a flexible marine propeller and registered for patent as Voith Schneider propeller (VSP). The major difference between the VSP and traditional propellers is the position of the rotation axis, which is relative to the direction of thrust.
During one rotor turn, the rotor blade is cyclically pivoted and passes through the neutral blade position twice. The value of the deflection of the offset from the rotor rotation axis defines the extent of the buoyancy, and the position of the offset determines the direction of the buoyancy vector. The concept therefore allows free adjustment of the thrust direction and magnitude without changing the speed.
This type of control consequently provides the ships equipped with such control with an extremely high manoeuvrability because the thrust is subtly dosed and the thrust direction can be changed extremely quickly. A ship equipped with two or more VSP can move to every direction or perform a stationary turn. For this reason, the drive is used mainly for towing vessels, double-ended ferries, passenger ships, floating cranes and vessels that require high manoeuvrability.
Details on the concept can be found on: https://de.wikipedia.org/wiki/Voith-Schneider-Antrieb
The idea of using a cyclogyro or cycloidal propeller as a drive for aircraft can also be traced back to the times of Ernst Schneider. One of the pioneers in this context was the ethnic German inventor Frederick Kurt J. Kirsten, who performed research and development in the USA, at some point together with William Boeing. They filed patents among other things for the “cycloidal flying machine” and for a “propeller for aircraft”. In addition, a multitude of other concepts was developed, which however did not prove successful. In the end, Kirsten sold his patents to Voith GmbH.
A major difference between use as a drive in the navigation industry and application in the aviation industry are the characteristics of the used media. While the dense medium of water allows operating with low speed and the size and weight of the design plays a minor role, the required speed for aviation applications is much higher, and consequently the load on the necessary lightweight construction materials is tremendous. A lack of opportunities to calculate and simulate loads and a lack of suitable materials have doomed the attempts performed at that time to failure.
Around the turn of the millennium, the efforts were revived, and a large number of different concepts were developed, but only few of them were implemented, and for the time being, no prototype had managed to generate the necessary thrust for a test flight. NASA, Bosch Aerospace, Airbus and other established players of the aviation and aerospace industry also studied the concept, but in the end they discontinued their attempts or did no longer make them available to the public. In addition to commercially oriented companies, research facilities and universities also started to perform scientific studies on the subject. It has not been clearly documented who was first in the world to fly with an aircraft that was exclusively operated with cyclogyro rotors. In any case, CycloTech has succeeded.