Power transmission device with retractable blades

Abstract

The invention is a power transmission device, such as a wheel or track, comprising retractable blades or protrusions that can be used to assist in vehicle traction by exerting pressure on a fluid or granular medium such as sand, snow, mud, or loose soil, and / or to harness kinetic energy by the rotation of such a blade or protrusion within a fluid or granular medium. The main applications are, on the one hand, land vehicles that can adapt their tread to conserve energy at low speeds, or widen it or equip it with protruding treads when necessary, and travel through mud or on or in water; and boats, for which they replace propellers and allow them to navigate shallow waters; and on the other hand, the harnessing of energy from fluid currents. Abstract figure: Fig. 24