Aircraft, in particular a personal air mobility aircraft or drone, an annular propeller unit, and a boat comprising this unit

An aircraft, comprising:

• a supporting structure,
• one or more annular propellers, supported in rotation by the supporting structure,
• wherein each annular propeller comprises:
• a rotor ring having a rotor ring axis, and rotatably mounted around said axis within a stationary ring, said stationary ring coaxial with the rotor ring, and forming part of the supporting structure,
• one or more blades that extend radially from a body of the rotor ring towards the axis of the rotor ring,
• at least one motor unit to drive said one or more annular propellers, said at least one motor unit carried by the supporting structure and having an output shaft spaced apart from an axis of each of the one or more annular propellers which are driven thereby,
• said stationary ring including an inner circumferential wall, substantially flush with, and axially on the extension of, an inner circumferential surface of the rotor ring, so as to define with the latter a guide duct for the fluid flow generated by each annular propeller,
• said inner circumferential wall of the stationary ring including a circumferential recess within which the rotor ring is arranged and rotatably supported,
• one or more belt transmissions, each belt transmission of said one or more belt transmission connects each rotor ring of each propeller of said annular one or more propellers which are driven by said at least one motor unit with the output shaft of the at least one motor unit, each belt transmission of the one or more belt transmissions comprising an endless belt, each endless belt engaged on a pulley mounted on the output shaft of the at least one motor unit and on an outer circumferential surface of the rotor ring body, inside said circumferential recess of each of the one or more propellers, each stationary ring of each propeller of the one or more annular propellers having at least one opening for the passage of each belt of said one or more belt transmissions;
• one or more wing surfaces incorporating annular propellers whose rotor rings are driven, individually or in groups, by one or more motor units by respective belt transmissions, and
• a tail provided with one or more annular propellers with horizontal axis, the rotor rings of which are controlled, individually or in groups, by one or more motor units by respective belt transmissions.