Propeller device comprising two or more blades mounted on a hub connected to a motor or to a generator by a shaft and a forward spinner with an outer surface having the shape of a surface of revolution around a longitudinal axis in the direction of said shaft, characterized in that: - the mounting arrangement of the blades on the hub is configured for arranging the blades whether in a deployed position or in a retracted position inside the forward spinner; - the forward spinner comprises: - a first movable portion in the direction of the longitudinal axis and a second rotatory portion around the longitudinal axis from a closed position to an open position and vice versa that are configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted; the outer surface of the first movable portion comprising slots suitable dimensioned for allowing passage of the blades through them; the outer surface of the second rotatory portion being formed by first slot covers for covering said slots, less the spaces allocated to the blades in their deployed position, when it is in the closed position; - a third rotatory portion around the longitudinal axis from a closed position to an open position and vice versa that is configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted; the outer surface of the third rotatory portion being formed by second slot covers to cover said spaces. - the mounting arrangement of the blades on the hub is configured for arranging the blades whether in a deployed position or in a retracted position inside the forward spinner; - the forward spinner comprises: - a first movable portion in the direction of the longitudinal axis and a second rotatory portion around the longitudinal axis from a closed position to an open position and vice versa that are configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted; the outer surface of the first movable portion comprising slots suitable dimensioned for allowing passage of the blades through them; the outer surface of the second rotatory portion being formed by first slot covers for covering said slots, less the spaces allocated to the blades in their deployed position, when it is in the closed position; - a third rotatory portion around the longitudinal axis from a closed position to an open position and vice versa that is configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted; the outer surface of the third rotatory portion being formed by second slot covers to cover said spaces. - a first movable portion in the direction of the longitudinal axis and a second rotatory portion around the longitudinal axis from a closed position to an open position and vice versa that are configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted; the outer surface of the first movable portion comprising slots suitable dimensioned for allowing passage of the blades through them; the outer surface of the second rotatory portion being formed by first slot covers for covering said slots, less the spaces allocated to the blades in their deployed position, when it is in the closed position; - a third rotatory portion around the longitudinal axis from a closed position to an open position and vice versa that is configured for allowing deploying or retracting the blades and for keeping the blades deployed or retracted; the outer surface of the third rotatory portion being formed by second slot covers to cover said spaces.