A propeller (1) and a respective use method are described, comprising a cylindrical casing (3), a hub (2) couplable to an engine and rotatably mounted at least partially in the cylindrical casing of the propeller, and at least one blade (4) rotatably pivoted to the cylindrical casing. The hub (2) is rotatable with respect to the cylindrical casing of the propeller, or vice versa, to adjust the fluid dynamic pitch of the at least one blade (4). The propeller further comprises at least one elastic element (8) interposed between the hub (2) and the cylindrical casing (3) and it is characterized in that the elastic element (8) is preloaded to prevent its deformation until the resistant torque opposing the propeller rotation is lower than the torque generated by the preload of the elastic element (8), wherein said at least one blade is arranged on at least one first fixed fluid dynamic pitch before the deformation of the elastic element (8) begins. It is further described a flat spring (100) for propellers, which has a longitudinal development line (MS) and comprises a plurality of notches (103) transversally arranged with respect to the longitudinal development line. At least two distances (MD) between successive notches (103) are different from one another and/or at least two notches (103) are different from one another.

A propeller (1) and a respective use method are described, comprising a cylindrical casing (3), a hub (2) couplable to an engine and rotatably mounted at least partially in the cylindrical casing of the propeller, and at least one blade (4) rotatably pivoted to the cylindrical casing. The hub (2) is rotatable with respect to the cylindrical casing of the propeller, or vice versa, to adjust the fluid dynamic pitch of the at least one blade (4). The propeller further comprises at least one elastic element (8) interposed between the hub (2) and the cylindrical casing (3) and it is characterized in that the elastic element (8) is preloaded to prevent its deformation until the resistant torque opposing the propeller rotation is lower than the torque generated by the preload of the elastic element (8), wherein said at least one blade is arranged on at least one first fixed fluid dynamic pitch before the deformation of the elastic element (8) begins. It is further described a flat spring (100) for propellers, which has a longitudinal development line (MS) and comprises a plurality of notches (103) transversally arranged with respect to the longitudinal development line. At least two distances (MD) between successive notches (103) are different from one another and/or at least two notches (103) are different from one another.

An electrically actuated propeller pitch control system includes a propeller hub assembly, a propeller assembly, and a crosshead drive system. The propeller hub assembly rotates about the central axis during operation of watercraft. The propeller assembly is configured to selectively rotate a propeller blade. The crosshead drive system includes an electric motor, a transmission, and a lead screw that rotates about the central axis.

An electrically actuated propeller pitch control system includes a propeller hub assembly, a propeller assembly, and a crosshead drive system. The propeller hub assembly rotates about the central axis during operation of watercraft. The propeller assembly is configured to selectively rotate a propeller blade. The crosshead drive system includes an electric motor, a transmission, and a lead screw that rotates about the central axis.

There is described an assembly having a plurality of screws, a propeller and a related method for adjusting the fluid dynamic pitch of the blades of the propeller. The propeller has at least one blade pivoted rotatably to a cylindrical propeller casing, a hub coupled to an engine and mounted coaxially inside the propeller casing, a kinematic mechanism coupled to the hub and/or to the propeller casing, and to the blade for adjusting the fluid dynamic pitch of the propeller. The hub is rotatable with respect to the cylindrical propeller casing, or vice versa, for at least one non-zero angular interval () of operation of the kinematic mechanism for adjusting the fluid dynamic pitch and is also integral with a contact surface movable between disengagement from and engagement with, direct or indirect, at least one relative abutment integral with the cylindrical propeller casing which defines a limit stop of the angular interval (). The plurality of screws has at least two different screws and the propeller has a seat for complete installation of a screw selected from the plurality of screws, and the limit stop abutment has a region of screw selected from the plurality of screws installed in the seat provided in the propeller.