Ship's propeller with nozzle - has blades rotatable about axis-radial axes and tips spherical-surfaced, centred on axes intersection point

摘要

The ship's propeller inside a nozzle has blades rotatable about axes intersecting at a point on the propeller axis. The blade (7) are bounded by surfaces (12) following the periphery of a circle whose centre is the blade rotation axes' intersection point (0), and the nozzle (2) inside surface embodies a spherical zone (Z) centred on that same point. The sphere's radius (R1) exceeds the circle's (R2) by the width of a predetermined gap (D). Pref. the blade tip surfaces also form part of a sphere, with the same centre and the zone extends further downstream of the rotation-axis plane (p) than upstream.