Bird-Johnson Company

Rolls-Royce Naval Marine, Inc.

Rolls-Royce Marine North America Inc.

Francesco Lanni

Gregory P Platzer

Neal A Brown

John A Eckhart

A fixed-pitch bolted propeller includes: a hollow hub body configured for attachment to a rotatable shaft, where the hollow hub body includes connection ports circumferentially distributed on an outer surface thereof; propeller blades, where each of the propeller blades terminates in a blade flange attached to the outer surface of the hollow hub body at one of the connection ports; retention plates positioned on an inner surface of the hollow hub body adjacent to the connection ports, where the retention plates include threaded recesses; and bolts extending through bolt holes in the blade flanges and the connection ports and into the threaded recesses of the retention plates to secure the propeller blades to the hollow hub body. The retention plates and the bolts each comprise a material having a tensile strength of at least about 125 ksi and/or a fatigue endurance limit of at least about 50 ksi.

Fixed-pitch bolted propeller

A propeller or propeller blade is manufactured using lattice block material to provide a structure which is generally hollow but for a three-dimensional lattice of support spars. The propeller or propeller blade, being predominately hollow, is substantially lighter than a solid cast propeller or propeller blade while retaining the desired strength due to the three-dimensional lattice of support spars.

Propeller

A waterjet propulsion pump (,) is mounted in an opening in a fully submerged intermediate transom (,) located forward of the stern transom (,) and at the aft end of a dependent structural pod (,) on the hull bottom with the pump discharge nozzle (,) lying aft of the intermediate transom. A steering nozzle (,) is mounted on the discharge nozzle (,) for pivotal movement about an axis that lies in a vertical plane. At least one reversing deflector (,or,and,) is mounted for pivotal movement about an axis that is perpendicular to the vertical plane. A rotatable steering shaft (,) operated by a steering actuator located with the hull (,or,) is coupled to the steering nozzle (,or,). A hollow reversing shaft (,) is received telescopically over a portion of the steering shaft and is translatable axially relative to the steering shaft by a reversing actuator (,) located within the vessel hull. A mechanical linkage (,and,) coupled between the reversing shaft and the reversing deflector pivots the reversing deflector between an inactive position and an operative position. Fairings (,) fair to the lines of the pod and to each other cover the sides and bottoms of discharge nozzle, steering nozzle and reversing deflector, and the steering and reversing shafts.

Surface vessel with a waterjet propulsion system

A waterjet steering and reversing apparatus has a steering nozzle mounted aft of the exit nozzle for pivotal movement about a steering pivot axis that lies in a vertical plane and a reversing deflector that is mounted for pivotal movement about a reversing pivot axis for movement between an inactive position clear of a water jet discharged from the steering nozzle and an operative position in which the water jet impinges on a surface that deflects the water jet to a direction having a forward vector. The reversing pivot axis is perpendicular to the vertical plane and spaced apart from the steering pivot axis. A rotatable steering shaft is coupled at its lower end to the steering nozzle, is coaxial with the steering pivot axis, extends upwardly through an opening in the hull, and has an upper end portion located within the hull. A hollow reversing shaft received telescopically over a portion of the steering shaft is translatable axially relative to the steering shaft. A steering actuator received within the vessel hull and coupled to the steering shaft imparts rotation to the steering shaft. A mechanical linkage coupled between the reversing shaft and the reversing deflector pivots the reversing deflector between the inactive position and the operative position upon axial translation of the reversing shaft relative to the steering shaft by a reversing actuator received within the hull.

Steering and reversing apparatus for waterjet propulsion systems

An impeller for a marine waterjet propulsion system has blades that are configured to reduce cavitation, vibration, noise and physical damage to the major components of the propulsion system or host vessel of installation. The leading edge of each blade of the impeller is skewed forwardly over at least the outer 70% of its span, the forward skew being maximum at the tip and being not less than 35.degree.. The impeller has a blade area ratio of not less than 1.5. The chord lengths of each blade increase progressively from the point of minimum skew to the tip, resulting in reduced loading in the cavitation critical region. A partial or full tip band may be affixed to the blade tips.

Impeller for marine waterjet propulsion apparatus

A surface vessel has a hull that is configured to provide a mounting location for a waterjet pump propulsion system that is fully submerged under substantially all operating conditions of the vessel. A waterjet propulsion pump is mounted in an opening in the mounting location of the hull. At least the aft portion of the pump exit nozzle extends aft of the mounting location. A rotatable steering nozzle is coupled to the lower end of a rotatable steering shaft. A rotatable reversing deflector is coupled to the lower end of a rotatable reversing shaft that is either concentric with or parallel to the steering shaft. The steering shaft and reversing shaft extend upwardly through a shared opening or a pair of openings in the hull. Steering and reversing actuators associated with the steering and reversing shafts are located within the hull. A pair of steering deflectors in a 'clamshell' relationship is an alternative.

Growing community of inventors

Walpole, MA, United States of America

Francesco Lanni