A gyroscopic roll stabilizer for a boat includes a flywheel shaft having a first end and an opposite second end. The flywheel shaft has first and second open-ended cavities formed on opposing ends. A first uneven seal encloses the first cavity, and a second uneven seal encloses the second cavity. The first and second uneven seals are both configured to provide asymmetric sealing such that greater resistance is provided against flow in a primary sealing direction, from a first side toward a second side, than in a secondary sealing direction, from the second side toward the first side. The first side of the second seal faces inward toward the second cavity, and the second side of the first seal faces inward toward the first cavity. The first and second seals are functionally inverted relative to each other. Related methods are also disclosed.

A controller controls precession of a gyroscope that oscillates about a precession axis perpendicular to a spin axis and a roll axis of the gyroscope. To do so, the controller detects a deviation of a center of the oscillation away from a nominal center. The precession is caused by roll of the gyroscope about the roll axis and imposes decreasing amounts of damping upon the roll as the precession moves away from the nominal center. The controller reduces the deviation of the center of the oscillation by applying an asymmetric amount of braking to the precession when the precession and the deviation are in a same direction relative to when the precession and the deviation are in opposing directions.

A system for mounting equipment to a vessel's hull is disclosed. The system comprises a first stringer and a second stringer, where each stringer is attachable to the inside of the vessel's hull. The system also includes a layer of adhesive attaching both stringers to the inside of the vessels hull. Both stringers have a top cap for attaching equipment. Additionally, each stringer has a first vertical side wall connected to a first end of the top cap, a second vertical side wall connected to a second end of the top cap, and two flanged portions. A first flanged portion connects to a lower end of the first vertical side wall, and a second flanged portion connects to a lower end of the second vertical side wall. The system has an open side portion at the bottom end of both stringers.

A system for mounting equipment to a vessel's hull is disclosed. The system comprises a first stringer and a second stringer, where each stringer is attachable to the inside of the vessel's hull. The system also includes a layer of adhesive attaching both stringers to the inside of the vessels hull. Both stringers have a top cap for attaching equipment. Additionally, each stringer has a first vertical side wall connected to a first end of the top cap, a second vertical side wall connected to a second end of the top cap, and two flanged portions. A first flanged portion connects to a lower end of the first vertical side wall, and a second flanged portion connects to a lower end of the second vertical side wall. The system has an open side portion at the bottom end of both stringers.

An anti-roll stabilizer device for boats includes a container adapted to be mounted on a suspension so as to oscillate around a first axis; a mass rotatably supported inside the container so as to form a rotor that rotates around a second axis transverse to the first axis; and a rotor cooling system having a hollow shaft arranged along the second axis, a first and a second cooling chamber sealed from the container of the rotor and from the outside, arranged at the ends of the hollow shaft and communicating through the hollow shaft, the first chamber having an inlet and the second chamber an outlet that are connected to a forced circulation circuit of the cooling fluid so that the cooling fluid can circulate from the first chamber to the second chamber through the hollow shaft and from the second chamber to the first chamber through the circulation circuit.

An anti-roll stabilizer device for boats includes a container adapted to be mounted on a suspension so as to oscillate around a first axis; a mass rotatably supported inside the container so as to form a rotor that rotates around a second axis transverse to the first axis; and a rotor cooling system having a hollow shaft arranged along the second axis, a first and a second cooling chamber sealed from the container of the rotor and from the outside, arranged at the ends of the hollow shaft and communicating through the hollow shaft, the first chamber having an inlet and the second chamber an outlet that are connected to a forced circulation circuit of the cooling fluid so that the cooling fluid can circulate from the first chamber to the second chamber through the hollow shaft and from the second chamber to the first chamber through the circulation circuit.

A gyroscopic roll stabilizer for a boat includes an enclosure mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure, and a flywheel assembly including a flywheel and flywheel shaft, with the flywheel assembly rotatably mounted inside the enclosure for rotation about a flywheel axis. The gyroscopic roll stabilizer also includes a motor operative to rotate the flywheel assembly and disposed inside the enclosure. A motor cooling circuit is configured to transfer heat away from the motor. The motor cooling circuit has a closed fluid pathway for recirculating cooling fluid therein. The fluid pathway includes a fluid channel jointly defined by the motor and the enclosure and having the cooling fluid therein. The gyroscopic roll stabilizer is configured to transfer heat away from the motor to the cooling fluid. Related methods are also disclosed.

A gyroscopic roll stabilizer for a boat includes an enclosure mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure, and a flywheel assembly including a flywheel and flywheel shaft, with the flywheel assembly rotatably mounted inside the enclosure for rotation about a flywheel axis. The gyroscopic roll stabilizer also includes a motor operative to rotate the flywheel assembly and disposed inside the enclosure. A motor cooling circuit is configured to transfer heat away from the motor. The motor cooling circuit has a closed fluid pathway for recirculating cooling fluid therein. The fluid pathway includes a fluid channel jointly defined by the motor and the enclosure and having the cooling fluid therein. The gyroscopic roll stabilizer is configured to transfer heat away from the motor to the cooling fluid. Related methods are also disclosed.

A gyroscopic roll stabilizer includes an enclosure, a flywheel assembly, and a motor. The enclosure is mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure. The flywheel assembly is rotatably mounted inside the enclosure for rotation about a flywheel axis. The flywheel assembly includes a flywheel and flywheel shaft. The flywheel shaft has a first end and an opposite second end; a first cavity formed in the first end and facing away from the second end; and a second cavity formed in the second end and facing away from the first end. The flywheel shaft has a longitudinal passage connecting the first cavity and the second cavity. This longitudinal passage may be used for inspection of one of the cavities and/or an associated seal, from the direction of the other cavity. Related methods are also disclosed.

A gyroscopic roll stabilizer includes an enclosure, a flywheel assembly, and a motor. The enclosure is mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure. The flywheel assembly is rotatably mounted inside the enclosure for rotation about a flywheel axis. The flywheel assembly includes a flywheel and flywheel shaft. The flywheel shaft has a first end and an opposite second end; a first cavity formed in the first end and facing away from the second end; and a second cavity formed in the second end and facing away from the first end. The flywheel shaft has a longitudinal passage connecting the first cavity and the second cavity. This longitudinal passage may be used for inspection of one of the cavities and/or an associated seal, from the direction of the other cavity. Related methods are also disclosed.