A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. For smaller units, the bearing cooling system is effective to enable a flywheel with a moment of inertia less than 40,000 lb in.sup.2 to be accelerated at a rate of 5 rpm/s or greater. For larger units, the bearing cooling system is effective to enable a flywheel with a moment of inertia greater than 40,000 lb in.sup.2 to be accelerated at a rate of 2.5 rpm/s or greater.

A gyroscopic roll stabilizer comprises a gimbal having a support frame and enclosure configured to maintain a below-ambient pressure, a flywheel assembly including a flywheel and flywheel shaft, one or more bearings for rotatably mounting the flywheel inside the enclosure, a motor for rotating the flywheel, and bearing cooling system for cooling the bearings supporting the flywheel. For smaller units, the bearing cooling system is effective to enable a flywheel with a moment of inertia less than 40,000 lb in.sup.2 to be accelerated at a rate of 5 rpm/s or greater. For larger units, the bearing cooling system is effective to enable a flywheel with a moment of inertia greater than 40,000 lb in.sup.2 to be accelerated at a rate of 2.5 rpm/s or greater.

A gyroscopic boat roll stabilizer for a boat comprises a gimbal, having a gimbal axis, an enclosure mounted to the gimbal and configured to precess about a gimbal axis, a flywheel assembly rotatably mounted inside the enclosure for generating a torque that is applied to counter a rolling motion of the boat, and a braking system for controlling precession of the enclosure.

A gyroscopic boat roll stabilizer for a boat comprises a gimbal, having a gimbal axis, an enclosure mounted to the gimbal and configured to precess about a gimbal axis, a flywheel assembly rotatably mounted inside the enclosure for generating a torque that is applied to counter a rolling motion of the boat, and a braking system for controlling precession of the enclosure.

A dynamic active control system (DACS) configured for: (1) total vessel pitch axis control by fast symmetric deployment of water engagement devices (WEDs) or controllers, coupled with engine trim adjustments; (2) total roll and heading control by differentially deploying WEDs to counter rolling motions while simultaneously adjusting engine steering position to counter the steering moment associated with WED delta position; and (3) adjustment of the engine steering angle to counter yaw moments produced by gyroscopic stabilization systems.

A dynamic active control system (DACS) configured for: (1) total vessel pitch axis control by fast symmetric deployment of water engagement devices (WEDs) or controllers, coupled with engine trim adjustments; (2) total roll and heading control by differentially deploying WEDs to counter rolling motions while simultaneously adjusting engine steering position to counter the steering moment associated with WED delta position; and (3) adjustment of the engine steering angle to counter yaw moments produced by gyroscopic stabilization systems.

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.

Method of servicing or maintaining a gyroscope of an anti-roll stabilizer onboard of a seacraft. The method comprising a step of providing a seacraft provided with an anti-roll stabilizer. The stabilizer comprises a gyroscope comprising a container housing a rotor including a flywheel and a flywheel shaft that is rotatably mounted within said container by means of two support devices placed inside said container and arranged to support a respective end of said flywheel shaft so as to allow the relative rotation of said shaft with respect to said container. The container comprises a base portion mounted on a suspension held by a frame of the anti-roll stabilizer so as to be able to oscillate around a first axis transverse with respect to a rotation axis of the flywheel shaft. The container further comprises two end portions removably connected to said base portion. The method further comprising the steps of: removing one of the end portions from the base portion onboard of the seacraft; placing back said removed end portion and reconnecting said end portion with the base portion onboard of the seacraft; and pumping out air of the interior of the container of the gyroscope onboard of the seacraft after the container of the gyroscope has been reassembled.

Method of servicing or maintaining a gyroscope of an anti-roll stabilizer onboard of a seacraft. The method comprising a step of providing a seacraft provided with an anti-roll stabilizer. The stabilizer comprises a gyroscope comprising a container housing a rotor including a flywheel and a flywheel shaft that is rotatably mounted within said container by means of two support devices placed inside said container and arranged to support a respective end of said flywheel shaft so as to allow the relative rotation of said shaft with respect to said container. The container comprises a base portion mounted on a suspension held by a frame of the anti-roll stabilizer so as to be able to oscillate around a first axis transverse with respect to a rotation axis of the flywheel shaft. The container further comprises two end portions removably connected to said base portion. The method further comprising the steps of: removing one of the end portions from the base portion onboard of the seacraft; placing back said removed end portion and reconnecting said end portion with the base portion onboard of the seacraft; and pumping out air of the interior of the container of the gyroscope onboard of the seacraft after the container of the gyroscope has been reassembled.