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 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 gyroscopic roll stabilizer for a boat includes a cavity for liquid heat transfer medium that helps transfer heat from a flywheel shaft to a heat transfer shaft assembly that extends into the cavity. The cavity includes a first portion that overlaps the heat transfer shaft assembly and a reservoir portion that does not, with the second portion acting as a reservoir for the liquid heat transfer medium. The wall of the cavity is shaped such that the first portion is wider than the second portion. When the flywheel is rotating five thousand rpm or more, liquid heat transfer medium in the reservoir is displaced upward into the first portion, and a gas pocket that is present in the first portion when the flywheel is not rotating is displaced into the reservoir, thereby providing better heat transfer when the flywheel is spinning rapidly. Related methods are also disclosed.

A gyroscopic roll stabilizer for a boat includes a cavity for liquid heat transfer medium that helps transfer heat from a flywheel shaft to a heat transfer shaft assembly that extends into the cavity. The cavity includes a first portion that overlaps the heat transfer shaft assembly and a reservoir portion that does not, with the second portion acting as a reservoir for the liquid heat transfer medium. The wall of the cavity is shaped such that the first portion is wider than the second portion. When the flywheel is rotating five thousand rpm or more, liquid heat transfer medium in the reservoir is displaced upward into the first portion, and a gas pocket that is present in the first portion when the flywheel is not rotating is displaced into the reservoir, thereby providing better heat transfer when the flywheel is spinning rapidly. Related methods are also disclosed.

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. The bearing cooling system enables heat generated by the bearings to be transferred through the flywheel shaft to a heat sink disposed within a cavity in the end of the flywheel shaft, or to a liquid coolant circulating within the cavity.

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. The bearing cooling system enables heat generated by the bearings to be transferred through the flywheel shaft to a heat sink disposed within a cavity in the end of the flywheel shaft, or to a liquid coolant circulating within the cavity.

A gyroscopic stabiliser for stabilising motion of an object includes a support for attaching to the object, a gimbal rotatably supported by the support to be rotatable around a first axis, a flywheel rotatably supported by the gimbal to be rotatable around a second axis relative to the gimbal, orthogonal to the first axis, and a rotary damper. The rotary damper has a chamber containing a damping fluid a vane that is rotatable within the chamber and that is coupled to the gimbal and a flow passage allowing flow of the damping fluid from the chamber on one side of the vane to the chamber on the other side of the vane when the vane is rotated.

A gyroscopic stabiliser for stabilising motion of an object includes a support for attaching to the object, a gimbal rotatably supported by the support to be rotatable around a first axis, a flywheel rotatably supported by the gimbal to be rotatable around a second axis relative to the gimbal, orthogonal to the first axis, and a rotary damper. The rotary damper has a chamber containing a damping fluid a vane that is rotatable within the chamber and that is coupled to the gimbal and a flow passage allowing flow of the damping fluid from the chamber on one side of the vane to the chamber on the other side of the vane when the vane is rotated.

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.