Gyroscopic boat roll stabilizer

A method of operating a controlled moment gyroscope configured for roll stabilization of a boat, said method comprising:

• maintaining a below ambient pressure within a vacuum enclosure surrounding a flywheel assembly, the flywheel assembly including a flywheel shaft mounted for rotation within the enclosure by a bearing;
• accelerating the flywheel assembly to a normal operating speed in 30 minutes or less;
• locking, during the accelerating, the flywheel assembly against precession;
• and
• transferring heat generated by the bearing to a heat transfer member that is rotationally fixed relative to the enclosure and extends into a bore in the flywheel shaft.

A gyroscopic roll stabilizer for a boat, said gyroscopic roll stabilizer comprising:

• an enclosure mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure;
• a flywheel assembly including a flywheel and flywheel shaft mounted within the enclosure so as to rotate with the enclosure relative to the gimbal axis, when unlocked, in response to roll the boat, said flywheel assembly having a moment of inertia greater than 11.7 kg·m2 (40,000 lbm·in2);
• a bearing for rotatably mounting the flywheel assembly within the enclosure so as to rotate relative to the enclosure about a flywheel axis;
• a motor for rotating the flywheel assembly about the flywheel axis and configured to accelerate the flywheel assembly to a normal operating speed in 60 minutes or less;
• and
• a heat transfer member rotationally fixed relative to the enclosure and extending from the enclosure into a bore in the flywheel shaft, the heat transfer member being configured to absorb heat generated by the bearing.

A method of operating a controlled moment gyroscope configured for roll stabilization of a boat, said method comprising:

• maintaining a below ambient pressure within a vacuum enclosure surrounding a flywheel assembly having a moment of inertia of at least 11.7 kg·m2 (40,000 lbm·in2), the flywheel assembly including a flywheel shaft mounted for rotation within the enclosure by a bearing;
• accelerating the flywheel assembly to a normal operating speed in 60 minutes or less;
• locking, during the accelerating, the flywheel assembly against precession;
• and
• transferring heat generated by the bearing to a heat transfer member that is rotationally fixed relative to the enclosure and extends into a bore in the flywheel shaft.

A gyroscopic roll stabilizer for a boat, said gyroscopic roll stabilizer comprising:

• an enclosure mounted to a gimbal for rotation about a gimbal axis and configured to maintain a below-ambient pressure;
• a flywheel assembly including a flywheel and flywheel shaft mounted within the enclosure so as to rotate with the enclosure relative to the gimbal axis, when unlocked, in response to roll of the boat;
• a bearing for rotatably mounting the flywheel assembly within the enclosure so as to rotate relative to the enclosure about a flywheel axis;
• a motor for rotating the flywheel assembly about the flywheel axis and configured to accelerate the flywheel assembly to a normal operating speed in 30 minutes or less;
• a heat transfer member rotationally fixed relative to the enclosure and extending from the enclosure into a bore in the flywheel shaft, the heat transfer member being configured to absorb heat generated by the bearing;
• and
• wherein the gyroscopic roll stabilizer is configured to lock the flywheel assembly against precession at the start of acceleration and to unlock the flywheel assembly before the speed of the flywheel assembly reaches 75% of its normal operating speed.