Braking system for gyroscopic boat roll stabilizer

1. A gyroscopic boat roll stabilizer configured to be installed in a boat, comprising:

a gimbal including a support frame and enclosure 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;

a braking system for controlling precession of the enclosure, the braking system comprising:

a first actuator connected between the support frame and the enclosure to resist precession in a first direction about the gimbal axis;

a second actuator connected between the support frame and the enclosure to resist precession in a second direction about the gimbal axis;

a manifold connected in a fluid flow path between the first and second actuators; the manifold having a main valve; the main valve connected to the first and second actuators by respective fluid lines that allow fluid flow between the main valve and the corresponding actuator;

wherein the manifold further comprises first and second hydraulic accumulators operatively connected to the main valve on a low pressure side of the main valve.

2. The gyroscopic boat roll stabilizer of claim 1 , wherein the manifold is mounted to remain stationary relative to the support frame while the first and second actuators extend and retract.

3. The gyroscopic boat roll stabilizer of claim 1 , wherein the manifold includes a manifold block; wherein the manifold block comprises coolant passages configured to carry coolant to dissipate heat generated by fluid flow through the main valve.

4. The gyroscopic boat roll stabilizer of claim 3 , further comprising a cooling circuit configured to dissipate heat generated by movement of fluid through the manifold; wherein the coolant passages form a portion of the cooling circuit.

5. The gyroscopic boat roll stabilizer of claim 1 , wherein the first and second actuators each comprise a fluid cylinder and a lockout valve mounted to the fluid cylinder of the actuator, wherein the lockout valve is movable between a locked position preventing precession of the enclosure and an unlocked position.

6. The gyroscopic boat roll stabilizer of claim 1 , wherein the main valve has first and second inputs and first and second outputs; wherein the manifold is connected to the first and second actuators by the respective fluid lines that allow fluid flow between the main valve and the corresponding actuator.

7. The gyroscopic boat roll stabilizer of claim 6 , wherein the fluid lines connecting the manifold to the first and second actuators include a first line that allows bidirectional flow between first actuator and the manifold, and a second line that allows bidirectional flow between the second actuator and the manifold.

8. The gyroscopic boat roll stabilizer of claim 1 :

wherein the first actuator comprises a first fluid cylinder;

wherein the second actuator comprises a second fluid cylinder;

further comprising a first bypass line providing a fluid low path between first and second ends of the first fluid cylinder that bypasses the manifold;

further comprising a second bypass line providing a fluid low path between first and second ends of the second fluid cylinder that bypasses the manifold.

9. The gyroscopic boat roll stabilizer of claim 5 wherein the lockout valve for each actuator is integrally formed with a housing of the fluid cylinder.

10. A gyroscopic boat roll stabilizer configured to be installed in a boat, comprising:

a gimbal including a support frame and enclosure 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;

a braking system for controlling precession of the enclosure, the braking system comprising:

a first actuator including a first fluid cylinder connected between the support frame and the enclosure to resist precession in a first direction about the gimbal axis;

a second actuator including a second fluid cylinder connected between the support frame and the enclosure to resist precession in a second direction about the gimbal axis;

a manifold connected in a fluid flow path between the first and second fluid cylinders;

a first bypass line providing a fluid low path between first and second ends of the first cylinder that bypasses the manifold; and

a second bypass line providing a fluid low path between first and second ends of the first second cylinder that bypasses the manifold.

11. The gyroscopic boat roll stabilizer of claim 10 , wherein the first and second actuators each further comprise a lockout valve movable between a locked position preventing precession of the enclosure and an unlocked position.

12. The gyroscopic boat roll stabilizer of claim 11 , wherein the lockout valve for each actuator is integrally formed with a housing of the corresponding fluid cylinder.

13. The gyroscopic boat roll stabilizer of claim 10 , wherein the manifold comprises a main valve having first and second inputs and first and second outputs; wherein the manifold is connected to the first and second actuators by respective fluid lines that allow fluid flow between the main valve and the corresponding actuator.

14. The gyroscopic boat roll stabilizer of claim 11 , wherein the first and second bypass lines move jointly with the first and second actuators, respectively, with respect to the support frame.

15. The gyroscopic boat roll stabilizer of claim 11 , wherein the first bypass line allows bidirectional flow between the first and second ends of the first cylinder; and wherein the second bypass line allows bidirectional flow between the first and second ends of the second cylinder.