Braking System for Gyroscopic Boat Roll Stabilizer

Abstract

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.

What is claimed is: 
     
         1 . A gyroscopic boat roll stabilizer configured to be installed in a boat, comprising:
 a gimbal assembly including a support frame and enclosure configured to rotate 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 flywheel assembly, the braking system comprising:
 a first hydraulic actuator connected between the support frame and the enclosure and configured to resist precession of the flywheel assembly about the gimbal axis; 
 a main valve controlling hydraulic fluid flow in a fluid flow path to the first actuator; 
 a heat exchanger to dissipate heat generated by fluid flow through the main valve. 
   
     
     
         2 . The gyroscopic boat roll stabilizer of  claim 1 , wherein heat exchanger comprises a block having cooling passages therein to carry coolant to dissipate heat generated by fluid flow through the main valve. 
     
     
         3 . The gyroscopic boat roll stabilizer of  claim 2 , wherein the main valve forms a portion of a manifold assembly; and wherein the manifold assembly comprises the block having the cooling passages. 
     
     
         4 . The gyroscopic boat roll stabilizer of  claim 1 :
 wherein the first actuator is configured to resist precession of the flywheel assembly about the gimbal axis in a first direction;   further comprising a second hydraulic actuator connected between the support frame and the enclosure and configured to resist precession of the flywheel assembly about the gimbal axis in a second direction;   wherein the first and second actuators are configured to enable precession of the flywheel assembly about the gimbal axis in both the first and second directions;   wherein the fluid flow path fluidically connects the first and second actuators.   
     
     
         5 . The gyroscopic boat roll stabilizer of  claim 5 , wherein the main valve has first and second inputs and first and second outputs; wherein the main valve is connected to the first and second actuators by respective fluid lines that allow fluid flow between the main valve and the corresponding actuator. 
     
     
         6 . The gyroscopic boat roll stabilizer  claim 4 :
 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 main valve;   further comprising a second bypass line providing a fluid low path between first and second ends of the second fluid cylinder that bypasses the main valve.   
     
     
         7 . The gyroscopic boat roll stabilizer of  claim 6 , wherein the first bypass line allows bidirectional flow between first and second ends of the first cylinder; and wherein the second bypass line allows bidirectional flow between first and second ends of the second cylinder.