Novel Electrical Generators For Use In Unmoored Buoys And the Like Platforms With Low-Frequency and Time-Varying Oscillatory Motions

Abstract

A buoy for generating electrical energy from an roll/pitch motion resulting from a passing wave. The buoy including: a body; a pendulum member rotatably disposed on the body at a first end of the pendulum member; a pendulum mass disposed at a second end of the pendulum member; an exciter mass positioned on the pendulum member between the first and second ends; and one or more generators for generating electrical energy, the one or more generators being positioned in the body such that swinging of the pendulum member due to the roll/pitch motion causes a portion of the exciter mass to engage the one or more generators to generate the electrical energy.

What is claimed is: 
     
         1 . A buoy for generating electrical energy from an roll/pitch motion resulting from a passing wave, the buoy comprising:
 a body;   a pendulum member rotatably disposed on the body at a first end of the pendulum member;   a pendulum mass disposed at a second end of the pendulum member;   an exciter mass positioned on the pendulum member between the first and second ends; and   one or more generators for generating electrical energy, the one or more generators being positioned in the body such that swinging of the pendulum member due to the roll/pitch motion causes a portion of the exciter mass to engage the one or more generators to generate the electrical energy.   
     
     
         2 . The buoy of  claim 1 , wherein the exciter mass has tips for engaging the one or more generators when the pendulum member swings in first and second directions. 
     
     
         3 . The buoy of  claim 1 , wherein the pendulum mass is releasably retained against a surface of the body and released by the roll/pitch motion. 
     
     
         4 . The buoy of  claim 1 , wherein the exciter mass is separate from the pendulum mass. 
     
     
         5 . The buoy of  claim 1 , wherein the one or more generators are piezoelectric generators. 
     
     
         6 . The buoy of  claim 1 , wherein the body has a cross-section such that it is stabile in a rotation direction. 
     
     
         7 . The buoy of  claim 1 , wherein the body has one or more fins so as to be stabile in a rotation direction. 
     
     
         8 . A method for generating electrical energy from an roll/pitch motion resulting from a passing wave, the method comprising:
 rotatably disposing a pendulum member on a body of a buoy at a first end of the pendulum member;   disposing a pendulum mass at a second end of the pendulum member;   positioning an exciter mass on the pendulum member between the first and second ends; and   generating electrical energy resulting from a swinging of the pendulum member due to the roll/pitch motion by causing a portion of the exciter mass to engage at least one generator to generate the electrical energy.   
     
     
         9 . The method of  claim 8 , further comprising offsetting the pendulum mass such that the body of the buoy is heeled to one side when floating in water. 
     
     
         10 . The method of  claim 9 , wherein the wherein the offsetting comprises releasably retaining the pendulum mass against a surface of the body. 
     
     
         11 . The method of  claim 10 , wherein the pendulum mass is released from the surface of the body by the roll/pitch motion to cause the exciter mass to engage the at least one generator to generate the electrical energy. 
     
     
         12 . The method of  claim 11 , wherein, after the release of the pendulum mass from the surface, the pendulum mass is releasably retained on another surface of the body. 
     
     
         13 . The method of  claim 12 , wherein the pendulum mass is released from the another surface of the body by the roll/pitch motion to cause the exciter mass to again engage the at least one generator to generate the electrical energy.