Drivetrain for a Wave Energy Converter

Abstract

An apparatus, system, and method are disclosed for WEC system for a wave energy converter. The system includes a buoyant object, a reaction bity and a line coupling the reaction body and the buoyant object. The system further includes a drivetrain coupled to one of the buoyant object or reaction body. The drivetrain includes a sheave coupled to one of the buoyant object or reaction body and an actuator coupled to the sheave. The line is coupled to the sheave, wherein movement of the buoyant object relative to the reaction body applies a force to the sheave. The force on the sheave drives the actuator, wherein the actuator is configured to apply a spring force.

What is claimed is: 
     
         1 . A wave energy converter system, comprising:
 a buoyant object;   a reaction body coupled to the buoyant object by one or more lines;   one or more drivetrains coupled to one of the buoyant object or reaction body, wherein the one or more drivetrains comprise:
 a sheave coupled to one of the buoyant object or reaction body, wherein the one or more lines are coupled to the sheave, wherein movement of the buoyant object relative to the reaction body applies a force to the sheave. 
   
     
     
         2 . The system of  claim 1 , wherein the force on the sheave drives a hydraulic actuator, coupled with an accumulator that is configured to provide a spring force. 
     
     
         3 . The system of  claim 1 , wherein the force on the sheave drives a hydraulic motor/pump that is configured to provide a damping force. 
     
     
         4 . The system of  claim 1 , wherein the force on the sheave drives a hydraulic actuator that is configured to provide both damping and spring forces. 
     
     
         5 . The system of  claim 1  wherein the force on the sheave drives an electrical generator that is configured to provide a damping force. 
     
     
         6 . The system of  claim 2 , further comprising a gearbox coupled between the sheave and the actuator. 
     
     
         7 . The system of  claim 3 , further comprising a gearbox coupled between the sheave and the hydraulic motor/pump. 
     
     
         8 . The system of  claim 1 , wherein the sheave is a winding mechanism configured to wind the line. 
     
     
         9 . The system of  claim 2 , wherein the rate of spring force can be changed through a selectable gas volume attached to the accumulator connected to the output of the actuator. 
     
     
         10 . The system of  claim 1 , wherein relative motion of the buoyant object and the reaction body applies a rotational force to the sheave. 
     
     
         11 . The system of  claim 1 , wherein the sheave is configured to oscillate around a mean position. 
     
     
         12 . The system of  claim 1 , wherein the damping force is provided by a mechanical pump. 
     
     
         13 . A drivetrain for a wave energy converter, comprising:
 a sheave coupled to a buoyant object, wherein the buoyant object is coupled to a reaction body by one or more lines, wherein the line is coupled to the sheave, wherein movement of the buoyant object relative to the reaction body applies a force to the sheave.   
     
     
         14 . The drivetrain of  claim 13  wherein the force on the sheave drives a hydraulic actuator which is configured to apply a spring force. 
     
     
         15 . The system of  claim 13 , wherein the force on the sheave drives a hydraulic actuator that is configured to provide a damping. 
     
     
         16 . The system of  claim 13 , wherein the force on the sheave drives a hydraulic actuator that is configured to provide both damping and spring forces. 
     
     
         17 . The system of  claim 13  wherein the force on the sheave drives an electrical generator that is configured to provide a damping force. 
     
     
         18 . The system of  claim 17 , further comprising a gearbox coupled between the sheave and the generator. 
     
     
         19 . The drivetrain of  claim 14 , wherein the sheave is a winding mechanism configured to wind the line. 
     
     
         20 . A wave energy converter system, comprising:
 a buoyant object, wherein the buoyant object is a surface float;   a reaction body coupled to the buoyant object by two or more lines and the lines are flexible;   a drivetrain coupled to one of the buoyant object or reaction body, wherein the drivetrain comprises:
 a sheave coupled to one of the buoyant object or reaction body, wherein two or more lines are coupled to the sheave, wherein movement of the buoyant object relative to the reaction body applies a force to the sheave; 
 an actuator coupled to the sheave, wherein the force on the sheave drives the actuator, wherein the actuator is configured to apply a spring force; and 
   a generator, wherein the sheave is configured to drive the generator.