Fluid energy converter

Abstract

Embodiments include apparatus and methods of fluid energy conversion. One embodiment relates to a tube for a fluid energy converter. The tube may include a generally cylindrical and hollow body having an interior surface, an exterior surface, and a longitudinal axis. Another embodiment includes a fluid energy converter having a longitudinal axis and a rotatable tube coaxial about the longitudinal axis. In some embodiments, the rotatable tube converts kinetic energy in a fluid into rotating mechanical energy, or converts rotating mechanical energy into kinetic energy in a fluid.

1 . A fluid energy converter having a longitudinal axis comprising:
 a rotor coaxial about the longitudinal axis;   a shaft coincident with the longitudinal axis and operationally coupled to the rotor; and   a nacelle position coaxially about the longitudinal axis, wherein the nacelle is positioned inside the rotor.   
     
     
         2 . The fluid energy converter of  claim 1 , wherein the nacelle comprises a hollow body having an interior and an exterior. 
     
     
         3 . The fluid energy converter of  claim 2 , further comprising a gearbox arranged on the interior of the nacelle. 
     
     
         4 . The fluid energy converter of  claim 3 , further comprising a motor/generator arranged on the interior of the nacelle, the motor/generator coupled to the gearbox. 
     
     
         5 . The fluid energy converter of  claim 4 , further comprising a continuously variable transmission (CVT) arranged on the interior of the nacelle, the CVT coupled to the gearbox. 
     
     
         6 . The fluid energy converter of  claim 5 , wherein the CVT is coupled to the shaft, the shaft transferring an input power to the CVT. 
     
     
         7 . The fluid energy converter of  claim 5 , wherein the CVT comprises a plurality of spherical rollers configured to variably transfer power between the gearbox and the rotor based on angle of rotation of the rollers. 
     
     
         8 . A nacelle for a fluid energy converter, the nacelle comprising:
 a hollow body having an interior and an exterior; and   a plurality of helical vanes coupled to the exterior.   
     
     
         9 . The nacelle of  claim 8 , wherein the interior is configured to house a gearbox. 
     
     
         10 . The nacelle of  claim 9 , wherein the interior is configured to house a generator. 
     
     
         11 . The nacelle of  claim 10 , wherein the interior is configured to house a continuously variable transmission (CVT). 
     
     
         12 . The nacelle of  claim 11 , wherein the CVT is coupled to the gearbox. 
     
     
         13 . The nacelle of  claim 12 , wherein the CVT is coupled to the generator. 
     
     
         14 . The nacelle of  claim 11 , wherein the CVT is a ball-type transmission. 
     
     
         15 . A method of operating a fluid energy converter, the method comprising the steps of:
 providing a rotor;   mounting a nacelle on the interior of the rotor, the nacelle having a hollow body with an interior and an exterior surface;   mounting the rotor such that a longitudinal axis of the rotor is substantially parallel to a fluid stream; and   pitching and/or yawing the rotor relative to the flow direction of the fluid stream.   
     
     
         16 . The method of  claim 15 , further comprising the step of mounting a gearbox on the interior of the nacelle. 
     
     
         17 . The method of  claim 16 , further comprising the step of coupling a continuously variable transmission (CVT) to the gearbox, the CVT arranged on the interior of the nacelle. 
     
     
         18 . The method of  claim 17 , further comprising the step of coupling a motor/generator to the CVT, the motor/generator arranged on the interior of the nacelle. 
     
     
         19 . The method of  claim 18 , further comprising the step of adjusting a ratio of the CVT to maintain a constant input speed to the motor/generator. 
     
     
         20 . The method of  claim 18 , wherein adjusting the ratio of the CVT comprises the step of tilting a plurality of spherical power adjusters.