Patent Publication Number: US-2009236858-A1

Title: Vertical turbine for water or wind power generation

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 USC 119(e) of U.S. Provisional Application Ser. No. 61/038,628, filed Mar. 21, 2008, the contents of which are incorporated herein by reference. 
    
    
     BACKGROUND OF INVENTION 
     This application relates generally to ocean current, tidal or wind power generation. More specifically, this application relates to a vertical turbine with movable blades or sails for harnessing the kinetic energy of a moving fluid and converting it into useful electrical energy. 
     SUMMARY 
     Conventional turbine systems for harnessing kinetic energy of moving fluids, such as wind or water, and converting that kinetic energy into electrical energy, are well known, generally comprising fixed blade turbines, limiting the range over which the blade provides power to the system, the placement of the turbine system in the fluid stream, and the type of fluid stream the system can be utilized in. The present invention is a vertical turbine system having blades or sails which are pivotable about an axis formed by their leading edge as the turbine rotates about its shaft. These pivoting blades or sails allow them to provide power over a larger portion of the circumference of the turbine as it rotates, allow the turbine to develop power no matter what direction the flow of fluid through it is, and enable the system to function is water or air. Described herein is a vertical turbine system for generating power from a fluid stream that is easy to use and solves the problems mentioned above. The device is of simple construction, inexpensive to produce, economical to maintain, and can be used in conjunction with all forms of electrical systems. 
     In particular, this application discloses a vertical turbine system employing a turbine having a vertical rotational shaft with upper end lower ends, a pair of oppositely disposed circular frame members radially affixed to the shaft, rectangular vanes having a pair of distal ends, a leading edge and a trailing edge, with each vane rotatably affixed to the circular frame members at the ends of their leading edge, and means for limiting rotation of the vanes to a maximum of about 40° to about 80°. The vertical turbine system of the present invention also has a generator operatively connected to one end of the shaft for converting rotational energy of the shaft into electrical energy, anchoring means for affixing the lower end of the shaft to a ground surface, and torque control means for maintaining the generator in a generally stationary position as the turbine rotates about the shaft. 
     This application also discloses a vertical turbine system employing a turbine having a vertical rotational shaft with upper end lower ends, a pair of oppositely disposed circular frame members radially affixed to the shaft, rectangular sails having a pair of distal ends, a leading edge and a trailing edge, each sail rotatably affixed to the circular frame members at the ends of its leading edge, and a tether connecting the trailing edge of each end of the sails to one of the circular frame members for limiting rotation of the sails to a maximum of about 40° to about 80°. The vertical turbine system of the present invention also has: anchoring means for affixing the lower end of the shaft to a ground surface, the anchoring means including a cylindrical bore through the center of the shaft, a vertical support pole securable to a terrestrial ground surface, the vertical support pole sized to fit within the cylindrical bore, and bearing means for allowing free rotation of the shaft about the vertical support pole; a generator affixed to the vertical support pole; a ring gear affixed to the lower end of the shaft; and a drive gear integral to the generator, the drive gear sized to matingly engage the ring gear to transmit rotational energy of the shaft to the generator for converting rotational energy of the shaft into electrical energy. 
     This application further a method of generating electrical energy from a moving fluid stream comprising the steps: providing a vertical turbine system including a turbine having a vertical rotational shaft with upper and lower ends, a pair of oppositely disposed circular frame members radially affixed to the shaft, generally rectangular vanes having a pair of distal ends, a leading edge and a trailing edge, each vane rotatably affixed to the circular frame members at the ends of its leading edge, and means for limiting rotation of the vanes to a maximum of about 60°, a generator operatively connected to one end of the shaft for converting rotational energy of the shaft into electrical energy, anchoring means for affixing the lower end of the shaft to a ground surface, and torque control means for maintaining the generator in a generally stationary position as the turbine rotates about the shaft; and anchoring the vertical turbine system to a ground surface with the turbine in a moving fluid stream such that the moving fluid stream causes the turbine to rotate about the shaft. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings, when considered in connection with the following description, are presented for the purpose of facilitating an understanding of the subject matter sought to be protected. 
         FIG. 1  is a cross-sectional top view and side view of a first embodiment of a vertical turbine system disclosed herein; 
         FIG. 2  is a top cross-sectional view of a turbine disclosed herein; 
         FIG. 3  is a cross-sectional view of a second embodiment of a vertical turbine system disclosed herein; 
         FIG. 4  is a cross-sectional top and side views of a third embodiment of a vertical turbine system disclosed herein; 
         FIG. 5  is a perspective view of a flexible sail disclosed herein; and 
         FIG. 6  is a perspective view of a turbine disclosed herein. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , shown is a cross-sectional view of the vertical turbine system  10  of the present invention. The vertical turbine system  10  includes a turbine  12 , a generator  14  connected with the turbine  12  for converting rotational energy of the turbine  12  into electrical energy, anchoring means for affixing the vertical turbine system  10  to a ground surface, and torque control means for maintaining the generator  14  in a stationary position as the turbine  12  rotates. The turbine  12  rotates about a vertical rotational shaft  20  having an upper end  22  and a lower end  24 , and includes a pair of oppositely disposed circular frame members  26  radially affixed to the shaft  20 , a number of generally rectangular vanes  28 , each having a pair of distal ends  30 , a leading edge  32  and a trailing edge  34 , with the vanes  28  rotatably affixed to the circular frame members  26  at the ends  30  of their leading edge  32 , and means for limiting rotation of the vanes  28  to a maximum of about 40° to about 80°. The amount that rotation is limited may be fixed or variable by the user. The vanes  28  use the force imparted from the moving fluid to generate mechanical rotating power that is transmitted through the vanes  28  to the frame members  26 , then to the shaft  20 , and from the shaft  20  to the generator  14 . The angle of attack of the vanes  28  changes to take best advantage of the fluid motion as the turbine  12  rotates. The generator  14  can be operatively connected to one of the upper end  22  and the lower end  24  of the shaft  20 , either directly or through a reduction gear. The shaft  20  can be rigid or flexible, and multiple turbines  12  can share a common shaft  20 . 
       FIG. 1  illustrates an embodiment of the present invention adapted for marine use further including a buoyancy device  38  affixed thereto, one or more anchors  40  as the anchoring means for affixing the lower end  24  of the shaft  20  to an underwater ground surface; and a water-resistant housing  42  surrounding the generator  14 . The buoyancy device  38  maintains buoyancy of the entire vertical turbine system  10 , and controls the level of the system relative to the water surface. The generator  14  is shown connected to the upper end  22  of the shaft  20  to facilitate maintenance and surface collection of generated electrical energy. For underwater collection, the generator  14  could be connected to the lower end  24  of the shaft  20 . The generator  14  can be an AC or DC electric generator, with necessary equipment for electricity generation, conditioning and transmission to a fixed station or ship through a suitable power cable. 
     For marine use, the generator  14  must be held relatively stationary in the current as the turbine  12  is rotated thereby. A member  48  extending horizontally from the generator housing  42  is shown as such torque control means, maintaining the generator housing  42  in a fixed position relative to the current, and stops the torque from the shaft  20  and generator  14  from being transferred to the generator housing  42 , preventing the generator housing  42  from spinning. 
     Shown in the top view of  FIG. 1  is an embodiment of the vanes as rigid blades  44  which can be flat or, for higher efficiency, curved into an airfoil-shaped profile. The blades  44  pivot about their leading edge  32  as an axis, so that a minimal cross-section is presented when moving against the current. In order to present a maximal cross-section when moving with the current, the rotation of the blades  44  about their leading edge  32  is limited to a range of about 40° to about 80°, or about 50° to about 70°, or about 60°. For this, rotation of the blades  44  can be blocked by mechanical stops  46 . 
     Referring now to  FIG. 2  and  FIG. 3 , illustrated are embodiments of the invention wherein the vanes are flexible sails  50 .  FIG. 2  shows a cross-sectional top view of the turbine having a plurality of flexible sails  50  affixed to the circular frame members  26  along their leading edges  32 . As the turbine rotates, the sails  50  pivot about their leading edge  32  as an axis, moving through an arc at their trailing edge  34 , so that the sails  50  tack or jibe relative to the fluid flow direction as the turbine is rotated by the current. The movement of the trailing edge  34  of the sail  50  is limited by a tether  52 . The flexible sails  50  can be stiffened by the addition of stiffening means  54  extending generally horizontally between the leading edge  32  and the trailing edge  34  of the sail  50 . 
     As shown in  FIG. 3 , the stiffening means for the sails  50  can be horizontally affixed slats  56 . Tethers  52  are shown connecting the trailing edge  34  on distal ends  30  of the sails  50  to the circular frame members  26 . Tethers can also be used to affix the leading edge  32  of the sails  50  to the circular frame members  26 . Tension between the anchoring means and the buoyancy device maintains the separation of the circular frame members  26  and tension on the ends  30  of the sails  50 . 
     Referring now to  FIG. 4 , illustrated is an embodiment of the vertical turbine system  10  of the present invention adapted to land use, wherein the anchoring means includes a cylindrical bore  58  running through the center of the shaft  20 , a vertical support pole  60  which is secured to the ground, with the vertical support pole  60  sized to fit within said cylindrical bore  58 . The generator  14  is affixed to the lower end  24  of the shaft  20 , with its attachment to the vertical support pole  60  acting to maintain the generator  14  in a stationary position as the turbine  12  rotates. Bearing means  62  allow for free rotation of the shaft  20  about the vertical support pole  60 . The weight of the circular frame members  26  and the shaft  20  maintain downward tension on the sails  50 . 
     Illustrated in  FIG. 5  is an embodiment of the invention wherein a ring gear  64  is affixed around the lower end  24  of the shaft  20  and matingly engages a drive gear  66  integral to the generator  14 , to transmit rotational energy of the shaft  20  to the generator  14 . The ring gear  64  increases the speed of the drive gear  66  rotation speed relative to the turbine rotational speed. Also shown is an embodiment of the bearing means having an upper split bearing assembly  68  affixed to an upper portion  70  of the vertical support pole  60  and a lower split bearing assembly  72  affixed to a lower portion  74  of the vertical support pole  60 , to provide rolling engagement between the shaft  20  and the vertical support pole  60 . The split bearing assemblies are affixed, for example bolted or screwed, to the vertical support pole  60  and are sized to fit within the cylindrical bore  58  of the shaft  20 . A thrust bearing  76 , can be affixed to the upper end  22  of the shaft  20  within the cylindrical bore  58  to contact the upper split bearing assembly  68  and support the weight of the turbine on the vertical support pole  60  with rolling engagement, allowing free rotation of the turbine about the vertical support pole  60 . 
     Referring now to  FIG. 6 , shown is an embodiment the turbine  12  wherein a plurality of vertical rods  78  interconnect the circular frame members  26  and form the leading edges  32  of the flexible sails  50 . 
     The vertical turbine system of the present invention, when used in marine environments, may be used for power generation from tidal currents, which flow in two directions, with varying velocities. Alternately, the vertical turbine system may be used for stable ocean currents, such as those between islands, or the Gulf Stream. Smaller models may be used in tidal flows to generate auxiliary power for moored vessels. The vertical ocean turbine may be used to develop power for a wide variety of equipment, including electric power generation. Single or multiple vertical ocean turbines may be mounted on a single flexible shaft to an electric generator near the surface, with a buoyancy device holding the unit near the surface, and an anchor holding the turbine in place and maintaining the vertical configuration. This would allow a ship to assemble and deploy multiple turbine sections vertically, with one generator. 
     The vertical turbine system of the present invention, when used with wind on land, may be used for small to large power generation applications, including wind power farms, commercial applications, residential housing applications or roadway lighting applications. 
     While the present disclosure has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this disclosure is not limited to the disclosed embodiments, but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.