Abstract:
A buoyant hydro turbine( 31 ) for capturing and utilizing energy in the currents of flowing water. A driven component( 33 ) produces electricity or other energy is coupled to and supported by a buoyant rotor( 64 ), increasing efficiency and eliminating the need for an independent supporting structure. Tethered in flowing water, the current( 71 ) rotates the rotors( 32 ) and transfers rotatable energy to the central driven component( 33 ) where electricity or other mechanical work is produced. A number of embodiments are adapted for optimizing and maintaining positioning in a stream of moving water. Additional embodiments optimizing the efficiency and effectiveness of the turbine in capturing and utilizing the current&#39;s kinetic energy as well as hydrostatic pressure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     Not Applicable 
     FEDERALLY SPONSORED RESEARCH  
     Not Applicable 
     SEQUENCE LISTING OR PROGRAM  
     Not Applicable 
     BACKGROUND 
     1. Field 
     The invention relates to buoyant water powered device for producing electricity or other mechanical work in areas of flowing water. 
     2. Information 
     This invention relates to a device that is designed to capture energy from existing currents of water and is particularly designed to operate while floating in-stream. 
     One of this planet&#39;s most common and readily available source of renewable energy is moving water. The power of Hydro kinetic energy is well known and well documented. It is abundant and is found in the vast quantities in every stream, river or other moving bodies of water. Its use and utilization is a function of economic and ecological constraints. 
     The most familiar methods for the utilization of this energy require dams, impounds or major civil works to contain and redirect the current. Making those methods inappropriate, or impractical for the majority, if not substantially all existing currents, for economic and ecological reasons. Therefore if this vast resource is to be accessed effectively and efficiently, existing currents must be utilized, while minimizing environmental and economic impacts. 
     A more economical and environmentally sensitive means for utilizing and capturing kinetic energy from existing currents are generally called free flow or in-stream hydropower. In many instances these in-stream devices require physical support from a structure, which is placed or attached to the river or stream&#39;s bed, or bank. This increases costs, perhaps disrupting navigation and the environment. Therefore are not viable options in many locations. 
     It is, therefore, a principal objective of this invention to substantially eliminate the need for the construction of any such civil works by positioning the device on the surface without fixed support structures. By floating, the invention substantially eliminates the need for such structures. 
     In other instances the water powered device is positioned in the current, through placement or attachment to a floating component, to provide support. These separate floating components add cost, complexity, and inefficiency. Because these floating components are subjected to the forces of the current they must effectively resist and dissipate that kinetic energy to remain in the desired position. 
     It is another object of this device to increase efficiency and effectiveness of converting the current&#39;s kinetic energy into usable power by integrating the required buoyancy into the device. Therefore reducing drag on the device, increasing its efficiency, and increasing the kinetic energy available to the turbine. Some of these floating water powered devices, integrate a floating component into the device. This too increases drag upon the device reducing efficiency. 
     Therefore it is another objective of the device to integrate the required buoyancy into the functional parts of the device to reduce drag and increase efficiency. 
     Many water-powered devices have employed propellers or water wheels that are substantially fully submerged in the water. Such devices must be positioned with their axis of rotation extending parallel to the direction of flow of the water. This is not a viable alternative in many circumstances. Requiring more depth of the current, and involving navigational and environmental concerns with debris and aquatic life providing a risk to the device and aquatic life alike. 
     It is a further objective of this invention to provide a buoyant water powered device that will not require to be completely submerged within the water. 
     All in-stream water powered devices must be held in a fixed position in the current to operate. In many cases theses devices may have multiple connections serving individual or multiple functions. Each additional connection requires additional effort to construct, install and maintain. Each additional connection increases the risk of entanglement with debris and aquatic life. 
     It is, therefore, a still further objective of this invention to provide an improved tether that can integrate multiple functionality with support for positioning the device, in an integrated single tether, serving as a single point of physical connection. 
     For maximum efficiency and water powered device must maintain its position relative to the current. In many alternatives this may include a support structure, or in the case of floating devices rudders, vanes and other single purpose additions. 
     It is another objective of this device to integrate features that maintained its position was so that the turbine&#39;s rotation is about an axis that is perpendicular to the current. These features will additionally contribute to the turbine&#39;s efficiency, debris avoidance and structural functionally. 
     In most in-stream surface based water powered devices are based upon the undershot water wheel and limited to hydro-kinetic energy of the current. 
     It is another objective of this device to create hydro static pressure and utilize it in addition to the current&#39;s hydro-kinetic energy, by the positioning of turbine, blades and the integration of the other parts. 
     3. Prior Art 
     By their nature, water powered devices must be positioned relative to the resource upon which they rely. Many are located or fixed to a permanent support structure such as a dam, pier, or foundation. Others are mounted to the ground or the bottom of the stream or river bed. One subset of water powered devices maintains their desired position by floating on the surface of the current or water source. This subset of floating surface-mounted, water powered devices encompass those devices that are attached to or mounted upon flotation components that contribute little or no functional value to the water-powered device, aside from providing support. Another set of floating water-powered devices integrate the flotation component into the device itself as, in the case of the device described in U.S Pat. No. 4,872,805. These articulated buoyant members contribute drag on the device, and do not contribute to the device&#39;s efficiency in capturing the kinetic energy delivered to the water powered device. 
     Some devices such as in another embodiment of U.S. Pat. No. 4,872,805 use the hydro dynamic force of the current to assist in maintaining the device&#39;s position, relative to the surface of the water. This too, fails to effectively utilize efficiently the Hydro kinetic energy placed upon, and delivered to, the device. 
     Another type of floating water powered device as disclosed in U.S. Pat. No. 7,042,113, a generator is placed in the drum that is rotated by moving water. This device requires multiple attachments to both sides of the drum at its axes and is affixed to a permanent structure. The placement of the generator within the drum of the water wheel, limits the flexibility of adjusting the device for various current conditions, and requires multiple attachments that increase the device&#39;s risk of damage or entanglement in debris. This is why the invention attaches the tether to a single point on the driven component at the midpoint of the rotor. 
     Existing buoyant or floating water powered devices such as water wheels or turbines, are of a type called undershot water wheels. These devices use the principle of impulse power in which only the kinetic power, or the strength of the current, is utilized. This invention the subject of this patent utilizes not only impulse power but also hydrostatic pressure. Hydrostatic pressure has been utilized with fixed rotary hydraulic pressure machines, with dams or other form of water retention. Hydrostatic Pressure results from higher water surface levels upstream to the turbine versus downstream. Because of this invention&#39;s distribution of buoyancy to the rotor, it allows for maximum force to develop over its&#39; entire width of the turbine enabling a disparity in water level between the upstream and downstream side of the turbine. The invention&#39;s implementation of a single rotor with the major points of dissipation of the current&#39;s excess kinetic energy is limited to the rotor ends increasing the disparity of the water level and pressure between the upstream and downstream sides of the rotor. The rotor does have a gap for the attachment of the tether to the driven component, but it is or minimized size and with a ridge extending through the gap, the effect is effectively eliminated. 
     SUMMARY 
     This invention and associated embodiments pertain to a buoyant in-stream turbine. One embodiment of the invention comprises a buoyant rotor substantially enclosing a driven component and support component. In use, the device is placed in a body of moving water and held in desired location within the water by a tether. The tether has the means for transporting energy, materials or communications individually or in combination to and from the device and its anchorage. The moving water impacts the invention with kinetic energy and in turn, the build-up of hydrostatic pressure. This combination exerts force on the rotor&#39;s blades causing it to rotate. The rotational energy of the rotor is then transferred to the driven components, where it is utilized to create electricity or some other form of mechanical energy. The driven component is encircled by a ridge, which reduces the risk of entanglement with debris, serves as a vane in the water&#39;s current to maintain the turbines position perpendicular to the direction of the current, and in turn, increases the available hydrostatic pressure. 
     DRAWINGS 
     Figures 
       FIG. 1  is a perspective view showing water powered device constructed in accordance with this invention as placed in a current of water. 
       FIG. 2  is a perspective view of the device shown in  FIG. 1 . 
       FIG. 3   a  is a perspective view of the an embodiment of the device 
       FIG. 3   b  is a partially exploded view showing the association of the device components. 
       FIG. 3   c  is a side elevation view of the embodiment 
       FIG. 4   a  is a perspective view of another embodiment of the device 
       FIG. 4   b.  is a partially exploded view showing the association of the device components. 
       FIG. 4   c.  is a cross-sectional perspective view of the device. 
       FIG. 4   d  is a side elevation view of the embodiment 
       FIG. 5   a  is an exploded perspective view of another embodiment of the device and driven component 
       FIG. 5   b  is a cross-sectional perspective view of the embodiment of  FIG. 5   a    
       FIG. 6   a  is an exploded perspective view of another embodiment of the device 
       FIG. 6   b  is a cross-sectional perspective view of the embodiment in  FIG. 6   a    
       FIG. 6   c  is an exploded perspective view of the embodiment in  FIG. 6   b    
       FIG. 6   d  is a cross-sectional perspective view of the exploded perspective view in  FIG. 6   c    
       FIG. 7   a  is an exploded perspective view of another embodiment of the device 
       FIG. 7   b  is a cross-sectional perspective view of the embodiment in  FIG. 7   a    
       FIG. 7   c  is an exploded perspective view of the embodiment in  FIG. 7   b    
       FIG. 7   d  is a cross-sectional perspective view of the exploded perspective view in  FIG. 7   c    
       FIG. 8   a, b, c, d  is a perspective view of several embodiments of the tether 
       FIG. 9  is a perspective view of another embodiment of the device 
       FIG. 10  is a top plan view of the embodiments of  FIG. 9   
       FIG. 11  is a perspective view of another embodiment of the invention 
       FIG. 12  is a side elevation view of the embodiment of  FIG. 11   
       FIG. 13  is a perspective view of another embodiment of the invention 
       FIG. 14  is a side elevation view of the embodiment of  FIG. 13   
       FIG. 15  is a perspective view of another embodiment of the invention 
       FIG. 16  is a side elevation view of the embodiment of  FIG. 15   
       FIG. 17  is a perspective view of another embodiment of the invention 
       FIG. 18  is a side elevation view of the buyer embodiment of  FIG. 17   
       FIG. 19  is a top plan view cross-sectional taken through the axis of the invention of an embodiment 
       FIG. 20  is a top plan view of the cross-sectional taken through the axis of the invention and displaying another embodiment of the invention along the lines of  FIG. 19   
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. 
     The present invention is a buoyant turbine for generating power from water currents. In  FIG. 1 , a perspective view of the first embodiment of the present invention identified by reference numeral  31 , is shown in a current in a body of water, such as a stream, river, or tidal flow identified by reference numeral  72 . The current flows in the direction of the arrow  71 . The invention  31 , includes a water driven rotor  32 , which drives the Driven Component, indicated generally by the reference numeral  33  and which may comprise an electrical generator or other means of transforming the rotational energy from the rotor into mechanical energy, upon the water current  71  through the rotors  32 , in a manner to be described. The assembly consisting of the rotor  32  and the driven component  33  about an axis indicated generally by the reference number  11 . In  FIG. 1 , the device  31  is positioned in the current  72  by means of tether assembly indicated generally by the reference number  21 . The tether  21  is in turn attached to an anchorage  75 . 
     In  FIG. 1  the operation of this embodiment will now be described. The device  31  is placed in a body of water  73  with a current  71 . The device  31  is held in its relative position in the current  71  by a tether  21  attached to an anchorage  75 , and in turn attached to driven component  33 . The device  31  maintains a relative position to the surface of the water  72  substantially from the buoyancy provided by rotor  32 . The device&#39;s  31  position relative to the surface of the water  72  is to maximize the usable energy available to device  31 , while minimizing un-usable kinetic energy or drag on the device  31 . The current  71  will create hydrodynamic forces causing the rotor  32  to rotate about the axis  11 . The device  31  has the means to transfer the resulting rotatable energy from the rotor  32  to the driven component  33 . The driven component will use utilize the rotatable energy to create electricity or some other form of mechanical work. 
     In  FIG. 2  an embodiment of the invention, the rotor  32  comprises a hub  64  of cylindrical shape and providing substantially all of the required buoyancy for supporting the invention. The rotor has a plurality of blades  61  attached to the radial surface  62  of the hub  64 . The rotor  32  comprises a means of coupling to the driven component  33 , extending perpendicular to the current  71  and rotating around the device axis  11 . The rotor  32  substantially encloses the driven component  33 , substantially eliminating any kinetic energy from being placed on the driven component  33  by the current  71 . 
     As viewed in  FIG. 3   a ,  3   b ,  3   c , this embodiment of the driven component  33  is smaller in diameter and in depth than the cavity  65  in the rotor&#39;s  32  hub  64 . The driven component  33  is substantially nested in the cavity  65 , in the rotor&#39;s  32  hub  64 , substantially encasing the drive component  33  within the cavity  65  in hub  64 . In this embodiment the rotor  32  is coupled with the driven component  33  and rotates about an axis  11 . The rotor  32  transfers rotatable energy to driven component  33  where it is utilized to produce electricity or some other form of energy. 
     As viewed in  FIG. 3   a ,  3   b ,  3   c , in this embodiment of the invention there is a single connection to the invention. The tether  21  attaches to the driven component  33 . In turn the tether  21  is attached to anchorage  75 . The tether  21  comprises the point of connection  23  to the driven component  33 . A component of the tether  21  is a rigid components  22  extending from the point of connection  23  for a length before connecting to the tether cable  24 . This ridged portion  22 , reduces the risk of entanglement with rotatable portions of the invention, specifically the rotor  32  and its blades  61 . 
     In  FIG. 4   a ,  4   b ,  4   c ,  4   d  an additional embodiment of this invention, the drive component  33  comprises an encircling ridge positioned parallel to the current  71 . The ridge  34  has a face  44  with a height that enables the ridge perimeter edge  41 , to be substantially equal or greater than the rotational diameter of the rotor  32 , including the rotor&#39;s hub  64  and Blades  61 . The ridge  34  reduces the risk of fouling the device  31  with aquatic debris that might become entangled, wedged between the rotatable portions of the device  31 , such as the rotor  32  and the non-rotatable portions components including the driven component  33 , the ridge  34  and the tether  21 . The ridge  34  acts as a vane in the current  71  and maintains the rotor  32  position perpendicular to the current  71 . The ridge  34  also increases the Hydrostatic energy by decreasing the water level  72  on the downstream side of the device  31 , relative to the water level upstream from the invention. 
     In  FIG. 6   a ,  6   b  this embodiment the driven component  33  is larger in diameter than the rotor&#39;s  32  hub  64 . A portion of the driven component&#39;s  33  cylindrical face  42  is external to the rotor  32  hub  64 . The rotor&#39;s  32  blades  61  are notched  67  to accommodate the portion of driven component  33 , which extrudes beyond the hub&#39;s  64  inside cylindrical perimeter  66 . The rotor&#39;s  32  blades  61  substantially encase the driven component  33 . 
     As viewed in  FIG. 7   a ,  7   b ,  7   c ,  7   d , this embodiment the driven component  33  encircles the rotor  32  hub  64 . The driven component  33  has an opening  81  in which the rotor  32  hub  64  is positioned. The driven component  33  is positioned approximately midway on the length of hub  64  so that approximately half of the rotor  32  extends on each side of driven component  33 . The tether  21  is attached to driven component  33 . 
     In  FIG. 7   b  the embodiment&#39;s tether  21  serves as the only physical connection to the invention. The tether  21  attaches to the driven component  33  at  23 , which is connected to rigid portion  22 . The rigid component  22  reduces the risk of entanglement of the tether  21  with the invention&#39;s rotatable parts, the rotor  32  and its blades  61 . 
     In  FIG. 7   c ,  7   d  of this embodiment, the rotatable component of the invention, which is the rotor  32 , is shown in an exploded and cross-sectional exploded view, separated from the non-rotatable component including the driven component  33  and the attached tether  21 . 
     In  FIG. 8   a ,  8   b ,  8   c ,  8   d  an additional embodiment to the embodiment discussed and demonstrated in  FIG. 7   a,b,c,d  of this invention the drive components  33  comprises an encircling ridge  34 , positioned parallel to the current  71 . The ridge  34  has a face  44 , with a height is such that the ridge perimeter edge  41 , is substantially equal or greater than rotatable diameter of the rotor  32 , including the rotor hub  64  and Blades  61 . The ridge  34  reduces the risk of fouling the device  31  with aquatic debris that might become entangled, wedged between the rotatable portions of the device  31 , such as the rotor  32  and the non-rotatable portions components including the driven component  33 , the ridge  34 , and the tether  21 . The ridge  34  acts as a vane in the current  71  and maintains the rotor  32  position perpendicular to the current  71 . The ridge  34  also increases the Hydrostatic energy by decreasing the water level on the downstream side of the rotor  32  relative to the upstream water. 
     In  FIG. 10   a,b,c,d  another embodiment of the invention the tether, incorporates the means for transport items such as materials, energy or communication to and from the invention. To accomplish this the tether, may comprise multiple functions. In  FIG. 10   a  embodiment of the tether incorporates a coaxial cable  95  for the transport of electricity or communications to and from the invention and the anchorage. Steel strength cables  93  surround the coaxial cable  95 , providing the strength required to position the invention in the current. These cables are finally wrapped in a buffer tube  92  and an outer jacket  91 . The  FIG. 10   b  embodiment of the tether incorporates a hose  97  for transporting fluids such as air or water under pressure to and from the invention. This hose  97  is incorporated within the steel strength cables  93  encased in a buffer tube  92  and an outer jacket  91 . The embodiment of the tether demonstrated in  FIG. 10   c  comprise multiple electrical cables  95  providing a positive, negative a ground cable, incorporated within the steel strength cables  93  encased in a buffer tube  92  and an outer jacket  91 .  FIG. 10   d  embodiment suggests the ability of multiple functions by combining the electrical functionality of  FIG. 10   c  with an Optical fiber  94  provide communication ability with the invention. 
     As viewed in  FIG. 15 ,  16  this embodiment of invention, the rotor  32  has a disc  67  attached to or incorporating the ends of the hub, which is furthest away from the driven component  33 . This disc  67  is parallel to the current  71 . The disc  67  has a diameter substantially equal or greater than that of rotor  32  including the rotor hub and blades  61 . Disc  67  reduces the risk of fouling from aquatic debris that may become entangled, or wedged in Blade  61 . Blades  61  may or may not be attached to disc  67 , if attached to the disc  67  they may provide additional structural strength and support. Disc  67  will provide additional protection to Blades  61  and hub  64  from aquatic debris. Disc  67  will also act as a vane in current  71 , helping to maintain the invention&#39;s position to the current  71 . 
     In  FIG. 17 ,  18  this embodiment of the invention, the rotor  32  blades  61   b  contain a concave side on the portion of the blade facing the current  71 . The concave shape of Blades  61   b  will increase the efficiency at which Hydro kinetic energy is captured from the current  71 , and increases the force on said Blades  61   b  exerting greater torque on rotors  32  hub  64  increasing rotational speed and torque. The concave shapes of blades  61   b  also increase the hydrostatic pressure available to invention to be utilized by rotor  32 , by increasing the pressure disparity upstream to the invention versus the lower pressure found on the downstream. 
     In  FIG. 19 ,  20  this embodiment of the device, the rotor  32  blades  61   c , are radially twisting on the rotor  32  hub  64 . The radial twisting or angling of said Blades  61   c  decreases the chance of entanglement at points where the rotatable portions of the device  31  come close to non-rotatable portions of device  31 , including but not limited to tether  21 . Operationally the radial twisting of blades  61   c  about hub  64  increases the hydrostatic pressure available to rotor  32  by directing a portion of current  71  towards the outside ends of hub  63 . This increases the relative water level on the upstream side of the rotor  32 , while decreasing relative water level on the downstream side. In addition this configuration increase the water power&#39;s stability and ability to remain optimally positioned relative to the current by increasing the currents force on the upstream side of the turbine and decreasing the force on the down stream side, having the effect of forcing the turbines into they preferred perpendicular position. 
     In  FIG. 21 ,  22  this embodiment of the device, the rotor  32  blades  61   d  combine a concave face on the side facing current  71  and are radially twisting about hub  63 . This combination of the prior embodiments further increases the efficiency in utilizing hydrostatic and hydro pressure to create usable energy. 
     In  FIG. 23 ,  24  this embodiment of the device, the rotor  32  blades  61   e  have a rounded corner on that potion located furthest away from the driven component  33 . This reduces risk to the invention and specifically the blade  61   e  from debris. It also reduces the damage that might occur to another object such as marine life if the blade  61   e  corner would come in contact it. 
     In  FIG. 25 ,  26  is an additional embodiment of this invention, the rotor  32  may be modified to reflect the environmental conditions of the current that it is positioned, and the requirements of the driven component. In one embodiment of the driven component  33 , the rotor  32  may incorporate a hub  64  that is smaller in diameter to increase the rotational speed of the hub  64 . The rotor  32  may be replaced with one with a larger diameter of hub  64  to reduce rotational speed in the same current. The rotor  32  hub  64  may be lengthened to provide additional buoyancy or shortened to reduce the buoyancy. The blades  61  may be lengthened or shortened to increase or decrease the desired surface area to come in contact with current  71 . 
     CONCLUSIONS, RAMIFICATIONS, AND SCOPE 
     Accordingly, the reader will see that the various embodiments of the buoyant in-stream hydro turbine offers greater efficiency in capturing energy from a current will reducing environmental and operational costs, such as additional support structures or other infrastructure. Furthermore, the buoyant in-stream hydro turbine has additional advantages in that:
         risk to the invention or marine life or object is reduced through embodiments including a single unified tether and rounded blade ends;   increased efficiency by reducing or eliminating drag on non rotatable parts;   increased utilization of the current&#39;s energy by restricting buoyancy to the rotor and increasing rotatable energy;   to maximizes the efficiency of a given driven component by allowing flexibility in rotor permutations to reflect the environmental conditions in which the turbine is to be placed.