Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/712,263 entitled TRILLIUM WIND TURBINE and filed on Oct. 11, 2012, which is specifically incorporated by reference herein for all that it discloses and teaches. 
    
    
     TECHNICAL FIELD 
     The invention relates generally to the field of wind turbines and wind power generation, and more particularly to a Trillium Wind Turbine apparatus. 
     BACKGROUND 
     Conversion of wind energy into a useful form of power has a long and storied history. For example, windmills were known and used by the Greeks at least by the first century AD; and windpumps or other wind-powered irrigation technologies were known hundreds of years earlier. Although still in use today to some degree, windmills, windpumps, and other wind-powered machinery have dramatically decreased in importance since the rise of fossil fuels. However, with increasing pollution, potential climate-change, and growing scarcity of these fuels, there has been a surge of interest in generating clean, renewable power from the wind. 
     Conventional wind turbines have been used to make electricity for more than a century. At the turn of the twentieth century, wind turbines were growing in popularity and their usefulness was recognized across the world. Today, commercial wind turbines can be found nearly anywhere the wind blows, from farms, to ranches, deserts and even open ocean. 
     However, conventional wind turbines have a number of problems and limitations. One of the most significant issues is that the wind often does not blow strongly enough throughout the day, nor can it be relied upon to blow adequately in a given location over a longer time span. Some locales have long histories of higher-than-average winds and, as such, are often targeted as potential sites for wind turbines. Nevertheless, even such high-grade wind sites have periods (sometimes days at a stretch) when the winds are light. Conventional turbines often require wind speeds of five, eight, or even ten miles-per-hour or higher before they start generating significant amounts of electricity. Furthermore, when the wind speed is too high, conventional wind turbines have to be adjusted so that the wind&#39;s effect on the blades is lessened or the blades may be deflected back into the support tower or otherwise become damaged. An additional problem with convention wind turbine systems is that they must employ an additional efficiency robbing system that senses wind direction and then actuates a servo motor to turn the turbine into the wind. When the winds constantly change direction, such systems do not respond quickly enough and lose efficiency. 
     What is needed is an advanced wind turbine apparatus that activates at lower-speed winds and can produce significant amounts of electricity at wind speeds below those required for conventional wind turbines. Furthermore, an advanced wind turbine apparatus should also weather high-speed wind situations without damaging its support tower or blades and should automatically align itself in the direction from which the wind is blowing without utilizing inefficient sensors and servo motors. 
     SUMMARY 
     One embodiment of the present invention comprises an apparatus having an electricity-generating, aerodynamic nacelle and a plurality of swept-back, complexly-curved blades. The blades can be made from any material that is lightweight and strong. Each blade has three primary subcomponents: a main blade, a trailing edge blade, and a diversion blade. The blades are pitched back with the face of the blade adjacent to the nacelle at roughly ninety degrees relative to the direction of the wind. This pushes the wind down the entire length of the blade before exiting at the tip. The main blade resembles a half-tube or portion of a cylinder in form, the tube being twisted approximately ninety degrees from the nacelle to the tip. This twist effectively and continuously changes the angle of attack, thereby adding more lift (without stall) throughout the length of the blade. The trailing edge blade is pitched relative to the direction of the wind, thus producing more lift. The diversion blade is also at a pitch relative to the direction of the wind. Thus, when wind hits the diversion blade it produces additional lift. Additionally, because of the shape and placement of the diversion blade, the wind hitting the diversion blade is diverted behind the blade so as to not interfere with the wind traveling along the length of the main blade from the nacelle to the tip. And because the surface area/volume is much bigger near the nacelle and smaller at the tip, the air that travels along the main blade increases in velocity as it travels down the blade producing more thrust/lift. All of these features cause the advanced trillium wind turbine apparatus to be much more efficient than conventional wind turbines and thus allows the trillium to produce electricity in winds so light that other wind turbines stall out and cease to function. Furthermore, in more moderate winds, the trillium wind turbine extracts more usable energy from the wind, effectively allowing it to spin a larger generator than a conventional turbine (or spin the same size generator at a greater speed). In either case, the trillium wind turbine apparatus can produce more electricity versus a conventional wind turbine system. Additionally, because the tower/support structure that holds the blades and nacelle up in the air is attached to the nacelle and the blades are swept back behind the nacelle, the trillium wind turbine automatically faces into the wind without the need for inefficient sensor(s) and additional positioning motor(s). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following descriptions of a preferred embodiment and other embodiments taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  shows a front elevation view of an exemplary embodiment of a trillium wind turbine; 
         FIG. 2  illustrates a left elevation view of an exemplary embodiment of a trillium wind turbine; 
         FIG. 3  illustrates a back elevation view of an exemplary embodiment of a trillium wind turbine; 
         FIG. 4  illustrates a top plan view of an exemplary embodiment of a trillium wind turbine; 
         FIG. 5  illustrates a bottom plan view of an exemplary embodiment of a trillium wind turbine; 
         FIG. 6  illustrates a front elevation view of an exemplary blade of a trillium wind turbine showing a number of cross-section lines; 
         FIGS. 7A-7F  illustrate cross-sectional views of an exemplary blade of a trillium wind turbine; 
         FIG. 8  shows a front elevation view of an exemplary embodiment of a trillium wind turbine having only two blades. 
     
    
    
     DETAILED DESCRIPTION 
     In the following discussion, numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, those skilled in the art will appreciate that embodiments may be practiced without such specific details. Furthermore, lists and/or examples are often provided and should be interpreted as exemplary only and in no way limiting embodiments to only those examples. 
     Exemplary embodiments are described below in the accompanying Figures. The following detailed description provides a comprehensive review of the drawing Figures in order to provide a thorough understanding of, and an enabling description for, these embodiments. One having ordinary skill in the art will understand that in some cases well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments. 
     Referring now to the drawings,  FIG. 1  shows a front elevation view of an exemplary embodiment of a trillium wind turbine  100 . In the embodiment shown in  FIG. 1 , the wind turbine apparatus  100  employs three blades  101 ,  102 , and  103 . In other embodiments, the number of blades  101 ,  102 , and  103  can be one, two, three, four, or more. The individual components that make up each of the blades are not highlighted in  FIG. 1 , see  FIG. 6 . 
     The aerodynamically-shaped, electricity generating nacelle  700  is shown in  FIG. 1  as being located in front of the plurality of blades  101 ,  201 , and  301  with the tower/support structure  800  mounted to the nacelle  700 . This location has a number of benefits. First, because the mounting tower/support structure  800  attaches to the nacelle  700 , and the blades  101 ,  201 , and  301  are swept-back from the nacelle  700  (and attached to the rotor shaft, not shown in  FIG. 1 , see rotor shaft  750  in  FIG. 2 ), the blades can not be forced by high winds into impacting with the tower  800  (as could happen in conventional wind turbine systems where the blades are in front of the tower and can be distorted or bent backwards in very high-wind situations). Additionally, because the blades  101 ,  201 , and  301  are attached to the rotor shaft behind the nacelle  700  and the tower  800  and are swept backwards, the apparatus automatically turns to face into the wind. This is accomplished by a turntable device (or any similarly functioning device) between the tower  800  and the nacelle  700  which allows the nacelle and blades to turn to face any direction. And, as the wind blows against the turbine, the turbine provides the least resistance to the wind when it is directly facing into it, thus, the wind automatically turns the turbine into the wind. This provides a significant advantage over other systems which require the use of a sensor and an actuator motor to ensure that the wind turbine is always facing directly into the wind. 
     It is preferred that the tower/support-structure  800  be attached to the nacelle  700  and in front of the plurality of blades  101 ,  201 , and  301  with the nacelle  700  extending forward of the blades, and the blades sweeping back therefrom. As illustrated in  FIG. 1 , with the blades  101 ,  201 , and  301  being positioned behind the nacelle  700  and tower  800 , the blades act as a vane and help to keep the entire trillium wind turbine  100  oriented into the wind. 
       FIG. 2  illustrates a left elevation view of an exemplary embodiment of a trillium wind turbine  100 . The turbine  100  is illustrated from the side so that the swept-back nature of the blades  101 ,  201 , and  301  is apparent (note attachment of the blades behind the nacelle  700  and the location of the blade tips  190 ,  290 , and  390  well back from the nacelle  700 ). 
     The blades  101 ,  201  and  301  are and cupped inwards to catch and direct the incoming wind  144  down the length of the blade. Using what is the middle blade  101  in this view as an example, each blade has an edge extension  110  and a trailing edge blade  130  that, together with the main blade  150  between them, form a trough or partial tube/cylinder extending from the nacelle  700  outwards and back to the tip of the blade  190 . The edge extension  110  extends from the nacelle  700  down towards the tip of the blade  190 , first rapidly increasing in height from the main blade  150  and then gradually decreasing before disappearing completely before reaching the blade tip  190 . The trailing edge blade  130  also first increases and then decreases in height relative to the main blade  150 , and eventually disappears completely as well before reaching the tip  190 . The main blade  150  funnels the incoming wind down the blade  101  and extends through to the tip of the blade  190 . See  FIGS. 7A-7F  for more detail of the blade shape. 
     The twist of the blades  101 ,  201 , and  301  also helps direct the incoming wind  144  so that it acts on the edge extension  110 , trailing edge blade  130  and main blade  150  to spin the blade  101  on the rotor  750 . The front surface of the main blade  150  faces approximately forwards into the incoming wind  144  near the nacelle; and, at the blade tip  190 , it eventually twists nearly ninety degrees to face approximately downwards. 
     In the embodiment shown in  FIG. 2 , the rotor shaft  750  is clearly visible. It extends into the nacelle  700  and serves to transfer the rotary motion of the blades  101 ,  201 , and  301  into rotational energy which the nacelle  700  converts into electricity. The rotor shaft  750  is connected to each blade by an attachment block (see items  760 ,  770 , and  780  in  FIG. 3 ). 
       FIG. 2  also clearly illustrates the relative position of the nacelle  700 , the swept-back blades  101 ,  201  and  301 , and the support structure/tower  800 . As can be seen by the Wind Direction arrow  144 , the wind is blowing from the right and contacts first the nacelle  700 , then the tower  800 , and finally the blades  101 ,  201  and  301 . This configuration allows the trillium wind turbine  100  to automatically face into the wind as wind pressure against the blades causes them to act like vanes, forcing the nacelle  700  to spin on its mounting atop the tower  800  to point directly into the wind. 
       FIG. 3  illustrates a back elevation view of an exemplary embodiment of a trillium wind turbine  100 . The turbine  100  is illustrated in the three-blade  101 ,  201 , and  301  configuration of  FIGS. 1-2 . The back view shown in  FIG. 3  provides a view of the three blade attachment blocks  760 ,  770  and  780 . The attachment blocks are an exemplary means for securing the blades  101 ,  201 , and  301  to the rotor shaft and the nacelle  700 . 
       FIG. 4  illustrates a top plan view of an exemplary embodiment of a trillium wind turbine  100 . A single blade attachment block  760  is visible in this view and it should be apparent to one skilled in the art that other types of attachment mechanisms can be used to secure a blade to the rotor shaft  750  and/or nacelle  700 . In this view, the sides of the blades are shown to more clearly illustrate the shape of the main blade  150  and the location and shape of the diversion blade  117  relative to the edge extension  110  and the tip  190 . The general size and shape of the blade  150  is illustrated: the area and volume of the blade adjacent to the nacelle is the greatest and then reduces along the length of the blade until the area and volume of the blade is very small at the tip. 
       FIG. 5  illustrates a bottom plan view of an exemplary embodiment of a trillium wind turbine  100 . The tower  800  and nacelle  700  are visible in this view as is a single attachment block  760 . Because of the position of the blades  101 ,  201 , and  301 , all three can be seen.  FIG. 5  illustrates the backwards pitch of the blades relative to the nacelle  700 . The backward pitch reduces the amount of shear stress on the tower and/or support structure (similar to the reduced shear resistance of a swept back or delta wing of a jet fighter), and the horizontal dynamic load that needs to be appropriately restrained by the foundation of the trillium wind turbine apparatus. 
       FIG. 6  illustrates a front elevation view of an exemplary blade  101  of a trillium wind turbine showing a number of cross-section lines A, B, C, D, E, and F. The nacelle  700  displays an “X” axis and a “Y” axis; the “Z” axis is positioned at the origin of the “Y” and “X” axes and extends outwards from the Figure so is it not visible in  FIG. 6 , see  FIGS. 7A-7F . The “X” axis helps to show the overall curvature and twist of the exemplary embodiment of the blade  101  shown in  FIG. 6 . 
     Extending back from the nacelle  700  is the main blade  150  which makes up a large portion of the blade  101  itself. Nearest the nacelle  700 , the blade  101  has an edge extension  110  that extends from the main blade  150  and helps to catch and direct more wind onto/into the blade  101 . The first cross-section, labeled A, is taken through the edge extension  110  and the beginning curve of the main blade  150  (see  FIG. 7A , cross-section). 
     Running along the outer leading edge  115  of the edge extension  110  is the diversion blade  117 . The diversion blade  117  is attached to the outer surface of the edge extension  110  and extends outwards to attach to the back surface of the main blade  150  near the tip  190 . As can be seen in the cross-section of  FIGS. 7A-F , the diversion blade  117  is at a pitch relative to the direction of the wind. Between the two attachment points, the diversion blade  117  bows outwards from the leading edge  115  and creates a gap between itself and the main blade  150 . This gap allows the diversion blade  117  to divert some of the wind behind the blade  101  so as to not interfere with the wind traveling along the length of the main blade  150  from the nacelle  700  to the tip  190 . It is important to note that a secondary purpose of the diversion blade  117  is that when wind hits the diversion blade  117 , it produces additional lift. The second cross-section, labeled B, is taken just before the diversion blade  117 , and includes the edge extension  110 , the curve of the main blade  150 , and the trailing edge blade  130  (see  FIG. 7B , cross-section). 
     The trailing edge blade  130  extends outwards from the main blade  150  generally in parallel to the direction of the wind so that the wind is blowing across it. The trailing edge blade  130  functions in part to keep the wind “in” and acting upon the main blade  150  as it travels down the blade. Furthermore, the underside of the trailing edge blade  150  is at a pitch relative to the wind direction, thus producing additional lift. The third and fourth cross-sections, labeled C and D, respectively, include the diversion blade  117 , the outer leading edge  115  of the edge extension  110  and the edge extension  110  itself, the curve of the main blade  150 , and the trailing edge blade  130 . 
     The fifth cross-section, labeled E, includes the diversion blade  117  but not edge extension  110  since it ended between D and E. Cross-section E also includes the main blade  150  and the trailing edge blade  130 . The final cross-section is labeled F and is taken near the tip  190  of the main blade  150 . The progression across the cross-sections helps to understand the changing nature of the underlying complex curves (see  FIGS. 7A-7F ). 
     The outer leading edge  115  changes orientation relative to the main blade  150  as you move from the nacelle  700  to the tip  190 . This occurs because of the roughly ninety-degree twist in the main blade  150  as you move from the nacelle  700  to the tip  190 . 
     The diversion blade  117  is at an angle of attack to the relevant wind, thereby adding additional lift to the turbine. The wind deflected by the diversion blade  117  is directed behind the main blade, and there imparts a positive aerodynamic influence by reducing the pressure behind the main blade. Additionally, the aerodynamic design of the nose-cone-shaped nacelle  700  diverts air to the blades. 
       FIGS. 7A-7F  illustrate cross-sectional views of an exemplary blade  101  of a trillium wind turbine  100 . Note the axes shown in FIGS.  6  and  7 A- 7 F for reference in order to help orient the viewer to the locations of the cross-sectioned components. The viewer should understand that because the blade  101  is swept back and does not extend parallel to the “X” axis in  FIG. 6 , the cross-sections appear somewhat elongated. The “X” axis in  FIGS. 7A-7F  is located at the origin of the “Y” and “Z” axes, but extends “outwards” from the Figure towards the viewer so is not visible. 
       FIG. 7A  illustrates a side elevation view of the “A” cross-section noted in  FIG. 6 . The front surface of the main blade  150  is illustrated in  FIG. 7A . Given that the “X” axis extends outwards from the Figure towards the viewer, the swept-back nature of the main blade  150  should be apparent. The cupped nature of the main blade  150  is apparent form the cross-section, as is the relatively straight nature of the edge extension  110  that extends from the main blade  150 . 
       FIG. 7B  illustrates a side elevation view of the “B” cross-section noted in  FIG. 6 . This cross-section view includes the features shown in  FIG. 7A , while introducing the trailing edge blade  130 . 
     Cross-section “C” is illustrated in  FIG. 7C  and includes the same components as B, but is taken further down the main blade  150  so it introduces the diversion blade  117 . 
       FIG. 7D  illustrates cross-section “D” which highlights the fact that the gap between the diversion blade  117  and the main blade  150  first grows and then continues to narrow as you approach the blade tip. Further, the cup-like shape of the blade is very apparent in  FIG. 7D . 
     In cross-section E, shown in  FIG. 7E , the twist of the main blade  150  is almost complete as the diversion blade  117  comes to an end. What little of the main blade  150  that remains near the blade tip is nearly parallel with the wind direction and the “X”-“Z” plane (formed by the “X” axis and the “Z” axis). In some embodiments, the cross-sections B to E will have a trailing edge blade at an angle of attack to the relevant wind thereby providing additional lift. In yet other embodiments, the components described above will have varying angles as the rate of twist and/or overall twist can be greater than or less than that described above. 
       FIG. 7F  illustrates cross-section “F” which highlights the fact that the diversion blade  117  and the trailing edge blade  130  both come to an end before the tip of the blade is reached. In  FIG. 7F , only the main blade  150  remains to extend through the tip of the blade. 
       FIG. 8  shows a front elevation view of an exemplary embodiment of a trillium wind turbine having only two blades  101  and  201 . As discussed above, a trillium wind turbine can have any number of blades. Here, a two-blade wind turbine  100  is illustrated. Note that the nacelle  700  is also shown. Although not explicitly shown, the connection components (the attachment blocks) that connect the blades  101  and  201  to the rotor shaft can include a mechanism to automatically furl the blades in high-wind situations. In order to see more detail of the blades, the tower is not shown in  FIG. 8 . 
     While particular embodiments have been described and disclosed in the present application, it is clear that any number of permutations, modifications, or embodiments may be made without departing from the spirit and the scope of this disclosure. 
     Particular terminology used when describing certain features or aspects of the embodiments should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects with which that terminology is associated. In general, the terms used in the following claims should not be construed to be limited to the specific embodiments disclosed in the specification, unless the above Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the claims encompasses not only the disclosed embodiments, but also all equivalent ways of practicing or implementing the claimed subject matter. 
     The above detailed description of the embodiments is not intended to be exhaustive or to limit the invention to the precise embodiment or form disclosed herein or to the particular field of usage mentioned in this disclosure. While specific embodiments of, and examples for, the invention are described above for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize. Also, the teachings of the invention provided herein can be applied to other systems, not necessarily the system described above. The elements and acts of the various embodiments described above can be combined to provide further embodiments. 
     Any patents, applications and other references that may be listed in accompanying or subsequent filing papers, are incorporated herein by reference. Aspects of the invention can be modified, if necessary, to employ the systems, functions, and concepts of the various references to provide yet further embodiments of the invention. 
     In light of the above “Detailed Description,” the Inventor may make changes to the invention. While the detailed description outlines possible embodiments of the invention and discloses the best mode contemplated, no matter how detailed the above appears in text, the invention may be practiced in a myriad of ways. Thus, implementation details may vary considerably while still being encompassed by the spirit of the invention as disclosed by the inventor. As discussed herein, specific terminology used when describing certain features or aspects of the invention should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the invention with which that terminology is associated. 
     While certain aspects of the invention are presented below in certain claim forms, the inventor contemplates the various aspects of the invention in any number of claim forms. Accordingly, the inventor reserves the right to add additional claims after filing the application to pursue such additional claim forms for other aspects of the invention. 
     The above specification, examples and data provide a description of the structure and use of exemplary implementations of the described articles of manufacture and methods. It is important to note that many implementations can be made without departing from the spirit and scope of the invention.

Technology Category: 2