Patent Publication Number: US-2010129219-A1

Title: Systems and Methods for Generating Energy Using Wind Power

Description:
FIELD 
     This application relates generally to systems and methods for generating energy, such as electrical energy, using wind power. 
     BACKGROUND 
     Wind turbines have been used to generate electrical energy from wind power. While existing wind turbines may provide some energy, they are not very efficient. This is because existing wind turbines can make use of only some of the wind power received directly by rotors of the wind turbines for conversion to electrical energy. Wind reflected from such rotors is not reused. 
     SUMMARY 
     In accordance with some embodiments, a wind turbine for generating energy includes a first rotor having a first set of blades and a first shaft, and a second rotor having a second set of blades and a second shaft, wherein the first rotor is configured to rotate in a first direction, and the second rotor is configured to rotate in a second direction that is opposite to the first direction. 
     In accordance with other embodiments, a wind turbine for generating energy includes a first rotor having a first set of blades and a first shaft, and a second rotor having a second set of blades and a second shaft, wherein one of the first set of blades is oriented to receive wind for turning the first rotor, and wherein one of the second set of blades is oriented an at angle to receive wind that is deflected from one of the first set of blades for turning the second rotor. 
     Other and further aspects and features will be evident from reading the following detailed description of the embodiments, which are intended to illustrate, not limit, the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the design and utility of embodiments, in which similar elements are referred to by common reference numerals. These drawings are not necessarily drawn to scale. In order to better appreciate how the above-recited and other advantages and objects are obtained, a more particular description of the embodiments will be rendered, which are illustrated in the accompanying drawings. These drawings depict only typical embodiments and are not therefore to be considered limiting of its scope. 
         FIG. 1  illustrates a wind turbine in accordance with some embodiments; 
         FIGS. 2A and 2B  illustrate a first rotor for the wind turbine of  FIG. 1  in accordance with some embodiments; 
         FIG. 2C  illustrates a second rotor for the wind turbine of  FIG. 1  in accordance with some embodiments; 
         FIG. 2D  is an elevation view of the first and second rotors of  FIGS. 2A and 2B , showing deflected wind; 
         FIGS. 3A and 3B  illustrate a first rotor for the wind turbine of  FIG. 1  in accordance with some embodiments; 
         FIG. 3C  illustrates a second rotor for the wind turbine of  FIG. 1  in accordance with some embodiments; 
         FIGS. 4A and 4B  illustrate another rotor in accordance with other embodiments; 
         FIG. 5A  illustrate a rotor in accordance with some embodiments, showing a blade&#39;s axis aligned with a radial axis of the rotor; 
         FIG. 5B  illustrate a rotor in accordance with other embodiments, showing a blade&#39;s axis forming an angle with a radial axis of the rotor; 
         FIG. 6A  illustrates components within a wind turbine in accordance with some embodiments; 
         FIG. 6B  illustrates components within a wind turbine in accordance with other embodiments; 
         FIG. 7  illustrates a wind turbine in accordance with other embodiments; 
         FIG. 8  illustrates a wind turbine that has four rotors in accordance with some embodiments; 
         FIG. 9A  illustrates a wind turbine that has three rotors in accordance with other embodiments; 
         FIG. 9B  illustrates a wind turbine that has four rotors in accordance with some embodiments; 
         FIG. 10  illustrates a rotor in accordance with other embodiments; 
         FIG. 11  illustrates a rotor in accordance with other embodiments; 
         FIG. 12  illustrates; and 
         FIG. 13  illustrates a wind turbine in accordance with other embodiments. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Various embodiments are described hereinafter with reference to the figures. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention. In addition, an illustrated embodiment needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated. 
       FIG. 1  illustrates a wind turbine  100  in accordance with some embodiments. The wind turbine  100  includes a base  102 , a support structure  104 , a first rotor  106 , and a second rotor  108 . The first and second rotors  106 ,  108  are coupled to the support structure, which supports the rotors  106 ,  108 . The first and second rotors  106 ,  108  are configured to receive wind power, and rotate relative to the support structure  104  in response to the wind power. The wind turbine  100  also includes a generator (not shown), which is configured to convert rotational energy provided by the rotating rotors  106 ,  108  to electrical energy. 
     The first rotor  106  has a first set of blades  110  and a first shaft  112 , and the second rotor  108  has a second set of blades  120  and a second shaft  122 . The first set of blades  110  are supported on a plate  113  and are connected to a hub  115 . The second set of blades  120  are supported on a plate  123  and are connected to a hub  125 . As used in this specification, the term “blade” refers to any structure having a surface for allowing wind to push thereagainst, and is not limited to structure having a particular geometry. For example, in the illustrated embodiments, the blades  110 ,  120  each has a plate configuration. However, in other embodiments, each of the blades  110 ,  120  can have other configurations, such as a block-like configuration. Also, in other embodiments, the plates  113 ,  123  are not required, and the wind turbine  100  does not include the plates  113 ,  123 . In such cases, each blade  110 / 120  will have an angle configuration that allows wind from one direction to be captured at the space between the legs of the angle. In other embodiments, the blade  110 / 120  can have other configurations as long as it can capture wind and utilize the wind power to turn the rotor. 
     The rotors  106 ,  108  can have different sizes in different embodiments. In some embodiments, each of the rotors  106 ,  108  may have a width that is between 2 inches and 1000 feet. For example, in some embodiments, each of the rotors  106 ,  108  has a width  150  that is between 5 feet and 500 feet, or more. In such cases, the support structure may be in the form of a tower. In other embodiments, each of the rotors  106 ,  108  has a width that is between 6 inches and 24 inches. In such cases, the support structure may be in the form of a hand-held device. The rotors  106 ,  108  can have other dimensions in other embodiments. 
     Also, each rotor  106 / 108  can have number of blades that are different from that shown. For example, each rotor  106 / 108  may have less than 6 blades or more than 6 blades. Also, in other embodiments, the number of blades for the first rotor  106  may be different from the number of blades for the second rotor  108 . 
     In the illustrated embodiments, each of the hubs  115 ,  125  has a central opening. The second shaft  122  may be secured to the second rotor  108  by inserting part of the second shaft  122  into the hub&#39;s  125  opening, which provides a frictional fit to the second shaft  122 . Alternatively, the second shaft  122  may be secured to the second rotor  108  using other mechanical devices, such as a connector, which may include one or more screws, etc. The first shaft  112  may be secured to the first rotor  106  using similar techniques. In some embodiments, the opening at the hub  125  is larger than the opening at the hub  115 , so that the opening at the hub  125  can accommodate both the first shaft  112  and the second shaft  122 . In other embodiments, the hub  125  does not include the opening, in which case, the shaft  122  may be secured to the bottom surface of the hub  125 . As shown in the figure, the first shaft  112  of the first rotor  106  has an opening  130 , and the second shaft  122  of the second rotor  108  is located within the opening  130  such that the second shaft  122  is located coaxially relative to the first shaft  112 . 
     In the illustrated embodiments, the first rotor  106  is configured to rotate in a first direction  140 , and the second rotor  108  is configured to rotate in a second direction  142  that is opposite to the first direction  140 . Such is accomplished by orienting the first set of blades  110  relative to the second set of blades  120  such that wind deflected from a blade  110  in the first set is received by a blade  120  in the second set. During use, wind deflected from the first set of blades  110  is received by the second set of blades  120 , which use the deflected wind from the first set of blades  110  to turn the second rotor  108 . In some cases, the opposite may also happen—i.e., wind deflected from the second set of blades  120  is received by the first set of blades  110 , which use the deflected wind from the second set of blades  120  to turn the first rotor  106 . For example, as shown in  FIG. 2A , wind W 1 , W 2  may impinge upon two blades  110  of the first rotor  106 , which capture the wind W 1 , W 2  at the space that are formed between the blades  110  and the disk  113 , thereby causing the rotor  106  to turn in the direction  140  shown. This is because the angle formed by the blade  110  and the disk  113  that is facing towards the on-coming wind (e.g., wind W 1 , W 2 ) creates a significant drag to the wind, thereby allowing the blade  110  to utilize the wind power to turn the rotor  106 . On the other hand, wind W 3 , W 4  may impinge upon another two blades  110  of the first rotor  106 , which deflect the wind upward as shown in the figure. The deflected wind W 3 , W 4  are captured by the blades  120  of the second rotor  108  at the space that are formed between the blades  120  and the disk  123 , thereby causing the second rotor  108  to turn in the direction  142  shown ( FIG. 2C ). Similarly, wind W 5  that impinges upon another blade  120  fo the second rotor  108  may be deflected downward, which in turn, is captured by the blade  110  of the first rotor  106  at the space that is formed between the blade  110  and the disk  113 , thereby causing the first rotor  106  to turn in the direction  140  shown ( FIG. 2B ).  FIG. 2D  illustrates an elevation view of the first and second rotors  106 ,  108 , showing wind W 3  being deflected from blade  110  of the first rotor  106  to blade  120  of the second rotor  108 , and wind W 5  being deflected from blade  120  of the second rotor  108  to blade  110  of the first rotor  106 . 
     It should be noted that wind coming from the opposite direction as that shown in the figure would cause the rotors  106 ,  108  to operate in a similar manner. For example, as shown in  FIG. 3A , wind W 6  may impinge upon a blade  110  of the first rotor  106 , which capture the wind W 6  at the space that is formed between the blade  110  and the disk  113 , thereby causing the rotor  106  to turn in the direction  140  shown. On the other hand, wind W 7  may impinge upon another blade  110  of the first rotor  106 , which deflect the wind upward as shown in the figures ( FIGS. 3A ,  3 B). The deflected wind W 7  is captured by the blade  120  of the second rotor  108  at the space that are formed between the blades  120  and the disk  123 , thereby causing the second rotor  108  to turn in the direction  142  shown ( FIG. 3C ). Similarly, wind W 8  that impinges upon another blade  120  of the second rotor  108  may be deflected downward, which in turn, is captured by the blade  110  of the first rotor  106  at the space that is formed between the blade  110  and the disk  113 , thereby causing the first rotor  106  to turn in the direction  140  shown ( FIG. 3B ). 
     The above described feature is advantageous in that it allows deflected wind from the first rotor  106 , which is otherwise lost or not utilized by the first rotor to generate energy, to be utilized by the second rotor  108 , and vice versa. As illustrated in the embodiments, the amount of energy generated by oncoming wind is greatly increased by deflecting the wind in a bi-directional manner across the two sets of blades. In some embodiments, such feature provides at least a 50% energy efficiency, and in some cases, a 80% energy efficiency or more. 
     In the illustrated embodiments, each of the rotors  106 ,  108  has a circular disk configuration ( FIG. 2A ) in which the width  150  of the rotor is longer than the thickness  152 . However, in other embodiments, the rotors  106 ,  108  may have a configuration that is different from that illustrated. For example, in other embodiments, each rotor may have a non-circular configuration, such as an elliptical configuration, a square configuration, a triangular configuration, a pentagonal configuration, a hexagonal configuration, etc. Also, in other embodiments, the thickness of the rotor may be the same or longer than the width of the rotor. 
     Also, in other embodiments, the rotors  106 ,  108  may be configured to rotate in respective directions that are opposite to those (directions  140 ,  142 ) illustrated in  FIG. 1 .  FIGS. 4A and 4B  illustrate a rotor  106  that is the same as that illustrated in  FIG. 2 , except that the blades  110  are oriented in different angles. Such configuration allows the rotor  106  to be rotated in the direction  160  shown. Similar is true with respect to the second rotor  108 . 
     In any of the embodiments described herein, the blades  110 / 120  (e.g., edges of the blades) of the rotors  106 / 108  may align with respective radial axes  180  of the rotors  106 / 108  ( FIG. 5A ). In other embodiments, the blades  110 / 120  of the rotors  106 / 108  may form angles  182  with respective radial axes  180  of the rotors  106 / 108  ( FIG. 5B ). In some cases, such configuration may allow wind to be captured more efficiently. 
     In any of the embodiments described herein, the wind turbine  100  may include one or more gearbox(es) for converting slowly rotating, high torque powers from the respective rotors to high speed, low torque power. For example, in some embodiments, the first shaft  112  is coupled to a first gearbox  502 , and the second shaft  122  is coupled to a second gearbox  504  ( FIG. 6A ). The gearboxes  502 ,  504 , are in turn, coupled to respective power generators  512 ,  514 . The power generators  512 ,  514  are configured to convert rotational energy into electrical energy. Each of the power generators  512 ,  514  may be an induction generator, or other types of generator. In other embodiments, instead of having different gearboxes for the respective rotors, two (or more—if more than two rotors are provided) of the rotors of the wind turbine  100  can share the same gearbox. Also, in further embodiments, instead of having power generators  512 ,  514  for the respective rotors, the wind turbine  100  can have a single generator  520  for converting rotational energy from the rotors to electrical energy ( FIG. 6B ). 
     In other embodiments, the wind turbine  100  does not include any gearbox, and instead, relies on a direct drive. In such cases, the generator  13  may be a permanent magnet synchronous generator (PMSG) capable of generating power at a low rotational speed. 
     In the above embodiments, the wind turbine  100  has been described as having two shafts  112 ,  122  that are located co-axially relative to each other. In other embodiments, the wind turbine  100  needs not have such configuration. For example, in other embodiments, the first rotor  106  may be fixedly secured to the shaft  112 , which extends through an opening  700  in the second rotor  108  ( FIG. 7 ). In the figure, the blades are not shown for clarity. The shaft  112  is coupled to a first gearbox  502 , and the second rotor  108  is coupled to a second gearbox  504 . In some embodiments, the periphery of the second rotor  108  may include a saw-tooth structure that provide a gear function for the second rotor  108 . The saw-tooth structure engages with a gear in the gearbox  504 , and turns the gear at the gearbox  504  when the second rotor  108  rotates. 
     In any of the embodiments described herein, the wind turbine  100  may include additional rotors. For example, in other embodiments, the wind turbine  100  may include an additional pair of rotors, i.e., a third rotor  300  and a fourth rotor  400  ( FIG. 8 ). In such cases, the third rotor  300  has a third set of blades  310  and a third shaft  312 , and the fourth rotor  400  has a fourth set of blades  410  and a fourth shaft  412 . In the illustrated embodiments, the second shaft  122  has an opening  320 , and the third shaft  312  of the third rotor  300  is located within the opening  320  of the second shaft  122  such that the third shaft  312  is located coaxially relative to the second shaft  122 . Also, the third shaft  312  has an opening  330 , and the fourth shaft  412  of the fourth rotor  400  is located within the opening  330  of the third shaft  312  such that the fourth shaft  412  is located coaxially relative to the third shaft  312 . During use, wind deflected from the third set of blades  310  is received by the fourth set of blades  410 , which use the deflected wind from the third set of blades  310  to turn the fourth rotor  400 . In some cases, the opposite may also happen—i.e., wind deflected from the fourth set of blades  410  is received by the third set of blades  310 , which use the deflected wind from the fourth set of blades  410  to turn the third rotor  300 . 
     In further embodiments, the wind turbine  100  may include more than four rotors. For example, in other embodiments, the wind turbine  100  may include six or more rotors, such as 10 rotors. In some cases, the turbine may include any number of rotors, and may be multi-tiered to include many groups or sets (e.g., groups or sets of two) of blades. The rotors may be aligned relative to each other to form a series. The rotors may also be aligned in different configurations in different embodiments. 
     Similarly, for the embodiment of the wind turbine shown in  FIG. 7 , there can be more than two rotors  106 ,  108 .  FIG. 9A  illustrates a variation of the wind turbine  100  of  FIG. 7  in accordance with some embodiments. The wind turbine  100  includes three rotors  106   a ,  106   b ,  108 . In the figure, the blades are not shown for clarity. The rotors  106   a ,  106   b  are both fixedly secured to the shaft  112 . The shaft  112  extends through the opening  700  at the rotor  108 , which can rotate relative to the shaft  112 . The shaft  112  is coupled to a first gearbox  502 . Thus, the rotating of the rotors  106   a ,  106   b  will cause the gearbox  502  to be activated (e.g., will move a component in the gearbox  502 ). The rotor  108  is coupled to a second gearbox  504  at its periphery (e.g., via saw-tooth structure, not shown), and rotation of the rotor  108  will cause the second gearbox  504  to be activated. 
     In other embodiments, the wind turbine of  FIG. 9A  can have one or more additional rotors.  FIG. 9B  illustrates a wind turbine  100  that has four rotors  106   a ,  106   b ,  108   a ,  108   b . In the figure, the blades are not shown for clarity. The rotors  106   a ,  106   b  are fixedly secured to the shaft  112 . The shaft  112  extends through the opening  700   a  at the rotor  108   a , and the opening  700   b  at the rotor  108   b . The rotors  108   a ,  108   b  can rotate relative to the shaft  112 . In the illustrated embodiments, the rotating of the rotors  106   a ,  106   b  will activate the gearbox  502 . The rotating of the rotors  108   a ,  108   b  will activate gearboxes  504   a ,  504   b , respectively. 
     In other embodiments, the wind turbine  100  may include a first set of two or more rotors  106 , and a second set of two or more rotors  108  that are staggered (e.g., in an alternating pattern) with the first set. In such cases, the rotors  106  may be all fixedly secured to the shaft  112 . The rotors  108  are located between the rotors  106 , and each rotor  108  includes an opening for allowing the shaft  112  to extend therethrough, thereby allowing each rotor  108  to rotate relative to the shaft  112 . During use, the rotors  106  will all rotate in a first direction, and the rotors  108  will rotate in a second direction that is different from the first direction. The shaft  112  for the first set of rotors  106  may be coupled to a first gearbox, while the rotors  108  from the second set may be coupled to respective gearboxes at the respective peripheries of the rotors  108 . 
     In any of the embodiments described herein, the rotor  106 / 108  may not include disk  113 / 123 . For example, in some embodiments, the blades  110  may be secured to the hub  115  without any support by a disk  113  ( FIG. 10 ). In such cases, each blade  110  may include a first portion  800  and a second portion  802 , which together form an angle. During use, wind W 1  coming from one direction is captured by the angle at the space  804  that is between the portions  800 ,  802 . The angle creates a significant drag for the wind W 1 , thereby using the wind energy to turn the rotor. On the other hand, wind W 2  coming from another direction is not captured by the angle, and is instead, deflected by the portion  800 . The deflected wind may be captured by an adjacent rotor, which uses the deflected wind to turn the adjacent rotor, as similarly discussed herein. 
       FIG. 11  illustrates another rotor, which may be used in any of the embodiments described herein. Unlike the rotor shown in  FIG. 10  in which the second portion  802  is oriented horizontally, the rotor in  FIG. 11  has second blade portions  802  that are not oriented horizontally. In some embodiments, such rotor may be used as the rotor  108  in the embodiment of  FIG. 9A . 
       FIG. 12  illustrates a wind turbine  100  in accordance with other embodiments. The wind turbine  100  has three rotors  106   a ,  106   b ,  108 . The rotor  108  has the configuration shown in  FIG. 11 , and the rotor  106   a  has the configuration shown in  FIG. 4B . During use, wind is deflected from blades  110   a ,  110   b  (e.g., above and below the rotor  108  on one side of the hub  115 ) towards a blade  120  of the rotor  108 . The deflected wind is received by the angle of the blade  120 , and pushes the blade  120  to thereby rotate the rotor  108  in the direction  850 . On the other side of the hub  115 , wind is deflected from the first portion  800  and the second portion  802  of the blade  120  towards the rotor&#39;s  106   b  blade  110   b , and the rotor&#39;s  106   a  blade  110   a , respectively. The deflected wind is received by the blade  110   a , and pushes the blade  110   a  to thereby rotate the rotor  106   a  in the direction  852 . Similarly, the deflected wind is reflected by the blade  110   b , and pushes the blade  110   b  to thereby rotate the rotor  106   b  in the direction  852 , which is the same direction as that for the rotor  106   a , but is in the opposite direction as that for the rotor  108 . In some embodiments, the rotor  108  may be coupled to a gear box (not shown) at its periphery, as similarly described herein. Also, in other embodiments, instead of the rotor  106   b , the wind turbine  100  may include another rotor having a configuration that is the same as the rotor  108 , except that the blades  120  are reversed. In further embodiments, the wind turbine  100  may include more than two rotors  108 , such as three rotors  108 , four rotors  108 , or more, that are stacked in an array. The rotors  108  may have respective blades  120  that alternate in orientation, such that every other rotors  108  in a first set would rotate in one direction, and the adjacent rotors in a second set would rotate in another direction. 
     In the above embodiments, each of the shafts  112 ,  122  extends in a vertical direction. In such cases, the wind turbine  100  may be called a vertical-axis wind turbine (VAWT). However, in other embodiments, the rotors  106 ,  108  can have different orientations, and the shafts  112 ,  122  may extend in different directions. For example, in other embodiments, each of the shafts  112 ,  122  may extend in a horizontal direction ( FIG. 13 ). In such cases, the wind turbine  100  may be called a horizontal-axis wind turbine (HAWT). Also, in other embodiments, instead of having two shafts  112 ,  122  that are positioned coaxially relatively to each other, the wind turbine  100  of  FIG. 12  may have a configuration that is similar to that shown in  FIG. 7 . In such cases, the shaft  112  is fixedly secured to one of the rotors, and extend through an opening at the other one of the rotors. The shaft  112  may be coupled to a first gearbox, and the other rotor may be coupled to a second gearbox at the periphery of the rotor. Also, in other embodiments, the HAWT turbine  100  may have more than two rotors. 
     In any of the embodiments described herein, the wind turbine  100  may be used to generate electrical energy for multiple applications. For example, the wind turbine  100  may be part of an electrical energy power plant, which generates electrical energy for a population, such as for a building (e.g., a household, an office, etc.), a village, or a city. Alternatively, the wind turbine  100  may be coupled to a machinery and is used to generate energy specifically for the machinery, such as an air-conditioner, a heater, a vehicle, etc. Thus, as used in this specification, the term “wind turbine” is not limited to energy generating devices that generate energy for multiple applications, and may refer to windmill, or a part of the windmill, that includes a specific machinery powered by wind power, or other energy generating devices that generate energy using wind power. It should be understood that the wind turbine  100  may be used to provide energy for anything (whether stationary objects or moving objects) that requires power. 
     In any of the embodiments described herein, the wind turbine  100  may be a DC wind turbine, an AC wind turbine, or other types of wind turbine. 
     It should be noted that the illustrated embodiments of wind turbine generators are for exemplary purposes only, and that they should not limit the scope of the claimed invention. 
     In the above embodiments, the wind turbine  100  has been described with reference to generating electrical energy using wind power. However, in other embodiments, the wind turbine  100  may be used to generate other types of energy using wind power. For example, in other embodiments, the wind turbine  100  may be used to generate heat energy, electromagnetic energy, or other types of energy. 
     Also, in any of the embodiments described herein, the wind turbine  100  may be utilized in air, on water, or on land. For example, embodiments of the wind turbine  100  may be incorporated as a part of a plane, a boat, or a land vehicle. In further embodiments, the turbine  100  may also be used in water. In such cases, instead of converting wind power to electrical energy, the turbine  100  converts fluid power to electrical energy. 
     Although particular embodiments have been shown and described, it will be understood that they are not intended to limit the present inventions, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present inventions. The specification and drawings are, accordingly, to be regarded in an illustrative rather than restrictive sense. The present inventions are intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the present inventions as defined by the claims.