1. Field of Invention
The present invention relates to wind turbines and, more particularly, to a vertical-axis wind turbine that is a sail wind turbine.
2. Description of Related Art
There is a need expressed to accommodate the populace of the planet With usable renewable electrical energy. For example, solar, wind, and geothermal power have been identified as energy sources that can be used to generate electricity. While some regions of the planet include vast sources of geothermal power, many regions of the planet are not as fortunate. Although solar and wind sources suffer from the problem of being intermittent in nature, recent advancements in technologies have made wind and solar energy an attractive and economically feasible solution to fulfill the deficiency in electrical power sources on the planet. Although solar energy may be an attractive renewable energy source, this application is directed to wind power.
For centuries wind power has been a source of energy and has been harnessed in various ways, with a clear distinction in the manner in Which wind energy is harnessed. In particular, there are horizontal-axis wind turbines and vertical-axis wind turbines.
In these modern times, the most common method for harnessing wind energy has been to use a horizontal-axis wind turbine. While horizontal-axis wind turbines have been promoted as being the more efficient type compared to other methods, they present several disadvantages. For example, horizontal-axis wind turbines have to be turned into the wind to start functioning. Also, they have a relatively high cut-in wind speed fur operation and a low cut-out wind speed. This allows fur only a relatively narrow window of operation, beyond which they are prone to damage. Another problem associated with the horizontal-axis design is that they typically require a gale force wind to produce power. Further, horizontal-axis wind turbines can be extremely high above a ground surface, making it difficult for technicians to perform much needed repairs. Due to such heights, technicians are largely exposed to grave risks as they provide maintenance service in adverse weather conditions.
As an alternative to the traditional wind turbine, vertical-axis wind turbines have been generated that change the axis of rotation of the turbine. The vertical-axis wind turbines improve the safety of servicing and maintenance duties as such services are performed much lower to the ground.
More specifically, in the 1920's, a French inventor by the name of Georges Jean Marie Darrieus designed a vertical-axis wind turbine that has been referred to as the “Darrieus design” or “eggbeater”. The Darrieus design uses a series of sails that are fixed at a set angle and arranged symmetrically around a vertical-axis. The symmetry of the sails provides a very effective means of generating a rotational force to the vertical shaft axis. Such vertical-axis wind turbines are used today on tall buildings to utilize the high wind velocity in higher altitudes. Unfortunately, sail fatigue, which causes premature failure of the system, is a common problem associated with the Darrieus design.
As an alternative to the Darrieus design, U.S. Pat. No. 4,449,053, issued to Kutcher, teaches a vertical-axis wind turbine that uses vertically positioned rotor blades. Blades are connected both at the top and bottom of a vertically extending rotor tube. While the Kutcher design does not includes sails that will fatigue, the vertically positioned rotor blades do easily capture wind at all angles, thereby reducing their effectiveness.
Another variation is the Giromill Cycloturbine, shown in U.S. Pat. No. 7,315,093, issued to Graham. The Giromill Cycloturbine has sails mounted such that the sails can rotate around an axis. The design of the Cycloturbine allows the sails to be pitched such that the sails are always at an angle relative to the wind. A main advantage to this design is that the torque generated remains almost constant over a fairly wide angle. Therefore, a Cycloturbine with three or four sails has a fairly constant torque. Predetermining the range of angles, the torque approaches a possible maximum torque, wherein the system generates more power. The system also has the advantage of being able to self start by pitching the down-wind moving sails flat to the wind to generate drag and start the turbine spinning at a low speed. One drawback to this design is that the sail pitching mechanism is complex and generally heavy, and a wind direction sensor must be added to the design in order to properly pitch the sails.
Currently, the commercial application of wind energy harnessing is primarily, if not exclusively, horizontal-axis wind turbines even though vertical-axis wind turbines avoid most of the disadvantages inherent in the horizontal-axis design. For example, vertical-axis wind turbines are omni-directional and have a lower cut-in wind speed and higher cut-out speed, thus making the window of operation wider. Also vertical-axis wind turbines have components that need servicing located at the bottom end of the structure making access more convenient. Vertical-axis wind turbines also allow for lower-ratio gearboxes, which are less expensive and more efficient than gearboxes needed to operate horizontal-axis wind turbines. Further, vertical axis wind turbines are able to operate at a higher wind speed and at lower risk of suffering wind damage. Finally, vertical-axis wind turbines adapt to a simpler design and construction.
Thus, there is a continuing need for a vertical-axis wind turbine that captures the inherent advantages of the vertical-axis design, yet improves upon the drawbacks of existing vertical-axis designs.
While considering the failure of others to make use of all of the above components in this technology space, the inventor unexpectedly realized that a vertical-axis wind turbine with sails that are pivotally attached to parallel and horizontal yardarms would provide an improved design without the drawbacks of the prior art.
Thus, the present invention is directed to a square rigged sail wind turbine that includes one or more stacked sail assemblies. Each sail assembly includes a main shaft having a vertical axis of rotation, with each successive sail assembly in the stack sharing the main shaft or otherwise having main shafts that are connected such that they share the vertical axis of rotation. Each sail assembly includes one or more yard arms that extend horizontally from the main shaft For example, a first set of horizontal and parallel yardarms extend from the main shaft. A first and second sail are connected with and between the yardarms. The sails are attached with the yardarms such that the main shaft is central and positioned between the sails.
A second set of parallel yardarms can be included that extend from the main shaft approximately perpendicularly to the first set of parallel yardarms. In this aspect, the second set of parallel yardarms also includes two sails connected between each of the yardarms. Thus, although not limited thereto, in this aspect, the first sail assembly includes four sails.
Support columns and lateral supports are included to connect with the vertical main shaft and for anchoring with a ground surface to support the main shaft in a vertical orientation. At the bottom of the wind turbine is a main deck. Ball-joint four roller thrust bearing are included for positioning on the main deck, with the main shaft passing therethrough. The thrust bearings provide stability to the main shaft and support weight of the sail assemblies. Roller bearings are also positioned through the main deck. The main shaft passes through the thrust bearings and roller bearings, leaving a shaft stem that extends below the main deck. The shaft stem passes through the bearings to provide the power take off to a power take off system.
In another aspect, the sail wind turbine system includes a wind tunnel having an entrance and an exit, with the wind turbine positioned within the wind tunnel between the entrance and the exit. En yet another aspect, roll-up and down doors are attached with the entrance and exit.
In yet another aspect, fencing is attached around the support columns.
In another aspect, four roll-up and down doors are attached with the support columns.
Finally, as can be appreciated by one in the art, the present invention also comprises a method for forming and using the wind turbine described herein.
The objects, features and advantages of the present invention will be apparent from the following detailed descriptions of the various aspects of the invention in conjunction with reference to the following drawings, where:
The present invention relates to wind turbines and, more particularly, to a vertical-axis wind turbine that is a square rigged sail wind turbine. The following description is presented to enable one of ordinary skill in the art to make and use the invention and to incorporate it in the context of particular applications. Various modifications as well as a variety of uses in different applications will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to a wide range of embodiments. Thus, the present invention is not intended to be limited to the embodiments presented, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
In the following detailed description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without necessarily being limited to these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.
The reader's attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All the features disclosed in this specification, (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is only one example of a generic series of equivalent or similar features.
Furthermore, any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. Section 112, Paragraph 6. In particular, the use of “step of” or “act of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. 112, Paragraph 6.
Please note, if used, the labels left, right, front, back, top, bottom, forward, reverse, clockwise and counter clockwise have been used for convenience purposes only and are not intended to imply any particular fixed direction. Instead, they are used to reflect relative locations and/or directions between various portions of an object.
The present invention is a vertical-axis wind turbine for generating electricity. In other words, the wind turbine is configured such that wind energy causes a series of sails to rotate about a vertical (or substantially vertical) axis. It should be understood that although the present invention is described with respect to wind and wind direction, it is not intended to be limited thereto as the turbine of the present invention can be also applied as a water-driven turbine with sails (or in the case of water, paddles) that are driven via a water current.
For an understanding of turbine construction and functionality,
Additionally and as shown in
It should be noted that although the sail assembly 100 depicted in
As a non-limiting example and as depicted in
Referring again to
For further understanding,
When the wind is active, four general stages take place, depicted as Stages A, B, C, and D, and further described as follows:
Adjusting the angle of pitch that the sails (e.g., square or rectangular sails) in the frames close and open from 90-degree open, to 45-degree closed, at the tip of the parallel and horizontal yardarms, stimulates an increased display of sail activity with a full-scale range of motion that improves the overall performance wind and in water.
It should be understood that the drawings display sails that open and close 90-degree at the tip of yardarms. The sails do actually open to 90-degree at the tip of parallel yardarms, but sails close only 45-degree, to quicken the action. It should also be understood that the degrees described herein are but one non-limiting example of suitable ranges of motion. For example, as can be understood by one skilled in the art, the ranges (i.e., degrees of motion) of the sails can move between any suitable ranges to provide wind capture and sail operation (cg., 42 degrees to 92 degrees, etc.).
The ability of the sail 110 to pivot about the sail pivot axis 111 allows the wind turbine to efficiently capture wind from any direction. Thus, the sails can adjust to function oppositely making rotation omni-directional, in any wind direction. As shown in
As noted above, the present invention can be employed to use a series of sails configured in a tiered fashion. For example,
The sails 110 are pivotally attached with the yardarms to open and close at the tip of parallel horizontal yardarms 104 and 106, demonstrating a continuity of order of sails in action. Each sail 110 relates to the next as they alternate in simultaneous succession against the force of wind pressure in down-wind, and up-wind. directions, respectively. The effect rotates a vertical main shaft 102, to bring about rpm power at ground level. Although illustrated with respect to only the first tier 401, it should be understand that the sails 110 in all tiers (e.g., 403, 405, and 407) include as lanyard 112 that is attached with a neighboring yardarm. It should also be understood that the main shaft 102 is obscured in the figure by a vertical support column 410.
As noted above, multiple tiers with multiple yardarms can be connected with the wind turbine to capture wind energy. For example,
The wind turbine 400 includes a main deck 402 that is used to stabilize the structure. A lower end of the vertical main shaft 102 goes through a bearing 404 to equalize stability and gravitate the exerting force revolving on the top surface of a main deck 402. The bearing 404 is any suitable mechanism or device capable of stabilizing the main shaft 102, a non-limiting example of which includes a ball-joint four-roller thrust bearing. The bottom end of the vertical main shaft 102 goes through main bearings 406, then through the center of the main deck 402.
As the main shaft 102 passes through main deck 402, it provides a rotating stem 500 that can be used for power take-off by a power take-off system. Thus, the sails 110 in their sail frames rotate the main shaft 102 to rotate a low, heavy massive base structure to mechanize the enhanced inertial effect.
In other words and as depicted in
As can be appreciated by one skilled in the art, there are alternative designs for the power take-off For example, although
As noted above, the present invention can include any suitable number of tiers of rotating sail frame structures. For example and referring again to
To further support the turbine 400, guy-wire can be attached with the structure. As a non-limiting example, a three-way guy-wire 506 can be attached in two places on each support column (e.g., 410 and 414), and then anchored to the ground to add support. It should be understood that the support columns can be secured to the base (footing) with or without guy-wires 506, depending on the desired stability and how high the support columns extend above a ground surface.
As yet another non-limiting example, the louvers 706 can be formed to rotate freely, with the exception of a stop that limits their rotation. For example, wind blowing against the louvers 706 will cause the louvers 706 to rotate within the sail frame 701 until they hit a stop. At which point, the louvers 706 are in a closed 710 position, which would cause the sail assembly to rotate. As the sail assembly rotates, at some point, the wind force against the louvers 706 is coming from a different direction, which blows the louvers 706 to an open 708 position. In the open position, the yardarm holding those louvers 706 is free to rotate past until wind catches the louvers 706 again and forces them into a closed 710 position.
A breaking system to stop rotation of the wind turbine will require all sails to remain in a closed position before the breaking system is applied. As a non-limiting example, a lanyard/stop control mechanism and counter can be included such that after an adequate number of rotations have been achieved before servicing, the lanyards or stops will then be moved to allow the sails to fully open. Once fully opened, the sails will not capture wind to act as a sail and, thus, the system will stop rotation.
As noted above, the present invention can be applied to any sail configuration. For example,
In another aspect, the turbine described herein can be a submerged turbine system to be used in an underwater current with a gearbox and generator assembly supported above water. Another aspect of the present invention includes a wind turbine assembly with louver type sails in frames that pivotal attach to parallel horizontal yardarms. In yet another aspect, the wind turbine system includes a floating barge, a gearbox connected to a generator and the wind turbine assembly that drives the gearbox.
Yet another aspect is depicted in
In another aspect and as illustrated in
Additionally as shown in
Further and as shown in
In another aspect and as shown in
In another aspect and as shown in
The wind tunnel 1402 can be constructed above ground or at ground level, with the wind tunnel 1402 open in the front and the rear. The wind tunnel 1402 can also house one or more wind turbines 1400 with fencing 17 to cover the front and the rear openings to keep out wildlife. Corrugated roll-up and down doors 1300 can also be attached at both the front and rear openings of the wind tunnel 1402 that can be closed during shutdown of the wind turbine/s 1400 for maintenance or other purposes.
It should be understood that the specific components described above are provides as a non-limiting example of suitable components and that the invention is not intended to be limited thereto. As a non-limiting example, although four support columns are described and illustrated, the invention can be formed with any desired number of support columns, which can be anchored to the ground with or without guy wires. Or as another example, in the event where a wind turbine is placed inside a wind tunnel, above ground or at ground level, the wind turbine system could be formed so that that are no guy wires attached to the wind turbine or support columns. Thus, as can be appreciated by one skilled in the art, the present invention can be modified with any combination of components to operate as described herein.
This is a Continuation-in-Part application of U.S. Ser. No. 13/010,553, filed on Jan. 20, 2011, entitled, “Square Rigged Sail Wind Turbine”, which is a non-provisional application of U.S. Provisional Application No. 61/297,460, filed on Jan. 22, 2010, and entitled, “Square Rigged Sail Wind Turbine.”
Number | Date | Country | |
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61297460 | Jan 2010 | US |
Number | Date | Country | |
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Parent | 13010553 | Jan 2011 | US |
Child | 14448419 | US |