Patent Application
20120019006
This disclosure is related to coaxial wind turbines.
A wind turbine converts the kinetic energy in wind into mechanical energy that is then converted by a generator into electricity. A coaxial wind turbine utilizes a second counter-rotating rotor to increase the amount of kinetic energy converted from a particular patch of sky.
For the purpose of promoting an understanding of the claims, reference will now be made to certain embodiments thereof and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure and the claims is thereby intended, such alterations, further modifications and further applications of the principles described herein being contemplated as would normally occur to one skilled in the art to which the disclosure relates. In several figures, where there are the same or similar elements, those elements are designated with the same or similar reference numerals.
In other embodiments, generators 70 and 72 can be remotely located with appropriate transmission between rotors 80 and 82 and generators 70 and 72.
Referring now to
Driver gear 112 is coupled to inner drive shaft 102 and driver gear 114 is coupled to outer drive shaft 104. Inner drive shaft 102 and outer drive shaft 104 are coupled to rotors 80 and 82. As such, inner drive shaft 102 and outer drive shaft 104 are counter-rotating. Driven gears 162 and 164 are positioned on opposite sides of inner drive shaft 102 and are engaged between driver gears 112 and 114. Counter rotation of driver gears 112 and 114 rotates driver gears 112 and 114 because the location where driver gear 112 engages each driven gear is phase shifted 180 degrees from the location where driver gear 114 engages each driven gear (the driver gears are located on opposing sides of the driven gears). This configuration permits both driver gears 112 and 114 to power rotation of the driven gears.
Driver gears 112 and 114 and driven gears 162 and 164 are beveled friction gears. In one embodiment, these beveled friction gears are constructed of a hardened steel material. In yet another embodiment, they may be constructed of a ceramic material. In other embodiments, other materials appropriate for friction gears may be utilized. In yet other embodiments, driver gears 112 and 114 and driven gears 162 and 164 are beveled gears with intermeshing teeth.
Output shafts 152 and 154 are coupled either directly or indirectly to generators 70 and 72. For example, in one embodiment output shafts 152 and 154 are directly coupled to generators 70 and 72. In this embodiment, generator 70 and 72 could be controllably engaged or disengaged with gear box 60 by moving driven gear 162 and/or 164 into or out of engagement with driven gears 162 and 164. As illustrated in
This configuration permits variations in the configuration of wind turbine 50. For example, because the power output from rotors 80 and 82 can be divided between multiple output shafts, generator 70 and 72 can be sized below the total output potential for wind turbine 50 permitting the use of comparatively smaller generators as compared to use of a single generator. In another embodiment, generator 70 and/or 72 can be optionally engaged to permit optimization of power output of wind turbine 50 for different wind conditions. For example, in comparatively lower speed wind operating conditions, one generator may be disengaged from gear box 70 permitting maximum power to the other generator. In comparatively higher wind speed operating conditions, generators 70 and 72 may be both engaged with gear box 60 to maximize the power output of wind turbine 50.
In other embodiments, additional output shafts may be added to increase this variable capacity beyond two generators. For example, additional output shafts and driven gears may be positioned at approximate perpendicular angle to output shafts 152 and 154 in a cruciform configuration. In other embodiments, housing 62 can be configured in other shapes (as viewed from the axis of drive shafts 102 and 104) such as hexagon, pentagon, octagon, decagon, etc., permitting the use of additional output shafts and the controllable engagement or disengagement of additional generators. As many output shafts as will fit between driver gears 112 and 114 may be used. In addition, the size of driver gears 112 and 114 can be varied to make space for additional output shafts.
In various embodiments, the number of output shafts are variable individually including having a single output shaft and driven gear coupled to driver gears 112 and 114.
Due to the friction coupling between driver gears 112 and 114 and driven gears 162 and 164, inner driver shaft 102 and outer driver shaft 104 will generally be constrained to revolve at approximately the same rotation speed which in turn generally constrains rotors 80 and 82 to revolve at the same speed.
In the illustrated embodiment rotors 80 and 82 are configured with two blades. In other embodiments, other rotor configurations can be three or four blades. Other embodiments can use any number of blades that may be desired for rotors 80 and 82. In one embodiment, rotor 82 may have a slightly increased surface area as compared to rotor 80 to more efficiently capture air flow that has been disrupted by rotor 80. In yet other embodiments, the comparative pitch between rotor 80 and rotor 82 may be varied. These embodiments may optimize performance with gear box 60 that generally constrains rotor 80 and rotor 82 to revolve at the same speed.
Referring now to
Support 220 is rotationally coupled to gear box 60 via inner drive shaft 210 and support 220 is rotationally coupled to gear box 60 via outer drive shaft 212. Inner drive shaft 210 and outer drive shaft 212 interface in gear box 60 in the same way that inner drive shaft 102 and outer drive shaft 104, described above, do. Gear box 60 and generators 70 and 72 are functionally the same as those described above with regard to
In the illustrated embodiment, rotors 230, 232, 234 and 236 are helically shaped members. Alternative embodiments can use other rotor configurations. In one embodiment, rotors 230, 232, 234 and 236 can be constructed of a solar cell membrane capable of converting light into electricity to augment the power production of vertical wind turbine 200.
In alternative embodiments, rotors 230 and 232 can be configured differently from rotors 234 and 236 to account for the disruption of the air flow by rotors 234 and 236 before encountering rotors 230 and 232 and also to account for differences in the distance from the center in which the rotors are mounted to achieve substantially equal angular velocities for supports 210 and 212.
While not illustrated, vertical wind turbine 200 can include structural supports. For example, additional horizontal supports can be located on top of rotors 230, 232, 234 and 236 to reduce deflection of individual rotors 230, 232, 234 and 236 in high wind conditions.
It should be understood that
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
The present application is a continuation of PCT/US2010/029610 filed Apr. 1, 2010, PCT/US2010/029610 claims the benefit of U.S. Provisional Patent Application Ser. No. 61/166,791 filed Apr. 6, 2009.
| Number | Date | Country | |
|---|---|---|---|
| 61166791 | Apr 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US2010/029610 | Apr 2010 | US |
| Child | 13252277 | US |
