Abstract
What is disclosed is a vertical-axis wind turbine that looks somewhat similar to a vertical pole during no-wind or relatively low-wind conditions, i.e., when the turbine is waiting for relatively windy conditions, and that transitions between its waiting state and wind harnessing state automatically. Yet, to automatically transition between states, the turbine uses relatively few moving mechanical assemblies and uses no electric parts. The turbine has levers attached radially to a vertical mast and one or more wings attached to each lever. Each wing's mounting angle causes the wing to move the lever to which it is attached to deploy the wing(s) attached to that lever to rotate the mast. At an approximate rotation point of the mast, to avoid the deployed wing(s) from unduly opposing the mast's rotation, the wing's angle facilitates the retraction of the wing(s). The net drag of the wing(s) serves to rotate the mast.
Claims
1. A vertical-axis wind-energy-conversion system (VAWECS) comprising: a central vertical mast; a plurality of axles, hinges, or pivots connected radially to the central vertical mast so that each axle's, hinge's, or pivot's axis of rotation is perpendicular or roughly perpendicular to the central vertical mast's axis of rotation; a plurality of lever arms where each lever arm is connected to a said axle, hinge, or pivot, a plurality of wings where each wing is mounted on a said lever arm so that the majority of the wing or the entire wing is on one side of the lever arm's axle, hinge, or pivot to form an assembly of the wing and lever arm (such that the mass of the assembly's portion to one side of the assembly's axle, hinge, or pivot is greater than the mass of the assembly's portion to the opposite side of the assembly's axle, hinge, or pivot) and where the wing has a camber and when the assembly of the wing and lever arm is oriented so that the lever arm is generally perpendicular to the vertical mast the wing's positive-camber (convex) side generally faces toward a desired rotational direction of the central vertical mast and the wing's edge furthest from the central vertical mast is tilted, about the longitudinal axis of the lever arm, toward the desired rotational direction of the central vertical mast.
2. The VAWECS of claim 1 further comprising a plurality of opening angle limiters (e.g., straps, link assemblies) where each lever arm has a said limiter connecting the lever arm to the central vertical mast.
3. The VAWECS of claim 1 further comprising a plurality of backstops where a said backstop for each lever arm is mounted on the central vertical mast generally on or near the longitudinal line of the vertical mast passing through the point at which the lever arm's axle, hinge, or pivot meets the central vertical mast so that the lever arm is rotationally in front of the backstop with respect to the rotation of the lever arm about the lever arm's axle, hinge, or pivot in the same general direction to which the convex side of the lever arm's wing is facing.
4. The VAWECS of claim 1 further comprising a plurality of backstops where a backstop for each lever arm is integrated into the said lever arm's axle or hinge.
5. The VAWECS of claim 1 further comprising a plurality of opening angle stops where an opening angle stop for each lever arm is integrated into the said lever arm's axle, hinge, or pivot.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0052] The drawings show features of an exemplative embodiment of the present invention.
[0053] FIG. 1 shows from slightly above and at an angle an embodiment when wind has lifted a wing to the highest point allowed by a tangle-free strap.
[0054] FIG. 2 shows the top portion of an embodiment from the side when there is no or little wind.
[0055] FIG. 3 shows the embodiment and state featured in FIG. 2 from the perspective of being above the embodiment.
[0056] FIG. 4 shows an example of a mounting angle of a wing in an embodiment as mounted on a lever arm. The figure shows the lever arm as viewed along the lever arm's longitudinal axis from the end of the lever arm that is nearest to where the wing is mounted.
[0057] FIG. 5 shows the embodiment and state featured in FIG. 4 when the central vertical mast has rotated an axle into the wind which is nearing the rotation point about the central vertical mast where the wing begins to rotate about the axle the lever arm to which the wing and axle are attached.
[0058] FIG. 6 and FIG. 7 show a wing's approximate earliest deployment and latest retraction rotational points, respectively, in order to facilitate rotation of the central vertical mast counter-clockwise as viewed from the top.
DETAILED DESCRIPTION OF THE INVENTION
[0059] Described in this section is an exemplificative embodiment of the present invention.
[0060] FIG. 1 shows from slightly above and at an angle an embodiment of the device having connected to its central vertical mast (100) three axles (e.g., 1) arranged radially around the central vertical mast (100). To each axle (1) is connected a lever arm (110). Connected to each lever arm (110) is a wing (112). A wing (112) is shown in FIG. 1 lifted by wind to the highest point allowed by a tangle-free strap (105). The wing (112) is attached to a lever arm (110) that is attached to an axle (1) which is attached to the central vertical mast (100). Attached to the central vertical mast is an eyebolt (104) that is attached to said tangle-free strap (105) that is attached to another eyebolt (106) that is attached to said lever arm (110). Attached to the central vertical mast (100) is a backstop (114), which prevents the said lever arm (110) from rotating about its axle past the said backstop (114) when gravity causes the wing (112) to move toward the ground. Gravity may be stronger than the lifting forces caused by the wind when, for example, the wind has subsided or when the central vertical mast (100) has rotated the axle (1) so that the wing (112) attached to the said axle (1) via the lever arm (110) is plunging into wind.
[0061] A no- or low-wind condition is shown in FIG. 2 and FIG. 3. FIG. 2 shows the top of the embodiment from the side, where each of the three lever arms (e.g., 100) is in the neutral position. In other words, gravity has pulled each wing (112) to the lowest point allowed by the structure of the embodiment.
[0062] From directly above the embodiment, FIG. 3 shows the embodiment. Each wing (112) is curved and oriented in a fashion similar to that used in a Savonius-type vertical axis turbine to help rotate the central vertical mast (100) counter-clockwise, as viewed from above.
[0063] Each wing (112) has a non-zero mounting angle with respect to the axle (1) to which the wing is attached via a lever arm. FIG. 4 shows a wing (112) having a mounting angle (as represented by the Greek letter ) as viewed along the lever arm's longitudinal axis from the end of the lever arm that is nearest to where the wing is mounted (7) when the lever arm is in the neutral position. That is, FIG. 4 is showing a subset of the embodiment as viewed from the bottom of the embodiment when the lever arm in that subset is generally parallel to the central vertical mast (100) and when the length of the lever arm having the wing attached is closer to the ground than the opposite length of the lever arm as bifurcated by the lever arm's axle (1). The wing's lateral axis (400) is oriented away from the axle's longitudinal axis (402) to a degree represented by the measure the angle between the two axes () and is oriented toward the central vertical mast's desired rotational direction (116). Because the perspective of FIG. 4 is from the ground, the central vertical mast's desired rotational direction (116) is shown to be clockwise in FIG. 4.
[0064] From the same viewing perspective used in FIG. 4, FIG. 5 shows the embodiment and state featured in FIG. 4 when the central vertical mast has rotated an axle into the wind (the direction that the wind is moving is indicated by the direction to which the arrows referenced by 204 are pointing) which is nearing the rotation point about the central vertical mast (100) where the wind begins to lift the wing (112) so that the lever arm begins to rotate about the axle to which the lever arm is attached in the direction indicated by the arrow indicated by reference 404 in FIG. 5.
[0065] Those skilled in the art of wing design are able to choose the mounting angle of the wing (0) so that the wind tends to lift the wing when the lifting of the wing would help rotate the central vertical mast counter-clockwise as viewed from above the embodiment. Such a time is approximately shown in FIG. 6. FIG. 6 shows from above the embodiment an approximate point within the windward side of the embodiment (202) where an axle (1) has rotated such that when the wing to which it is attached deploys. That is, the wind (204) lifts the wing. That deployment point is selected so that the deployed wing is mostly on the right-hand side of the central vertical mast when viewed from above the mast. On the right-hand side of the central vertical mast, the wing's drag tends to rotate the mast in the desired rotational direction (116), counter-clockwise as viewed from above the central vertical mast.
[0066] FIG. 7 shows the axle (1) approaching the leeward side (200) of the embodiment. If the wing were to remain deployed as the axle (1) rotates into the leeward side (200) of the embodiment, the wind's drag on the deployed wing would tend to resist the central vertical mast's counter-clockwise rotation. To help reduce that resistance, those skilled in the art of wing design could choose the mounting angle of the wing () and other parameters of the wing so that gravity would tend to retract the wing before the point where if the wing were to remain deployed, the wing would tend to unduly resist the central vertical mast's counter-clockwise rotation (as viewed from above the central vertical mast).
[0067] In order for a deployed wing to facilitate the central vertical mast's desired rotation, the wing should not be in a deployed state when the axle of the lever arm to which the wing is attached is on the leeward side of the central vertical mast in this embodiment. The leeward side can be described by the portion of this embodiment that is in the leeward half-circle referenced by the number 200 in FIGS. 4, 5, 9, and 10. Thus, in those figures, the sets of vertical arrows referenced by the number 204 point toward the wind's destination.
[0068] Within the windward side (202) of the central vertical mast, there is a region that when the axle of a lever arm is in that region, the act of deploying the wind attached to the lever arm (110) helps to rotate the central vertical mast counter-clockwise (as viewed from above the central vertical mast).
[0069] FIG. 6 shows an axle (1) at a location where that region approximately begins. The wing may remain deployed until the rotation of the central vertical mast causes the wing's drag to start to oppose the counter-clockwise rotation of the central vertical mast (as viewed from above the central vertical mast). The central vertical mast is shown nearing or approximately at that state of rotation in FIG. 7.
Weathering Hurricane-Strength Winds
[0070] Those skilled in the art of modeling forces, material strength, and wing design could most likely design an embodiment to deploy two opposing lever arms simultaneously to slow the rotation of the central vertical mast.
