Fluid reaction surfaces (i.e. – impellers) – Radially extensible or retractible rotor working member
Patent
1990-02-02
1991-07-02
Look, Edward K.
Fluid reaction surfaces (i.e., impellers)
Radially extensible or retractible rotor working member
416131, 416132B, 416135, 416141, F03D 0704
Patent
active
050282093
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention concerns a wind power plant construction.
In existing wind power plants the blades of the turbines are fixed comparatively firmly to the shaft so that the turbine can withstand the torques and other stresses even from powerful gusts of wind. This means that adjustment of the turbine blades is made afterwards, that is after the effect of wind on the turbine has been observed, or no blade adjustment whatsoever is undertaken and the turbine is instead controlled with brakes. Such structural designs involve heavy and expensive blade structures, with the consequence that the supporting and bearing arrangements are also required to possess very high durability.
The object of the invention is elimination of the drawbacks mentioned. The specific object of the invention is to provide a wind power plant construction which automatically and continously adjusts the blades in accordance with wind strength and load variations so that the powerful, varying stress-imposing forces caused e.g. by gusts are attenuated before being transmitted to the structures. It is likewise an object of the invention to provide a turbine design which is light and favourable in manufacturing cost, enabling a wind power plant to be constructed which has a good energy production/price ratio.
SUMMARY OF THE INVENTION
The power plant construction of the invention comprises a turbine having at least two blades, with shaft and blade angle control means. As taught by the invention, to a fixing hub attached to the shaft is rigidly connected for each blade a radial brace substantially radial relative to the shaft, on its extreme end carrying a flapping pivot, advantageously a ball joint, to which the blade is substantially affixed. The flapping pivot takes up those centrifugal and gravity forces acting on the blades which are produced in operation and transmits from the blade the reaction forces paralleling the turbine shaft and the plane of rotation, and serves as point of support and bearing for the torques acting about the axis of rotation of the blade. It also permits changes of the angle of the blade's axis of rotation relative to turbine shaft and plane of rotation. Furthermore, according to the invention the blade extends from the flapping pivot towards the shaft, thus forming an arm to which a control rod associated with the blade angle control means is connected with the aid of a pivot, and a rotation support for the blade root, located on the axis of rotation of the blade. The blade moreover comprises separate weights, or its design has been so arranged that the centroid line of the blade lies forward of the aerodynamic centre of the blade, i.e., on the leading edge side, the axis of rotation passing through the blade pivot lying forward of the buoyancy centre of the blade profile, i.e., on the leading edge side.
The advantage of the invention over the state of art consists of the fast and accurate control characteristics of the device, which enable structures to be employed which are substantially lighter, and at the same time less expensive, than any existing blade, pivot, bearing and support structures because large force variations, which stress the structures, have been eliminated by means of continuous and accurate control.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in detail in the following, reference being made to the attached drawings, wherein:
FIG. 1 presents, viewed in axial direction, a blade and turbine centre design according to the invention,
FIG. 2 presents the blade construction of FIG. 1, in elevational view,
FIG. 3 presents part of the control means of the invention,
FIG. 4 presents part of the control means of the invention, and
FIG. 5 shows the section along the line 5--5 in FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, presenting a wind power plant construction according to the invention, this construction comprises three hard-shelled turbine blades 1 having an airfoil-shaped cross section and their centroid coincidin
REFERENCES:
patent: 191168 (1877-05-01), Nesbitt
patent: 192931 (1877-07-01), Palmer
patent: 302285 (1884-07-01), Russell
patent: 603806 (1898-05-01), Zwiebel
patent: 2247929 (1941-07-01), Terhune
patent: 2464234 (1949-03-01), Jocobs
patent: 4087202 (1978-05-01), Musgrove
patent: 4299537 (1981-11-01), Evans
patent: 4310284 (1982-01-01), Randolph
patent: 4799860 (1989-01-01), Martin
Larson James A.
Look Edward K.
LandOfFree
Wind power plant construction does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Wind power plant construction, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Wind power plant construction will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1243287