Turbine system with lift-producing blades

Abstract

A fluid and wind turbine system suitable for horizontal or vertical axis applications comprising (i) blades radially spaced around a rotational axis attached to a shaft by mounting formations so that the length axis of the mounting formations are substantially parallel to the width axis of the blades which mounting formations suspend the blades from the rotational axis creating a passageway allowing the air flow to pass through the turbine and impart a unidirectional rotational force to the shaft at all times the blades are exposed to the air flow on both the windward and leeward sides of the rotational axis (ii) an air flow director which shields the rotating blades from the air flow for a portion of their 360-degree rotation.

What is claimed is: 
     
         1 . A turbine system comprising:
 a shaft configured to rotate about a rotational axis;   a plurality of blades coupled to the shaft, wherein the blades are oriented with the width (chord) axis of the blades aligned in a radial direction away from the rotational axis, and wherein the blades are configured to provide lift according to the Bernoulli principle resulting from lower pressure on convex first blade sides of the blades exposed to air flow than on second blade sides of the blades exposed to the air flow, when fluid passes on both sides of the blades, the lift provided in the direction of rotation through portions of the rotation of the blades about the rotational axis on both the windward and leeward sides of the rotational axis;   mounting formations which attach the blades to the shaft and suspend the blades away from the shaft, with air flow passages defined between the shaft and the blades; and   an air flow director with a convex outer surface on the windward side of the rotational axis configured to expose the blades to air flow through a first part of rotation of the blades about the rotational axis, and to block air flow to the blades through a second part of the rotation of the blades about the rotational axis;   wherein the air flow director is configured and oriented to direct the air flow in part through the air flow passages defined between the shaft and the blades;   wherein the air flow director with the convex outer surface on the windward side of the rotational axis, has one edge that is parallel to leading edges of the blades as the blades emerge from the air flow director to encounter the air flow;   wherein the windward air flow director is positioned such that a straight line drawn away from the convex surface of the air flow director perpendicular to any tangent of the convex surface of the air flow director will not intersect the convex surfaces of the blades at any time the blades are moving on the windward side of the rotational axis; and   wherein the air flow director with the convex outer surface exposed to the air flow on the windward side of the rotational axis is configured so that when the blades are moving on the windward side of the rotational axis, a straight line perpendicular to the chord line of any blade will intersect the convex outer surface of the air flow director on the windward side of the rotational axis.   
     
     
         2 . The turbine system of  claim 1 , wherein the air flow director has curved channeling flow diverters aligned with convex surfaces facing the vertical centerline of the air flow diverter mounted on an external surface of the air flow director, for diverting air flow toward the blades. 
     
     
         3 . The turbine system of  claim 1 , wherein the air flow director has a portion located on the leeward side of the blades. 
     
     
         4 . The turbine system of  claim 3 , wherein the air flow director further has exhaust passages in the portion of the air flow director which is located leeward of the blades. 
     
     
         5 . The turbine system of  claim 3 , wherein the air flow director is configured to accelerate the air flow as the air flow flows over a windward part of the air flow director and to direct the accelerated air flow through air flow passages defined between the shaft and the blades, and then the air flow director returns the air flow to an original direction of the air flow as the air flow travels over a leeward part of the air flow director. 
     
     
         6 . The turbine system of  claim 1 , wherein the air flow director defines side passages that allow air flow to exhaust from the area encompassed by an inner surface of the air flow director which is not exposed to the air flow. 
     
     
         7 . The turbine system of  claim 1 ,
 wherein the blades each have a leading edge, proximal to the rotational axis, and a trailing edge, distal to the rotational axis; and   wherein for each of the blades a chord line of the blade from the leading edge to the trailing edge intersects with the rotational axis.   
     
     
         8 . The turbine system of  claim 1 , wherein the blades each are configured to provide positive Bernoulli principle lift on a windward side of the shaft, tending to pull the blades into the air flow, and negative Bernoulli principle lift on a leeward side of the shaft, tending to push the blades out of the air flow. 
     
     
         9 . The turbine system of  claim 1 , further comprising a generator that converts rotational energy to electrical or mechanical energy, wherein the generator is operatively connected with the shaft. 
     
     
         10 . The turbine system of  claim 1  further comprising a platform configured for rotation on an axis such that the blades exposed to the air flow are aligned with the direction of the air flow. 
     
     
         11 . The turbine system of  claim 10  wherein the platform is buoyant. 
     
     
         12 . The turbine system of  claim 1 , further comprising a buoyant platform connected by a tether to a fixed mount, allowing the platform to float downwind of the air flow. 
     
     
         13 . The turbine system of  claim 1  wherein the turbine system is in combination with tethers used to mount the turbine system to a supporting structure. 
     
     
         14 . The turbine system of  claim 1  wherein the turbine is mounted on the top and/or side of a building. 
     
     
         15 . The turbine system of  claim 1  wherein the turbine is positioned with a vertical rotational axis and is mounted on a turntable or is otherwise enabled to rotate on a pedestal. 
     
     
         16 . The turbine system of  claim 1 , wherein the air flow director has a convex outer surface exposed to the air flow, and an opposite, flat surface mounted on the earth or afloat that is not exposed to the air flow. 
     
     
         17 . The turbine system of  claim 1 , wherein the air flow director is configured to form a single continuous airfoil windward of the blades, and leeward of the blades. 
     
     
         18 . The turbine system of  claim 1 , wherein the second blade sides are non-convex. 
     
     
         19 . The turbine system of  claim 18 , wherein the second blade sides are concave. 
     
     
         20 . The turbine system of  claim 18 , wherein the second blade sides are flat. 
     
     
         21 . The turbine system of  claim 1 , wherein the blades are symmetrical in cross section. 
     
     
         22 . The turbine system of  claim 1 , wherein the blades each have a symmetric thickness in the width direction about a midpoint along the chord line, being thickest at the midpoint along the chord line between a leading edge and a trailing edge, and thinner at the leading edge and the trailing edge than they are between the leading edge and the trailing edge. 
     
     
         23 . A turbine system comprising:
 a shaft configured to rotate about a rotational axis;   a plurality of blades coupled to the shaft, wherein the blades are oriented with the width (chord) axis of the blades aligned in a radial direction away from the rotational axis;   mounting formations which attach the blades to the shaft and suspend the blades away from the shaft, defining air flow passages between the shaft and the blades so that when the blades are exposed to the air flow on the windward side of the rotational axis, the air flow can pass from a leading edge of the blades to a trailing edge of the blades, and when the blades are exposed to the air flow on the leeward side of the rotational axis, the air flow is reversed with respect to the blades so the air flow travels from the former trailing edge of the blades toward the former leading edge of the blades;   wherein each of the blades has positive camber scribing an arc less than a semicircle when viewed in cross section, with a mean camber line closer than a chord line to a convex first side of the blade, the first side of the blade being opposite to a second side of the blade, with the first side and the second side both exposed to the air flow;   wherein the convex first blade sides exposed to the air flow are more convex than the second blade sides exposed to the airflow;   wherein the blades are configured to provide lift according to the Bernoulli principle resulting from lower pressure on the convex first blade sides of the blades exposed to air flow than on the second blade sides of the blades exposed to the air flow, when fluid passes on both sides of the blades; wherein the blades are configured so that when the blades are exposed to the air flow, the lift is provided by the blades both when the air flow moves from a leading edge to a trailing edge of the blade and also lift is also provided when the air flow is reversed with respect to the blades so the air flow moves from such trailing edge to such leading edge of such blades, the lift being provided in the direction of rotation on both the windward and leeward sides of the rotational axis; and   an air flow director configured to expose the blades to air flow through a first part of rotation of the blades about the rotational axis, and to block air flow to the blades through a second part of the rotation of the blades about the rotational axis; and   wherein the air flow director is configured and oriented on the windward side of the rotational axis to accelerate the air flow along a convex outer surface of the air flow director toward the blades and then, before the air flow encounters the blades, the air flow director is configured to direct the air flow to a direction parallel to the direction the air flow was traveling before the air flow encountered the air flow director.   
     
     
         24 . The turbine system of  claim 23 , wherein the blades are symmetrical in cross section. 
     
     
         25 . The turbine system of  claim 23 , wherein the blades each have a symmetric thickness in the width direction about a midpoint along the chord line, being thickest at the midpoint along the chord line between a leading edge and a trailing edge, and thinner at the leading edge and the trailing edge than they are between the leading edge and the trailing edge. 
     
     
         26 . The turbine system of  claim 23 ,
 wherein the blades each have a leading edge, proximal to the rotational axis, and a trailing edge, distal to the rotational axis; and   wherein for each of the blades a chord line of the blade from the leading edge to the trailing edge intersects with the rotational axis.   
     
     
         27 . The turbine system of  claim 23 , wherein the blades each are configured to provide positive Bernoulli principle lift on a windward side of the shaft, tending to pull the blades into the air flow, and negative Bernoulli principle lift on a leeward side of the shaft, tending to push the blades out of the air flow. 
     
     
         28 . The turbine system of  claim 23 , wherein the second blade sides are non-convex. 
     
     
         29 . The turbine system of  claim 28 , wherein the second blade sides are concave. 
     
     
         30 . The turbine system of  claim 28 , wherein the second blade sides are flat. 
     
     
         31 . The turbine system of  claim 23 , wherein the air flow director is positioned on a windward side of the blades. 
     
     
         32 . The turbine system of  claim 31 , wherein the air flow director has curved channeling flow diverters aligned with convex surfaces facing the vertical centerline of the air flow diverter mounted on an external surface of the air flow director, for diverting air flow toward the blades. 
     
     
         33 . The turbine system of  claim 31 , wherein the air flow director has a portion located on the leeward side of the blades. 
     
     
         34 . The turbine system of  claim 33 , wherein the air flow director is configured to accelerate the air flow as the air flow flows over a windward part of the air flow director and to direct the accelerated air flow through air flow passages defined between the shaft and the blades, and then the air flow director returns the air flow to an original direction of the air flow as the air flow travels over a leeward part of the air flow director. 
     
     
         35 . The turbine system of  claim 23 , wherein the air flow director has a portion located on the windward side of the blades and also a portion located on the leeward side of the blades. 
     
     
         36 . The turbine system of  claim 35 , wherein the air flow director further has exhaust passages in the portion of the air flow director which is located leeward of the blades. 
     
     
         37 . The turbine system of  claim 23 , wherein the air flow director defines side passages that allow air flow to exhaust from the area encompassed by an inner surface of the air flow director which is not exposed to the air flow. 
     
     
         38 . The turbine system of  claim 23 , further comprising a generator that converts rotational energy to electrical or mechanical energy, wherein the generator is operatively connected with the shaft. 
     
     
         39 . The turbine system of  claim 23 , further comprising a platform configured for rotation on an axis such that the blades exposed to the air flow are aligned with the direction of the air flow. 
     
     
         40 . The turbine system of  claim 39 , wherein the platform is buoyant. 
     
     
         41 . The turbine system of  claim 23 , further comprising a buoyant platform connected by a tether to a fixed mount allowing the platform to float downwind of the air flow. 
     
     
         42 . The turbine system of  claim 23 , wherein the turbine system is in combination with tethers used to mount the turbine system to a supporting structure. 
     
     
         43 . The turbine system of  claim 23 , wherein the turbine is mounted on the top and/or side of a building. 
     
     
         44 . The turbine system of  claim 23 , wherein the turbine is positioned with a vertical rotational axis and is mounted on a turntable or is otherwise enabled to rotate on a pedestal. 
     
     
         45 . The turbine system of  claim 23 , wherein the air flow director has a convex outer surface exposed to the air flow, and an opposite, flat surface mounted on the earth or afloat that is not exposed to the air flow. 
     
     
         46 . The turbine system of  claim 23 , an air flow director configured to form a single continuous airfoil windward of the blades, and leeward of the blades.