Abstract: A wind turbine adapted to rotationally drive a load such as an electric power generator 50 includes in the turbine drive train, resiliently mounted gearing 55 which isolates and damps the load from drive train disturbances caused by wind gusts and wind stream dyssemmetry and inherent torsional vibration without assistance from modulation of turbine blade pitch.
Abstract: There is disclosed in the present application a wind wheel having a set of movable vanes whose orientation with respect to the plane of the wheel is changed automatically to limit the speed to a safe level in winds of high velocity. The wheel is constructed and shipped in segments and is especially adapted for ease of assembly and truing for minimal eccentricity and lateral run-out.
Abstract: A wind-driven turbine with a self-regulating pitch control system is disclosed. The turbine includes a wheel having a plurality of wings or blades that rotate about a longitudinal pivot axis through a pitch range. The blades are in coned or parallel relation to the axis of rotation of the wheel. Biasing means are provided for biasing the wings toward a starting pitch position. The center of gravity of each wing is spaced from the axis of rotation of the wheel and from the pivot axis of the wing toward its trailing edge. Centrifugal force acting on the wings causes them to move from a starting pitch orientation to a power pitch orientation as the speed of the turbine increases. A system is provided for selectively controlling the pitch of the wings, preferably from a location remote from the turbine.
Abstract: A propeller hub carries pivotally-mounted blades that are linked to a spring-loaded collar on the propeller shaft for automatic coning and feathering under predetermined high velocity movement along the propeller shaft to change the blade pitch angle during low wind velocity conditions. An airfoil support mounts a propeller shaft and turns therewith to reduce tower shadow effects. This is called a "down-wind system" meaning the propeller is behind the tower and causes the assembly to rotate into the wind without a tail vane.
Abstract: An improved wind turbine in which the tip portions of the blades are variable in pitch and are cyclically varied in pitch to control the yaw of the rotor and to relieve bending moments on the blades and are collectively varied in pitch to relieve bending moments on the blades and to maximize the power output of the turbine at a selected constant rotor speed.
Abstract: A wind powered electrical generator having a rotatable wind wheel (21) carrying one of the armature (42) or field structures and a plurality of windvanes (45) connecting the rim to a central shaft (28), a stator (39) carrying the other of the armature or field structures, and a supporting structure (22) for the windwheel rotor shaft and the stator. The armature winding is carried by the windwheel at its perimeter, and the field structure is a ring structure which lies just radially outward of the armature winding and is carried by the fixed housing structure which perimetrally surrounds the windwheel. Bearing support (48) provided at the perimeter of the windwheel by low friction bearings carried by the fixed housing structure minimizes bearing stresses developed at the supporting shaft under wind loading conditions.
Abstract: A speed control system for a windmill having blades which can be feathered for altering speed and with the blades under the control of a mechanism which includes a piston assembly and a fluid governor associated therewith. Spring means are used to feather the blades against the force of the piston assembly which is interconnected with the blades, and the speed of blade rotation actually creates the fluid pressure acting on the piston assembly and a governor is associated with the piston assembly for controlling the position of the piston and thus controlling the feathering of the blades, all according to the speed of rotation of the windmill blades. The windmill can be used for generating electric power, and fail-safe mechanisms are employed for protecting in the event of a windmill blade breakage.
Abstract: A multi-vane windmill rotating in a horizontal plane on a vertical shaft includes frame supported fabric type vanes with the frame hingedly attached at one end to support arms to swing closed and catch the wind in one position and to swing open under centrifugal and wind forces in another position when coming into the wind to reduce air resistance. Vanes are releasably attached in part to the frame for support in operating position and otherwise slidably secured thereto so as to release and collapse on the frame under extreme wind pressures when the frame is closed and thus spill the wind. Stops on the support arms provide a limit of movment of the vane frames. A second embodiment of the vanes includes two overlapping sections normally held in overlapped or closed position by yielding means that permit the sections to separate under high winds to provide an air passageway through the vane.
Abstract: A base is provided and a rotor is journaled from the base for rotation about a first upstanding axis. The rotor includes a plurality of vanes journaled therefrom for rotation about second axis spaced about and radially outwardly from the first axis and vane displacement control structure is operatively connected between the base and the vanes for proportionally angularly displacing the vanes relative to the rotor 180.degree. in one direction during each 360.degree. of rotation of the rotor in the opposite direction. The vanes are angularly displaced in optimum positions relative to the rotor and each other to develop maximum thrust by the vanes on the rotor responsive to fluid flow against the vanes from a predetermined side of the first axis.
Abstract: Windmill apparatus comprises an open framework defining a wheel having means defining a pivot axis and embodying a plurality of radially and closely spaced concentric rows of air foils. The foils in each row are connected for their conjoint movement to and from a pre-set operating position, within defined limits. The movement of each foil is about an axis which is substantially radial to the wheel and it is arranged to automatically feather when subject to impact of winds the speed of which is at a dangerous level. As oriented in the wheel the radial extremities of each foil are substantially flat and bridged by a continuous peripheral surface portion. One portion of said peripheral surface portion is flatted to define the operating face of the foil. The flatted portion is preferably comprised of two planar surface portions one of which leads the other, having regard for the facing of the foil operating surface into the prevailing wind.
Abstract: A reaction-type turbine provided with an output shaft coupled to a power generator, such as an electric generator, and having a plurality of variable-pitch flexible impeller blades, or sails, mounted between the periphery of the output shaft and a concentric tubular shroud rotatable in unison with the output shaft. The pitch of the flexible impeller blades or sails is varied by a centrifugally-actuated pitch controlling unit such that the output shaft has a constant angular velocity irrespective of variations in the velocity of the fluid flowing through the turbine. For actuation by wind, the turbine is mounted on a rotatable platform which is automatically oriented in the direction of the prevalent wind by a servo system controlled by a wind direction detecting device. The mass of air flowing through the turbine is automatically controlled as a function of the wind velocity by an appropriate throttling mechanism controlled by a wind velocity detector.
Abstract: A windmill of the vertical axis type having a plurality of circumferentially-spaced rotatably-mounted vanes wherein means are provided for controlling the feathering of the vanes so that, upon feathering they rotate in a direction opposite to that rotation of the windmill assembly, wherein means are provided to assure that the entire assembly heads up into the wind, and wherein means are provided for disengaging of the entire vane assembly when the wind velocity reaches a predetermined value.
Abstract: A power generating system includes a wind turbine driven generator, the wind turbine having a wind turbine driven rotor with a variable pitch angle blade. Stresses on the system during startup and shutdown are minimized by scheduling the blade angle as a function of the rotor speed and wind velocity to provide a minimum blade angle relative to the fully powered blade angle during rotor acceleration, and to provide a minimum blade angle relative to the fully powered blade angle during rotor deceleration.
Abstract: A system of rotatably and pivotally mounted radially extended bent supports for radially extending windmill rotor vanes in combination with axially movable radially extended control struts connected to the vanes with semi-automatic and automatic torque and other sensing and servo units provide automatic adjustment of the windmill vanes relative to their axes of rotation to produce mechanical output at constant torque or at constant speed or electrical quantities dependent thereon.
Abstract: A spring-loaded pivoting end plate that is hinged such that it is deployed by centrifugal force into the airstream to thereby act as an aerodynamic brake for wind turbines in overspeed conditions. The brake has a stationary portion fixed on the tip of the turbine rotor and a pivoting portion hinged for movement with respect to the fixed portion. The longitudinal centerline of the brake coincides with the chord line of the turbine blade and the pivoting movement is about a hinge axis that is normal to the rotational plane of the turbine. The planform of the brake has a low aspect ratio shape with the ratio of the fore and aft chordwise length to the width being one or greater. The edges of the brake in the normal running condition extend beyond the contour of the turbine blade to serve as an end plate such that the aerodynamic efficiency of the blade is improved thereby.
Abstract: A conical shaped rotor is described for rotation about a horizontal shaft axis for responding to or creating a moving airstream. The rotor is elongated and conical shaped along the rotor axis with elongated blades extending longitudinally and radially inward from an enlarged end to a reduced end. The blades are angularly offset between 1.degree. and 15.degree. from the rotor axis to cause an inner side edge of each blade to be closer to the rotor axis than an outer side edge without the blades being twisted about their longitudinal axis. In one form an electrical generator is operatively attached to the rotor shaft for generating electrical energy in response to the rotation of the rotor by wind passing therethrough. In a second form the rotor is driven by a motor to create an air flow therethrough to serve as a fan.
Abstract: A windmill with a vertical-axis rotor having thrust vanes which is surrounded by a stationary cage having guide vanes to channel the windstream to the rotor. In the preferred embodiment the rotor is a flow-through type with airfoil vanes.
Abstract: Mounted on a vertical axis there is a horizontal axis and, vertically spaced therefrom, a wind wheel generator and counterweight unit. When the wind speed exceeds a predetermined limit, the unit is swung thereby, in a vertical plane, decreasing the effect of the wind on the wheel and protecting it from overload.
Abstract: The disclosed wind turbine has zero mean camber airfoil blades vertically pivoted at the outer ends of pairs of radius arms. The inner ends of the radius arms are fixed to a rotating mast. Each blade is provided with a steering vane. The deflection of each vane with respect to its associated blade is controlled by a cam toggle mechanism. The disclosed cam toggle mechanism includes a double-faced face cam, having a closed cam track on its upper face and another closed cam track on its lower face. Each cam track consists of two circular dwell portions.
November 5, 1976
Date of Patent:
January 30, 1979
Board of Regents University of Nevada System
Abstract: A wind driven power plant for the generation of electric power comprising a rotor, a shield, and a fin mounted on a vertical, central shaft, the fin and shield adjustably interconnected via a cog and gear track arrangement affording variable relative alignment of the fin and shield to position the shield relative to the wind. A constant rotor rotation rate is achieved by varying the masking thereof by the shield to compensate for wind speed variations. A hydraulic rotation rate control system senses the rotation rate of the rotor and generates a signal permitting the adjustment of the relative orientation of the fin and the shield. The rotor is coupled to a conventional electric generator for the generation of electric power.
Abstract: The present invention relates to a fluid motor of the turbine class in which a pair of rotatable blades are carried in orbital revolution around the output shaft of the motor and wherein the blades are operably interconnected to the output shaft and to a weathercock vane so as to present an optimum surface to the driving fluid at all times.
Abstract: Apparatus for deriving a rotational motion from air currents including first and second coaxial annular members spaced from each other along their axes by axial struts and a plurality of blade assemblies carried by the struts. In a preferred embodiment, the annular members are formed of circular I beams and the apparatus is supported for rotation about the axes of the annular members by rollers engaging the web of the I beams. The rollers may be carried by first and second posts with one of the posts being rotatable about the other such that the apparatus can accommodate changing wind directions. The blade assemblies may include an impeller hingedly secured to a cross-beam extending between adjacent struts with each impeller being individually spring biased to present more or less surface to the air current, dependent on its velocity.
Abstract: A plurality of blades are rotatably affixed to a rotatably mounted shaft and overlap each other in a plane perpendicular to the axis of the shaft in a strong wind force. In a weak wind force, the blades rotate to large angles with the axis of the shaft.
Abstract: There is disclosed in the present application a windmill including a wheel having a set of fixed blades and a set of movable vanes whose angular orientation with respect to the axis of the wheel is adjusted automatically for limiting the speed of the wheel to a safe level in winds of high velocity. The fixed blades may be installed to cause turning of the wheel under generally prevailing winds of a very low velocity. The movable vanes are connected to a speed sensing governor mechanism which changes their orientation from positive through neutral to negative for reducing the speed of the wheel when the wind velocity is excessive and the mill would otherwise reach damaging speeds. In addition, there is disclosed a mechanism for changing the orientation of the vanes from a remote location to stop the wheel. The mill wheel is also constructed in modular segments adapted to being shipped in sections and assembled at the operating site.
Abstract: This invention is an overspeed control arrangement for vertical axis wind turbines employing normally vertically positioned rotor blades, said control arrangement allows the rotor blades to tilt either forward or backwards to form a swept wing configuration, at wind turbine speeds beyond the design rpm. When the rotor blade is in a highly swept wing configuration its high drag and low lift reduces the turbine rotor torque to zero and eliminates excessive overspeeding and structural damage. The rotor blade can tilt about a radial or nearly so, tilt-support arm, mounted on a concentric bearing, the tilting starts at the feathering design rpm which is controlled by the geometric position of the combined center of gravity of both rotor blade and tilt-support arm. The control arrangement is automatic and passive and does not require the use of springs, pulleys or levers.
Abstract: A vertical axle paddle motor including a support structure with a rotor mounted on the vertical axle, the rotor having a plurality of arms with paddle members pivotally attached to the end of the same. Each of the paddle members include a plurality of adjustable vanes which move from an open to a closed position within the paddle. Vane position in the paddles is controlled by a wind velocity and wind direction control, operating a pair of cams forming a composite cam surface which is engaged by cam followers on each of the rotor arms associated separately with motors on the paddle, to adjust the position of the vanes within the paddles for maximum efficiency in rotation. The wind velocity cam may be adjusted relative to the wind direction cam to increase the amount of time the vanes of the paddles are held in an open position to reduce and stabilize rotation of the rotor.
Abstract: A vertical axis wind turbine comprises one or more aerofoil section blades attached to a support structure. The blade has at least one part thereof which is acted on by centrifugal forces as the blade rotates with the support structure and thereby caused to increase its angle of inclination to the said vertical axis when the speed of rotation increases beyond the normal operating range, whereby the rate of increase of rotational speed with wind speed is reduced.
July 19, 1976
Date of Patent:
May 2, 1978
National Research Development Corporation
Abstract: A blade mounting having journal and thrust bearings locating the blades in a hub to relieve load and therefore friction by a torsionally flexible tension member secured within each blade so that centrifugal forces of the blade are transmitted directly to the hub, instead of thru the thrust bearing. Also, each blade is located in the hub so that the aerodynamic torque and thrust on the blade are transmitted directly to the hub as components of the centrifugal force.
Abstract: A wind machine comprising a fixed or controlled pitch blade assembly to drive a variable displacement or variable clearance fluid compressor. Means which may be mechanical, hydraulic, pneumatic or electrical interconnect the blade assembly and the compressor to vary the fluid displacement or clearance volume of the compressor as a function of the drag or lift forces of the wind on the blade assembly.
Abstract: A wind driven prime mover which is driven by a plurality of arcuately shaped wind vanes pivotally mounted on a rotatable turntable. The wind vanes are pivotally mounted on the turntable with their pivot axle disposed in a vertical plane. The pivots are positioned adjacent the periphery of the turntable, with the pivots being spaced equi-distant from each other and equi-distant from the axis of rotation of the turntable. The bottoms of the vanes are arcuately shaped, with the length of the arc being slightly longer than the space between the pivots so that there is an overlap between adjacent vanes. The convex surface of the vanes face outwardly to provide a concave inner surface.
Abstract: A windmill blade that has a rigid leading edge, a rigid root portion and a movable blade tip. Control of the geometric twist of the windmill blade is accomplished through proper selection of the axis of rotation for the movable blade tip and by controlling the position of the windmill blade tip with a servo motor or by controlling the position of the windmill blade tip with a spring and a weight. The ability to vary the geometric twist of the blade enables the frequency of rotation of the blade to be controlled to reduce wind drags upon the blade. This improved windmill blade eliminates the need for current complicated and expensive rotor hubs which are used to vary the blade pitch angle at the root end of the blade to reduce wind drag upon the blade. Processes related to the windmill blade are also presented.