Abstract: A self-starting windmill of the vertical axis type. Upstanding helical in configuration, pivotally mounted outer blade members surround a central, rotatably mounted shaft are connected to the shaft by radially disposed strut members. Arcuate in planform, pivotally mounted inner blade members are mounted radially inwardly of the outer blade members in a collective triangular configuration and have their respective convex surfaces facing toward the shaft. A weight member and a spring member bias a preselected edge of each outer blade member against wind force.
Abstract: Complexity, and thus reliability difficulties, are avoided in a ram air turbine including a stationary shaft 14 defining an axis of rotation 16. A hub 24 is journalled on the shaft 14 and in turn movably mounts at least one blade 38 for positioning between a feathered position and a plurality of positions of different pitch. A selectively operable brake 96, 100, 116 is mounted on the shaft 14 and a screw 112 is journalled on the shaft for rotation about the axis 16. The screw has a head 114 engageable by the brake 96, 100, 116 and exterior, widely spaced threads 120. A governor plate 50 is disposed about the shaft 14 and includes a sleeve 124 with widely spaced internal threads 126 surrounding the screw 112. The governor plate is connected to the blades 38 to position the same in response to movement of the governor plate 50. A torsional spring 130 is connected to the screw 112 to effect rotation of the same when the brake 90, 100, 116 is disengaged.
Abstract: Wind turbines, improved gear box assemblies, sub-assemblies and components therefor, and a braking system adaptable for use with such wind turbines and improved gear box assembly.
Abstract: Wind turbines, improved gear box assemblies, sub-assemblies and components therefor, and a braking system adaptable for use with such wind turbines and improved gear box assembly.
Abstract: A windmill construction embodying an improved arrangement for driving a load through a centrifugal clutch and for adjusting the pitch angle of the blades. The adjusting mechanism is responsive to speed so as to increase the pitch angle as the speed increases and further incorporates a latch mechanism for latching the blades in a maximum feathering pitch angle and for introducing a hysteresis effect into the mechanism.
Abstract: An improved gear box assembly is provided for a vertical axis wind turbine, the vertical axis wind turbine having a rotor having a centrally disposed axis oriented in the vertical direction, a bull gear supporting the rotor, a base below the bull gear, the bull gear being adapted to rotate above the base, the bull gear and base presenting a hollow housing and shaft terminating in an inner end wall and end surface respectively, the housing for receiving the shaft, one of the said hollow housing or shaft being stationary and the other being rotatable with respect thereto and secured to the bull gear, the shaft and housing when secured together presenting a space between the inner end wall and end surface, bearings supported between the housing and shaft, and sealing means for sealing the space between the housing and shaft, a fluid passageway extending into the space created between the inner end wall and end surface for feeding hydraulic fluid under pressure into the space for hydraulically elevating the bull
Abstract: The invention provides a wind turbine rotatable about a vertical axis comprising a plurality of planar vanes each situated along the height of a vertical shaft at a separate level. Adjacent vanes are staggered at the same dihedral angle to one another. Each vane has a plurality of doors which pivot between an open and closed position. Auxiliary panels are provided above and below each set of doors to channel the flow of air along the vane thus increasing the power derivable from the wind. Automatic release means for the doors may be provided to prevent structural damage under high wind conditions.
Abstract: A wind machine turns a shaft to activate a multistage pump having intake and discharge means respectively coupled to intake and discharge fluid lines. Control means regulates the operative positions of the intake means or discharge means to remove selected stages from effective pumping while at the same time fluid passes into and from the selected stages. The stages can be of different capacities and selected groups or all of them may be periodically sequentially idled. Torque on the shaft is thereby adjusted to retain the shaft speed in a range for effective wind energy conversion. During starting the stages are idled until an operational speed is reached. Power assisted starting can be achieved by initially reversing the fluid flow through selected stages. Constricting means is located in the common discharge line from all stages and can be additionally located in each discharge line from each stage.
Abstract: A wind machine turns a shaft to activate a multistage pump having intake and discharge means respectively coupled to intake and discharge fluid lines. Idling means is provided for each stage and constricting means is located in series with each stage between the intake and the discharge lines. Control means regulates the idling means and constricting means to remove selected stages from effective pumping while at the same time fluid passes into or from the selected stage. Pressure in the fluid discharge line is retained substantially constant without the need for energy accumulation and at the same time the torque on the shaft can be adjusted to retain the shaft speed in a range for effective wind energy conversion. During starting the constricting means is closed while the idling means opens until an operational speed is reached. Power assisted starting is achieved by initially reversing the fluid flow through selected stages.
Abstract: A windmill including a hub, at least a pair of rotor roots rotatably coupled to the hub and rotor blades mounted on respective rotor roots, wherein wind forces produce rotation of the blades, the roots and the hub around an axis of rotation passing through the hub and the hub defines a plane of rotation perpendicular to the axis of rotation. Each rotor root is mounted in an initial position at a predetermined compound angle with respect to the axis of rotation and the plane of rotation. The rotor roots are spring biased in an initial position and are coupled to each other and to the hub by means of a spring and linkage members disposed in the hub. Upon rotation of the rotors, centrifugal force acts on the rotors in opposition to the spring biasing and produces synchronous rotation of the blade roots relative to the axis of rotation and the plane of rotation thereby decreasing the pitch of the blades with respect to the wind direction and correspondingly controlling the speed of rotation of the rotors.
Abstract: A vertical axis windmill has a blade pivotally connected to a rotatable support structure on an axis passing through its center of gravity which is arranged to lie forward of its aerodynamic center whereby the blade automatically swings outwardly and inwardly when moving on the windward and leeward sides respectively of the axis of rotation of said support means.
Abstract: The horizontal axis wind turbine converts wind into electrical energy and includes a pitch control vane with a flyweight mechanism on each rotor blade to provide aerodynamic efficiency at operating wind velocities, near constant speed and zero lift pitch of the rotor blades when speeds exceed the design speed of the system. A gravity neutralization means composed of a bevel gear and pinions couples the blades together while a flyweight arrangement connected to the bevel gear acts to neutralize centrifugal torque on the blades.
Abstract: A windmill speed limiting device is provided to prevent the windmill blades from going too fast during conditions of heavy winds. In order to slow down the windmill blades, the tips of the blades are turned relative to the main blade portion at high speeds. After the tips are turned, the windmill blade must return to a safe speed before the tips are returned to their normal position. A hysteresis effect by which the tip portions are rotated to their normal angular position in alignment with the main blade portion is implemented by means of a cam track, a pivot point below the center of the blade and a central spring loaded drum to which each of the blades are connected.
Abstract: An improved rotational speed governor characterized by a non-linear response to speed changes, includes a control arm, the angular position of which changes in response to the rotational speed of the governor, the control arm carrying a weight held to a fixed position with respect to the control arm at speeds less than a first predetermined speed and displaced from said control arm by centrifugal force at speeds greater than that predetermined speed to effect a non-linear pivotal displacement response to the control arm.
Abstract: The present invention relates to wind turbines and more particularly to such a device having a horizontally disposed power output shaft pivotally supported by a turntable. Attached to the output shaft are a number of circumferentially spaced apart blades which are each hinged along their leading edges with the hinge axes inclined obliquely to the longitudinal axis of the shaft. A spring controlled governor is provided to control the pivotal position of each of the blades around their respective hinge axis of rotation.
Abstract: Wind turbines are largely divided into vertical axis wind turbines and propeller (horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with rotational speed control systems. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotating shaft by keeping the blade span-wise direction in parallel with the shaft and being provided with aerodynamic control elements operating manually or automatically to control the rotational speed of the turbine.
Abstract: Wind turbines are largely divided into vertical axis wind turbines and propeller (horizontal axis) wind turbines. The present invention discloses a vertical axis high speed wind turbine provided with a starting and braking control system. This vertical axis wind turbine is formed by having blades of a proper airfoil fitted to respective supporting arms provided radially from a vertical rotary axis by keeping the blade span-wise direction in parallel with said axis and being provided with a low speed control windmill in which the radial position of each operating piece varies with a centrifugal force produced by the rotation of said vertical rotary axis.
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.
Type:
Grant
Filed:
July 19, 1976
Date of Patent:
May 2, 1978
Assignee:
National Research Development Corporation