Abstract: An horizontal axis wind turbine having a rotor (3) with a frontal projection comprising a stationary spherical head (1) upstream of its multibladed turbine rotor (3) displaces and increases the speed of wind addressed over 70% of the total frontal area. A series of thin airfoils (12) radially and evenly placed on said spherical head (1) to direct wind towards the turbine short blades (4).

Abstract: A small, easily transportable wind turbine system has a square rail base secured to the ground by stakes and by its own weight. Slanted vertical legs connect a smaller square upper support perimeter to the base. A three-section telescoping mast is attached to the base and to the upper support. Winches and guy wires raise the second mast. As the second mast is raised, static guy wires raise the third mast. A wind generating turbine is attached to the top of the third mast. A controller senses the maximum output of the turbine and raises or lowers the height of the masts such that the minimum wind speed necessary to produce the maximum electric output is produced. The controller also feeds energy to a battery storage system and directly to a utility panel.

Abstract: Systems for protecting a wind turbine in high wind conditions are disclosed. A shrouded turbine may have an ejector shroud disposed adjacent and downstream of a turbine shroud. In one version, the ejector shroud can move to surround the turbine shroud. In another version, the turbine can be pivoted on a support tower to cover the intake end of the turbine and rotate the turbine about an axis at a right angle to the tower axis. In another version, the turbine is supported by a telescoping tower which may be retracted to lower the turbine in high winds. In another version, the tower sections may be connected by a pivotable connection and supported by guy wire(s) which may be lengthened to lower the upper tower section pivotally.

Abstract: A device is described for the conversion of energy from free flowing water into electric, hydraulic, or pneumatic power using a submersible system of turbine propellers mounted on horizontal shafts supported by chambers, each containing switchgear and/or generators and air or water ballast. The device is tethered to the seabed by a cable. Free of a rigid vertical support, the device can yaw so that water flow in any direction can be used for power generation, as in a tidal basin. In response to sensing the water velocity of the water channel, the device actively seeks a nominal water velocity, ascending or descending as necessary.

Abstract: Installations for harvesting energy of river and ocean tidal currents consist of multiple Darrieus type turbines with funnels, which are located inline on the river or ocean bottom and oriented perpendicular to direction of water movement due to tide or river current. Use of Darrieus type turbines with funnels significantly increases efficiency of energy utilization of water streams in comparison versus system not utilizing funnels. Use of greater number of Darrieus turbines operating in line allows to utilize more powerful gearbox and generator, thus improving economics of their operation. For the purpose of simplification the regular maintenance of the system the generator and all auxiliary systems are located above water, except 90-degrees gearbox. To prevent water entering 90-degrees gearbox it always is under air pressure slightly above hydrostatic pressure of water above it.

Abstract: A Mixer/Ejector Wind Turbine (“MEWT”) system is disclosed which routinely exceeds the efficiencies of prior wind turbines. Unique ejector concepts are used to fluid-dynamically improve many operational characteristics of conventional wind turbines for potential power generation improvements of 50% and above. Applicants' preferred MEWT embodiment comprises: an aerodynamically contoured turbine shroud with an inlet; a ring of stator vanes; a ring of rotating blades (i.e., an impeller) in line with the stator vanes; and a mixer/ejector pump to increase the flow volume through the turbine while rapidly mixing the low energy turbine exit flow with high energy bypass wind flow. The MEWT can produce three or more time the power of its un-shrouded counterparts for the same frontal area, and can increase the productivity of wind farms by a factor of two or more. The same MEWT is safer and quieter providing improved wind turbine options for populated areas.

Abstract: The flow of fluid into energy capture machines is crucial for determining the amount of energy extracted, particularly in the field of renewable energy resources. The current invention describes devices and methods for applying the physics of flow to energy capture machines, most commonly wind and water turbines, by enhancing the flow into the energy capture component by the appropriate placement of various objects called flow deflection devices (FDD). FDDs can make a highs significant improvement in power output.

Abstract: A rotatable impeller is a hollow conical/cylindrical stack, with at least one slanted/vertical side portion and at least one level of stack portions. Each impeller comprises at least one shape of airfoil/hydrofoil for thrust to propel, or pull, i.e., to draw in, vapor or fluid; plus a dynamic application utilizes a reverse operation to generate electricity from the kinetic energy of the flow of vapor or fluid. One airfoil/hydrofoil configuration of a stack impeller comprises serpentine rectangular segments positioned by internal rib members. Considered additional levels are enlarged copies of the first level of the stack impeller, positioned at an engineered distance from each level, are considered to amplify propulsive or vacuum force; or for energy recovery to operate a dynamo generator.

Abstract: An apparatus for generating electricity from fluid currents comprises a continuous loop structure and at least one blade movably mounted relative to the continuous loop structure and extending in a direction radially outward relative to the continuous loop structure, the at least one blade being configured to rotate about an axis of the continuous loop structure. The at least one blade may be configured to interact with fluid currents moving in a direction approximately parallel to the axis of the continuous loop structure to rotate the at least one blade about the axis of the continuous loop structure. At least a portion of the least one blade may intersect a plane of the continuous loop structure that is substantially perpendicular to the axis of the continuous loop structure. Rotation of the at least one blade may generate electrical energy.

Abstract: Embodiments include apparatus and methods of fluid energy conversion. One embodiment relates to a tube for a fluid energy converter. The tube may include a generally cylindrical and hollow body having an interior surface, an exterior surface, and a longitudinal axis. Another embodiment includes a fluid energy converter having a longitudinal axis and a rotatable tube coaxial about the longitudinal axis. In some embodiments, the rotatable tube converts kinetic energy in a fluid into rotating mechanical energy, or converts rotating mechanical energy into kinetic energy in a fluid.

Abstract: A ventilation assembly for a wind turbine rotor hub is provided, the ventilation assembly comprising a frame fixedly mountable to the rotor hub, the frame including at least one opening, and a cover for said at least one opening, the cover being mounted to said frame to be freely rotatable with respect to said frame, wherein the cover has at least one ventilation opening to allow the ingress and egress of air and has a shielding member for shielding the at least one ventilation opening against ingress of liquid running down the rotor hub.

Abstract: An accelerator for a wind power electrical generating system which mounts at least one wind turbine and which defines an air passageway capturing and delivering wind to the turbine. The accelerator comprises a cage-like support structure of thin sturdy members which defines in three-dimensional outline the air passageway. A cover which is mounted on and about the support structure in a floating relationship therewith may be injection-molded or thermo formed plastic. Connecting members between accelerators are provide with labyrinth seals.

Abstract: An airborne system for producing electricity from wind energy includes a shaft, at least two turbines rotatably mounted to the shaft and arranged to rotate independent of one another and in opposite directions when subjected to the same wind, and generators which convert rotation of the turbines into electricity. The magnitude of electricity generation by the generators is related to the magnitude of torque induced by the generators on the shaft, and the electricity generation by the generators may be controlled such that torques induced on the shaft by the generators is controlled such that a sum of torques induced on the shaft is substantially zero. A lifting structure generates a lifting force to lift the turbines to a desires altitude, and an anchoring system anchors the turbines relative to the ground. Generated electricity is conducted to users, to electricity storage, or to processing components.

Abstract: Disclosed is a method and system for providing an energy gathering sheet to harness and provide energy to destinations, such as homes and businesses. The energy gathering sheet is configured to receive small wind energy gathering devices (e.g., in the micrometer to nanometer range), which are mounted on a single sheet for the purpose of creating efficient and clean energy to meet both small and large power demands. The single sheet of installable wind turbines may be loosely rolled or stacked to protect the integrity of the wind turbines, and are capable of being roiled out for efficient installation.

Abstract: A tandem axial turbine comprises a front, confusor funnel-shaped runner having inner blades and capable of accelerating and directing an oncoming flow toward a co-axial rear runner which rotates in an opposite direction. A tangential turbine has a hub, blades capable of rotating in relation to the hub between positions across and along the flow, and a propulsion springs for controlling the movement of the blades in relation to the hub and the transfer of the energy. A second tangential turbine comprises a runner having a hub and blades and a shroud capturing the runner from above and around and permitting the blades to dip into water flowing immediately below the hub and an opening of the shroud. A surface vessel comprises a stabilized frame rotatably affixed on a vessel hull about a center of wave induced rocking motions of the vessel and therefore isolated from a rocking motion of the vessel.

Abstract: A preferred embodiment includes a system for power generation through movement of fluid having a variety of configurations and implementations. One preferred embodiment includes a system for power generation through movement of fluid includes a power generating cell with a generally cylindrical housing a ring for rotating disposed in said housing, one or more impellers fixedly coupled to said ring, and a generator operably coupled to said ring for receiving energy from the one or more impellers in which fluid is disposed about one or more impellers for creating energy.

Abstract: An apparatus and method for a wind power foundation. An embodiment of a wind power plant includes a tower having a top and a bottom. The plant also includes an assembly, the assembly including a transition piece that is coupled with a concrete cap. The assembly has a top and a bottom, with the top of the assembly being coupled with the bottom of the tower. The plant also includes a jacket structure. The jacket structure has a top and a bottom and multiple legs, with the bottom of the assembly being coupled with the top of the jacket structure.

Abstract: A roadway system for energy generation and distribution is presented. In accordance with one embodiment of the invention, the roadway system comprises a plurality of ground-based wind energy generating devices, one or more roads, and a roadway system electricity grid. The roadway system may additionally include, for example, a plurality of ground-based solar energy generating devices, one or more vehicle-based solar energy generating devices and one or more vehicle-based wind energy generating devices. The energy generating devices are connected to the roadway system electricity grid and substantially all of the ground-based wind energy generating devices are positioned on part of one of the roads or near to one or more of the roads to thereby allow energy generation from wind created from passing vehicles in addition to energy generation from atmospheric wind.

Abstract: A method of mounting windmill blades their enhance performance is disclosed. The blades have a transverse cross-sectional shape having a predominately flat chord section and are mounted such that the chord section lies in a plane that is substantially at 90 degrees to the axis of the shaft upon which they are mounted.

Abstract: A multidirectional hydrokinetic power generating turbine has an impeller housing with one or more impellers disposed within the impeller housing, one or more adjustable ducts pivotally connected to the impeller housing, and a plurality of duct leafs disposed about the one or more ducts. The plurality of duct leafs articulate and cause the one or more adjustable ducts to converge and diverge to selectively disposing a fluid about the one or more impellers.

Abstract: A wind-powered turbine has a housing with an inlet and an outlet. Located in the housing is a cylindrical stator array having a plurality of spaced-apart stators located in it. An annular cylindrical rotor array having a plurality of cups rotates about a central axis, fits inside of the stator array. The stators are positioned to cause air which flows around the outer periphery of the stator array to impinge on the rotors and an air handling system causes air entering the housing to be distributed substantially around the periphery of the stator array.

Abstract: Creating a large fleet of vehicles, which gather wind energy and generate wind generated energy, such as electricity, is impeded by the cost to an individual vehicle owner. Accordingly, a system and corresponding method to gather wind energy and deposit stored wind generated energy for system credit is provided. The present invention includes a vehicle-based wind energy gathering device to gather wind energy and generate wind generated energy, a vehicle-based energy storage system, electrically coupled to the wind energy gathering device, to store wind generated energy, and means for depositing the stored wind generated energy for system credit. As such, individual vehicle owners have an incentive to participate in gathering wind energy and depositing wind generated energy, such as electricity. By taking advantage of potentially millions of participants and participating vehicles, the present invention creates a format for generating energy from multiple forms of wind energy on a wide-scale.

Abstract: A wind driven vertical axis power generating system is disclosed. An air scoop directs air from the prevailing wind into an air turbine. An exit drag curtain provides for an efficient re-entrainment of the power generating air back into the prevailing wind. The design provides for an efficient method of utilizing the energy from a prevailing wind. The air scoop and exit drag curtain may be rotated to be suitably oriented to the prevailing wind direction. The invention is visually pleasing in shape, as well as efficient in the production of useful power.

Abstract: Offshore wind turbine (14) including a tower (1) rising above sea level (12) and one or ore blades (4), which can be put into rotation by wind. The offshore wind turbine includes a pump (6), which is adapted to pump sea water (13) up form the sea. At the delivery side the pump (6) communicates with nozzles (8, 9), said nozzles being adapted to direct sea water to the surface of the blades (4).

Abstract: To provide a horizontal axis wind turbine capable of reducing flutter, and by extension, reducing the load on the wind turbine, without controlling the yaw, regardless of the direction of the wind relative to the nacelle. When the wind speed is above a specific value, the yaw angle of the nacelle is held constant, the blade pitch angle is controlled according to the yaw angle Y of the wind direction relative to the nacelle, and the rotor is allowed to rotate freely. Even when the yaw angle of the nacelle is held constant, allowing the rotor to rotate freely makes it possible to reduce the load by avoiding flutter.

Abstract: A horizontal axis wind turbine includes: a rotor having a hub and at least two or more blades; a nacelle for pivotally supporting the rotor through a rotating shaft connected to the hub; a tower for supporting the nacelle; and an independent pitch control unit capable of independently controlling pitch angles of the blades, respectively, wherein the independent pitch control units control the pitch angles so that all the blades are made in a full feather position in case of a wind speed not less than a predetermined value, and subsequently controls the pitch angles of the respective blades so as to be sequentially reversed one by one, and further subsequently, carries out control so that the wind turbine idles in an all-blade negative feather position where the pitch angles of all the blades are reversed.

Abstract: A method in connection with a wind turbine installation for damping tower vibrations, in particular a floating wind turbine installation comprising a floating cell, a tower arranged over the floating cell, a generator mounted on the tower that is rotatable in relation to the wind direction and fitted with a wind turbine, and an anchor line arrangement connected to anchors or foundations on the sea bed. The tower's eigenvibrations, ?eig, are damped by, in addition to control with the controller in the constant power or RPM range of the wind turbine, an increment, ??, being added to the blade angle of the turbine blades on the basis of the tower velocities, ?Z, so that the eigenvibrations are counteracted.

Abstract: A wind turbine comprising: (1) a support portion; (2) a hub that is mounted to rotate adjacent the support portion; and (3) at least one turbine blade mounted adjacent the hub and that comprises both a rotor and a sail that is mounted adjacent the rotor. The rotor may be in the shape of an airfoil, and the sail is preferably mounted to be selectively extended and retracted adjacent the rotor. The wind turbine may include a boom that extends adjacent the rotor. In one embodiment, the sail is mounted so that the sail is stored adjacent within, or adjacent a rear surface of, the boom when the sail is in a retracted position. The exterior surface of the boom may be substantially in the shape of an airfoil. In one embodiment, the wind turbine is configured to selectively extend or retract its sails in response to varying weather conditions.

Abstract: The invention relates to a wind turbine and a method for operating the wind turbine planted in the floor of a body of water. The wind turbine includes a support structure and a rotor, which is arranged on the support structure. The rotor has a rotor blade. The wind turbine operates in a trundle mode in order to reduce the oscillations in the support structure created through mechanical impacts on the support structure.

Abstract: The invention relates to a wind turbine comprising a machine housing (12) equipped with a rotor (14), which is mounted to pivot on a sub-structure (10). Wind parameters and an electromechanical quantity are determined by means of measuring devices (21, 22, 23). To enable the machine housing (12) to track the wind, the wind turbine is equipped with a pivoting device (11) comprising a controller (8). The wind turbine is also equipped with a calibration module (2), which is configured to determine an effective mass of the electromechanical quantity using the wind speed. In addition, the turbine comprises an evaluation device (4) comprising a classifier (40), which is used to form a first average value for a first class, for which the wind direction is positive and a second average value for a second class, for which the wind direction is negative. A difference is determined by means of a comparator and a calibration signal is emitted to the controller (8) of the pivoting device (11).

Abstract: A wind power plant having a tower open at the top and provided with a side inlet for the wind for generating a cyclone in the tower and a substantially horizontal turbine that has inlets through the base and an outlet to the center of the cyclone in the tower and that is driving a generator. The tower is rotatable and has a non-circular elliptical shape viewed in the horizontal plane. This shape increases the power of the wind power plant as compared to a tower with a circular shape. During operation, the tower is turned so that the wind inlet is always facing the wind.

Abstract: A wind power generation device capable of improving power generation efficiency is provided. The wind power generation device according to the present invention comprises: a substantially cylindrical duct 1 having a side wall with a substantially wing section; an impeller 2 rotatable around an axis of the duct 1; and a nacelle 5 that constitutes a streamlined pencil body 3 together with the impeller 2 and houses a generator 4 that uses torque of the impeller 2. The duct 1 has the side wall with the wing section so as to be able to produce a reduced pressure area at a rear of the duct and prevent generation of swirl at the rear of the duct 1. The pencil body 3 is provided so that a tip thereof is placed in the duct 1 and a rear end thereof protrudes from a rear end of the duct 1 so as to be close to a tip of the reduced pressure area produced at the rear of the duct 1. Blades 21 of the impeller 2 are provided in a maximum wind speed area 13 in the duct 1.

Abstract: A device and method for conversion of the energy of medium flows are provided. The proposed device and method ensure suppression of the vortex streams in the flow on the leg of its motion along the radially converging trajectories and concentration of the flow energy, which is expressed by the increase of its velocity and decrease of the summary area of the cross section of the converging trajectories. As the flow runs along the first system of helical trajectories the following takes place: the harmful secondary vortex jets continue attenuating, the degree of concentration of the flow energy increases and velocity components form in the flow, which correspond to natural vortex streams, for instance, tornadoes, whirlpools.

Abstract: The invention concerns a rotor blade, in particular a rotor blade of a wind power installation. The object of the present invention is to provide measures for still further improving the CR-value and also the level of acoustic power of rotor blades of wind power installations. A rotor blade for a wind power installation includes a high pressure side and a low pressure side. A substantially constant, area-covering electrostatic field is provided on the low pressure side.

Abstract: A wind turbine is provided having a lidar wind speed measurement apparatus for achieving wind control. The lidar apparatus is arranged to scan the area in front of the wind turbine so as to generate a measurement of the wind speed across the wind field. The lidar apparatus may be located in the hub of the wind turbine and the look direction inclined away from the rotational axis so that rotation of the hub ensures scanning. Preferably the lidar apparatus has a plurality of look directions so as to increase the scanning rate. This may be achieved by having a number of dedicated lidar systems and/or by using multiplexed lidars. Measurement of the wind field allows improved control of the wind turbine giving efficiency and reduced wear benefits.

Abstract: A hydro electric turbine having a flexible, collapsible front shroud, the upstream open end of the front shroud being controlled by a draw line passing through purse rings, whereby the upstream end can be closed by drawing on the draw line, thereby stopping water flow through the turbine. Decreased drag allows the turbine to rise to the surface. Opening the upstream end so that water flows into the turbine increases drag to lower the turbine into the water and causes rotation of the turbine blades.

Abstract: A wind power generator has a base, a wind driving wheel, a transmission unit and a power storage unit. The wind driving wheel has a spindle at a center of the wind driving wheel. The spindle is positioned to the lateral frame. A plurality of connecting frames are extended from a periphery of the spindle. An outer end of each connecting frame is connected to a flow guide plate. A plurality of blades are installed on the flow guide plate. The transmission unit is adjacent to one lateral side of the wind driving wheel. The transmission unit includes a first transmission wheel, a first transmission belt, a first transmission element, a transmission shaft, a second transmission wheel, a second transmission belt, a second transmission element, and a power generator. The power storage unit is connected to the power generator for storing power.

Abstract: A horizontal axis wind turbine of an upwind type includes: a rotor for rotating around a rotor axis extending in a horizontal direction, the rotor being turned in a horizontal plane according to a wind direction; a nacelle having a symmetrical shape with respect to an imaginary plane including the rotor axis and extending a vertical direction; two anemometers disposed at positions of both side portions of the nacelle, the positions opposing each other across the imaginary plane; and a controller for controlling a yaw angle of the rotor based on wind speeds measured by the two anemometers.

Abstract: A wind turbine includes a tower, a nacelle supported at an upper end of a tower, a rotor having at least one blade and being arranged at the nacelle, and a vibration load reduction system disposed at either the tower or the nacelle. The vibration load reduction system includes a base, at least two columns extending from the base, and a flowable mass located within the base and the at least two columns.

Abstract: A habitat friendly, wind energy system is disclosed for safely extracting usable energy from wind. Included are one or more concentrator wings that convert the dynamic pressure of wind into relatively lower static pressure and thereby induces a vacuum that draws wind into an area defined by the concentrator wings. The airflow regulation minimizes or prevents the stalling of, or the generation of a turbulent flow of wind over or between concentrator wings. Further included are multiple impellors, at least one power converter, a riser supporting these component pieces, all positioned within the area defined by the concentrator wings. Accordingly, one or more flow regulators are positioned to assist in promoting laminar flow across or between the concentrator wings and to reduce the dynamic pressure of wind on the riser to thereby increase efficiency of the system.

Abstract: An electrical power generation assembly comprising a main body having a low density to provide lift and wind driven means on its surface to generate electrical power. The main body has a part-circular, or a part-elliptical, cross section frontal region. The main body has a first distance and a second distance. The ratio of the first distance to the second distance is equal to or more than 0.5 and equal to or less than 5 according to the shape of the frontal region of the main body. The ratio of the diameter of the wind driven means to the first distance is equal to or less than 0.25.

Abstract: A pile based braced caisson structural support device includes a number of legs in is used to support a wind turbine. The wind turbine includes a base, a turbine generator and a blade mechanism. The legs are configured in a teepee type configuration such that the footprint of the base is larger than the footprint of the opposing end. This structural support can be used as a base for an offshore platform in that the support reduces the lateral forces on the support caused by wave action.

Abstract: A wind energy conversion device includes a propeller in which each of the propeller blades includes a proximal (radially inward) non-airfoil mounting section, a medial section and a distal tip section mounted to pivot relative to the medial section about a pitch axis running lengthwise of the blade. At low wind speeds, each tip section and its associated medial section cooperate to provide a single airfoil. When the propeller rpm exceeds a predetermined threshold, each of the tip sections begins to pivot toward a full governing position, which tends to reduce the propeller rpm. To permit wind tracking, the device is mounted to pivot on a vertical axis. The propeller blades are downwind of the vertical axis, and slightly inclined to define a cone diverging in the downwind direction. The electrical power generating components are located upwind of the propeller and centered about the propeller axis, and have a radius less than the length of the proximal blade sections.

Abstract: A system for supplying a fluid to a turbine includes an inlet for allowing the fluid to enter the turbines, a filter to filter the fluid, and a pump apparatus to pressurize the fluid and to mix the pressurized fluid with the un-pressurized fluid at a location in the neighborhood of the inlet.

Abstract: A wind energy turbine includes a tower, a nacelle rotatably supported by the tower, a rotor rotatably supported by the nacelle, and at least one unit to be cooled and arranged in the tower and/or the nacelle. The unit is adapted to be cooled by a cooling medium flowing in a cooling circuit from the unit to at least one heat exchanger. The at least one heat exchanger is located outside of the tower and/or nacelle and configured to be cooled by ambient air.

Abstract: A sky turbine, having impeller blades with a plurality of panels that can telescope inward and outward. The pitch of the panels can be adjusted, and the pitch of each panel on a blade, passing from the innermost panel to the outermost panel, differs from the pitch of the previous panel by a certain adjustable amount. The sky turbine is preferably mounted above a city at a sufficiently high elevation that air current will be generally faster than just above the ground. In the preferred embodiments, a wing with two pods is pivotally mounted on a tower. Each pod has front and rear shafts, from which four blades extend. Servomotors cause the wing to turn so that its center of symmetry is parallel to the direction the sky is moving, cause the pitch of the panels of the blades to change, and cause the panels of the blades to telescope.

Abstract: A method for reducing load and providing yaw alignment in a wind turbine includes measuring displacements or moments resulting from asymmetric loads on the wind turbine. These measured displacements or moments are used to determine a pitch for each rotor blade to reduce or counter asymmetric rotor loading and a favorable yaw orientation to reduce pitch activity. Yaw alignment of the wind turbine is adjusted in accordance with the favorable yaw orientation and the pitch of each rotor blade is adjusted in accordance with the determined pitch to reduce or counter asymmetric rotor loading.

Abstract: A wind power generator has an arcuate converging-diverging flow passage and a support body that is prolate in shape and is located in the flow passage. The support body is rotatably supported and a plurality of rotor blades are mounted on the support body. The support body and the flow passage define a converging-diverging flow area through which wind passes to drive the support body via the rotor blades.

Abstract: A horizontal axis wind turbine includes: a yaw sensor; a rotor rotating around a rotor axis extending in a substantially horizontal direction, the rotor axis rotating in a substantially horizontal plane depending on wind direction; a plate-like member disposed on a rotational central portion of the rotor and extending in a parallel direction to the rotor axis and in a vertical direction; two anemometers disposed at positions which are across the plate-like member; and a controller for yaw control based on a difference or a ratio between wind speeds measured by the two anemometers.

Abstract: The present invention relates to a wind generator. The wind generator comprises a body installed freely rotatably at a tower, blades installed at a leading end of the body, a gearbox for receiving rotational forces from the blades, and a generator connected to the gearbox for generating electricity. The blades are coupled with a blade angle adjustment unit so that the angles of the blades can be adjusted at predetermined angles according to the directions and velocities of winds. The gearbox comprises a planet gear coupled with a rotational shaft of the blades, a ring gear which has teeth formed on a radially inner surface thereof and engages with the planet gears, and a sun gear which engages with the planet gear and is connected with the generator. Teeth are formed on a radially outer surface of the ring gear so that teeth of a stop gear can be engaged therewith.