Horizontal axis wind turbine

Abstract

A horizontal axis wind turbine is disclosed. When a wind direction changes to blow against a rotor from a rear side, a pitch angle of a rotor blade of the rotor are controlled to reverse a rotation of the rotor, without turning of the rotor to the rear side.

1 . A horizontal axis wind turbine, wherein when a wind direction changes to blow against a rotor from a rear side, a pitch angle of a rotor blade of the rotor are controlled to reverse a rotation of the rotor, without turning of the rotor to the rear side.  
     
     
         2 . The horizontal axis wind turbine according to  claim 1 , comprising: 
 a nacelle to support the rotor;    a tower head which the nacelle is mounted on and comprises a rail with a circular or arc shape thereon; and    a roller to support the nacelle, which is movable on and guided by the rail, to control an azimuth direction of the wind turbine.    
     
     
         3 . The horizontal axis wind turbine according to  claim 2 , further comprising an extendable and retractable actuator through which the rail is supported on the tower head, to control an inclination angle of the wind turbine so as to coincide with an upflow or downflow angle of a wind.  
     
     
         4 . The horizontal axis wind turbine comprising: 
 a rotor having a rotor blade;    a nacelle to support a rotary shaft of the rotor;    a tower head which the nacelle is mounted on and comprises a rail with a circular shape thereon supported by an extendable and retractable actuator; and    a roller rotatably attached to the nacelle through a shaft,    wherein the roller is movable to rotate on and guided by the rail, to make an azimuth direction of the wind turbine coincide with the azimuth direction of a wind, and the actuator is extendable and retractable to make an inclination angle of the wind turbine coincide with an upflow or downflow angle of the wind.    
     
     
         5 . The horizontal axis wind turbine according to  claim 1 , wherein the horizontal axis wind turbine is a downwind type.  
     
     
         6 . The horizontal axis wind turbine according to  claim 1 , wherein the rotor comprises a plurality of rotor blades, and a pitch angle of each of the rotor blades is independently changeable to each other.  
     
     
         7 . The horizontal axis wind turbine according to  claim 6 , wherein the pitch angle of a rotor blade is changed by rotating the rotor blade about a pitch axis thereof.  
     
     
         8 . The horizontal axis wind turbine according to  claim 7 , wherein rotation of the rotor blade about the pitch axis is performed by rotating a base end of the rotor blade by a motor provided in a hub, through a gear.  
     
     
         9 . The horizontal axis wind turbine according to  claim 3 , wherein the actuator is a hydraulic jack.