Rotor	Main shaft
Gearbox	Yaw bearing
Generator	Radiator
Yaw motor	Controller
Anemometer	Wind Vane
Mechanical brake	Small Shaft

	Gearbox The rotor turns with app. 22 revolutions per minute (RPM). But the generator has to turn 1500 revolutions per minute. The gearbox converts the 22 revolutions to 1500 revolutions.

	Yaw bearing The large cam wheel is mounted onto the tower. The cam wheel of the yaw motor engages the large cam wheel and turns the nacelle with the rotor into the wind.

	Rotor The rotor is bolted onto the big main shaft. The large rotor has three blades, which catch the wind. The wind will turn the rotor if there is enough power in the wind.

Small shaft The small shaft leads the power from the gearbox to the generator. The small shaft runs very quickly, approx. 1500 revolutions per minute.

	Anemometer The anemometer measures the wind speed. It sends information about the wind speed to the controller all the time.

	Wind Vane The wind makes the wind vane turn. The wind vane tells the controller where the wind comes from. The controller then tells the yaw motor to yaw – that means turn – the rotor up against the wind.

	Controller The wind turbine controller is a computer that controls the many parts of wind turbine. The controller yaws the nacelle against the wind and allows the wind turbine rotor to start when the anemometer tells it that there is enough wind.

	Mechanical Brake The mechanical brake is used when the wind turbine has to be repaired or it has to be serviced. It ensures that the rotor will not start turning.

	Generator The generator makes electricity when it turns. The current is sent down through the tower in large electricity cables.

Radiator
When the generator is running it gets very hot. But if it becomes too hot it will break down. This is why it has to be cooled down.
In some wind turbines (such as this one) the generator is cooled by water. The radiator cools the water.

	Yaw motor The yaw motor turns the nacelle so that the rotor faces the wind. The motor has a cam wheel which fits into the large yaw bearing cam wheel. The controller tells the yaw motor when to turn the nacelle.

	Main Shaft The rotor turns the large shaft. The shaft is connected to the gearbox. The rotor uses a large force to turn the shaft. Therefore the shaft has to be very thick.