Report KD 654 can be copied for free from my website:
www.kdwindturbines.nl at the menu KD-reports. The title of KD 654 is: "Calculations executed for the 3-bladed rotor of the VIRYA-3.6PC windmill (lambda design = 4.5, galvanised steel blades) driving the VIRYA-4.2 PM-generator for 26 V star or driving a centrifugal pump through a rectangular gear box and a vertical shaft in the tower. Description of the pitch control safety system".
In KD 654, a 3-bladed steel rotor with a diameter of 3.6 m is described. The rotor is provided with a rather simple pitch control safety system to limit the rotational speed and thrust for wind speeds above 8 m/s. The system is only steered by the aerodynamic moment and every blade has its own torsion spring. A drawing of the whole rotor is given in figure 1 of KD 654. A drawing of the pitch control mechanism is given in figure 6 of KD 654. This drawing is added as attachment. I have no intention to build and test this rotor but the idea might be useful for others.
