Windmill with variable pitch blades - pitch of blade is automatically reduced as wind force increases

摘要

A windmill has blades (1, 2) mounted in bearings in triangular frames (7) (8), so that they can rotate about a radial axis. The inner ends of the frame (7, 8) are mounted in bearings (10) at the ends of a T-shaped member which can slide axially against a spring in the rotor shaft (12). Each blade has an arm provided with a ball joint (23, 25) which connects it to the collar (26) which is keyed to the shaft (12). When the rotor speed increases with increasing wind force the angle (B) of inclination of the blade axes decreases due to centrifugal force and the bearings (10) move outwards against the spring, causing the blade pitch to reduce since the rods (30, 31) exert a force on the blade arms.