US Patent 9752556 Multi-rotor vertical axis wind turbine

The multi-rotor vertical axis wind turbine includes a plurality of vertical wind rotors rotatably mounted on support arms extending from the vertices of upper and lower polygonal frame members. The upper end of each rotor is journaled into a plain bearing, and a lower portion is journaled into a freewheeling clutch bearing. A pulley wheel is mounted on the lower end of each rotor. A generator is centrally located beneath the lower frame member and has a rotatable armature shaft extending vertically upward. The pulley wheel of each vertical rotor is connected to the armature shaft by its own separate endless belt.