Abstract: Rotary displacement machines are known for their uses as compressors, expansion engines and the like. Many comprise two or more rotors mounted for simultaneous rotation within a casing, with intermeshing or interengagement of lobes and pits as surface features of the rotors, thereby to handle a working fluid. Disclosed herein are rotary displacement machines with improved structures and rotor configurations.

Abstract: Rotary displacement machines are known for their uses as compressors, expansion engines and the like. Many comprise two or more rotors mounted for simultaneous rotation within a casing, with inter-meshing or interengagement of lobes and pits as surface features of the rotors, thereby to handle a working fluid. Disclosed herein are rotary displacement machines with improved structures and rotor configurations.

Abstract: The invention relates to improvements in and relating to vertical axis wind turbines, particularly those of the "eggbeater" type. It has been found possible, in spite of previous beliefs that it was not so, to provide energy exchange means between the blades and the rotor to thereby smooth out cyclic variations in transmitted torque. The energy exchange means may be, for example, the provision of hinges between the blades and the rotor so that the blade is deflected in operation to transmit torque to the rotor in dependence not only on its fixed geometry but also in dependence on the deflection.

Abstract: An overspeed spoiler for vertical axis wind turbines of the type having straight or curved airfoil blades attached to a vertical shaft formed by a relatively thin flat blade shaped spoiler element hinge mounted on the trailing edge, leading edge, or at a central position of a portion of the airfoil section with the element having two portions one of which is held flush or against a surface by spring means with a surface of the blade towards the turbine rotor axis and the other lies substantially parallel to the chordline of the airfoil, the weight and configuration of the element being such that a predetermined turbine rotor speed the element rotates against the spring force because of centrifugal action and takes up a position generally transverse to the air flow direction such as to cause much increased drag and control overspeeding of the rotor.