A cycloidal rotor is provided having a flexible by actuators or self-flexing blade-positioning tack, which can be brought into shape corresponding to currently desired blade orbit. This rotor can also be provided with frontal shielding or partial enclosure to assure that rotor operates at any speed as if in hovering flight; rotor track can be inclined to produce forward thrust or external thrusters can be used. Optionally in other embodiments blade orbit shape is determined by a variable cam mechanism or the inclination of blade positioning track of fixed shape to produce a change of its projected shape onto blades' plane of operation thus changing blades elliptic orbit. Blade centrifugal force countervailing mechanism is also proposed.

A vertical turbine comprising a blade control mechanism including a sun gear engaging a plurality of planetary gears each coupled to blade assemblies. The sun gear has at least half circumference of its teeth removed, as the turbine receives maximum downstream torque in the circumference with teeth and it leaves blades free to rotate in the circumference without teeth for minimum upstream drag. The turbine converts the rotational blades into parallel movement and unidirectional propulsion with minimum turbulence.

This disclosure provides a vertical-axis windmill including a rotating vertical shaft and at least one vane assembly mounted to the rotating vertical shaft. The vertical-axis windmill rotates around a vertical axis when wind impinges upon the vane assembly. During rotation, a planar sail of the vane assembly moves along an oscillatory arc of about 90°, with the planar sail assuming each of a vertical orientation and a horizontal orientation once during each 360° rotation of the vertical shaft. As described below, this configuration advantageously allows the windmill to be self-starting and suited for operation at low wind-speed.

A rotor for power driving includes a hub, a plurality of first fixed jibs, a plurality of second fixed jibs, and a plurality of outer vanes. The hub is adapted to be coupled with a shaft to rotate together in a single rotational direction. The first fixed jibs are arranged around the hub circumferentially. Each second fixed jib is engaged on an end of a corresponding first fixed jib. Each outer vane is elastically fixed at a corresponding second fixed jib and extends in a direction different from the single rotation direction when not acted upon by external forces such that the plurality of outer vanes, when acted upon by external forces, are elastically movable relative to corresponding second fixed jibs to drive the shaft to rotate along the single rotational direction and can rebound after removal of the external forces.

A fluid turbine apparatus includes a fixed structure and a rotating structure supported by the fixed structure. The rotating structure includes a central shaft, and at least two wings connected to the central shaft. Each of the wings includes a wing frame, at least one door and a respective at least one door stopper. Each of the doors pivots relative to the respective wing frame between closed and open positions. In use, the door located at one side of the central shaft facing a flow of fluid is in the closed position with fluid force transferred to the door, while the door located at the opposite side of the shaft is in the open position with fluid passing through the respective wing frame. The fluid force creates a torque that rotates the central shaft. Apparatuses can extract power from wind or water current.

Methods and apparatuses for wind turbine vane pitch control including a turbine shaft that transmits mechanical power, a vane support structure that is coupled to the turbine shaft, a vane that is coupled to the vane support structure through a vane shaft, a balancing weight that is coupled to a first location of the vane, and an alignment weight that is coupled to a second location of the vane.

A vertical axis wind turbine rotor with a base having a rotational centre, a top surface, a top surface edge, and a plurality of top plates disposed radially around the rotational centre. The rotational centre defines an axis of rotation substantially orthogonal to the top surface. The top surface extends radially from the rotational centre to the top surface edge. Each of the top plates has a leading edge coupled to the base. Each top plate is passively transitionable between a first position above at a first height, and a second position above the top surface at second height. The rotor may also have a bottom surface with a plurality of bottom plates coupled thereto and disposed radially around the rotational centre. The bottom plates can be passively transitionable between a raised position and lowered position.

Disclosed is a vertical axis wind turbine air concentration tower with reduced radar cross section. The air concentration tower has a polygonal outer perimeter, a pivot located at each vertex of the polygonal outer perimeter, and an inwardly-positioned rudder blade operatively connected at each pivot. Each inwardly positioned rudder blade has a first wind-neutral position, and is pivotable through a plurality of angles that adjust based on an incoming wind direction, such that the incoming wind is channeled to the vertical axis wind turbine, which is located approximately at a center area of the polygonal outer perimeter. A radar absorbent material is applied to the vertical axis wind turbine air concentration tower to reduce the radar cross section. The air concentration tower is designed to provide higher wind speed to the vertical axis wind turbine than the surrounding ambient air.

The invention is made up of a supporting tower on which a rotor is installed, which comprises two parallel crossarms having two parallel rings fastened to the outer ends thereof which serve as a support for the bearings which, secured to the outer casing, make up the rotor, and said casing fixed on the inside thereof comprises a toothed wheel for transmitting the force of rotation, by epicyclic gearing, to the interior of the tower which forms a space suitable for housing the transmission, which is necessarily vertical, and runs towards the multiplier box. The blades are formed on two horizontal parallel beams which are joined and compacted together by metal boxes which house the guiding mechanisms and shafts that support and orient the blades.

A rotary converter of wind energy with a vertical axis of rotation includes a rotor with a vertical axis of rotation 4, which has two or more shovels 6 connected to a central body 5 and/or to each other. The shovels called “working” shovels have wind-permeable structure 2. On one side of the shovels is formed a working surface. It is formed on same side of all working shovels by a flag or flags 1 of which the structure limits the capability to take the direction of the air flow, meeting with this side of the shovels. By this surface, the shovels catch the wind energy and convert it to a rotational motion of the rotor. The shovel's load and the rotor speed can be regulated.