Hydraulic pitch control for wind-turbine blades

deublin pitchcontrol1

Hydraulic pitch control for wind turbine blades is possible with rotary unions from Deubline Inc.

Generating steady shaft speed on a wind turbine means constantly adjusting the pitch of each blade to accommodate wind variations. The blades connect to a huge hub mounted to a shaft that turns a gearbox and a generator. Best turbine efficiency calls for a continuous pitch control on the blades.

Blade pitch is powered by either an electric or hydraulic drive. Electric-pitch control uses slip rings to conduct power to motors rotating in the hub. Hydraulic systems, on the other hand, use a rotary union to deliver hydraulic power to the drive motor. The industry is split about 45% electric and 55% for hydraulic controls. The advantage of the hydraulic control is that its power density is higher than electrical equipment and it needs fewer components, making for a simpler system. There are other pluses.

Rotating unions, such as those from Deublin Co., are precision mechanical devices for transferring fluid from stationary sources to rotating machinery. Ball bearings in a typical union support the rotating components (attached to the machinery) against the stationary component (attached to the fluid supply) and a mechanic seal prevents leaks. While often found on wind turbines, rotating unions device work well in other applications such as air clutches, gearboxes, machine tool spindles, and more.


  1. slip ring is not a high-tech product like electric chips, it only worked as a connection and transmission. It may not important like a heart, but it connected all the hardware, software and make them freely contacted.
    more information:http://www.moflon.com

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