Hydraulic systems & components


High pressure rotating unions for wind turbines

1st Quarter 2013 Hydraulic systems & components

Wind turbines make huge demands on their components. Generating steady shaft speed on a wind turbine requires constant adjustment of the pitch of each blade to handle wind variations. The blades connect to a huge hub mounted to a shaft that turns a gearbox and a generator. To achieve optimum turbine efficiency, continuous pitch control on the blades is critical. Blade pitch is powered by either an electric or hydraulic drive. Electrical pitch control uses slip rings to conduct power to large powerful motors rotating in the hub, which require reliable battery backup. Hydraulic systems, on the other hand, use a rotary union to deliver hydraulic power to the drive motor. The advantage of hydraulic control is that its power density is higher than electrical equipment and it needs fewer components, making for a simpler system and lower wear on moving components.

The most important part of the hydraulic unit is the high pressure rotating union which allows the hydraulic liquid to be pumped from the stationary pressure accumulator into the rotating hub to reach the adjustment cylinders. The requirements for this small component are extremely high: it must safely seal the static part from the rotating part; it must guide the hydraulic medium in a safe manner; it must be installed easily; it must be made of materials which can resist adverse environmental conditions, and it must have a long service life, even with contamination of the medium.

Rotating unions from Deublin, the market-leader in this field, meet these requirements. They are based on a hydrostatic sealing principle with controlled bypass flow to ensure that the sealing faces are lubricated on a permanent basis, a feature contributing to durability. They are available in single- to multi-channel designs and, depending on the model, generate up to 250 bar hydraulic pressure, as well as having a central channel for sensor technology or connection to a slip ring. Furthermore, hydraulic systems equipped with a Deublin rotating union are secured against oil leakage, so there are no environmental implications.

For more information contact Mike Vernes, Pneumatic Electric Control Systems (PECS), +27 (0)31 303 3701, [email protected], www.pecspower.co.za





Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Hydraulic pumps deliver high flow, convenience and precision
Bearing Man Group T/A BMG Hydraulic systems & components
BMG’s range of high-performance hydraulic electric Enerpac E-pulse pumps is critical to all 700 bar operating hydraulic systems. These portable E-pulse pumps have intelligent auto-cycle functionality and an efficient power-to-weight ratio to ensure dependable operation and high productivity in challenging industrial applications.

Read more...
Precision, control and performance in regulators and control valves
Valve & Automation Hydraulic systems & components
Cashco has long been a trusted name in industrial control solutions, offering a broad range of regulators and control valves designed to meet the rigorous demands of various industries.There are two key Cashco product lines, its regulators and the Ranger QCT control valve.

Read more...
New-generation drill rig
Hydraulic systems & components
Epiroc is launching the new-generation PowerROC T35, offering both increased fuel efficiency and faster operations.

Read more...
Electrohydraulic shredding
Hydraulic systems & components
Galvanised parts are among the last big challenges for recycling. ImpulsTec is implementing shockwave or electrohydraulic shredding technology, for the separation of complex material compounds in industrial processes.

Read more...
Revealing the value of filtration
Hydrasales Hydraulic systems & components
The life and reliability of hydraulic systems are greatly affected by the presence of particulate contamination in the lubricant. However, in the face of potential contamination there is hope. The cleaner the fluid, the more reliable the system or process, and the longer the lifespan of its components.

Read more...
Flat face and flat face screw couplings for mining
Hydraulic systems & components
Quick couplings are the critical connectors that keep mining systems running. Within the mining industry, the choice of coupling can significantly impact equipment performance, downtime, and maintenance costs. Stucchi offers flat face and flat face screw couplings that are designed to withstand mining’s unique challenges.

Read more...
Hytec Engineering and Power Team collaborate on water tank project
Hydraulic systems & components
Hytec Engineering and Power Team have collaborated on an innovative water tank project featuring advanced engineering and a specialised synchronised mobile lifting system.

Read more...
Decades of excellence in mobile and industrial hydraulic solutions
Axiom Hydraulics Hydraulic systems & components
For over four decades, Impro Fluidtek has been at the forefront of hydraulic solutions in mobile and industrial applications. This is borne out by four patents and the sale of over three million hydraulic orbital motors across three continents.

Read more...
Acoustic imaging detector for gas leaks and partial discharge
Artic Driers International Hydraulic systems & components
The new SUTO iTEC S532 acoustic imaging detector provides an easy and effective way to locate pressurised air and gas leaks and partial discharge (PD) in industrial high-voltage environments.

Read more...
Bending the law of size, power and speed
Hagglunds Drives SA Hydraulic systems & components
The Hägglunds Quantum hydraulic motor range exceeds previous performance limits in torque, speed and efficiency. Hägglunds Quantum is the new name for the Hägglunds CB range, and these direct drives can be used in heavy-duty and mobile applications.

Read more...