Press releases

Ask the Experts – The Lubrication of Wind Turbines

September 18. 2012

Ask the Experts – The Lubrication of Wind Turbines

Speciality lubricants in wind turbines extend maintenance intervals and avoid downtimes

Background information - The still young technology of wind power plants benefits from Klüber's experience and tribological expertise when it comes to lubrication, corrosion protection and maintenance under taxing conditions. Even in today's widely used turbines with a power output of 2 to 3 MW, conventional lubricants are tried to their limits. Turbines designed to generate 5 MW pose conditions that are simply too much for the lubricants as described in various international standards, not to speak of the 10 MW units that are already being tested.

Still, the role of lubricants is widely underestimated in the wind energy sector, although it has a decisive influence on the performance, efficiency, maintenance requirements and service life of the equipment. An additional aspect to consider in wind power stations is that maintenance and repair jobs often have to be carried out under adverse conditions. This problem will be aggravated in the high-capacity offshore wind parks that are going to be built, e.g. when unplanned maintenance becomes necessary during unfavourable weather. If conditions are too harsh, a defective component may even mean that the turbine is forced to remain idle for some time - downtimes of several months are quite conceivable. High-grade lubricants can help to prevent such failures and extend maintenance intervals. If just a single inspection is rendered unnecessary, this will compensate for the total lubricant costs arising during the whole service life of a plant.

Already today, thousands of wind power plants worldwide are lubricated with high-performance products made by Klüber, while others are about to switch over. Renowned turbine and component manufacturers use products developed by Klüber for initial fill and recommend them to operators.

Special solutions for gaining energy from the wind
The lubricants used in wind turbines are expected to offer constant high load resistance and good thermal stability throughout a long service life, which shows itself, for example, in the form of long relubrication intervals. Some figures for comparison: whereas in a private car the engine oil has to be replaced after 15000 to 25000 km, corresponding to 300 to 500 operating hours at an average speed of 50 km/h, the oil change in a wind turbine main gearbox is due only after 25000 to 50000 operating hours.

Another peculiarity of wind power plants is that the bearings in a wind turbine unit - main bearing, generator bearing, slew ring and blade pitch bearings - operate under highly varied conditions, so the lubricants have to cater for a set of very different requirements. While the main bearings rotate slowly, but are subject to high loads and vibrations, the generator bearings have to cope with high speeds as well as high temperatures. The blade pitch bearings and slew rings are again exposed to high loads and vibrations, and in addition they have to withstand the particular strains of oscillating motion. External influences come on top of all that: extreme temperatures and temperature fluctuations, salty air near the coast and offshore, constantly changing weather and, not to be forgotten, the forces acting on the bearings even during turbine standstill due to the micro-movement of the blades.

Individual development partnerships, comprehensive test procedures
In many components - in wind power plants as well as in all other branches of industry - the lubricant has a decisive role as a design element in its own right. Wherever machine elements move against one another, lubricants reduce friction and wear, thus influencing the function of the component. Klüber attaches major importance to the close cooperation between the component maker and the lubricant manufacturer at an early stage of any new development. Klüber initiates individual development partnerships in order to optimise products for the customer, generate or extend innovative headway, increase productivity and save costs.

What helps Klüber to do this, besides its R&D competences, is its unique test bay enabling mechano-dynamical tests on more than 100 test setups. This is where the performance capabilities of Klüber's lubricants are put to the test - by standardised DIN, ISO or ASTM tests, on test rigs developed by Klüber, or by means of individual component tests.

As Klüber develops and produces its lubricants in its own facilities specifically for each individual industrial sector, customers worldwide can count on competent contact persons who know and understand the topics and challenges in the various industries and the local markets, which enables them to provide always top-class application consulting.

About Klüber Lubrication

Klüber Lubrication is one of the world's leading manufacturers of speciality lubricants, offering high-end tribological solutions to virtually all industries and markets worldwide. Most products are developed and made to specific customer requirements. During its more than 80 years of existence, Klüber Lubrication has provided high-quality lubricants, thorough consultation and extensive services, which has earned it an excellent reputation in the market. The company holds all common industrial certifications and operates a test bay hardly rivalled in the lubricants industry.

Klüber Lubrication, set up as a retail company for mineral oil products in Munich in 1929, is today part of Freudenberg Chemical Specialities SE & Co. KG, a Business Unit of the Freudenberg Group, Weinheim. In 2011, Klüber Lubrication had approximately 1900 employees in more than 30 countries.

Press contact
Klüber Lubrication München
Andreas Hasslinger, Marketing Communications
Geisenhausenerstr. 7
81379 München
Tel.: +49 89 78 76-467

Michael Jurischka
Gotzkowskystr. 11, 10555 Berlin
Tel.: +49 30 28 44 95 95