Liebherr produces well-engineered mechanical systems for rotor blade adjustment. Electric pitch systems are based on one or more mechanical gear units with electric motor, which drive a geared large diameter slewing bearing.

Hydraulic pitch systems are based on one or more hydraulic cylinders and a slewing ring bearing without gears to adjust the rotor blade position. In either case, the precise positioning of the rotor blades results in maximum energy yield.

In pitch systems, the following components from the Liebherr portfolio can be applied:

• Large diameter bearings
• Gearboxes
• Hydraulic cylinders
• Electric motors
• Integrated lubrication system

Three-row roller bearings for higher load capacity and more cost efficiency

Wind turbines are growing steadily in an effort to attain higher energy yields. The options of adapting existing designs to the growing dimensions and more demanding load profiles has however limits - particularly in regard to rotor blade bearings. Therefore, in addition to the current single-row and double-row four-point bearings, Liebherr now also offers three-row roller bearings for pitch systems. This highly increases the potential in terms of dimensioning and load capacity.

Depending on the specific system design, up to twelve or more high-performance planetary gearboxes drive a slewing bearing and ensure precises as well as reliable wind direction tracking. Liebherr configures the entire yaw system, including the necessary electric motors, precisely to the needs of the customers. This guarantees a high level of system availability.

The following components from the Liebherr portfolio are ideally suited for use with yaw systems:

• Large diameter bearings
• Gearboxes
• Electric motors
• Integrated lubrication system

Yaw module concept study

In the course of the last 20 years, variety of parts and complexity have steadily increased within the wind industry. With this study, Liebherr wants to show new ways to achieve more flexible yaw system. The result is a module which integrates all functions of the yaw system in a ready-to-install unit.

The current concept offers a wide range of advantages. It can be easily scaled in terms of size and capacity and adapted to the different turbine platforms. Additionally, the use of standard components across all platforms hold great cost savings potential. Further, the implementation of the yaw system as a ready-to-install module makes it possible to simplify processes for the turbine manufacturer along the entire value chain.

The right design and analysis of a component is decisive for its reliability and service life. For multi-megawatt wind turbines a design using Finite Element Methods (FEM) is essential, as the sensitivity to strain increases the larger the system gets. In addition, defined approval processes for new and further developments ensure optimal product configuration and thus high reliability.

In order to ensure consistent high quality and reliability, all manufacturing processes must be optimally aligned. Hence why Liebherr improves all production processes on an ongoing basis and continually invests in cutting-edge production facilities.

Reliable components with a consistently high quality are particularly important for wind turbines in order to avoid long production downtimes and high logistics costs. To ensure that the quality standards achieved in the construction using Finite Element Methods (FEM) and Failure Mode Effects Analysis (FMEA) are also maintained in subsequent processes, all company processes are designed to maintain quality.