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rothe erde® Pitch bearing – Reliable blade pitch adjustment for optimal energy conversion
Pitch bearings are the connecting elements between the rotor hub and the rotor blade of a wind turbine. To maximize power output from the generator at varying wind speeds, the pitch angle of the rotor blades must be adjustable. The primary functions of pitch bearings are to enable the blades to be adjusted, and to endure the high loads exerted on them.
The pitch bearings are subjected to heavy loads due to continuous load changes. To ensure reliable operation over the service life of the application, the pitch bearings from Rothe Erde are equipped with:
preloaded raceways,
wear-resistant cage inserts,
special ozone and UV-resistant double lip seals and
integrated internal or external gearing (on request).
Our rothe erde® pitch bearings undergo thorough inspection before delivery using advanced testing methods and efficient analysis tools. These tests provide us with essential data on load-bearing capacity, service life, performance, and operational limits.
You can also find out all about our modularization approaches here: Extender-bearing & Pitch Bearing Unit.
Our test rig for pitch bearings
Pitch Bearing Unit - The solution for modular pitch systems and standardized hub designs for future wind turbines
Manufacturers of wind turbines face numerous challenges: intense competitive pressure demands ongoing cost reductions and supply chain optimization. Additionally, the trend toward larger wind turbines and their components, such as rotor hubs and blades, results in increased system deformations that can substantially affect the service life and performance of the pitch bearings. Furthermore, the logistical requirements and transportation costs in the onshore sector are rising significantly due to the size of these components. We have identified these issues and developed a solution: The Pitch Bearing Unit.
Technical details and benefits
Pitch Bearing Unit explained: Everything you need to know
The Pitch Bearing Unit (short: PBU) is the newest breakthrough product solution from Rothe Erde in the wind energy sector. The PBU is a conical extender bearing unit that functions as an adapter, bolted between the hub and the rotor blades. It enables the installation of larger blades on the same hub size or allows for a significant reduction in hub dimensions while using the same blades. Additionally, it serves as an extra stiffness element.
This innovative solution enables targeted modularization of the entire pitch bearing unit, and standardizes the hub and blade adjustment drive across all product families. The hub design is simplified for production and optimized for size and weight. The Pitch Bearing Unit is customized to the OEM-specific hub design. The simplified hub design lowers machining costs, while the reduced hub dimensions decrease transportation costs.
The PBU significantly enhances the structural stability and rigidity between the hub and the pitch bearing, which is especially important for large, potentially flexible hub bodies. The optimized system rigidity provides substantial mechanical benefits for the operation of the pitch bearing. The hydraulic or electric blade adjustment system is directly integrated into the Pitch Bearing Unit. A key advantage is that the supply chains for the hub and pitch drive can be intentionally separated, resulting in significant savings in logistics costs and reducing the amount of machining and assembly work required.
The entire supply chain and on-site installation are simplified by a plug-and-play system. The blade adjustment system, whether hydraulic or electric, can be set and tested during the assembly of the PBU, significantly reducing the complexity and effort required for the final assembly of the wind turbine. As a pre-assembled complete unit, the PBU simplifies the overall installation process.
PBU – The cutting-edge innovation in wind energy from Rothe Erde
Extender bearings – Reduced assembly effort thanks to modularization
The extender bearing can function as a standard hub for various blade root diameters or maintain a consistent blade root diameter across different hubs.
Extender bearings in detail: function and application
The extender bearing is a slewing / rolling bearing in wind turbines that integrates both the blade bearing and a separate extender ring into one component.
The inner ring of the extender bearing features an inwardly tapered flange to which the wind turbine rotor blade is mounted. By changing the flange taper, different blade root diameters can be adapted without changing the design of the raceway system, the outer ring, etc.
The production of the extender bearing poses a particular challenge. Achieving the material properties in the highly stressed areas and tempering is difficult. The reason for this is its shape and the dimensions of the special inner ring.