Cyclo drives in yaw, pitch drives for wind turbines

Supplier: Sumitomo Drive Technologies
06 September, 2012

With its comprehensive drive technologies, the company (Sumitomo Cyclo Drive Germany, GmbH) offers solutions for a wide range of applications.

When it comes to tailor-made pitch and azimuth drive solutions, wind turbine providers benefit from the close proximity to the German development and production facilities, while worldwide users benefit from the high-quality on-site service of the global brand Sumitomo Drive Technologies.

Leading drive solutions, worldwide service

Sumitomo Drive Technologies' product portfolio comprises standard drives as well as customised modifications to proven products. With more than 75 years of experience in drive technology, the company offers consultation, development and the production of custom-made drives from a single source.

Its massive international expansion began more than thirty years ago with the involvement of the Japanese group Sumitomo Heavy Industries (SHI). As a subsidiary, Sumitomo (SHI) Cyclo Drive Germany GmbH today offers highly qualified services to worldwide customers.

Cyclo: high technology with German tradition

Whereas conventional gearboxes rely on sliding tooth contact, with Cyclo drives the torque is transferred using an eccentric bearing assembly, cycloid discs and a fixed ring gear.

In contrast to conventional spur gears in which a few gear teeth have to absorb the entire loading, with cycloidal drives the load is distributed across at least 30 per cent of the cycloid disc profiles. This means that a Cyclo drive is also capable of withstanding momentary, intermittent shock overloads in extreme emergency situations.

High efficiency with reduced operating noise

In addition, the Cyclo principle leads to high-performance, compact and easy to mount drive configurations that feature high drive transmission ratios. The transmission ratios of single-stage drives range between 6:1 and 119:1, while three-stage drives can even achieve drive transmission ratios greater than 1,000,000:1.

The rolling action enables the torque to be transferred with minimum friction. Compared to traditional spur gear units, this reduces not only the thermal loading and the operating noise but also provides greater efficiency – even with high transmission ratios. The overall efficiency of single-stage drives is around 95 per cent.

Innovative drive solutions for wind turbines

The decisive factors determining the efficiency and durability of wind turbines are the pitch and azimuth drives, which can be particularly efficiently implemented with Sumitomo Cyclo drives.

Pitch drive solutions

Low-maintenance and compact pitch drives in the wind turbine's nacelle set the precise pitch angle for the rotor blades. Aligning the blades using precise, highly robust Sumitomo drives ensures that optimal efficiency is achieved even with low wind speeds and prevents damage to the wind turbines even with high wind speeds.

Yaw drives for the azimuth system

To enable the nacelle to track the wind horizontally, Sumitomo Cyclo Drive also offers proven azimuth drive solutions with compact drives for the high transmission ratios required here.

Advantages of pitch and azimuth drives

For both applications, the excellent efficiency, high durability and consequently long service life are particularly advantageous.