Case Studies

Weight is a major technical challenge for wind turbine manufacturers. The greater the weight of the nacelle components and rotor, the stronger the tower structure required and the greater the problems of transportation and erection. Approximately 20% of the mass of a wind turbine is associated with the gearbox, the largest single contributor after the blades. Inadequate stiffness in the gearbox casing can result in misalignment of gears and bearings, causing noise, vibration & premature failure.

This project will seek to determine the feasibility of a major reduction in gearbox weight, by replacing the cast iron casing with aluminium, locally reinforced with advanced composite material to provide enhanced strength and stiffness. This should deliver a weight saving of around 45% for the casing, equivalent to over 25% for the complete gearbox – in excess of 4 tonnes for a 2MW turbine. In addition, the project will investigate weight reduction opportunities in the rotating components, such as the planetary gear carrier. Use of the aluminium matrix composite (AMC) material will also produce an increase in local stiffness to reduce the misalignment of bearings and gears under load, improving durability.

The technology delivered by this project will provide significant competitive advantage to a manufacturer of turbine gearboxes. David Brown has identified the offshore wind market as of strategic importance to its future growth plans and is driven both to enter this market with new build product and support the industry long term via its aftermarket operations. By pursuing lightweight gearbox assemblies, David Brown will develop a competitive advantage that can be leveraged together with its location within the Northern supply chain area. Local suppliers will benefit from this strategic development, for example in the manufacture of aluminium castings for gearbox casings. The majority of the workforce for the assembly plants will be recruited locally, as will the engineering staff.

David Price
Commercial Director

Composite Metal Technology Ltd
Prisma Business Park, 3 Berrington Way
Basingstoke, Hampshire
RG24 8PL, UK

Tel: +44 (0)1256 477741
Email: dave.price@cmt-ltd.com
Website: www.cmt-ltd.com