EN 61400-4:2013

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms, definitions and conventions
4 Symbols, abbreviations and units
5 Design for reliability
6 Drivetrain operating conditions and loads
7 Gearbox design, rating, and manufacturing
  requirements
8 Design verification
9 Operation, service and maintenance requirements
Annex A (informative) - Examples of drivetrain
        interfaces and loads specifications
Annex B (informative) - Gearbox design and
        manufacturing considerations
Annex C (informative) - Bearing design considerations
Annex D (informative) - Considerations for gearbox
        structural elements
Annex E (informative) - Recommendations for lubricant
        performance in wind turbine gearboxes
Annex F (informative) - Design verification documentation
Annex G (informative) - Bearing calculation documentation
Bibliography
Annex ZA (normative) - Normative references to
         international publications with their
         corresponding European publications

IEC 61400-4:2012(E) is applicable to enclosed speed increasing gearboxes for horizontal axis wind turbine drivetrains with a power rating in excess of 500 kW. This standard applies to wind turbines installed onshore or offshore. It Standard provides guidance on the analysis of the wind turbine loads in relation to the design of the gear and gearbox elements. The gearing elements covered by this standard include such gears as spur, helical or double helical and their combinations in parallel and epicyclic arrangements in the main power path. The standard is based on gearbox designs using rolling element bearings. Also included is guidance on the engineering of shafts, shaft hub interfaces, bearings and the gear case structure in the development of a fully integrated design that meets the rigours of the operating conditions. Lubrication of the transmission is covered along with prototype and production testing. Finally, guidance is provided on the operation and maintenance of the gearbox.