ISO 81400-4:2005

Foreword
1 Scope
2 Normative references
3 Definitions and symbols
4 Design specification
5 Gearbox design and manufacturing requirements
6 Lubrication
7 Other important items
Bibliography
Annexes
A - Wind turbine architecture
B - Wind turbine load description
C - Quality assurance
D - Operation and maintenance
E - Minimum purchaser and gearbox manufacturer
    ordering data
F - Lubrication selection and condition monitoring
G - General gear information
H - Determination of the application factor, K[A],
    from a given load spectrum using the equivalent
    torque, T[eq]
I - Bearing stress calculation

ISO 81400-4:2005 establishes the design and specification of gearboxes for wind turbines with power capacities ranging from 40 kW to 2MW. It is applicable to all such parallel-axis, one-stage epicyclic and combined one-stage epicyclic and parallel shaft enclosed gearboxes. Its provisions are based on field experience with wind turbines having the above power capacities and configurations; its guidelines can be applied to higher capacity wind turbines provided the specifications are appropriately modified to accommodate the characteristics of higher capacity wind turbines. Life requirements apply to wind turbines with a minimum design lifetime of 20 years.