Already a subscriber? 
MADCAD.com Free Trial
Sign up for a 3 day free trial to explore the MADCAD.com interface, PLUS access the
2009 International Building Code to see how it all works.
If you like to setup a quick demo, let us know at support@madcad.com
or +1 800.798.9296 and we will be happy to schedule a webinar for you.
Security check
Please login to your personal account to use this feature.
Please login to your authorized staff account to use this feature.
Are you sure you want to empty the cart?
IEC 61400-4:2025 Wind energy generation systems - Part 4: Design requirements for wind turbine gearboxes, 2025
- CONTENTS
- FOREWORD
- INTRODUCTION
- 1 Scope
- 2 Normative references
- 3 Terms, definitions, abbreviated terms, units and conventions [Go to Page]
- 3.1 Terms and definitions
- 3.2 Abbreviated terms and units
- 3.3 Conventions [Go to Page]
- 3.3.1 Shaft designations – examples for typical wind turbine gearbox architecture
- 4 Design process [Go to Page]
- 4.1 General
- 4.2 Gearbox type
- 4.3 Design life, service life, and reliability
- 4.4 Component class and consequence of failure
- 4.5 Design process
- 5 Gearbox interfaces and loads [Go to Page]
- 5.1 General
- 5.2 Interfaces
- 5.3 Loads
- 5.4 Drivetrain dynamics [Go to Page]
- 5.4.1 General
- 5.4.2 Model requirements
- 5.4.3 Required analyses
- 5.4.4 Evaluation of excitability
- 5.4.5 Verification of dynamic behaviour in system environment
- 6 Design and rating requirements [Go to Page]
- 6.1 Gears [Go to Page]
- 6.1.1 Reliability considerations
- 6.1.2 Calculation of gear load capacity
- 6.1.3 Load factors
- 6.1.4 Materials
- 6.1.5 Accuracy
- 6.1.6 Manufacturing
- 6.2 Rolling bearings [Go to Page]
- 6.2.1 Reliability considerations
- 6.2.2 Bearing selection
- 6.2.3 Materials
- 6.2.4 Interface requirements
- 6.2.5 Design considerations
- 6.2.6 Bearing lubrication
- 6.2.7 Rating calculations
- 6.3 Plain bearings [Go to Page]
- 6.3.1 Reliability considerations
- 6.3.2 Design load cases and associated risks
- 6.3.4 Shaft and housing fits
- 6.3.5 Hydrodynamic lubrication regime
- 6.3.6 Lubricant regime analysis
- 6.3.7 Bearing requirements
- 6.4 Shafts, keys, housing joints, splines, and fasteners [Go to Page]
- 6.4.1 Shafts
- 6.4.2 Shaft-hub connections
- 6.4.3 Shaft seals
- 6.4.4 Fasteners
- 6.4.5 Bolted joints
- 6.4.6 Circlips
- 6.5 Structural elements [Go to Page]
- 6.5.1 General
- 6.5.2 Interfaces, boundary conditions, and loads
- 6.6 Lubrication [Go to Page]
- 6.6.1 General
- 6.6.2 Lubricant performance characteristics
- 6.6.3 Lubricant viscosity
- 6.6.4 Method of lubrication and cooling
- 6.6.5 Quantity of lubricant in the lubrication system
- 6.6.6 Operating temperatures
- 6.6.7 Temperature control
- 6.6.8 Lubricant condition monitoring
- 6.6.9 Lubricant filtration
- 6.6.10 Ports
- 6.6.11 Lubricant level indicator
- 6.6.12 Magnetic plugs
- 6.6.13 Breather port
- 6.6.14 Flow sensor
- 7 Design verification and design validation [Go to Page]
- 7.1 General
- 7.2 Design verification and validation plan
- 7.3 Failure mode categorization
- 7.4 Verification methods [Go to Page]
- 7.4.1 General
- 7.4.2 Testing
- 7.4.3 Similarity
- 7.4.4 Simulation
- 7.5 Verification and validation matrix
- 8 Manufacturing and quality assurance [Go to Page]
- 8.1 General
- 8.2 Quality plan [Go to Page]
- 8.2.1 General
- 8.2.2 Surface temper inspection of gears after grinding
- 8.2.3 Surface roughness inspection
- 8.3 Critical processes
- 8.4 Statistical process control
- 8.5 Factory acceptance testing [Go to Page]
- 8.5.1 Test objectives
- 8.5.2 Acceptance test plan
- 8.5.3 Factory test sequences
- 8.5.4 Acceptance measurements
- 8.6 Non-conforming components [Go to Page]
- 8.6.1 General
- 8.6.2 Grinding notches
- 9 Design for service and operation [Go to Page]
- 9.1 General
- 9.2 Service and operation design requirements
- 9.3 Service and operation documentation requirements
- 9.4 Safety
- Annex A (informative) Examples of drivetrain interfaces and loads specifications [Go to Page]
- A.1 General
- A.2 Common wind turbine drivetrain architectures [Go to Page]
- A.2.1 Non-integrated drivetrain with 4point suspension
- A.2.2 Non-integrated drivetrain with 3point suspension
- A.2.3 Integrated drivetrain
- A.2.4 Interfaces
- A.2.5 Coordinate system
- A.2.6 Interface descriptions
- A.2.7 Engineering data at the interface
- A.3 Wind turbine load descriptions [Go to Page]
- A.3.1 Load description formats
- A.3.2 Rainflow matrices
- A.3.3 Load revolution distribution
- A.3.4 Extreme load descriptions
- A.4 Wind turbine reference power and speed [Go to Page]
- A.4.1 General
- A.4.2 Wind turbine power control theory
- A.4.3 Practicalities of power control
- Annex B (informative) Dynamic gearbox model verification and validation [Go to Page]
- B.1 General
- B.2 Verification of drivetrain dynamics models
- B.3 Validation of drivetrain dynamics models
- Bibliography
- Figures [Go to Page]
- Figure 1 – Shaft designation in 3-stage parallel shaft gearboxes
- Figure 2 – Shaft designation in 3-stage gearboxes with one planet stage
- Figure 3 – Shaft designation in 3-stage gearboxes with two planet stages
- Figure 4 – Shaft designation in 4-stage gearboxes with three planet stages
- Figure 5 – Design process flow chart
- Figure 6 – Definition of planet gear rim thickness
- Figure 7 – Examples of bearing selection criteria
- Figure 8 – Notional operational conditions and plain bearing risk regions
- Figure A.1 – Non-integrated drivetrain with 4point suspension
- Figure A.2 – Non-integrated drivetrain with 3point suspension
- Figure A.3 – Rotor-side integration with rigid main shaft connection
- Figure A.4 – Rotor-side integration with flexible main shaft connection
- Figure A.5 – Generator-side integration with rotor support in generator
- Figure A.6 – Generator-side integration with rotor support in gearbox and generator
- Figure A.7 – Generator-side integration with rotor support in gearbox
- Figure A.8 – Example of rainflow cycles per design load case
- Figure A.9 – Example of a load revolution distribution
- Figure A.10 – Wind turbine power control regions
- Figure A.11 – Ideal power and speed control strategy
- Figure A.12 – Control strategy compared to actual response
- Tables [Go to Page]
- Table 1 – Definition of a gearbox type
- Table 2 – Minimum safety factors for pitting resistance and bending strength
- Table 3 – Mesh load factor for planetary stages
- Table 4 – Required gear accuracy
- Table 5 – Typical temperature differences for calculation of operating clearance
- Table 6 – Bearing lubricant temperature for calculation of viscosity ratio
- Table 7 – Guide values for maximum contact stress
- Table 8 – Plain bearing risks coupled to operating conditions
- Table 9 – Minimum safety factors
- Table 10 – Failure mode categorization
- Table 11 – Verification and validation matrix
- Table A.1 – Analysis information at interfaces for non-integrated drivetrains
- Table A.2 – Analysis information at interfaces for integrated drivetrain
- Table A.3 – Engineering data and design load descriptions
- Table A.4 – Rainflow matrix example
- Table A.5 – Extreme load matrix example [Go to Page]
