Onshore wind turbine gearbox failure, published sun shaft fracture analysis
2024Published 1 May 2026Responsible editor: Chief Editor
- What
- Sun shaft fracture analysis of 1.6 MW onshore wind turbine gearbox
- Cause
- Not reported
Get the next one by email
Free alerts on wind (onshore) incidents worldwide, and an email when EIR-0054 is updated. No account needed; unsubscribe in one click.
Confirm your email and every wind turbine incident on the register arrives at once as a spreadsheet (CSV), free.
Get a free sample brief Three complete verified records and the incidents-per-GW table, by email within a minute.
We will also email you about the register's paid records and plans, at most once a week and three times in all. You can stop these at any time. By signing up you agree to the privacy policy.
What happened
A peer reviewed engineering paper published in January 2025 set out a failure analysis of the gearbox of an onshore wind turbine rated at about 1.6 MW. This entry is drawn from that published analysis rather than from an operator report, and the date and location of the failure itself are not stated here. The paper examined the sun shaft of the planetary stage, a component that carries high stress concentrations, and combined finite element stress analysis under operational loading, fracture mechanics assessment of the observed crack initiation and propagation, review of the lubrication system and its part in wear progression, and consideration of contributory factors across the wider gearbox.
The paper sits within a body of published work that identifies gearbox failure as one of the highest consequence reliability issues in onshore wind. Separate published fleet studies, not the paper cited here, report high speed shaft bearing failures as a leading share of gearbox subcomponent failures.
Contributing factors
The cited paper and the wider published literature discuss the following mechanisms as typically present in gearbox failures of this kind. They are reported here as mechanisms described in the sources, not as confirmed causes for this unit. (1) High speed shaft bearing wear associated with white etching cracks, a degradation mechanism reported in modern gearbox bearings, particularly under variable loading. (2) Lubrication system performance, including oil contamination from water or particulate ingress and oil temperature management. (3) Dynamic loading from wind turbulence, grid events and control system anomalies beyond static design load assumptions. (4) Manufacturing tolerances and assembly quality, with small variations propagating over many thousands of operating hours. (5) Limitations of condition monitoring, where vibration analysis, oil debris monitoring and acoustic emission may not detect early stage progressive damage. The literature describes gearbox condition monitoring as an area of active research rather than a settled capability.
Lessons learned
- High stress concentrations in the sun shaft of the planetary stage require fracture mechanics assessment of recovered parts.
- Lubrication system performance must be reviewed as part of gearbox failure analysis to check for wear progression.
- Condition monitoring limits mean early stage gearbox damage may go undetected under variable loading.
More lessons on structural integrity and turbines, from every incident on the register.
Not yet known
- Date and location of the failure
- Turbine model and age
- Downtime and cost of the failure
- Confirmed cause for this unit
This entry is updated when these are reported. Get an alert for the next one like it.
Source
Published 2026-05-01. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.
