Wind Turbine Gearbox Gear Repair Case Study

Client Background#

A wind farm operation and maintenance (O&M) company operates 2 MW wind turbines. During service, pitting failure was found on the gears of the speed-increasing gearbox of one of its turbines. The speed-increasing gearbox is a key component in the turbine drivetrain, and once its gears fail, the turbine cannot continue to run normally. The gears were of imported origin, and no spare parts inventory was held on site, so the customer needed the problem handled as an emergency repair.

Requirement & Challenge#

• Tooth surface pitting area had reached 30%, which affects operational safety and ruled out continued operation.
• Lead time for new gear procurement is 6 months — for a wind farm, that means a long stop plus a long wait.
• No spare parts inventory for imported gears, so a like-for-like replacement was not available at short notice.

Taken together, the usual route — ordering a new gear set from the original supplier — was not workable. What the customer needed was a repair route that could be carried out locally and quickly, while restoring the original design intent of the gear pair rather than simply producing a geometrically similar part.

Solution & Process#

1. On-site Measurement: Specialists conducted measurement on site, with the equipment in its installed state, to obtain original data directly from the machine instead of relying on incomplete drawings.
2. Reverse Engineering: Based on the worn tooth profile and the measured data, the original design parameters were back-calculated. This gave a reliable basis for manufacturing gears that would mesh correctly with the mating parts already in service.
3. Rapid Manufacturing: Once the parameters were confirmed, production was expedited and the gears were delivered in 4 weeks.

The measurement, reverse engineering and manufacturing steps were linked into one continuous workflow, so no time was lost waiting between stages.

Result & Feedback#

• The job was completed from measurement to delivery in 4 weeks.
• Cost was only 50% of new procurement.
• One year of operation tracking after the repair showed good performance.