The component was manufactured for one of the 11 Bonus 450kW turbines that were first commissioned at Vindeby in 2001.
It is minuscule in comparison with gearbox for the 8MW Adwen offshore turbine that Winergy showed for the first time at the WindEnergy Hamburg event last year.
A former Vindeby service technician stopped by and recognised the gearbox
The Vindeby gearbox on Winergy's stand is exhibited in the state at which it came out of the turbine. It was in operation for 25 years without failure, the firm said.
"Now that Germany's wind shows are split between Hamburg and Husum, we take a different approach to what we exhibit," said Winergy communications manager Tobias van der Linde.
"Hamburg is the technology showcase; at Husum we concentrate on our repair and maintenance services," he said, admitting that a gearbox that hadn't required any repairs over 25 years might seem a curious way of promoting Winergy's O&M offerings.
Winergy's 8MW gearbox on display at WindEnergy Hamburg 2016