Case
Monitoring ensures fast Action and maximum Uptime
For one of our existing customers for whom we provide technical support, several indications of alarming wear and tear in a wind turbine’s main gear was observed.

What is it?
We identified and repaired alarming wear and tear on a wind turbine’s main gear.
What did we do?
We identified the challenge, planned and ensured that the entire process went accordingly.
What was the outcome?
The repairs were carried out focusing on the wind turbine’s remaining lifetime. We optimized our customer’s investment by minimizing days of lost production and eliminating future costs.
From chaos to project management
For one of our existing customers for whom we provide technical support, we observed several indications of alarming wear and tear in a wind turbine’s main gear.
The gear is equipped with an external monitoring system, where different sensors measure the vibration level of the main bearing, gear and generator. A filter analysis of the oil filter from the gear in question, showed that the gear contained metal particles.
Occurrences of metal particles in such analyses increase when damages develop in either the bearings or gears. By being warned at an early stage of an alarming wear and tear of a main component, the risk of the wind turbine being inoperative for a prolonged period is minimized. Without early warning, worst case scenario could be total destruction where none of the main components can be reused afterwards.
Observed deviations
No matter what type of component needs to be replaced, we offer to negotiate the best deal from several suppliers on the market. This is always done according to best practice.
For this specific task, we prepared an estimate of the main gear’s expected remaining lifetime and worked from this time horizon to minimize downtime in connection with the replacement. Momentum is responsible for obtaining and negotiating several different offers on behalf of our customer. We do this in order to obtain the best overall price for fitters, cranes, transportation, repair of the existing access roads, etc.
Recommendation and replacement
Based on the mentioned vibration measurements, it was our clear recommendation to reuse the main bearing. This component is part of the complete drive train consisting of gear, main shaft and main bearing. The complete drive train is dismantled in connection with the replacement of the main gear.
The main bearing on this type of wind turbine is quite expensive, and in this case, there was no evidence of abnormal wear. Thus, the main bearing is expected to be able to last throughout the lifetime of the wind turbine.
Due to the size of the main bearing and for reuse purposes, we ensure that it is dismantled under proper conditions. This helps to reduce the risk of errors in connection with the actual dismantling of the gear and main shaft.


Advice according to customer's wishes
In several cases, our customers want us to be present during the actual replacement, either partially or from start to finish of the process to supervise every step. In these cases, we perform thorough quality assurance on the work being done.
When the rotor was disassembled, a major damage was observed to one of the “tippers” of the blades. The tippers are the braking function on this type of wind turbine.
By being present during the process, Momentum quickly took action and ensured that the damage was repaired immediately.
As the customer has a large portfolio of this type of wind turbine, the gear needs to be renovated in a quality that corresponds to the expected lifetime of the wind turbine. Once the defective gear is disassembled, Momentum conducts an inspection if requested by the customer. The inspection is performed in order to assess and decide on the best solution for repairing the defective gear
Hard Facts
When we perform technical monitoring of the customer’s turbines, it is our job to continuously analyze the condition of the assets. When doing this, we are always at the forefront when ordering main components before replacement is required. This typically reduces lost production from 3-4 weeks to 2 days.
In this specific case we saved the customer 1 day of lost production. Momentum was present during the whole replacement process and thus discovered a damage on the blade tippers, when the rotor was already dismantled. If this had not been discovered and the blade subsequently needed repair, besides lost production, the customer would also have to face additional costs related to the lifting equipment that are used for these kinds of repairs. The saving estimate is around DKK 12.000.
