Case study: Service life cycle example

Case studies November 7th 2017

Services spanning from predictive maintenance to up-tower repairs

Moventas high-qualified technicians and engineers can perform up-tower repairs even on non-Moventas gearboxes. Moventas team in Italy has recently completed successfully an up-tower repair on a 2 MW wind turbine. The work included the replacement of intermediate shaft (IMS) assembly and high-speed shaft rotor side bearing (HSS RS).

The defects were initially detected by our remote Condition Management System – CMaS, which keeps a watchful eye on seven key parameters: temperature, vibration, load, pressure, RPM, oil condition and oil particles. Thanks to CMaS, it was possible to prepare the maintenance activity largely in advance, minimizing the downtime of the turbine and preventing further failures of the gearbox components. CMaS showed an increasing of the overall parameters, such as the acceleration values (figure 1 and 2) and the cumulative oil particles (figure 3).

Moventas’ service offering through the life cycle:

A deeper vibration analysis revealed a defect on the inner race of HSS RS bearing and on IMS pinion.

The endoscopic inspection confirmed the results of the vibration analysis. A broken tooth was detected on the IMS pinion and the HSS RS bearing was found in bad condition. Widespread indentations were detected on the outer race, as well as initial spalling. Rolling elements were affected by polishing.Unfortunately, the inner race could not have been inspected.

Following the vibration analysis and the endoscopic inspection, Moventas technicians performed the replacement of IMS assembly and HSS RS bearing.Moventas has developed special tools for replacing the HSS RS bearing without extracting the entire high-speed shaft, which saved time and reduced the costs.