If you can’t bring a damaged gearbox to the shop, Moventas will bring the shop to the gearbox. A few months ago, gearbox manufacturer Moventas took the wraps off its mobile service unit (MSU) which is actually a gear-repair shop in a trailer. This 20-ft. workshop-on-wheels let repair crews refurbish most of a gearbox without taking it into a shop. Field repairs usually complete in three days. That was a great improvement over the previous method that required a major and costly crane callout for who knows how long.
The company has more recently taken the wraps off version two of its work shop-on-wheels. The new design is about 30-ft long with a shop roof that retracts at the touch of a button, rather than manually as with the first version. The MSU V2 will have on-board power source and air supply. It also includes a wash basin, induction heater, and welding and cutting capabilities.
Four units will provide a clean and climate controlled working environment. “This will let us work on any gearbox,” says James Macik, Moventas’ general manager at the company’s Big Spring, Texas facility.
The nacelle has not been an easy place to work. ”We’ve changed all that. Now we can repair the helical sections in every Moventas gearbox, and all the way back to the planetary. We can do the high speed, intermediate, low speed, and it’s now possible to change the sun pinion as well, and in three days on site with use of a small crane,” says Macik.
A conventional change-out can cost up to $500,000 including crane, gearbox, and
manpower. Macik says his crews can reduce the repair cost to $40,000 on the gearbox. That does not cover the crane, he admits, but the smaller versions run from $20k to $30k. “We keep the crane time onsite to a minimum, and do every pick in one day.
A conventional or in-shop repair for a gearbox would also put it on load tester to check that all defects have been repaired. Because that is impossible in the field, Macik’s crew applies its CMaS (Condition monitoring a s) system on the unit and provides remote monitoring for a year after the repairs.
“We have four MSUs on the road around North America. They will be located 200 to 300 mi from major wind farms,” says Macik.
Additional up-tower services include end-of-warranty inspections, generator alignment, pitch-tube repairs on Windergy and Rexroth models, and bore- scope and vibration
inspection of all gear units.
What’s more, Macik’s team is also finding best practices for working in the MSUs. “For instance, a bag policy will be that when a gear comes down, it does so in a bag and goes back up in a clean bag.” WPE
Filed Under: Gearboxes, O&M