Gearbox Quandary

A PM (preventive maintenance) program that changes out the gearboxes in 6-10 years, adjusted by experience.

Consider the run time accumulated in that 7 to 11 year span. Around here those big wind generators run 24 hours a day 4 - 5 days a week. 24 x 4 x 52 x 7 = ~35,000 running hours. 24 x 5 x 52 x 11 = ~69,000 running hours. In mechanical life terms that a lot of run time even for massive gear sets and bearings. Plus all of those hours are put on while working in less than favorable or ideal conditions as well.

Very few industrial and commercial machines ever reach run time numbers close to those in their working lifetime.

Just for comparison your average vehicle may run for 200,000 miles or more but its run time in those 200,000 miles is still only a few thousand hours at best and take 10 - 20 years to accumulate.

We have mechanical areators that run 24/7 in waste treatment plant.Had a lot of bearing/gear wear after 5 or 6 years.Consulted with Wynn's Friction Proofing company.They analysed our lubricant and recommended a 25% mixture of Wynn's Friciton Proofing to our gearboxes.We followed recommendation, and we had zero bearing,gear failures for over 20 years.Motor failures, paddle bearing failures,etc, but not in out gearboxes.

It has been at least 20 years since I have worked in the field, and waste treatment plants have now changed to compressed air aeration instead of mechanical agitation.

In short, the answer seems to be in improved lubrication of the gerarboxes to extend service life, and close monitoring of preventative maintenance protocols.

If properly designed,and properly serviced, a gearbox should run basically a lifetime.

And, by the way, I add 1 can of friciton proofing every oil change,when I can find it.Getting hard to find nowadays.

The 'newer wind turbines' do not have gearboxes.

Rather like the 'newer cars' don't have crank-handles

Or the newer houses have 'indoor plumbing'.

Recently they have developed a hydraulic drive instead of gearbox and located the generator at ground level

Different technology I know but the windmill down the road from me is 300 years old & although not original the gears & shafts are a lot more than 20 years old can we learn something from this 'old' technology?

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