Clipper Libery Gear Failures

The Clipper designed “Quantum Drive” gear boxes problems has almost nothing to do with the quality of the individual helical gears being assembled by a subcontractor as previously reported. This is not a Serial Defect quality failure story, it is a total Engineering Design failure of the whole “distribute loading” concept of the complex gear box. They did not follow standard accepted engineering practices which would allow the gears the proper degrees freedom necessary to relieve stress and strain in the system coming from the driving torque and from thermal expansion of the gears and case. Specifically, the four sets of gears are physically radially constrained in a closed loop meshing of all gears to back the main bull gear. Their distributed loading idea does not work because of variables acting in this distributed meshing. Axially the gear and pinion float would be acceptable as the double helical gears track and counter gear thrust. Radially however, the gears are totally constrained and have a cascading additive tolerance build up that changes as the gears wear in and what is more important, as they expand due to the friction heat losses being absorbed into the box coming from from a variable generator load of up to 2.5Mwatts. The box also has a input cold side a hot side where the generator is flanged, exhausting and conducting waste heat directly to the box adding another variable into the equation. It takes more than computer driven precision gear cutting machining to solve these problems.

Clipper's latest attempt to “distribute load” and get away with using smaller gears and fewer stages is as wrong as the original patent. They called this fix, the “legacy failure” (Someone else's fault? How unfunny!). It would take an a extraordinary degree of accuracy to avoid a progressive tolerance build-ups stressing the weakest link which are the pinions. They are trying to skip a gear reduction stage by using small pinion gears driven by much larger gears. Given perfect gears, no wear or backlash and no thermal expansion this might work for a while. But warm this up about a 100 degrees and the secondary gears expand from both directions to pinch all the inner connected expanding pinion gears. As they wear in and warm up and expand, the ratios change ever so slightly to produce what they call “gear timing errors” which in reality is “the gashing of teeth”. It looks like in their attempt to distribute the load by 4x, they have actually engineered in a 2x or 4X overload situation if the "gear timing" changes (how do you adjust timing to fixed gearing). Also, since the box oil bath is common, any pinion failure will cascade through the box making it fail as one unit. In other words, they have all their pinions in one basket and there is no redundancy. This thing is a Pandora's box of reliability. It is no wonder they were failing in the first month.

What does all this mean, it means Clipper is finished and this is an embarrassment to American Industry. I apologize for being the messenger of such bad news.

REF:
CLIPPER WIND TURBINE GEAR FAILURES STOP "STEELWINDS" IN LACKAWANNA

http://xrl.us/bgznj

OHIO PROJECT ON HOLD WITH GEAR TIMING FAILURES:

DESCRIPTION, OF FAILED LEGACY FAILURE PROPOSAL TO ORIGINAL DESIGN