Transcript PPT
Challenges in Wind Turbine Components Charles D. Schultz, PE Beyta Gear Service Winfield, Illinois What is going on in Wind Energy? Activity on a national scale Progress has been made but much remains to be done! It is all about jobs! Domestic Content Progress US Wind Resource Map • US is the “Saudi Arabia” of wind • Transmission of power from central plains to coasts is a problem • Even states that aren’t “colorful” have wind potential Examples of Components • Blade Hubs are huge castings – up to 15,000 pounds • Gearbox Assemblies weigh up to 60,000 pounds and are getting larger • Chassis are big fabrications or castings – up to 40,000 pounds and getting larger Towers & Blades • Transport issues, 50 meter lengths & 40 ton weights • High cost items • Potential for big improvements • Big incentive to make locally Big Market, Long Term Potential Where are the problems? Quality is a given • Due to high cost of warranty work all parts have strict quality specifications • Tolerances test equipment capabilities • Documentation requirements similar to aircraft industry • Little acceptance of non-conformances • Metallurgical cleanliness at aircraft levels • Expect to cut up lots of samples for metallurgical checks Consistency is Mandatory • Expect customers to dictate suppliers, methods, and even tooling • Customers will have quality observers in your facility • Once a method is approved changes are difficult to make • Rework –especially in thermal processingis subject to extreme scrutiny Big portion of value is in the Nacelle Large, precision gearboxes required • Aerospace precision in a mining machine sized package • Quality levels far in excess of industrial equipment • Huge warranty and maintenance costs Other Geared Products Planetary designs predominate Typical Gearbox Parts Typical Pinion • Not dissimilar to industrial gearing • Large cross sections challenge heat treat response • 18CrNiMo7-6 typical material • Current weights up to 2500 pounds and getting bigger Typical Sun Pinion • Large thru hole helps heat treat response • 18CrNiMo7-6 typical material • Heat treat distortion common • Current weights up to 2000 pounds and getting bigger Typical Gear • Not dissimilar to industrial gears • Large cross sections challenge heat treat response • 18CrNiMo7-6 typical material • Super finishing issues • Current weights to 10,000 pounds and getting bigger Typical Splined Hub • Typically thru hardened but some nitrided or induction hardened • Length [up to 30”] is a shaping challenge • 42CrMo4 typical material • Current weights up to 2500 pounds and getting bigger Typical Ring Gear • • • • As large as 3 meters Many thru hardened Nitriding popular Induction hardening is also used • Carburizing possible but problematic • Shot peening and super finishing issues Typical Planet • Lots of planets needed; 3, 4, or 5 per stage • Precision size matching within sets • 18CrNiMo7-6 typical material • Current weights up to 2200 pounds and getting larger Serial Production – not job shop! • 7,000 turbines per year = 27 per day • 10,000,000 cars per year = 38,462 per day • Typical large industrial gear shop does less than 5 gearboxes per day • Aircraft production –similar in quality and complexity – is on the order of 1000 per year Thermal Processing Issues • Large parts require large furnaces • Economic load sizes typically over 5,000# • Large teeth require deep cases • Cycle times of 60+ hours not uncommon • Aerospace quality required at all steps Volume & price pressure drive equipment purchases • Customers want lowest possible costs • Existing job shop equipment can’t keep up • New technology offers improved quality with faster cycle times Dramatic Cycle Time Reductions Possible • Shaping an internal ring takes 30 hours • Gashing takes 3 hours • Hobbing a gear can take 8 to 10 hours • Gashing takes less than 2 hours Big non-chip making investments needed • • • • • • SPC needed on everything 100% magnaflux, UT, & nital etch typical Shot peening required on everything Full met lab checks on every furnace load Verification of geometry requires big CMM Everything that can be inspected must be inspected Big investments needed in QC Super Finishing required on many components To achieve 4 to 8 AA surface finish An Industrial Challenge worthy of a great nation! • • • • Potential to transform the economy Positive environmental impact Huge export market available US was once the world leader in wind energy and can be once again • Plenty of room for innovation at all levels of the business