Challenges in Wind Turbine Components

1. Challenges in Wind Turbine Components Charles D. Schultz, PE Beyta Gear Service Winfield, Illinois

2. What is going on in Wind Energy?

3. Activity on a national scale

4. Progress has been made but much remains to be done!

5. It is all about jobs!

6. Domestic Content Progress

7. 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 US Wind Resource Map

8. 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 Examples of Components

9. Transport issues, 50 meter lengths & 40 ton weights High cost items Potential for big improvements Big incentive to make locally Towers & Blades

10. Big Market, Long Term Potential

11. Where are the problems?

12. 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

13. 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 processing- is subject to extreme scrutiny

14. Big portion of value is in the Nacelle

15. Aerospace precision in a mining machine sized package Quality levels far in excess of industrial equipment Huge warranty and maintenance costs Large, precision gearboxes required

16. Other Geared Products

17. Planetary designs predominate

18. Typical Gearbox Parts

19. 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 Pinion

20. 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 Sun Pinion

21. 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 Gear

22. 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 Splined Hub

23. 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 Ring Gear

24. 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 Typical Planet

25. 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

26. 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 Thermal Processing Issues

27. 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

28. 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

29. 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

30. Big investments needed in QC Super Finishing required on many components To achieve 4 to 8 AA surface finish

31. 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