Alessandro Bozzolo

1. Wind Turbine Gear Drive-Trains Based on New Materials and Novel Gear SystemsConference, EWEC 2009Marseille18th March 2009 Alessandro Bozzolo

2. Maintenance problems related to wind turbine gearboxes • Maintenance of wind turbines is characterized by: • Difficulties related to the remote location where wind turbine are frequently installed • Difficulties in reaching the nacelle http://mrgreenbiz.wordpress.com http://www.tdhvisions.com

3. The need of more efficient gearboxes • Gear wear, if not caught in time, can cause serious collateral damage affecting the other parts of the drive-train and the generator • Gearbox failures account for the largest amount of downtime, maintenance and lost production capacity http://windtechireland.com

4. X-GEAR Project • Within this framework, the aim of the X-GEAR Project is the development of novel technologies and materials for a new generation of wind turbine gearboxes X-GEAR is a Collective Research Project (COLL-CT-2006 030433) financed by the European Commission

5. Partnership Transnational consortium partners: 7 Industrial Association Groupings (IAGs), 11 Small Medium Enterprises (SMEs), 4 Research and Technology Development Performers RTDs (Co-ordinator)

6. Participants Geographic distribution

7. The enabling technologies • Development of novel materials (new air-hardening steels, advanced sintered steels and UDDP nanopowders) • Development of novel coatings and surface treatments • Design Tool Development (database of materials, interactive guidelines, gear design procedures, e-learning and e-training module, etc.) • Novel Gears for wind turbine applications (novel steels / coatings, manufacturing routes, design aspects)

8. X-GEAR Project Structures Material Development Novel Surface Treatments Novel Gear Design and Manufacturing Production of Demonstrators Testing of Novel Gears Development of Design Tools Training Activities Exploitation and Dissemination Activities

9. Material Development Air-Hardening Steels • Air-Hardening Steel: steel containing sufficient carbon and other alloying elements to fully harden to martensite during cooling in air • Two steels are being analysed: OVATEC 277L (case-hardening steel) and OVATEC 677L (through hardening steel) www.ovako.com

10. Material Development Why Air-Hardening Steels? • Reduce distortion of heat treated components after quenching • Minimize the number of production steps • Additionally the use of quenching medias such as oil and salt can be avoided, which improves both safety and environment http://www.rfglonline.com Reduce the total cost of production

11. Material Development Experimental tests on new air-hardening steels Preliminary testing campaign have been performed for characterising the novel air-hardening steels: • Rotating Bending Fatigue (RBF) tests • Contact Fatigue (CF) tests

12. Material Development Ultra-Dispersed Diamond Powders (UDDP) • Ultra-Dispersed Diamond Powders (UDDP) are synthetic diamonds obtained with the use of explosion energy (Controlled Detonation Synthesis - CDS) • Enhanced properties expected by the use of UDDP on gears are: • wear resistance • micro - hardness • corrosion resistance

13. Novel Surface Treatments • Novel surface treatments and coatings have been analysed for the improvement of friction/lubrication aspects and wear gear resistance Ni + UDDP

14. Novel Surface TreatmentsThermal Spraying Processes • Two Thermal Spraying Processes have been used for testing several coatings (WC + Co, Mo, etc.): • HVOF (High Velocity Oxygen Fuel) • Detonation Spraying Technique Mo Coating HVOF Process

15. Novel Surface TreatmentsPVD Processes • Two Physical Vapour Deposition (PVD) processes have been usedfor testing several coatings (TiCrC, TiN, TiCrN, etc.): • Arc Vapour Deposition • Magnetron Sputtering PVD Magnetron Sputtering

16. Novel Surface TreatmentsSurface Finish Enhancement Process • C.A.S.E.sm(Chemically Assisted Surface Engineering) process consists of a combination of shot peening followed by isotropic finishing • The isotropic finishing removes the asperities left from shot peening via vibratory polishing techniques while maintaining the integrity of the residual compressive layer • Tests perform on gears made of OVATEC 277 and OVATEC 677 in superfinished conditions have shown an increase of bending fatigue strength of 48% and 71% respectively compared to hobbed conditions

17. Novel Gear Design and Manufacturing • Design strategies based on conventional manufacturing methods – do not include any operations that are not currently used in wind turbine industries • Improved efficiency to 99.612% achieved following standard gear design practises – no additional costs associated with manufacture of low loss gear designs proposed in X-GEAR Project 120µm tip relief, 10µm crowning (efficiency = 99.612%) 80µm tip relief, 10µm crowning (efficiency = 99.557%)

18. Testing of Novel Wind Turbine Gears Test Rigs (Wind Energy Demonstrators) Bending Fatigue Test Rig

19. Development of Design Tool http://www.x-gear.org • Home • Public Documents • Project Documents • WP Description • X-gear Tools

20. Development of Design ToolX-GEAR Material Database

21. Development of Design ToolX-GEAR E-Learning Tool

22. Development of Design ToolX-GEAR Design Tool

23. X-Gear Approach The innovative approach of X-Gear project is to combine novel materials, novel surface treatments, novel manufacturing processanddesign in order to develop a new generation of gears for wind turbine applications New Materials Novel Surface Treatments & Coatings Design Software Tool

24. Contacts D’Appolonia S.p.A. Via S. Nazaro, 19 16145 Genova Tel. (+39) 010 3628148 Fax. (+39) 010 3621078 X-Gear website: www.x-gear.org E-mail: alessandro.bozzolo@dappolonia.it

25. Thank you for your attention