Turbocharger Lubrication - Lubricant Behavior and Factors That Cause Turbocharger Failure / Turboşarj Yağlama - Yağlama Davranışı ve Turboşarj Arızasına Neden Olan Faktörler

Öz

This paper is a review of the turbocharger lubrication system and at the same time an attempt to point out and analyze the factors responsible for turbocharger wear, damage and failures. In particular, the conditions under which the lubricant works are presented, from its entrance up to its exit from the turbocharger bearing housing. Additionally, the consequences of failure to comply with the instructions for appropriate turbocharger operation, are provided by the various manufacturers. Water cooled turbochargers (for which engine coolant is used), contribute significantly to the reduction of lubricant temperature, in the critical zones of its operation. This is achieved by reducing, the danger of oil “coking” effect (charred oil residues) or its decomposition, because of high temperature occurring in these zones. Turbochargers shaft support development using semi-floating bush bearings, has a significant impact on turbocharger manufacturing cost, as well as on their operational features. Further benefit may be had, when ball bearings are used (usually angular contact bearings are used) for turbocharger shaft support as they provide: a) a reduction of the kinetic friction coefficient, b) reduction of turbocharger lag during turbocharger shaft acceleration from low to high speeds, and c) reduced sealing problems. Regarding the failures that occur in turbochargers, their majority - up to 50% - is caused by problematic lubrication. The rest of the failures are divided between causes related to human factors (such as misuse and inadequate maintenance of a turbocharged vehicle) and external factors such as foreign objects entering either the compressor or turbine housings. Özet: Bu çalışma turboşarj yağlamasının bir değerlendirmesi ve aynı zamanda turboşarj gömlek, hasar ve bozuklukları için olası afaktörleri analiz etmek ve ortaya çıkarmak için bir girişimdir. Özelde yağın çalışma koşulu altındaki yağın girişinden turboşarjın yuvasından çıkışına kadar olan durumlar sunulmuştur. Ek olarak turboşarj operasyonunun uygunluğu için olan talimatlar ile bağdaşması için bozukluğun sonuçları çeşitli üreticiler tarafından sağlanır. Su soğutmalı turbosarjlar (motor soğutması kullanılan) operasyonun kritik bölgesinde yağlama sıcaklığının azaltılmasına katkıda bulunur. Bu bölgelerde görülen yüksek sıcaklıktan dolayı bu azaltılarak, yağ ‘kok’lama etkisinin tehlikesi (yakılmış yağ atığı) ya da onun dağılması tarafından başarılır. Turboşarjların milleri onların operasyonel çehresinde olduğu kadar turbaşarjer imalat maliyetinde de hatrı sayılır bir etkiye sahiptir. Onların sağladığı gibi mil desteği için top rulmanları (genellikle açısal temaslı rulmanlar kullanılır) kullanıldığı zaman daha öteki yararlarına sahip olunabilir: a) kinetic sürtünme katsayısının bir azalması, b) turboşarjer mili düşükten yükseğe ivmelenirken turboşarj gecikmesinin azalması ve c) azalan kapatma problemleri. Turboşarjlarda ortaya çıkan bozukluklar, %50 ya kadar onların etkinliği problemik yağlamaya sebep olur. Bozukluğun geri kalanı insanla r(bir turboşajlı aracının istismar edilmiş ve yetersiz özellikleri gibi) ve dışsal faktörler (kompresöre ya da turbine giren yabancı nesneler) arasında dönüştürülür.

Anahtar Kelimeler

• automotive; turbocharger; bearings; lubrication; failures; / otomotiv, turboşarj rulmanlar, yağlama, bozukluk

Kaynakça

1. Romagnoli, A. and Martinez-Botas, R. Heat Transfer on a Turbocharger Under Constant Load Points. ASME Conference Proceedings 2009(48869): 163-174.
2. Geralis A. and Gasparakis, E. Turbochargers-Superchargers Lubrication, Material Failures, Failure Statistics, Diploma Thesis, Higher School of Pedagogical and Technological Education - Department of Mechanical Engineering Educators, Athens 2009.
3. Bell, C. Maximum Boost: Designing, Testing and installing Turbocharger Systems, Bentley Publishers, 1997 USA, pp 39-44.Herman Hiereth and Peter Prenninger, Charging the Internal Combustion Engine, Springer – Verlag, 2003 Wien, pp 196-200.
4. Hugh Maclnnes, Turbochargers, Editor & Publisher Bill Fisher, 1976 USA, pp 21-26, 74-76 &173.
5. EMEA Aftermarket Event. Turbo fundamentals, June 17, 2009.6.
6. Edgar J. Gunter and Wen Jeng Chen, Dynamic Analysis of a Turbocharger in Floating Bushing Bearings, ISCORMA-3, Cleveland, Ohio, 19-23 September 2005.
7. Hiereth, H. and Prenninger, P. Charging the Internal Combustion Engine, Springer – Verlag, Wien, pp 196-200, 2003.
8. http://www.superstreetonline.com/techarticles/130_0909_turbocharge_understanding_guide/photo_04.html

9. Chen, W. J. (2012). "Rotordynamics and bearing design of turbochargers." Mechanical Systems and Signal Processing 29(0): 77-89.
10. http://www.superstreetonline.com/techarticles/130_0909_turbocharge_understanding_guide/photo_03.html
11. http://www.turbogarrett.com/turbogarrett/tech_center/turbo_tech101.html?#t101_3
12. http://www.airpowersystems.com/wrx/aps_turbo.htm
13. http://www.rotomaster.us/index.php?p=section&sid=29
14. http://www.tdiblog.com/tdi-basics/turbo-failure-101-oil-contamination/
15. Garrett Engine Boosting Systems, Turbocharger Damage Analysis, Four Major Causes, pdf file.
16. http://www.workturbochargers.com/knowledge-base/turbo-failure-101.html
17. A R Lansdown, Lubrication and Lubricant Selection, A Practical Guide, Professional Engineering Publishing, 2004 UK, Third Edition, pp 6-8.
18. Mourlas Athanasios, Applications of Liquid Laboratory exercise, Lubrication on Bearings, Tribology Laboratory, June 2011.
19. San Andres, L. «Liquid Cavitation in fluid film bearings» Modern Lubrication Theory, Mechanical Engineer Department, Texas A&M University 2010, Notes 6, pp 2-4.
20. M J Braun and W M Hannon, 2010, Cavitation formation and modeling for fluid bearings: A review, Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, pp 839-863.
21. Gwidon W. Stachowiak, Andrew W. Batchelor, Engineering Tribology, Batterwothn - Heinemann, 2001 USA, Second Edition, pp 163.