Hafif ticari taşıtlarda maliyet azaltma lı ayna mahruti malzemesi iyileştirmesi

Otomotiv sanayiinde mühendislerin öncelikli amaçlarından biri maliyetleri düşürürken mamul kalitesi ve dayanımını koruyabilmektir. Bu çalışmada, hafif ticari taşıtların diferansiyel sistemlerinde kullanılan, ayna mahruti dişli çiftinde, imalat işlemleri değiştirilmeden, daha düşük maliyetli malzemelerin kullanılabilmesi amaçlanmıştır. Halihazırda kullanılan malzeme ve önerilen malzeme ile imal edilmiş dişli çiftlerinin sertleştirilebilirlik kabiliyetleri kıyaslanmıştır. Kullanılmakta olan ve önerilen malzemelerden imal edilmiş dişli çiftleri, dinamometrenin de yer aldığı deney düzeneklerinde hızlandırılmış yorulma deneyleri ile hafif ticari taşıtların diferansiyel sistemlerine montajı gerçekleştirilerek, ömür testleri uygulanmıştır. Sonuç olarak, önerilen malzemenin sertleştirilebilirlik kabiliyeti mevcut malzeme ile aynı çıkmasına ve önerilen malzeme ile imal edilmiş dişlilerin taşıt performans deneyleri önceki malzemeden daha iyi olmasına rağmen, taşıt testleri sonrasında incelenen yuvarlanmalı yatak bağlantılarındaki hasarlardan ötürü, önerilen malzemenin yapılacak konstrüktif düzenlemeler neticesi ve kesinleştirme amacı ile yeniden yapılacak olan taşıt testlerinin sonucu da değerlendirilerek, taşıtlarda kullanılabileceği sonucuna varılmıştır. Ayrıca dinamometrede gerçekleştirilen yorulma deneyi sonuçlarının gerçek taşıt testlerine tekabül eden sonuçlar vermediği de tespit edilmiştir

Cost reduction oriented hypoid gear material optimization in commercial vehicles

Engineers in automotive industrie are trying to provide the same level of quality and durability with more economic materials. In this study, the use of an alternative material was investigated for a crown wheel and pinion design used in differential gear systems of light commercial vehicles. Changing gear set material manufactured with both current and proposed material was a cost reduction step by keeping same manufacturing processes. Hardenability characteristics of the gear sets were compared. Accelerated fatigue tests were performed in rig test set up with dynamometer and gear sets manufactured with proposed materials were assembled to light commercial vehicles and durability tests were performed on real road conditions. It was seen that hardenability characteristics of current and proposed materials are so close. Gear sets manufactured with proposed material performed durability test were completed successfully. However, the differentials assembled to durability test vehicles were tear down and it was realised pinion head bearing and pinion tail bearing inner ring contact areas were damaged. Proposed materials usage will be approved after design modification and repeated durability tests. Additionally it is determined that the accelerated fatigue test results in dynamometer test rigs does not overlap with the road test results

PDF

___

1. Erdin M.E., Helisel Konik Dişli Çarklarda Gerilmelerin Sonlu Eleman Yöntemiyle İncelenmesi, Doktora Tezi, Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Ankara, 2010.
2. Fetvacı M.C., Determination of Effective Involute Parameter Limit in Generation Simulation of Gears Manufactured by Pinion-type Cutters, Journal of the Faculty of Engineering and Architecture of Gazi University, 31 (2), 449-455, 2016.
3. Güllü E., Yılmaz T.G., Investigation Of Surface Pressure And Elastic Deformation On External and Internal Spur Gear, Journal of the Faculty of Engineering and Architecture of Gazi University, 32 (2), 585-591, 2017.
4. Jonggyu J., Seungjin N., et.al, Mechanical behavior of ultrafine-grained high-Mn steels containing nanoscale oxides produced by powder technology, Materials and Design, 92, 73-78, 2016.
5. Behrens B.A., Doege E., et.al., Precision forging processes for high-duty automotive components, Journal of Materials Processing Technology, 185, 139– 146, 2007.
6. John B., Mathias, W., Comparison of slip-rolling behaviour between 20MnCr5 gear steel, 36NiCrMoV1- 5-7 hot working tool steel and 45SiCrMo6 spring steel, Wear, 328-329, 28-38 2015.
7. Lefevre J., Hayrynen, K. L., Austempered Materials for Powertrain Applications, Journal of Materials Engineering and Performance, 13, 1914-1922, 2013.
8. Jeitler B., Hinteregger C., Leitner H., New Gear Manufacturing Technologies in the Automotive Field of Transmissions, Axle Drives and Transfer Cases, Proceedings Of The Asme International Design Engineering Technical Conferences And Computers And Information In Engineering Conference, 7, 813- 822, 2007.
9. Sergio B., Fatigue resistance of steel and titanium PVD coated spur gears, International Journal of Fatigue, 29, 1893–1903, 2007.
10. Khorsand H., Habibi, S. M., et.al., Fatigue of sintered steels (Fe - 1.5 Mo - 3 Mn - 0.7 C), Materials and Structures / Materiaux et Constructions, 37, 335-341, 2004.
11. Kleiss R., Ferfecki F.J., 2012, Designing A Polymer Gear For Use In The Environment Of An Internal Combustion Engine, Proceedıngs Of The Asme International Design Engineerıng Technıcal Conferences And Computers And Information In Engineering Conference, 8, 515-521, 2011.
12. Kapelevich A.L., Ananiev V.M., Gear Transmission Density Maximization, Proceedings Of The Asme International Design Engineering Technical Conferences And Computers And Information In Engineering Conference, 8, 127-133, 2012.
13. Eryürek İ.B., Hasar Analizi Ders Notları, 56 – 83, İTÜ, İstanbul, 1993.
14. Danilevsky J., Dişliler ve Dişli İmalatı, İmalat Mühendisliği, TMMOB Makine Mühendisleri Odası, 327 – 358, 1987.
15. Brown J., Advanced Machining Technology Handbook, Fineblanking, 33-44, 1998.
16. Chien W.Y., Pan J., Close D., Ho S., Fatigue Analysis of Crankshaft Sections Under Bending with Consideration of Residual Stresses, International Journal of Fatigue, 27, 1-19, 2005.
17. Shigley J.E., Mechanical engineering design, McGraw Hill, New York, U.S.A., 1986.
18. Çakır Y.A., Baykara C., Yenilmez A., Fetvacı C., Makina Elemanları Ders Notları, 1999.
19. Weibull, W., Fatigue Testing and Analysis of Results, 16-17, Pergamon Press, Sweden, 1961.