Öz
Cams are specially designed elements to convert rotational motion into translational or oscillatory motion through the follower. The movement that this rotational movement transfers to the mechanical components via the follower requires perfect timing. For this reason, wear that may occur on the cam surfaces will disrupt this perfect timing. The contact of the cam and follower surfaces should be prevented with an oil film. Since the contact surfaces are incompatible, elastohydrodynamic lubrication, a special form of hydrodynamic lubrication, occurs here. Under elastohydrodynamic lubrication (EHL) conditions (under heavy load, contact between incompatible surfaces), oil film formation is possible due to elastic deformations and the growth of viscosity with increasing pressure. Various numerical analysis methods have been developed to calculate the oil film thickness between two such surfaces. The theoretical basis of these methods is based on the joint solution of the Reynolds differential equation, viscosity-pressure equation and elastic deformation equations. In this study, the elastohydrodynamic oil film thickness formed between the cam and the follower surface was tried to be calculated with the help of the Hamrock-Dowson approach.
Anahtar Kelimeler
Kaynakça
- Bell vd., (1985). “Prediction of Automotive Valve Train Wear Patterns with Simple Mathematical Models”, Proceedings of the 12 th Leeds-Lyon Symposium on Tribology, Lyon, France.
- Cameron, A., (1966), The Principles of Lubrication, Cambridge University Press, Cambridge, U.K.
- Chen , F.Y., (1982). A text Book on Mechanics and Design of Cam Mechanisms, Pergamon Press.
- Dyson, A., (1980). “Kinematics and Wear Patterns of Cam and Finger Follower Valve Gear, Tribol. Int., 121-131.
- Dickrell III vd.,(2003). “The Evolution of Geometry for a Wearing Circular cam:Analytical and Computer Simulation With Comparison to Experiment”, Journal of Tribology, 125:187-192
- Fries, R.H. ve Rogers, C.A., (1988). “Predictions of Cam Wear Profiles”, Proceedings of the 15 th Leeds-Lyon Symposium on Tribology, 6-9 September 1988, Leeds Gecim, B.A.,”Lubrication and Fatigue Analysis of a Cam and Roller Follower”, Proceedings of the 15 th Leeds-Lyon Symposium on Tribology, 6-9 September 1988, Leeds:91-100
- Glovnea, R.P. ve Spikes, H.A., (2001). “The Influence of Cam Follower Motion on Elastohydrodynamic Film Thickness, in: Tribology Research:From Model Experiment to Industrial Problem”Elsevier, 485-493.
- Hamrock, B.J. ; Schmid, S.R. ; Jacobson, B.O. (2006) Fundamentals of Machine Elements, McGraw-Hill, International Edition, Singapore.
- Hamrock, B.J. (1994) Fundamentals of Fluid Film Lubrication, McGraw-Hill, New York.
- Keskin, İ. (2012). Yürek Mekanizmalarında Aşınma ve Elastohidrodinamik Yağlama. Doktora Tezi, Yıldız Teknik Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul.
- Lacobson, B. O.,(1991). Rheology and Elastohydrodynamic Lubrication, Tribology Series, 19, Elsevier Science Publishing Company, U.S.A.
- Purmer, P.D., ve Berg, W., (1985), “Measurement of Camshaft Wear-Wear and Kinematics of Overhead Camshafts, SAE, 850442:232-241.
- Rothbart, H.R., (2003). Cam Design Handbook, McGraw-Hill, New York.
- Shigley, J.E. ve Uicker, J.J.,(1995),. “Theory of Machines and mechanisms”, McGraw-Hill
- Soejima,M., vd., (1994).“Experimental Studies on Friction and Wear of Cam and Tappet”,JSAE Review,23:140-146.
- Soejima, M., Wakuri, Y. ve Ejima, Y., (1997). “Experimental Studies on Improvement of Lubrication for Cam and Follower”, JSAE Review, 18:301-305.
- Waldron, K.J. ve Kinzel, G.L., (2004). Kinematics, Dynamics and Design of Machinery, John Wiley & Sons, New York.
Öz
Kamlar, dönme hareketini, izleyici vasıtasıyla öteleme ya da salınım hareketine dönüştürmek amacıyla özel olarak dizayn edilen elemanlardır. Bu dönme hareketinin izleyici vasıtasıyla mekanik bileşenlere aktardığı hareket kusursuz bir zamanlama gerektirmektedir. Bu nedenle kam yüzeylerinde oluşabilecek aşınma, bu kusursuz zamanlamayı bozacaktır. Kam ve izleyici yüzeylerinin teması,yağ filmi ile engellenmelidir. Temas yüzeylerinin uyumsuz olması nedeniyle burada hidrodinamik yağlamanın özel bir formu olan elastohidrodinamik yağlama durumu ortaya çıkmaktadır. Elastohidrodinamik yağlama (EHL) koşullarında (ağır yük altında, uyumsuz yüzeyler arasındaki değme) yağ filmi oluşumu, elastik deformasyonlar ve viskozitenin artan basınçla büyümesi sayesinde mümkün olabilmektedir. Böyle iki yüzey arasındaki yağ filmi kalınlığını hesaplamak için çeşitli nümerik analiz yöntemleri geliştirilmiştir. Bu yöntemlerin teorik temeli Reynolds diferansiyel denklemi, viskozite-basınç denklemi ve elastik deformasyon denklemlerinin müşterek çözümüne dayanmaktadır. Bu çalışmada kam ve izleyici yüzeyi arasında oluşan elastohidrodinamik yağ filmi kalınlığı, Hamrock- Dowson yaklaşımı yardımıyla hesaplanmaya çalışılmıştır.
Anahtar Kelimeler
Kaynakça
- Bell vd., (1985). “Prediction of Automotive Valve Train Wear Patterns with Simple Mathematical Models”, Proceedings of the 12 th Leeds-Lyon Symposium on Tribology, Lyon, France.
- Cameron, A., (1966), The Principles of Lubrication, Cambridge University Press, Cambridge, U.K.
- Chen , F.Y., (1982). A text Book on Mechanics and Design of Cam Mechanisms, Pergamon Press.
- Dyson, A., (1980). “Kinematics and Wear Patterns of Cam and Finger Follower Valve Gear, Tribol. Int., 121-131.
- Dickrell III vd.,(2003). “The Evolution of Geometry for a Wearing Circular cam:Analytical and Computer Simulation With Comparison to Experiment”, Journal of Tribology, 125:187-192
- Fries, R.H. ve Rogers, C.A., (1988). “Predictions of Cam Wear Profiles”, Proceedings of the 15 th Leeds-Lyon Symposium on Tribology, 6-9 September 1988, Leeds Gecim, B.A.,”Lubrication and Fatigue Analysis of a Cam and Roller Follower”, Proceedings of the 15 th Leeds-Lyon Symposium on Tribology, 6-9 September 1988, Leeds:91-100
- Glovnea, R.P. ve Spikes, H.A., (2001). “The Influence of Cam Follower Motion on Elastohydrodynamic Film Thickness, in: Tribology Research:From Model Experiment to Industrial Problem”Elsevier, 485-493.
- Hamrock, B.J. ; Schmid, S.R. ; Jacobson, B.O. (2006) Fundamentals of Machine Elements, McGraw-Hill, International Edition, Singapore.
- Hamrock, B.J. (1994) Fundamentals of Fluid Film Lubrication, McGraw-Hill, New York.
- Keskin, İ. (2012). Yürek Mekanizmalarında Aşınma ve Elastohidrodinamik Yağlama. Doktora Tezi, Yıldız Teknik Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul.
- Lacobson, B. O.,(1991). Rheology and Elastohydrodynamic Lubrication, Tribology Series, 19, Elsevier Science Publishing Company, U.S.A.
- Purmer, P.D., ve Berg, W., (1985), “Measurement of Camshaft Wear-Wear and Kinematics of Overhead Camshafts, SAE, 850442:232-241.
- Rothbart, H.R., (2003). Cam Design Handbook, McGraw-Hill, New York.
- Shigley, J.E. ve Uicker, J.J.,(1995),. “Theory of Machines and mechanisms”, McGraw-Hill
- Soejima,M., vd., (1994).“Experimental Studies on Friction and Wear of Cam and Tappet”,JSAE Review,23:140-146.
- Soejima, M., Wakuri, Y. ve Ejima, Y., (1997). “Experimental Studies on Improvement of Lubrication for Cam and Follower”, JSAE Review, 18:301-305.
- Waldron, K.J. ve Kinzel, G.L., (2004). Kinematics, Dynamics and Design of Machinery, John Wiley & Sons, New York.
Ayrıntılar
| Birincil Dil | Türkçe |
|---|---|
| Konular | Triboloji |
| Bölüm | Araştırma Makaleleri |
| Yazarlar | |
| Yayımlanma Tarihi | 29 Aralık 2023 |
| Gönderilme Tarihi | 11 Aralık 2023 |
| Kabul Tarihi | 18 Aralık 2023 |
| Yayımlandığı Sayı | Yıl 2023 Cilt: 3 Sayı: 2 |
