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Comparative Friction Assessment of Different Valve-Train Types Using the FLARE (Friction and Lubrication Analysis) Code
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Abstract
A mathematical model for tribological analysis of different automotive- valve-train configurations has been developed as a part of the FLARE (Friction and Lubrication Analysis of Reciprocating Engines) package. The model is based on an in-depth kinematic analysis and on a rigid-body dynamic analysis, including dynamic analysis of the valve spring. Lubricant film thickness, contact pressures, and frictional power loss are predicted. A mixed-lubrication model is used to determine the friction force at the cam-follower interface. In addition, lifter rotation is modeled to predict its effect on frictional power loss. Detailed results are presented for a pushrod valve train. Also, this paper compares frictional power loss for five different valve train types. They are: direct-acting overhead cam, pushrod, end-pivoted finger follower, center-pivoted finger follower, and cam-in-head. The valve trains are made equivalent by keeping the valve lift and the no-follow speed the same. In addition, all other valve train parameters were kept the same with a few exceptions. From this study, it appears that the direct acting valve train has the lowest frictional power loss. The two finger follower valve trains viz., the end-pivoted and the center-pivoted are among those with the highest power loss. The system features of FLARE make a comparative study such as the one presented here very convenient.
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Citation
Paranjpe, R. and Gecim, B., "Comparative Friction Assessment of Different Valve-Train Types Using the FLARE (Friction and Lubrication Analysis) Code," SAE Technical Paper 920491, 1992, https://doi.org/10.4271/920491.Also In
References
- Rosenberg, R. C “General Friction Considerations For Engine Design,” SAE Paper 821576 1982
- Goenka, P. K. Paranjpe, R. S. Jeng, Y.-R. “FLARE: An Integrated Package for Friction and Lubrication Analysis of Automotive Engines. Part I: Overview and Application,” SAE Paper 920487 1992
- Armstrong, W. B. Buuck, B.,A. “Valve Gear Energy Consumption Effect of Design and Operation Parameters,” SAE Paper 810787 1981
- Paranjpe, R. S. “Dynamic Analysis of a Valve Spring With a Coulomb-Friction Damper,” ASME Journal of Mechanical Design 112 December 1990 509 513
- Gecim, B. “Tribological Study For a Low-Friction Cam/Tappet System Including Tappet Spin,” Annual Meeting of Society of Tribologists and Lubrication Engineers April 29 1991 Montreal, Canada Tribology Transactions
- Greenwood, J. A. Tripp, J. H. “The Contact of Two Nominally Flat Rough Surfaces,” Proc. Instn. Mech. Engrs. 185 48 71 1970 1971 625 633
- Bair, S. Griffioen, J. A. Winer, W. O. “The Tribological Behavior of an Automotive Cam and Flat Lifter System,” ASME Transactions Journal of Tribology 108 1986 478 486
- Pieprzak, J. M. Willermet, P. A. Klassen, D. “A Tappet Rotation Monitor Based on Light Reflectance - Development and Functional Testing,” SAE Paper 890722 1989
- Paranjpe, R. S. Cusenza, A. “FLARE: An Integrated Package for Friction and Lubrication Analysis of Automotive Engines. Part II: Experimental Validation,” SAE Paper 920488 1992