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Friction Measurement in the Valve Train with a Roller Follower
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English
Abstract
The valve train was instrumented to record the instantaneous roller speed, roller pin friction torque, pushrod forces, and cam speed. Results are presented for one exhaust valve of a motored Cummins L-10 engine. The instantaneous cam/roller friction force was determined from the instantaneous roller speed and the pin friction torque. The pushrod force and displacement were also measured. Friction work loss was determined for both cam and roller interface as well as the upper valve train which includes the valve pushrod, rocker arm, valve guide, and valve. Roller follower slippage on the cam was also determined. A kinematic analysis with the measured data provided the normal force and contact stress at cam/roller interface.(1) Finally, the valve train friction was found to be in the mixed lubrication regime.(2)
Further efforts will address the theoretical analysis of valve train friction to predict roller slippage.
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Citation
Lee, J., Patterson, D., Morrison, K., and Schwartz, G., "Friction Measurement in the Valve Train with a Roller Follower," SAE Technical Paper 940589, 1994, https://doi.org/10.4271/940589.Also In
References
- Lee, J. “Dynamic modeling and experimental verification of a valve train including lubrication and friction,” Department of Mechanical Engineering, The University of Michigan 1993
- Gecim, B.A. “Tribological study for a low-friction cam/tappet system including tappet spin,” STLE Transactions 35 225 234 1992
- Staron, J.T. Willermet, P.A. “An analysis of valve train in terms of lubrication principles,” SAE paper No. 830165
- Sun, D.C. Rosenberg, R.C. “An experimental study of automotive cam-lifter interface friction,” ASLE Transactions 30 167 176 1986
- Paranjpe, R.S. Gecim, B.A. “Comparative friction assessment of different valve train types using the FLARE code,” SAE paper No. 920491