• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.8
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• pp.1608-1614
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• 2002

This Paper presents a novel piston friction force measurement system that has characteristics of relieving the Pressure force acting on the upper surface of the liner; the system uses general rubber O-rings for combustion chamber sealing, and does not need special changes to the piston top land. The lower supporter of the floating liner increases stiffness in liner axial direction, and results in the increase of natural frequency. The upper supporter has multi-layer structure designed fer low axial stiffness and high radial stiffness. With the use of the present system, the effects of variation in clearance and piston ring tension were studied.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.349-356
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• 2003

The aim of this paper is to investigate the friction characteristics of piston assembly. The friction of piston assembly is composed of ring pack and skirt friction. In this paper, the theoretical models of piston ring pack and piston skirt were presented. The mixed lubrication theory was considered to calculate friction force of piston ring and skirt. from the results, most of friction in piston assembly occurred at the piston ring park. The piston assembly usually showed hydrodynamic lubrication characteristics. but the top and bottom dead centers showed mixed lubrication characteristics. The piston skirt was much affected by radial clearance and load, but ring was significantly influenced by ring tension.