A Hydrodynamical Theory of Piston Ring Lubrication

Physics ◽  
1936 ◽  
Vol 7 (9) ◽  
pp. 364-367 ◽  
Author(s):  
R. A. Castleman
Keyword(s):  
Piston Ring ◽  
Piston Ring Lubrication ◽  
Hydrodynamical Theory

Analysis of Tribological Performance of Piston Ring Lubrication

2011 ◽  
Author(s):  
Yibin Guo ◽  
Wanyou Li ◽  
Dequan Zou ◽  
Xiqun Lu ◽  
Tao He
Keyword(s):  
Film Thickness ◽  
Friction Force ◽  
Power Loss ◽  
Piston Ring ◽  
Design Parameters ◽  
Oil Film ◽  
Starved Lubrication ◽  
Piston Ring Lubrication ◽  
Cylinder Bore ◽  
Lubrication Conditions

In this paper a mixed lubrication model considering lubricant supply conditions on cylinder bore has been developed for the piston ring lubrication. The numerical procedures of both fully flooded and starved lubrication were included in the model. The lubrication equations and boundary conditions at the end of strokes were discussed in detail. The effects of piston ring design parameters, such as ring face profile and ring tension, on oil film thickness, friction force and power loss under fully flooded and starved lubrication conditions due to available lubricant supply on cylinder bore were studied. The simulation results show that the oil available in the inlet region of the oil film is important to the piston ring friction power loss. With different ring face crown heights and tensions, the changes of oil film thickness and friction force were apparent under fully flooded lubrication, but almost no changes were found under starved lubrication except at the end of a stroke. In addition, the oil film thickness and friction force were affected evidently by the ring face profile offsets under both fully flooded and starved lubrication conditions, and the offset towards the combustion chamber made a large contribution to forming thicker oil film during the expansion stroke. So under different lubricant supply conditions on the cylinder bore, the ring profile and tension need to be adjusted to reduce the friction and power loss. Moreover, the effects of lubricant viscosity, surface composite roughness, and engine operating speed on friction force and power loss were also discussed.

A review of studies of piston ring lubrication

1993 ◽  
pp. 109-121 ◽  
Author(s):  
B.L. Ruddy ◽  
D. Dowson ◽  
P.N. Economou
Keyword(s):  
Piston Ring ◽  
Piston Ring Lubrication

A Three-Dimensional Analysis of Piston Ring Lubrication Part 1: Modelling

1995 ◽  
Vol 209 (1) ◽  
pp. 1-14 ◽  
Author(s):  
M-T Ma ◽  
E H Smith ◽  
I Sherrington
Keyword(s):  
Internal Combustion Engines ◽  
Piston Ring ◽  
Three Dimensional ◽  
Combustion Engines ◽  
Three Dimensional Model ◽  
Engine Design ◽  
Piston Ring Lubrication ◽  
Almost All ◽  
Theoretical Analyses ◽  
Lubrication Conditions

The study of piston ring lubrication in internal combustion engines has remained a very active area in tribology. Theoretical analyses have been developed by many researchers to predict the performance characteristics of piston rings, but almost all previous models established were based upon the assumption that ring/cylinder geometry was axisymmetric. This may not be adequate for modern-day engine design since it is well known that cylinder bores are not perfectly circular. They suffer radial distortions which arise for various reasons. In the current work, a three-dimensional model has been developed to account for the effects of bore out-of-roundness. In order to do this, the three-dimensional Reynolds equation was solved cyclically using the finite difference method in fully flooded lubrication conditions. In this part of the paper, the theoretical model is presented and the effect of bore shape on piston ring performance is examined with three proposed types of bore (circular, elliptical and four-lobe). The results have shown that piston ring performance is significantly dependent on the bore shape or bore out-of-roundness.

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