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A twin-land oil control ring (TLOCR) model is used to evaluate TLOCR friction and the results are compared to the experiment measurement in a single cylinder floating liner engine under motoring condition. The model is based on a correlation between the hydrodynamic pressure and film thickness, which is generated using a deterministic model. The well-known three-regime lubrication is predicted with the model for ring with different ring tensions under various engine running conditions. A good match is found for the model and experiment results.

The objective of this work was to develop an experimental system to support development and validation of a model for the lubrication of two-piece Twin-Land-Oil-Control-Rings (hereafter mentioned as TLOCR). To do so, a floating liner engine was modified by opening the head and crankcase. Additionally, only TLOCR was installed together with a piston that has 100 micron cold clearance to minimize the contribution of the skirt to total friction. Friction traces, FMEP trend, and repeatability have been examined to guarantee the reliability of the experiment results. Then, engine speed, liner temperature, ring tension, and land widths were changed in a wide range to ensure all three lubrication regimes were covered in the experiments.

This paper presents a model for the lubrication and friction between a twin land oil control ring and the liner within an engine cycle. This model is based on the deterministic method, which considers micro geometry of the liner finish and its effects on both hydrodynamic lubrication and asperity contact. In this particular application, the liner surface micro features are solely responsible for hydrodynamic pressure generation due to the flat face profile of a typical twin land oil control ring, contrasting to the traditional average model where ring surface macro geometry is most important in generating hydrodynamic pressure.

This paper discusses the influences of several cylinder liner honing surface geometrical features on the interaction between the piston twin land oil control ring (TLOCR) and the cylinder liner by using the deterministic hydrodynamic model [1] and the twin land oil control ring model [2]. Additionally, the key design parameters of the TLOCR, including ring tension and land axial width are studied. The results show significant effects of three liner honing surface features beyond height distribution, including plateau wavelength, groove density and honing angle in hydrodynamic pressure generation. The study in oil control ring design parameters reveals that both ring tension and land axial width have important influences on friction and oil consumption, and their competing effects are discussed subsequently.