A finite element study of piston tilt effects on piston ring dynamics in internal combustion engines

The motion of the piston and rings strongly influences lubrication and blow-by in a reciprocating engine. Three-dimensional finite element models of single-cylinder and four-cylinder internal combustion (IC) engines are developed to analyse the piston and ring motions. The ring motion in the radial and axial directions and the ring twist, along with the end gap size variation, are studied in detail. Results are compared with those obtained by neglecting piston secondary motions. A comparative analysis of piston and ring motions between the single-cylinder and four-cylinder engines has also been performed. It has been found that the predicted ring motion of a single-cylinder engine is different from that of a multicylinder engine. The conclusion is that piston tilt has a profound effect on the end gap variation, the ring twist and the ring lift.