A fully coupled tribo-dynamic model for piston-ring-liner system

As key friction pairs affecting the whole engine reliability, the piston-ring-liner system generates more than 45% of the whole engine friction loss. But so far, three-dimensional tribo-dynamic models considering its complex motions are very limited. This paper proposes a new method from the perspective of multi-flexible-body dy-namics to realize a fully coupled modeling of the system's deformation, dynamics, and lubrication characteris-tics. The study considers the ring-groove contact characteristics and calculates the system boundary loads through the blow-by model. The effect mechanism of ring groove deformation on ring properties is revealed, and the system's complex tribo-dynamic behaviors such as twisting and fluttering are characterized. After fully coupled modeling, piston deformation at the ring groove position can be 65.80 mu m, resulting in a 1.33 mu m reduction in the minimum oil film thickness compared to the uncoupled model, and ring wear unevenness is aggravated.

Automated summary

This paper proposes a new method to achieve fully coupled modeling of the piston-ring-liner system from the perspective of multi-flexible-body dynamics. The study considers the contact characteristics of the ring groove and calculates the system boundary loads through the blow-by model. The effect of ring groove deformation on ring properties is revealed, and the complex tribo-dynamic behaviors of the system such as twisting and fluttering are characterized. After fully coupled modeling, piston deformation at the ring groove position can reach 65.80 μm, resulting in a 1.33 μm reduction in the minimum oil film thickness compared to the uncoupled model, and uneven ring wear is aggravated.