Cross hatched texture influence on the load carrying capacity of oil control rings

• The cross-hatched texture provides a load carrying capacity to a flat oil control ring.
• This load carrying capacity is a function of the operating conditions and the cross-hatched texture geometry (groove depth, width…).
• A simplified 1D analytical model predicts the existence of an optimum groove geometry (regarding the dimensionless load carrying capacity).
• This analytical model also allows one to predict the influence of the groove density.
• A set of 2D numerical results is presented; the groove angle and depth influence are included in the curve-fitting equations.

The optimization of the cylinder-liner/piston-ring contact performance (oil consumption, friction and wear) is the final objective of this work. The micro-geometry impacts directly the contact behavior. Cross-hatched textures are usually manufactured on cylinder liner surfaces. Grooves are often described as lubricant reservoirs and pipes redistributing oil. Grooves also change the pressure distribution and load carrying capacity.The top ring generally has a parabolic shape. Oil control rings on the contrary are usually flat. Thus, the contact between an oil control ring and a smooth cylinder liner has no load carrying capacity. Cross hatched textures enable a certain load carrying capacity which depends on the operating conditions and the texture micro-geometry. This paper presents a numerical and an analytical analysis of this phenomenon. A set of functional parameters is proposed to model this contact and predict its load carrying capacity.