The effect of square-shaped pockets position in sliding line contacts under mixed regime of lubrication

The production of surface topography by artificial pockets is introduced as a well-known method to reduce friction and wear between conjugating surfaces under different lubrication regimes. As a result, the proper design and position of the pockets are of prime importance. This paper supports that goal and focuses on the contribution of the square-shaped textures in several inlet positions and densities on film thickness and wear of line contacts under mixed lubricated conditions. The applied load, the sliding speed, and the lubricant oil are set on a custom-built block-on-ring test rig. The lubricant film thickness is measured in real time using capacitive sensors. The wear behavior of the pocketed samples is also examined by an optical microscopy before and after the tests. The findings are compared by the results of similar studies. The results showed that using square-shaped pockets with high density in line contacts can pronounce film thickness up to 40% than the sparser pattern, which resulted in lowest level of abrasive wear. The position of the square-shaped pockets comprising the inlet lubricant flow is given a beneficial effect on starvation in line contacts, helping to lubricant replenishment into the contact.

[1]  Pantelis G. Nikolakopoulos,et al.  Evolutionary Optimization of Micro- Thrust Bearings With Periodic Partial Trapezoidal Surface Texturing , 2011 .

[2]  R.A.J. Ford,et al.  Laser-based fluorescence techniques for measuring thin liquid films , 1978 .

[3]  Michael M. Khonsari,et al.  An Experimental Investigation of Dimple Effect on the Stribeck Curve of Journal Bearings , 2007 .

[4]  Martin Hartl,et al.  Effect of Surface Texturing on Very Thin Film EHD Lubricated Contacts , 2008 .

[5]  J. Greenwood,et al.  The Contact of Two Nominally Flat Rough Surfaces , 1970 .

[6]  Pantelis G. Nikolakopoulos,et al.  Simulation of piston ring tribology with surface texturing for internal combustion engines , 2015 .

[7]  Yoshiteru Yasuda,et al.  Effect of surface texturing on friction reduction between ceramic and steel materials under lubricated sliding contact , 2003 .

[8]  Izhak Etsion,et al.  Analytical and Experimental Investigation of Laser-Textured Mechanical Seal Faces , 1999 .

[9]  P S Dellis.  Effect of friction force between piston rings and liner: A parametric study of speed, load, temperature, piston-ring curvature, and high-temperature, high-shear viscosity , 2010 .

[10]  M. Efzan,et al.  Effect of EDM dimple geometry on friction reduction under boundary and mixed lubrication , 2016 .

[11]  K. Johnson.  Contact Mechanics: Frontmatter , 1985 .

[12]  Andreas A. Polycarpou,et al.  Friction characteristics of microtextured surfaces under mixed and hydrodynamic lubrication , 2013 .

[13]  A. Olver,et al.  The Transient Friction Response of a Laser-Textured, Reciprocating Contact to the Entrainment of Individual Pockets , 2016, Tribology Letters.

[14]  Antonius Lubrecht,et al.  Cross hatched texture influence on the load carrying capacity of oil control rings , 2015 .

[15]  Jaal Ghandhi,et al.  Design of Capacitance Probes for Oil Film Thickness Measurements Between the Piston Ring and Linear in Internal Combustion Engines , 2001 .

[16]  I. Etsion.  State of the art in Laser Surface Texturing , 2004 .

[17]  Roberto F. Ausas,et al.  Moving textures: Simulation of a ring sliding on a textured liner , 2014 .

[18]  M. Fillon,et al.  Analytical investigation of a partially textured parallel slider , 2009 .

[19]  Michael M. Khonsari,et al.  Experimental investigation of tribological performance of laser textured stainless steel rings , 2011 .

[20]  H Rahnejat,et al.  Combined numerical and experimental investigation of the micro-hydrodynamics of chevron-based textured patterns influencing conjunctional friction of sliding contacts , 2015 .

[21]  Izhak Etsion,et al.  Experimental Investigation of Laser Surface Textured Parallel Thrust Bearings , 2004 .

[22]  I Sherrington.  Oil film thickness measurement: a contribution to the understanding and control of lubrication in the piston-ring packs of IC engines , 2011 .

[23]  Homer Rahnejat,et al.  A hydrodynamic flow analysis for optimal positioning of surface textures , 2017 .

[24]  M. Khonsari,et al.  The effect of laser machined pockets on the lubrication of piston ring prototypes , 2016 .

[25]  Pantelis G. Nikolakopoulos,et al.  Cavitation effects on textured compression rings in mixed lubrication , 2016 .

[26]  Eduardo Tomanik,et al.  Modelling the hydrodynamic support of cylinder bore and piston rings with laser textured surfaces , 2013 .

[27]  Ian Graham Pegg,et al.  Lubricant film thickness and friction force measurements in a laser surface textured reciprocating line contact simulating the piston ring – liner pairing , 2016 .

[28]  G. Shirong,et al.  Tribological properties of surface dimple-textured by pellet-pressing , 2009 .

[29]  Homer Rahnejat,et al.  A combined analytical‐experimental investigation of friction in cylinder liner inserts under mixed and boundary regimes of lubrication , 2017 .

[30]  Pawel Pawlus,et al.  Improving tribological behaviour of piston ring–cylinder liner frictional pair by liner surface texturing , 2013 .

[31]  Andreas Almqvist,et al.  A mixed lubrication model incorporating measured surface topography. Part 2: Roughness treatment, model validation, and simulation , 2010 .

[32]  Dimitrios A. Bompos,et al.  Experimental Measurements of Journal Bearing Friction Using Mineral, Synthetic, and Bio-Based Lubricants , 2015 .

[33]  Ian Sherrington,et al.  Experimental methods for measuring the oil-film thickness between the piston-rings and cylinder-wall of internal combustion engines , 1985 .

[34]  A. Olver,et al.  Combined friction and wear reduction in a reciprocating contact through laser surface texturing , 2016 .

[35]  Rob Dwyer-Joyce,et al.  Piezoelectric sensors to monitor lubricant film thickness at piston–cylinder contacts in a fired engine , 2013 .

[36]  I. Etsion,et al.  Testing piston rings with partial laser surface texturing for friction reduction , 2006 .

[37]  J. A. Walowit,et al.  A Theory of Lubrication by Microirregularities , 1966 .

[38]  Kenneth Holmberg,et al.  Global energy consumption due to friction in passenger cars , 2012 .

[39]  Yonggang Meng,et al.  Experimental investigation on effects of surface texturing on lubrication of initial line contacts , 2014 .

[40]  A. Gangopadhyay,et al.  Looking into a laser textured piston ring-liner contact , 2017 .

[41]  Y. Chiu.  An Analysis and Prediction of Lubricant Film Starvation in Rolling Contact Systems , 1974 .

[42]  Homer Rahnejat,et al.  Optimisation of the piston compression ring for improved energy efficiency of high performance race engines , 2017 .

[43]  Staffan Jacobson,et al.  Influence of surface texture on boundary lubricated sliding contacts , 2003 .

[44]  Homer Rahnejat,et al.  Integrated Tribological Analysis within a Multi- physics Approach to System Dynamics , 2005 .

[45]  Pawel Pawlus,et al.  Abrasive wear resistance of textured steel rings , 2009 .

[46]  Rob Dwyer-Joyce,et al.  Ultrasonic Imaging of the Piston Ring Oil Film During Operation in a Motored Engine - Towards Oil Film Thickness Measurement , 2010 .

[47]  I. Etsion,et al.  Improving Tribological Performance of Piston Rings by Partial Surface Texturing , 2005 .