A novel method for the evaluation of the contamination dispersing ability of lubricants (CONTA-DISP)

Water and solid particulate contamination are the two most common contaminants of lubricated systems and may be highly problematic for these systems. To reduce downtime and prevent failure, lubricant formulations contain detergent and dispersant additives that play an important role in terms of contamination tolerance. In lack of a practical procedure for the determination of the relevant properties, a novel method for the evaluation of the dispersing ability of lubricating oils is introduced. Following and combining established lubricant analysis methods, a procedure with optimum parameters was found. An assessment of the method using fresh and artificially altered lubricating oils allowed a differentiation concerning their dispersing ability.

Investigation of the Tribological Behavior of Mineral Lubricant Using Copper Oxide Nano Additives

In this study, tribological properties of custom formulated and stabilized nano lubricant are investigated. Spherical CuO nanoparticles are suspended in 20W-50 mineral base lubricant using Oleic Acid (OA) as a surfactant. Three different nano lubricant concentrations with 0.2, 0.5, and 1 wt.% were analyzed through ASTM G-99 pin-on-disc tribometer standardized test under boundary/mixed lubrication regimes. The generated friction and wear analyses confirm a consolidation of tribological properties with a reduction in friction coefficient in the range of 14.59–42.92%, compared with the base lubricant. Analysis of worn surfaces (SEM/EDX) as well as (AFM) was conducted. Combined hypotheses were proposed from the analysis of worn surfaces; these hypotheses suggested that CuO nanoparticles exhibit an integrated effect of two phenomenal lubrication mechanisms. Additionally, dispersion stability evaluation of the suspended nanoparticles was performed through Zeta potential, (FTIR), and sedimentation analyses. Stability results showed that steric stabilization is the dominating effect of the repulsive forces between nanoparticles, surpassing the electrostatic repulsive forces.

Lubricant Analysis as the Most Useful Tool in the Proactive Maintenance Philosophies of Machinery and its Components

Condition monitoring and fault diagnosis of engineering systems are critical for the stable and reliable operation in various areas as mobile technology (primarily agricultural, forestry, mining and construction machinery), railways, airlines and large fleets. Thus, to achieve a satisfactory level of reliability for the life of a machine, proactive maintenance strategy is the only key. This means that the application of classical reliability methods suitable for components with sudden failures can be complemented by technical diagnostic methods which have the potential to provide the information about the system condition. In this article we focus on the diagnostic signal related to the used oil – tribodiagnostic measures and is an interesting theoretical item related to the evaluation of the quality of lubricants in the aspect of operation. This is because the oil is in direct contact with single parts of the assessed technical systems. Results tests were reviewed and derived from various parameters of lubricants and their limits that highlight the condition and state of the lubricants under varying categories which include, physiochemical, elemental (wear), contamination and additive analysis.

Tribological Investigation on the Friction and Wear Behaviors of Biogenic Lubricating Greases in Steel–Steel Contact

The applications of biogenic lubricating greases to machine elements play important roles in the reduction of friction energy and minimizing wear in a tribological contact, as well as the prevention of environmental pollution. The aim of this work was to investigate completely biogenic lubricating greases from a tribological point of view. Model greases were examined using a ball on a disc tribometer at a constant normal force to investigate the friction and wear process according to Fleischer’s energetic wear model. Using the energy-based wear model, the friction and wear process could be interpreted as a cause–effect sequence. Moreover, the influence of the model grease composition on the friction and wear process was analyzed. In addition, rolling bearing tests were performed to investigate the tribological behaviors of some selected biogenic greases during real machine element contact. These tests allowed for the quantification of the friction torque behavior of the full bearing and the evaluation of the wear obtained through lubricant analysis procedures. This experimental work provides useful information regarding the influence that the composition of biogenic model greases has on friction and wear behaviors in a tribological contact.

Decision Making in the Choice of Condition-Based Maintenance Techniques in a Subsidiary of a Petrochemical Company

Condition-based maintenance (CBM) may be considered an essential part of the Industry 4.0 environment because it can improve production processes through the use of the latest digital technologies, which allows improvements to products, processes, and business models. Nonetheless, despite this importance, there are no models or methodologies in the literature to assist in choosing predictive techniques and the level of complexity to be used in a given organization. This chapter describes a model for choosing the most suitable CBM technique to be introduced in a subsidiary of a petrochemical plant. The predictive techniques of vibration analysis, lubricant analysis, and a combination of the two were considered at three technological levels. The model was built using the measuring attractiveness by a categorical based evaluation technique (MACBETH) approach. The present model could avoid failures in these programmes when making decisions about the techniques and technologies most suited to the characteristics of the industrial plant.

Control of Activity of Aircraft Engines by Analysis of Wear Debris Particles in Terms of Shape and Size

The contribution deals with use of semi-automated method of magnetic separation of particles in order to control mechanical system of aircraft engines. There are three levels of machine wear characterized by means of wear debris particle analysis in the lubrication system of aircraft engines. The shape and size of wear debris particles formed due to machine wear arise immediately in case of wear change thus this method is extremely suitable to control mechanical system washed by lubricant. Analysis of actual samples of lubricating oils containing several types of wear debris at the same time resulted in finding out and characterizing the levels of wear, from standard up to critical one. The contribution describes typical types of aircraft engine lubrication system wear with allocation of the wear level to particular pictures of wear debris particles.