Low-loss gears are an interesting design approach for increasing the efficiency and thermal load limits of gearboxes. The loss-optimized gear geometry concentrates sliding around pitch point, which results in low load-dependent power losses. In this study, a method modeling transient EHL (elastohydrodynamically lubricated) contacts mesh considering mixed lubrication effects is introduced applie...

In order to develop more efficient engines, it is essential to optimize the lubrication circuit of the power train systems. In this paper, during an engine design and development process, a network analysis of the engine lubrication system is described in detail. Two elements have been added to the lubrication circuit in the modified engine. These elements are hydraulic lifters and an Anti-drai...

The transition from boundary lubrication to fully hydrodynamic lubrication is investigated for air-lubricated slider bearings using the electrical resistance method. Intermittent contacts are shown to exist even under conditions for which the numerical solution of the Reynolds equation or white light interferometry predicts steady state spacings in the spacing region from 0.125 to 0.25 pm. The ...

In order to study the effect of surface roughness on lubrication performance an elastic support water-lubricated tilting pad thrust bearing, a mixed (ML) deterministic model is hereby presented based unified Reynolds equation model. This very incorporates elastic–plastic deformation asperities and polymer matrix pad, as well rubber support. The randomly distributed generated by mathematical sha...

In situ lateral force microscopy (LFM) and X-ray photoelectron spectroscopy (XPS) were used to probe the lubrication behavior of an aqueous solution of poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) (PEO-PPO-PEO) symmetric triblock copolymer on thin films of polypropylene (PP), polyethylene (PE), and cellulose. LFM experiments were carried out while the substrates were immersed in water...

In high speed rotating machines such as turbines and generators, vibrations of a rotating shaft often hinder the smooth operation of the machine or even cause failure. Oil whip is one of such vibrations due to oil film action of journal bearing. Its mechanism and preventive method is explained and proposed in this paper. Further theoretical and experimental analyses are made for considering hea...

Articular cartilage is a highly efficacious water-based tribological system that is optimized to provide low friction and wear protection at both low and high loads (pressures) and sliding velocities that must last over a lifetime. Although many different lubrication mechanisms have been proposed, it is becoming increasingly apparent that the tribological performance of cartilage cannot be attr...

Unidirectional sliding experiments with polished and laser textured steel surfaces were carried out to investigate the effects of different textured area densities, aspect ratios and dimple arrangements. The system was lubricated with Polyalphaolefin (PAO) at 100 °C and the contact pressure was 3 MPa. For measuring Stribeck curves, the sliding speed was controlled between 40 and 2000 mm/s. The ...