The objectives of this investigation were to design and develop an experimental turbocharger test rig (TTR) to measure the shaft whirl of the rotating assembly and the axial and frictional loads experienced by the bearings. The TTR contains a ball bearing turbocharger (TC) that was instrumented and operated under various test conditions up to 55,000 …
The work presented in this paper describes a new approach to calculate the film profile, friction, and fluid transport of a reciprocating U-cup seal used in a hydraulic piston pump. An innovative partial lubrication model of the seal is developed, which connects the inverse hydrodynamic lubrication method and Greenwood–Williamson asperity contact model. Finite element models …
Finite element analysis is conducted on an elastic-plastic full stick contact between a rigid flat and a deformable coated sphere with a soft coating. A combined normal and tangential load is applied to the rigid flat, and the sliding inception is assumed as a result of the decreasing tangential stiffness of the contact junction. As …
Tribologists use the iconic image of Egyptians lubricating the logs used to move the large stones and stone carvings. To rival that — archaeologists studying Stonehenge discovered that these ancient people may have used pig lard to lubricate sleds used to move the massive stones. Tribologists may need to think about ancient practices more. Stonehenge_from_north,_August_2010.jpg …
Super duplex stainless steel (SDSS) has excellent mechanical properties and corrosion resistance. However, currently, there are few researches conducted on its fretting wear performance. This paper studies the influence of different heat treatment temperatures and medium environment on the fretting wear performance of SAF 2507 SDSS. Results show that the combined effect of the sigma …
Effects of shaft shape errors are studied on dynamic characteristics of a rotor-bearing system. Stability characteristics of the cylindrical journal bearing are studied. It is shown that the rotating speed at which the oil whip occurs increases when the shape errors exit. And, there is a threshold speed of the bearing with shaft shape errors; …
Hydrophobic and self-cleaning photocatalytic ceramics and concrete with potential for the superhydrophobicity are promising novel materials for civil engineering applications including buildings, bridges, road pavements, and airport runways. Due to embedded liquid-repellent properties, such materials have low water and salt absorption and, therefore, enhanced durability. However, in applications requiring high traction (e.g., tire and pavement), …
A nonlinear dynamic model is proposed to investigate the dynamic interactions between the rolling element and cage under rotational speed fluctuation conditions. Discontinuous Hertz contact between the rolling element and the cage and lubrication and interactions between rolling elements and raceways are considered. The dynamic model is verified by comparing simulation result with the published …
In this study, tribological characteristics of diethylene glycol dimethyl ether (DGM)/diethylene glycol dimethyl ether–diesel blend A (10 vol% DGM + 90 vol% diesel)/diesel were compared after being subjected to quill roller-ball friction and four-ball friction tests. The lubricity and antiwear property of blend A were worse than those of diesel, albeit considerably better than those …
Here’s the monthly summary of chemistry stories that have hit the news. This month features news on a way to convert A type blood to O type blood, how magnets can enhance hydrogen production from water, and more! Larger summary images for each item are provided below, along with links to articles and studies for …
