DJL

Tribology Transactions, Volume 57, Issue 5, Page 831-837, September-October 2014.

Tribology Transactions, Volume 57, Issue 5, Page 806-813, September-October 2014.

Publication date: 15 July 2013
Source:Wear, Volume 304, Issues 1–2
Author(s): Enzhu Hu , Xianguo Hu , Tianxia Liu , Ling Fang , Karl D. Dearn , Hongming Xu
This paper describes a study of the influence of soot contamination on the tribological behavior of engine lubricants. The candidate lubricants were a formulated engine lubricant, (CD SAE 15W-40) and a base oil (150SN). Soot particle contamination was simulated using carbon black with friction and wear measured using a four-ball tribometer. The results show that the antiwear and antifriction properties of the CD SAE 15W-40 formulated oil with varying carbon black contents were better than those of 150SN base oil. The antifriction properties of the SAE 15W‐40 formulated oil with the addition of 2wt% carbon black were strengthened. This was ascribed to uniformly dispersed carbon black and the additives in the CD SAE 15W-40. The antifriction properties of the 150SN base oil with 2, 4wt% carbon black content were upgraded via the addition of 2wt% dispersant polyisobutylene succinimide. The tribological effect of the carbon black in the lubricants was attributed to absorption and agglomerate effects.

Publication date: 1 September 1982
Source:Wear, Volume 80, Issue 3
Author(s): A.M. Stoneham , A.H. Harker

Publication date: 30 July 2013
Source:Wear, Volume 305, Issues 1–2
Author(s): Itto Sugimoto , Fumiaki Honda , Kenichi Inoue
Diamond-like carbon (DLC) with high hardness and low friction has been applied to automotive parts. In this study, the significant wear of hydrogenated DLCs under molybdenum dithio-carbonate (MoDTC)-containing oil was evaluated by a reciprocating sliding tester and the wear has been investigated. Analysis of wear debris collected from oil after a sliding test revealed that DLC wear under MoDTC-containing boundary lubrication are caused by the graphitization, same as in solid lubrication confirmed by previous reports. On the other hand, Mo compounds that are decomposition products of MoDTC harden the surface of counterparts and have the potential of accelerated wear.

Publication date: October 2014
Source:Tribology International, Volume 78
Author(s): Kenneth Holmberg , Peter Andersson , Nils-Olof Nylund , Kari Mäkelä , Ali Erdemir
In this paper, we report the global fuel energy consumption in heavy-duty road vehicles due to friction in engines, transmissions, tires, auxiliary equipment, and brakes. Four categories of vehicle, representing an average of the global fleet of heavy vehicles, were studied: single-unit trucks, truck and trailer combinations, city buses, and coaches. Friction losses in tribocontacts were estimated by drawing upon the literature on prevailing contact mechanics and lubrication mechanisms. Coefficients of friction in the tribocontacts were estimated based on available information in the literature for four cases: (1) the average vehicle in use today, (2) a vehicle with today׳s best commercial tribological technology, (3) a vehicle with today׳s most advanced technology based upon recent research and development, and (4) a vehicle with the best futuristic technology forecasted in the next 12 years. The following conclusions were reached: • In heavy duty vehicles, 33% of the fuel energy is used to overcome friction in the engine, transmission, tires, auxiliary equipment, and brakes. The parasitic frictional losses, with braking friction excluded, are 26% of the fuel energy. In total, 34% of the fuel energy is used to move the vehicle. • Worldwide, 180,000 million liters of fuel was used in 2012 to overcome friction in heavy duty vehicles. This equals 6.5millionTJ/a; hence, reduction in frictional losses can provide significant benefits in fuel economy. A reduction in friction results in a 2.5 times improvement in fuel economy, as exhaust and cooling losses are reduced as well. • Globally a single-unit truck uses on average 1500l of diesel fuel per year to overcome friction losses; a truck and trailer combination, 12,500l; a city bus, 12,700l; and a coach, 7100l. • By taking advantage of new technology for friction reduction in heavy duty vehicles, friction losses could be reduced by 14% in the short term (4 to 8 years) and by 37% in the long term (8 to 12 years). In the short term, this would annually equal worldwide savings of 105,000 million euros, 75,000 million liters of diesel fuel, and a CO2 emission reduction of 200 million tones. In the long term, the annual benefit would be 280,000 million euros, 200,000 million liters of fuel, and a CO2 emission reduction of 530 million tonnes. • Hybridization and electrification are expected to penetrate only certain niches of the heavy-duty vehicle sector. In the case of city buses and delivery trucks, hybridization can cut fuel consumption by 25% to 30%, but there is little to gain in the case of coaches and long-haul trucks. Downsizing the internal combustion engine and using recuperative braking energy can also reduce friction losses. • Electrification is best suited for city buses and delivery trucks. The energy used to overcome friction in electric vehicles is estimated to be less than half of that of conventional diesel vehicles. Potential new remedies to reduce friction in heavy duty vehicles include the use of advanced low-friction coatings and surface texturing technology on sliding, rolling, and reciprocating engine and transmission components, new low-viscosity and low-shear lubricants and additives, and new tire designs that reduce rolling friction.