Browse Topic: Synthetic lubricants
This study investigates the particle engine emission characteristics including particle-bound metals for different lubricants used in a direct injection (DI) engine fed with the hydrogen-rich reformate containing 75% mol. H2 and 25% mol. CO2. The particle number concentration, size distribution and content of trace metals in the emitted particles are measured, analyzed, and compared for the baseline gasoline-fed engine and the reformate-fed engine. The results show that for all tested lubricants the particle number and mass emission from the reformate-fueled engine are significantly higher than from the baseline gasoline-fed counterpart. Also, an ICP analysis performed on PM demonstrated that the content of trace elements from the lubricant are higher for the reformate fuel. This indicates that an excessive lubricant involvement in combustion is the reason of these findings. Furthermore, the particle measurement results suggest that the engine using synthetic lubricant shows lower total particle number concentration and metal content in PM than it does with the mineral counterpart. However, particle number and mass distribution show more particles in the accumulation mode for the synthetic lubricant compared to the mineral one. The trace metals analysis shows that additives such as Ca, Na, P, Si, and Zn, present in relatively high amounts in the particle matter for each investigated lubricant. Si with its high boiling temperature clearly acts as a precursor of vapor nucleation with subsequent particles formation.
This specification covers a standard acrylonitrile butadiene (NBR-L) rubber stock with low acrylonitrile content in the form of molded test slabs.
This specification covers a fluorocarbon (FKM) rubber stock in the form of molded test slabs.
Drain and Fill plugs used on engines, transmissions, transfer cases and front and rear drive axles for class 5 – 8 vehicles.
This specification covers a standard fluoroelastomer (FKM) rubber stock in the form of molded test slabs.
This specification covers a polyalphaolefin/ester-blend fluid.
Recently, vehicle production volumes have been increasing, particularly in newly developing countries that often lack adequate infrastructure. These regions utilize many unimproved roads and frequently experience heavy rainfall, requiring robust product features. In contrast, developed countries, with well-maintained infrastructure, have emphasized protection of the environment, requiring automobile manufacturers to target reductions in carbon dioxide emissions. Hub unit bearings, which enable smooth wheel rotation, are mounted at the wheel center. The hub bearing is a critical part which supports the automotive body and requires high reliability. To make environmental progress, hub unit bearings have increasing requirements for low friction. NSK has developed effective grease technologies to meet the diverse requirements of hub unit bearings, such as high reliability and low friction under severe environmental conditions. Under wet operating conditions, the developed grease extended bearing life by using a unique composition of synthetic base oil with additives for water resistance which can separate water drops and form a thicker oxide film on the bearing raceways. At low speeds and heavy load conditions, the developed grease decreased friction torque via the base oil’s low viscosity-pressure coefficient. This paper reports the results of testing and observations completed for the developed grease.
Silicone fluids are known to have high Viscosity Indices (VI), and high Oxidation Onset Temperatures (OOT). Silicone VI and OOT characteristics make these fluids appealing for use as lubricants in high temperature applications, and where lubricant longevity is desired. Despite thermal and oxidative benefits, silicones lubricants have a reputation as being poor lubricants in metal-to-metal applications, and are typically only selected for use in plastic applications. Most industrial knowledge about silicone lubricants is based on characteristics of PolyDiMethyl Siloxanes (PDMS), in which case, lubricity limitations do exists. However, there are other silicone based lubricating fluid technologies, that have been commercially available for decades, that far exceed known lubricity performance of PDMS, and in some ways can rival traditional synthetic hydrocarbon. Phenyl-Methyl Silicones (PMS), Fluoro Silicones (FS), and Alkyl-Methyl Silicones (AMS) can offer great performance, at high temperatures, due to the high VI and OOT, for which silicones are known, and their molecular structures enable improved lubricity as compared to PDMS, giving these unique silicones combinatory benefits of thermal and oxidative stability, and lubricity even in metal-to-metal applications. This paper will discuss and compare different silicone-based fluids, as well as some comparison to polyalphaolefins, perfluoropolyethers, and other common synthetic lubricant technologies. Basic molecular structures will be reviewed, and comparative test data will be shared including SRV (Schwingungs-Reibungs und Verschleisstest) data, 4-Ball wear scar data, Viscosity Index, and Differential Scanning Calorimetry (DSC),. Following data sharing, a few potential high temperature applications ideas will be presented.
More stringent emissions regulations, fuel economy standards, and regulations are currently being discussed to help reduce both CO2 and exhaust emissions. Vehicle manufacturers have been developing new engine technologies, such as downsizing and down-speeding with reduced friction loss, improved engine combustion and efficiency, heat loss recycling, power-train friction loss recycling, and reduced power-train friction loss. The use of more efficient fuel economy 5W-30 engine oils for heavy duty commercial vehicles has started to expand since 2009 in Japan as one technological solution to help reduce CO2 emissions. However, fuel economy 5W-30 oils for use in heavy duty vehicles in Europe are mainly based on synthetic oils, which are much expensive than the mineral oils that are predominantly used in Japan. The main key technologies for mineral oil-based 5W-30 engine oils are the additive technologies used to determine the optimum conditions for the friction modifier, viscosity modifier, and HTHS viscosity in accordance with the lubrication conditions of the bearings, pistons, cylinders, and valve train on the Stribeck curve. A mineral oil-based 5W-30 engine oil is also required to have excellent detergency and anti-wear performance. This paper describes the evaluation of fresh engine oils using engine tests, with a particular focus on the viscosity index and HTHS viscosity to help determine the effect of these oils on improving engine fuel economy. The HTHS viscosity was evaluated at 150°C/107s−1 instead of the typical 150°C/106s−1. This paper also focuses on the boundary lubrication conditions and ways to improve fuel economy using the friction modifier. The fuel economy improvement effect was evaluated through engine tests after first confirming the friction reduction effect of the friction modifier through rig tests. Furthermore, an additional evaluation was carried out using carbon black to evaluate the effect of used oil under actual usage conditions. This research is expected to help contribute to the further expansion of the use of mineral oil-based 5W-30 engine oil in heavy duty diesel engines.
This specification covers a standard chloroprene (CR) rubber stock in the form of molded test slabs.
A team of engineers at Penn State, University Park, PA, is using squid to create an eco-friendly thermoplastic that can be used in 3D printing. Most plastics are made from fossil fuel sources or from synthetic oils. Thermoplastics can melt, be formed, and then solidify without degrading materials properties. The squid thermoplastic can be fabricated either as a thermoplastic, heated and extruded or molded, or be dissolved in a simple solvent and used in film casting. The researchers say that it can also be used in 3D printers to create complicated geometric structures.
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