Your Selections

Devlin, Mark
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Events

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Impact of Engine Oil Detergent on Low Speed Pre-Ignition (LSPI) and Fuel Economy Performance

Afton Chemical Corp.-Ashutosh Gupta, Mark Devlin
  • Technical Paper
  • 2020-01-1424
To be published on 2020-04-14 by SAE International in United States
Low Speed Pre-Ignition (LSPI), also referred to as Stochastic Pre-Ignition (SPI), Superknock or Megaknock is an undesirable combustion phenomenon that limits the fuel economy, drivability, emissions and durability performance of modern turbocharged gasoline engines. Numerous studies have previously reported that the frequency of LSPI is sensitive to engine oil composition. One of these drivers is the concentration of Calcium, which is usually delivered in the form of a detergent in the additive package. Switching to completely all-Magnesium detergent and/or severely limiting the concentration of Ca in the engine oil have recently been proposed as potential means to reduce LSPI. In this work, we evaluate the impact of detergent type on LSPI performance as well as on other performance that the modern engine oil needs to deliver. Particularly the impact of detergent type on Fuel Economy performance is evaluated. To ensure a rigorous and high precision measurement of the impact of engine oil on fuel economy, representative of real-world conditions, under well-controlled conditions, the ASTM D8114 test (Sequence VIE) was used to quantify fuel economy performance…
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Prediction of Friction Durability in Off-Road Applications Based on Mechanistic Understanding of the Effects of Fluids and Surfaces on Clutch Friction

Afton Chemical Corporation-Mark Devlin, Atanu Adhvaryu
Komatsu Ltd.-Shinpei Kariwa, Toshiharu Abekawa
  • Technical Paper
  • 2019-01-2339
Published 2019-12-19 by SAE International in United States
After new transmission lubricants are developed there is an extensive validation program where friction durability testing is performed on multiple clutch materials. Each durability test can run for long terms and the entire validation program can take much longer terms. A well designed lubricant and friction material will deliver the necessary friction control for construction equipment to operate at optimum level. A mechanistic construct has been evaluated to calculate friction durability in clutch systems based on fluid and surface tribological properties. Fluid properties include both boundary frictional and rheological effects. Surface properties include elastic modulus, surface roughness, asperity density and asperity tip radius. Using this mechanistic construct friction durability has been predicted. In the past, researchers in the field have often associated lubricant induced glazing of the friction material surface as the cause of the loss of friction control in clutch systems. In the current study, results show that wear is also a dominant cause of friction loss. In short clutch friction tests the rate of change in surface properties and fluid properties have been…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

The Effect of Friction Modifiers and DI Package on Friction Reduction Potential of Next Generation Engine Oils: Part II Aged Oils

Afton Chemical Corp.-William Lam, Mark Devlin
Ford Motor Company-Arup Gangopadhyay, Zhiqiang Liu, Steven Simko
Published 2019-04-02 by SAE International in United States
Engine oil plays an important role in improving fuel economy of vehicles by reducing frictional losses in an engine. Our previous investigation explored the friction reduction potential of next generation engine oils by looking into the effects of friction modifiers and dispersant Inhibitor packages when engine oil was fresh. However, engine oil starts aging the moment engine start firing because of high temperature and interactions with combustion gases. Therefore, it is more relevant to investigate friction characteristics of aged oils. In this investigation, oils were aged for 5000 miles in taxi cab application. The friction and wear protection characteristics were evaluated in laboratory bench tests i.e., MiniTraction Machine 2 under rolling/sliding conditions, lubricant film thickness measurements using ElastoHydrodynamic Lubrication (EHL) rig followed by tribo-film analysis by surface sensitive analytical techniques i.e., Auger and Time-of-Flight - Secondary Ion Mass Spectroscopies. Finally, the friction characteristics of aged oils were evaluated using a motored cranktrain rig. It was observed that aged oils took longer to form a protective tribo-film under rolling/sliding conditions and the composition of the film…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

The Effect of Friction Modifiers and DI Package on Friction Reduction Potential of Next Generation Engine Oils: Part I Fresh Oils

Afton Chemical Corporation-William Lam, Mark Devlin
Ford Motor Company-Zhiqiang Liu, Arup Gangopadhyay
Published 2018-04-03 by SAE International in United States
Friction reduction in lubricated components through engine oil formulations has been investigated in the present work. Three different DI packages in combination with one friction modifier were blended in SAE 5 W-20 and SAE 0 W-16 viscosity grades. The friction performance of these oils was compared with GF-5 SAE 5 W-20 oil. A motored cranktrain assembly has been used to evaluate these, in which friction mean effective pressure (FMEP) as a function of engine speeds at different lubricant temperatures is measured. Results show that the choice of DI package plays a significant role in friction reduction. Results obtained from the mini-traction machine (MTM2) provide detailed information on traction coefficient in boundary, mixed and elastohydrodynamic (EHD) lubrication regimes. It has been shown that the results from the cranktrain rig are fairly consistent with those found in MTM2 tests for all the lubricants tested. Analytical studies suggest that the traction coefficient increase in mixed lubrication regime is associated with the lubricant starvation due to the tribofilm formation. Oil film thicknesses have been measured as a function of rolling speeds at…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Metallurgy on the Formation of Tribofilms and Wear Prevention

Afton Chemical Corporation-Mark Devlin, Jeffrey Guevremont, Chip Hewette, Marc Ingram, Grant Pollard, William Wyatt
Published 2017-10-08 by SAE International in United States
Different mechanical components in a vehicle can be made from different steel alloys with various surface treatments or coatings. Lubricant technology is needed to prevent wear and control friction on all of these different surfaces. Phosphorus compounds are the key additives that are used to control wear and they do this by forming tribofilms on surfaces. It has been shown that different operating conditions (pressures and sliding conditions) can influence the formation of tribofilms formed by different anti-wear additives. The effect of surface metallurgy and morphology on tribofilm formation is described in this paper. Our results show that additive technology can form proper tribofilms on various surfaces and the right combination of additives can be found for current and future surfaces.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Effect of Fluid Flow through Clutch Material on Torque Fluctuations in Clutches

Afton Chemical Corporation-Mark Devlin, Darryl Williams, Michael Glasgow, Karen Hux, Aaron Whitworth
Miami University-Timothy Cameron
Published 2016-10-17 by SAE International in United States
Improving vehicle fuel efficiency is a key market driver in the automotive industry. Typically lubricant chemists focus on reducing viscosity and friction to reduce parasitic energy losses in order to improve automotive fuel efficiency. However, in a transmission other factors may be more important. If an engine can operate at high torque levels the conversion of chemical energy in the fuel to mechanical energy is dramatically increased. However high torque levels in transmissions may cause NVH to occur. The proper combination of friction material and fluid can be used to address this issue. Friction in clutches is controlled by asperity friction and hydrodynamic friction. Asperity friction can be controlled with friction modifiers in the ATF. Hydrodynamic friction control is more complex because it involves the flow characteristics of friction materials and complex viscosity properties of the fluid. This paper shows how NVH and torque capacity can be controlled by optimizing the flow characteristics of friction materials and the complex viscosity of fluids.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Lubricants for (Hybrid) Electric Transmissions

SAE International Journal of Fuels and Lubricants

Afton Chemical Corp.-Tom Hong-Zhi Tang, Mark Devlin, Naresh Mathur, Timothy Henly, Lee Saathoff
  • Journal Article
  • 2013-01-0298
Published 2013-04-08 by SAE International in United States
In electric or hybrid electric transmissions, the transmission fluids can be in contact with the parts of the electric motors, for example, electrical windings in the stators in order to efficiently cool the electric motors and to insulate the electrical parts to prevent a short circuit of the electric motors. The transmission fluids must therefore have low electrical conductivities [1,2,3,4,5,6,7,8,9]. Transmission fluids contain dispersants, which can be reaction products of hydrocarbyl substituted carboxylic acids or anhydrides and amines. These dispersants can be further post-treated with boron and phosphorus compounds to improve friction and anti-wear properties. Certain dispersants, which have nitrogen content up to 10,000 ppm by weight, and boron plus phosphorus to nitrogen ((B+P)/N) weight ratios of from 0.1 to about 0.8 : 1.0, were found to be effective to provide low electrical conductivities less than 1,700 pS/m [10]. Metal detergents provide good anti-rust performance, but increase the finished fluid electrical conductivity. A balanced dispersant/detergent additive system was found to provide a good anti-rust performance and a low electrical conductivity. Through extensive fluid engineering, a…
Annotation ability available