Frictional Properties of Automatic Transmission Fluids: Part I—Measurement of Friction–Sliding Speed Behavior

Ingram, M.; Noles, J.; Watts, Raymond F.; Harris, Steven G.; Spikes, H. A.

doi:10.1080/10402004.2010.531888

Cited by 48 publications

(34 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effect of an ester and amine type OFMs on the anti-shudder property was examined using the clutch friction tester, and it was found that the performance is dependent on the temperature conditions as well as the polar group structure of the OFMs. In the study of Ingram et al [11], the similar results regarding the influence of temperature on the clutch friction are also reported. This temperature dependence of the OFMs is considered to be a disadvantage for achieving the target clutch frictional properties in a wide range of the driving conditions, and it is ideal to show a stable performance independent on temperature.…”

Section: Introductionsupporting

confidence: 71%

Advanced Control of Frictional Properties on Paper Clutch Materials by a Combination of Friction Modifiers

2017

View full text Add to dashboard Cite

This study proposes a novel approach for controlling frictional performances at paper clutch systems by a combination of organic friction modifiers (OFMs). The OFMs are commonly used for modifying the frictional properties at the paper clutch. Although the effect of the OFMs tends to be dependent on temperature due to their working mechanism based on the surface adsorption, the frictional properties are preferable to be stable in all the operating temperature for the consistent and precise clutch control. Aiming to modify the temperature dependence of the OFM effect, an OFM with an Advanced Concept (FMAC) was newly developed, and the impact on the clutch frictional performance was investigated using Low Velocity Friction Apparatus (LVFA). Only with the conventional OFM, the friction values experienced excessive reduction at 80 or 120°C, while an optimal property was achieved at 40°C. In the presence of the FMAC, it was possible to inhibit the conventional OFM selectively at the high temperature conditions preventing the friction reduction, leading to the ideal frictional property in all the temperature conditions. The surface analysis revealed that the FMACs were capable of adsorbing on the substrate more intensively at high temperature, which should be the reason of the temperature dependent competitive effect of the FMACs.

show abstract

Section: Introductionsupporting

confidence: 71%

Advanced Control of Frictional Properties on Paper Clutch Materials by a Combination of Friction Modifiers

2017

View full text Add to dashboard Cite

show abstract

“…This behaviour is shown for stearic and elaidic acid solutions in Fig. 8 and is often seen in boundary lubrication [110][111][112]. In this model the energy required for methyl groups to traverse the potential energy barriers created by the methyl groups on the opposing surface is provided by a combination of the work done and thermal energy.…”

Section: Origins Of Monolayer-monolayer Frictionmentioning

confidence: 93%

Friction Modifier Additives

2015

View full text Add to dashboard Cite

The need for energy efficiency is leading to the growing use of additives that reduce friction in thin film boundary and mixed lubrication conditions. Several classes of such friction modifier additive exist, the main ones being organic friction modifiers, functionalised polymers, soluble organo-molybdenum additives and dispersed nanoparticles. All work in different ways. This paper reviews these four main types of lubricant friction modifier additive and outlines their history, research and the mechanisms by which they are currently believed to function. Aspects of their behaviour that are still not yet fully understood are highlighted.

show abstract

“…This behaviour appears to depend strongly on the ability of the surfactant to form a close-packed monolayer, so that if this layer is disrupted in some fashion, friction tends to become independent of speed. Thus Ingram et al found that some blends of low and high chain length fatty acids gave speed-independent friction even though solutions of the individual acids gave logarithmic dependence [86]. Campen et al found that while oleic acid solutions gave friction constant with speed, the same concentration of its trans-isomer, elaidic acid, showed logarithmic dependence, similar to stearic acid [87].…”

Section: Boundary Frictionmentioning

confidence: 99%

Stress-augmented thermal activation: Tribology feels the force

2018

View full text Add to dashboard Cite

Abstract:In stress-augmented thermal activation, the activation energy barrier that controls the rate of atomic and molecular processes is reduced by the application of stress, with the result that the rate of these processes increases exponentially with applied stress. This concept has particular relevance to Tribology, and since its development in the early twentieth century, it has been applied to develop important models of plastic flow, sliding friction, rheology, wear, and tribochemistry. This paper reviews the development of stress-augmented thermal activation and its application to all of these areas of Tribology. The strengths and limitations of the approach are then discussed and future directions considered. From the scientific point of view, the concept of stress-augmented thermal activation is important since it enables the development of models that describe macroscale tribological performance, such as friction coefficient or tribofilm formation, in terms of the structure and behaviour of individual atoms and molecules. This both helps us understand these processes at a fundamental level and also provides tools for the informed design of lubricants and surfaces.

show abstract

Frictional Properties of Automatic Transmission Fluids: Part I—Measurement of Friction–Sliding Speed Behavior

Cited by 48 publications

References 21 publications

Advanced Control of Frictional Properties on Paper Clutch Materials by a Combination of Friction Modifiers

Advanced Control of Frictional Properties on Paper Clutch Materials by a Combination of Friction Modifiers

Friction Modifier Additives

Stress-augmented thermal activation: Tribology feels the force

Contact Info

Product

Resources

About