A Comparison of Methods for Evaluating Automatic Transmission Fluid Effects on Friction Torque Capacity - A Study by the International Lubricant Standardization and Approval Committee (ILSAC) ATF Subcommittee

Linden, James L.; Doi, Jyunichi; Furumoto, Mitsumasa; Hoshikawa, Nobuyoshi; King, Tracey; Kurashina, Hideo; Murakámi, Yasuhiro; Sprys, J. W.; Ueda, Fumio

doi:10.4271/982672

Cited by 4 publications

(4 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There have been several experiments on the development of a wet clutch test rig appropriate for certain applications. [1][2][3][4][5][6][7]9,19,22 The test rig used in this investigation has been designed to investigate the friction characteristics of a single clutch contact. The test parameters of the rig can be controlled in a range described in Table 1.…”

Section: Test Rigmentioning

confidence: 99%

“…1,[4][5][6] The clutch's capacity for transferring the required amount of torque from the engine as well as the ultimate clutch life depends mainly on the frictional Division of Machine Elements, Luleå University of Technology, Sweden characteristics. 2,3,7 So, friction stability with adequate torque generation is a primary requirement for the appropriate clutch performance.…”

Section: Introductionmentioning

confidence: 99%

“…It serves as a coolant as well as controlling frictional behaviour for smooth clutch operation. Lubricant chemistry, viscosity, performance and durability of the clutch are extensively related with the friction performance, 1,[6][7][8][9] along with other contributing factors (operating conditions like load, speed, temperature; friction material, groove pattern, surface roughness). 3,[10][11][12][13][14][15][16] A good ATF should be thermally stable and chemically compatible with the friction materials and other transmission components.…”

Section: Introductionmentioning

confidence: 99%

“…Degraded lubricant can contribute to the failure of clutch friction performance as well be responsible for unwanted occurrences, such as high friction in the low speed range and low friction in the high speed range (negative m-v characteristics) that may result in shudder. [4][5][6][7][8] The lubricant can be degraded by thermal breakdown of the lubricant additive package, change in fluid property due to oxidation and contamination. Contamination in any transmission system is a very common reason for improper lubricant function.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Water contamination effect in wet clutch system

Fatima

Marklund

Larsson

2012

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

Water contamination in wet clutch systems can be a problem since both torque characteristics and wear resistance can be influenced by the presence of water. The present paper reveals the effect of externally added water on the wet clutch frictional performance. Commercially available standard paper-based friction plates and steel separator plates lubricated with commercially available automatic transmission fluid were investigated in a recently developed automated test rig using a well-confined experimental approach. Frictional response was observed for three different situations with different amounts of water and different exposure times. An undesirable friction increase is observed with increasing amounts of water in the system. The rate of increase in friction coefficient does not linearly depend on the amount of added water, and this is a noticeable outcome from the common possible water contamination effects, such as change in lubricant viscosity, inadequate additive performance and weakening of the friction material. The greater reduction in the separator plates' surface roughness (R a ) in a water contaminated clutch system compared to an uncontaminated one may be a reason for the change in friction. It is also shown that different water exposure time has no great impact on the change in friction level and the separator plates' roughness.

show abstract

Section: Test Rigmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Water contamination effect in wet clutch system

Fatima

Marklund

Larsson

2012

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

show abstract

Mechanical–Dynamic Tribology and Testing Methods

Mang

Bobzin

Bartels³

2010

Industrial Tribology

View full text Add to dashboard Cite

Tribochemistry on Clutch Friction Material Lubricated by Automatic Transmission Fluids and the Link to Frictional Performance

Zhao¹,

Morina²,

Neville

et al. 2013

Journal of Tribology

View full text Add to dashboard Cite

Automatic transmissions (AT) for passenger cars are becoming more popular globally, including some countries that traditionally prefer manual transmissions. Some new friction modifiers for transmission fluid technologies have also emerged due to the downsizing trend of transmissions. In order to study the tribology and tribochemistry effects of some new automatic transmission fluid (ATF) additive formulations, both steel and wet-clutch friction materials were assessed by using surface analysis techniques. A variable speed friction test (VSFT) rig was used to study the antishudder properties in lock-up clutch tests and friction modifying mechanisms of ATFs. A test oil matrix containing basic ATF components was tested. The friction results were analyzed using both the linear-defined multiple parameter spider chart ATF evaluation (LSAE) method (Zhao et al., 2008, “A New Method to Evaluate the Overall Anti-Shudder Property of Automatic Transmission Fluids—Multiple Parameters Spider Chart Evaluation,” Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol., 222(J3), pp. 459–470) and the friction coefficient ratio index method (Zhao et al., 2011, “Understanding Friction Behavior in Automatic Transmission Fluid LVFA Test: A New Positive Curve Parameter to Friction Coefficient Ratio Index Evaluation,” ASME J. Tribol., 133(2), p. 021802) (e.g., μ1/μ50 on the low-velocity friction apparatus (LVFA) μ-v curve results to compare the overall tribosystem and the snapshot friction performance during the test). Surface analysis results were obtained by using X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectroscopy (ToF-SIMS), and attenuated total reflectance Fourier transformed infrared spectroscopy (ATR FT-IR), and they are presented in this study to investigate the tribofilm compositions formed by different additive formulations. Some organic functional groups were found at the sample surfaces, such as –OH and O–C–O, and their presence is proposed to have a beneficial influence on the ATF friction performance. This paper discusses the surface analysis results of the test sample pieces, the possible links between specific functional groups and friction performance, and the proposed pathways of additive decompositions by using chemical bond dissociation energy comparisons.

show abstract

A Comparison of Methods for Evaluating Automatic Transmission Fluid Effects on Friction Torque Capacity - A Study by the International Lubricant Standardization and Approval Committee (ILSAC) ATF Subcommittee

Cited by 4 publications

References 2 publications

Water contamination effect in wet clutch system

Water contamination effect in wet clutch system

Mechanical–Dynamic Tribology and Testing Methods

Tribochemistry on Clutch Friction Material Lubricated by Automatic Transmission Fluids and the Link to Frictional Performance

Contact Info

Product

Resources

About