Wet clutch transmission fluid for AWD differentials: base fluid influence on friction characteristics

Mäki, Rikard; Ganemi, Bager; Olsson, Richard T.

doi:10.1002/tt.4

Cited by 12 publications

(9 citation statements)

References 10 publications

(17 reference statements)

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“…The investigated friction material is sintered bronze and the lubricant is a semisynthetic lubricant tailormade for the Haldex Limited Slip Coupling [11]; see fluid C in reference [12]. The separator disc in contact with the sintered bronze material is made from hardened steel.…”

Section: Boundary Lubrication Frictionmentioning

confidence: 99%

Wet clutch under limited slip conditions - simplified testing and simulation

Marklund

Larsson

2007

Proceedings of the Institution of Mechanical Engineers, Part J:

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When designing new wet clutch systems, simulations and laboratory tests are important to obtain a functional system. An engineering tool is here developed to simulate wet clutches working under boundary lubrication conditions. Boundary lubrication friction is measured by a pin-on-disc test, and cooling oil flow is simulated by solving the Reynolds equation. Depending on the generated heat, the temperature in the clutch pack changes during engagement, affecting the transferred torque. With the developed method it is possible to easily and quickly investigate the behaviour of wet clutches with a variety of friction materials and groove patterns. The model is validated in a wet clutch test rig and the predicted torque agrees well with experimental data.

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Section: Boundary Lubrication Frictionmentioning

confidence: 99%

Wet clutch under limited slip conditions - simplified testing and simulation

Marklund

Larsson

2007

Proceedings of the Institution of Mechanical Engineers, Part J:

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“…The transmitted torque is then measured by the torque measurement cell (7). The applied normal force is measured by the load cell (12); this is possible, thanks to the slider system (8), which allows the torsion bar and the torque cell to move freely in the axial direction. Both the force and the torque transducers are full bridge, strain-gauge type with builtin amplifiers.…”

Section: Test Equipmentmentioning

confidence: 99%

“…It was also concluded that the frictional characteristics were mainly additive dependent, since large differences in the friction parameters were seen in tests run at temperatures giving comparable viscosities. 12 …”

Section: Introductionmentioning

confidence: 99%

Wet clutch transmission fluid for AWD differentials: influence of lubricant additives on friction characteristics

Mäki

Ganemi

Höglund

et al. 2006

Lubrication Science

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In recent years, several electronically controllable automotive transmission systems using wet clutches as intelligent differentials have emerged on the market. These applications place great demands on the anti-shudder properties of the transmission fluids used.The aims of this study were (i) to investigate the influence of different additives on the friction characteristics of a transmission fluid for all-wheel drive systems featuring wet multi-plate clutch with a sintered brass-based friction material and, based on this knowledge, (ii) to formulate a new transmission fluid with the desired frictional properties. In addition to excellent anti-shudder properties, the new fluid was required to lubricate hypoid gears under high load. To meet this requirement, it is necessary to add significant amounts of extreme pressure additives to the base oil, which are known to have an unfavourable influence on anti-shudder properties, necessitating the adoption of novel additive technologies.The additives studied include anti-wear additives, friction modifiers, corrosion inhibitors, detergents, antioxidants and extreme pressure additives. This paper shows how different additives affect friction in different ways, and that the interactions between the different additives are important to consider. It was concluded that it is feasible to combine good anti-shudder properties for wet clutches with good lubrication of hypoid gears. Copyright

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“…Mäki et al. 11 and Scott et al. 12 investigated the base fluid and additive effects on frictional characteristics.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigations of tribological performances of novel friction pair with different conical configurations

Wang

2019

Proceedings of the Institution of Mechanical Engineers, Part J:

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Friction plate with conical configuration is a novel application in automatic transmission. In order to investigate the tribological performances of novel friction pair with different conical configurations, a series of tests are conducted by using a variable-speed friction test rig. The lubrication regime is evaluated by the friction coefficient curves under different loads. Test results of the friction coefficient under different rotating speeds are analyzed. The difference in the frictional behavior is analyzed for different conical friction pairs. The effects of the cone height and cone angle are evaluated under the same dimensions. Results show that changes in the conical configuration indeed influence the frictional behaviors of the friction specimens. Rational determination of the conical configuration is helpful to obtain good tribological performance.

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Wet clutch transmission fluid for AWD differentials: base fluid influence on friction characteristics

Cited by 12 publications

References 10 publications

Wet clutch under limited slip conditions - simplified testing and simulation

Wet clutch under limited slip conditions - simplified testing and simulation

Wet clutch transmission fluid for AWD differentials: influence of lubricant additives on friction characteristics

Experimental investigations of tribological performances of novel friction pair with different conical configurations

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