Lubricating grease shear flow and boundary layers in a concentric cylinder configuration

• Grease is extensively used to lubricate various machine elements such as rollingbearings, seals, and gears. Understanding the flow dynamics of grease is relevant forthe prediction of the grease distribution for optimum lubrication and the migration ofwear- and contaminant particles. In this study grease flow is visualized using themethod of micro Particle Image Velocimetry; the experimental setup comprises aconcentric cylinder with rotating shaft to simulate the grease flow in a DoubleRestriction Seal (DRS) geometry with two different grease pocket heights. It is shownthat grease may be partially yielded in the large grease pocket geometry and fullyyielded in the small grease pocket geometry. For the small grease pocket geometry, itis shown that three distinct grease flow layers are present: a high shear rate regionclose to the stationary wall, a bulk flow layer, and a high shear rate boundary regionnear the rotating shaft. The grease shear thinning behaviour and its wall slip effectshave been detected and discussed.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Tribologi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Tribology (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Keyword

Maskinelement

Machine Elements

Strömningslära

Fluid Mechanics

Publication and Content Type

ref (subject category)

kon (subject category)