MODULE 3 (2.3) - GREASE AND SOLID LUBRICANTS

Question 1

it is a lubricating oil thickened with a gelling agent such as metallic soap or non melting powder

Answer 1

Grease

Question 2

used for low maintenance considerations, with lubricating design simplicity and decreased sealing requirements

Answer 2

Grease

Question 3

the thickener component maintains the contact between maintaining surfaces while the oil component forms the fluid lubricating film

Answer 3

Grease

Question 4

includes fatty acid soaps of lithium, calcium, aluminum and sodium in concentrations of 6 20 wt% with relatively low upper temperature limit of 65 80C

Answer 4

Thickener Component

Question 5

inorganic powders like bentonite clay are mixed with mineral oils to provide inexpensive, non melting greases with excellent water resistance at long lives up to about 140C

Answer 5

Thickener Component

Question 6

the shear stress applied to a fluid divided by the shear rate

Answer 6

Apparent Viscosity

Question 7

with units similar to absolute/dynamic viscosity, Pa-s or poise

Answer 7

Apparent Viscosity

Question 8

usually used on Non-Newtonian fluids

(those fluids with varying shear rates)

Answer 8

Apparent Viscosity

Question 9

in a fluid between two plates, one moving and one stationary (inducing shear on the fluid), it is the ratio of the velocity of the moving plate, divided by the distance between the plate, or the fluid thickness, with a unit of 𝑠−1

Answer 9

Shear Rate

Question 10

for Non Newtonian fluids, this is varying with relation to stress. Newtonian fluids (the common ones) have a constant viscosity independent of stress

Answer 10

Shear Rate

Question 11

Greases behave in a _____ manner

Answer 11

Non-Newtonian

Question 12

provide thin films of a solid between two moving surfaces, usually at environments not ideally tolerated by conventional oil and greases

Answer 12

Solid Lubricants