Lubrication

Question 1

Kinematic Visc

Answer 1

ν = μ / ρ

Question 2

Dynamic Visc

Answer 2

μ = (F / A) / (U / h)

Question 3

Abs. viscosity @ given P

Answer 3

μ p = μK * exp(Υ*P)

μK - abs visc at atm pressure
Y - (gamma) pressure coefficient of viscosity
P - applied pressure

Question 4

Load capacity in journal bearing

Answer 4

P = W / (LD)

Question 5

Bearing parameter journal bearing

Answer 5

μ N / P

Question 6

PV factor

Answer 6

P * V

Question 7

Friction force #1, journal

Answer 7

F = (μ A U) / h

Question 8

Contact area, journal bearing

Answer 8

Area = 2pi R L

or

Area = pi D L

Question 9

Velocity, journal bearing

Answer 9

V = 2pi R n

or

V = pi D n

Question 10

Height is equivalent to …. in journal bearings

Answer 10

radial clearance, c

Question 11

Radial clearance, journal

Answer 11

c = (bearing diam. - shaft diam.) / 2

Question 12

Friction force #2, journal

Answer 12

F = Tf / R

Tf is friction torque

Question 13

Tf in friction force eqs, journal

Answer 13

Tf = (4(pi)^2 μ n R^3 L) / c

Question 14

Clearance ratio, journal

Answer 14

R / c

Question 15

Coefficient of friction, Petroff’s eqs, journal

Answer 15

f = 2(pi)^2 (μ n / P) (R / c)

aka f = 2(pi)^2 * (bearing parameter) * (clearance ratio)

Question 16

Alt. friction torque eqs, journal

Answer 16

Tf = f W R = f (D L P) R

Question 17

Epsilon symbol is for

Answer 17

eccentricity ratio

Question 18

Power, journal

Answer 18

P = ω T = 2pi Ns T