Page 330 - The Tribology Handbook

c7 Plain bearing lubrication

Table 7.3 Principal additives and Plain journal bearings
contaminants
Surface speed, u = ndn, ms-'
Problem Occurs in Requirements W
Mean pressure, 7 = -, kNm-*
Oxidation of IC engines Antioxidant Id
lubricant Steam turbines additives where
Compressors n = shaft speed, s-'
High-speed I = bearing width, m
gearboxes d =shaft diameter, m
W = load, kN
Scuffiing Gearboxes Extreme- Minimum allowable viscosity qmin., cP, may be read directly
Cam pressure
mechanisms additive

Deposit formation IC engines Dispersant
Compressors additives Plain thrust bearings
Excessive wear General Antiwear Surface speed, u = nDn, ms-'
of lubricated additives
surfaces Mean pressure 7 = KW, kNrn-'
ID
Water IC engines Good where n = shaft speed, s-'
contamination Steam turbines demulsification I = width of bearing ring, m
Compressors properties.
Turbine- D = mean pad diameter, m
quality oils W = thrust load, kN
(3
may be
required Minimum allowable viscosity qrhrust = qmin,
Dirt particle IC engines Dispersant
contamination Industrial plant additives
Weak organic IC engines Acid neutraliser
acid
contamination

Strong mineral Diesel engines Acid neutraliser Surface speed, ft/min
acid Process fluids 100 1000
contamination
Rusting IC engines Rust inhibitor
Turbines
Industrial plant 1 .o
General 000

1 00

10 1.01

11 1.001
0.1 1 .o 10.0 3' 3
Surface speed, mls
Figure 7.1 Lubricant wiscosity for plain bearings
C7.2