Page 331 - The Tribology Handbook

Plain bearing lubrication e7

Table 7.4 Resistance to corrosion of bearing metals

Maximum Additive or contaminant
Lrnperature, Extreme-pressure Weak organic Strong mineral Synthetic
“C additive Antioxidant acidc acids oil
Lead-base white metal 130 Good Good Moderatelpoor Fair Good

Tin-base whi1:e metal 130 Good Good Excellent Very good Good
Copper-lead (without overlay) 170 Good Good Poor Fair Good
Lead-bronze (without overlay) 180 Good with good Good Poor Moderate Good
quality bronze
Aluminium-tin alloy 170 Good Good Good Fair Good

Silver 180 Sulphur-contain- Good Good-except Moderate Good
ing additives tor sulphur
must not be
used
Phosp hor-bronze 220 Depends on Good Fair Fair Good
quality of
bronze. Sulphur-
ised additives
can intensifv
corrosion
Copper-lead or lead-bronze 170 Good Good Good Moderate Good
with suitable overlay

Note: corrosion of bearing metals is a complex subject. The above offers a general guide. Special care is required with extreme-pressure
lubricants; if in doubt refer to bearing or lubricants supplier.

10 000
5000
3000
2000
1000

500
300 Bearing temp era ture
0
- 200
i Lubricant supply rate should be sufficient to restrict the
4-
‘;i 100 temperature rise through the bearing to less than 20°C.
5!
._ A working estimate of the mean bearing temperature,
>
.o 50 is given by
E ebenring = 6svpply + 20, “c
5 30
0
20
10
7
Dynamic and Kinematic Viscosity
5
4 1 - Dynamic Viscosity, q (cP)
-1 0
Temperature, ‘C = Density X Kinematic Viscosity (cst)
Figure 7.2 Typical viscosity,’temperature Viscosity classification grades are usually expressed in
characteristics of mineral oik terms of Kinematic Viscosities.
c7.3