Page 49 - The Tribology Handbook

A7 Grease, wick and drip fed journal bearings

Table 7.8 The comparative performance of various wick and packing materials

Felt, high densitv Felt, low dmig
TVPe (sg 3.4) (sg 1.8 to 2.8) Gilled thread Wool waste Cotton lamp wick
Height of oil lift (dependent Very good Fair Good Poor Fair
on wetting and size of
capillary channels)
Rate of flow Very good Fair Good Poor Fair
Oil capacity Low High Low Moderate (3 times Fair
weight of waste)
Suitability for use as packing Poor (tendency to Poor (tendency to Poor Good (superior Poor
glaze) glaze) elasticity)

4.0

3.5

3.0

$-
E 2.5
W
2
E
> 2.0
a:
W
2
1
W
1.5
1 .O

0.5

0
0 5 10 15 20 25 30-
L, WlCKlNG DISTANCE, crn
150 c Fig. 7.8. Oil delivery rates for SAE F1 feEt wicks,

density 3.4gl cc. cross-sectional area 0.65cm2
120 1 (0.1 id), temperature 21°C, viscosity at 40°C
(IS0 3448) (Data from the American Felt Co.)
n

Fig. 7.9. Effect of drop rate on oil drop size, temp-
erature 2PC. Oil viscosity and lubricator tip
shape have little effect on drop size over the
normal working ranges

0.3 0.9 1.5 2.1 2 .?
DROP RATE, DROPS/SECOND A7.7