Page 48 - The Tribology Handbook

rease, wick and drip fed journal bearings A7

FELT PAD
W W
J-

NDERFED
W
W
FROM LUBRICANT
SUPPLY
OP WICK MATIC
RESERVOIR) D

'I .) .)
w W W W
Fig. 7.7 Typical lubricant feed arrangements

Table 7.7 Guidance on the choice of lubricant feed system

Lubricant supply 'Toleration of dirg Maintenance needs
method Cost environment rating LubricantJow characteristics
- ~-
Wool waste Cap i 11 a ry Expensive Fair. Waste acts Good. Infrequent Very limited rate controlled by
In bricated housing design as an oil filter refilling of height of oil in reservoir. Recir-
reservoir culation possible. Varies auto-
matically with shaft rubbingspeed.
Stops when rotation ceases
______. -~
Wick lubricated Capillary and, Moderate Fair. Wick acts Good. Infrequent Limited rate and control (ref. Fig. 7.8).
(with reservoir) siphonic as an oil filter refilling of oil Recirculation possible with un-
reservoir derfed wick type. Varies slightly
with shaft rubbing speed. Under-
fed type stops when rotation
ceases (not siphonic)
__.___~ __ __-~ ___
Wick or pad Capillary Cheap Fair. Wick act Fair, Reimpreg- Very limited rate, decreasing with
lubricated (no as an oil filter nation needed use. Varies slightly with shaft
reservoir) occasionally rubbing speed. Stops when
rotation ceases. Recirculation
possible
.... ~ ~___ ~ __
..
Grcase lubricaied Hand-operated Very cheap Good. Grease Poor. Regular Negligible flow, slumping only.
qrr.3ac gun or acts as a seal regreasing Kheodynarnic, Le. no flow at low
screw cup needed shear stress hence iittle end flow
loss from bearing
__ . -~ ~__--__-
i).+ii€d Gravity; through Chrap for simple Poor 'J~jor. Regular Variable supply rate. Constant flow
luhricatcc! a controlled installations refilling of at any setting. Total loss, Le. no
orifice reservoir recirculation. Flow independent
needed Df rotation
~
Autoniaric feed Pump-rippiiecl Expensivr ancil- Fir Good. Supply Wide range of flow rate. Can vary
;oil c1r grease) pre>sure iary equipment systern needs Automaticaliy. Total loss. Can
needed occasional stop or start independently of
atlention rotation
__ _______ _____ .-. . __ _-
A7.6