as compatible may be incompatible due to ad-
verse reactions between the thickening agent of
one grease and additives In the other. In rare
cases, greases with the same thickening agent,
but made by different manufacturers, may be
incompatible due to the additives.
verse reactions between the thickening agent of
one grease and additives In the other. In rare
cases, greases with the same thickening agent,
but made by different manufacturers, may be
incompatible due to the additives.
If It becomes necessary to change the grease
type used in a piece of equipment, if at all
possible, the bearing housing or the area being
greased should be thoroughly cleaned to re-
move all of the old grease. If this is not possible,
as much as possible of the old grease should be
flushed out by the new grease during the initial
application and the greasing frequency should
be increased until it is determined that all of the
old grease has been purged from the system.
type used in a piece of equipment, if at all
possible, the bearing housing or the area being
greased should be thoroughly cleaned to re-
move all of the old grease. If this is not possible,
as much as possible of the old grease should be
flushed out by the new grease during the initial
application and the greasing frequency should
be increased until it is determined that all of the
old grease has been purged from the system.
5.3 Grease Application
The most common problem with the grease
lubrication of antifrictlon bearings (ball and roller
bearings) is over-lubrication. Excess grease will
churn within the bearing housing, and cause
excessive heat, which can soften the grease,
reducing its effectiveness and lead to bearing
damage. The heat can also cause the grease to
expand, increasing the temperature further and
create enough pressure to damage the bearing
seals.
lubrication of antifrictlon bearings (ball and roller
bearings) is over-lubrication. Excess grease will
churn within the bearing housing, and cause
excessive heat, which can soften the grease,
reducing its effectiveness and lead to bearing
damage. The heat can also cause the grease to
expand, increasing the temperature further and
create enough pressure to damage the bearing
seals.
Ideally a grease lubricated antifriction bearing
should be "packed" by hand so that the bearing
housing is approximately one third full of grease.
The bearing housing should be opened, the
bearing and all of the old grease removed, and
the bearing and the housing thoroughly cleaned.
should be "packed" by hand so that the bearing
housing is approximately one third full of grease.
The bearing housing should be opened, the
bearing and all of the old grease removed, and
the bearing and the housing thoroughly cleaned.
Compressed air should not be used for cleaning
or drying the bearing as moisture In the air may
Induce corrosion In the highly polished bearing
surfaces. When clean, the bearing should be
thoroughly packed in new grease and the
bearing housing filled one third full of grease.
It is not always practical or possible to hand
pack a bearing. In these cases grease guns or
other high pressure device may be used. Cau-
tion should be exercised when using high
pressure systems to prevent over-greasing or
over-pressuring the bearing. When grease is
applied using a grease gun, the relief plug, If so
equipped, should be removed so that as the new
grease is applied, all of the old grease is purged
from the bearing housing. The machine should
be operated approximately 30 minutes before
the plug is replaced to allow excess grease to
escape. If the bearing housing doesn't have a
relief plug, grease should be added very
infrequently to prevent over lubrication, and
after grease is added, the pressure fitting or
"zerk" should be removed to prevent pressure
retention.
or drying the bearing as moisture In the air may
Induce corrosion In the highly polished bearing
surfaces. When clean, the bearing should be
thoroughly packed in new grease and the
bearing housing filled one third full of grease.
It is not always practical or possible to hand
pack a bearing. In these cases grease guns or
other high pressure device may be used. Cau-
tion should be exercised when using high
pressure systems to prevent over-greasing or
over-pressuring the bearing. When grease is
applied using a grease gun, the relief plug, If so
equipped, should be removed so that as the new
grease is applied, all of the old grease is purged
from the bearing housing. The machine should
be operated approximately 30 minutes before
the plug is replaced to allow excess grease to
escape. If the bearing housing doesn't have a
relief plug, grease should be added very
infrequently to prevent over lubrication, and
after grease is added, the pressure fitting or
"zerk" should be removed to prevent pressure
retention.
Grease lubricated bushings or journal bearings
are not as sensitive to over-lubrication as
antifriction bearings so "hand packing" is not
usually necessary. The most common method of
applying grease to a journal bearing Is by a high
pressure system. This may be a centralized,
automatic system, as is used on turbine wicket
gates, or it may be a simple grease gun. Over-
greasing with a high pressure system will not
normally damage the bearing, but it can damage
seals, waste grease, and cause a mess.
are not as sensitive to over-lubrication as
antifriction bearings so "hand packing" is not
usually necessary. The most common method of
applying grease to a journal bearing Is by a high
pressure system. This may be a centralized,
automatic system, as is used on turbine wicket
gates, or it may be a simple grease gun. Over-
greasing with a high pressure system will not
normally damage the bearing, but it can damage
seals, waste grease, and cause a mess.
(FIST 2-4 11/90)
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