MK Plastics DHK-NW IO&M - Manual (Page 5)

M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 5
Fan Bearing Lubrication
Proper lubrication of the fan drive bearings helps assure
maximum bearing life. DHK fans come with three types of
fan bearings:
1. Self-Lube pillow block ball bearings (1225-2225), which
do not require re-greasing. No grease fittings.
2. Air Handling Heavy Duty ball bearing pillow blocks
(1225-2225), which do require re-greasing. With grease
fittings - see schedule on Table 2.
3. Spherical split pillow block bearings (2450-6000), which
do require re-greasing through a grease fitting on the
outer housing and should be lubricated by the schedule,
Table 2.
However, every installation is different and the frequency
of relubrication should be adjusted accordingly. On high
moisture applications, the lubrication frequency may need
to be doubled or tripled to adequately protect the bearings.
Double the relubrication frequency on fans with vertical
shafts.
Observation of the conditions of the grease expelled from the
bearings at the time of relubrication is the best guide as to
whether regreasing intervals and amount of grease added
should be altered.
Greases are made with different bases. There are synthetic
base greases, lithium base, sodium base, etc. Avoid mixing
greases with different bases. They could be incompatible
and result in rapid deterioration or breakdown of the grease.
All bearings are filled with a lithium-based grease before
leaving the factory. When the fans are started, the bearings
may discharge excess grease through the seals for a short
period of time. Do not replace the initial discharge because
leakage will cease when the excess grease has worked out.
Sometimes the bearings have a tendency to run hotter during
this period. There is no reason for alarm unless it lasts over
48 hours or gets very hot (over 200°F). When relubricating,
use a sufficient amount of grease to purge the seals. Rotate
bearings by hand during relubrication.
Table 2 is for shaft bearings on belt drive and direct drive
arrangement #8 fans, motor bearing lubrication should be per
the motor manufacturers instructions.
Suggested initial greasing interval - remove bearing cap
and observe condition of used grease after lubricating.
Adjust lubrication frequency as needed. Hours of operation,
temperature, and surrounding conditions will affect the
relubrication frequency required. ‘If bearings need to be re
packed, remove old grease, pack bearing full and fill housing
reservoirs on both sides of bearing to bottom of shaft.’
Lubricate with a multipurpose roller bearing NLGI No. 2 having
rust inhibitors and antioxidant additives, and a minimum oil
viscosity of 500 SSU at 100ºF. Some greases having these
properties are:
1. Shell - Alvania No. 2 Mobil
2. Mobilith AW2/Mobilith SHC100
3. Texaco - Premium RB2
4. American - Rykon Premium 2
Lubricate bearings prior to extended shutdown or storage
and rotate shaft monthly to aid corrosion protection.
Fan Bearing Replacement
Table 2 - Relubrication Schedule [Months]
Figure 13
Split Pillow Block
Figure 14
Solid Pillow Block
Speed [rpm] 500 1000 1500 2000 2500 3000
Size
1225
1500
1825
2225
1225 6 6 5 3 3 2
1500 6 6 5 3 3 2
1825 6 6 5 3 3 2
2225 6 6 5 3 3 -
2450 6 4 4 3-1/2 2-1/2 -
2700 6 4 4 3-1/2 2-1/2 -
3000 5 4 3 2-1/2 - -
3300 5 4 3 2-1/2 - -
3650 5 4 3 - - -
4025 5 4 2-1/2 - - -
4450 4-1/2 3-1/2 2-1/2 - - -
4900 4-1/2 3-1/2 - - - -
5425 4-1/2 3-1/2 - - - -
6000 4-1/2 3-1/2 - - - -
Relubrication Schedule [Months]
For Bearings With No Grease Fittings
For Bearings With Grease Fittings
Relubrication is not required. Bearings are factory charged with the
correct amount of grease and do not require further grease charge.