Sterlco HDG Series Heavy Duty Granulators - Manual (Page 21)

Bulletin Number Chapter 5: Maintenance 21 of 36
Chapter 5: Maintenance
5-1 Preventative Maintenance Schedule
Check Frequency
Knife clearance Weekly
Knife retaining screws for tightness Weekly
Knife exposure Weekly
Shield retaining screws for tightness Weekly
Screen retaining studs fro tightness Weekly
Lubrication of drive motor bearings Monthly
Lubrication of rotor bearings Monthly
Screen Wear Monthly
Belt Tension Monthly
Hopper and cutting chamber screws are tight Monthly
5-2 Lubrication
Lubrication of rotor bearings should be based on the size and type of bearing, the RPM at
which the rotor is turning, and the temperature at which the bearing is operating.
The size of the bearing will determine the amount of grease required. The RPM, bearing type,
and size of the bearing will determine the frequency of lubrication. Higher than normal
temperatures will determine the amount of grease required.
New Bearings
Bearings are initially lubricated at the factory prior to shipment. However, when assembling
new bearings and before bearing caps are installed, fill every third cavity of the bearing using
a hand grease gun, and then rotate the shaft by hand to distribute the grease. Fill the bearing
cavity 1/3 full of grease.
A hand-operated grease gun is preferred over a power grease gun because of better control of
pressure and quantity dispensed. This tends to prevent over-greasing and damage to seals.
Run the machine and observe drainage from the bearing housing. If a soupy discharge is
observed (indicating oil separation), then add a couple of sots of grease from a hand gun at
intervals until the discharge is no longer soupy.
Re-Lubrication
A new granulator rotor bearing should be greased after the first two weeks of operation, and
then re-lubricated every 2-4 weeks, depending on the duty cycle. Continuous operation (24
hours a day) at a maximum capacity would require lubrication every 2 weeks. Internittent
operation and/or light duty intervals could require lubrication every 4 weeks.