Sterlco HDG Series Heavy Duty Granulators - Manual (Page 22)

Bulletin Number Chapter 5: Maintenance 22 of 36
The period during which a grease-lubricated bearing will function satisfactorily without re-
lubrication depends on the bearing type, size, speed, operating temperature, and the grease
used. Re-lubrication intervals (hours of operation) are valid for bearings in machines where
loading conditions are normal: an age-resistant, average quality grease is used and the
operating temperature is below 158°F (70°C) measured at the outer ring.
Re-lubrication intervals should be halved for every 27°F (15°C) increase in the temperature
above 158°F (70°C). The maximum permissible operating temperature for the grease must
not be exceeded.
Note: Re-lubrication intervals may vary significantly even where apparently similar
greases are used.
Where there is a high risk of the grease becoming contaminated, the re-lubrication frequency
should be increased. This reduction also applies to applications where the grease is required
to protect against moisture. These bearings should be re-lubricated once a week.
We recommend using 2-4 ounces of grease when re-lubricating. Recommended grease are
Sun Presitge #741EP or Mobilux EP2.
5-3 Replacing and Adjusting the Knives
During use, the clearance between the rotor knives and the bed knives will increase due to
wear. This is a normal condition that requires re-setting this clearance once or twice before it
is necessary to remove the knives for regrinding. Check the knives weekly for wear,
clearance, exposure and screw tightness.
When new knives are fitted to the machine, adjustment after eight hours of running time may
be required.
Before assembling a new or reground set of knives, make sure the knife seats and mounting
holes are clean. Do not use grease or oil on screws or tapped holes when assembling the
knives.
Knives must be replaced in complete sets; otherwise it will not be possible to obtain even
clearance between the rotor knives and bed knives.
Before applying a wrench to any knife bolt, be certain that the rotor is
blocked to prevent rotation. One such method is to use a block of wood at
least 1 1/2” thick between a knife and a fixed portion of the frame.
Rotor Knives
We recommend that the rotor knife screws be replaced with new screws every sixth knife
change to reduce the risk of screw failure due to overstretching. Screws must be replaced
with the type specified in the spare parts list. Use the procedure to replace or adjust the rotor
knives.
Rotor knives should be changed one seat at a time to prevent rotor from
being rotated in and out-of-balance condition.
1. Access the cutting chamber as directed in Section 3-4 on page 15.
2. Loosen check nuts on bed knife adjusting screws and back off screws
3. Remove bed knife shields.
4. Disengage bed knife pull screws
5. Remove the bed knife bolts and bed knives.