AEC AG Auger Series Granulator - Manual (Page 24)

6.5” Granulators Chapter 5: Maintenance 23 of 35
5-8 Replacing and Adjusting the Knives
The rotor and bed knives are subjected to severe conditions, and you should inspect knives
periodically for sharpness. The sharper the knives are kept, the better the machine operates,
producing quality regrind. If the knives become severely rounded, chipped, or otherwise
damaged, the granulator experiences heavy shock loads during operation causing additional
and significant reduction in knife life.
WARNING! Exercise extreme care when rotating the rotor and handling knives.
All flange-type bearings are centered, drilled, and pinned at assembly of the unit. Should it
become necessary to replace these bearings, it will be the customer’s responsibility to center,
drill, and pin the bearing in position.
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 following procedure to replace or adjust
the rotor combs:
Caution! Rotor knives should be changed one seat at a time to prevent rotor from
being rotated in an out-of-balance condition.
1. Access the cutting chamber as directed in Section 3-4 on page 15.
2. Set back the bed knives to clear the rotor knives so that the rotor can revolve freely.
3. Carefully block the rotor with a piece of wood to prevent it from turning.
4. Loosen and remove the rotor knife screws (See Figure 5 on page 24) and carefully
remove all rotor knives. Make sure you have solid footing while you apply the
breaking force.
5. Thoroughly clean the knife seats with a stone or other non-marring tool, and wipe the
screws with a lightly oiled cloth. Do not leave an oil film on the screws, as
lubrication can adversely affect the stress on a screw installed to a fixed torque value.
6. Re-install the rotor knives onto the rotor.
7. Lightly tighten the screws and check that a 0.03 mm (0.0015”) feeler gauge will not
pass between the back of the knife and the knife seat. Tap the knife gently with a
rawhide hammer if necessary to close the gap.
8. Tighten the screws evenly and torque the screws according to Section 7-3 on page 34.
9. Re-check the gap between the back of the knives and the knife seats. If necessary,
readjust the knives.
6. Adjust the clearance between the bed knives and rotor knives. (See “Bed Knives” on
page 24.)