AEC AG Auger Series Granulator - Manual (Page 22)

6.5” Granulators Chapter 5: Maintenance 21 of 35
5-6 Lubrication Requirements
All granulator and motor bearings are shipped pre-lubricated from the factory.
The bearings used require a high quality, lithium-based EP (extreme pressure) type of grease,
which conforms to the NGLI Grade 2 consistency. This grease has been chosen due to its
suitability for use in heavy-duty applications under heavy shock loads. It also contains rust
inhibitors, has high temperature stability, and exhibits good water resistance. For normal
operating conditions, the grease should be free of any chemical impurities such as free acid or
free alkali, dust, rust, metal particles, or abrasives.
Bearings must be re-lubricated periodically to assure long life. The length of intervals
between greasing depends on the running speed and atmospheric conditions. See Figure 2 to
determine the proper greasing interval.
For best results, bearings should be re-lubricated while in operation. The grease should be
pumped in slowly until a slight bead forms around the seals. This bead, in addition to acting
as an indicator of adequate re-lubrication, provides additional protection against the entry of
foreign matter.
By the time the slight grease bead is formed, it will be noted that the temperature rise is
approximately 30ºF. If necessary to re-lubricate while the bearing is idle, refer to the re-
lubrication table in Figure 3 for the maximum grease capacity for various sizes of bearings.
Bearings should be lubricated with care. Too much grease applied to the bearings at one time
can rupture bearing seals.
Grease in bearings prevents excessive wear of parts, protects ball races and balls fro
corrosion, and aids in heat dissipation within the bearing. The motors should be lubricated to
their manufacturers specifications.
Figure 2: Greasing Intervals by Operating Conditions
Bearing Temperature Cleanliness Greasing Interval
Up to 120º F Clean 6 to 12 months
Up to 150 º F Clean 2 to 6 months
Up to 210º F Clean 2 weeks to 2 months
Over 210º F Clean Weekly
Up to 150º F Dirty 1 week to 1 month
Over 150º F Dirty Daily to 2 weeks
Any temperature Very Dirty Daily to 2 weeks
Any temperature Extreme Conditions Daily to 2 weeks
Figure 3: Approximate Grease Capacity of Bearings
Shaft Size Typical Grease Capacity of Bearing Chamber in Ounces
1/2” to 3/4” 1/4
7/8” to 1-3/16” 3/8
1-1/4” to 1-1/2” 5/8
1-11/16” to 1-15/16” 5/8
2” to 2-7/16” 3/4
2-1/3” to 2-15/16” 1-1/2
3” to 3-7/16” 2
3-1/2” to 4” 2-1/2
4-3/16” to 4-15/16” 3