F
OR
M
ODELS
: JGI, JGM, JGN, JGP
AND
JGQ
PAGE 4-1
S
ECTION
4 L
UBRICATION
General
Lubrication is vital for successful operation of a compressor. Adequate lubrication of the
proper type in the proper place at the proper time is the key to successful lubrication.
Although lubrication is an ongoing concern throughout the life of the compressor, the initial
package design is very important and deserves special attention.
There are two independent systems for lubricating the compressor; the frame oil system and
the force feed system. The frame oil system is a pressurized circulating system that supplies
a constant pressurized supply of oil to the crankshaft, connecting rods and crossheads. The
force feed system is a low volume high pressure injection system that supplies small quanti-
ties of oil at regular intervals to lubricate the piston rod packings and the piston rings. In
many applications these two systems can use the same lubricant, but in some applications
the lubricants must be different.
Lubrication Functions
Lubrication performs at least six functions in a compressor.
1.
Reduce friction:
A lubricant decreases the resistance to movement between contacting compo-
nents. The lubricant allows the components to slide on an oil film rather than
directly on the component surfaces to reduce friction.
2.
Reduce wear:
A proper lubricating film minimizes contact between sliding components which
reduces wear to increase equipment life expectancy and decrease maintenance
costs.
3.
Remove heat:
Frictional heat is generated between the moving parts and the lubricating film.
Circulating oil allows for heat removal to maintain working tolerances and extend
oil life.
4.
Prevent corrosion:
Keeping air and moisture from the surfaces reduces corrosion to decrease
debris particles, frictional heat, and component wear. Corrosion prevention is
generally provided by additives rather than the base lubricant.
5.
Seal and reduce contaminant buildup:
A liquid lubricant fills small spaces to improve the gas seal on piston rings and
packing rings, and flushes away contaminants from moving parts.
6.
Dampen shock: