User's Manual

2
DETROIT DIESEL CATERPILLAR
FIGURE 2 - TYPICAL COMPRESSOR DRIVE FLANGES
FIGURE 3 - DURAFLO 596
™
AIR COMPRESSOR UNLOADER SYSTEM
DURAFLO
™
596
COMPRESSOR
SUPPLY
RESERVOIR
AIR
DRYER
SYNCHRO VALVE
GOVERNOR
body assembly is secured to the cylinder head assembly
using two cap screws and the cylinder head is secured to
the cylinder block with six cap screws. The cylinder head,
with the valve body halves, comprise a complete cylinder
head assembly.
The cast iron crankcase and cylinder block assembly,
houses the pistons, connecting rods, crankshaft and related
bearings. Unloader plungers and related seals and springs
are contained in bores in the cylinder block. Sliding inlet
valves and their pivot arms are sandwiched between the
cylinder block and valve body assembly.
The DuraFlo
596
™
compressor incorporates an unloader
system that features an energy saving system or ESS
which reduces compressor power consumption by
approximately 80% in the unloaded mode. The ESS also
reduces compressor oil consumption (oil passing) when
the compressor is in the unloaded mode.
A nameplate identifying the compressor piece number and
serial number is attached to the end of the cylinder block
opposite the drive end.
OPERATION
The compressor is driven by the vehicle engine and
functions continuously while the engine is in operation.
Actual compression of air is controlled by the compressor
unloading mechanism operating in conjunction with a remote
mounted governor and synchro valve. Unlike the Tu-Flo
®
compressor series, the DuraFlo 596
™
compressor
requires the addition of a synchro valve to assure proper
operation and service life. The governor and synchro valve
combination maintains brake system air pressure between
a preset maximum and minimum pressure level. Refer to
Figure 3.
The compressor has a built in unloading and ESS or
Energy Saving System.
AIR INTAKE (LOADED)
The piston strokes are 180 degrees opposed. As one
piston is on an up stroke the opposing piston is on a down
stroke. During the piston down stroke, a vacuum is created
in the cylinder and ESS chamber within the cylinder head.
The vacuum causes the inlet check valve and sliding inlet
valve to fl ex open. Atmospheric air fl ows through the open
inlet check valve into and through the ESS chamber to the
sliding inlet valve. Air fl owing past the sliding inlet valve fi lls
the cylinder above the piston. See Figures 4 & 7.
TO
COMPRESSOR
UNLOADERS
SUPPLY
CONTROL
DELIVERY
FROM
SUPPLY
RESERVOIR
GOVERNOR
(110 CUT-IN 130
CUTOUT)
TO AIR
DRYER
SYNCHRO
VALVE
FROM
SUPPLY
RESERVOIR