Bendix Commercial Vehicle Systems BA-922 COMPRESSOR - Manual

FIGURE 1 - BA-922 ® COMPRESSOR
DESCRIPTION
The function of the air compressor is to provide and
maintain air under pressure to operate devices in the
air brake systems. The Bendix ® BA-922 ® compressor
is a two cylinder reciprocating compressor with a rated
displacement of 31.6 cubic feet per minute at 1250 RPM.
The compressor consists of a water cooled cylinder head,
cooling plate, valve plate assembly and an integral air
cooled crankcase and cylinder block. The cast aluminum
cylinder head contains the required air and water ports as
well as two unloader pistons. The cast aluminum cooling
plate provides added cooling to, and is located between,
the cylinder head and valve plate assemblies. The valve
plate assembly consists of laminated brazed steel plates
which incorporate various valve openings and channels
for conducting air and engine coolant into and out of the
cylinder head.
The discharge valves are part of the valve plate assembly.
The cylinder head, with the cooling and valve plates
comprise a complete cylinder head assembly.
The cast iron crankcase and cylinder block assembly,
houses the pistons, connecting rods, crankshaft and related
bearings.
While not all compressors and charging systems are
equipped with an optional discharge line safety valve,
this component is recommended. The discharge line
safety valve is installed in the cylinder head or close to
the compressor discharge port and protects against over
pressurizing the compressor in the event of a discharge
line freeze up or blockage.
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
governor.
FIGURE 2 - BA-922 ® COMPRESSOR (CUT-AWAY)
Unloader (2)
Cooling
Plate
Piston Rod
Delivery
Port
Piston
Air
Intake
Unloader
Port
Discharge
Reed
Valves
Crankshaft
SD-01-700
BENDIX ® BA-922 ® COMPRESSOR
Safety
Valve
Valve Plate
Assembly
Crankcase and
Cylinder Block
Cylinder
Head