BENDIX SD-01-700 Manuale Utente

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 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.

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.

Unloader (2)

Cooling

Plate

Piston Rod

Delivery

Port

Piston

Air

Intake

Unloader 

Port

Discharge

Reed

Valves

Crankshaft

Safety

Valve

Valve Plate 

Assembly

Crankcase and 

Cylinder Block

Cylinder

Head