BENDIX BW1637 Manual Do Utilizador

Página de 40
2
OPERATION
The compressor is driven by the vehicle engine and is 
operating continuously while the engine is running. Actual 
compression of air is controlled by the compressor unload-
ing mechanism and the governor. The governor, which is 
generally mounted on the compressor, maintains the brake 
system air pressure to a preset maximum and minimum 
pressure level.
INTAKE AND COMPRESSION OF AIR (LOADED)
During the down stroke of the piston, a slight vacuum is 
created between the top of the piston and the cylinder head, 
causing the inlet valve to move off its seat and open. (Note: 
The discharge valve remains on its seat.) Atmospheric air 
is drawn through the air strainer and the open inlet valve 
into the cylinder (see Figure 4). As the piston begins its 
upward stroke, the air that was drawn into the cylinder on 
the down stroke is being compressed. Air pressure on the 
inlet valve plus the force of the inlet spring, returns the 
inlet valve to its seat and closes. The piston continues the 
upward stroke and compressed air pushes the discharge 
valve off its seat and air fl ows by the open discharge 
valve, into the discharge line and to the reservoirs (see 
Figure 5). As the piston reaches the top of its stroke and 
starts down, the discharge valve spring and air pressure 
in the discharge line returns the discharge valve to its 
seat. This prevents the compressed air in the  discharge 
AIR INLET
WATER
UNLOADER COVER 
PLATE
AIR DISCHARGE
WATER
AIR
DISCHARGE
GOVERNOR
MOUNTING
PAD
WATER
MANUFACTURED BY BENDIX
TU-FLO 750 COMPRESSOR
BENDIX NO.
SERIAL NO.
FIGURE 2 - MOUNTING CONFIGURATIONS
Various mounting and drive confi gurations, as shown in 
Figure 2, are supplied as required by the vehicle engine 
designs. A nameplate identifying the compressor piece 
number and serial number is attached to the side of the 
crankcase. (Reference Figure 3.)
FIGURE 3 - NAMEPLATE
FIGURE 1 - CYLINDER HEAD
CAT MACK
(MACK STYLE)
DETROIT
DIESEL
MACK
"FOXHEAD"
CUMMINS
MACK
EXTENDED