BENDIX BW2827 사용자 설명서

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OPERATION
The compressor is driven by the vehicle's 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.
AIR INTAKE (LOADED)
Just as the piston begins the down stroke, (a position 
known as top dead center, or TDC), the vacuum created 
in the cylinder bore above the piston causes the inlet reed 
valve to fl ex open.  Atmospheric air fl ows through the open 
inlet valve and fi lls the cylinder bore above the piston.  See 
Figure 4.
AIR COMPRESSION (LOADED)
When the piston reaches the bottom of the stroke, (a 
position known as bottom dead center, or BDC), the inlet 
reed valve closes.  Air above the piston is trapped by the 
closed inlet reed valve and is compressed as the piston 
moves upwards.  When air in the cylinder bore reaches 
a pressure greater than that of the system pressure, the 
discharge reed valves open and allow air to fl ow into the 
discharge line and air brake system.
At the same time air fl ows into the hollow center of the 
unloader piston through an opening in the end of the piston.
FIGURE 3 - BENDIX
®
 BA-921
®
 SMC COMPRESSOR CUT AWAY VIEW
Unloader
Piston
Piston
Discharge
Reed  
Valves (2)
Crankshaft
Connecting Rod
Safety 
Valve
Discharge 
Port
Air 
Inlet 
Port
Coolant
Compressor to 
engine block 
mounting face
Oil drain 
locations
Mounting Face
FIGURE 4 - OPERATION - LOADED (INTAKE)
Piston Moving Down
Air Inlet
Port
Inlet
Valve
Open
Air
Discharge
Port
Discharge
Valve
Closed
Unloader 
Piston 
Down & 
Seated
Valve
Plate
Unloader 
Port
Cooling
Plate