BENDIX TU-FLO 400-500-1000 AIR COMPRESSOR manual Operation, Intake and Compression Loaded

FIGURE 5	FIGURE 6
ENGINE LUBRICATED TYPE	SELF-LUBRICATED TYPE

had either die cast aluminum, cast ductile iron, or forged steel rods which were not rifle drilled but were drilled at the top of the rod. The wrist pins and bushings are lubricated by oil dripping from a drip-boss on the piston into a “catch-funnel” at the top of the rod and through the drilled passage to the bushings and pins. (SEE FIG. 7)

PISTON WRIST PIN	WRIST PIN
LOCK WIRE	BUSHING
WRIST PIN	CAST IRON
	PISTON
OIL	STEEL
PASSAGE	CONNECTING
	ROD
	OLD DESIGN
	“CATCH FUNNEL”
WRIST PIN
BUSHING
	DIE CAST
	PISTON
	DIE CAST
	CONNECTING ROD
	NEW DESIGN

FIGURE 7- PISTONS & CONNECTING RODS

A nameplate is attached to the crankcase of all compressors. It shows the piece number, type and serial number (Fig. 8). A nameplate with a black background denotes a new compressor, whereas a nameplate with a red background designates that the compressor is a factory reconditioned unit. All compressors are identified by the piece number which is the number to use when reference is made to a particular compressor. The type and serial number is supplementary information.

FIGURE 8 - COMPRESSOR NAMEPLATE

OPERATION

GENERAL

All compressors run continuously while the engine is running, but actual compression of air is controlled by a governor, which stops or starts the compression of air by loading or unloading the compressor in conjunction with its unloading mechanism. This is done when the air pressure in the system reaches the desired maximum or minimum pressures.

	TO RESERVOIR
DISCHARGE	INLET VALVE
	UNLOADER PLUNGER
VALVE
PISTON	INTAKE
	STRAINER
	TO GOVERNOR
	STROKE
	INTAKE
FIGURE 9

INTAKE AND COMPRESSION (Loaded)

During the down stroke of the piston, a slight vacuum created above the piston causes the inlet valve to move off its seat. Atmospheric air is drawn in through the compressor intake, by the open inlet valve, and on top of the piston (Fig. 9). As the piston starts its upward stroke, the air that was drawn in on the down stroke is being compressed. Now, air pressure on top of the inlet valve plus the force of its spring, returns the inlet valve to its seat. The piston continues the upward stroke and compresses the air sufficiently to overcome the discharge valve spring and unseat the discharge valve. The compressed air then flows by the open discharge valve, into the discharge line and on to the reservoirs (Fig. 10).

	TO RESERVOIR
DISCHARGE	INLET VALVE
	UNLOADER PLUNGER
VALVE
PISTON	INTAKE
	STRAINER
	TO GOVERNOR

STROKE

COMPRESSION

FIGURE 10

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