how does cummings air commpressor work?

Answer 1

Are you referring to the Air Compressor for the brake supply for a CUMMINS engine?
If so, they work pretty much like an engine, except that there is no POWER stroke, and the valves are REED valves rather than stem style.
When the piston is driven down by the accessory drive to the compressor crankshaft, it causes vacuum in the chamber, which causes the intake reed to open.
When the piston reaches the bottom of the stroke, the intake reed is allowed to close, and the piston begins its upward travel, and the pressure developed causes the exhaust reed to unseat, and the compressed air is driven into the system to be stored in the reservoir tanks.
When the air pressure reaches approximately 120 PSI, that pressure causes the governor to un-load, and the air compressor ceases to compress the air, but it continues operation mechanically.

Hope this clears things up!!

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