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11.1.1 Piston compressors
Piston compressors work by transforming the
rotational movement of the shaft into linear
movement of the pistons.
There are three subfamilies of piston compressors:
g
Crank shaft
g
Swash plate type
g
Wobble plate type
The crank shaft family is more specific to bus
applications.
The swash plate and wobble plate families are
common in light vehicles.
There are two variants, the fixed-cylinder com-
pressors and the variable-cylinder compressors
Fixed-cylinder compressors
The oscillating plate remains at the same angle,
irrespective of the conditions of use.
This variant cannot adjust the cooling power of the
system precisely and only the complete compres-
sor shutdown cycles are possible.
The refrigerant suction occurs in
the compressor suction port.
It is part of the A/C loop Low Pressure
circuit (LP)
The refrigerant discharge occurs in
the compressor discharge port.
It is part of the A/C loop High Pressure
circuit (HP)
11. The components
of the A/C Loop
40
LP
HP
Pistons
Pulley
Oscillating
plate
Suction port
Discharge
port