Fiat 1998 Marea Weekend, Service Manual

Page: 463 / 846

Marea- Marea Weekend
99 range
Auxiliary units
Climate control
50.
Compression mechanism
The contact between the fixed casing and the compressor casing produces a chamber (1) in which the
gas remains imprisoned with the volume tending to gradually decrease as the orbital casing completes its
rotation. As illustrated, the compression chamber is alternately open to supply the gas, closed for trans-
porting it and then again open (at the outlet connector) for the escape of the pressurized gas.
The volume defined by the two scrolls, decreases determining the compression mechanism for the gas
stored. The pressure gradually increases until the gas reaches the centre area where operating pressure is
reached; at this point the gas is released via the outlet connector to the condenser.
The sequence illustrates the different gas compression stages; compression takes place after three com-
plete revolutions of the orbital casing. Naturally, the cycle is continuous, therefore the moment a compres-
sion phase occurs, a gas intake phase is starting as the same time and the previous stage ends with the
release of pressurized gas.
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