period one
Compressor Types
notes
+HUPHWLF&RPSUHVVRU
KRXVLQJ
PRWRU
FRPSUHVVRU 
SLVWRQ
Figure 25
A hermetic compressor, on the other hand, seals the motor within the compressor housing. This motor is cooled by the refrigerant, either by refrigerant vapor that is being drawn into the compressor from the suction line or by liquid refrigerant that is being drawn from the liquid line. The heat from the motor is then rejected by the condenser.
Hermetic compressors eliminate the need for the shaft couplings and external shaft seals that are associated with open motors. The coupling needs precise alignment, and these seals are a prime source of oil and refrigerant leaks. On the other hand, if a motor burns out, a system with a hermetic compressor will require thorough cleaning, while a system with an open compressor will not.
6HPLKHUPHWLF&RPSUHVVRU
SLVWRQ
PRWRU 
FRPSUHVVRU FUDQNVKDIW
KRXVLQJ 
Figure 26
Similarly, the motor for a semihermetic compressor is also contained within the compressor housing and is cooled by the refrigerant. The term “semihermetic” means that the sealed housing is designed to be opened to repair or overhaul the compressor or motor.
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