Ahermetic compressor is a direct compressor—a direct-connected motor compressor assembly enclosed within a steel housing. It is designed to pump low-pressure refrigerant gas to a higher pressure.
A hermetic container is one that is tightly sealed so no gas or liquid can enter or escape. Welding seals the container.
Tecumseh hermetic compressors have a low-pressure shell, or housing. This means that the interior of the compressor housing is subject only to suction pressure. It is not subject to the discharge created by the piston stroke. This point is emphasized to stress the hazard of introducing highpressure gas into the compressor shell at pressures above 150 psig.
The major internal parts of a hermetic compressor are shown in Fig. 9-10. The suction is drawing into the compressor shell then to and through the electric motor that provides power to the crankshaft. The crankshaft revolves in its bearings, driving the piston or pistons in the cylinder or cylinders. The crankshaft is designed to carry oil from the oil pump in the bottom of the compressor to all bearing surfaces. Refrigerant gas surrounds the compressor crankcase and the motor as it is drawn through the compressor shell and into the cylinder or cylinders, through the suction muffler and suction valves. The gas is compressed by the moving piston and is released through the discharge valves, discharge muffler, and compressor discharge tube.