Rotary compressor
In a compressor , a gaseous fluid is sucked in at low pressure and compressed to a higher pressure. Compressors with rotating pistons are called rotary or circulating compressors. Rotary compressors are mainly used in the small refrigeration area for refrigerators , freezers and room air conditioners.
A distinction is made between open, semi-hermetic and hermetic versions of the compressors. The functioning of the compressor is not decisive here. The designation only indicates the relationship between compressor and drive motor.
How the rotary compressor works (rotary piston compressor)
A rotary compressor essentially consists of four components - the housing, an eccentrically mounted rotor and a separating slide that sits inside the housing together with a helical spring . The function of the spring is to always press the slide gate against the rotor.
The rotor pushes the compressed gas into the hot gas line above the slide valve. Gas that is sucked in flows into the housing below the slide. The suction side is sealed from the pressure side by the separating slide, which moves back and forth with the cycle of the rotating rotor.
Multi-chamber rotary compressor
A variant of the rotary compressor is the multi-chamber rotary compressor - also known as a rotary or cell compressor. The axis of the rotor is again positioned eccentrically in the direction of the pressure port, but the rotor itself sits concentrically on this type of compressor. Several slides are used in the rotor, which are pressed against the housing wall by centrifugal force or via springs. These slide valves form chambers, the volume of which changes as the rotor rotates.
The chamber volume is greatest on the suction side; if you turn it further towards the pressure side, it becomes smaller, thereby compressing the gaseous fluid contained and ejecting it through the pressure port. On the other hand, an increasing negative pressure is generated on the opposite chamber, which ensures the supply of gas from the intake port.
A small residual volume, which is enclosed between the rotating piston and the housing, expands again after the gas is expelled and thus reduces the suction volume. This reduction in the delivery rate depends on the compression ratio.