HVAC Rotating blade rotary compressors
The rotating blade rotary compressor has its roller centered on a shaft that is eccentric to the center of the cylinder. Two spring-loaded roller blades are mounted 180° apart. They sweep the sides of the cylinder. The roller is mounted so that it touches the cylinder at a point between the intake and the discharge ports. The roller rotates. In rotating, it pulls
the vapor into the cylinder through the intake port. Here, the vapor is trapped in the space between the cylinder wall, the blade, and the point of contact between the roller and the cylinder. As the next blade passes the contact point, the vapor is compressed. The space or the vapor becomes smaller and smaller as the blade rotates.
Once the vapor has reached the pressure determined by the compressor manufacturer, it exits through the discharge port to the condenser.
On this type of rotating blade rotary compressor the seals on the blades present a particular problem. There also are lubrication problems. However, a number of rotary compressors are still in operation in home refrigerators.
Some manufacturers make rotary blade compressors for commercial applications. They are used primarily with ammonia. Thus, there is no copper or copper alloy tubing or parts. Most of the ammonia tubing and working metal is stainless steel.