Scroll compressors have basically one moving part on the inside of the engine. The internal “scroll” will actually move in an elliptical style pattern to produce the compressed air. Internally you have a stator which has an opposite of itself moving in opposing direction. These two rotate inside and are constantly turning, pulling air in and compressing it as it goes around.
As the scroll continues to move to the center and out there is no contact between the two pieces and it moves in one direction making it 100 percent efficient.
Another reason scrolls are so much better than a piston style compressor is because it only has to move in one direction with no “cycles” like piston compressors have. Having such a close tolerance on the inside of the motor makes it move efficiently since these pieces never touch. Again there is only a small couple thousands tolerance between the two. Eastwood uses a premium synthetic oil inside here which takes up that difference and creates the airtight seal here. Scroll compressors will last just as long if not longer than piston styles since they are designed to run constantly, can spin up to about 3000 rpm, and have such a long pump life so you can let them run all day long.
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