Patent ID: 7549851

Claim:
A rotary fluid machine comprising: a first rotation mechanism and a second rotation mechanism, each of which includes a cylinder having an annular cylinder chamber; an annular piston disposed in the cylinder chamber to be eccentric to the cylinder, the annular piston dividing the cylinder chamber into an outer working chamber and an inner working chamber; and a blade arranged in the cylinder chamber to divide each of the working chambers into a high pressure region and a low pressure region, the piston and the cylinder serving as co-operating parts and any one of the piston and the cylinder being stationary and the other being rotatable about the stationary co-operating part, the first rotation mechanism and the second rotation mechanism being adjacent to each other with a partition plate sandwiched therebetween, the two moving co-operating parts or the two stationary co-operating parts of the first rotation mechanism and the second rotation mechanism being arranged such that one of the co-operating parts is provided at one side of the partition plate and the other is provided at the other side of the partition plate, and the first rotation mechanism and the second rotation mechanism being configured to rotate with a 90° phase difference from each other.