A system for the construction of compressors and rotary engines having two rotors with one, or more displacers per rotor to create between the displacers two or more chambers. The chambers vary in volume according to the degree of separation between the piston caused by the varying and alternatively opposite velocities between the two rotors. This speed variation can be produced a length variation of the radius in which a regular and uniform rotary motion is transmitted or received transforming it into an oscillating motion. The distance between the displacers is modified by placing the drive mechanism on the slide rails and moving it by a spindle, a hydraulic piston or geared system. The other dynamically modifies the beginning of the suction and compression phases preventing sealing of the displacers in certain segments of the suction-compression chamber, to create an opening, allowing passage of fluids and preventing its displacement.