PURPOSE: To provide a displacement-ensuring type fluid dealing arrangement in which radial end and side end of the wing panel slide on wall of a cylindrical cavity, long and narrow cavities having sealed rollers fit with wing panels during rotation movement mutually engaged by plural gear wheels that oppositely rotate at the same speed.

CONSTITUTION: The arrangement includes a pair of cylindrical cavities 2, 3 that connects inlet 5 connected with a connection pass 4 to an outlet 6, a wing panel 9 projective from a rotatable boss 10 that rotates around a central axis 8 as the center, and a sealing roller 11 having a rotatable axial cavity 13 that rotates around a central axis 14 as the center. The assembly of the wing plate 9 engaged with a long and narrow concave 12 that rotatably contacts with the boss 10 and has a cylindrical wall of cylindrical cavity in the other side, the boss 10 and the sealing roller 11 is so arranged that it becomes an obstacle wall to the flow of fluid flowing through it. Two wing panels 9, 16 rotate oppositely at the same speed, two assemblies of the elements in pair manner become an obstacle wall to the fluid in the position of between two parts 5, 6.