and an exhaust port which permits exhaust of the fluid out of said primary chamber c said second rotor has a plurality of secondary vanes positioned on a radially outer peripheral surface of said second rotor with spaces between said secondary vanes and said surface defining a plurality of secondary chambers which said secondary vanes and said secondary chambers travel in a secondary track d a first axis of rotation of said first rotor and a second axis of rotation of said second rotor arranged so that said axes of rotation do not intersect said first rotor second rotor first vanes and secondary vanes being arranged so that said first vanes and said secondary vanes intersect at only one location during their rotation and e wherein a first width of said primary track at a point proximal to the point of intersection is greater than a second width of said primary track between each point of intersection and the primary chamber thereby permitting sealing between said primary vanes and said primary track at said second width but not at said first width where both tracks are to be used to compress or expand fluid the track configuration of the invention can be used in both tracks and both sets of vanes can have seals the seal can be disposed within the vane on the vane or in the track the seal can be one seal which is in.