VOLUMETRIC ROTARY MACHINE

The fluid-flow displacement rotary machine can be used as an engine, e.g., a diesel engine or internal combustion engine, as well as a pump, compressor, turbine, also in measuring equipment such as flow-meters and dosimeters; it comprises a stator and a drive rotor between which at least one chamber-defining space is formed, subdivided into working chambers by the driven rotors. The chamber-defining space is defined by the surface similar to the surface of a revolution body formed by rotating the stator together with the driven rotor about the axis of the drive rotor, with simultaneous rotation of the driven rotor around its own axis. At least one recess is made along the driven rotor perimeter, having a depth at which the bottom of the recess is disposed under the stator effective area in any position assumed by the rotor. The invention makes it possible to extend technological and performance capabilities and to increase the efficiency factor and specific power rating of the machine. The fluid-flow displacement rotary machine comprises no ballast volume (that is, the volume of the structural members of the machine depends only on strength of materials) and is less sensitive to abrasive impurities in the working fluid. High specific output at the same rotational speed thereof compared with other rotor-type machines renders the machine efficiently applicable in aircraft engineering and in the automotive industry, especially for disposing the engines of such type in the wheels of a motor vehicle.