Patent ID: 8701380
Filing Date: 2014-04-22
Classification: B64C,B64D,F02K,Y02T

Abstract:
1. A turbine engine comprising: a free power turbine including a first rotor and a second rotor which are contrarotating about an axis of the turbine engine; a first downstream external impeller and a second upstream external impeller disposed downstream of the free power turbine, the first and second impellers being nonstreamlined, coaxial and contrarotating about the axis of the turbine engine, the first downstream impeller being retractable so as to reduce its diameter; a mechanism for actuating the first downstream impeller in a retracted position with a braking device which brakes rotation of the first downstream impeller and an actuating device which actuates blades of the first downstream impeller into the retracted position when the braking device is actuated; and an epicyclic gear train which drives the first and second impellers, the gear train including a sun gear comprising a gearwheel with external teeth and supported by a sun-gear shaft, a planet gear comprising a gearwheel with external teeth meshing with the sun gear and supported by a planet-gear shaft, a planet carrier which supports the planet gear in a rotary manner and includes a planet-carrier shaft, and a ring gear comprising a gearwheel with internal teeth meshing with the planet gear and supported by first and second ring-gear shafts, wherein the sun-gear shaft is connected to the first rotor, the planet-carrier shaft is secured to the first downstream impeller, the first ring-gear shaft is secured to the second upstream impeller, and the second ring-gear shaft is connected to the second rotor, and wherein the braking device is arranged to brake rotation of the planet-carrier shaft.