Patent ID: 8845489
Filing Date: 2014-09-30
Classification: B64C,F01D,F02C,F16H,Y10T

Abstract:
1. A powerplant provided with a drive shaft and at least one engine having an outlet shaft necessarily set into rotation on starting said engine, said drive shaft setting a mechanical system having a main rotor into motion, said engine being a turbine engine having a linked turbine or a piston engine, wherein the powerplant includes a link member provided with a clutch, a declutchable freewheel for linking said outlet shaft mechanically to said drive shaft, and control means, said declutchable freewheel operates either in a disconnected mode during which a driving portion of the declutchable freewheel can under no circumstances set a drivable portion of said declutchable freewheel into motion, or in a freewheel mode during which the driving portion sets the drivable portion into motion as soon as a first speed of rotation of the driving portion becomes greater than a second speed of rotation of the drivable portion, whereas in contrast the driving portion is not setting said drivable portion into rotation when the first speed of rotation is lower than the second speed of rotation; wherein said engine has a first torque level associated with an idling speed and a second torque level associated with a maximum torque output of the engine; wherein said clutch has an operating torque threshold between the first and second torque levels; wherein said control means is configured to operate the powerplant in a starting stage to start the engine after declutching said clutch and declutching said declutchable freewheel so as to disconnect said outlet shaft from said drive shaft such that the main rotor is unpowered; wherein said control means is configured to, in response to the engine torque being greater than the first torque level and less than the operating torque threshold, operate the powerplant in an intermediate stage by clutching said clutch and keeping said declutchable freewheel declutched to connect said outlet shaft to said drive shaft solely via said clutch to rotate the main rotor using the engine; and wherein said control means is configured to, in response to the engine torque being greater than the operating torque threshold, operate the powerplant in a stabilized stage by declutching said clutch and clutching said declutchable freewheel so as to connect said outlet shaft to said drive shaft via said declutchable freewheel to rotate the main rotor using the engine.