Aircraft starter generator

1. A starter generator for use with an engine, the engine having a compressor for compressing air, a combustor for combusting fuel with the air compressed by the compressor, first and second turbines adapted to be rotated by impingements of compressed combustion gases from the combustor, a first rotating shaft drivingly connected with the compressor and the first turbine so that it rotates with the compressor and the first turbine, and a second rotating shaft drivingly connected with the second turbine so that it rotates with the second turbine, comprising:

an electric rotating machine having a rotating shaft, the rotating machine being designed to carry on two reverse operations—motor and generator;

a first clutch connected between the rotating machine and the first rotating shaft for transmitting rotations of the rotating machine to the first rotating shaft;

a second clutch connected between the rotating machine and the second rotating shaft for transmitting rotations of the second rotating shaft to the rotating machine;

a continuously variable transmission for changing the number of rotations transmitted from the second rotating shaft to the rotating machine; and

a control designed to carry out a first mode in which the rotating machine is supplied with electric power to rotate the rotating shaft and thereby rotations of the rotating shaft are transmitted through the first clutch to the first rotating shaft and a second mode in which, following the first mode, the number of rotations of the rotating shaft of the rotating machine is kept constant by controlling a transmission ratio of the continuously variable transmission.

2. The starter generator of claim 1 , wherein the control is so designed that it disconnects the first rotating shaft from the rotating machine when the number of rotations of the first rotating shaft reaches a first rotation number and controls the continuously variable transmission to cause the rotations of the second rotating shaft to be transmitted to the rotating shaft of the rotating machine when the rotation number of the first rotating shaft reaches a second rotation number which is greater than the first rotation number.

3. The starter generator of claim 1 , wherein one end of the rotating shaft of the rotating machine is connected to the first clutch through a first gear train and the other end of the rotating shaft of the rotating machine is connected to the second clutch through the continuously variable transmission.

4. The starter generator of claim 1 , wherein the second clutch is connected between the continuously variable transmission and the second rotating shaft.

5. The starter generator of claim 1 , wherein the second clutch is connected between the continuously variable transmission and a second gear train.

6. The starter generator of claim 3 , further comprising

a housing accommodating the rotating machine, the continuously variable transmission, the first clutch, the second clutch, the first gear train, and a second gear train; and

a gear box accommodating a third gear train connected to the first and second rotating shafts.

7. The starter generator of claim 3 , further comprising

a gear box accommodating the first clutch, the second clutch, the first gear train, a second gear train, and a third gear train connected to the first and second rotating shafts;

a first housing accommodating the rotating machine; and

a second housing accommodating the continuously variable transmission, the first and second housings being connected to the gear box.

8. The starter generator of claim 1 , wherein the first clutch is a one-way clutch.

9. The starter generator of claim 1 , wherein the second clutch is a one-way clutch.