Turbomachine having a device for automatically detecting ferromagnetic particles in an oil enclosure

1. A turbomachine having a longitudinal axis, the turbomachine comprising an annular rotor centered on the longitudinal axis of the turbomachine, an annular stator disposed coaxially around the rotor, at least one ball bearing disposed on the rotor and rotatably supporting said stator, the inside of the rotor defining part of an oil enclosure for cooling and lubricating the balls of the bearing, and an electricity generator having a secondary magnetic circuit secured to the stator and a primary magnetic circuit constrained to rotate with the rotor, the turbomachine further including a detector device for automatically detecting ferromagnetic particles in the oil enclosure, said detector device being powered electrically by electromagnetic induction,

wherein the detector device comprises;

a pair of electrodes disposed on the inside annular face of the rotor; and

a secondary magnetic circuit secured to the rotor, said circuit being excited by the magnetic field created by the secondary magnetic circuit of the electricity generator of the turbomachine so as to apply a voltage between the electrodes.

2. A turbomachine according to claim 1 , wherein each electrode comprising a metal film and a plurality of substantially parallel metal tracks, each of the electrodes being interleaved with between the tracks of the other electrode; wherein when ferromagnetic particles are received between the tracks of the electrodes, an electrical signal is generated between said electrodes; and

wherein a detector further comprises a detector for detecting the intensity of the electrical signal generated between the electrodes, the intensity of said electrical signal being a function of the ferromagnetic particles present in the oil enclosure.

3. A turbomachine according to claim 2 , wherein the detector device further includes a radio transmitter connected to the detector in order to transmit a radio signal to a full authority digital engine controller of the turbomachine, which signal is a function of the density of ferromagnetic particles present in the oil enclosure.

4. A turbomachine according to claim 2 , wherein the secondary magnetic circuit of the detector device is constituted by a coil of conductor wire.

5. A turbomachine according to claim 1 , wherein the metal film of each electrode of the detector device extends substantially along the longitudinal axis of the turbomachine, and the metal tracks of each electrode extend in a direction that is substantially transverse relative to said longitudinal axis of the turbomachine.

6. A turbomachine according to claim 2 , wherein the metal tracks of each electrode of the detector device extends substantially along the longitudinal axis of the turbomachine, and the metal film of each electrode extends in a direction that is substantially transverse relative to said longitudinal axis of the turbomachine.

7. A turbomachine according to claim 1 , wherein the secondary magnetic circuit of the electricity generator is constituted by a coil wound on an inner annular face of the stator, and the primary magnetic circuit of the electricity generator is constituted by at least one magnet disposed on an outer annular face of the rotor.

8. A turbomachine according to claim 7 , wherein the coil and the magnet(s) of the electricity generator are isolated from the oil enclosure by annular sealing devices secured to the stator.

9. A turbomachine according to claim 1 , wherein the rotor and the and the stator belong to the high-pressure body of the turbomachine.