Aircraft turbomachine comprising an electric machine
A turbomachine for an aircraft comprising a stator, a turbine shaft and an electric machine arranged to the rear of the turbine shaft, and comprising an electric machine stator and an electric machine rotor, a rotationally fixed coupling carriage capable of moving in axial translation relative to the electric machine rotor between coupled and uncoupled positions, coupling members which are designed to engage with one another after the coupling carriage has moved from the uncoupled position to the coupled position and to transmit a torque from the turbine shaft to the electric machine rotor when they are engaged, and an elastic return member designed to elastically return the coupling carriage in axial translation to the coupled position.
1. Aircraft turbomachine extending along a longitudinal axis of axial direction and comprising:
a fixed stator,
a turbine shaft extending along the longitudinal axis up to a rear end of the turbomachine and being capable of rotating about the longitudinal axis relative to the stator,
an electric machine arranged at the rear of the turbine shaft and comprising an electric machine stator attached to the stator and an electric machine rotor coaxial with the electric machine stator about an electric machine axis of axial direction and capable of rotating relative to the electric machine stator about said electric machine axis,
a coupling carriage mounted rotationally fixed with the electric machine rotor about the electric machine axis and capable of moving in translation relative to the electric machine rotor in the axial direction between a coupled position and an uncoupled position,
coupling members, one carried by a rear end of the turbine shaft, the other carried by the coupling carriage, the coupling members being designed to engage with one another after the coupling carriage has moved from the uncoupled position to the coupled position and to transmit a torque from the turbine shaft to the electric machine rotor and/or vice versa, when the coupling members are engaged with one another,
an elastic return member mounted between the coupling carriage and the electric machine rotor and designed to elastically return the coupling carriage in translation in the axial direction to the coupled position, and
an actuator designed to drive the coupling carriage in translation from the coupled position to the uncoupled position, the actuator comprising a movable part and a fixed part relative to which the movable part is capable of moving in translation in the axial direction, and wherein the movable part of the actuator is designed to drive the coupling carriage in translation from the coupled position to the uncoupled position, when the movable part itself moves in translation from a first engaged position to a second engaged position, and the movable part of the actuator being designed to move in translation relative to the fixed part from a first disengaged position wherein the movable part and the coupling carriage are free to move relative to one another, to the first engaged position, when the coupling carriage occupies the coupled position.
2. Turbomachine according to claim 1 , wherein the coupling members are dogs.
3. Turbomachine according to claim 1 , wherein the rear end of the turbine shaft carries one of the coupling members by means of an annular support comprising, successively in the axial direction, a first part mounted rotationally fixed with the turbine shaft, a second part carrying said coupling member and a third flexible part connecting the first part to the second part and being capable of allowing a movement of the first part relative to the second part in the axial and radial directions.
4. Turbomachine according to claim 1 , wherein the coupling carriage comprises a carriage part by means of which the coupling carriage is mounted rotationally fixed about the electric machine axis and free in translation in the axial direction with the electric machine rotor, a coupling part carrying the other of the coupling members and a connecting part connecting the carriage part to the coupling part and comprising a first portion that extends axially in the extension of the coupling part towards the carriage part and that forms a tapered flange.
5. Turbomachine according to claim 1 , comprising a lubricated enclosure wherein are housed the bearings supporting the electric machine rotor and first splines arranged in correspondence in the coupling carriage and in the electric machine rotor to drive in rotation the coupling carriage by the electric machine rotor and/or vice versa and to guide in axial translation the coupling carriage relative to the electric machine rotor, and a lubrication circuit comprising an injector designed to inject oil into the lubricated enclosure.
6. Turbomachine according to claim 1 , comprising locking members, one carried by the electric machine rotor, the other carried by the coupling carriage, the locking members being designed to engage with one another after the coupling carriage has moved in translation relative to the electric machine rotor from the coupled position to the uncoupled position and to lock the translational movement of the coupling carriage relative to the electric machine rotor from the uncoupled position to the coupled position, when the coupling carriage occupies the uncoupled position.
7. Turbomachine according to claim 6 , wherein the movable part of the actuator is designed to move in translation relative to the fixed part from the second engaged position to a second disengaged position wherein the movable part and the coupling carriage are free to move relative to one another, when the coupling carriage is locked in uncoupled position by the locking members.