BACKGROUND

An aircraft engine, for example a gas turbine engine, is engaged in regular operation to an air turbine starter. The internal components of both the gas turbine engine and the air turbine starter spin together and can each include gearboxes allowing for step down or step up ratios between consecutive parts. To prevent back drive, an overrunning clutch is placed between the air turbine starter output shaft and the air turbine starter gearbox section. Back drive events can occur with an overrunning clutch failure in the engaged position, when the engine drives the output shaft of the air turbine starter resulting in over spinning a turbine rotor in the air turbine starter. In a back drive event, it can be desirable to decouple the air turbine starter from the gas turbine engine.

BRIEF DESCRIPTION

In one aspect, the present disclosure relates to an air turbine starter for starting an engine, comprising a housing defining an inlet, an outlet, and a flow path extending between the inlet and the outlet for communicating a flow of gas there through, a turbine member journaled within the housing and disposed within the flow path for rotatably extracting mechanical power from the flow of gas, a gear train drivingly coupled with the turbine member, a drive shaft operably coupled with the gear train and having ramped teeth on its output end, and a decoupler, comprising an output shaft having a first end with mating ramped teeth that are selectively operably coupled to the drive shaft and a second end configured to be operably coupled to and rotate with the engine, the ramped teeth allow for driving torque transfer from the drive shaft to the output shaft and the ramped teeth slide on each other when back driving torque is transmitted such that the output shaft is moved away from the drive shaft, and a connector having a body with a first and second end and extending between the output shaft and the drive shaft a magnetic coupling selectively linking the drive shaft to the output shaft via the connector, when driving torque is transmitted the connector is magnetically linked to one of the output shaft or the drive shaft via the magnetic coupling and when back driving torque is transmitted the connector is moved away from at least a portion of the magnetic coupling.

In another aspect the present disclosure relates to an air turbine starter for starting an engine, comprising a housing defining an inlet, an outlet, and a flow path extending between the inlet and the outlet for communicating a flow of gas there through, a turbine member journaled within the housing and disposed within the flow path for rotatably extracting mechanical power from the flow of gas, a gear train drivingly coupled with the turbine member, a drive shaft operably coupled with the gear train and having an output end, an intermediate connector having a body with a first end operably coupled to the output end of the drive shaft and a second end, opposite the first end, having ramped teeth, an output shaft having a first end with mating ramped teeth that are selectively operably coupled to the intermediate connector and a second end configured to be operably coupled to and rotate with the engine, the ramped teeth allow for driving torque transfer from the intermediate connector to the output shaft and the ramped teeth slide on each other when back driving torque is transmitted such that the intermediate connector is moved away from the output shaft, a connector having a first end coupled to the intermediate connector and a second end selectively operably coupled to the output shaft; and a magnetic coupling dipole mounted within the drive shaft and configured to magnetically couple with at least one of the intermediate connector or the connector.

