Bowed rotor prevention system

A gas turbine engine comprising:

• an engine accessory gearbox configured to be coupled to a high pressure spool;
• and
• a bowed rotor prevention system comprising:
• a bowed rotor prevention motor having a motor shaft and a motor bevel gear;
• an air turbine having an output shaft and an output bevel gear;
• a drive shaft operable to mechanically link to the engine accessory gearbox and having an input bevel gear, wherein
• the motor bevel gear, the output bevel gear, and the input bevel gear are coupled at a gear interface such that the bowed rotor prevention motor is operable to drive rotation of the gas turbine through the engine accessory gearbox.

A method of bowed rotor prevention for a gas turbine engine, the method comprising:

• engaging a bowed rotor prevention motor with turbomachinery of the gas turbine engine through an engine accessory gearbox of the gas turbine engine, wherein a motor shaft of the bowed rotor prevention motor interfaces with an air turbine operable to rotate an output shaft mechanically linked to the engine accessory gearbox;
• interfacing an output bevel gear of the output shaft with a motor bevel gear of the motor shaft;
• interfacing an input bevel gear of an air turbine starter drive shaft with the motor bevel gear;
• and
• driving rotation of the turbomachinery of the gas turbine engine by the bowed rotor prevention motor below an engine starting speed until a bowed rotor prevention threshold condition is met.