Auxiliary power unit comprising a gas generator in direct-drive connection with an electric generator and an accessory gearbox

An auxiliary power unit, comprising:

• a gas generator comprising successively along a same axis, an exhaust nozzle, a gas turbine, a combustion chamber section and a main air compressor driven in rotation by said gas turbine;
• an electric generator including an input shaft connected to an output shaft of the gas generator, the electric generator being coupled to the gas generator upstream of the main air compressor, on a side opposite to the gas turbine;
• and
• an accessory gearbox directly connected to a rotor shaft of the electric generator, the gearbox having a casing with radial dimensions smaller than or equal to radial dimensions of the electric generator, wherein the electric generator is mounted between the gas generator and said accessory gearbox,
• wherein the auxiliary power unit is configured to provide energy to an aircraft, and
• wherein the gas generator comprises a load compressor driven in rotation by the gas turbine and mounted axially between the main air compressor and the electric generator.