Patent ID: 8097972

Claim:
A gas turbine engine having a compressor section and a turbine section, comprising: a first shaft being one of a main shaft concentrically mounted to at least one turbine rotor of the turbine section and a tower shaft directly driven by the main shaft and extending generally radially therefrom, the first shaft having a portion located within the gas turbine engine, said portion of said first shaft having a reduced diameter relative to a remainder of said first shaft, the portion having said reduced diameter forming at least one circumferentially-extending recess in the first shaft; an electrical machine assembly having a rotor and a stator, the rotor including permanent magnets secured to an outer surface of the reduced diameter portion of the first shaft such that the permanent magnets of said rotor are received within said circumferential recess, the stator being disposed adjacent an outer periphery of the rotor and including at least one field winding, the rotor and the stator cooperating in use to provide a magnetic circuit for conducting magnetic flux around the at least one field winding; and an electrical connection between the at least one winding and at least one of a power source and a power distribution system.