Generator for electrically powered refrigeration unit

An all electric transport refrigeration system comprises a compressor 116 and drive motor 118. The motor 118 is driven by a single on-board engine 350 driven generator 300 that is of the axial air gap design type. The incorporation of an axial air gap type generator in the transport refrigeration system results in a system that meets space limitations while at the same time achieves the desired level of power output. This is due to the inherently slim profile of the axial air gap type generator which also promotes greater accessibility and ease of service to generator elements. Various arrangements of generator rotor and stator are disclosed.