Terrestrial RTG designs featuring disc-shaped thermoelectric modules

A terrestrial radioisotope thermoelectric generator design is described which features the use of two annular or disc-shaped converters at either end of the heat source. The disc-shaped converters were thermally coupled to the heat source via a threaded interface. Pressure loading was accomplished through the use of tapered threads on the heat source and a resilient, thermally conductive member at the cold side (outer diameter) of the annular converter. In this manner, the heat source is supported by the thermoelectric converters at either end of the heat source. An additional feature of this design is the use of a thermal switch which serves to shunt heat from the heat source to the RTG casing when the casing temperature exceeds a predetermined set point