US Patent 7567418 Thermal isolating torque tube

A torque tube assembly for transmitting rotational force from a first end to a second end includes a number n of concentric elongate torque tubes, where n is an odd integer greater than or equal to three. The concentric elongate torque tubes are connected for co-rotation. A serpentine thermal conduction path is defined between the first end of the torque tube assembly and the second end of the torque tube assembly, and includes at least a portion of each of the concentric elongate torque tubes.