Low Thermal Conductance Torque Tube System

Period of Performance: 04/13/2000 - 10/31/2000


Phase 1 SBIR

Recipient Firm

Foster-miller, Inc.
350 Second Ave.
Waltham, MA 02451
Principal Investigator


The U.S. Navy and private industry are investing heavily in several ship electric drive systems including the High Temperature Superconducting (HTS) ac synchronous motor system, the Superconducting Homopolar motor and the Permanent Magnet (PM) motor. Composite drive shafts with optimized high torque end fittings hold promise for significant weight reduction. In the HTS ac synchronous motor these shafts are necessary to minimize heat leak to the rotating HTS coils Foster-Miller proposes to develop a low thermal conductance torque tube system which will provide minimum heat leak for the HTS ac synchronous motor application while also bringing significant value to the other ship electric drive options. The proposed approach employs Foster-Miller's Ultrasonic Tape Lamination (UTL) technology and tape winding. UTL enables on-the-fly, net thickness placement of the prepreg and the potential for non-autoclave curing. Several innovative designs in material selection, fiber architecture and end fitting integration are presented in detail in the proposal.Foster-Miller has teamed with American Superconductor and Alliant TechSystems to bring all of the expertise necessary to address this complex problem. In this program, the team will evaluate options, develop, analyze and design a low thermal conductance torque tube system and demonstrate key aspects of its fabrication. (P-00421) The proposed program will explore an advanced composite ship drive shaft system. This will support the HTS ac synchronous motor as well as several other electric drive systems for both Navy and commercial applications. The technology development is also a major asset for composite tube development for deep water oil drilling, civil structures and other applications. Beyond tubes, the integration of UTL and fiber placement has the potential to provide a dramatic advancement in composites manufacturing through on-the-fly debulking and curing.