Accession Number : ADA298583

Title :   Thermosyphon-Cooled Axial Gap Electric Motors for Ship Propulsion Applications.

Descriptive Note : Doctoral thesis,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF ELECTRICAL ENGINEERING AND COMPU TER SCIENCE

Personal Author(s) : McCoy, Timothy J.

PDF Url : ADA298583

Report Date : JUN 1995

Pagination or Media Count : 132

Abstract : There are many attributes of electric propulsion which make it a desirable technology for use in modern warship designs. However, current motor technology makes electric propulsion noncompetitive from a cost standpoint. The single largest impediment to making electric propulsion more affordable is the size of the propulsion motors. Two technologies aimed at reducing the size of ship propulsion motors are investigated, rotor cooling via radial rotating thermosyphons and the multi-disk axial gap geometry. Size reductions in electric motors are ultimately limited by the ability to remove heat from the windings. Two-phase thermosyphons are considered for cooling the rotor windings of an axial gap motor because they can transfer large amounts of heat with a relatively small temperature difference. Predictions for the heat transfer coefficients of two-phase radially mounted thermosyphons are developed and experimentally evaluated. The multi-disk axial gap geometry significantly reduces both the weight and volume of an electric propulsion motor over conventional radial gap designs. This is accomplished by consolidating several machines together on a single shaft that share a common magnetic circuit. This novel geometry also allows significant reduction in the motor's diameter, giving the ship designer more flexibility in locating the propulsion motors within the ship. into a single design.

Descriptors :   *SHIP MODELS, *ELECTRIC PROPULSION, *ELECTRIC MOTORS, *MARINE PROPULSION, TEMPERATURE, SHIPS, IMPACT, SYNTHESIS, COOLING, COSTS, FEASIBILITY STUDIES, MILITARY APPLICATIONS, SHAFTS(MACHINE ELEMENTS), ROTORS, SYNERGISM, HEAT TRANSFER COEFFICIENTS, MAGNETIC CIRCUITS.

Subject Categories : Electrical and Electronic Equipment
      Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE