Demonstration of a Lightweight Magnesium Diesel Generator

The original objective of this Marine Corps-funded development effort was to develop a prototype 1 kW diesel generator that weighed less than 50 pounds. Mainstream's first prototype easily satisfied this requirement early in the development. A second-generation prototype was then developed with reduced engine block size and weight and increased power output. Extensive life testing of the second-generation design resulted in the formulation of a third-generation prototype that substituted magnesium for aluminum in the engine block. Magnesium, which is stronger and lighter than aluminum, reduced the engine block weight an additional 33%.

The resulting patent-pending diesel engine generator configuration has a shaft output of 2.8 kW and can generate more than 2.24 kW electrical power (80% alternator efficiency). The first, second and third generation total diesel generator weights are 42.1, 40.7 and 36.5 lbs, respectively. Having exceeded the Marine Corps operational requirements, extensive life testing of the third-generation engine was performed and successfully completed. Follow-on efforts focused on demonstrating the reliability and maintainability of the diesel engine, optimizing the integrated alternator, fabricating a reduced-cost production version, and successful field-testing by DOD users.