SBIR-STTR Award

Four bearingless, shaft mounted generators with outputs of 10, 100, 500 and 1000 watts of 12-15 v dc will be designed and computer modeled to be driven by model airplane size reciprocating engines. Design combinations of ironless disk and iron lamination cylindrical generators using rare earth and ceramic permanent magnets will be modeled for reliability with the lowest weight at the highest efficiency related to estimated material cost of production models. Proprietary high performance generator design software previously written by the pi (principle investigator) will be modified to optimize the design and operation of these generators. A number of high performance generators, including a 500 watt generator driven by a 2cc engine have been designed, built and tested for industrial applications with the assistance of this software. As generator weight is reduced, efficiency drops and more fuel is required per flight mission. An operating model will be written to optimize total mission weight and maintainability. A 10 watt prototype (or as specified) will be built and tested to compare performance with the computer designed model for rpm vs. output, efficiency and weight. Anticipated benefits/potential commercial applications - the lightweight generator will provide on-board electrical power to enable long duration flights of very small aircraft. Uses include serveilance, aerial mapping, expendable flights into hazardous situations and low cost relay platforms. The miniature engine driven generator provides the basis for very small portable generator sets. A quart size gen set would produce 500 watts for emergency lighting or remote car or truck starting in the winter.

The design software written and the experience gained in building the 200 watt, 4.5 ounce model airplane engine permanent magnet alternator in Phase I and the duel voltage, post Phase I, 7.5 kW alternator will be used as the basis in Phase II to further develop alternators for four different applications, two for sub-scale aircraft and two for commercial bus and truck applications. Four methods of pm alternator voltage regulation will be further developed. Preliminary patent searches indicate three of these methods may be proprietary. Applicable safety regulations, industry standards and field maintenance requirements will be integrated into the alternator and control designs with an emphasis on simultaneously increasing reliability and reducing cost in both material and labor for future production. A limited quantity of pm alternators and controls for each application will be manufactured and field tested under actual use conditions. Data will be gathered on performance, reliability and maintenance required. Anticipated

Benefits:
Miniature PM alternators will be field tested and ready for production for DoD applications and hobbiest use. The 7.5 kq pm duel voltage vehicle engine driven alternator will meet all applicable regulation requirements and be producible in commercial quantities. Applications include ambulances, instrumentation vans and non-CFC hermetically sealed mobile refrigeration and air conditioning. A 10 watt prototype (or as specified) will be built and tested to compare performance with the computer designed model for rpm vs. output, efficiency and weight. Anticipated benefits/potential commercial applications - The lightweight generator will provide on-board electrical power to enable long duration flights of very smallaircraft. Uses include surveillance, aerial mapping, expendable flights into hazardous situations and low cost relay platforms. The miniature engine driven generator provides the basis for very small portable generator sets. A quart size gen set would produce 500 watts for emergency lighting or remote car or truck starting in the winter.