Speed reducing units consisting of mechanical gears are widely used in applications to match high speed prime movers to low speed loads. All aerospace applications of gearboxes require lubrication, maintenance, and overhaul; and are subject to eventually wearing out due to tooth surface wear and gear tooth fatigue. In many cases the requirements for gearbox lubrication, maintenance/overhaul and service life limits are acceptable; but in some extreme applications these requirements become a severe performance limitation. For example, high altitude long endurance missions (HALE) typically operate at an altitude greater than 60,000 feet and stay in flight for durations longer than 24 hours. HALE vehicles need a lightweight, highly efficient solution to operate slow moving propellers maintenance free for an extended period of time in an extreme environment. We are proposing to develop a magnetic gearbox technology that can meet the needs of these extreme applications. A magnetic gearbox has many advantages over a traditional mechanical gearbox. The different rotating components in the magnetic gearbox will never touch so the only lubrication required is in the bearing systems. The magnetic gearbox will be essentially maintenance-free except for periodic bearing lubrication/inspection. Vibrations that do not exceed the pull-out torque of the magnetic teeth do not add measurably to the mechanical stresses in the magnetic gearbox so fatigue issues will be minimal. If the pull-out (maximum) torque is exceeded the magnetic gearbox will simply skip a tooth and re-engage when the overload situation is resolved. In the present research we have demonstrated an experimental magnetic gearbox that achieves much higher specific torque than any previously demonstrated design.
Potential NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) Our magnetic gear technology would work well for NASA electric propulsion vehicles such as LEAPTECH or the Centrifugally Stiffened Rotor Atmospheric Satellite concept being evaluated by NIAC. Lunar and Mars rovers could benefit from this technology in their drivetrains due to the extreme environmental and reliability requirements.
Potential NON-NASA Commercial Applications: (Limit 1500 characters, approximately 150 words) HALE UAVS are an emerging market that many companies have studied to solve various technical problems. Electric propulsion is an attractive approach for these vehicles. Our magnetic gear technology fits well for the propulsion system for these vehicles due to their efficiency, weight, environmental, and longevity requirements.
Technology Taxonomy Mapping: (NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.) Actuators & Motors Atmospheric Propulsion Machines/Mechanical Subsystems
