FATHOM5 CORP — Department of Defense SBIR Phase I: N231-053

Description

Fathom5 proposes to insert a Simplified Parallel Eccentric (SPE) drive train in between the existing EMA electric motor and the linear screw. The SPE is a novel, patented, high-torque compact drive train that is part of Fathom5’s Tesar Lift™ developmental product line of electromagnetic actuators.  The SPE input will be outfitted with a bull gear driven by an idler/pinion that is connected to a battery powered lower-torque electric motor, hereafter referred to as the lowering motor.  The lowering motor engages the bull gear. The battery system will be charged while the JBD is in nominal operations. In the event of a loss of primary and back-up EMA power, the Lowering Motor can be remotely commanded to lower each of the JBD panels. The lowering motor and bull-gear assembly will not be sized to conduct efficient raising operations but will be able to directly back drive the SPE geartrain from its input. This allows the lowering effort to be reverse driving (rather than back driving) the linear screw, removing a significant amount of the lowering resistance. This has the added effect of placing a reduction ratio in between the EMA motor and linear screw, providing more mechanical advantage to the existing EMA assembly and lowering its overall current requirements during door acceleration and deceleration jerks. The expected operation time under the lowering motor is estimated to be one minute or less per panel. Total emergency lowering time would depend on the number of panels that could be simultaneously stowed as determined by the result of this Phase I effort.  The SPE is a novel eccentric gearbox allowing high volumetric torque density. The reduction in the number of parts compared to traditional eccentric reducers allows the tailoring of strength and reliability properties depending on application with a focus on high torque industrial applications. Fathom5's SPE differs from existing eccentric gearboxes by using spur tooth shapes instead of cycloidal discs, which increases load capacity and durability.