Utility electromechanical geared rotary actuators (EGRAs) for cargo require rugged, reliable, and robust design elements to meet the lifetime demands for the application and environment.
A modern military aircraft required an EGRA as part of a Cargo Restraining System (CRS). The EGRA not only locks cargo pallets into position but also responds to timing commands to support airdrop operations. The EGRA must be extremely reliable and rugged, a reported problem with the original design. Several big companies had failed attempting to provide a solution and the need was urgent. The aircraft manufacturer was forced to delay tests of the CRS and loading system, which cause financial strain on the CRS provider and a blemish to the overall program. With only 12 months remaining to aircraft certification, Ingenium Aerospace was contacted by the CRS provider to create a new design to meet the torque, operating speed, durability, and reliability demands for this application.
The application needed four pairs of rotary EGRAs to package within the tight envelope constraint created by a floor-mounted attachment flange that is part of the CRS. In addition to the ability to survive repeated mechanical shock and high impact loads generated by the pallet movement during aircraft loading operations, Ingenium’s EGRAs had to retain the factory set precision alignment or “clocking.” Lost alignment in any one of the EGRAs during an airdrop could result in a jammed pallet, causing imbalance in the aircraft’s center of gravity and producing an improper delivery of payload. Ingenium Aerospace designed all features of the EGRA and test equipment needed to produce the units in full rate production volume. The custom integral gear set and DC motor assembly within the EGRA provides ample torque and speed needed to quickly lock and unlock the CRS. The custom clutch and manual override feature also add to the robust design. Structural analysis, EMI, and even lightning strike were considerations in the design solution.
Results & Outcome
Ingenium’s design and manufactured assemblies were an immediate success. The first iteration was an effective solution, and Ingenium Aerospace was awarded a multi-year contract for hundreds of actuators per year. Ingenium continues to improve the design and recently proposed cost savings and manufacturability improvement ideas, which have been accepted and implemented. A new long term agreement (LTA) has been executed and Ingenium Aerospace will be the program provider for years to come.