Maximum Torque Override (MTO) Actuator

On aircraft carrier fight decks, the failure to lower Jet Blast Deflector #3 (JBD#3) causes undue strain on flight recovery operations due to the location of JBD#3, which is in the landing path of aircraft. A failure of JBD#3 to lower creates the greatest need for a redundant system. Failures can occur in either the electrical system or mechanical components of the blast doorÆs electromechanical actuator (EMA); resulting in delays to critical operations. The current safety protocol for lowering a JBD in the event of a primary failure mode is crew member intensive, can take in excess of 12 minutes and has the potential to cause damage to humans and equipment alike. The current emergency retraction process uses gravity and a friction brake operated by crew members to close the JBD.Ā Higher than normal resistance in the EMA due to minor damage of the EMAÆs roller screw assembly has been identified as a critical issues for current emergency retraction processes.Ā In this failure mode, the force due to gravity is insufficient to retract the JBD. The proposed improvement to the EMA provides a solution to all identified failure modes, applies to all JBDs on the vessel and potentially other EMA applications. Orbital Traction, Ltd. proposes to design and integrate into the current EMAs a remotely controlled, secondary actuator to lower the JBD in the event of a primary system failure e.g.Ā electrical system, drive motor or control. The back-up actuator provides maximal torque override (MTO) allowing for full system torque to be provided through the EMA using the MTO actuator in conjunction with a backup electrical power or portable power supply.Ā In the event of a primary system failure, a crew member remotely controls the MTO to actively lower the JBD. As a backup system, the MTO will lower the JBD in approximately 2 minutes, which is significantly less than the current 12-minute requirement. The MTO actuator is directly coupled to the EMAÆs electric motor on the far side of the roller screw interface.Ā The MTO is a low speed, high torque, rotary actuator that can be hardwired using a range of back-up electrical power sources including 24V portable equipment or power supply. The MTO has a small electric motor and an infinitely variable transmission (IVT).Ā The IVT allows the MTO to provide very high torque into the EMA drive mechanism with the small motor. The IVT utilizes a proprietary adjustable speed drive coupled with a geared differential.Ā The MTOÆs ability to deliver full system torque will overcome currently identified limitations associated with higher than normal resistance due to minor damage of the EMAÆs roller screw assembly and allow emergency operation of the EMA. The MTO will not impact the EMAÆs function during normal operations.