Abstract: A medical instrument port is described for use with a surgical mask or other protective face covering. The medical instrument port provides a sealed pathway through which a medical instrument can be passed without exposing the clinician to aerosolized droplets expelled from the patient's respiratory system when the medical instrument is introduced into the patient's nasal and/or oral passages.

Abstract: A quill shaft which translates rotational energy between a gear and a drive shaft having a drive shaft spline includes a first leg having an inner spline which meshes with the drive shaft spline and a second leg concentric with the first leg and radially offset and separated from the first leg by a gap. The second leg includes an outer spline which meshes with the gear. The first leg is connected to the second leg at one end to allow for change to a gap size during while translating the rotational energy between the gear and a drive shaft.

Abstract: A rotary wing aircraft and method of operating a tail drive system thereof, wherein the tail drive system includes a gearbox that contains a first transmissive device and a second transmissive device in parallel, each transmissive device having an input operatively connected to a first shaft that is powered by the main rotor drive system. The first and second transmissive devices each have an output operatively connected to a second shaft that drives the secondary rotary device.

Abstract: A rotary wing aircraft and method of operating a tail drive system thereof, wherein the tail drive system includes a gearbox that contains a first transmissive device and a second transmissive device in parallel, each transmissive device having an input operatively connected to a first shaft that is powered by the main rotor drive system. The first and second transmissive devices each have an output operatively connected to a second shaft that drives the secondary rotary device.

Abstract: An aircraft is provided including an airframe, an extending tail, one or more engines supported by the airframe, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system positioned at the extending tail. The translational thrust system providing translational thrust to the airframe. A gearbox configured to transfer power from the engine to the main rotor assembly. A flight control computer to independently control one or more of the engine, the upper rotor assembly, the lower rotor assembly, and the translational thrust system. The flight control computer, in response to at least one control command, engages or disengages the translational thrust system, while maintaining controlled powered flight.

Abstract: An aircraft is provided including an airframe, an extending tail, and a counter rotating coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system including a propeller is positioned at the extending tail. The translational thrust system provides translational thrust to the airframe. A drive system is configured to operate both the main rotor system and the translational thrust system. The drive system includes a clutch configured to selectively couple or decouple the propeller from the drive system.

Abstract: A coaxial, dual rotor system includes a first rotor assembly positioned at a rotor axis. A first rotor quill shaft is operably connected to the first rotor assembly at the rotor axis to drive rotation of the first rotor assembly about the rotor axis. A nonrotating static mast extends along the rotor axis through the first rotor quill shaft. A second rotor assembly is positioned at the rotor axis. A second rotor quill shaft is operably connected to the second rotor assembly to drive rotation of the second rotor assembly about the rotor axis. The second rotor quill shaft is coaxial with the first rotor quill shaft and disposed inside of the static mast. A second rotor bearing is positioned between the second rotor assembly and the static mast to transfer loads from the second rotor assembly to the static mast.

Abstract: A gearbox system for a dual coaxial counter rotating rotor assembly includes an input shaft to input a first torque into the gearbox system and a transfer shaft operably connected to the input shaft to transfer the first torque therethrough. Two gear sets are operably connected to the transfer shaft. Each gear set includes a first output gear to transfer a second torque acting in a first direction to a first rotor of a rotor assembly and a second output gear to transfer the second torque acting in a second direction opposite the first direction to a second rotor of the rotor assembly. The second torque transferred by each gear set of the two gear sets is substantially equal.

Abstract: A rotor system includes a first rotor located at a rotor axis that imparts a first axial load and a first moment, and a first shaft connected to the first rotor at the axis. A first bearing connects a gearbox to the first shaft, transferring the first axial load from the first shaft to the gearbox. A second rotor located at the axis imparts a second axial load and a second moment. A second shaft is connected to the second rotor at the axis, the second shaft coaxial with the first rotor. A second bearing connects the gearbox to the second shaft, transferring the second axial load from the second shaft to the gearbox. A nonrotating standpipe is located at the axis radially between the first shaft and the second shaft. An intershaft bearing located at the standpipe reacts the first and second moments using the first and second bearings.

Abstract: An aircraft is provided and includes an airframe having main, pylon and tail sections, a rotor disposed at one of the pylon and tail sections and rotatable about a rotational axis to drive the airframe and a primary gearbox disposed within the main section of the airframe and a secondary gearbox disposed within one of the pylon and tail sections. The primary gearbox includes an outer housing rotationally fixed relative to the airframe and a driveshaft extending through the outer housing and coupled to the secondary gearbox to thereby drive rotation of the rotor relative to the airframe via the secondary gearbox. The aircraft further including a sensing system affixed to the outer housing and the driveshaft and configured to sense rotational characteristics of the driveshaft.

Abstract: A quill shaft which translates rotational energy between a gear and a drive shaft having a drive shaft spline includes a first leg having an inner spline which meshes with the drive shaft spline and a second leg concentric with the first leg and radially offset and separated from the first leg by a gap. The second leg includes an outer spline which meshes with the gear. The first leg is connected to the second leg at one end to allow for change to a gap size during while translating the rotational energy between the gear and a drive shaft.

Abstract: A gearbox system for a dual coaxial counter rotating rotor assembly includes an input shaft to input a first torque into the gearbox system and a transfer shaft operably connected to the input shaft to transfer the first torque therethrough. Two gear sets are operably connected to the transfer shaft. Each gear set includes a first output gear to transfer a second torque acting in a first direction to a first rotor of a rotor assembly and a second output gear to transfer the second torque acting in a second direction opposite the first direction to a second rotor of the rotor assembly. The second torque transferred by each gear set of the two gear sets is substantially equal.

Abstract: A gearbox system for a dual coaxial counter rotating rotor assembly includes an input shaft to input a first torque into the gearbox system and a transfer shaft operably connected to the input shaft to transfer the first torque therethrough. Two gear sets are operably connected to the transfer shaft. Each gear set includes a first output gear to transfer a second torque acting in a first direction to a first rotor of a rotor assembly and a second output gear to transfer the second torque acting in a second direction opposite the first direction to a second rotor of the rotor assembly. The second torque transferred by each gear set of the two gear sets is substantially equal.

Abstract: An aircraft is provided and includes an airframe having main, pylon and tail sections, a rotor disposed at one of the pylon and tail sections and rotatable about a rotational axis to drive the airframe and a primary gearbox disposed within the main section of the airframe and a secondary gearbox disposed within one of the pylon and tail sections. The primary gearbox includes an outer housing rotationally fixed relative to the airframe and a driveshaft extending through the outer housing and coupled to the secondary gearbox to thereby drive rotation of the rotor relative to the airframe via the secondary gearbox. The aircraft further including a sensing system affixed to the outer housing and the driveshaft and configured to sense rotational characteristics of the driveshaft.

Abstract: A coaxial, dual rotor system includes a first rotor assembly positioned at a rotor axis. A first rotor quill shaft is operably connected to the first rotor assembly at the rotor axis to drive rotation of the first rotor assembly about the rotor axis. A nonrotating static mast extends along the rotor axis through the first rotor quill shaft. A second rotor assembly is positioned at the rotor axis. A second rotor quill shaft is operably connected to the second rotor assembly to drive rotation of the second rotor assembly about the rotor axis. The second rotor quill shaft is coaxial with the first rotor quill shaft and disposed inside of the static mast. A second rotor bearing is positioned between the second rotor assembly and the static mast to transfer loads from the second rotor assembly to the static mast.

Abstract: A rotor system includes a first rotor located at a rotor axis that imparts a first axial load and a first moment, and a first shaft connected to the first rotor at the axis. A first bearing connects a gearbox to the first shaft, transferring the first axial load from the first shaft to the gearbox. A second rotor located at the axis imparts a second axial load and a second moment. A second shaft is connected to the second rotor at the axis, the second shaft coaxial with the first rotor. A second bearing connects the gearbox to the second shaft, transferring the second axial load from the second shaft to the gearbox. A nonrotating standpipe is located at the axis radially between the first shaft and the second shaft. An intershaft bearing located at the standpipe reacts the first and second moments using the first and second bearings.

Abstract: A vibration control system includes four mass discs located at a central axis and rotatable thereabout. Each mass disc includes a mass secured thereto wherein rotation of the four mass discs creates a vibratory force output. A power transfer assembly is located between adjacent mass discs of the four mass discs and is configured to transfer rotational energy between the adjacent mass discs. The power transfer assembly includes a power transfer shaft rotatable about a power transfer shaft axis and a power transfer disc connected to the power transfer shaft and in frictional contact with each of the adjacent mass discs at a contact point. When the power transfer shaft is rotated, a radial location of the contact point at each of the adjacent mass discs relative to the central axis is changed, altering the vibratory force.

Abstract: A gearbox system for a dual coaxial counter rotating rotor assembly includes an input shaft to input a first torque into the gearbox system and a transfer shaft operably connected to the input shaft to transfer the first torque therethrough. Two gear sets are operably connected to the transfer shaft. Each gear set includes a first output gear to transfer a second torque acting in a first direction to a first rotor of a rotor assembly and a second output gear to transfer the second torque acting in a second direction opposite the first direction to a second rotor of the rotor assembly. The second torque transferred by each gear set of the two gear sets is substantially equal.

Abstract: A gearbox assembly includes a first face gear driveable about a face gear axis in a first direction by at least one first pinion gear and a second face gear driveable about the face gear axis in a second direction opposite the first direction by at least one second pinion gear. A thrust bearing is located between the first face gear and the second face gear. The first face gear is configured to drive rotation of a first shaft in the first direction and the second face gear is configured to drive rotation of a second shaft in the second direction. Further disclosed is a power train for a rotary wing aircraft having a gearbox including a first face gear rotatable in a first direction and a second face gear rotatable in a second direction opposite the first direction.

Abstract: A gearbox assembly includes a first face gear driveable about a face gear axis in a first direction by at least one first pinion gear and a second face gear driveable about the face gear axis in a second direction opposite the first direction by at least one second pinion gear. A thrust bearing is located between the first face gear and the second face gear. The first face gear is configured to drive rotation of a first shaft in the first direction and the second face gear is configured to drive rotation of a second shaft in the second direction. Further disclosed is a power train for a rotary wing aircraft having a gearbox including a first face gear rotatable in a first direction and a second face gear rotatable in a second direction opposite the first direction.