Abstract: A clutch assembly for an aircraft drive wheel drive system to move an aircraft independently on the ground is provided. The clutch is mounted within an aircraft drive wheel to be operatively engaged and disengaged to selectively actuate a roller traction or other drive system to activate a non-engine drive means to drive the wheel and the aircraft. One embodiment of the clutch assembly includes a plurality of pivoted sprag elements selectively activatable to transmit torque between inner and outer clutch members and activate the drive wheel drive system. The clutch assembly may also include mating crown gear and straight gear elements integrated with the drive system to reduce stresses on the drive system as the drive means is actuated. Various arrangements of sprags and clutch assembly components may be provided to monitor and selectively control disengagement of the clutch assembly and communicate disengagement to selectively prevent drive system actuation.

Abstract: A clutch assembly for an aircraft drive wheel drive system to move an aircraft independently on the ground is provided. The clutch is mounted within an aircraft drive wheel to be operatively engaged and disengaged to selectively actuate a roller traction or other drive system to activate a non-engine drive means to drive the wheel and the aircraft. One embodiment of the clutch assembly includes a plurality of pivoted sprag elements selectively activatable to transmit torque between inner and outer clutch members and activate the drive wheel drive system. The clutch assembly may also include mating crown gear and straight gear elements integrated with the drive system to reduce stresses on the drive system as the drive means is actuated. Various arrangements of sprags and clutch assembly components may be provided to monitor and selectively control disengagement of the clutch assembly and communicate disengagement to selectively prevent drive system actuation.

Abstract: A roller traction drive system integral with a non-engine drive means and a clutch assembly in an aircraft drive wheel drive system capable of moving an aircraft autonomously on the ground is provided. The roller traction drive system is selectively activated by the clutch assembly into and out of actuating contact with the non-engine drive means to drive the aircraft drive wheel. Roller traction drive system components are made of materials designed to enable dry running and operation at the torques, drive means speeds, and reduction ratios required to actuate a drive means and drive a drive wheel for autonomous aircraft ground movement. Roller traction drive materials may be selected to maintain effective torque transfer between roller traction drive system components and the non-engine drive means as well as to minimize undesirable thermal expansion.