Abstract: A monitoring system is provided to ensure continued efficient reliable operation of an aircraft drive wheel drive system, preferably an aircraft drive wheel drive system driven by actuating drive system-actuated drive means, designed to drive an aircraft autonomously during ground operations. The monitoring system includes an array of sensor elements capable of obtaining desired information relating to selected drive system operating parameters and performance indicators during aircraft ground operations. The sensor elements are designed to be functionally located externally of drive system components to obtain information during aircraft ground movement under a range of operating conditions. The operating parameters and/or performance indicators to be monitored preferably include at least drive wheel speed and direction, drive means speed, drive means temperature, and drive means clutch engagement.

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 powered aircraft wheel is designed to include multiple wheel sections configured to define a cavity within the wheel and to support completely within the wheel cavity an onboard non-engine drive means controllable to move an aircraft autonomously without reliance on aircraft engines during taxi and ground travel. Each part of the powered wheel may be constructed of a material specifically selected to emphasize a functional property of the material that is optimal for the function of the wheel part at a specific location. The selected combination of functionally distinct materials gives the powered aircraft wheel a unique optimal structural and functional capability.

Abstract: A method is provided for restoring mobility to an aircraft equipped with at least one self-propelled drive wheel powered by a driver when the aircraft has been rendered immobile as a result of one or more wheel tires adhering to and becoming stuck to tarmac or another ground surface. The method uses forces generated by the cooperative action of the wheel driver, the aircraft steering, and the aircraft braking system to release adherent tires of each set of main wheels and/or nose gear wheels by applying differential force to one set of wheels at a time to release any adherent tires so that the aircraft is able to move on the ground surface and travel in a desired direction at a desired speed.

Abstract: An efficient system and method are provided wherein aircraft may be retrofitted with non-engine drive means controllable to power landing gear wheels to move the aircraft autonomously during ground movement without engines or tow vehicles so that existing landing gear structures are employed to achieve force distribution and load transfer. Non-engine drive means capable of powering a landing gear wheel to move the aircraft during taxi are integrated into existing landing gear designs so that excess drive forces are transferred and distributed through previously evaluated and certificated landing gear structures, including tow fittings, determined to be capable of handling such forces, which eliminates changes to the landing gear and facilitates retrofit and certification. Engines-off taxi technology can be rapidly designed and developed to be retrofitted on existing aircraft nose and/or main landing gear and then efficiently certificated.

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 torque transmission system is provided for an aircraft drive wheel drive system mounted on nose or main landing gear wheels to move the aircraft autonomously on the ground that effectively transmits torque through drive system components. The drive system includes a drive means capable of generating sufficient torque to move the aircraft, a drive system capable of generating a high torque capacity that activates the drive means, a clutch assembly that can be selectively engaged to control torque transmission to the drive system and activate the drive means, and a landing gear torque takeout element. The clutch assembly is configured to be inactivated and prevented from transmitting torque to other drive wheel drive system components when an overtorque event occurs. Aircraft drive wheel drive system components in the present torque transmission system are designed to withstand torque in excess of a determined maximum for the system.

Abstract: A bearing arrangement for an aircraft landing gear wheel is provided that effectively supports the wheel on an axle while maximizing internal wheel volume available for mounting a non-engine drive motor used to power the wheel and/or brakes or other structures within the maximized wheel volume. The bearing arrangement is preferably employed with a two-part aircraft wheel mounted on a landing gear axle and includes bearing structures located only on wheel sections adjacent to the axle. A specifically configured cantilevered joint portion of inboard and outboard wheel sections supports weight and loads bearing structures, eliminating the need for and space required by a high speed bearing. Stiffness necessary for strength and structural integrity is provided by the materials selected to form the wheel sections.

Abstract: A wheel testing system and method are provided that simulates realistically conditions likely to be encountered during operation of vehicle wheels, especially powered drive wheels and wheel-connected structures. The system may include an integral support frame designed to adjustably mount wheels or wheel-connected structures to be tested, a load motor drivingly connected to an inertial load, and an adjustable mounting sled configured to adjustably mount a test wheel or a wheel-connected structure with an hydraulic system actuatable to adjust the location of the test wheel relative to the inertial load to vary or fix the load on the test wheel desired. Speed of the test wheel can be varied or fixed by controlling the speed of the load motor. System measurement and data collection electronics measure a range of selected wheel parameters and gather data for transmission to a processor or non-transitory storage medium for processing and evaluation.

Abstract: A torque transmission system is provided for an aircraft drive wheel drive system mounted on nose or main landing gear wheels to move the aircraft autonomously on the ground that effectively transmits torque through drive system components. The drive system includes a drive means capable of generating sufficient torque to move the aircraft, a drive system capable of generating a high torque capacity that activates the drive means, a clutch assembly that can be selectively engaged to control torque transmission to the drive system and activate the drive means, and a landing gear torque takeout element. The clutch assembly is configured to be inactivated and prevented from transmitting torque to other drive wheel drive system components when an overtorque event occurs. Aircraft drive wheel drive system components in the present torque transmission system are designed to withstand torque in excess of a determined maximum for the system.

Abstract: A monitoring system is provided to ensure continued efficient reliable operation of an aircraft drive wheel drive system, preferably an aircraft drive wheel drive system driven by actuating drive system-actuated drive means, designed to drive an aircraft autonomously during ground operations. The monitoring system includes an array of sensor elements capable of obtaining desired information relating to selected drive system operating parameters and performance indicators during aircraft ground operations. The sensor elements are designed to be functionally located externally of drive system components to obtain information during aircraft ground movement under a range of operating conditions. The operating parameters and/or performance indicators to be monitored preferably include at least drive wheel speed and direction, drive means speed, drive means temperature, and drive means clutch engagement.

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.

Abstract: A powered aircraft wheel is provided that is designed to include multiple wheel sections configured to define a cavity within the wheel and to support completely within the wheel cavity an onboard non-engine drive means controllable to move an aircraft autonomously without reliance on aircraft engines during taxi and ground travel. Each part of the powered wheel may be constructed of a material specifically selected to emphasize a functional property of the material that is optimal for the function of the wheel part at a specific location. The selected combination of functionally distinct materials gives the powered aircraft wheel a unique optimal structural and functional capability.

Abstract: A method is provided for restoring mobility to an aircraft equipped with at least one self-propelled drive wheel powered by a driver when the aircraft has been rendered immobile as a result of one or more wheel tires adhering to and becoming stuck to tarmac or another ground surface. The method uses forces generated by the cooperative action of the wheel driver, the aircraft steering, and the aircraft braking system to release adherent tires of each set of main wheels and/or nose gear wheels by applying differential force to one set of wheels at a time to release any adherent tires so that the aircraft is able to move on the ground surface and travel in a desired direction at a desired speed.

Abstract: A clutch designed to effectively transfer torque between wheel drive system components in a vehicle drive wheel drive system to move the vehicle on a ground surface is provided. The wheel drive system components may include a non-engine drive means and a roller traction drive in torque transmission contact with the clutch and with the vehicle drive wheel. The clutch includes complementarily configured clutch components designed to mesh into engaging contact when activated by electromagnetic or other external engagement actuation means to transfer torque through an interface to a vehicle wheel. Drag and friction produced by activation of adjacent rotating patterned clutch elements amplifies axial forces to cause clutch elements to mesh into locking engagement to control transfer of torque between a non-engine drive means and a roller traction drive system to drive an aircraft landing gear wheel or other vehicle wheel.

Abstract: An efficient system and method are provided wherein aircraft may be retrofitted with non-engine drive means controllable to power landing gear wheels to move the aircraft autonomously during ground movement without engines or tow vehicles so that existing landing gear structures are employed to achieve force distribution and load transfer. Non-engine drive means capable of powering a landing gear wheel to move the aircraft during taxi are integrated into existing landing gear designs so that excess drive forces are transferred and distributed through previously evaluated and certificated landing gear structures, including tow fittings, determined to be capable of handling such forces, which eliminates changes to the landing gear and facilitates retrofit and certification. Engines-off taxi technology can be rapidly designed and developed to be retrofitted on existing aircraft nose and/or main landing gear and then efficiently certificated.

Abstract: An aircraft ground control system that moves an aircraft on the ground between landing and take off without external mechanical assistance from airport tugs or tow vehicles or reliance on thrust produced by the aircraft's engines is provided. The aircraft ground control system interfaces only with an aircraft auxiliary power unit or other aircraft power supply, but otherwise operates independently of aircraft systems. A system integrator and controller links cockpit controls designed to actuate the transmission of power to system components and to activate system components only under predetermined conditions with selectively activatable drivers in driving connection with one or more aircraft wheels to move the aircraft on the ground at selected torques and speeds.

Abstract: A bearing arrangement for an aircraft landing gear wheel is provided that effectively supports the wheel on an axle while maximizing internal wheel volume available for mounting non-engine drive means used to power the wheel and/or brakes or other structures within the maximized wheel volume. The bearing arrangement is preferably employed with a two-part aircraft wheel mounted on a landing gear axle and includes bearing structures located only on wheel sections adjacent to the axle. A specifically configured cantilevered joint portion of inboard and outboard wheel sections supports weight and loads bearing structures, eliminating the need for and space required by a high speed bearing. Stiffness necessary for strength and structural integrity is provided by the materials selected to form the wheel sections.

Abstract: A wheel testing system and method are provided that simulates realistically conditions likely to be encountered during operation of vehicle wheels, especially powered drive wheels and wheel-connected structures. The system may include an integral support frame designed to adjustably mount wheels or wheel-connected structures to be tested, a load motor drivingly connected to an inertial load, and an adjustable mounting sled configured to adjustably mount a test wheel or a wheel-connected structure with an hydraulic system actuatable to adjust the location of the test wheel relative to the inertial load to vary or fix the load on the test wheel desired. Speed of the test wheel can be varied or fixed by controlling the speed of the load motor. System measurement and data collection electronics measure a range of selected wheel parameters and gather data for transmission to a processor or non-transitory storage medium for processing and evaluation.