Aircraft undercarriage wheel pre-rotating mechanism - has drive motors coupled to aircraft instrumentation to match wheel peripheral speed with aircraft ground speed

摘要

The aircraft undercarriage wheel prerotating mechanism, esp. for large aircraft, has a variable speed motor (3) driving the wheels through gearing (2) with a free-wheel (5). The motor is automatically switched on when the wheels are lowered. Through connection with flight instrumentation the motor speed is regulated so that wheel peripheral speed equals the aircraft speed over ground. The wheel upper halves may be shrouded to reduce air friction braking. As an alternative to the motor drive, an air turbine drive may be used with ambient air ducted onto radial blades mounted on the wheels.