| 摘要 |
<p>An aircraft has a drive system 50 for rotating one or more wheels (16, fig 1) of the aircraft landing gear for the purposes of ground taxiing and/or spin-up prior to landing. The drive system includes a motor 52 operable to rotate a first drive pinion 60 via a first drive path, and a driven gear 20 adapted to be fixed to the wheel. The drive system has a first configuration in which the first drive pinion is capable of meshing with the driven gear to permit the motor to drive the driven gear via the first drive path. One of the first drive pinion and the driven gear comprises a first sprocket 80A and the other of the first drive pinion and the driven gear comprises a series of rollers arranged in two or more rows 82A,82B, each row of rollers being arranged to form a ring, each roller being rotatable about a roller axis at a fixed distance from an axis of rotation of the first drive pinion or driven gear, respectively. A second drive sprocket 80B is operable to rotate the second drive pinion via a second drive path. Such a drive system is switchable between the first configuration and a second configuration in which the second drive pinion is capable of meshing with the driven gear to permit the motor to drive the driven gear via the second drive path. The first drive path has a higher gearing ratio than the second drive path.</p> |
