Landing gear drive system and method

Patent metadata

Field	Value
Publication number	US-10124887-B2
Application number	US-201515125614-A
Country	US
Kind code	B2
Filing date	Mar 13, 2015
Priority date	Mar 14, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A drive system for a landing gear is disclosed having a wheel rotatable about a wheel axis, the a drive assembly comprising an input gear rotatable about an input axis by an input shaft, an engagement assembly comprising a first intermediate gear meshed with the input gear and rotatable about a first intermediate axis by a first intermediate shaft, and a first drive pinion mounted on the first intermediate shaft and arranged to rotate in tandem with the first intermediate gear, the engagement assembly being pivotable about the input shaft relative to the drive assembly. A locking device is engageable to prevent rotation of the first intermediate gear about the first intermediate axis. The drive system also comprises a driven gear is configured to be attached to the wheel so as to be capable of rotating the wheel about the wheel axis.

First claim

The invention claimed is:

1. A drive system for a landing gear having a wheel rotatable about a wheel axis, the drive system including:
a drive assembly comprising an input gear rotatable about an input axis by an input shaft;
an engagement assembly comprising a first intermediate gear meshed with the input gear and rotatable about a first intermediate axis by a first intermediate shaft, and a first drive pinion mounted on the first intermediate shaft and arranged to rotate in tandem with the first intermediate gear, the engagement assembly being pivotable about the input shaft relative to the drive assembly;
a locking device which is engageable to prevent rotation of the first intermediate gear about the first intermediate axis; and
a driven gear configured to be attached to the wheel so as to be capable of rotating the wheel about the wheel axis,
wherein:
the drive system is arranged to move from a neutral configuration, in which the first drive pinion is not meshed with the driven gear and the locking device is engaged, to a first driven configuration, in which the first drive pinion is meshed with the driven gear and the locking device is disengaged, upon pivoting of the engagement assembly about the input shaft in a first direction in response to application of a torque to the input shaft in the first direction; and
one of the first drive pinion and the driven gear comprises a sprocket and the other of the first drive pinion and the driven gear comprises a series of rollers arranged to form a ring, each roller being rotatable about a roller axis at a fixed distance from an axis of rotation of the drive pinion or driven gear, respectively.

2. The drive system of claim 1 , wherein the engagement assembly includes:
a second intermediate gear meshed with the input gear and rotatable about a second intermediate axis by a second intermediate shaft; and
a second drive pinion mounted on the second intermediate shaft and rotatable in tandem with the second intermediate gear, one of the second drive pinion and the driven gear comprising a sprocket and the other of the first drive pinion and the driven gear comprising a series of rollers arranged to form a ring, each roller being rotatable about a roller axis at a fixed distance from an axis of rotation of the second drive pinion or driven gear, respectively, and
wherein the locking device is engageable to prevent rotation of the second intermediate gear about the second intermediate axis, and the drive system is arranged to move from the neutral configuration to a second driven configuration, in which the second drive pinion is meshed with the driven gear and the locking device is disengaged, upon the pivoting of the engagement assembly in a second direction opposite to the first direction in response to application of a torque to the input shaft in the second direction.

3. The drive system of claim 1 , including a resilient member arranged to bias the engagement assembly to the neutral configuration.

4. The drive system of claim 1 , including a stop member arranged to limit an amount by which the engagement assembly can pivot about the input shaft.

5. The drive system of claim 1 , wherein the locking device is engageable with the engagement assembly to prevent rotation of the first intermediate gear, and optionally the second intermediate gear.

6. The drive system of claim 5 , wherein the locking device comprises an engagement member arranged to engage the first pinion gear.

7. The drive system of claim 1 , wherein the locking device is arranged to automatically disengage in the first driven configuration, and optionally the second driven configuration.

8. The drive system of claim 1 , wherein the locking device is arranged to automatically engage in the neutral configuration.

9. The drive system of claim 3 , wherein the resilient member comprises a spring having a proximal end attached to the drive assembly and a distal end attached to the engagement assembly.

10. The drive system of claim 9 , wherein the distal end is attached to the engagement assembly by a coupling which permits sliding of the distal end relative to the engagement assembly.

11. The drive system of claim 10 , wherein the locking device comprises a lever having a first end connected to the distal end of the spring, a second end arranged to engage one or more teeth of the first pinion gear, and a pivot connection between the lever and the engagement assembly, whereby the pivot connection is arranged to permit pivoting of the lever relative to the engagement assembly in response to sliding of the distal end relative to the engagement assembly.

12. An aircraft landing gear having a wheel and a drive system according to claim 1 , wherein the driven gear of the drive system is attached to the wheel so that the wheel is arranged to rotate in tandem with the driven gear.

13. A method of operating a drive system to rotate a wheel of a landing gear about a wheel axis, the drive system including: a drive assembly including an input gear rotatable about an input axis by an input shaft; an engagement assembly including a first intermediate gear meshed with the input gear and rotatable about a first intermediate axis by a first intermediate shaft and a first drive pinion mounted on the first intermediate shaft and arranged to rotate in tandem with the first intermediate gear, the engagement assembly being pivotable about the input shaft relative to the drive assembly; a locking device which is engageable to prevent rotation of the first intermediate gear about the first intermediate axis; and a driven gear attached to the wheel so as to be capable of rotating the wheel about the wheel axis, wherein one of the first drive pinion and the driven gear comprises a sprocket and the other of the first drive pinion and the driven gear comprises a series of rollers arranged to form a ring, each roller being rotatable about a roller axis at a fixed distance from an axis of rotation of the drive pinion or driven gear, respectively, the method including the steps of:
engaging the locking device to prevent rotation of the first intermediate gear about the first intermediate axis;
applying a torque to the input gear in a first direction to thereby pivot the engagement assembly about the input axis in the first direction to a position in which the first pinion gear is meshed with the driven gear and the locking device is disengaged; and
continuing to apply the torque to the input gear in the first direction to rotate the driven gear in the first direction and thereby rotate the wheel about the wheel axis in the first direction.

14. The method of claim 13 , further including the step of applying a torque to the input gear in a second direction opposite to the first direction so that the engagement assembly pivots about the input axis in the second direction and the first pinion gear is no longer meshed with the driven gear.

15. The method of claim 13 , wherein the engagement assembly further includes: a second intermediate gear meshed with the input gear and rotatable about a second intermediate axis by a second intermediate shaft; and a second drive pinion mounted on the second intermediate shaft and rotatable with the second intermediate gear, one of the second drive pinion and the driven gear comprising a sprocket and the other of the first drive pinion and the driven gear comprising a series of rollers arranged to form a ring, each roller being rotatable about a roller axis at a fixed distance from an axis of rotation of the second drive pinion or driven gear, respectively, and the method includes the steps of:
engaging the loc

Assignees

• Airbus Operations Ltd

Inventors

• Didey Arnaud
• Wilson Fraser

Classifications

• B64C25/34

  wheeled type, e.g. multi-wheeled bogies · CPC title

• B64C25/405 Primary

  Powered wheels, e.g. for taxing · CPC title

• Y02T50/823

  Cross-Sectional Technologies · mapped topic

• Y02T50/80

  Energy efficient operational measures, e.g. ground operations or mission management · CPC title