Installation of gear assemblies in aircraft gearboxes

A method of assembling an aircraft gearbox, the method comprising:

• mounting a first outer race and a first plurality of rollers of a first roller bearing in a first opening of a gearbox housing and mounting a second outer race and a second plurality of rollers of a second roller bearing in a second opening of the gearbox housing;
• mating a first cylindrical guide sleeve having a first lead-in chamfer with a first gear assembly having a first double-helical gear and a first cylindrical shaft such that a trailing shoulder of the first guide sleeve is positioned proximate a leading shoulder of the first shaft, the first shaft including a first inner race of the first roller bearing;
• mating a second cylindrical guide sleeve having a second lead-in chamfer with a second gear assembly having a second double-helical gear and a second cylindrical shaft such that a trailing shoulder of the second guide sleeve is positioned proximate a leading shoulder of the second shaft, the second shaft including a second inner race of the second roller bearing;
• prior to coupling the first and second gear assemblies with the gearbox housing, forming a double-helical gear system by meshing the first double-helical gear and the second double-helical gear;
• and
• coupling the double-helical gear system to the gearbox housing by:
• simultaneously radially outwardly urging the rollers of the first plurality of rollers toward the first outer race by coaxially passing the first lead-in chamfer through the first plurality of rollers and radially outwardly urging the rollers of the second plurality of rollers toward the second outer race by coaxially passing the second lead-in chamfer through the second plurality of rollers;
• simultaneously axially passing the leading shoulder of the first shaft through the first plurality of rollers after the rollers of the first plurality of rollers have been radially outwardly urged toward the first outer race by the first guide sleeve and axially passing the leading shoulder of the second shaft through the second plurality of rollers after the rollers of the second plurality of rollers have been radially outwardly urged toward the second outer race by the second guide sleeve;
• simultaneously positioning the first inner race relative to the first plurality of rollers to form the first roller bearing and positioning the second inner race relative to the second plurality of rollers to form the second roller bearing;
• and
• removing the first and second guide sleeves from the first and second gear assemblies.

A method of assembling an aircraft gearbox, the method comprising:

• mounting a first outer race and a first plurality of rollers of a first roller bearing in a first opening of a gearbox housing, mounting a second outer race and a second plurality of rollers of a second roller bearing in a second opening of the gearbox housing and mounting a third outer race and a third plurality of rollers of a third roller bearing in a third opening of the gearbox housing;
• mating a first cylindrical guide sleeve having a first lead-in chamfer with a first gear assembly having a first double-helical gear and a first cylindrical shaft such that a trailing shoulder of the first guide sleeve is positioned proximate a leading shoulder of the first shaft, the first shaft including a first inner race of the first roller bearing;
• mating a second cylindrical guide sleeve having a second lead-in chamfer with a second gear assembly having a second double-helical gear and a second cylindrical shaft such that a trailing shoulder of the second guide sleeve is positioned proximate a leading shoulder of the second shaft, the second shaft including a second inner race of the second roller bearing;
• mating a third cylindrical guide sleeve having a third lead-in chamfer with a third gear assembly having a third double-helical gear and a third cylindrical shaft such that a trailing shoulder of the third guide sleeve is positioned proximate a leading shoulder of the third shaft, the third shaft including a third inner race of the third roller bearing;
• prior to coupling the first, second and third gear assemblies with the gearbox housing, forming a double-helical gear system by meshing the first double-helical gear with each of the second and third double-helical gears;
• and
• coupling the double-helical gear system to the gearbox housing by:
• radially outwardly urging the rollers of the first plurality of rollers toward the first outer race by axially passing the first lead-in chamfer through the first plurality of rollers, radially outwardly urging the rollers of the second plurality of rollers toward the second outer race by axially passing the second lead-in chamfer through the second plurality of rollers and radially outwardly urging the rollers of the third plurality of rollers toward the third outer race by axially passing the third lead-in chamfer through the third plurality of rollers;
• axially passing the leading shoulder of the first shaft through the first plurality of rollers after the rollers of the first plurality of rollers have been radially outwardly urged toward the first outer race by the first guide sleeve, axially passing the leading shoulder of the second shaft through the second plurality of rollers after the rollers of the second plurality of rollers have been radially outwardly urged toward the second outer race by the second guide sleeve and axially passing the leading shoulder of the third shaft through the third plurality of rollers after the rollers of the third plurality of rollers have been radially outwardly urged toward the third outer race by the third guide sleeve;
• positioning the first inner race relative to the first plurality of rollers to form the first roller bearing, positioning the second inner race relative to the second plurality of rollers to form the second roller bearing and positioning the third inner race relative to the third plurality of rollers to form the third roller bearing;
• and
• removing the first, second and third guide sleeves from the first, second and third gear assemblies.