PRR

The Pennsylvania Railroad GG1: Quill Drive

Class GG-1 Quill Drive
Class GG-1 Quill Drive, Alvin F. Staufer Photo

The Quill Shaft Assembly was a critical component in the GG-1's traction-motor/drive wheel system, in that its function was to transmit power from the motors to the drive wheels.

The GG-1 Class locomotive had 12 traction motors, which powered the engine's six drive axles. These motors were rated at 385 HP each, thus providing 770 HP per axle for an engine total of 4620 HP. The traction motors, assembled in pairs, were single-ended, with each having a drive pinion mounted on one end of an armature shaft. Each pair of motors was connected to the driving wheels through the quill shaft assembly. This assembly was supported in a pair of journal bearings located beneath the two motors. In turn, these bearings were mounted in a housing that was integral to the motor-drive assembly.

The quill shaft was essentially a hollow tube that surrounded the drive axle. Mounted on one end of the quill shaft was a large bull gear which meshed with, and was driven by the pinions on the traction motors. Also mounted on each end of the quill shaft was a "spider-drive" assembly, on each of which were mounted six "drive-cup" assemblies. It was through the contact of these "drive-cups" with the radial spokes of the drive wheels, that power from the traction motors was finally delivered to the drive wheels. This arrangement of delivering the traction power of the motors to the drive wheel through the "drive-cups" allowed the driving wheels and axle to move in reaction to track conditions without affecting the meshing of the drive pinions and the bull gear.

Class GG-1 Quill
Class GG-1 Quill, Alvin F. Staufer Photo

Class GG-1 Traction Motors
Class GG-1 Traction Motors, Alvin F. Staufer Photo

Class GG-1 Quill Drive Assembly This is the quill drive assembly which includes the bull gear and the spring and cup assemblies which engage the diving wheels and absorbed the motor thrust and torque. The quill drive assembly is mounted under the traction motors and rides in the quill bearing in the traction motor assembly. Alvin F. Staufer Photo
Class GG-1 Axle Quill drive assembly engaged with the driving wheels. The wheel axle turns independently inside the hollow quill shaft. The driving wheels and axle can move in reaction to track conditions without affecting the meshing of the pinions and gears. Alvin F. Staufer Photo
Class GG-1 Traction Motor Assembly The twin traction motor assembly showing the pinion gears on each of the motor shafts. These pinions engage with the bull gear. Also notice the bearing at the bottom of the assembly in which the quill shaft rotates.

Notice in the photo of the Frame and Driving Wheels below that the placement of the driving wheel assembly was not symmetrical. The first two sets had the pinions and bull gear located on the right side and the other four sets of pinions and bull gears were located on the left side. This asymmetrical arrangement was necessary due to the placement of other equipment in the locomotive. Alvin F. Staufer Photo

Class GG-1 Frame and Driving Wheel Assemblies
Class GG-1 Frame and Driving Wheel Assemblies, Alvin F. Staufer Photo

References

Credits

Much thanks to Richard Duley and Peter Lerro who have helped to provide a great deal of the information found on this page.