May 16-17, 2007 - Wheelcase Assembly
The wheel case is an important part of the Merlin engine. Via the quill shaft, which is connected to the crank, the wheel case drives the cams, mags, various pumps, and the blower. The starter interfaces on the wheel case as well.
The Packard blower drive differs from the British. The Packard design has the quill bull gear driving three smaller gears, referred to as the ABC gears.
Each of these gears in turn drives a planetary set of gears. By locking or unlocking the the planetary assembly (via oil pressure and a one-way clutch), the blower drive speed can be shifted from high to low.
The exterior of the three planetary assemblies all drive a common central gear, which is attached to the blower spool.
Read MoreThe Packard blower drive differs from the British. The Packard design has the quill bull gear driving three smaller gears, referred to as the ABC gears.
Each of these gears in turn drives a planetary set of gears. By locking or unlocking the the planetary assembly (via oil pressure and a one-way clutch), the blower drive speed can be shifted from high to low.
The exterior of the three planetary assemblies all drive a common central gear, which is attached to the blower spool.
