Anti-rotation assembly

A method of assembling a gas turbine engine, the method comprising:

• engaging a locking sprocket on a first crenelated end rim of a first shaft;
• positioning a second shaft so that a second crenelated end rim of the second shaft is juxtaposed with the first crenelated end rim;
• axially moving the locking sprocket to engage the first crenelated end rim and the second crenelated end rim;
• and
• engaging an axial retaining ring in a circumferential groove defined in the first crenelated end rim to retain the locking sprocket in place;
• wherein:
• the first crenelated end rim defines a plurality of first crenels;
• the second crenelated end rim defines a plurality of second crenels;
• the locking sprocket comprises a body and a plurality of teeth extending from the body;
• the body of the locking sprocket is disposed radially inward of the first crenelated end rim and the second crenelated end rim;
• and
• axially moving the locking sprocket to engage the first crenelated end rim and the second crenelated end rim comprises inserting the plurality of teeth to extend into the plurality of first crenels and the plurality of second crenels to prevent relative rotation between the first shaft and the second shaft.

An anti-rotation assembly comprising:

• a first shaft comprising a first crenelated end rim defining a plurality of first crenels, wherein the plurality of first crenels are defined between a plurality of first merlons of the first crenelated end rim;
• a second shaft comprising a second crenelated end rim defining a plurality of second crenels, wherein the plurality of second crenels are defined between a plurality of second merlons of the second crenelated end rim;
• a locking sprocket comprising a plurality of teeth, wherein the locking sprocket is configured to engage the first crenelated end rim and the second crenelated end rim to anti-rotatably couple the first shaft to the second shaft, wherein the plurality of teeth are configured to extend into the plurality of first crenels and the plurality of second crenels to prevent relative rotation between the first shaft and the second shaft;
• and
• an axial retaining ring configured to axially retain the locking sprocket;
• wherein
• the plurality of first merlons are aligned with the plurality of second merlons and the plurality of first crenels are aligned with the plurality of second crenels;
• the plurality of first merlons collectively define a circumferential groove configured to receive the axial retaining ring;
• and
• the circumferential groove is disposed at an axial midpoint between first closed ends of the plurality of first crenels of the first crenelated end rim and second closed ends of the plurality of second crenels of the second crenelated end rim.