Rotor assembly. The rotor assembly (fig. 6-4) is a
major unit of the M61A1 gun. The front section or stub
rotor supports the six barrels. The main body of the
rotor assembly contains the rotor tracks, rotor drive gear,
and the locking lugs to lock the barrels in place.
The rotor tracks support the breech-bolt assemblies
and provide a guide for the forward and backward
movement of the bolt. There are six sets of rotor tracks
attached to the ribs along the rotor body. Each set
contains a front, center, and rear removable track. The
removable track lets you install or remove a bolt
assembly for servicing or replacement. The necessary
front support for the rotor assembly consists of a double
row of ball bearings. The rear is supported by needle
bearings located inside the rotor body. The end plate
provides the inner race for the needle bearings, and it
also provides for the gun’s rear support.
Rear housing assembly and associated parts.
The rear housing assembly (figs. 6-5 and 6-6) is a major
unit of the gun. It consists of an upper section and a
lower section assembled as one unit. The rear housing
assembly provides the main cam path that controls the
movement of the breech-bolt assemblies. The elliptical
(oval) shape of the main cam path causes the forward
and backward movement of the bolt assemblies. The
clearing-cam path is circular and located at the rear of
the housing. It provides a path for the bolt assemblies
during the gun’s clearing cycle. The housing cover,
Figure 6-6.—Rear housing assembly and related parts (internal view).
6-5
