Hamilton Sundstrand Company ACT2000 - Manual (Page 33)

nut to the main preloaded duplex thrust bearings. The thrust bearings
transfer the loads to the main housing by the main bearing and shaft
retaining nuts.
A motor end bearing is provided for additional radial shaft stability. The
resolver rotor, motor rotor, motor bearing, and spacers are all stacked on
the ball screw shaft and retained by a single nut. This arrangement
prevents actuator axial loads from passing through the resolver rotor and
motor rotor.
CH. 2: UNDERSTANDING THE ACT2000 27