machine rotors should be supported, while being moved
do more damage to a machine during disassembly and
or when stationary, by slings, blocking under the shaft,
assembly than it will receive in years of normal service.
a padded cradle, or thickly folded canvas under the core
Figures 7-21 and 7-22 show typical ac and dc
laminations. When you are using rope slings to lift ac
motors.
or dc rotors, place them under the shaft, keeping them
clear of the bearing journals. When construction of the
Never be hasty or careless in disassembling a
rotors does not allow room, except around the bearing
generator or motor. Handle the delicate components
journals, you must protect the surfaces with heavy paper
with care to prevent damage or create the need for
or canvas. Ensure rope slings never come in contact
additional adjustment. Use the proper tools, and label
with ac or dc rotor coils. When the complete unit (stator
the parts as you dismantle them. Store them in an
and rotor) is to be lifted by lifting the starer, the bottom
orderly arrangement in a safe place. Note the necessary
of the air gap must be tightly shimmed unless both ends
of the shaft are supported on the bearings. It is possible,
information so that you will have no trouble in
by rough handling or careless use of bars or hooks, to
reassembly.
Figure 7-21.--Typical ac motor.
7-18
