Nidec 22765-01, Manual

Page: 208 / 227

Page 37
Disassembly
Overall Disassembly
1. Remove the terminal box cover, and disconnect the load leads
and all other leads. Tag the leads to ensure they are correctly
connected when the generator is reassembled.
2. Remove the bolts securing the generator to the base and prime
mover, and move the generator to an area that allows sufficient
room for disassembly.
3. Remove the coupling or drive plates.
4. Remove the exciter cover.
5. Remove the clips securing the exciter field leads to the exciter
frame and endbracket. Disconnect the leads and remove the
exciter frame/stator and/or exciter-PMG frame/stator.
6. Remove the (optional) PMG and exciter armature as described
below.
7. Support the shaft. Remove the exciter-end endbracket bolts, and
remove the endbracket. Tap lightly with a rubber or fiber mallet
to loosen the endbracket if necessary. Repeat with the drive-end
endbracket (if applicable).
8. Remove the fan from the hub where applicable. If necessary,
make sure to mark the location of the fan for reinstallation.
9. Float out the rotor (see Figure 23). First attach a pipe over the
shaft on the drive end. Attach slings around the pipe on one end
and around the shaft on the opposite end. Lift up the rotor, and
move it out, resting the rotor as the slings are moved down the
pipe for the next lifting stage.
IMPORTANT: The following procedures
are meant to be a general guide.
Procedures for your unit may vary.
WARNING: Ensure the generator
has stopped and is de-energized before
disassembly. A rotating generator is
always producing some voltage and
contact with the leads or other devices
connected may result in serious injury or
death.
WARNING: Use a hoist and
slings or chains to support components
during removal. Use lifting devices that
are selected for generator component
weights. Improper lifting techniques
may cause serious injury or death.
Be extremely careful not to damage
components.
NOTE: Ensure the generator field wires
are flat in the wireway so they don’t
tear during pulling. Do not pull on the
edges of the heat sinks or on the exciter
armature windings.
NOTE: Make sure the pipe is strong enough
to support the weight of the rotor and
that it does not have rough edges on the
inside, which could damage the shaft
To prevent tension on the shaft, put
the slings around the largest shaft step
possible.
Make sure the rotor does not rest on the
stator during the stages of movement.
Make sure the rotor does not hit the
stator.
Figure 23 Floating the Rotor