Page 407 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

Steam Turbines and Turbo~~s 385

3. Place a jack, wooden blocks or other adequate support under the
steam end of the turbine casing and steam chest.
4. Remove the bolts (30) securing the support (29) to the bearing
housing (21 and 53).
5. Loosen the socket head cap screws (23) and pry the bearing housing
away from the turbine casing until the spacers (24) are free to
move.
4. Remove the cap screws and spacers. Mark the spacers so they can
be returned to their original locations.

Caution: If the spacers (24, Figure 8-5)are not replaced in their
original locations, bearing misalignment may result. This
can cause uneven bearing wear or possible bearing fail-
ure. Nozzle ring to rotating blade clearance may also be
affected, resulting in poor performance or mechanical
failure.

7. Pull the bearing housing off the dowel pins (25).

Replacement
Note: Bearing liner anti-rotation grooves must be provided at the
horizontal split on replacement bearing housings.

1. Push the bearing housing onto the dowel pins (25, Figure 8-5) which
are pressed into the steam end turbine casing.
2. Replace the cap screws (23) and spacers (24). Ensure that the spac-
ers are returned to the same location from which they were re-
moved.
3. Bolt the support (29) to the bearing housing.
4. Replace the rotor assembly as outlined in Replacement Section.
5. Replace the bottom half journal bearing liners (15), check the bear-
ing alignment and adjust as necessary.

Exhaust End Bearlng Pedestal and Steam End Bearing Houslng Alignment

To obtain the correct bearing and rotor shaft journal contact, the bores
of the exhaust end bearing pedestal and the steam end bearing housing
must be in parallel and angular alignment. Dowel pins (25, Figure 8-5),
pressed into the turbine casing, position the pedestal and bearing housing
in horizontal and vertical parallel alignment. Spacers (24), located be-
tween the pedestal and turbine casing and between the steam end bearing