Page 410 - Practical Machinery Management for Process Plants Major Process Equipment Maintenance and Repair

388 Major Process Equipment Maintenance and Repair

2. Remove the retainer ring (51, Figure 8-5) with ring expanding pli-
ers.
3. Remove the locating bearing (50) with a bearing puller.

Clearances

To check the axial bearing clearance, an axial rotor float check must be
made:

1. Mount a dial indicator perpendicular to a vertical shaft face (such as
the coupling hub or a rotor disk).
2. Shift the rotor as far as possible in both axial directions while ob-
serving the dial indicator. The normal axial rotor float is from .010
in. (0.25 mm) to .018 in. (0.46 mm). In no case should the total
indicator reading exceed .025 in. (0.64 mm).

Adjustmentar

The rotor locating bearing is not adjustable. Worn bearings must be
replaced when the axial rotor float reaches .OD in. (0.64 m).

Assembly

1. Install the bearing on the shaft by using a sleeve type bearing driver
which contacts the inner bearing race. Seat the bearing solidly against
the machined shoulder on the shaft (43, Figure 8-5).

Note: Be sure the shielded side of the bearing is positioned toward
the trip body (52).

2. Replace the retainer ring (51). Seat the ring firmly in the groove on
the rotor shaft, with the beveled edge of the ring positioned toward
the trip body.
3. Replace the trip body as outlined in Trip Body Replacement Section
on page 400.
4. Flush the locating bearing with oil before replacing the bearing cap.

Nozzle Rlng and Revarslng Blade Assembly
The relative locations of nozzle rings and reversing blade assembly are
shown in Figure 8-11. The nozzle ring (33, Figure 8-5) directs the steam
flow from the steam chest to the blades of the first rotor disk (44). Steam
exits the blades of the first disk and passes through the reversing blade
assembly (37) which directs it into the blades on the second rotor disk