the proper screw adjustment.

Main Bearings

The bearings which support the rotor are shown at F F in Fig. 34 and in
detail in Fig. 41. The bearing proper consists of a brass tube B with
proper oil grooves. It has a dowel arm L which fits into a corresponding
recess in the bearing cover and which prevents the bearing from turning.
On this tube are three concentric tubes, C D E, each fitting over the
other with some clearance so that the shaft is free to move slightly in
any direction. These tubes are held in place by the nut F, and this nut,
in turn, is held by the small set-screw G. The bearing with the
surrounding tubes is placed inside of the cast-iron shell A, which rests
in the bearing pedestal on the block and liner H. The packing ring M
prevents the leakage of oil past the bearing. Oil enters the chamber at
one end of the bearing at the top and passes through the oil grooves,
lubricating the journal, and then out into the reservoir under the
bearing. The oil also fills the clearance between the tubes and forms a
cushion, which dampens any tendency to vibration.

[Illustration: FIG. 41]

The bearings, being supported by the blocks or "pads" H, are
self-alining. Under these pads are liners 5, 10, 20, and 50 thousandths
in thickness. By means of these liners the rotor may be set in its
proper running position relative to the stator. This operation is quite
simple. Remove the liners from under one bearing pad and place them
under the opposite pad until a blade touch is obtained by turning the
rotor over by hand. After a touch has been obtained on the top, bottom,
and both sides, the total radial blade clearance will be known to equal
the thickness of the liners transferred. The position of the rotor is
then so adjusted that the radial blade clearance is equalized when the
turbine is at operating temperature.

On turbines running at 1800 revolutions per minute or under, a split
babbitted bearing is used, as shown in Figs. 42a and 42b. These bearings
are self-alining and have the same liner adjustment as the
concentric-sleeve bearings just described. Oil is supplied through a
hole D in the lower liner pad, and is carried to the oil groove F
through the tubes E E. The oil flows from the middle of this bearing to
both ends instead of from one end to the other, as in the other type.

[Illustration: FIG. 42A]

[Illustration: FIG. 42B]

Packing Glands

Where the shaft passes through the casing at either end