Advertisement
Be sure the axial positioning roll pin is in the dis-
charge end shaft bearing and screw the pulling rods
into the bearing. After coating the shaft journal and
the bearing ID with Molycote and oil, carefully slide
the bearing as far over the rotor shaft as it will go.
If a helper is available use a fulcrum and pry bar
under the rotor hex flat to raise the rotor slightly
while pushing the bearing into final position. On
large units, two oil pump housing bolts can be
screwed into the bottom holes in the sump face with
a strong back across them and a screw jack used to
raise the rotor. It is absolutely essential for the bear-
ing to slip into place easily by hand. Do not use
force to position the bearing.
3. Contrary to appearances, the oil pump does not sit
against the end of the rotor. The oil pump seats
against the shaft shoulder at the end of the journal
surface (See Fig. 21). This shoulder must be abso-
lutely perpendicular to the shaft axis or the oil pump
will wobble. Dirt or other irregularities will also
offset the pump.
The oil pump thrust face is an ex-
tremely smooth lapped surface. In or-
der to hold pump securely in place af-
ter bolt-up, do not allow any lubricant
on this area during assembly.
4. Set the oil pump on the shaft, screw the new clamp-
ing bolt finger tight and turn the oil pump opposite
to the direction of the shaft rotation until it sits
against the shaft hex flat. This assures positive drive
without the possibility of slippage. Snug the clamp-
ing bolt gently with a socket wrench.
5.
A. Set up a dial indicator capable of reading to
0.0005" on the rim of the large O.D. to check
oil pump run-out. Use a magnetic base or screw
an oil pump housing bolt into the sump. Turn
the pump and rotor by the clamping bolt using
a long extension.
B. Using a soft hammer or brass drift, center the
pump to within the following specifications:
25"
.0005"
26"
.0006"
38"
.0008"
55"
.001"
The above values are max. allowable. Try to get
within .0003". If the dimension cannot be achieved,
remove the pump, recheck for burrs or dirt, rotate
the pump 180° and repeat steps 4 and 5.
YORK INTERNATIONAL
C. Reset the indicator to read the reverse thrust face
of the pump. Be careful the grooves and relief
areas don't upset the indicator. A large diam-
eter "foot" may be easier to use while taking
this measurement.
FIG. 22 – CHECKING ALIGNMENT OF OIL PUMP
D. Tighten the oil pump clamping screw to the cor-
rect torque value. Refer to the compressor draw-
ing for the torque value.
E. Recheck the alignment of the pump. If it has
shifted, loosen the clamping screw and repeat
steps A through D.
6.
A. Slide the volute seal ring over the oil pump
and check the diameter clearance with a feeler
gauge (See Fig. 21). If the volute is acceptable,
(See Table 12) position it over the locating pin
in the oil pump housing and lock it in place with
the snap ring.
B. Install the reverse thrust bearing over the locat-
ing pin.
C. Install the pump guide pins and position the re-
quired amount of pump gaskets over the pins.
Coat all bearing and pump surfaces with
Molycote and oil. Slide the oil pump housing
into position. If you have the two piece oil
pump housing, snug the two locating bolts and
recheck the volute radial clearance. Center if
required. Torque bolts and install the pump
housing cover. Tighten bolts to approximately
FORM 220.11-NM2 (602)
4
LD07338
49
Advertisement
