Sundyne LMV-313, Instruction And Operation Manual

Page: 31 / 82

Instruction and Operation Manual
27
Inspection and Cleaning and Repair
Inspecting All Bearings
Replace bearings if:
•
They have been in operation for over
three years
•
If rotation is not smooth
•
If outside of inside diameters are worn
Note: Only replace bearings with
manufacturer’s approved replacement
bearings. Non-approved bearings may
jeopardize the mechanical integrity of
the gearbox and pump.
Note: Refer to the Specifications section of
the manual for all bearing and shaft
clearances.
High Speed Shaft
Inspect the High Speed Shaft at the thrust
washer and journal bearing contact areas.
Replace the shaft and gear assembly if:
•
Outside diameter of shaft is less than
1.4960 inches
•
If the shaft has bearing or washer
materials on it’s surface
•
Shows signs of overheating
•
Shows wear to a depth greater than
0.001” (0.03mm)
Inspect upper and lower thrust washers or tilting
pad bearing assembly. If metal is smeared into
radial lube grooves of the washer face, install a
new washer. If the tilting pads do not fit freely, or
if they show signs of metal pick-up or
overheating, install a new bearing assembly.
Note: The radial “free play” of the high speed
shaft can be as high as 0.011 inch
(0.28mm) due to the clearance in the
bearings. It is not possible to check for
shaft straightness while the gearbox is
assembled. To check straightness, the
shaft must be placed in V-blocks, on it’s
bearing journals, and have runout
measured at the impeller fit (0.0018
inch TIR max).
Gearbox Mechanical Seal
Carefully inspect the seals for abrasive particles,
excessive seal face wear and any binding of the
seal face washer.
Replace or rebuild a faulty mechanical seal.
Seals may be rebuilt by replacing the seal face
washer, wedge rings, o-ring, and springs. A seal
repair kit is available.
Replace or lap the seal rotating face if the wear
track is rough or worn to a depth greater than 2
helium light bands.
A combined total of 0.010 inch (0.25mm)
maximum may be removed from the surfaces of
the pump and gearbox seal rotating faces.
Excess material removal will result in incorrect
seal face loading causing increased seal
leakage.
Remove any high spots on the end surfaces of
the lower shaft sleeve and impeller hub to insure
that the seal rotating face will not be distorted by
clamping force of the impeller bolt.
Reassemble the seal, throttle bushing, if used
seal housing, and impeller using an o-ring repair
kit. All o-rings that were disturbed by
disassembly should be replaced. During
reassembly, carefully check the torque values
listed in Table 7.
The impeller may rub on the diffuser cover plate
(15) until o-rings (936D and 936E) are
compressed by tightening hex nuts (914A).
Check the gearbox input shaft for freedom of
rotation after the pump is assembled and all
bolts are tightened per Table 7.