Md2-c coupling disassembly, Assembly of coupling, Md2-b coupling disassembly – Viking Pump TSM341.1: SG Mag Drive Series User Manual
Page 14: Installation of carbon graphite bushings, Danger, Series md2-b and md2-c, all sizes danger, Caution

SECTION TSM 341.1
ISSUE
J
PAGE 14 OF 19
DANGER !
Before starting the pump, be sure all drive
equipment guards are in place.
Failure to properly mount guards may result in
serious injury or death.
MD2-C COUPLING DISASSEMBLY
The bearing carrier for the MD2-C coupling features two
tapered roller bearings secured by a threaded end cap. The
unit is greased externally using the grease fitting. If further
disassembly is required, reference
Figure 9 on page 7 and
Figure 15, then proceed as follows:
1. Remove the two setscrews from the bolt-on hub and
slide the outer magnet off of the shaft. Remove the
outboard drive key in shaft.
2. Place
the inboard side of the shaft in a vise with padded
jaws. Bend the lockwasher tab up and gently tap the
locknut in a counterclockwise direction. Remove the
locknut and lockwasher.
3. Loosen the two setscrews retaining the end cap. Back
out the end cap completely. Pull or gently tap the shaft
out the back of the bearing housing. Be sure to keep
the cup and cone of the outer bearing together. If either
the cup or cone requires replacing, it is recommended to
replace as a set. The inner cone will probably stay in the
housing unless it is to be replaced.
4. One lip seal is pressed into the end cap and the other is
pressed into the bearing housing. Do not remove the
lipseals unless they require replacement. If removed,
pay close attention to the orientation as shown in
Figure 15 when installing the new lip seals.
Series MD2-B and MD2-C, All Sizes
DANGER !
Follow these directions exactly to avoid injury
to self or damage to the pumping unit. Be care-
ful to keep the inner and outer magnets at least
(1) foot apart until step 4. Do not engage the
magnets in any other fashion.
CAUTION !
Do not place fingers onto the front of pump
mounting flange. Align the canister into bore
of the bracket and gently slide it in. When the
magnets start to engage, the unit will finish en-
gagement on its own very rapidly unless the
M10x120mm capscrew is properly used. Make
sure fingers are not on the front of the pump.
See Figure Sequence 19.
ASSEMBLY OF COUPLING
MODELS
RECOMMENDED CAPSCREW TORQUE
SG-10 / SG-410
80 ft. lbs. (110 Nm)
SG-14 / SG-414
100 ft. lbs. (140 Nm)
SG-810 & SG-814
PUMP ASSEMBLY
1. Be sure to clean the bracket and casing thoroughly. If the
bearings were removed, install new pump bearings into
each bore using an arbor press. If carbon graphite, Refer
to “Installation of Carbon Graphite Bushings” below.
2. Assemble the shaft / gear assemblies. Install one snap
ring onto the shaft. Place the anti rotation pin into its
groove on the shaft. Slide the gear over the pin and lock
into place using the second snap ring.
NOTE: Make sure
the snap rings do not block the flow path along the gear
ID.
3. Coat shaft / gear assemblies with light oil. Place both
shafts in the casing with the drive shaft (longer shaft) on
the top (nameplate side).
4. Lubricate the casing O-ring and place it in the groove.
5. Place the pump bracket onto the casing. Tighten the
capscrews evenly.
MD2-B COUPLING DISASSEMBLY
The bearing carrier for an MD2 B coupling features two
sealed ball bearings along with the outer magnet assembly.
If further disassembly of this unit is required, reference
Figure 8 on page 6 and Figure 14, then proceed as follows:
1. Remove the internal retaining ring. Using a press, press
the shaft out of the housing.
2. Remove the external retaining rings from shaft. Place
the unit into the press and push out shaft out of the
bearings.
INSTALLATION OF CARBON
GRAPHITE BUSHINGS
When installing carbon graphite bushings, extreme care must
be taken to prevent breaking. Carbon graphite is a brittle
material and is easily cracked. If cracked, the bushing will
quickly disintegrate. Using a lubricant and adding a chamfer
on the bushing and the mating part will help in installation.
The additional precautions listed below must be followed for
proper installation.
1. A press must be used for installation.
2. Be certain bushing is started straight.
3. Do not stop pressing operation until bushing is in proper
position. Starting and stopping will result in a cracked
bushing.
4. Check bushing for cracks after installation.
Carbon graphite bushings with extra interference fits are
frequently furnished for high temperature operation. These
bushings must be installed by a shrink fit.
1. Heat bracket or idler to 750ºF.
2. Install cool bushing with a press.
3. If facilities are not available to reach 750ºF temperature,
it is possible to install with 450ºF temperature; however
the lower the temperature, the greater the possibility of
cracking the bushing.
Consult factory with specific questions on high temperature
applications.