Page 23 of 4
slide the bearings on so that the text on the bearing shoulder will make contact with the shaft shoulder. Use extreme caution to not
damage the bearing components or the splined shaft end when using the hydraulic press. Place a non-metal object between the
splined shaft end and the hydraulic press to prevent damage to the shaft. Insert both shafts and stand the pump on the splined
ends. Slide the rear bearings on, tap the keys (21) into place, and then slide on the gears (8), shoulder side towards the bearings.
Make sure the timing marks are aligned. Tap on the gears to seat the bearings properly. Slide on the tabwashers (12) and thread
on the slotted nuts (13). Slide on the rotors (3a) and place a nonmetal object between the rotors to keep the shafts from turning.
Tighten the nuts so that the shaft rotating torques shown in section 5.3 are achieved. The torque can be measured by inserting the
rotor bolts (14a, 14b) in the splined shaft ends with the rotors on. Do not set the tabs on the tabwashers. Remove the rotor bolts
and rotors. Push the rotor housing (1) onto the dowels (20) in the bearing housing and tap gently with a rubber mallet to seat it
properly. Insert the housing studs (15) and secure them with the split washers (44) and hex nuts (43). The
UNIBLOC
200, 250,
and 275 has one piece studs (15) and does not use items (43) and (44). To tighten these studs lock two M6 nuts against each other
on the stud end. Slide the rotors (3a) on to the corresponding shaft. One rotor and one shaft will be marked with identical
symbols. Secure the rotors with the rotor bolts (14). Measure the clearances between the rotors and the housing. If the measured
values at positions 8-11 do not correspond with those listed in section 5, then the shim ring(s) (11) must be changed. Remove the
rotor bolts, rotors, studs, and then the housing. Unscrew the slotted nuts and remove the tabwashers. Remove the shafts, gears,
and keys from the bearing housing. Tap out the front bearing cups only to reveal the shim ring(s). Insert an appropriate shim, and
then repeat the steps described in this section. If the clearances fall within the ranges specified, then proceed to section 4.5.2.2
4.5.2.2 Pump Assembly – Stainless Steel Rotors – Final Step
Lock the nuts in place by bending the tabwasher into the slots in the nut. Install the front oil seals (23) by first lubricating with oil
all contact areas on the shafts and bearing housing. The text on the seals should face out. Push the seals on with a sleeve flush
with the bearing housing. Stand the pump on the splined ends and fill the bearing housing cavity with approved oil listed in
section 5.2. Place the oil seal(s) (24; 24 & 45 for
UNIBLOC
200-275) in the bearing housing cover, text side out. Place the o-ring
(25) into the groove on the rear side of the bearing housing. Slide the cover onto the drive shaft taking care not to damage the oil
seal lips. Secure the cover with the bolts (18). Tap key (22) into place. Install the shaft seals and rotor housing as described in
section 4.4.
4.5.2.3 Pump Assembly – Polymer Rotors
Insert the shim rings (11) into the front
bores of the bearing housing (6). Oil the
front (9) and rear (10) bearing cones and
tap them into the bearing housing so that
the tapered edge can be seen when looking
into the bearing housing. If the bearings
have been removed from the shafts, they
must be pressed on with a hydraulic press
before the shafts are installed into the
bearing housing. Oil the shafts at the
bearing seat location and slide the bearings
on so that the text on the bearing shoulder
will make contact with the shaft shoulder.
Use extreme caution to not damage the
bearing components or the splined shaft
end when using the hydraulic press. Place
a nonmetal object between the splined
shaft end and the hydraulic press to
prevent damage to the shaft. Insert both
shafts and stand the pump on the splined
ends. Slide the rear bearings on, tap the
keys (21) into place, and then slide on the
gears (8), shoulder side towards the
bearings. Make sure the timing marks are
aligned. Tap on the gears to seat the
bearings properly. Slide on the tabwashers
