18
Rotor Timing
Rotor timing is critical for the pump operation and must be precisely maintained to provide maximum
pumping efficiency, yet prevent contact between rotors during operation. If pumping efficiency is
below expectations, or if rotors contact during operation (within rated differential pressure), check
rotor timing and adjust if incorrect. Also check rotor timing after any gearbox dismantling when the
gears are removed and/or replaced.
Check Rotor timing as follows:
1. Assemble each rotor in its normal location on the drive shaft and the idle shaft. Assemble each
rotor bolt and tighten hand tight.
2. Rotate the shafts 30 degrees and measure gap as
illustrated by arrows in Figure 34. Rotate the
shafts 60 degrees to the opposite direction and
measure the gap as illustrated.
3. The Rotors are correctly timed when the gap
measured at both locations are equal. If the gap
is unequal, adjust the timing as follows.
4. Rotor timing is determined by the relative location
of the two helical gears (14) on the shafts. Gear
spacers (16) are used to adjust the location and
the timing. When adjusting timing, move only
one of the two gears.
5. Bend away the tab of the lock washer (12) on
drive shaft, loosen the lock nut and remove gear.
Insert a NEW gear spacer(6mm) on drive shaft,
gear, lock nut and lock washer consequently and
tighten referring the ‘Gearbox Assembly’ in page
22. Finally, adjust the rotor timing to be correct.
6. If the rotor timing is correct, measure the gap of the gear
between drive shaft and idle shaft using depth
micrometer shown in Figure 35. Adjust the gap using
spacer and shim(s) according to the below cases.
* If the gap is (+) value (idle shaft is more embossed
than drive shaft) as shown in Figure 36, combined
6mm spacer & shim(s) and add on the idle shaft to
make the gap equal.
* If the gap is (-) value (drive shaft is more embossed
than idle shaft) as shown in Figure 37, combined
5mm spacer & shim(s) and add on the idle shaft to
make the gap equal.
Fig. 34
Fig. 35
Fig. 36
Summary of Contents for JEC JRZP Series
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Page 35: ...34 EXPLODED VIEW ZP030 ZP060 ZP130 ...
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