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5) Disassemble the coupling screws between the pump head bracket and the transmission box body, pull out the
bracket horizontally.
6) Pull out the arch prop 2 from the front of the box body, then complete the disassembly.
5.2.3Reassembly of the transmission box
Clean and inspect all parts before assembly, and replace new parts for worn-out parts that cannot be repaired.
Reassemble the transmission box in the reverse sequence according to the disassembly sequence. Please pay attention
to the following things:
1) When installing or replacing a new worm or a worm gear, please re-measure and re-adjust the meshing center
position of the worm gear and the worm. The correct meshing position should be: the center of the worm and
the center plane of the gorge circle of the worm gear is on the same central plane. The adjusting method is as
follows: apply a thin layer of red lead on the working teeth surface of the worm gear, rotate it several times with
the hand, observe the position of the meshing point, and increase or decrease the thickness of sealing paper pad
on the bottom bearing seat to make the meshing point reach the correct position.
2) Because the movement of the metering pump bears the alternating load, the wear of the load on the worm gear
in discharge stroke is greater than the suction stroke. Therefore, when disassembling the pump for inspection,
according to the worn-out degree of the worm gear teeth, the worm gear can be rotated 180 degrees around the
axis relative to the original assembly position and then installed back, so as to prolong the service life of the
worm gear.
3) When installing back the cross head and the oil seal of the cross head, pay attention to observe that there should
be no scratch and damage on the surface of the cross head, otherwise it will affect the sealing effect of the
isolation between the transmission box and the bracket.
4) After all parts of the transmission box are assembled and restored by the reverse sequence method, check the fan
blades of the motor first, and the fan shall be rotated freely without any jamming. While moving the impeller of
the motor, turn the adjusting handwheel outward (away from the box body); when the pump stroke being
adjusted to 0 position (i.e., the cross head is fixed), install and adjust the scale on the dial to the 0 position, and
then lock and adjust the handwheel fixed screw.
