Pompa ad Ingranaggi - Serie MX
Gear Pump - MX Series
44
Exert a traction force parallel to the shaft
A, by paying attention not to scratch this last.
Make sure that grub screws
did not scratch the shaft
A.
After greasing the shaft to make assembly easier, insert the new mechanical seal by rotating
the spring in the direction opposite to that of the coil; use a pad interposed with a soft bear-
ing to press the seal up to make it match the fixed part
. Secure the ring
in the original
position and lock it on the shaft
A by using grub screws
.
During operation, pay attention not to invert seals and relevant springs.
3) Double tandem mechanical seals (see Figure 3)
a) Access to the external mechanical seal
Place a basin of suitable size and capacity under the seal cover
and, by loosening the
grub screw
, empty the tank
.
After removing the feather key
from its seat
, loosen the hexagonal head screws
of the
external seal cover
and extract this last, by paying attention not to damage the static part
of the external seal
, housed in the cover. It is thus possible to verify the state of wear and
tear of the external seal contact surfaces. On reassembly, pay attention not to pinch the
sealing O-ring
housed in the cover. Retighten the grub screw
and fill the tank
with
the recommended fluid.
b) Replacing static seals
To remove the static part of the external seal
from the seal cover
, it is necessary to ex-
tract, by using special pliers, the seeger ring
housed in the cover, remove the ball bearing
and exert a pressure upon the external side of the seal. After placing the seal cover on a
plane and greasing the walls to make assembly easier, insert the new static seal with the
relevant O-ring; use a pad interposed with a soft bearing to exert the force perpendicularly
to the cover.
To gain access to the static part of the internal seal, proceed as described at point
c)
, with-
out disassembling the dynamic part of the internal seal
. By exerting a pressure on the ex-
ternal side of the seal, remove the fixed seat of the internal mechanical seal
from the in-
ternal seal cover
B
. After placing this last on a plane and greasing the walls to make as-
sembly easier, insert the new static seal with the relevant O-ring; use a pad interposed with
a soft bearing to exert the force perpendicularly to the cover. On reassembly, pay attention
not to pinch the sealing O-ring
housed in the internal seal cover
B
.
c) Replacing dynamic seals
To remove the dynamic part of the external seal
it is advisable to hold the spring
and,
with a rotation movement in the same direction as that of its coil, exert a traction force paral-
lel to the shaft
A, by paying attention not to scratch this last. After greasing the shaft to
make assembly easier, insert the new mechanical seal by rotating the spring in the direction
opposite to that of the coil; use a pad interposed with a soft bearing to press the seal up to
make the spring rest on the external stop ring
fixed on the shaft.
To replace the dynamic part of the internal seal
, it is necessary to disassemble the ring
, secured on the shaft by means of threaded grub screws
.
We recommend to mark
accurately the ring position on the shaft before disassembly, so as to ensure the cor-
rect seal pre-load later.
Loosen the socket screws
and disassemble the internal seal
cover
B
(with the static part of the internal mechanical seal) and the O-ring
. To extract
the dynamic part of the internal seal
it is advisable to use an iron wire bent at 90° at one
end to hook the first or the second coil of the seal spring
. Exert a traction force parallel to
the shaft
A, by paying attention not to scratch this last. Ensure that grub screws
did not
scratch the shaft
A.