TM 9-3418-201-14&P
OPERATION
Operation: Pumping is performed by cartridges
good quality, high temperature, bearing grease.
consisting of a ring,' rotor, two bushings, twelve vanes
CAUTION
and a locating pin or screws (see figure 2). The splined
Over-lubrication can damage the shaft seal.
pump shaft rotates driving a slotted rotor. Vanes within
the rotor slots are thrown out by centrifugal force and
Routine Inspection and Maintenance:
held out by system pressure to follow a double lobed
Make certain all hydraulic connections are tight
cam ring. Movement of the vanes in and out as they
a.
follow the cam causes the chambers between them to
to prevent fluid leakage or entry of air into the system.
increase in size and pick up fluid from the reservoir as
the vanes cross the inlet porting.
Chamber size
b.
Check fluid level in the reservoir to assure an
decreases when the vanes cross the outlet porting
adequate supply to the pump intake. When adding fluid,
forcing fluid out into the system.
always pour it through a 200 mesh or finer screen.
The size of the cartridge ring determines the pump
c.
Inspect the filter element and replace if dirty.
displacement. Ring change alters delivery. However,
the 11 gpm ring in the small series and the 36 gpm ring
d.
If
in the intermediate series are used with wide vanes and
contaminated, drain the system and thoroughly clean the
rotor so conversions
to these capacities require
reservoir. Change the filters and flush the complete
additional change of rotor, vanes and head.
system with clean fluid. Again drain the system and refill
with new fluid.
Lubrication: None is required for current design models.
Older designs require lubrication of the front shaft
e.
Check the reservoir air breather and replace if
bearing. A grease fitting is provided on top the pump
dirty.
body. (Some of the larger pumps also incorporate a
grease relief fitting on the bottom of the body.) It is
recommended that these fittings be lubricated sparingly
(approximately one tablespoonful every six months) with
a low pressure gun using a
OVERHAUL
Complete overhaul may be accomplished by means of
Remove light scores by lapping; replace if heavily
cartridge and gasket kits.
scored. Stone new parts lightly to remove burrs.
d.
Bearings for cracked or pitted races or pitted
Disassembly may be accomplished in the order shown
balls. Replace if defective.
in the illustration (see figure 3 or 4).
e.
Shaft for wear at seal lip journal. Replace if
WARNING
scored.
Before breaking any circuit connections,
f.
Replace shaft seal, 0 ring and head packing at
be certain the electrical power is off and
each teardown.
the system is relieved of trapped
pressure.
Reassembly: Assemble parts in reverse order of
Prepare a clean, lint-free surface on which to lay internal
disassembly, noting the following:
parts of the pump. Thoroughly clean areas adjacent to
a.
Assemble seals with spring toward inside of the
the components being removed to minimize possibility of
pump.
dirt entering the system. Cap or cover all exposed ports
b.
Coat all parts with compatible fluid and lightly
and openings into the system.
lubricate the lip of the shaft seal to prevent damage
during installation.
Inspect and replace as follows:
c.
Install bearing and snap ring on shaft end and
place in the body.
a.
Vanes, for wear and sticking in rotor slots.
d.
Spring in the shaft seal must be toward the shaft
Vanes must move in slots from their own weight when
bearing.
dry. Replace if defective. Stone new vanes lightly on an
e.
Install cartridge parts so arrows on the parts are
India stone to remove sharp edges.
pointed for intended rotation as viewed from the shaft
b.
Ring, for scored or cross-grooved cam face.
end.
Replace if grooved or scored.
f.
Assemble the pin so its small diameter end fits
into the body for RH rotation (large end in body for LH
Faces of rotor and bushings for wear and scoring.
rotation). See installation page 23.
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