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8/13/2019 Piston Pump b737
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Vickers®
Engine-Driven Pump for Boeing's B737-600/700/800/900P/N 849589Model PV3-240-18
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2 EATON Aerospace Group TF500-23A October 2013
Eaton’s Vickers® part number
849589 (model PV3-240-18)
main Engine-Driven Pump (EDP)was specifically designed to
meet the requirements of the
Boeing 737-600/700/800/900
aircraft. This state-of-the-art
engine-driven pump offers
superior performance, higher
horsepower to weight ratio,
and lower operating costs.
It delivers 37.5 gpm (142 L/min)
at 3750 rpm and a 2850 psi
(19651 kPa). The design of the
pump is drawn from Eaton’s
Vickers product line of highly
reliable 2.40 cu/in displacement
pumps and has significant
reduction in weight and volume.
Model PV3-240-18 incorporates
the field proven, reliable model
PV3-240-2 and -10 pump
rotating components together
with improved reliability and
weight reduction technology
developed from the B777
engine-driven pump program.
Many piece parts from thecurrent model PV3-240
production models are
incorporated in the new unit,
which reduces spare parts
inventory requirements.
DESIGN FEATURES
Model PV3-240-18 incorporates
numerous design features to
improve the reliability and
maintainability of the unit.
Increased Fatigue Strength
All castings are designed for
improved fatigue characteristics
through specific structural
design based on finite element
analysis and use of improved
casting materials.
Proven Shaft and Yoke
Bearings
All bearings used in modelPV3-240-18 EDP carry the
same part numbers as model
PV3-240 series. This will
reduce spare parts inventory.
Hollow Drive Shaft
The drive shaft is hollow for
weight reduction. The internal
surface created by the weight
reduction is coated for
corrosion control.
Improved Cylinder Block
MaterialThe cylinder block is machined
from ductile iron to minimize
wear in the drive spline and
piston bores. Bronze plating
on the cylinder block surface
provides a durable bearing
surface for wear against the
tool steel valve plate.
Proven Yoke Design
The yoke used in model
PV3-240-18 is an exact “mirror
image” of the field provenmodel PV3-240-10 series yoke.
This is due to the fact that
model PV3-240-18 is a counter
clockwise rotation unit in the
Boeing 737-600/700/800/900
application. All material strength
requirements are identical. The
design allows for the use of
mid-grip helical thread locking
inserts. This eliminates the
need for time consuming safety
wiring of the shoe retaining
plate threaded fasteners.
Sleeved Actuator Piston Bore
A removable AISI 52100
bearing quality steel provides
the bearing surface for the
actuator piston.
Balanced Blocking ValveThe outlet blocking valve is
hydraulically balanced for rapid
response and ease of manufac-
ture. Viscous dampening of the
blocking valve piston retards
the closure rate to allow suffi-
cient decompression time for
the system outlet fluid prior to
valve closure.
Pressure Compensator
Stepped diameter seal glands
simplify assembly/disassembly
and minimize the risk of seal
damage. Double back-up rings
provide improved seal support
under high pressure condi-
tions. The pressure compen-
sator design also incorporates
viscous dampening to improve
dynamic stability.
Centrifugal Boost Impeller
Swept blade boost impeller
provides higher flow capability,
allowing for a smaller size
impeller.
Flange Mounted Electrical
Depressurization Valve (EDV)
The EDV is flange mounted
using two (2) threaded
fasteners. Step diameter seal
glands reduce the possibility
of seal damage during
assembly.
Removable Valve Plate
Separable valve plate design
allows for ease of assemble and
optimized material selection.
Single-piece Housing
The single-piece housing
design simplifies maintenance
tasks, reduces package
weight, and minimizes
envelope requirements. Most
importantly, it eliminates the
parting line between the
housing and the valve block.
Leakage from the high
pressure parting line seals at
this interface has traditionally
been one of the highest
causes of removal of model
PV3-240-2 and -10 series units.
Part Commonality
Model PV3-240-18 design
utilizes many parts common to
other Eaton models. This will
reduce the operators’ sparepart stock requirements.
Engine-Driven Pump Model PV3-240-18
Boeing 737
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EATON Aerospace Group TF500-23A October 2013
BASIC PUMP OPERATION
The aircraft’s engine rotates
the pump drive shaft, and the
connected cylinder block and
pistons. Pumping action is
generated by piston shoes
which are restrained and slide
on the shoe bearing plate in
the yoke assembly. Because
the yoke is at an angle to the
drive shaft, the rotary motion
of the shaft is converted to
piston reciprocating motion.
As the piston begins to withdraw
from the cylinder block,
system inlet pressure forces
fluid through a porting arrange-
ment in the valve plate into
the cylinder bore. The piston
shoes are restrained in the
yoke by a piston shoe retaining
plate and hold-down retainer
during the intake stroke.
As the drive shaft continues to
turn the cylinder block, the
piston shoe continues
following the yoke bearingsurface. This begins to return
the piston into its bore, toward
the valve block.
The fluid contained in the bore
is precompressed then
expelled thought the valve
block outlet port. Discharge
pressure holds the piston shoe
against the yoke bearing
surface during the discharge
stroke and also provides the
shoe pressure balance and
fluid film through on orifice in
the piston and shoe
sub-assembly.
Engine-Driven Pump Model PV3-240-
Typical Pump Characteristics
A representative speed of 3750 rpm was used in developing curves
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4 EATON Aerospace Group TF500-23A October 2013
Engine-Driven Pump Model PV3-240-18
With each revolution of the
drive shaft and cylinder blockeach piston goes through the
pumping cycle described
above, completing one intake
and one discharge stroke.
High-pressure fluid is ported
past the blocking valve to the
pump outlet. The blocking
valve is designed to open and
remain open during normal
pump operation.
Internal leakage keeps the
pump housing filled with fluid
for lubrication of rotating parts
and cooling. The leakage is
returned to the system
through a case drain port. The
case relief valve protects the
pump against excessive case
pressure, relieving it to the
pump inlet.
CONTROL FEATURES
Normal Pumping Mode
The pressure compensator is a
spool valve that is held in the
closed position by an adjustable
spring load. When pump outlet
pressure (system pressure)
exceeds the pressure setting,
3025 psi (20857 kPa), and the
spool moves to admit fluid
from the pump outlet into the
actuator piston. (In the
schematic on page 5, the
pressure compensator is
shown at cracking pressure,
i.e., pump outlet pressure just
high enough to move the
spool to begin to admit fluid to
the actuator piston.)
At pump outlet pressures
below 3025 psi (20857 kPa), itis held at its maximum angle
in relation with the drive shaft
centerline by the force of the
yoke return spring. Decreasing
system flow demand causes
outlet pressure to become
high enough to crack the
compensator valve open and
admit fluid to the actuator
piston. This control pressure
overcomes the yoke return
spring force and strokes the
pump yoke to a reducedangle. The reduced angle of
the yoke results in a shorter
stroke for pistons and
reduced displacement.
The lower displacement
results in a corresponding
reduction in pump flow. The
pump delivers only that flow
required to maintain the
desired pressure in the
system. When there is no
demand for flow from the
system, the yoke angle
decreases to nearly zero
degrees stroke angle. In this
mode, the unit pumps only its
internal leakage.
Thus, at pump outlet pressure
above 3025 psi (20857 kPa),
pump displacement decreases
as outlet pressure rises. At
system pressure below this
level, no fluid is admitted
through the pressure
compensator valve to theactuator piston and the pump
remains at full displacement,
delivering full flow. Pressure is
then determined by thesystem demand.
Depressurized Mode
When the solenoid valve is
energized, outlet fluid is ported
to the EDV control piston on
the end of the compensator.
The high pressure fluid pushes
the compensator spool beyond
its normal metering position.
This removes the compensator
from the circuit, and connects
the actuator piston directly tothe pump outlet.
Outlet fluid is also ported to
the blocking valve spring
chamber. This equalizes
pressure on both sides of the
blocking valve causing it to
close due to the force of the
blocking valve spring. This
isolates the pump from the
external hydraulic system.
The pump strokes itself to
zero delivery at an outlet
pressure that is equal to the
pressure required on the
actuator piston to reduce the
yoke angle to nearly zero. This
depressurization and blocking
feature can be used to reduce
the load on the engine during
start-up and, in a multiple
pump system, to isolate one
pump for check out purposes.
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EATON Aerospace Group TF500-23A October 2013
Engine-Driven Pump Model PV3-240-
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6 EATON Aerospace Group TF500-23A October 2013
Engine-Driven Pump Model PV3-240-18
DISPLACEMENT
CU IN / REV
RATED
SPEED
(RPM)
3750
RATED INLET
PRESSURE
(PSIA)
3
@ 6 GPM
RATED DISCHARGE
PRESSURE
RATED
DELIVERY
RATED INLET
TEMPERATURE
225ºF
(107.2ºC)
FLUID
BMS-3-11
MAXIMUM
WET WEIGHT
PV3-240-18A AND
PV3-240-18 MOD. A
MAXIMUM
WET WEIGHT
PV3-240-18 AND
PV3-240-18 MOD. B
10.76(273.30)
5.54
(140.71)
3.06(77.72)
.443 (11.25)
9.36 (237.74)
7.62 (193.54)
32.9 LBS
(14.92 KG)
32.0 LBS
(14.51 KG)37.5 GPM
(142 L/M)2.403025 PSIG
(2087 KPA)
1.81(45.97)
Dimensions shownin inches (mm)
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EATON Aerospace Group TF500-23A October 2013
5.0(127.0)
.143 (10.49)
.750 (19.04) .094 (2.387)
.60 (15.23)4.87 (123.69) MAX
.90 (22.86)
3.14
(79.75)
2.05
(52.09)
.49
(12.44)
.27
.07
(6.85)
(1.77)
4.5 (114.30)
4.3 (109.21
2.96
(75.18)
2.32
(58.92)
.11 (2.79)
.34 (8.6
.14 (3.5
Engine-Driven Pump Model PV3-240-
Dimensions shownin inches (mm)
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Copyright © 2013 EatonAll Rights ReservedForm No. TF500-23A(Supersedes PN140-13)October 2013
EatonAerospace Group9650 Jeronimo RoadIrvine, California 92618Phone: (949) 452 9500Fax: (949) 452 9990www.eaton.com/aerospace
EatonAerospace GroupFuel & Motion Control Systems Division5353 Highland Drive
Jackson, Mississippi 39206-3449Phone: (601) 981 2811Fax: (601) 987 5255