QXT Internal Gear Flow Divider
for up to 4 outlet flows
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Reference: 100-P-000059-EN-10
Issue: 08.2021
S forupto4outletflows
S extremely high division accuracy
S exceptionally quiet operation thanks to negligible pres
sure pulsations
S long service life with low maintenance
S high efficiency, since operating principle ensures there
arenothrottlinglosses
S wide range of outlet flows are available
S suitable for special fluids such as HFC, environmentally
friendly and low viscosity fluids
1 General
1.1 Product description
Series QXT flow dividers are internal gear units that can di-
vide a flow into as many as four portions. The division ratios
are constant and are unaffected by the loads at the actua-
tors. They can be used, for example, to provide synchro-
nised movement of unequally loaded cylinders. Several hy
draulic motors can be driven at the same speed, irrespect
ive of their external loads. Since they operate on the prin
ciple of the rotating internal gear set, these flow dividers
work withoutany throttling losses, which is in strong contrast
to spool-type flow dividers. The QXT flow divider can also
be used to produce pressure intensification i.e. the outlet
pressure from the flow divider is higher than its inlet pres
sure. This takes place at high efficiency, since the operating
principle ensures that the only losses that can possibly oc
cur are proportional to the pressure difference across the
unit. The unit is based on the well-known QX internal gear
pump, which is distinguished by its very lownoise levels and
almost imperceptible pressure pulsations. The large num
ber of closely spaced sizes ensures that the right size is al
ways available for every application.
1.2 Application examples
S Air conditioning Systems
S Track laying machinery
S Waste compactors
S Hydraulic presses
S Scissor lifts
S Charge carriers
2 Symbol
p
2
/Q
2
p
1
/Q
1
p
0
/Q
0
V
1
V
2
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QXT Internal Gear Flow Divider
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3 Technical data
Characteristics Unit Description, Value
Installation attitude unrestricted
Hydraulic fluid HLP mineral oils to DIN 51524, Part 2
HFB, HFD and HFC fluids to VDMA 24317
Max admissible level of contamination of
the hydraulic fluid
ISO 4406 code 20/18/15
Operating viscosity
Starting viscosity
mm
2
/s 10 … 100 *
10 … 300 * *other values on request
Hydraulic fluid temperature °C HLP mineral oil 80°C max., HFB, HFD and HFC 50 °C max.
3.1 Flow dividers with outlet flows of equal sizes
These operating data are valid for mineral oils with 42 mm
2
/s.
Please contact Bucher if you require unequal outlet flows.
Type
Outlet
displace
ment
[
cm
3
/U
]
3)
Cont./
Interm.
pressure
1)
[
bar
]
Speed
n
max
/n
min
[
min
-1
]
Maximum inlet flow Q
0max
2 outlet flows
[l/min]
3 outlet flows
2)
[l/min]
4 outlet flows
2)
[l/min]
QXT22-005/22-005
QXT22-006/22-006
QXT22-008/22-008
5,1
6,3
7,9
250/320 6300/1250
63
80
100
95
120
150
125
160
200
QXT32-012/32-012
QXT32-016/32-016
12,6
15,6
250/320 5000/1000
120
160
180
240
240
320
QXT42-025/42-025
QXT42-032/42-032
25,1
32,3
250/320 4000/800
200
250
300
380
400
500
QXT52-050/52-050
QXT52-063/52-063
50,3
63,4
250/320 3200/630
320
400
480
600
640
800
QXT62-100/62-100
QXT62-125/62-125
100,5
124,2
250/320 2500/500
500
630
750
950
1000
1260
QXT82-200/82-200
QXT82-250/82-250
200,0
247,7
250/320 2000/400
800
1000
1200
1500
1600
2000
1) Intermittent for max. 20 sec/min but not than 10% of the duty cycle
2) for 3 and 4 outlet flow please contact Bucher Hydraulics
3) Due to manufacturing tolerances, there may be slight variations in the dis
placement.
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QXT Internal Gear Flow Divider
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3.2 Choose the optimal flow divider
These operating data are valid for mineral oils with 42
mm
2
/s.
For the highest division accuracy as well as the lowest cost,
choose the smallest possible flow divider running near its
maximum speed. The speed n in rev/min is calculated from:
Q
0
x10
3
n=
V
1
+V
2
+V
3
+...
where Q
0
= inlet flow rate in l/min and V1 = outlet displace
ment in cm
3
/rev. The minimum permissible inlet flow rate is
calculated from:
n
min
Q
0min
=
n
max
Q
0maxx
In the case of the flow dividers with unequal outlet displace-
ments, use the largest displacement for determining n
max
,
the smallest for n
min
. Since rotary flow dividers are also
pressure intensifiers, each outlet circuit must be provided
with a pressure relief valve. Bucher Hydraulics series VT re
lief valves mount directly on the flow divider and are there
fore particularly suitable (please request the data sheet
100-D-402850).
0
2
4
6
8
10
12
14
16
0,2 0,4 0,6 0,8 1,0
p = [bar]
Q
0
Q
0max
p
2
=p
1
0
4 Performance curves
These operating data are valid for mineral oils with 42 mm
2
/s.
Tests carried out on a QXT flow divider, type
32-016/32-016, produced the results shown below. For the
same speed, larger flow dividers have a better accuracy
while smaller ones display a bigger difference between the
two outlet flows. The division accuracy of the outlet flows Q1
and Q2 depends mainly on the pressure difference
between the two outlet lines and the ratio Q
0
/Q
0max
The
pressure drop across the flow divider is dependent on Q
0
/
Q
0max
Using the curves, the accuracy of flow division and
the pressure drop can be optimised.
0,60
0,55
0,50
0,45
0,40
300 bar
p
1
-p
2
0,6
0,8
1,0
0,6
0,8
1,0
0,4
0,4
Q
0
Q
0max
=0,2
Q1/Q0
Q2/Q0
Q
0
Q
0max
=0,2
100 200
p
2
0
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QXT Internal Gear Flow Divider
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5 Dimensions
5.1 For flow divider with 2 displacements
Frame size 2 3 4 5 6 8
J2 G1
1
/
4
”
thread
G1
1
/
2
”
thread
2”
SAE J518
1)
2”
SAE J518
1)
2”
SAE J518
1)
G2
1
/
2
”
thread
E G
1
/
2
”
thread
G
3
/
4
”
thread
1”
SAE J518
1)
1
1
/
4
”
SAE J518
1)
1
1
/
2
”
SAE J518
1)
2”
SAE J518
1)
G M8x12 M8x12 M10x16 M10x20 M16x28 M20x30
K2 102 129 159,5 190 230,5 282,5
L2 204 258 319 380 461 565
Z 50 60 62,5 78 97,5 125
Q2 67 87 110,5 127 149 178,5
Y 55 60 75 90 112 140
T 85 107 133 177 220 275
1) for SAE J518 code 61 / ISO 6162-1 pipe flange (see section 8.2)
5.2 Frame size 2 - 3
1
Q2 Q2
L2
Y
Z
T
K2
E
E
J2
Z
Y
1 Mounting threads
4 x dimensions 'G' - both ends
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QXT Internal Gear Flow Divider
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5.3 Frame size 4 - 6
1
T
L2
T
Q2 Q2
K2
Y
Y
E
E
J
Z Z
1 Mounting threads
4 x dimensions 'G' - both ends
5.4 Frame size 8
567
283,5
178,5
140
178,5
275
125
125
180
140
2” SAE
2” SAE
G 2 1/2”
1
1 Mounting threads
4 x dimensions 'G' - both ends
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QXT Internal Gear Flow Divider
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5.5 Flow divider with 3 displacements
(please contact Bucher Hydraulics)
E
EE
J2
J3
5.6 Flow divider with 4 displacements
(please contact Bucher Hydraulics)
E1
E2
E3
E4
J1
J2
6 Ordering code for 2 displacements
Series QXT
Framesize 2/3/4/5/6/8
Pressure range 2 2
Outlet displacement [cm
3
/U] 005 - 250 (see chapter 3.1)
Framesize 2/3/4/5/6/8
Pressure range 2 2
Outlet displacement [cm
3
/U] 005 - 250 (see section 3.1)
Option (see section 6.2)
- 1032 2 2310 2XT /-/Q
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QXT Internal Gear Flow Divider
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6.1 Ordering example
For dividers with 3 outlet flows:
QXT22-005 / 22-005 / 22-005
For dividers with 4 outlet flows:
QXT62-100 / 62-100 / 62-100 / 62-100
Flow divider combinations must contain the same frame
sizes, pressure ranges and outlet flows.
If 3, 4 or unequal flows are required, please contact Bucher
Hydraulics.
6.2 Option
-O = without priming
09 = FPM (Viton) seals and without priming
117 = port at outlet(E) in SAE J518 code 61 / ISO 6162I
at assembly group 2+3
7 Mounting instructions
Expert and product knowledge is required for the layout of
this flow divider. Use exclusively for the intended purpose
within the indicated values. The QXT manufacturer must be
consulted for use of the appliance outside the specifica
tions. All applications must be verified by sufficient tests to
ensure safety in the application. The ultimate responsibility
for safety during installation and use resides with the end
appliance manufacturer.
CAUTION:
Maintenance work may only be performed by expert per
sonnel with mechanical knowledge.
8 Accessories
8.1 Bolt-on valves - SAE J518 code 61 / ISO 6162-1 pattern
Pressure relief valve
ADF
S
G
Pressure relief valve solenoid control
ADA
S
G
Accumulator charging valve
AGSF
P
T
M
Z
P
T
M
Z
P
T
M
Z
Technical data sheet
100-P-000123
Technical data sheet
100-P-000119
Technical data sheet
100-P-0000124
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QXT Internal Gear Flow Divider
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8.1.1 Example for Bolt-on valves, mounted on QXT flow divider
Bolt-on valve with threaded ports
QXT32 + AGDF
IMPORTANT: For detailed informations on Bolt-on valves see www.bucherhydraulics.com
8.2 Pipe flange - high pressure type
- up to 420 bar
- SAE J518 code 61 / ISO 6162-1 pattern
H
E
D
G
Y
X
R
L
F
Threaded pipe flanges are spot-faced for pipe fittings.
Material: ST37 / for FPM (Viton) seals contact Bucher Hydraulics.
Order
number
Ordering
code
Size D E F H L R X Y Viton seal
90 Shore
'A'
Retaining screws
DIN912-12.9
M[Nm]
037000 RF 01-R08 G1/2” 12,5 16 27 13 54 23 17,5 38 20,24x2,62 M8x30 30
037010 RF 02-R10 G3/4” 20 18 30 12 65 26 22,2 47,6 26,65x2,62 M10x30 60
037020 RF 03-R11 G1” 25 20 34 13 70 29 26,2 52,4 32,99x2,62 M10x35 60
037030 RF 04-R12 G 1 1/4” 32 22 38 14 80 36 30,2 58,6 40,86x3,53 M10x40 60
037040 RF 05-R13 G 1 1/2” 38 24 41 19 94 41 35,7 70 44,04x3,53 M12x45 120
037050 RF 06-R14 G2” 50 26 45 20 102 48 42,9 77,8 59,92x3,53 M12x50 120
E 2021 by Bucher Hydraulics GmbH, D-79771 Klettgau
www.bucherhydraulics.cominfo.kl@bucherhydraulics.com
All rights reserved.
Data is provided for the purpose of product description only, and must not be construed as warranted characteristics in the legal sense. The
information does not relieve users from the duty of conducting their own evaluations and tests. Because the products are subject to continual
improvement, we reserve the right to amend the product specifications contained in this catalogue.
Classification: 420.245.370.
