SIEMENS
FLENDER Standard Couplings
Fluid Couplings — FLUDEX Series
13/9
Siemens MD 10.1 · 2015
General information
13
FN series – drive via the housing
FLUDEX FN series couplings have a larger delay chamber than
the FV series. The delay chamber is designed as a hub carrier
(120) and is mounted on the motor shaft. The hub carrier is
flange-fitted to the housing (101, 102) of the FLUDEX coupling.
Output is via the blade wheel (105) and the shaft (106) to the
flexible N-EUPEX coupling connecting to the gear unit or driven
machine. With types FND, FNDB and FNDS the coupling can be
dismounted radially without moving the coupled machines.
Because of the larger delay chamber, FN couplings enable even
softer starting than FV couplings. Torque limitation during motor
starting is approx. 1.3 times
T
N
. A further advantage of types
FNDB and FNDS is the favorable weight distribution.
The normally stronger motor shaft bears the weight of the hub
carrier (cast version) and the main coupling. The gear unit shaft
carries only the brake drum or disk and the output-side part of
the flexible coupling. At the same time, the principle of the drive-
side delay chamber with the capacity for increasing torque time-
dependently is retained. FN couplings have the same fields of
application as FV couplings. However, they offer special advan-
tages in the brake disk design because of the weight distribu-
tion.
Depending on the series selected, different starting characteristics arise during starting.
FLUDEX series:
2/3
10
12
11
32
101
102
103
105
106
120
153
173
163
103
101
153
173
102
105
2/3
10
12
11
32
163
106
120
FND
FNDB
G_MD10_EN_00118
Part 2/3 of the flexible coupling
Part 10 of the flexible coupling
Flexible elements
Part 11
Brake drum
Blade wheel (outer wheel)
Cover
Fusible safety plug
Blade wheel (inner wheel)
Shaft
Hub carrier (large delay chamber)
Filler plug
Oil locking screw - delay chamber
Screw plug (oil drain)
Working chamber
Damming chamber
Large delay chamber
G_MD10_EN_00120b
T
coupl
0.0
0.5
1.0
1.5
2.0
2.5
Coupling torque over starting time
Starting time
FA.. / FG..
FV..
FN..
G_MD10_EN_00119a
0.0
0.5
1.0
1.5
2.0
2.5
Motor torque/coupling torque
Motor speed
Torque
n
0
n
1
T
T
0%
50%
100%
N
/
Mot
T
/
s = 100% - FN..
s = 100% - FV.
s = 100% - FA.. / FG..
Series
Description
FA../FG..
Basic coupling without delay chamber
FV..
Coupling with delay chamber
FN..
Coupling with large delay chamber
© Siemens AG 2015