SIEMENS
FLENDER Standard Couplings
Coupling Preselection and Options
Selection of the coupling size
3/6
Siemens MD 10.1 · 2015
3
■
Selection and ordering data
The torque load of the coupling must be determined from the
output of the driven machine and the coupling speed.
Rated coupling load
T
N
= 9550 ·
P
N
/
n
N
(
T
N
in Nm;
P
N
in kW;
n
N
in rpm)
The rated coupling load obtained in this way must be multiplied
by factors and compared with the rated coupling torque. An
ideal but expensive method is to measure the torque character-
istic on the coupling. For this, Siemens offers special adapters
fitted with torque measuring devices.
The rated coupling torque
T
KN
is the torque which can be trans-
mitted by the coupling over an appropriate period of use if the
load is applied to the coupling purely statically at room temper-
ature.
Application factors are to express the deviation of the real cou-
pling load from the "ideal" load condition.
Coupling load in continuous operation
The operating principles of the driving and driven machines are
divided into categories and the application factor FB derived
from these in accordance with DIN 3990-1.
Examples of torque characteristic of driving machines:
•
uniform: Electric motors with soft starting, steam turbines
•
uniform with moderate shock loads: Electric motors without
soft starting,
hydraulic motors, gas and water turbines
•
non uniform: Internal-combustion engines
Examples of torque characteristic in driven machines:
•
uniform: Generators, centrifugal pumps for light fluids
•
uniform with moderate shock loads: Centrifugal pumps for
viscous fluids, elevators, machine tool drives, centrifuges,
extruders, blowers, crane drives
•
non uniform: Excavators, kneaders, conveyor systems,
presses, mills
•
very rough: Crushers, excavators, shredders,
iron/smelting machinery
NR
= natural rubber, natural-synthetic rubber mixture
NBR
= nitril-butadiene-rubber (Perbunan)
HNBR = hydrated acrylonitrile butadiene rubber
CR
= chloroprene rubber (FRAS fire-resistant and anti-static)
VMQ
= silicone
TPU
= polyurethane
In the case of ARPEX and ZAPEX coupling types, no temper-
ature factor (FT = 1.0) need be taken into account.
Application factor FB
Torque characteristic of the driven machine
Torque characteristic of
the driving machine
uniform
uniform
with
moderate
shock loads
non
uniform
very rough
uniform
1.0
1.25
1.5
1.75
uniform with moderate
shock loads
1.25
1.5
1.75
2.0
non uniform
1.5
1.75
2.0
2.5
Temperature factor FT
Temperature
T
a
on the coupling
Coupling
Elastomer
material
Low temperature
°C
under
-30 °C
-30 °C
to
50 °C
to
60 °C
to
70 °C
to
80 °C
to
90 °C
to
100 °C
to
110 °C
to
120 °C
N-EUPEX
NBR
-30
–
1.0
1.0
1.0
1.0
–
–
–
–
N-EUPEX
NR
-50
1.1
1)
1.0
–
–
–
–
–
–
–
N-EUPEX
HNBR
-30
–
1.0
1.0
1.0
1.0
1.25
1.25
–
–
N-EUPEX DS
NBR
-30
–
1.0
1.0
1.0
1.0
–
–
–
–
RUPEX
NBR
-30
–
1.0
1.0
1.0
1.0
–
–
–
–
RUPEX
NR
-50
1.1
1.0
1.0
–
–
–
–
–
–
RUPEX
HNBR
-30
–
1.0
1.0
1.0
1.0
1.25
1.25
–
–
N-BIPEX
TPU
-50
1.0
1.0
1.0
1.0
1.0
1.0
1.0
–
–
ELPEX
NR
-40
1.1
1.0
1.25
1.40
1.60
–
–
–
–
ELPEX-B
NR
-50
1.1
1.0
–
–
–
–
–
–
–
ELPEX-B
CR
-15
–
1.0
1.0
1.0
–
–
–
–
–
ELPEX-S SN, NN, WN
NR
-40
1.1
1.0
1.25
1.40
1.60
–
–
–
–
ELPEX-S NX
VMQ
-40
1.1
1.0
1.0
1.0
1.0
1.1
1.25
1.4
1.6
Coupling size
T
KN
≥
T
N
· FB · FT
1)
The N-EUPEX coupling is not suitable for shock loads when used at low
temperatures.
© Siemens AG 2015