SIEMENS
FLENDER Standard Couplings
Highly Flexible Couplings — ELPEX Series
General information
12/4
Siemens MD 10.1 · 2015
12
■
Configuration
The ELPEX coupling is especially suitable for rough opera-
tion. An application factor different from that in catalog
section 3 is therefore sufficient for all applications. In the
case of machines which excite torsional vibration, Siemens
urgently recommends carrying out a torsional vibration
calculation or measuring the coupling load occurring in the
drive.
Coupling selection
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 in driven machines:
•
uniform with moderate shock loads: generators, fans, blowers
•
non uniform: reciprocating compressors, mixers,
conveyor systems
•
very rough: crushers, excavators, presses, mills
NR: Natural rubber mixture
Coupling load at maximum and overload conditions
The maximum torque is the highest load acting on the coupling
in normal operation.
Maximum torques at a frequency of up to 25 times an hour are
permitted and must be lower than the maximum coupling torque.
Examples of maximum torque conditions are: Starting opera-
tions, stopping operations or usual operating conditions with
maximum load.
T
Kmax
≥
T
max
⋅
FT
Overload torques are maximum loads which occur only in com-
bination with special, infrequent operating conditions.
Examples of overload torque conditions are: Motor short circuit,
emergency stop or blocking because of component breakage.
Overload torques at a frequency of once a month are permitted
and must be lower than the maximum overload torque of the
coupling. The overload condition may last only a short while, i.e.
fractions of a second.
T
KOL
≥
T
OL
⋅
FT
Coupling load due to dynamic torque load
Applying the frequency factor FF, the dynamic torque load must
be lower than the coupling fatigue torque.
Dynamic torque load
T
KW
≥
T
W
⋅
FT
⋅
FF
⋅
Frequency of the dynamic torque load
f
err
≤
10 Hz frequency factor FF = 1.0
Frequency of the dynamic torque load
f
err
> 10 Hz frequency factor FF =
√
(
f
err
/ 10 Hz)
Checking the maximum speed:
The following must apply to all load situations:
n
Kmax
≥
n
max
Checking permitted shaft misalignment and restorative forces
For all load situations the actual shaft misalignment must be less
than the permitted shaft misalignment.
Checking bore diameter, mounting geometry and coupling
design
The check must be made on the basis of the dimension tables.
On request, couplings with adapted geometry can be provided.
Checking shaft-hub connection
Please refer to catalog section 3 for instructions.
Checking temperature and chemically aggressive environment
The permitted coupling temperature is specified in the Temper-
ature Factor FT table. In the case of chemically aggressive envi-
ronments, please consult the manufacturer.
Application factor FB
Torque characteristic of the driven machine
Torque characteristic
of the driving machine
uniform with
moderate shock
loads
non uniform
very rough
Electric motors,
hydraulic motors,
gas and water turbines
1.0
1.3
1.4
Internal combustion
engines
1.3
1.4
1.6
Temperature factor FT
Temperature
T
a
on the coupling
Coupling
Elastomer
material
-40 °C
to
-30 °C
-30 °C
to
+50 °C
to
60 °C
to
70 °C
to
80 °C
ELPEX
NR
1.1
1.0
1.25
1.40
1.60
Select size with:
T
KN
≥
T
N
⋅
FB
⋅
FT
0.6
FB – 1.0
© Siemens AG 2015