SIEMENS
9
Siemens MD 10.3 · 2015
FLENDER Standard Couplings
Torsionally Rigid Couplings – SIPEX Series
Technical information
■
Overview
Coupling dimensioning
Dimensioning according to torque
It must be ensured that the coupling is capable of safely trans-
ferring peak torques that regularly occur at the drive or load end.
The service factor is provided in order to describe the deviation
between the real coupling load and ideal load conditions:
T
KN
≥
T
AS
×
FB
or
T
LS
×
FB
Dimensioning according to acceleration torques
The correct coupling size can be calculated more accurately on
the basis of acceleration or deceleration torques because the
peak torque at the coupling is reduced by the ratio between the
moments of inertia on the drive and load ends:
T
KN
≥
T
S
×
FB
Checking the maximum torsion angle
If the application requires a maximum torsion angle of the cou-
pling, the selected coupling size must be checked to ensure that
it is sufficiently torsionally rigid for the application in question:
Checking the maximum speed
For all load situations
n
Kmax
>
n
max
Checking the permitted shaft misalignment
The actual shaft misalignment must be less than the permitted
shaft misalignment for all load situations.
Checking the shaft-hub connection
In the case of clamping connections without feather key, it must
be ensured that the transmissible torque of the hub connection
is greater than the peak torque at the coupling.
Formula symbols
Key to formula symbols
Torque characteristic of drive
Service factor FB
Uniform
1.5
Non Uniform
2
Rough
2.5 - 4
Servomotors (machine tools)
1.5 - 2
T
S
T
AS
J
L
J
A
J
L
+
-------------------
×
or
T
S
T
LS
J
L
J
A
J
L
+
-------------------
×
=
=
ϕ
180
π
---------
T
S
C
Tdyn
----------------
×
=
Name
For-
mula
symbol
Unit
Explanation
Rated coupling
torque
T
KN
Nm
Torque which can be transmitted as
static torque by the coupling
over the period of use.
Coupling overload
torque
T
KOL
Nm
Torque which can be transmitted
very rarely as maximum torque by
the coupling.
Peak torque at
drive end
T
AS
Nm
Peak torque during non-periodic
torque surges at drive end
Peak torque at load
end
T
LS
Nm
Peak torque during non-periodic
torque surges at load end
Peak torque
T
S
Nm
Peak torque at the coupling
Service factor
FB
Factor that expresses the real cou-
pling load as a ratio of the nominal
coupling load
Moment of inertia of
drive end
J
A
kgm
2
Sum of the moments of inertia at the
drive end referred to the coupling
speed
Moment of inertia of
load end
J
L
kgm
2
Sum of the moments of inertia at the
load end referred to the coupling
speed
Torsion angle
ϕ
°
Torsion angle of the coupling under
torsional load
Torsional stiffness,
dynamic
C
Tdyn
Nm/rad
Dynamic torsional stiffness of the
coupling
Axial stiffness
C
a
N/mm
Axial stiffness of the coupling
Radial stiffness
C
r
N/mm
Radial stiffness of the coupling
Rated speed
n
N
rpm
Coupling speed
Maximum coupling
speed
n
Kmax
rpm
Maximum permissible coupling
speed
Axial misalignment
Δ
K
a
mm
Axial misalignment of the coupling
halves
Radial misalign-
ment
Δ
K
r
mm
Radial misalignment of the coupling
halves
Angular misalign-
ment
Δ
K
w
°
Angular misalignment of the coupling
halves
© Siemens AG 2015