Installation and Operational Instructions for
ROBA
®
-ES Couplings Type 94_._ _ _._ Sizes 14
– 65
(B.9.6.EN)
11/03/2022 TK/GH/GC/MD
Chr. Mayr GmbH + Co. KG
Eichenstraße 1, D-87665 Mauerstetten, Germany
Phone: +49 8341 804-0, Fax: +49 8341 804-421
Page 25 of 29
ROBA
®
-ES Coupling Dimensioning
1.
Approximate calculation of the coupling torque:
1.1.
T
N
from the nominal power
T
N
=
9550 x P
AN/LN
n
1.2.
Dynamic torques T
S
and T
W
(5.1 and 5.2):
Drive-side excitation:
Output-side excitation:
Peak torque:
T
S
= T
AS
x
J
L
J
A
+ J
L
x S
A
Peak torque:
T
S
= T
LS
x
J
A
J
A
+ J
L
x S
L
Alternating torque:
T
W
= T
AW
x
J
L
J
A
+ J
L
x V
R
Alternating torque:
T
W
= T
LW
x
J
A
J
A
+ J
L
x V
R
2.
Comparison of torques occurring in the coupling with the permitted torques
The coupling must be dimensioned so that the loads occurring do not exceed the permitted values in any operating condition.
2.1.
Load due to nominal torque
T
KN
≥ T
N
x S
δ
2.2.
Load due to torque impacts (5.3)
T
K max
≥ T
S
x S
Z
x S
δ
+ T
N
x S
δ
2.3.
Load due to resonance passing through (5.4)
T
K max
≥ T
S
x S
Z
x S
δ
x V
R
+ T
N
x S
δ
2.4.
Load due to constantly alternating torque
– cycle operation (5.5 and 5.6)
Permitted alternating torque on coupling:
T
KW
= 0.25 x T
KN
(for aluminum hubs)
T
KW
= 0.35 x T
KN
(for steel hubs)
T
KW
≥ T
W
x S
δ
x S
f
3.
Inspection of permitted misalignments
∆K
a
≥ ∆W
a
x S
δ
∆K
r
≥ ∆W
r
x S
δ
x S
n
∆K
w
≥ ∆W
w
x S
δ
x S
n
If more than one kind of misalignment occurs at the same time, please observe Fig. 16 (page 19).
4.
Frictional locking inspection on hub connection
T
R
> T
max
: T
max
is the maximum torque occurring in the coupling.
Values for T
R
are on pages 5 to 10.
5.
Explanations
5.1. The torque determination on the coupling is applicable if the shaft coupling in the system is the torsionally softest element,
and therefore the system can be considered as a double-mass oscillator. If this is not the case, the calculation of the torque on
the coupling requires a more detailed calculation procedure.
5.2. The impact factors S
A
/ S
L
describe the impact progression. A rectangular progression of the peak torque is the heaviest impact
(S
A
/S
L
= 2.0). A flat sinus progression of the peak torque is a light impact (S
A
/S
L
= 1.2).
5.3. T
S
, the peak torque in the coupling, is the maximum torque on the coupling during the impact
minus the system torque having an effect on the coupling during normal operation.
T
S
= T
max, impact
- T
N
5.4. If a drive is operated supercritically, meaning that the operating speed n lies above the resonance speed n
R
, then resonance
passing through causes particular loads.
If the resonance passes through quickly below the operating speed, only a few resonance peaks occur. The alternating torque
in resonance can therefore be compared to the maximum torque on the coupling (see also 5.6).
5.5. S
f
takes the frequency dependency of lifetime into account. The frequency dependency is first taken into account above 5 Hz.
5.6. On appreciable vibration excitation, the resonance must be moved out of the operating range by selecting a suitable torsional
spring rigidity of the coupling.