9.1 Dimensioning the gearbox
Switching cycles can also be superimposed vibration! The supplementary factor (f2) is then
not sufficient when dimensioning the gearbox and gearboxes may fail.
The complete system should be optimized so that the higher-level vibration is minimized.
The load torque and the required start-up velocity define the gearbox output torque,
the output speed and therefore the output power.
The required drive power is calculated from this:
Dimensioning for S1 duty for non-ventilated systems
The gearbox itself generates heat due to friction and acts as a thermal barrier preventing
heat from being dissipated through the motor flange. This is the reason that the torque must
be reduced for S1 duty.
The required motor torque is calculated as follows:
Dimensioning the gearbox
[W] = P
[W] ∙ η
= (π/30) ∙ M
Calculated "torque loss"
p/3 for 1FK⃞ motors supplied with sinusoidal current
0.5 weighting factor for gearbox losses (without dimensions)
Motor speed [RPM]
Torque constant [Nm/A]
Motor phase resistance when warm [Ω] = 1.4 R
Gear drive torque [Nm]
Gearbox ratio (i > 1)
Motor power [W]
Gearbox output power [W]
Motor torque [Nm]
[Nm] ∙ n
[RPM] ∙ η
Configuration Manual, (PFK7S), Edition 12.2006, 6SN1197-0AD16-0BP1
Synchronous Motors 1FK7