Siemens SINAMICS S120 Configuration Manual page 31

Calculating the belt pre-tension force F
F
R
Table 2-6
Formula abbreviations
F
R
M
0
c
d
R
When using other configurations, the actual forces that generated from the torque being
transferred must be taken into account.
Axial force stressing
Warning
Motors with integrated holding brake cannot be subject to axial forces!
When using, for example, helical toothed wheels as drive element, in addition to the radial
force, there is also an axial force on the motor bearings. For axial forces, the spring-loading
of the bearings can be overcome so that the rotor moves corresponding to the axial bearing
play present (up to 0.2 mm). A special bearing is required for this. For use of special
bearings, contact your Siemens representative.
The permissible axial force can be approximately calculated using the following formula:
F = 0.35 • F
A
Synchronous Motors 1FK7
Configuration Manual, (PFK7S), Edition 12.2006, 6SN1197-0AD16-0BP1
R
[N] = 2 • M • c / d
0 R
Explanation of the formula abbreviations
Unit
N
Nm
–––
m
Q
F ≤ F
R Qperm
Description
Belt pre-tension
Motor static torque
Pre-tensioning factor; the pre-tensioning factor is
an empirical value from the belt manufacturer.
It can be assumed as follows:
for toothed belts: c = 1.5 to 2.2
for flat belts c = 2.2 to 3.0
Effective diameter of the belt pulley
Application
2.1 Environment
31