Technical data

9.7 Bearing and Shaft Load
9.7.1 General
During operation, both radial and axial forces act upon the motor shaft and the
motor bearings. The construction of the machine, the selected motor type and
the attachment of driving elements on the shaft side must be adapted to one
another to ensure that the load limits specified are not exceeded.
9.7.2 Radial Load, Axial Load
Fig.9-15: Example of a shaft load diagram
The maximum permissible radial force F
radial_max
depends on the following fac-
tors:
● Shaft break load
● Point of application of force x (see chapter „Technical Data“)
● Shaft design (plain; with keyway)
The permitted radial force F
radial
depends on the following factors:
● Arithmetic mean speed (n
mittel
)
● Point of application of force x (see chapter „Technical Data“)
● Bearing Lifetime
The maximum permitted axial force F
axial
is proportional to the radial force. The
maximum permitted axial force F
axial
is specified in the Technical Data, in the
”Shaft load” section.
The initialization and deceleration times can be ignored in the calculation if the
time in which the drive is operated at a constant speed is significantly greater
than the acceleration and deceleration time. In the exact calculation of the mean
speed according to the following example, the run-up and braking times are
taken into account.
Maximum permitted radial force
Permittable radial force
Permittable axial force
Mean speed
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Operating Conditions and Application Notes