Magtrol TM 301, Руководство пользователя

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2.4 MOUNTING LIMITS
Magtrol torque sensors have been designed to accept a decent reserve for measurement over the nomi-
nal torque. They can measure up to 200% of their rated torque. It is however important not to overpassed
this limit to avoid plastic deformation and permanent deterioration of the sensor’s performances.
By sensor with very low nominal value, the installation and in particular the couplings tightening should be
done with care in order not to overload the sensor
2.4.1 DYNAMIC TORQUE
Static and dynamic measurements differ from one another by the evolution of torque over time. A constant torque
produces static measurements, whereas varying torques can only be determined by dynamic measurement.
Magtrol TM Series Torque Transducers are designed for the measurement of both static and dynamic
torque, without the need for recalibration.
2.4.2 NATURAL FREQUENCY OF DRIVE TRAIN
In order to determine the dynamic torque and frequency response, and to prevent any damage to the sys-
tem, it is necessary to calculate the natural frequency of the drive train torsional oscillations. In this system,
however, the deformation area of the measuring flange is the weakest link in the rotating measuring chain
and is subject to torsional vibrations.
In practice, this situation can generate rather complex relations which require demanding calculations.
This may be, for instance, the case for the physical model in which the drive chain is a combination of
torsion springs with intermediate flywheel masses. However, the following simplified model of a drive chain
(
see Fig.2-8
) can often be used.
. For a detailed analysis of dynamic response, publications on structural mechanics should
be consulted.
Fig.2-8 Simplified Drive Train Model
2 1
2 1
0
2
1
J J
J J
C
F
t
⋅
+
=
�
F
0
Natural frequency of system [Hz]
C
t
Measuring shaft torsional stiffness [Nm/rad]
J
1
Moment of inertia (driving m co ½ of the measuring shaft) [kgm²]
J
2
Moment of inertia (driven m co ½ of the measuring shaft) [kgm²]
NOTICE
J
1
J
2
C
t
20
TM
series
INSTALLATION / CONFIGURATION