Simple and reliable, the torque meter measuring system is based
on the principle of a variable, torque-proportional transformer
coupling. The principle has been adapted by Magtrol for the
measurement of torque. The measuring system consists of two
concentric cylinders, shrunk on the shaft on each side of the
shaft's deformation zone, and two concentric coils attached
to the housing.
Both cylinders have a circularly disposed coinciding row of
slots and rotate with the shaft inside the coils. A constant
alternating current with the frequency of 20 kHz flows through
the primary coil. When torque is applied, the slots on the two
cylinders do not overlap. Instead, the deformation zone undergoes
an angular deformation and the slots begin to overlap. Thus,
a torque-proportional EMF is induced in the secondary coil.
The conditioning electronics convert the EMF into a voltage
between +10 and -10 V, depending on the direction of the torque.
Speed measurement is integrated by means of an inductive proximity
transducer trained on a toothed path cut directly into the outer
cylinder. Inside View of TM
Torque Transducer
