The torque motor works like a normal synchronous motor. The magnets
are fixed on the inner surface of a drum which is the driven part.
The stator consists of a large number of magnetic coils integrated
in an iron matrix. These coils are star-switched and provided with
three-phase current. The required speed is dependant on the frequency.
Because of the large number of poles high torque at very low speed
is produced. To reduce cogging to a minimum the permanent magnets
inside the rotor are fixed at an angle. No gears are needed because
the rotor is directly coupled to the shaft to be turned.
This combination is, in connection with the pre-loaded ball bearings,
absolutely free of play. Depending on the control system used, the
rigidity of the drive can be increased dramatically, combined with
higher power, precision, angular speed and acceleration.
|What is remarkable?
The torque motors are designed as outer rotors with single wound spools.
The installation space is used to full capacity in terms of torque.
The installation can be realized very easily because of its rotational
symmetry and the possibility to manufacture with turning lathes.
The characteristic design principle facilitates the integration of
powerful efficient brake. As simply shaped bushing (provided by the
manufacturer), it can be installed to the surface of the rotor.