8. Regulating Linkage
HELENOS III
14
7. Actuators
7.1. Design and Mode of Operation
feedback probe
feedback cam
governor output shaft
gearbox
dc disk armature
motor
Fig. 9: Sectional Drawing of Actuator
The actuator torque is generated by a DC disk armature motor and transmitted to the
governor output shaft by way of a gearbox.
The use of special materials and long-time lubricants assures maintenance-free operation
and long working life of the actuators.
A feedback cam is mounted on the governor output shaft which is scanned contactlessly by
a probe, thus transmitting the precise position of the output shaft to the control unit.
If the actuator strikes against a stop, as may occur, e.g., under parallel mains operation or
may be caused by engine overload or cylinder failure, the current limitation will take effect
after approx. 20 seconds; by this the current to the actuator is reduced to a value that
cannot harm the motor.
