Abstract: The mounting arrangement employs a pedestal and a bearing housing which is pivotally mounted on the pedestal independently of the machine housings. The shaft ends are coupled together by a rigid coupling and are each journaled in bearings mounted within the bearing housing. The axis of the pivot bearing is horizontal and disposed in the plane of the shafts.

Abstract: A pulse generator is used to emit a pulse train of specific frequency while two pick-ups--one adjacent a circumferential array of control lugs on the rotor and the other adjacent the blades--emit start counting and stop counting pulses. The number of pulses generated by an external pulse generator are counted during the time interval for the passage of two lugs past a pick-up and the time interval for the passage of two adjacent blades past a pick-up for each revolution of the rotor. A quotient is then obtained from the two pulse numbers for each revolution and the difference between the maximum and minimum values of the quotients obtained during continued rotation is determined. If the difference exceeds a preset critical value, an activity signal is generated, for example to set off an alarm.