Device for identifying rubbing locations in rotating machines

A rubbing location identifying device for a rotating machine comprising:

• means including at least two acoustic sensors for sensing a rubbing sound produced when a rotary body comes into contact with a stationary body in a rotating machine;
• rotational pulse generating means for generating rotational pulses one for each rotation of the rotating body;
• means responsive to said acoustic sensors for determining an acoustic sound producing location in an axial direction of the rotating machine on the basis of the travelling time difference of the acoustic signals arriving at said acoustic sensors;
• memory means having a plurality of storage locations each corresponding to a respective incremental distance from a reference point on the rotating body and being responsive to the output of said determining means for storing a digital value during successive rotations of said body in those storage locations which correspond to any acoustic sound producing locations;
• and D/A converter means for D/A converting the memory content of said storage locations representative of a histogram of the number of the acoustic locations determined by said determining means, whereby an identifying signal identifying the rubbing location in the axial direction of the rotating body is obtained in synchronism with the rotational pulse signal, and thus the phase of a peak of the rubbing location identifying signal as measured with respect to the pulse interval is provided to represent an actual rubbing location.