Method and apparatus for calibrating unbalance analyzers

Claim 1

A METHOD OF CALIBRATING A ROTATING ASSEMBLY UNBALANCE ANALYZER OF THE TYPE UTILIZED TO BALANCE A ROTATING MEMBER OF AN ASSEMBLY WHILE SAID ROTATING MEMBER IS BEING DRIVEN AT A SPEED WITHIN A SELECTED RANGE, SAID ANALYZER INCLUDING TWO VIBRATION PICKUPS FOR SENSING VIBRATIONS IN FIRST AND SECOND CORRECTION PLANES, AND CIRCUIT MEANS RESPECTIVELY RESPONSIVE TO EACH OF SAID PICKUPS FOR PRODUCING AN ELECTRICAL UNBALANCE SIGNAL TO PROVIDE AN INDICATION OF THE POSITION AND AMOUNT OF UNBALANCE IN EACH OF SAID PLANES, SAID METHOD COMPRISING THE STEPS OF ROTATING AN UNBALANCED ROTATING ASSEMBLY AT A SPEED WITHIN SAID SELECTED RANGE, GENERATING A REFERENCE SINE WAVE HAVING A FREQUENCY CORRESPONDING TO THE RATE OF ROTATION OF THE ROTATING MEMBER, SENSING THE UNBALANCE IN ONE OF SAID PLANES WITH ONE OF SAID VIBRATION PICKUPS, PRODUCING A FIRST UNBALANCE SIGNAL THEREFROM, UTILIZING SAID REFERENCE SINE WAVE TO GENERATE A FIRST CALIBRATION SIGNAL EFFECTIVE TO CANCEL OUT SAID FIRST UNBALANCE SIGNAL, VECTORIALLY ADDING SAID SIGNALS UTILIZING SAID REFERENCE SINE WAVE TO GENERATE A SECOND CALIBRATION SIGNAL EFFECTIVE TO CANCEL OUT SAID SECOND UNBALANCE SIGNAL, VECTORIALLY ADDING SAID LAST NAMED SIGNALS, THEREAFTER ADDING A KNOWN WEIGHT IN A KNOWN POSITION TO SAID ROTATING ASSEMBLY ADJACENT TO THE FIRST CORRECTION PLANE THEREOF, ROTATING SAID ASSEMBLY AND SENSING THE UNBALANCE THEREOF WITH ONE OF SAID VIBRATION PICKUPS, PRODUCING A THIRD UNBALANCE SIGNAL THEREFROM, AND ADJUSTING COMPONENTS OF SAID ANALYZER SO THAT SAID ANALYZER INDICATES THE CORRECT AMOUNT AND POSITION OF SAID ADDED WEIGHT, REMOVING SAID WEIGHT FROM THE FIRST CORRECTION PLANE, MOUNTING A KNOWN WEIGHT IN A KNOWN POSITION UPON SAID ROTATING ASSEMBLY ADJACENT TO THE SECOND CORRECTION PLANE THEREOF, ROTATING SAID ASSEMBLY AND SENSING THE UNBALANCE THEREOF IN THE SECOND CORRECTION PLANE WITH THE OTHER OF SAID VIBRATION PICKUPS, PRODUCING A FOURTH UNBALANCE SIGNAL THEREFROM, AND ADJUSTING COMPONENTS OF THE ANALYZER, WHEREBY THE ANALYZER INDICATES THE CORRECT AMOUNT AND POSITION OF THE ADDED WEIGHT IN THE SECOND CORRECTION PLANE, AND ADJUSTING COMPONENTS OF SAID ANALYZER IN A SECOND TO FIRST CROSS PLANE CIRCUIT OF THE ANALYZER IN A SECOND TO FIRST CROSS PLANE THE FRONT METER DUE TO THE SECOND TO FIRST CROSS PLANE EFFECT.