ACCURACY IMPROVING METHOD FOR ROTARY MACHINE STATE MONITORING SYSTEM

摘要

PURPOSE:To remove the mixture of an error in measured value due to a drift, etc., by calculating the peripheral positions of a rotary shaft where the perpendicular supporting force becomes minimum/maximum, finding bearing supporting forces at positions where a specific phase is obtained based on the positions, and calculating and correcting a gap measured value. CONSTITUTION:The position of the axis of a journal shaft 1 is arranged so that the position is measured by detectors 2-1 and 2-2 such as eddy current displacement gauges based on the center CB of the bearing. After the outputs of the detectors are converted by a measuring instrument 3 into the value of the position of the axis of the journal shaft 1, a computing element 4 performs arithmetic operation to correct an error and the corrected axis position is inputted to a monitoring device 5 to monitor the state. At this time, the peripheral positions CJU and CJD of the rotary shaft where the perpendicular bearing supporting force becomes minimum/maximum are calculated, the vector sum of the supporting forces at the positions CJ1 and CJ3, and CJ2 and CJD where the specific phase is obtained is found at least twice based on both positions, and the gap measured value is calculated and corrected so that the difference between the vector sums becomes minimum.