Diagnostic method for predicting maintenance requirements in rotating equipment
First Claim
1. A diagnostic method for predicting maintenance requirements in rotating equipment normally operating in loaded and unloaded conditions, the method including the following steps;
- coupling a sensor to apparatus associated with said rotating equipment, said sensor being responsive to vibration in said apparatus to generate an electric signal;
obtaining a load signal from apparatus associated with said rotating equipment which is indicative of whether the rotating equipment is loaded;
sampling said electric signal when the rotating equipment is loaded over a predetermined sampling time interval to obtain a loaded electric signal Vl;
sampling said electric signal when the rotating equipment is unloaded over a predetermined sampling time interval to obtain an unloaded electric signal Vμ
; and
periodically displaying the relative magnitude between said loaded electric signal Vl and said unloaded electric signal Vμ
over an extended maintenance period of time, a maintenance inspection being required when the magnitude of the unloaded electric signal Vμ
exceeds the magnitude of the loaded electric signal Vl.
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Accused Products
Abstract
This invention is a method to determine the condition of rotating equipment, namely drive spindles, to enable the timely maintenance or replacement of same. The method uses an electrical signal from a vibration sensor mounted on part of the drive train to measure the level of vibration energy when the equipment is rotating under loaded and unloaded conditions. The relative vibration under the loaded and unloaded conditions is used as an indicator of equipment condition. Typically there is more vibration under load when the equipment is in good condition. When the level of vibration under the no-load condition matches or exceeds that seen under load, the equipment needs to be serviced or replaced.
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Citations
20 Claims
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1. A diagnostic method for predicting maintenance requirements in rotating equipment normally operating in loaded and unloaded conditions, the method including the following steps;
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coupling a sensor to apparatus associated with said rotating equipment, said sensor being responsive to vibration in said apparatus to generate an electric signal; obtaining a load signal from apparatus associated with said rotating equipment which is indicative of whether the rotating equipment is loaded; sampling said electric signal when the rotating equipment is loaded over a predetermined sampling time interval to obtain a loaded electric signal Vl; sampling said electric signal when the rotating equipment is unloaded over a predetermined sampling time interval to obtain an unloaded electric signal Vμ
; andperiodically displaying the relative magnitude between said loaded electric signal Vl and said unloaded electric signal Vμ
over an extended maintenance period of time, a maintenance inspection being required when the magnitude of the unloaded electric signal Vμ
exceeds the magnitude of the loaded electric signal Vl. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A diagnostic method for predicting maintenance requirements in rotating equipment normally operating in loaded and unloaded conditions, the method including the following steps;
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coupling a sensor to apparatus associated with said rotating equipment, said sensor being responsive to vibration in said apparatus to generate an electric signal; obtaining a load signal from apparatus associated with said rotating equipment which is indicative of whether the rotating equipment is loaded; calculating a range of average maximum and average minimum electric signal readings over a pre-selected sampling time interval for rotating equipment in a loaded condition; calculating a range of average maximum and average minimum electrical signal readings over a pre-selected sampling time interval for rotating equipment which is not loaded; calculating the natural log of the ratio of an average loaded to average unloaded range value to define a condition index; periodically displaying the condition index over an extended maintenance period of time, a maintenance inspection being required when the condition index falls below a predefined threshold.
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Specification