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US 10,168,248 B1Granted
Vibration measurement and analysis
AssigneeTensor Systems Pty Ltd
InventorsJohn Adrian Morey, James Edward Steward
Life of this patent
Estimating the term…
Abstract
A method of measuring and analyzing vibrations of a mechanical system, e.g., for performing gear and bearing fault detection within a system having a reference shaft and a plurality of rotating components. The method may include the steps of tabulating gear ratios of the plurality of rotating components relative to the reference shaft in integer form, establishing a measurement specification and communicating the measurement specification to a digitizer, recording vibration data from the mechanical system during operation, and resampling the recorded vibration data using the tabulated gear ratios to obtain vibration data corresponding to the rotating components and a vibration signature for a component of interest at predetermined angular increments.
Claims20
A method of measuring and analyzing vibrations of a mechanical system having a reference shaft and a plurality of rotating components, including the steps of:
- tabulating in a specification table, gear ratios of the plurality of rotating components relative to the reference shaft in integer form;
- establishing a measurement specification and communicating the measurement specification to a digitizer, the measurement specification including a sample rate at which vibration data is to be recorded and operating conditions of the mechanical system that are to be met before vibration data pertaining to the mechanical system is recorded;
- recording data from the mechanical system during operation, the data comprising rotational speed of the reference shaft received from a first sensor operatively coupled to the reference shaft and vibration data received from one or more vibration sensors operatively coupled to one or more of the reference shaft and the plurality of rotating components;
- and
- resampling the recorded vibration data using the gear ratios defined in a specification table to obtain vibration data corresponding to the plurality of rotating components or each of the plurality of rotating components,
- wherein from the step of resampling there is obtained for analysis a vibration signature for a component of interest at predetermined angular increments,
- wherein the step of resampling includes resampling sampled time-domain signal data to generate resampled signals with a fixed number of data points per revolution of a shaft to be analyzed, and
- wherein the resampling is performed by:
- applying a cubic Hermite spline function to a position map of the reference shaft to produce a series of resample time instants within an interval of one revolution of a shaft to be analyzed, from a set of values obtained from measured signal values obtained over a plurality of revolutions of the shaft to be analyzed;
- and
- interpolating a resampled signal value at each of the resample time instants.
8 more elements
A method of measuring and analyzing vibrations of a mechanical system having a reference shaft and a plurality of rotating components, including the steps of:
- tabulating, in a specification table, gear ratios of the plurality of rotating components relative to the reference shaft in integer form;
- establishing a measurement specification and communicating the measurement specification to a digitizer, the measurement specification including a sample rate at which vibration data is to be recorded and operating conditions of the mechanical system that are to be met before vibration data pertaining to the mechanical system is recorded;
- recording data from the mechanical system during operation, the data comprising rotational speed of the reference shaft received from a first sensor operatively coupled to the reference shaft and vibration data received from one or more vibration sensors operatively coupled to one or more of the reference shaft and the plurality of rotating components,
- wherein the step of recording vibration data includes a subroutine for checking operation of sensors within predetermined operating conditions, the subroutine including the steps of:
- integrating an acceleration waveform of the recorded vibration data to velocity to amplify transient oscillations of the acceleration waveform;
- filtering the velocity waveform in the time domain using a two pole Butterworth filter or a drift filter to reduce resulting transients;
- applying a damped exponential filter function to further remove transients;
- and
- differentiating the velocity waveform to return it to an acceleration waveform;
- and
- resampling the recorded vibration data using the gear ratios defined in the specification table to obtain vibration data corresponding to the plurality of rotating components or each of the plurality of rotating components,
- wherein from the step of resampling there is obtained for analysis a vibration signature for a component of interest at predetermined angular increments.
9 more elements
A method of measuring and analyzing vibrations of a mechanical system having a reference shaft and a plurality of rotating components, including the steps of:
- tabulating, in a specification table, gear ratios of the plurality of rotating components relative to the reference shaft in integer form;
- establishing a measurement specification and communicating the measurement specification to a digitizer, the measurement specification including a sample rate at which vibration data is to be recorded and operating conditions of the mechanical system that are to be met before vibration data pertaining to the mechanical system is recorded;
- recording data from the mechanical system during operation, the data comprising rotational speed of the reference shaft received from a first sensor operatively coupled to the reference shaft and vibration data received from one or more vibration sensors operatively coupled to one or more of the reference shaft and the plurality of rotating components;
- and
- resampling the recorded vibration data using the gear ratios defined in the specification table to obtain vibration data corresponding to the plurality of rotating components or each of the plurality of rotating components,
- wherein from the step of resampling there is obtained for analysis a vibration signature for a component of interest at predetermined angular increments;
- and
- isolating vibrations from a rotating component to be analyzed by removing from the recorded vibration data waveform components corresponding to vibrations of mating components, including the steps of:
- obtaining a vibration waveform of the mechanical system and performing a FFT operation on the vibration waveform;
- identifying a rotating mating gear for which harmonics of the vibration waveform of the mating gear are to be removed;
- and
- removing or minimizing the harmonics to a background level.
9 more elements
A method of measuring and analyzing vibrations of a mechanical system having a reference shaft and a plurality of rotating components, including the steps of:
- tabulating, in a specification table, gear ratios of the plurality of rotating components relative to the reference shaft in integer form;
- establishing a measurement specification and communicating the measurement specification to a digitizer, the measurement specification including a sample rate at which vibration data is to be recorded and operating conditions of the mechanical system that are to be met before vibration data pertaining to the mechanical system is recorded;
- recording data from the mechanical system during operation, the data comprising rotational speed of the reference shaft received from a first sensor operatively coupled to the reference shaft and vibration data received from one or more vibration sensors operatively coupled to one or more of the reference shaft and the plurality of rotating components;
- and
- resampling the recorded vibration data using the gear ratios defined in the specification table to obtain vibration data corresponding to the plurality of rotating components or each of the plurality of rotating components,
- wherein from the step of resampling there is obtained for analysis a vibration signature for a component of interest at predetermined angular increments;
- and
- identifying a rotating component fault in a waveform, including:
- trending a FM4 peak to peak value of the waveform;
- and
- triggering an alarm once the FM4 peak to peak trended value exceeds a predetermined level.
8 more elements
A method of measuring and analyzing vibrations of a mechanical system having a reference shaft and a plurality of rotating components, including the steps of:
- tabulating, in a specification table, gear ratios of the plurality of rotating components relative to the reference shaft in integer form;
- establishing a measurement specification and communicating the measurement specification to a digitizer, the measurement specification including a sample rate at which vibration data is to be recorded and operating conditions of the mechanical system that are to be met before vibration data pertaining to the mechanical system is recorded;
- recording data from the mechanical system during operation, the data comprising rotational speed of the reference shaft received from a first sensor operatively coupled to the reference shaft and vibration data received from one or more vibration sensors operatively coupled to one or more of the reference shaft and the plurality of rotating components;
- and
- resampling the recorded vibration data using the gear ratios defined in the specification table to obtain vibration data corresponding to the plurality of rotating components or each of the plurality of rotating components,
- wherein from the step of resampling there is obtained for analysis a vibration signature for a component of interest at predetermined angular increments;
- and
- performing a subroutine of retrieving a force waveform from a vibration response waveform, including the steps of:
- obtaining a system response spectrum;
- identifying gear meshing harmonics from the system response spectrum;
- deleting gear meshing harmonics from the system response spectrum;
- calculating a Cepstrum from the spectrum and applying a lifter to remove components corresponding to system response;
- and
- applying an inverse FFT routine to obtain a waveform of a forcing impulse.
11 more elements
A method of measuring and analyzing vibrations of a mechanical system having a reference shaft and a plurality of rotating components, including the steps of:
- tabulating, in a specification table, gear ratios of the plurality of rotating components relative to the reference shaft in integer form;
- establishing a measurement specification and communicating the measurement specification to a digitizer, the measurement specification including a sample rate at which vibration data is to be recorded and operating conditions of the mechanical system that are to be met before vibration data pertaining to the mechanical system is recorded;
- recording data from the mechanical system during operation, the data comprising rotational speed of the reference shaft received from a first sensor operatively coupled to the reference shaft and vibration data received from one or more vibration sensors operatively coupled to one or more of the reference shaft and the plurality of rotating components;
- identifying and separating synchronous and non-synchronous components from sampled signal values via harmonic analysis;
- determining gearing vibration characteristics based on the identified synchronous component;
- and
- determining bearing vibration characteristics based on the identified non-synchronous component.
4 more elements
A vibration measurement and analysis system for a mechanical system having a reference shaft and a plurality of rotating components including:
- a sensor operatively coupled to the reference shaft for obtaining rotation speed thereof;
- one or more vibration sensors attached to one or more of the reference shaft and the plurality of rotating components for recording vibration measurements of the system, the vibration measurements being represented by one or more signals;
- a data collection device for recording in integer form gear ratios of the plurality of rotating components relative to the reference shaft and for recording the one or more signals with reference to the recorded gear ratios;
- an automated analysis and display device for generating one or more analysis metrics from the signals, the device being configured to obtain vibration information for a shaft of interest based on the vibration measurements with reference to recorded gear ratios,
- wherein the one or more analysis metrics are used to identify a presence of gear or bearing faults within the rotating components of the mechanical system, for which the signals are recorded, by:
- determining gearing vibration characteristics based on a synchronous component of the analysis metrics,
- determining bearing vibration characteristics based on a non-synchronous component of the analysis metrics;
- and
- a transmission medium for transmission of the signals to at least one of a digitizer unit and the automated analysis and display system.
6 more elements
Dependencies are inferred from the claim text.