Embodiments of a process for estimating a rotational speed of a rotating component and a process for estimating an acceptable rotor imbalance of a rotating component are provided herein. The process for estimating the rotational speed of a rotating component for a charging system comprises measuring a vibration signal of the rotating component by means of a sensor; and identifying harmonic train members from a plurality of peaked components of the vibration signal. Further, the process comprises determining a candidate fundamental frequency from the harmonic train members; and determining a derived vibration amplitude value from the vibration signal. This determination involves a filtering of the vibration signal, removing periodic contributions having a high amplitude. A scalar value is then derived from the filtered signal as a derived vibration amplitude value, representing the integrated total vibration amplitude of the filtered signal at the current speed. The process comprises verifying a consistency condition between the derived vibration amplitude value and the candidate fundamental frequency using a predetermined speed-amplitude map, associating speed values with their respective derived vibration amplitude values. For determining an acceptable rotor imbalance, a speed-amplitude map obtained at a time when the imbalance is acceptable is compared to a speed-amplitude map at a later point in time. An offset between the maps may indicate an inacceptable imbalance.

Embodiments of a process for estimating a rotational speed of a rotating component and a process for estimating an acceptable rotor imbalance of a rotating component are provided herein. The process for estimating the rotational speed of a rotating component for a charging system comprises measuring a vibration signal of the rotating component by means of a sensor; and identifying harmonic train members from a plurality of peaked components of the vibration signal. Further, the process comprises determining a candidate fundamental frequency from the harmonic train members; and determining a derived vibration amplitude value from the vibration signal. This determination involves a filtering of the vibration signal, removing periodic contributions having a high amplitude. A scalar value is then derived from the filtered signal as a derived vibration amplitude value, representing the integrated total vibration amplitude of the filtered signal at the current speed. The process comprises verifying a consistency condition between the derived vibration amplitude value and the candidate fundamental frequency using a predetermined speed-amplitude map, associating speed values with their respective derived vibration amplitude values. For determining an acceptable rotor imbalance, a speed-amplitude map obtained at a time when the imbalance is acceptable is compared to a speed-amplitude map at a later point in time. An offset between the maps may indicate an inacceptable imbalance.

A fan inspection jig includes a jig assembly having multiple spring abutment pillars for holding two sides of a fan (or a series fan) to make the fan or the series fan positioned in a suspending position. A vibration sensor is disposed in at least one of the spring abutment pillars of two sides of the fan for measuring a vibration signal of the fan in operation.

A fan inspection jig includes a jig assembly having multiple spring abutment pillars for holding two sides of a fan (or a series fan) to make the fan or the series fan positioned in a suspending position. A vibration sensor is disposed in at least one of the spring abutment pillars of two sides of the fan for measuring a vibration signal of the fan in operation.

Sensor modules mountable on a wheel are described. A sensor module mountable adjacent to a rim of a wheel includes a first set of one or more piezoelectric sensors; and a first elastic support with the first set of one or more piezoelectric sensors coupled thereon so that the first set of one or more piezoelectric sensors are spaced apart from the rim of the wheel. A wheel that includes a rim and the sensor module is also disclosed. A method includes receiving a force on a tire mounted on a rim of a wheel. The tire is in contact with an elastic support with one or more piezoelectric sensors coupled thereon so that the force causes strain in the elastic support and the one or more piezoelectrical sensors. The method also includes, in response to receiving the force, generating electrical signals from the one or more piezoelectric sensors.

An apparatus is described that determines an estimated rotational speed of a rotating component of a machine in the absence of a reliable tachometer signal to indicate an actual rotational speed. The apparatus includes a processor that determines a range of rotational speeds for the machine based on historical data, generates a vibration spectrum based on measured digital vibration data, identifies vibration peaks in the spectrum, determines a maximum peak amplitude of the vibration peaks, determines candidate frequency values within the range of rotational speeds, for multiple harmonics identifies a nearest peak within a spectral peak frequency tolerance of each harmonic, determines an error value based on a difference between the candidate frequency value and the nearest peak frequency value, determines an error sum value for each candidate frequency value, which is an iterative sum of the error values determined for the harmonics, determines the estimated rotational speed of the machine based on the candidate frequency value having a largest error sum value, and analyzes the digital vibration data using the estimated rotational speed of the machine to determine an operational characteristic of the machine.

An apparatus is described that determines an estimated rotational speed of a rotating component of a machine in the absence of a reliable tachometer signal to indicate an actual rotational speed. The apparatus includes a processor that determines a range of rotational speeds for the machine based on historical data, generates a vibration spectrum based on measured digital vibration data, identifies vibration peaks in the spectrum, determines a maximum peak amplitude of the vibration peaks, determines candidate frequency values within the range of rotational speeds, for multiple harmonics identifies a nearest peak within a spectral peak frequency tolerance of each harmonic, determines an error value based on a difference between the candidate frequency value and the nearest peak frequency value, determines an error sum value for each candidate frequency value, which is an iterative sum of the error values determined for the harmonics, determines the estimated rotational speed of the machine based on the candidate frequency value having a largest error sum value, and analyzes the digital vibration data using the estimated rotational speed of the machine to determine an operational characteristic of the machine.

The diagnostic system for diagnosing a rotor imbalance of a wind turbine based on acceleration data measured on a nacelle of a wind turbine which is supported by a tower includes a measuring device provided with a triaxial vibration sensor suitable for measuring acceleration data corresponding to vibrations occurring on the nacelle. The system also includes a processing system for processing the acceleration data, suitable for determining the rotor imbalance according to the acceleration data measured on at least two axes on the nacelle. The invention also relates to a method for diagnosing the rotor imbalance of a wind turbine.

The diagnostic system for diagnosing a rotor imbalance of a wind turbine based on acceleration data measured on a nacelle of a wind turbine which is supported by a tower includes a measuring device provided with a triaxial vibration sensor suitable for measuring acceleration data corresponding to vibrations occurring on the nacelle. The system also includes a processing system for processing the acceleration data, suitable for determining the rotor imbalance according to the acceleration data measured on at least two axes on the nacelle. The invention also relates to a method for diagnosing the rotor imbalance of a wind turbine.

Provided is a method to acquire the unbalance of a rotor and a balancing machine, in which, the method to acquire the unbalance of a rotor includes the following procedures: install angle sensor at first position on balancing machine, measure the unbalance of rotor, first unbalance in measuring plane 1 and first unbalance in measuring plane 2 can be measured. Move angle sensor on balancing machine from first position to second position, measure the unbalance of the rotor again, second unbalance in measuring plane 1 and second unbalance in measuring plane 2 can be measured. In the above mentioned two measurements, the unbalance amount of rotor has no change, but the unbalance angle relative to angle reference point on rotor is changed by an angle which equals the angle of the sensor being moved.