Abstract: Embodiments are directed to a drive shaft apparatus comprising a first rotary member and a second rotary member arranged coaxially with said first rotary member. The rotary members are fixedly connected at a first end so that they rotate together. Each rotary member has a set of elements spaced apart around its circumference at a second end. The elements on the first rotary member are spaced apart from the elements on the second rotary member at rest. The first rotary member undergoes torsion when a load is applied during rotation, which causes the first rotary member elements to move closer to the second rotary member elements. The first elements engage the second elements when a torque load less than a yield torque is applied to the first rotary member, which transfers at least a portion of the torque load to the second rotary member.

Abstract: Embodiments are directed to a drive shaft apparatus comprising a first rotary member and a second rotary member arranged coaxially with said first rotary member. The rotary members are fixedly connected at a first end so that they rotate together. Each rotary member has a set of elements spaced apart around its circumference at a second end. The elements on the first rotary member are spaced apart from the elements on the second rotary member at rest. The first rotary member undergoes torsion when a load is applied during rotation, which causes the first rotary member elements to move closer to the second rotary member elements. The first elements engage the second elements when a torque load less than a yield torque is applied to the first rotary member, which transfers at least a portion of the torque load to the second rotary member.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining original data based on samples of a vibration signal; converting the original data to an analytical signal having a real component and an imaginary component; determining complex magnitudes of the analytical signal; processing the complex magnitudes of the analytical signal to produce a frequency-domain signal; and determining complex magnitudes of the frequency-domain signal to generate a shock spectrum.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including: obtaining original data based on samples of a tachometer signal; processing the original data to obtain rotational information; processing the original data to produce a sine spectrum; determining complex magnitudes of the sine spectrum; removing dominate torsional mode residuals from the complex magnitudes of the sine spectrum to produce a frequency spectrum; and determining a condition indicator from the frequency spectrum.

Abstract: There is a method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining original data based on samples of a vibration signal and a tachometer signal; generating a time synchronous average vibration signal; processing the time synchronous average vibration signal to produce a frequency-domain spectrum; determining the complex magnitudes of the frequency-domain spectrum; selecting a sub-synchronous band of the complex magnitudes of the frequency-domain spectrum to generate a sub-synchronous spectrum; and determining the mean of the sub-synchronous spectrum to generate a condition indicator.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining rotational information associated with the component; receiving original data indicating the toothmesh frequency of the drive train; filtering the original data to remove energy above the toothmesh frequency; interpolating the filtered original data to generate an integer number of samples per tooth passage; and generating an amplified differential coherence (ADC). In some embodiments, an amplified differential coherence gearbox arrangement value (ADCT) is generated.

Abstract: A method and apparatus for determining failure diagnosis of drive systems of rotorcrafts through measuring the spectral characteristics of rotational oscillations and torsional oscillations and steady windup of a drive shaft. Mechanical anomalies of the drive system will alter the spectral characteristics of rotational oscillations and torsional oscillations and steady windup as detected by a pair of variable reluctance sensors in conjunction with a radial grating mounted on the drive shaft.

Abstract: There is a method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining original data based on samples of a vibration signal and a tachometer signal; generating a time synchronous average vibration signal; processing the time synchronous average vibration signal to produce a frequency-domain spectrum; determining the complex magnitudes of the frequency-domain spectrum; selecting a sub-synchronous band of the complex magnitudes of the frequency-domain spectrum to generate a sub-synchronous spectrum; and determining the mean of the sub-synchronous spectrum to generate a condition indicator.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including: obtaining original data based on samples of a tachometer signal; processing the original data to obtain rotational information; processing the original data to produce a sine spectrum; determining complex magnitudes of the sine spectrum; removing dominate torsional mode residuals from the complex magnitudes of the sine spectrum to produce a frequency spectrum; and determining a condition indicator from the frequency spectrum.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining original data based on samples of a vibration signal; converting the original data to an analytical signal having a real component and an imaginary component; determining complex magnitudes of the analytical signal; processing the complex magnitudes of the analytical signal to produce a frequency-domain signal; and determining complex magnitudes of the frequency-domain signal to generate a shock spectrum.

Abstract: A method, system, and device for diagnosing an anomaly of a monitored component in a drive train, the method including obtaining rotational information associated with the component; receiving original data indicating the toothmesh frequency of the drive train; filtering the original data to remove energy above the toothmesh frequency; interpolating the filtered original data to generate an integer number of samples per tooth passage; and generating an amplified differential coherence (ADC). In some embodiments, an amplified differential coherence gearbox arrangement value (ADCT) is generated.

Abstract: A method and apparatus for determining failure diagnosis of drive systems of rotorcrafts through measuring the spectral characteristics of rotational oscillations and torsional oscillations and steady windup of a drive shaft. Mechanical anomalies of the drive system will alter the spectral characteristics of rotational oscillations and torsional oscillations and steady windup as detected by a pair of variable reluctance sensors in conjunction with a radial grating mounted on the drive shaft.