Fault feature extraction of gearbox by using overcomplete rational dilation discrete wavelet transform on signals measured from vibration sensors

Asynchronous input gear damage diagnosis using time averaging and wavelet filtering

This paper presents a novel means for suppressing gear mesh-related vibrations. The key components in this approach are piezoelectric actuators and a high-frequency, analog feed-forward controller. Test results are presented and show up to a 70-percent reduction in gear mesh acceleration and vibration control up to 4500 Hz. The principle of the approach is explained by an analysis of a harmonically excited, general linear vibratory system.

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Feedforward Control of Gear Mesh Vibration Using Piezoelectric Actuators

Vibration analysis is the most common means of gear monitoring and diagnostics. Gear vibration is affected by faults but the signal is usually picked up at the case, where it is also affected by the structural response. An appropriate filtering function is therefore proposed to recover the torsional gear vibration from the case vibration signal. The restored gear vibration can then be used with greater confidence than case vibration both for particular diagnostics purposes like crack detection and for more general objectives. This technique and its possible advantages in fatigue crack detection are illustrated in the paper.

Monitoring fatigue cracks in gears

Estimation of the vibration of in-service gears by monitoring the exterior vibration.

The authors used Mindlin's equation, and calculated the natural mode of a circular plate with a solid shaft under the boundary condition of a fixed inner diameter. As the result, the calculated natural frequency of the low mode of the thick circular plate differed greatly from the one measured by modal analysis. The causes were analyzed on the (1, 0) mode of vibration, which had the biggest error, of 78 percent

The Natural Mode of Vibration of a Circular Plate with a Solid Shaft : Correction of Natural Frequency under Consideration of Elastic Deformation on the Boundary between a Circular Plate and a Solid Shaft, and Bending Deformation of the Shaft

Hiroki Maki

Papers

Estimation of the vibration of in-service gears by monitoring the exterior vibration.

The Natural Mode of Vibration of a Circular Plate with a Solid Shaft : Correction of Natural Frequency under Consideration of Elastic Deformation on the Boundary between a Circular Plate and a Solid Shaft, and Bending Deformation of the Shaft