Condition monitoring indicators for pitting detection in planetary gear units

Abstract

In industrial field, there is an increasing demand for monitoring systems enabling predictive maintenance programs. In this context, the present work concerns the monitoring of distributed wear (pitting) in planetary gearboxes. For this purpose, some metrics of the synchronous average of the vibration signal, based on the statistical moment of the fourth order, are present in literature; in this paper, a new indicator is proposed, namely NA4mod. The effectiveness of this metric in identifying the early stage of pitting has been evaluated by conducting an accelerated life test of about 700 hours on a test bench using a back-to-back configuration. The paper introduces the proposed metric, describes the test, presents and dis-cusses the results. Metric NA4mod exhibits satisfactory capability to detect pitting with better reliability than other metrics in literature. In addition, the metric is shown to be sensitive to both early stage damage and pitting severity in the final stage. Results are verified by means of wavelet-transform analysis.

Research of modified gear drive for multioperational machine with increased load capacity

“…In case of continuous operation, it is necessary to monitor the vibrations of the gear drive. In this regard, a promising method is the control of distributed wear (pitting corrosion) in planetary gears, proposed in [29].…”

A geometrical surface texture study of sliding sleeves and pins after bench tests

“…Their very high sensitivity to wear was the reason for undertaking further research on reducing the wear effect. The article [20] considered planetary gear vibration response to detect gear pitting due to wear. The research objects assumed in this article are all external and internal pins and the sleeves installed on them.…”

Diagnostics and prognostics of planetary gearbox using CWT, auto regression (AR) and K-means algorithm

“…The unexpected failures of planetary gearboxes will lead to increased downtime and structural damage. The condition monitoring of planetary gearboxes has received intensive research in the past decade due to its demand in heavy industrial applications [1] [2]. It is very important to diagnose the early degradation of gears and bearings to prevent catastrophic accidents and production loss.…”

“…Therefore, gear tooth defects are one of the main causes of planetary gearbox failure. In the last 30 years, methods for detecting the early stages of faults in gears as well as bearings have been established by various researchers [2].…”