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To improve the fault identification accuracy of rolling bearings due to the problems of parameter optimization and low convergence accuracy, a novel fault diagnosis method for rolling bearings combining wavelet threshold de-noising, genetic algorithm optimization variational mode decomposition (GA-VMD) and the whale optimization algorithm based on the von Neumann topology optimization least squares support vector machine (VNWOA-LSSVM) is proposed in this manuscript. First, wavelet threshold de-noising is used to preprocess the vibration signal to reduce the noise and improve the signal-to-noise ratio (SNR). Second, a genetic algorithm (GA) is utilized to optimize the parameters of variational mode decomposition (VMD), and optimized VMD is adopted to extract the fault feature information. The VNWOA-LSSVM fault diagnosis model is built to train and identify the fault feature vectors. The proposed method is validated by experimental data. The results show that this method can not only effectively diagnose various damage positions and extents of rolling bearings but also has good identification accuracy.INDEX TERMS Wavelet threshold de-noising, genetic algorithm, variational modal decomposition, von Neumann topology, rolling bearing.

Skid damage affects the performance of aviation bearing, which covers different disciplines in tribology, thermology, materials science, dynamics, et al. In this manuscript, a novel horizontal skid damage test rig of a rolling bearing with higher rotation accuracy and better linear contact was built, which can simulate the rolling/sliding contact between the roller and inner ring. Combining with temperature, load, speed, slip, and surface microscopy, the skid damage mechanism of roller bearings was analyzed from a multi-information perspective. Meanwhile, the dynamic lubrication failure process of the contact pair in rolling bearings with the time-varying slip and temperature distribution was revealed. The effect of different radial loads, inner ring speeds, lubricating oil quantities, and states of cleanliness on the time-varying characteristics of the temperature and the slip of the rolling bearing were obtained. Among them, the radial load has the greatest influence on the slip rate of rolling bearing. In addition, the test results show that the skid damage under extremely light load is the comprehensive effect of adhesive wear and thermal failure.

Purpose The purpose of this study is to reveal the lubrication performance of textured roller bearings under various texture size, texture depth, texture types and slip. Design/methodology/approach In the present study, the improved thermal elastohydrodynamic lubrication method based on the surface texturing of the textured roller bearings is proposed, and then the effect of texture size, texture depth, texture types and slip on the contact pressure, film thickness and temperature distribution are analyzed systematically. Findings The results show that the pressure decreases and the film thickness increases on the contact area because of the surface texturing. The temperature increases first and then decreases as the texture size increases, and then the temperature increases as the texture depth and the slip increases. Compared to circle and square texture, cross texture can obviously decrease the temperature on the contact area. The effectiveness of the proposed method is verified. Originality/value This study can help to reduce friction and wear of textured roller bearings. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2020-0318/

Skidding damage mechanism of rolling bearings is not clear, due to the influence of various coupling factors. To solve this problem, it is important to identify and diagnose skidding damage and study the vibration characteristics in rolling bearings. Based on Fast Fourier Transform (FFT) and Discrete Wavelet Transform (DWT), vibration signals of rolling bearings are extracted and analyzed, and then the skidding damage of rolling bearings from multiple signals perspectives is identified. The relationship between the variation in the radial load, temperature, slip and the skidding damage of rolling bearings under time-varying slip conditions is analyzed comprehensively, and then the influence of different factors on bearing skidding damage is studied. The integrated analysis of the vibration, load, temperature, slip rate and other multivariate signals information shows the starting time of skidding damage. This research can be conducive to reduce vibration and prolong the life of rolling bearings.