Slewing bearing

About: Slewing bearing is a(n) research topic. Over the lifetime, 1498 publication(s) have been published within this topic receiving 5309 citation(s).

A Review of Feature Extraction Methods in Vibration-Based Condition Monitoring and Its Application for Degradation Trend Estimation of Low-Speed Slew Bearing

Abstract: This paper presents an empirical study of feature extraction methods for the application of low-speed slew bearing condition monitoring. The aim of the study is to find the proper features that represent the degradation condition of slew bearing rotating at very low speed (≈ 1 r/min) with naturally defect. The literature study of existing research, related to feature extraction methods or algorithms in a wide range of applications such as vibration analysis, time series analysis and bio-medical signal processing, is discussed. Some features are applied in vibration slew bearing data acquired from laboratory tests. The selected features such as impulse factor, margin factor, approximate entropy and largest Lyapunov exponent (LLE) show obvious changes in bearing condition from normal condition to final failure.

EEMD-based multiscale ICA method for slewing bearing fault detection and diagnosis

Abstract: A novel multivariate and multiscale statistical process monitoring method is proposed with the aim of detecting incipient failures in large slewing bearings, where subjective influence plays a minor role. The proposed method integrates the strengths of the Independent Component Analysis (ICA) multivariate monitoring approach with the benefits of Ensemble Empirical Mode Decomposition (EEMD), which adaptively decomposes signals into different time scales and can thus cope with multiscale system dynamics. The method, which was named EEMD-based multiscale ICA (EEMD-MSICA), not only enables bearing fault detection but also offers a mechanism of multivariate signal denoising and, in combination with the Envelope Analysis (EA), a diagnostic tool. The multiscale nature of the proposed approach makes the method convenient to cope with data which emanate from bearings in complex real-world rotating machinery and frequently represent the cumulative effect of many underlying phenomena occupying different regions in the time–frequency plane. The efficiency of the proposed method was tested on simulated as well as real vibration and Acoustic Emission (AE) signals obtained through conducting an accelerated run-to-failure lifetime experiment on a purpose-built laboratory slewing bearing test stand. The ability to detect and locate the early-stage rolling–sliding contact fatigue failure of the bearing indicates that AE and vibration signals carry sufficient information on the bearing condition and that the developed EEMD-MSICA method is able to effectively extract it, thereby representing a reliable bearing fault detection and diagnosis strategy.

Modelling of rollers in calculation of slewing bearing with the use of finite elements

Abstract: During the operation the slewing bearings are a subject to a large deformation. It is the cause of unequal load of the rolling elements. Deformation of the bearing can be calculated by the FE models, in which the rolling elements are replaced by the truss elements. These elements ought to have a right load–deformation characteristic. In the paper the method of calculating such a characteristics for the roller slewing bearings is presented. The type and the parameters of the roller generator correction have the largest influence on the analysed characteristics, considerably smaller is an effect of the plastic deformations in the contact zone of the roller and the bearing raceway.

Load distribution in a four contact-point slewing bearing

Abstract: This article discusses a calculation procedure for determining the load distributions in the rolling elements of a four contact-point slewing bearing with one row of ball bearings, under general load conditions (moment, axial load and radial load). What is discussed here is an extension to four contact-point of the general bearing theory, which calculates the load distributions in two contact-point rolling elements. Laburpena Artikulu hau kalkulu-prozedura bat da eta bide ematen du karga orokorreko (momentu, karga axial eta karga erradial) baldintzapean dagoen errenkada bakarreko boladun orientazio-koroa bateko errodadura-elementuetan indar-banaketa kalkulatzeko. Prozedurak errodamenduen teoria orokorra lau ikutze-puntura luzatzen du. Teoria orokor horrek Hertz-en teoria du oinarri eta bi ukitze-puntuko kasuan, errodadura-elementuetan indar-banaketa kalkulatzeko balio du.

3D Simplified Finite Elements Analysis of Load and Contact Angle in a Slewing Ball Bearing

Abstract: Bolted bearing connections are one of the most important connections in some industrial structures, and manufacturers are always looking for a quick calculation model for a safe design. In this context, all the analytical and numerical models reduce the global study to the study of the most critical sector. Therefore, the main inputs for these models are the maximal equivalent contact load and the corresponding contact angle. Thus, a load distribution calculation model that takes all the important parameters, such as the stiffness of the supporting structure and the variation in the contact angle, into consideration is needed. This paper presents a 3D finite element (FE) simplified analysis of load distribution and contact angle variation in a slewing ball bearing. The key element of this methodology, which is based on the Hertz theory, is modeling the rolling elements under compression by nonlinear traction springs between the centers of curvature of the raceways. The contact zones are modeled by rigid shells to avoid numerical singularities. Each raceway curvature center is coupled to the corresponding contact zone by rigid shells. The main contribution of this method is not only the evaluation of the contact loads with a relatively reduced calculation time but also the variation in the contact angle from the deformed coordinates of the curvature centers. Results are presented for several loading cases: axial loading, turnover moment, and a combined loading of axial force and turnover moment. The influence of the most important parameters such as the contact angle, the stiffness of the bearings, and the supporting structure is discussed. Finally, a preliminary experimental validation is conducted on a standard ball bearing. The results presented in this paper seem encouraging. The FE study shows an important influence of several parameters and a good correlation with experimental results. Consequently, this model can be extended to other types of slewing bearings such as roller bearings. Moreover, it can be implemented in complex industrial structures such as cranes and lifting devices to determine the corresponding load distributions and contact angles and, consequently, the most critical sector.