Jaroslaw Sep

Experimental testing of journal bearings with two-component surface layer in the presence of an oil abrasive contaminant

The aim of the paper is to present a new design of the two-component surface layer journal and the experimental results indicating usefulness of the new design. The novelty of the design consists of placing soft material stripes on the bearing journal surface and forming microgrooves in the material contact zone. Experiments indicate clearly on the usefulness of the design, especially in the case when oil is contaminated by hard particles. In every stage of testing, the sensitivity to contamination of the bearing with the two-component surface layer journal is about one-fifth that of the case of the conventional bearing.

CNC Milling Tool Head Imbalance Prediction Using Computational Intelligence Methods

In this paper, a mechanical imbalance prediction problem for a milling tool heads used in Computer Numerical Control (CNC) machines was studied. Four classes of the head imbalance were examined. The data set included 27334 records with 14 features in the time and frequency domains. The feature selection procedure was applied in order to extract the most significant attributes. Only 3 out of 14 attributes were selected and utilized for the representation of each signal. Seven computational intelligence methods were applied in the prediction task: K–Means clustering algorithm, probabilistic neural network, single decision tree, boosted decision trees, multilayer perceptron, radial basis function neural network and support vector machine. The accuracy, sensitivity and specificity were computed in order to asses the performance of the algorithms.

The Analysis of Abrasive Wear of the Helical Grooved Journal Bearing

The paper presents results of the tests concerning slide bearings having modified journal with helical groove. Such a bearing is more wear-resistant than the classical bearing in case of hard particles presence in oil. Investigations show that above mentioned modification results in over twofold decrease in wear intensity in case of suitable helical groove parameters. Differences in worn journals surface topography for investigated variants have also been stated.

Selected Properties of Bearings with Helical Groove on the Journal

The paper presents results of tests concerning slide bearing with helical groove on the journal selected properties. It has been stated that during lubrication with contaminated oil helical groove results in wear decrease. On the other hand while lubricating agent was clean oil helical groove results in load carrying capacity decrease and oil flow rate increase. The proposition of non-dimensional index describing the groove and helical line is also presented in the paper. This index is correlated with bearing characteristics and its wear