Wyniki wyszukiwania - BazTech

1

Analysis of the Impact of Selected Factors on Damage to Rolling Bearings of Rail Vehicle Wheelsets

Biel Paweł, Szkoda Maciej, Machno Magdalena

Advances in Science and Technology. Research Journal

|

2024

|

Vol. 18, no 5

206--216

EN

This work attempts to demonstrate the root causes of failure of the bearing of rail vehicle wheel sets. The work presents the recommended methodology for analyzing damage to the bearing of rail vehicle wheel sets. It was important that the end result of the analyzes was to correctly identify the root cause of the bearing failure. The results of the failure analysis of selected bearings showed that the most probable causes of their failure were: irregularities during the maintenance phase (including failure to comply with inspection intervals), lack of sufficient supervision and/or failure to properly secure the bearing pressure cap mounting bolts, intrusion of external contaminants and/or contamination of the lubricant at the stage of installation and maintenance activities, electrical erosion. The above-mentioned possible causes of bearing damage provide important information that allows for better prevention of damage.

2

A Study on the Channel and Gap Flow Simulation For Electrical Discharge Micro-Drilling of Inconel 718 Superalloy

Machno Magdalena, Trajer Marcin, Czeszkiewicz Adrian, Żurawka Paulina

Advances in Science and Technology. Research Journal

|

2024

|

Vol. 18, no 2

159--176

EN

The process of electrical discharge micro-drilling (micro-EDD) of micro holes is used in the aviation, automotive and biomedical industries. In this process, an important issue affecting the stability and efficiency of the process is the flow of the working fluid through the tool electrode channel and the front and side gap areas. Because tool electrodes have diameters below 1 mm. Many factors present in the EDM-drillig process occurring on a micro scale mean that a full explanation of the phenomena affecting the process is limited. The solution is to analyze the phenomena in the process based on the results of numerical simulations, which are based on real measurements. The aim of this work is to analyze the flow of de-ionized water through a brass single-channel electrode with a channel diameter of 0.11 mm and a front and side gap. The liquid flow was analyzed for various variants (with and without cavitation, with added rotation of the tool electrode, with and without surface roughnes with material particles). In simulation, it is important to gradually increase the complexity of the model, starting with the simplest model and gradually adding further phenomena. Analysis of the simulation results showed a significant impact on the liquid flow of cavitation, as well as the presence of vortex gaps in some areas, which have a significant impact on the process of drilling micro holes.

3

Hazard and risk analysis of railway vehicle control systems according to safety integrity levels

Kaczor Grzegorz, Szkoda Maciej, Machno Magdalena

Transport Problems

|

2023

|

T. 18, z. 1

179--192

EN

This article presents an approach to the verification of the safety integrity level (SIL) of rail vehicle subassemblies in accordance with the applicable railway standards PN-EN ISO 50126-1, PN-EN ISO 50126:2, and PN-EN ISO 50129. Particular attention has been given to the calculation procedure related to the determination of the tolerable hazard rate and tolerable functional failure rate indicators in a situation where various reliability indicators have been declared for components of rail vehicles, such as MTTFD or B10D. In this case, the verification of the safety integrity level using the above mentioned railway standards may be difficult, and it becomes necessary to use additional standards for safety systems based on electronic components. An example is the PN-EN ISO 13849-1:2006-01 standard, which contains a calculation method based on the transformation of the exponential model, which is useful for hazard and risk analyses of electronic systems containing components with different reliability indices. Another supplementary standard is the PN-EN 61025:2007 standard, which concerns fault tree analysis. Based on the above-mentioned standards, an algorithm was developed to verify the safety integrity level of the frequency converter control system. The obtained results allowed us to confirm the fulfillment of the functional safety requirements of the considered system.