Aspects relating to the reliability calculation of the cutting-teeth mounted on the bucket wheel excavators used in lignite mining

Ovidiu-Bogdan Tomuş,Andrei Andraş,Stela Dinescu,Dumitru Jula,I Bondrea,M Inţă,N.F Cofaru

doi:10.1051/matecconf/201929001020

Abstract

The paper deals with the calculation of the operational reliability for the cutting-teeth mounted on bucket wheel excavators used in lignite extraction in the Oltenia Basin. Based on the data recorded for three types of cutting-teeth used in production, a reliability study has been carried out which determines the main reliability indicators of the quality level of these cutting-teeth. The study compares the constructive and functional characteristics of the three types of cutting-teeth, which is the basic criterion for purchasing a certain type of cutting-tooth, as well as for the supply of spare parts.

Highlights

Four types of bucket wheel excavators (BWE), EsRc-470-15 / 3,5-400, SRS-1300-26 / 3,5500, SRS-2000-30 / 7-2 × 500, and EsRc-1400-30 / 7-630, are used in lignite open pit mines in the Oltenia Coal Basin [1].a chisel type tooth is presented, and the representative geometric parameters defining the shape of the tooth are specified
The teeth that equip the BWE bucket are designed to displace the material from the face and guide it towards the inside of the bucket
Since the working conditions of the teeth are very different, it is necessary to use statistical calculations of their actual operating time. This is done by performing a reliability study that best shows the behavior of the teeth

Summary

Introduction

Four types of bucket wheel excavators (BWE), EsRc-470-15 / 3,5-400, SRS-1300-26 / 3,5500, SRS-2000-30 / 7-2 × 500, and EsRc-1400-30 / 7-630, are used in lignite open pit mines in the Oltenia Coal Basin [1]. Since the working conditions of the teeth are very different, it is necessary to use statistical calculations of their actual operating time This is done by performing a reliability study that best shows the behavior of the teeth. The field studies for the 1400-MII type cutting teeth were performed on EsRc-1400 excavators in the Berbești and Roşia open pit mines on a sample of 70 teeth. It can be stated with certainty that any of the validated distributions can characterize the functionality of the bucket wheel cutting teeth. It is noted the validation of the normal distribution. This distribution law is a particular form of the Weibull distribution law and is characterized by the linear variation of the failure intensity [6]

Theoretical distribution

Findings

Conclusion