Jacek Feliks

Power consumption tests during start-up of a rectilinear vibration screen

Abstract: This article presents the results of tests performed during the start-up of a vibrating screen, depending on the set start-up time. The tests were conducted using a suspended vibrating screen with a segmental vibration trajectory – in which the vibrations were driven by two vibrating motors mounted directly to the screen’s sieve. The vibrating motors were powered by three-phase voltage and connected to the mains through a frequency converter system, enabling control of the drive current in steady states and during start-up. The instantaneous power drawn by the screen drive was also recorded, and the maximum current flowing in the power supply system was determined for nine assumed start-up times (from 0 s to 8 s). These tests allowed the determination of the most favorable start-up parameters, reducing the drive’s power demand without significantly affecting the kinematic parameters of the screen during start-up.

Keywords: vibrating screen, vibrating motor, screen power demand

Piotr Kipczak

Laser-optical analysis of hydraulic oil degradation in a Doosan 380 LC-5 Excavator

Abstract. This paper presents an analysis of the condition and quality of hydraulic oil used in
a Doosan 380 LC-5 crawler excavator operated under real working conditions. The objective of the study was to investigate qualitative changes in Orlen Hydrol L-HV 46 hydraulic oil as a function of operating hours and to assess the applicability of oil cleanliness analysis as a diagnostic tool for hydraulic systems. Five oil samples were analyzed, including one fresh oil sample. The tests were conducted using a mobile OPCom Portable Oil Lab analyzer manufactured by ARGO-HYTOS, enabling laser-optical oil cleanliness measurements in accordance with PN-EN ISO 4406:2021. The results confirm the progressive degradation of the hydraulic oil with increasing operating time and highlight the importance of systematic oil cleanliness monitoring.

Keywords: hydraulic oil, hydraulic oil cleanliness, tribological diagnostics

Wojciech Korski , Wojciech Horak , Łukasz Bołoz , Roman Niestrój , Artur Kozłowski

BEV in-wheel drive LHD loader

Abstract. The paper presents the construction and the applied design solutions of a prototype, light LHD loader with an innovative in-wheel drive propulsion system. The subject machine is a BEV vehicle with a exchangeable energy storage. It is designed to work in underground mines with no explosion hazard, especially in metal ore mines. The developed structure includes four independent electric drive systems, integrated in the drive nodes, located in the construction of the road wheels. The paper presents the results of simulations used to estimate the required propulsion power and the demand for electric energy in various work regimes and operating conditions. The results of the calculations were used to determine the parameters of the electric drive system components as well as the battery energy/capacity. Additionally, the required parameters of the liquid cooling system for the in-node motors and motor inverters were estimated.

Keywords: self-propelled mining machines, LHD loaders, electric propulsion, battery power,
supply, BEV