ISSN 1805-3386

April 6, 2020


2015 No.1

The Impacts of Unbalance on the Start-up Dynamics of Flexibly Mounted Rotors

Jirků, S., Thöndel, E.

The paper deals with the impacts of unbalance on the start-up behaviour of flexibly mounted rotors with viscous damping. It provides an overview of the dimensionless parameters describing the system in question as well as the properties determining the influence of various degrees of static unbalance on the system start-up behaviour for different driving torque scenarios, such as transient-state and steady-state differences as opposed to balanced rotors, vibration-induced power losses, etc.


Keywords: Dynamics, unbalance, simulation, driving torque.


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Analysis of a Partly Sprung Drive

Dub, M., Kolář, J., Lopot, F., Dynybyl, V., Berka, O.

During the operation of trams in cities the bogies and drives are dynamically loaded through acceleration, deceleration, passaging curves and evidently by the roughness of the tram track. These added dynamic loads can significantly increase the wearing of tram drive components. The aim of this analysis is the investigation of stress state and motions of the gearbox hinge (support). For this purpose, strain gauges and optical system Qualisys are used. Special type of the strain gauges arrangement for measuring tension and bend together is designed. Acquired data are processed in the software Matlab and in the user interface of the Qualisys software.


Keywords: Tram drive, tram bogie, induction motor, axle gearbox, gearbox hinge, strain gauges, Qualisys, Matlab.


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Design of a Wheelset Drive

Kolář, J.

The paper describes trends in individual wheelset drive and drives of the independently rotating wheels of modern low-floor trams and railway vehicles. It documents the way of a constructive design of the individual wheelset drive (without gearbox) and wheelset drive with gearboxes.


Keywords: Railway vehicle, modern AC drives, design of mechanical parts of traction drive, low-floor trams, electric locomotive, electric train units.


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Design of Semi-active Magnetorheological Valve with Non-magnetic Bypass

Kubík, M., Mazůrek, I., Roupec, J., Strecker, Z., Macháček, O.

The paper presents a methodology of design of a semi-active magnetorheological (MR) valve. The methodology was composed of the non-Newtonian fluid flow analysis and FEM analysis of a magnetic circuit. Based on the present methodology a MR valve was designed. The MR valve achieves damping force 1600 N at a velocity of 0.15 m/s. The time response was determined to 6 ms.


Keywords: Magnetorheological valve, MR valve, MR fluid.


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Current State of WAMS at ČEPS, a.s.

Havrda, M.

Aim of this document is to introduce the Wide Area Monitoring System used in the transmission grid of Czech Republic, to show some examples of unusual states in the transmission grid detected by the WAMS and to outline the future development in this area.


Keywords: Wide Area Monitoring System (WAMS), Phasor Measurement Unit (PMU), Phasor Data Concentrator (PDC), Supervising Server (SVS).


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The Gear Tooth Flank Temperature Measurements System

Mazač, M., Herajn, P., Svoboda, M.

This paper deals with a design of equipment for the temperature measurements near the gear tooth flank. The paper describes choosing of temperature sensors and a method of data transport from the rotating shaft. The calibration of sensors is described too. Instructions for use are introduced in the text. The equipment for temperature measurements was tested on a little stand which was specially designed. The goal of this paper is the design and testing of equipment for temperature measurements near a gear tooth flank.


Keywords: Measurement, temperature, gear, tooth flank.


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