Selection of torsional vibration damper based on the results of simulation

So far in engineering practice torsional and transverse vibration damping characteristics of the rotating systems were selected independently. This has resulted from the use of linearized equations of motion in calculations. Linearization results in the loss of information on the coupling between vibration. Currently, increase of the technical requirements to the rotating systems makes it necessary to conduct research in the non-linear range. Because the appropriate analytical methods for determining the form and frequency of vibrations in nonlinear systems are currently under development, simulation methods and analysis solutions in the time domain are growing in importance. In case of task consisting of selection an adequate torsional vibration damper, it is necessary to repeat the simulation calculations for the selected set of parameters, which is very time consuming and is a major drawback of this method. The aim of presented in the work simulation studies was a choice of such a torsional vibration damper, which also would reduce lateral vibration amplitude. The Matlab-Simulink environment and the library of Simulink blocks developed by authors and intended to model rotating systems, in any configuration, was used. Known in the literature the dynamic model of a broadband torsional vibration damper has been implemented in a form of an additional block of the above-recited library

Science and education at the Faculty of Transport (SUT)

The studies in the field of transport began at the Silesian University of Technology in 1969. Originally, they were carried out in Transport and Communication Unit of Mcchanical and Power Engineering Faculty. In 1974 the Institute of Transport and Communication, operating as a faculty, was established. In 1984 the Institute of Transport was organized. In 1992 the University structure was reorganized which resulted in combining the Institute with the Faculty of Materials Science. Metallurgy. Transport and Management that was newly established in Katowice

Application of the finite-element method for determining the stiffness of rolling bearings

The paper presents the results of numerical tests performed with use of the FEM method, the aim of which was determining the stiffness of the outer raceway - rolling element - inner raceway system of bearing 6307. The characterization obtained has been compared with a characterization determined with analytical methods and in the next stage, it will be used to determine the total stiffness of the bearing, variable in working time. Correct modelling of bearing stiffness is one of important conditions for obtaining correct results of simulation calculations. Obtained results will allow the determination of possibilities of limiting vibroactivity of toothed gears, commonly used in transport

Application of the vibration test in the evaluation of the technical condition of shock absorbers built into the vehicle

The paper presents an assessment of the technical condition of the vehicle shock absorbers built into the vehicle on the basis of the signals recorded during the vibration test. The test was performed on a test stand with kinematic harmonic forcing. The test stand can enforce vibrations in the range of 0-21 Hz and amplitude of 6 mm. The shock absorbers with indicated technical condition were built into the vehicle (the new shock absorber and the one with oil leak). The research was conducted on the twin-tube hydraulic shock with a modified structure that allows to change the amount of the fluid. The study was conducted for the front suspension shock absorber of passenger car with an independent McPherson front suspension. Acceleration was measured using capacitive sensors of accelerations type ADXL. Acceleration was recorded on test stand platform and near the axis of the wheel and on the upper point of attachment of the McPherson strut. Registered acceleration diagrams were subject to further treatment consisting of filtration and analysis. The results were compared for selected technical states

Stabilizer bars: Part 3. Production methods

The article outlines the methods of stabilizer bar production as well as selected issues concerning the theory of cold roll forming. A proper construction and the selection of parameters are fundamental factors influencing the selection of a suitable production process. The selection of the manufacturing process has a fundamental impact on the quality and durability of the stabilizer bars

Emissions from a medium-duty crdi engine fuelled with diesel : biodiesel blends

In the present work, biofuels produced from different raw fatty materials have been proposed as a dominant fuel component in biodiesel–diesel fuel blends. Biofuels were produced from pork lard and rapeseed oil by alkali transesterification using methyl alcohol. Blends of biofuels in volumetric proportions of 60 and 80% of the biocomponent and the remaining part of the conventional fuel were used in a compression ignition engine designed for medium-duty vehicles. The experiments were conducted at two engine rotational speeds (1500 and 3000 rpm, respectively) and a set of load conditions (50, 100, and 200 Nm, respectively). The tests focused on engine efficiency parameters (brake-specific fuel consumption and brake fuel conversion efficiency) as well as exhaust gas emissions (hydrocarbons, carbon monoxide, and carbon dioxide were determined). The obtained results indicate that blends containing biocomponents produced from pork lard were characterized by superior fuel consumption and efficiency results, compared to blends containing biocomponents produced from rapeseed oil. In terms of exhaust emissions, biocomponents produced from pork lard were also characterized by lower emission of all of the examined components compared to rapeseed methyl ester–diesel blends. This study proposes that fuel components obtained from custom (animal) raw-fatty material can be an effective substitute for commonly used rapeseed oil methyl esters.© The Authors. Published by Exeley Inc. with Creative Commons licence (CC BY 4.0).fi=vertaisarvioitu|en=peerReviewed

URBAN PUBLIC TRANSPORT WITH THE USE OF ELECTRIC BUSES – DEVELOPMENT TENDENCIES

Summary. The programing documents of the European Union determine the direction of transport systems development, including large cities and agglomerations. The context of these actions which aim to transform into ecologically clean and sustainable transport system is a significant reduction of greenhouse gas emissions. Assuming that public transport will significantly reduce the use of combustion-powered buses, studies on urban logistic enabling the use of electric buses for public transport are needed. The article presents the variants and scenarios for electric buses implementation in urban public transport, as well as the decision algorithm to support electric bus implementation based on technological, organisational, economic and ecological variables

Influence of construction factors on the vibrational activity of the gearing

The paper presents the results of numerical and experimental studies on the influence of selected factors on the dynamic effects and vibroactivity of the gearing. The studies were performed using a custom developed dynamic model of a test stand with the gears operating in the circulating power system