Papers by Author: Vladas Vekteris

Abstract: This work investigates agglomeration process of aerosol particles in presence of acoustic field. It is shown that besides orthokinetic and hydrodynamic interaction mechanisms, tribological interaction occurs in presence of acoustic field. This interaction depends on dynamic viscosity of the gas mixture above the liquid surface. The influence of acoustic field on tribological interaction between the aerosol particles was investigated both numerically and experimentally. The obtained results show the positive influence of acoustic field on agglomeration of aerosol particles.

Abstract: The essence of the considered problem is to improve line scale gauge calibration quality by studying vibrations that are induced during the calibration process. To assess the influence of vibrations it is necessary to solve a lot of scientific and technical tasks. Serious difficulties were confronted during the mathematical analysis - development of analytical model and determination of its coefficients. An in-depth analysis of line scale measurement means had to be performed to this aim, because only experimental measurements enabled to estimate the majority of coefficients.

Abstract: Dependence of a comparator reading dynamic error on vibro activity of a carriage is analyzed in the paper. There is shown how change reading errors at action only carriage drive vibrations and at artificially provoked carriage vibrations at different frequencies. Results achieved enable to evaluate the influence of vibration components on reading errors.

Abstract: Results of tribological research of mineral motor oil with and without twisted nematic liquid crystal additive (stearic acid cholesteryl ester) are presented in the article. Experimental research was performed by means of a “fixed segment – rotating roller” tribometer according to the central three-factor second-order rotatable factorial design. The following parameters were accepted as controllable factors: contact pressure (3.32–6.68 MPa), concentration of liquid crystal in lubricant (0.16–1.84 ) and the average height of surface roughness of contacting surfaces of roller and segment (2.5–37.5 μm). The friction coefficient and friction zone temperature were served as output parameters. Regression equations describing the friction process were obtained and tribological efficiency of liquid crystal additive was established.

Abstract: This paper describes experimental investigation of lubricant properties used in locomotive engines. The workbench for experimental investigation is described, and experiment technique is presented. Results and their interpretation show direction for further investigation. Conclusions of results are made.

Abstract: The hydrodynamic tilting-pad journal bearing with a mobile elastic element and choose of its geometry by calculating deformations are analyzed in the paper. It is shown here, that such bearings with elastic elements can use the kinetic energy of the oil, which appears in the incensement volume. When rotor oscillations appear elastic elements disturb the equilibrium of segments and diminish the influence of oscillation. Differential equations are derived for this aim and they allow choosing geometrical parameters of elastic elements independence on the load intensity and the oil temperature.

Abstract: The problem of quality diagnostics of systems with hydrodynamic bearings is analyzed in the paper. In analyzing the problem, the analytical research of the change of friction coefficient, pressure, rotor rotation axis eccentricity in dependence on the wear magnitude between the rotor and the bearing are performed. The method of the analytical research is presented. Results of the analytical research and experimental measurements are depicted in graphs.

Abstract: An analysis of the influence of the change of temperature of a rotor’s system with bearings of sliding friction to the work of a searching system is presented in this paper. Experimental research to gauge the clearance of change between a rotor and bearing subject to change of temperature and frequency of rotor’s rotating is also presented. A special rig and special implements of measurement for doing measurements is included. Experimental measurements done according to the specially made up methodology is in this paper. Also, the article describes and gives the principal system of measurement and analysis methodology to do the experiment and an analysis was done of results and the gauge of consistent pattern of changes of the searched parameters.

Abstract: This article presents a Mechatronic Hydrodynamic Bearings Testing System and describes its main functions. The System’s structure, control and principles of data input/output are given here. The System enables one to evaluate the quality of bearings by spectral analysis of oscillations and orbits of the rotor pivot. Potentials of the System and realization of diagnostic measurements by means of this System are described.

Abstract: The paper’s work examines opportunities of diagnostics of vibroinsulated mechanisms based on the measurement of mechanical vibration. Vibration insulation systems distort the diagnostic signal therefore direct diagnostics of vibration of vibroinsulated mechanisms is impossible. The work’s objective is to analyse the influence of vibration insulation systems on the diagnostics of such mechanisms and to identify the kinds of parameters on which this influence depends. A stand for tests is made for the achievement of this objective; by using the stand the vibration of a mechanism can be simultaneously measured both directly and via the vibration insulation system.