scholarly journals SYNCHRONOUS MOTOR WITH INCREASED ROTOR SPEED

2020 ◽  
pp. 125-131
Author(s):  
Aleksei A. Petrov ◽  
Aleksei V. Makarov ◽  
Valeriy G. Makarov ◽  
Nikita Yu. Grigoriev
Keyword(s):  
Electric Motor ◽  
Rotational Speed ◽  
Analytical Calculation ◽  
Structural Features ◽  
Output Shaft ◽  
Stator Windings ◽  
Axis Of Rotation ◽  
Voltage Wave ◽  
Rotor Axis

Development of the design of a synchronous electric motor with six C-shaped stator teeth, the rotor axis of rotation of which is displaced relative to the axis of rotation of the output shaft. The rotational speed of the output shaft is equal to twice the rotational speed of the stator magnetic flux. Determination of the phase shifts of the supply voltages in time and the spatial position of the stator windings. Visualization of the principle of operation of the electric motor under consideration, namely, step-by-step observation of the position of the rotor in space, when the sinusoidal voltage wave changes by an angle equal to π, with a step of π/6. Mathematical description of the engine under consideration, with all the structural features of the stator-rotor magnetic circuit. In the course of the work, analytical calculation methods were applied. As a result of the study, the basic laws of operation were determined, as well as the design and principle of operation of the considered electric motor with a suspended rotation speed.

scholarly journals CONTROLLED TESTING OF BELT TRANSMISSIONS AT DIFFERENT LOADS

2021 ◽  
Vol 2021 (6) ◽  
pp. 5497-5501
Author(s):  
JOZEF MASCENIK ◽  
◽  
SLAVKO PAVLENKO ◽  
Keyword(s):  
Electric Motor ◽  
Analytical Calculation ◽  
Limit States ◽  
Belt Drives ◽  
Extreme Loads ◽  
Extreme Load ◽  
Monitoring And Diagnostics ◽  
Moment Set ◽  
Frequency Inverter

The presented paper provides the alternative options for determining the condition of belt gear based on the testing and monitoring. In order to carry out experimental measurements, a newly developed device for testing, monitoring and diagnostics of belt drives was designed, as well as the possibility of determination of limit states by extreme loads. The designed measuring stand allows to determine the point of destruction of the belt for an extreme load. The process of the belt measurement was to set the predetermined input revolutions of the driving motor by means of the Altivar 71 (FM1) frequency inverter connected to the driving electric motor. The next step in defining the input parameters was to set the load on the driven electric motor. The load on the driven motor was achieved by the torsional moment set by means of the Altivar 71 (FM2) frequency inverter connected to the driven electric motor. In the paper, the analytical calculation is processed. The article mainly points to the innovation of the stand for testing belt transmissions.

scholarly journals SYNCHRONOUS ELECTRIC MOTOR WITH HIGHER SPEED ROTATION AND BALANCED ROTOR

2021 ◽  
pp. 19-26
Author(s):  
Anatoly Yu. Afanasyev ◽  
Valeriy G. Makarov ◽  
Alexey A. Petrov ◽  
Pavel F. Kruglov
Keyword(s):  
Electric Motor ◽  
High Speed ◽  
Rotation Speed ◽  
Supply Voltage ◽  
Structural Features ◽  
Output Shaft ◽  
Stator Winding ◽  
Dynamic Balancing ◽  
High Speed Engine ◽  
Urgent Task

Increasing the speed of rotation of electric motors is an urgent task for turbine mechanisms – pumps, fans, compressors. Traditional synchronous motors have a rotation speed that is less than or equal to the frequency of the supply voltage. The article proposes a design and considers the principle of operation of a synchronous electric motor with double rotation speed. It has three reluctance rotors with one pole, for static and dynamic balancing, and the stator winding is supplied with voltages out of phase by π/6. The proposed design of a synchronous motor with eighteen phases of the stator winding and, with three rotors, the axes of which are offset relative to the axis of rotation of the output shaft. The use of such a design makes it possible to double the rotation speed of the output shaft in comparison with the frequency of the supply voltages. A description of the principle of operation of the motor and its mathematical description are given, taking into account the structural features of the stator-rotor magnetic circuit. The main advantage of the proposed engine in comparison with a high-speed engine is static and dynamic balancing.

DETERMINATION OF THE TYPE OF A SINGLE-USE GRENADE LAUNCHER BASED ON ITS COMPOSITE PARTS AND FRAGMENTS OF REACTIVE GRENADE FOUND AT THE PLACE OF ACCIDENT

2017 ◽  
Vol 17 ◽  
pp. 245-252
Author(s):  
V. V. Somov
Keyword(s):  
Combustion Chamber ◽  
Structural Features ◽  
Outlet Section ◽  
Technical Expertise ◽  
Jet Engine ◽  
Size Ofthe ◽  
Single Use ◽  
Nozzle Block ◽  
Considerable Damage

In carrying out an investigation into the explosion, among others, the investigative version of the use of a single-use reactive grenade launcher is being considered. The most common for criminal explosions are applied grenade launchers RPG-18, RPG-22, RPG-26. Their use is due to a number of such properties as small size and weight, which makes it possible to transfer them covertly, the range of the shot significantly exceeding the range of the hand grenade throw, the high detonating effect of the rocket grenade explosion. The single-use rocket launchers are generally of the same design. Their differences are in the features of the components construction and dimensional characteristics, which are given in the article. On the basis of expert practice, details ofgrenade launchers that remain at the site of the explosion and have the least damage are determined. These details are the objects of investigation of the explosion technical expertise. These objects include launchers of grenade launchers and rocket parts ofjet grenades. The design features of the launchers, their dimensional characteristics and marking symbols make it possible to determine their belonging to a specific type of jet grenade launchers. Missile parts of jet grenades differ in the form of the combustion chamber of the jet engine, nozzle, in the size ofthe outlet section of the nozzle, in the form and size of the stabilizerfeathers. To determine the belonging of the rocket part of the grenade to a specific type ofjet grenade launcher, it’s necessary to establish a set of structural features and dimensional characteristics. At considerable damage of the combustion chamber of the jet engine, as a rule, the nozzle block remains intact that allows to define diameter of critical section of a nozzle, and on it to establish type of the used single-use grenade launcher.

scholarly journals Dispersive evaluation and surface chemistry of advanced, multifunctional silica/lignin hybrid biomaterials

2013 ◽  
Vol 11 (11) ◽  
pp. 1860-1873 ◽  
Author(s):  
Magdalena Nowacka ◽  
Łukasz Klapiszewski ◽  
Małgorzata Norman ◽  
Teofil Jesionowski
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Electrochemical Sensors ◽  
Relevant Information ◽  
Structural Features ◽  
Kraft Lignin ◽  
Morphological Properties ◽  
Wide Range ◽  
Hybrid Biomaterials

AbstractAdvanced silica/lignin hybrid biomaterials were obtained using hydrated or fumed silicas (Aerosil®200) and Kraft lignin as precursors, which is a cheap and biodegradable natural polymer. To extend the possible range of applications, the silicas were first modified with N-2-(aminoethyl)-3-aminopropyltrimethoxsysilane, and then with Kraft lignin, which had been oxidized with sodium periodate. The SiO2/lignin hybrids and precursors were characterised by means of determination of their physicochemical and dispersive-morphological properties. The effectiveness of silica binding to lignin was verified by FT-IR spectroscopy. The zeta potential value provides relevant information regarding interactions between colloid particles. Measurement of the zeta potential values enabled an indirect assessment of stability for the studied hybrid systems. Determination of zeta potential and density of surface charge also permitted the quantitative analysis of changes in surface charge, and indirectly confirmed the effectiveness of the proposed method for synthesis of SiO2/lignin hybrid materials. A particularly attractive feature for practical use is their stability, especially electrokinetic stability. It is expected that silica/lignin hybrids will find a wide range of applications (polymer fillers, biosorbents, electrochemical sensors), as they combine the unique properties of silica with the specific structural features of lignin. This makes these hybrids biomaterials advanced and multifunctional.

Determination of the Structural Features of a Long-Lived Electron-Transfer State of 9-Mesityl-10-methylacridinium Ion

2012 ◽  
Vol 134 (10) ◽  
pp. 4569-4572 ◽  
Author(s):  
Manabu Hoshino ◽  
Hidehiro Uekusa ◽  
Ayana Tomita ◽  
Shin-ya Koshihara ◽  
Tokushi Sato ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Structural Features ◽  
Transfer State

scholarly journals Macroseismic risk classification of historical constructions: the LEXSIS approach

2021 ◽  
Author(s):  
Irene Puncello ◽  
Silvia Caprili ◽  
Elisa Bonanni
Keyword(s):  
Morphological Evolution ◽  
Structural Features ◽  
Structural Behaviour ◽  
Structural Units ◽  
Knowledge Process ◽  
Risk Ranking ◽  
Hazard Parameters ◽  
Specific Evaluation

AbstractThe present paper deals with the elaboration of a methodology to assess the macro-seismic risk of monumental historical buildings, representing a fundamental part of the European cultural assets. Monumental buildings typically arise from a very complex constructive and morphological evolution process characterised by modifications occurred over the centuries. Therefore, they are usually heterogeneous buildings similar to 'structural aggregates' rather than single constructions and characterised by a structural behaviour depending on the mutual interaction of different structural units. An accurate knowledge process can allow the determination of structural units within the complex: such units can be therefore analysed using a specific evaluation form conceived to provide a 'risk ranking' of the different portions constituting the aggregate and accounting for vulnerability, exposure and seismic hazard parameters. The proposed methodology exploits what is already used to quickly determine structural features and eventual damages in the post-earthquake phase for ordinary buildings, introducing specific aspects typical of historical-cultural heritage requiring attention. According to the results achieved, retrofit interventions or deepen investigations can be planned for units provided by a higher position in the risk scale, optimising and rationally planning the use of available economic and time resources. In the present work, the proposed methodology is applied to the monumental complex of the Certosa di Calci, Pisa (Italy).

scholarly journals Development of a high-quality brushless dc electric drive systems model

Vestnik IGEU ◽  
2020 ◽  
pp. 31-45
Author(s):  
T.H. Abuziarov ◽  
A.S. Plehov ◽  
A.B. Dar’enkov ◽  
A.I. Ermolaev
Keyword(s):  
Electric Drive ◽  
Electric Motor ◽  
Permanent Magnets ◽  
Structural Features ◽  
Bldc Motor ◽  
Electric Drives ◽  
Brushless Dc ◽  
Systems Model ◽  
Semiconductor Converter ◽  
Torque Pulsations

When designing electric drives based on brushless DC motors with permanent magnets (BLDC), which have low level torque pulsations, the problem of modelling non-standard topological solutions appears. The known models of BLDC motors are either based on the assumptions about the symmetry of the stator pa-rameters of the electric motor and/or the ideal form of the phase back-EMF waveform, which reduce the accuracy of evaluating the effectiveness of the proposed solutions or prove unusable for modelling an operation of the electric motor with a non-standard semiconductor converter. It is necessary to develop a mathematical model of the BLDC motor-based electric drive that takes into account the structural features of the electric motor and allows for semiconductor converter configuration variability. The model is designed in the Matlab Simulink environment. The verification is carried out by comparing the modelling results with experimental data obtained previously by other researchers. The proposed method for generating phase back-EMF in the BLDC motor model provides the possibility for the user to set the EMF form templates independent for each phase. The proposed method for stator circuit simulating provides the user with access to each of the stator windings leads as well as with the possibility of asymmetric determination of each parameter of the electric motor. Upon verification, it has been shown that the difference in the control points between the simulated and experimental speed-torque curves does not exceed 3,5 %. The developed model allows analyzing the static and dynamic characteristics of operation modes of non-standard topology BLDC motor-based electric drives taking into account the stator pa-rameters asymmetry and the real phase back-EMF waveform. The specified features of the model allow exploring the operation of the designed electric drive, taking into account the BLDC motor and converter design. The model can be applied when checking atypical design decisions and when changing the set parameters of the electric drive and restrictions on working conditions and target functions to refine the control system algorithms and automate the search for optimal parameters of the motor and the semiconductor converter.

scholarly journals New sorbents for electrochromatography based on polymer-inorganic dielectric composites

2021 ◽  
Vol 2103 (1) ◽  
pp. 012124
Author(s):  
A Y Shmykov ◽  
S V Mjakin ◽  
N A Bubis ◽  
L M Kuztetzov ◽  
N A Esikova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Filler Content ◽  
Structural Features ◽  
Polymer Binder ◽  
Dielectric Losses ◽  
Infinite Cluster ◽  
Confocal Scanning ◽  
Scanning Electron

Abstract Oligomeric diisocyanate based coatings with different contents of barium titanate (BaTiO3) submicron sized particles as a ferroelectric filler are synthesized on poly(dimethylsiloxane) (PDMS) supports. The study of thus obtained coatings using confocal scanning electron microscopy allowed the characterization of their morphology and features of BaTiO3 particles distribution in the polymer binder, including the determination of threshold filler contents corresponding to the formation of an infinite cluster, matrix-island and chain-like structures as well as the percolation. Dielectric permittivity and dielectric losses of the composites are measured and studied depending on BaTiO3 filler content and relating structural features.

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