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1

Determination of the friction force between the draw rod and its guide in sucker rod well pumps and an analytical study of the stress deformation state of the valve assembly

Aliyeva Sevda Y., Abbasov Sakit H.

Nafta-Gaz

|

2023

|

R. 79, nr 9

596--603

EN

The article is devoted to the determination of the friction force between the draw rod and the guide and to the analytical study of the stress deformation state of the valve assembly of the rod well pump. In sucker rod well pumps, a hollow cylindrical guide is used to ensure the same axis of the plunger as the cylinder during operation. The guide is attached to the upper end of the pump cylinder. The draw rod connecting the sucker rod and the plunger of the pump moves up and down in the internal cylindrical cavity of the guide in the corresponding movements of the balancer head. There must be a certain clearance between the draw rod and the guide to ensure free movement of the draw rod. Based on the calculation scheme for determining the friction force between the draw rod and the guide is given, and the necessary parameters are determined. According to the values obtained from the calculation, the graphs were built based on the dependences of the friction force between the draw rod and the guide on the angle φ, and on the path of the plunger when φ = 30. At the same time, according to the calculation scheme of the "ball-saddle" pair, the force acting on the ball, the stresses generated on the contact surfaces of the ball and the saddle, and other parameters were found. The friction and wear between the draw rod and the guide is also typical of the friction and wear between the polished rod and the wellhead forming structure. Because, in the latter case, as a result of the suspension point of the balancer head not having the same axis as the wellhead, the polished rod cannot move with the straight axis in wellhead valve.

PL

Artykuł zawiera opis metody wyznaczania siły tarcia pomiędzy cięgłem a prowadnicą cięgła dławikowej pompy wgłębnej oraz analizę odkształcenia naprężeniowego zespołu zaworowego pompy. W żerdziowych pompach wgłębnych stosuje się drążone cylindryczne prowadnice w celu zapewnienia współosiowości nurnika i cylindra pompy. Prowadnica ta jest przymocowana do górnej końcówki cylindra pompy. Cięgło stanowi połączenie żerdzi pompowej z nurnikiem pompy. Porusza się ono w górę i w dół w cylindrycznej prowadnicy, zgodnie z ruchem głowicy wyważającej. Pomiędzy cięgłem a prowadnicą należy zapewnić odpowiedni luz tak, aby zapewnić swobodny ruch cięgła. Wszelkie niezbędne parametry układu ustalono na podstawie schematu obliczeniowego siły tarcia występującego pomiędzy cięgłem a prowadnicą. Na podstawie wartości uzyskanych podczas obliczeń utworzono wykresy obrazujące zależności siły tarcia pomiędzy cięgłem a prowadnicą dla kąta φ oraz dla toru posuwu nurnika, gdy φ = 30. Jednocześnie, zgodnie ze schematem obliczeniowym pary „kula–gniazdo”, wyznaczono siłę działającą na kulę, naprężenia powstające na powierzchniach styku kuli i gniazda oraz inne parametry. Tarcie i zużycie pomiędzy cięgłem a prowadnicą jest również typowe dla tarcia i zużycia występujących pomiędzy drążkiem polerowanym a prowadnicą w zagłowiczeniu odwiertu. W tym drugim przypadku ze względu na to, że punkt zawieszenia głowicy wyważającej nie znajduje się w osi głowicy odwiertu, drążek polerowany nie może się poruszać w osi zaworu głowicy odwiertu.

2

Machine learning models for cracking torque and pre‑cracking stiffness of RC beams

Shenggang Chen, Quanquan Guo, Yingying Zhang, Hexiang Hu, Bei Shen

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 1

art. no. e6, 2023

EN

The torsional behavior of RC beams is a complex work involving interactions of different design parameters and mechanisms. Considering the limitations and lower accuracy of traditional calculation theories, two machine learning models, including artificial neural network (ANN) model and random forest (RF) model, were applied for the frst time to predict the cracking torque and initial or pre-cracking torsional stiffness of RC beams. A comprehensive database consisting 159 experimental results of RC beams with solid or hollow sections was compiled, with input variables including dimension parameters of cross-section, compressive stress of concrete, elastic modulus and strength ratio of reinforcements. The performance of the models was appraised by various statistical estimators and safety ratio, and compared with different theories for cracking torque and initial stiffness. Among all the calculation models, RF model achieved the best overall prediction performance with the highest coeffcient of determination (R2=0.985 for cracking torque and R2=0.978 for initial stifness) and lowest root-mean-square error (RMSE=5.867 for cracking torque and RMSE=3.994 for initial stiffness). However, theories for cracking torque, i.e., plastic theory, Bredt thin-tube theory and skew-bending theory, gave huge underestimation, whereas greatly exaggerated initial stiffness was obtained by elastic theory and simplified soften membrane model for torsion theory. Besides, input variable importance analysis was conducted, revealing that dimension parameters of cross-section were the most critical features to decide prediction performance for pre-cracking torsional performance of RC beams. The achievements of this paper may provide references to the establishment of new predicting model for pre-cracking torsional response of RC beams.

3

Load capacity and design parameters of ball-type safetyoverrunning clutch with inclined grooves sides

Protsenko Vladyslav, Malashchenko Volodymyr, Kłysz Sylwester, Nastasenko Valentyn, Babiy Mykhaylo, Avramenko Oleksiy

Diagnostyka

|

2022

|

Vol. 23, No. 4

art. no. 2022403

EN

Article deals with safety-overrunning clutches for mechanical transmissions. Modern design of safetyoverrunning clutch with grooves sides inclined to semi-coupling radius has been described and researched in the article. It has practical value for creation modular-type machines. On the basis of the theoretic studies, the expressions for obtaining the main specific operation parameters have been proposed: rating torque, beginning and ending operation torques. As the result of the studies, the equations for estimation the clutch main operation characteristics have been received - rating torque exceeding coefficient, coefficients of clutch accuracy and sensitivity. On account of modeling and comparison with clutch where grooves sides are parallel to the radius made a number of important conclusions. The analysis performed demonstrates that clutches with inclined to radius grooves sides in general have higher operation characteristics compared with clutches with parallel to radius grooves sides, particularly higher accuracy coefficient and lower rating torque exceeding coefficient. Obtained results make it possible to recommend for highly loaded large-mass systems clutches with low values of grooves to clutch axe and grooves sides to radius inclination angles, because it provides balls contact with plane sides grooves surfaces and through this allows to decrease contact stresses compared with clutches with grooves sides parallel to radius; allows to provide high load capacity with low rating torque exceeding in overload mode; in clutches with inclined to radius grooves sides friction impact manifests less in operation with high rotation frequency.

4

Pomiar momentu obrotowego jako kryterium realizacji procesu granulacji talerzowej

Rostocki Andrzej, Ławińska Katarzyna, Modrzewski Remigiusz, Hejft Roman, Derbiszewski Bogdan, Obraniak Andrzej

Technologia i Jakość Wyrobów

|

2021

|

R. 66

159--169

PL

W pracy badano zmiany momentu obrotowego podczas granulacji drobnego materiału (bentonitu odlewniczego) w granulatorach talerzowych przy zmieniających się parametrach procesowych i aparaturowych. Złoże materiału sypkiego natryskiwano w trakcie dozowania, przy stałym natężeniu przepływu cieczy Q=0,5*10-3 dm3/s za pomocą zraszacza, który zapewniał równomierne podawanie cieczy natryskowej. Proces granulacji prowadzono każdorazowo aż do całkowitego zwilżenia materiału w aparacie. Przez cały czas trwania procesu rejestrowano chwilowe wartości momentu obrotowego na wale granulatora. Momenty jednostkowe (zredukowane) M* (na jednostkę masy nasypowej) wyznaczono na podstawie zmierzonych wartości, uwzględniając moment jałowy oraz zmiany masy nasypowej w talerzu. Stwierdzono, że parametry procesu i aparatury miały istotny wpływ na funkcję M* = f(t). Wiąże się to ze zmieniającymi się właściwościami zwilżonego złoża i granulatu, od których zależy charakter ruchu złoża, a co za tym idzie moment niezbędny do pochylenia złoża i wywołania jego cyrkulacji niezbędnej do wywołania mechanizmów tworzenia i wzrostu aglomeratów.

EN

The study investigated changes in torque during granulation of fine material (foundry bentonite) in disc granulator with changing process and apparatus parameters. The bed of loose material was sprayed during dosing, at a constant liquid flow rate Q = 0,5*10-3 dm3/s with the use of a sprinkler, which ensured even distribution of the spraying liquid. The granulation process was carried out each time until the material was completely wetted in the apparatus. Throughout the process, the instantaneous values of the torque on the granulator shaft were recorded. The unit moments M * (per unit of bulk mass) were determined on the basis of the measured values, taking into account the idle moment and changes in the bulk mass in the plate. It was found that the process and apparatus parameters had a significant influence on the function M * = f (t). This is related to the changing properties of the wetted bed and granulate, on which the nature of the bed's movement depends, and thus the moment necessary to tilt the bed and induce its circulation necessary to induce the mechanisms of formation and growth of agglomerates.

5

Three-bladed horizontal axis water turbine simulations with free surface effects

Rodríguez L., Benavides-Moran A., Laín S.

International Journal of Applied Mechanics and Engineering

|

2021

|

Vol. 26, no. 3

187--197

EN

The water level above a hydrokinetic turbine is likely to vary throughout the season and even along the day. In this work, the influence of the free surface on the performance of a three bladed horizontal-axis turbine is explored by means of a three-dimensional, transient, two-phase flow computational model implemented in the commercial CFD software ANSYS Fluent 19.0. The [...] Transition turbulence model coupled with the Volume of Fluid (VOF) method is used to track the air-water interface. The rotor diameter is [...]. Two operating conditions are analyzed: deep tip immersion (0.55D) and shallow tip immersion (0.19D). Three tip speed ratios are evaluated for each immersion. Simulation results show a good agreement with experimental data reported in the literature, although the computed torque and thrust coefficients are slightly underestimated. Details of the free surface dynamics, the flow past the turbine and the wake near the rotor are also discussed.

6

Predictive torque control of induction motor drive with reduction of torque and flux ripple

Kiani Babak, Mozafari Babak, Soleymani Soodabeh, Mohammadnezhad Shourkaei Hosein

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2021

|

Vol. 69, nr 4

art. no. e137727

EN

The continuing efforts for reduction of the torque and flux ripples using Finite Set Model Predictive Direct Torque Control methods (FS-MPDTC) have been currently drowning a great attention from the academic communities and industrial applications in the field of electrical drives. The major problem of high torque and flux ripples refers to the consideration of just one active voltage vector at the whole control period. Implementation of two or more voltage vectors at each sampling time has recently been adopted as one of the practical techniques to reduce both the torque and flux ripples. Apart from the calculating challenge of the effort control, the parameter dependency and complexity of the duty ratio relationships lead to reduction of the system robustness. those are two outstanding drawbacks of these methods. In this paper, a finite set of the voltage vectors with a finite set of duty cycles are employed to implement the FS-MPDTC of induction motor. Based on so-called Discrete Duty Cycle- based FS-MPDTC (DDC-FS-MPDTC), a base duty ratio is firstly determined based on the equivalent reference voltage. This duty ratio is certainly calculated using the command values of the control system, while the motor parameters are not used in this algorithm. Then, two sets of duty ratios with limit members are constructed for two adjacent active voltage vectors supposed to apply at each control period. Finally, the prediction and the cost function evaluation are performed for all of the preselected voltage vectors and duty ratios. However, the prediction and the optimization operations are performed for only 12 states of inverter. Meanwhile, time consuming calculations related to SVM has been eliminated. So, the robustness and complexity of the control system have been respectively decreased and increased, and both the flux and torque ripples are reduced in all speed ranges. The simulation results have verified the damping performance of the proposed method to reduce the ripples of both the torque and flux, and accordingly the experimental results have strongly validated the aforementioned statement.

7

Study of the two-rotor electric motor of a drive of vehicle drive wheels

Sergienko Nikolay, Kuznetsov Valeriy, Liubarskyi Borys, Pastushchina Mariia, Gołębiowski Piotr, Tkaczyk Sławomir

Archives of Transport

|

2021

|

Vol. 60, iss. 4

245--257

EN

In recent years, electric and hybrid vehicles have taken more and more attention due to their apparent advantages in saving fuel resources and reducing harmful emissions into the environment. Even though electric vehicles can solve the ecological problem, their operation is faced with a number of inconveniences associated with a limited driving distance from a single charge due to limited storage of energy from an independent power source and a lack of the required service and repair infrastructure. In hybrid and electric vehicles one of the main parameters is the curb weight, which affects energy consumption, vehicle speed, stability, controllability and maneuverability. In this regard, leading car manufacturers use parts with a low specific weight (non-metallic, aluminum alloys, etc.) in the design and also exclude some units from the design. Due to these technical solutions, the vehicle's operating is improved. One of the groups of parameters to be defined when designing a new electric vehicle is the parameters relating to the electric motor. The purpose of the article is determination of the mechanical characteristics of a two-rotor electric motor during magnetic flux control and assessment of the possibility of organizing the drive of the drive wheels of the vehicle. The electric motor has two mechanically independent outputs. For the study, an electrical equivalent diagram has been developed for the given two-rotor electric motor. A simulation model of the equivalent diagram has been built. Simulating the interaction processes of the rotors with the stator made it possible to obtain data for building the mechanical characteristics for each output of the electric motor. Analysis and processing of the mechanical characteristics data of the electric motors showed the conformity and the range of changes in the torque on each of the rotors when changing their slip and revolution, which are required when building algorithms for the operation of electric motor control systems as part of drives for various purposes. Analysis of the simulation results made it possible to assess the possibility of using the considered two-rotor electric motor for the drive of drive wheels in an electric and hybrid wheeled vehicle.

8

Optimum combination of machining parameters during drilling of aluminium 7075 alloys using Grey based Taguchi approach

Sreenivasulu Reddy, Rao Chalamalasetti Srinivasa

Journal of Mechanical and Energy Engineering

|

2020

|

Vol. 4, No 3

227--238

EN

From ancient days to till today manufacturing industries, especially making of holes on the parts during drilling process for precision assembling of parts facing problems with burr formation. Drilling operation is one of the finishing operation in the production cycle, removing of burrs during drilling process is a time consuming and non-value added process to the manufacturing sector. So reducing the size of burrs is the main aim of the present study. In the present work, optimization of burr size is considered during drilling of aluminium 7075 alloy. In this connection, experiments are conducted based on Grey based Taguchi. From Grey relational grades of responses selected optimal combination of parameters to attain multiple performance characteristics of responses with a corresponding higher grey relational grade. For identifying the most significant input parameters that influence the output responses ANOVA is conducted. Based on interaction effect plots of data means of responses from results of ANOVA, confirmation tests are conducted by choosing most significant parameters. Finally, observations reveals that feed rate, point and clearance angles are the most influential factors on burr size and also experimental results divulge that the lower the thrust force causes to decrease the burr height. The proposed approach is helpful to the budding entrepreneurs in the related areas to select optimal combination of drilling parameters to attain multiple performance characteristics of responses especially in burr size to prevent the post finishing operations up to certain extent.

9

Stress Concentration Analysis of the Injection Pump Shaft

Bałon Paweł, Świątoniowski Andrzej, Rejman Edward, Kiełbasa Bartłomiej, Smusz Robert, Szostak Janusz, Kowalski Łukasz

Advances in Science and Technology. Research Journal

|

2020

|

Vol. 14, no 2

155--162

EN

The paper presents the methodology for designing the injection shaft drive for diesel engines with 2,3,4,6 and 8 cylinders as well as power from 2.5 to 52 kW per cylinder using the FEM method and experimental research. The pump is the original solution of the authors. The shaft is a basic part of the pump with a complex structure. In order to assess the state of stress in the shaft, the FEM analytical method was used and experimental tests were carried out, subjecting the shaft to torsional moment resulting from the transmitted power. Experimental studies confirmed the results of numerical calculations and the correctness of the adopted solution. The destructive tests were carried out to assess the maximum load capacity of the shaft, loading it with an increasing torque until visible plastic deformations occurred. This condition appeared at twice the moment (Ms = 602 Nm) in relation to the maximum predicted moment in operation (extreme operating conditions of the pump shaft). The theoretical studies confirmed very significant stress concentration (αk coefficient at the level of 2.63 or even 4.7), which may be the cause of fatigue cracks. It also determines the strength of the shaft and its torsional stiffness, which influences the proper functioning of the pump and ensures adequate fuel injection phases.

10

Muscle torque production and kinematic properties in post-stroke patients: a pilot cross-sectional study

Kowal Mateusz, Kołcz Anna, Dymarek Robert, Paprocka-Borowicz Małgorzata, Gnus Jan

Acta of Bioengineering and Biomechanics

|

2020

|

Vol. 22, no. 1

11--20

EN

Stroke-related hemiplegia is an important factor influencing parameters of gait. So far, limited papers have assessed temporo-spatial capabilities and their correlations with gait parameters in the early post-stroke stage. This pilot study evaluated the temporospatial parameters of gait and assessed the maximal isometric and isokinetic torque production of the plantar flexor and dorsiflexor muscles. Methods: 15 patients with lower limb spasticity and 15 healthy controls were included. Stroke severity was assessed using the Modified Ashworth Scale and the Barthel Index. Gait cadence, gait speed, and gait cycle were assessed using inertial sensors during a Timed Up and Go test. Maximal isometric and isokinetic torque production of the ankle plantar flexor and dorsiflexor muscles were assessed using an isokinetic dynamometer device. Results: Post-stroke patients had statistically significantly lower gait cadence than healthy participants (17%, p < 0.05). Statistically significantly lower values of vertical acceleration were also noted during a sit-to-stand movement task (42%, p < 0.05). Plantar flexion torque of the affected limb was significantly different during isometric (63%, p ≤ 0.01) and isokinetic work for 30o /s (49%, p = 0.04), 60o /s (58%, p = 0.01) and 20 °/s (53%, p = 0.01). Dorsiflexor muscles’ torque production was significantly different in isometric activity (38%, p = 0.04). A statistically significant positive correlation occurred between the absolute peak torque of the dorsiflexor muscles in both static and speed phases of gait (Rs = 0.65, p = 0.04). Conclusions: Despite the low intensity of spasticity and early phase after stroke, differences in the muscle torque production and temporo-spatial parameters, as well as the correlations between them, were noticeable.

11

Niedoceniany wpływ błędów montażowych na nośność stalowych łączników rozporowych

Konieczny Kazimierz, Dudek Daniel

Przegląd Budowlany

|

2019

|

R. 90, nr 7-8

75--79

PL

W artykule opisano wpływ najczęściej popełnianych błędów w trakcie montażu stalowych łączników rozporowych na nośność zamocowań. Zazwyczaj wynika to z zarysowań podłoża betonowego, użycia wierteł o niewłaściwej średnicy, zastosowania nieodpowiedniego momentu instalacyjnego, zbyt płytkiego osadzenia łączników w podłożu itp. Stwierdzone w badaniach różnice w nośności mogą dochodzić nawet do 200%.

EN

The paper describes the effects of errors most frequently met while installing the metal anchors on the bearing capacity of the fixing system. It is usually caused by cracks of the concrete base, usage of drills with incorrect diameters, application of improper installation torque and/or too shallow embedment of anchors in the concrete base, and also other factors. The differences in the capacity found in the tests can reach even 200%.

12

An experimental study of cutting fluid on drilling AISI 1040 steel

Alim Md. Abdul, Uddin Md. Julhash, Islam Md. Ariful

Journal of Mechanical and Energy Engineering

|

2019

|

Vol. 3, No 1

7--12

EN

This experimental study investigated the effects of a conventional cutting fluid during drilling cylindrical holes on workpiece materials made of the AISI 1040 steel. Drilling responses were compared between dry and wet (in presence of the cutting fluid) cutting conditions with respect to drilling force, roundness deviation and taper of the hole, and chip morphology. High production machining and drilling with high cutting speed, feed, and depth of cut were found to be inherently associated with the generation of a large amount of heat and high cutting temperature. In a dry condition such high cutting temperature not only reduces dimensional accuracy and tool life but also impairs the roundness deviation and taper of the hole. The use of a conventional cutting fluid, in such a situation, was very effective to reduce the cutting temperature. In a dry cutting condition, numerous tool-wears were found on the drill bits. Drilling in such a dry condition seriously affects roundness of the hole, and chip shape and color. Contrastingly, use of a traditional cutting fluid reduced temperature as well as improved roundness and taper of the hole. It also acted as a lubricate at the tool tip–work surface interface. Overall, the conventional cutting fluid enhanced the quality of the machine work and potentially can increase machine life of drill bits.

13

Driving energy management of front-and-rear-motor-drive electric vehicle based on hybrid radial basis function

Sun Binbin, Zhang Tiezhu, Ge Wenqing, Tan Cao, Gao Song

Archives of Transport

|

2019

|

Vol. 49, iss. 1

47--58

EN

This paper presents mathematical methods to develop a high-efficiency and real-time driving energy management for a front-and-rear-motor-drive electric vehicle (FRMDEV), which is equipped with an induction motor (IM) and a permanent magnet synchronous motor (PMSM). First of all, in order to develop motor-loss models for energy optimization, database of with three factors, which are speed, torque and temperature, was created to characterize motor operation based on HALTON sequence method. The response surface model of motor loss, as the function of the motor-operation database, was developed with the use of Gauss radial basis function (RBF). The accuracy of the motor-loss model was verified according to statistical analysis. Then, in order to create a two-factor energy management strategy, the modification models of the torque required by driver (Td) and the torque distribution coefficient (β) were constructed based on the state of charge (SOC) of battery and the motor temperature, respectively. According to the motor-loss models, the fitness function for optimization was designed, where the influence of the non-work on system consumption was analyzed and calculated. The optimal β was confirmed with the use of the off-line particle swarm optimization (PSO). Moreover, to achieve both high accuracy and real-time performance under random vehicle operation, the predictive model of the optimal β was developed based on the hybrid RBF. The modeling and predictive accuracies of the predictive model were analyzed and verified. Finally, a hardware-in-loop (HIL) test platform was developed and the predictive model was tested. Test results show that, the developed predictive model of β based on hybrid RBF can achieve both real-time and economic performances, which is applicable to engineering application. More importantly, in comparison with the original torque distribution based on rule algorithm, the torque distribution based on hybrid RBF is able to reduce driving energy consumption by 9.51% under urban cycle.

14

Buckling of moderately thick annular plates subjected to torque

Bagheri Hamed, Kiani Yaser, Eslami Mohammad Reza

Archive of Mechanical Engineering

|

2019

|

Vol. LXVI, nr 2

209--227

EN

An attempt is made in the current research to obtain the fundamental buckling torque and the associated buckled shape of an annular plate. The plate is subjected to a torque on its outer edge. An isotropic homogeneous plate is considered. The governing equations of the plate in polar coordinates are established with the aid of the Mindlin plate theory. Deformations and stresses of the plate prior to buckling are determined using the axisymmetric flatness conditions. Small perturbations are then applied to construct the linearised stability equations which govern the onset of buckling. To solve the highly coupled equations in terms of displacements and rotations, periodic auxiliary functions and the generalised differential quadrature method are applied. The coupled linear algebraic equations are a set of homogeneous equations dealing with the buckling state of the plate subjected to a unique torque. Benchmark results are given in tabular presentations for combinations of free, simply-supported, and clamped types of boundary conditions. It is shown that the critical buckling torque and its associated shape highly depend upon the combination of boundary conditions, radius ratio, and the thickness ratio.

15

Research and development of an electric traction drive based on a switched reluctance motor

Buriakovsky S., Maslii A., Pasko O., Denys I.

Transport Problems

|

2018

|

T. 13, z. 2

69--79

EN

In the most developed countries, intensive studies are being carried out to utilize various types of electric machines such as synchronous motors with permanent magnets and traction motors with non-traditional magnetic systems on traction electric drives. Switched Reluctance Motors (SRM) are one of the most simple, reliable, and cost-efficient technology used in manufacture and operation. Its convenient traction performance, combined with the high overload capacity, makes its use promising for both freight and passenger rolling stock. Our research is directed to develop a control system for a four-phase SRM. The procedure of fuzzy-regulator synthesis is presented. A physical model of a switched reluctance drive is created, namely, it is a system of a wheel set and a motor. The efficiency of the control system with different types of speed regulators was checked and their main quality indicators were determined. According to the results of the analysis, it was found that the fuzzy regulator more precisely controls the regulated value.

16

Diagnostic aspects of a crankshaft torsional oscillations monitoring by IAS measurement

Dereszewski M.

Journal of KONES

|

2018

|

Vol. 25, No. 1

67--74

EN

Continuous monitoring of diesel engine performance under its operating is critical for prediction of malfunction development and subsequently functional failure detection. Analysis of Instantaneous Angular Speed (IAS) of the crankshaft is considered as one of non-intrusive and effective method of detection of combustion quality deterioration. The article contains presentation of attempt of monitoring of piston engine’s crankshaft torsional vibrations by measurement of Instantaneous Angular Speed at free, and power output ends of the engine’s crankshaft. The angular speed measurements was done using two optical sensors for reading the IAS, mounted at shaft line’s opposite ends, one at free end of the crankshaft and second at end of generator’s shaft. In the article is presented description of the measurement system and explanation of its mode of work. Experiments were based at two kinds of malfunction possible to be simulated at test bed. First one was simulation of a leak of fuel injection pump, the second one relayed on mounting of sets of injection valves with different nozzles characteristics (spraying nozzle angle), giving different parameters of fuel injection. Presented results of experiment derives from test cycle carried out using laboratory stand of Gdynia Maritime University equipped with 3- cylinder self − ignition engine, powering electric generator.

17

Badanie wpływu ugięcia wstępnego na promień wyrobu w procesie gięcia kątownika na giętarce trójrolkowej

Usydus I., Tofil A., Gontarz A.

Hutnik, Wiadomości Hutnicze

|

2018

|

Vol. 85, nr 7

223--226

PL

W artykule przedstawiono analizę wpływu zmiany kąta kształtującego α na wartości parametrów siłowych w procesie walcowania skośnego. Przeprowadzona symulacja numeryczna kształtowania odkuwki stopniowanego wału umożliwiła przedstawienie rozkładów siły promieniowej i osiowej, jak również rozkładu momentu obrotowego działających na rolkę stożkową w zależności od ustalonego kąta kształtującego α.

EN

The paper presents a numerical investigation of the effect of the forming angle α value change on force parameters in a skew rolling process. The MES simulation of forming the stepped shaft allows for the presentation of radial and axial force distributions, as well as the distribution of torque acting on the conical roller, depending on the determined forming angle α.

18

Analiza numeryczna wpływu kąta kształtującego na parametry siłowe w procesie walcowania skośnego wałka stopniowanego

Lis K., Pater Z.

Hutnik, Wiadomości Hutnicze

|

2018

|

Vol. 85, nr 7

219--222

PL

W artykule przedstawiono analizę wpływu zmiany kąta kształtującego α na wartości parametrów siłowych w procesie walcowania skośnego. Przeprowadzona symulacja numeryczna kształtowania odkuwki stopniowanego wału umożliwiła przedstawienie rozkładów siły promieniowej i osiowej, jak również rozkładu momentu obrotowego, działających na rolkę stożkową, w zależności od ustalonego kąta kształtującego α.

EN

The paper presents a numerical investigation of the effect of the forming angle α value change on force parameters in a skew rolling process. The MES simulation of forming the stepped shaft allows for the presentation of radial and axial force distributions, as well as the distribution of torque acting on the conical roller, depending on the determined forming angle α.

19

Torque ripple calculation of two-phase im supplied by three-leg VSI inverter

Záskalický P.

Maszyny Elektryczne : zeszyty problemowe

|

2017

|

Nr 3 (115)

13--17

EN

The proposed paper deals with steady state estimation of a electromagnetic torque ripples and a current waveform of a two-phase induction motor (IM), which is supplied by an three-leg voltage source IGBT bridge connected inverter (VSI). The complex Fourier series analysis of the inverter’s output voltage was made, to obtain an analytical formula of supply voltage waveform. The space phasor theory has been applied to the two-phase induction machine model to obtain electromagnetic torque and supply current waveforms for various operation states.

20

Operational characteristics of rotating magnetoreological clutches and brakes

Bajkowski J.

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2017

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no. 3

7--12

EN

The following article is devoted to research on particular operational characteristics of prototypes of rotating magnetorheological clutches and brakes. The experiments were conducted on a specialized test stand, including a high power servo-motor, torque meters, and thermal sensors. In addition to the generally determined relationship of the clutch or brake torque transmitted over time and depending on the electric current, it has been shown that the particular operational characteristics of these devices are necessary for the full operational picture of the performance of the device. These are, among others, the torque versus rotational speed, temperature, and operational time dependencies.

PL

Praca poświęcona jest badaniom prototypów sprzęgieł i hamulców magnetoreologicznych pracujących w ruchu obrotowym. Zostały one przeprowadzone na specjalistycznym stanowisku badawczym. Obok powszechnie wyznaczanych zależności przenoszonego momentu obrotowego sprzęgła lub hamulca w funkcji czasu i w zależności od wartości natężenia prądu płynącego w solenoidach tych urządzeń i sterującego natężeniem pola magnetycznego wytwarzanego wokół cieczy magnetoreologicznej wykazano, że do pełnego obrazu eksploatacyjnych warunków pracy niezbędne jest wyznaczenie dodatkowych charakterystyk tych urządzeń. Są nimi między innymi wyznaczane w pracy charakterystyki ilustrujące zależności momentu obrotowego w funkcji obrotów, temperatury i inne.