scholarly journals Testing Device for Hydraulic Rope System Tensile Force Equalizing Unit

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Leopold Hrabovský ◽  
Karel Frydrýšek

Abstract Rope elevators, also referred to as traction elevators, have a cabin suspended from a system of ropes. The system of ropes consists of at least two load-bearing steel ropes with six strands or, from the point of view of easier bending, and currently more widespread, ropes with eight strands. Lifting or lowering of the car, run between the guides, is ensured by the frictional force of the steel ropes in the grooves of the traction disk of the elevator machinery. As the load-bearing capacity of the elevator increases, the required number of load-bearing ropes also increases, especially in the case where small diameter ropes are used in traction elevators. The actual weight of the car and the weight of the load must be evenly distributed among all supporting ropes that are used in the given layout of the elevator. Currently, several principles are known by which it is possible to detect and also change the values of the instantaneous magnitudes of the tensile forces acting in a system of ropes. The paper describes the principle of operation of hydraulic balancing of tensile forces in the system of supporting ropes, which uses the laws of hydromechanics and knowledge of pressure transfer to any place in the fluid, known as Pascal's law. Balancing of differently set values of tensile forces in three supporting ropes, to values of the same size, can be simulated on a test device. This presents the correct operation of the hydraulic system and the possibility of balancing tensile forces in the system of supporting ropes described by the principle of hydraulic device.

2021 ◽  
Vol 29 (1) ◽  
pp. 59-64
Author(s):  
Leopold Hrabovsky ◽  
David Borovsky

AbstractThe paper describes the structural design of a laboratory device that allows for presenting operation, simulating work procedures and checking functionality of the elevator “rope sensors” when equalizing different tensile forces in partial ropes of a rope system of traction elevators. The laboratory device is modified for checking operations of commonly used rope sensors. In an overwhelming number of cases, elevator technicians use them for setting up the unequally distributed tensile forces in elevator ropes. The device is equipped with three, mutually attached pulleys, over which the rope is installed. The unknown tensile force in the rope is determined by an “indirect method”, i.e. from the resultant of the forces of the rope bent over the pulleys, which have an effect on the force sensor. The tensile force along the rope axis can be determined numerically, but also experimentally, from the inclination angle of the rope installed on the pulleys, diameter of the pulleys, diameter of the rope and the force detected by the force sensor of the stretched rope. The paper presents experimentally obtained tensile force values at the rope sensor, deduced from stretching the rope. The paper also describes the procedure for determining the measured load in the rope by rope sensors of the SWR, SWK and RMT-1 types based on the variable axial force in the rope.


Author(s):  
Ирина Викторовна Евстафьева

В статье исследуются вопросы попечительства в отношении несовершеннолетних, отбывающих наказание в виде лишения свободы. Проблема, поднимаемая автором настоящей статьи, многогранна, касается различных аспектов отбывания наказания несовершеннолетними в воспитательных колониях и требует комплексного исследования, способного ответить на определенно значимый вопрос: является ли колония законным представителем находящихся в ней несовершеннолетних со всеми вытекающими из статуса законных представителей последствиями. При этом необходимо обращать внимание на специфику правового статуса лиц, отбывающих наказание в воспитательных колониях, которые, во-первых, являются несовершеннолетними, то есть не обладают дееспособностью в полном объеме и нуждаются в особой заботе, защите и представительстве, а во-вторых, осуждены за совершение тяжкого или особо тяжкого преступления, влекущего изоляцию от общества и определенные ограничения и лишения. Отечественное законодательство достаточно детально регламентирует особенности режима отбывания наказания в виде лишения свободы несовершеннолетними, не определяя при этом статуса воспитательных колоний, кем они являются: воспитателями, попечителями или исключительно учреждениями исполнения наказаний. Между тем правильное понимание значения и роли воспитательной колонии в жизни находящихся в ней несовершеннолетних преступников, по мнению автора, поможет избежать ряда проблем, объективно складывающихся в учреждениях подобного рода. С этой точки зрения предлагаемая тема представляет интерес не только для ученых-теоретиков, но и для практиков - сотрудников соответствующих учреждений. Особо следует подчеркнуть, что исследований по данной тематике в специальной литературе нет. Отдельные исследования, встречающиеся в современной литературе, касаются исключительно общего гражданско-правового статуса несовершеннолетних осужденных. Однако это обстоятельство может свидетельствовать только о новизне данной темы, но никак не об отсутствии самой проблемы. The article analyzes the issues of the status of educational colonies as guardians of minors serving a sentence of imprisonment. In fact, the problem raised by the author of this article is multifaceted, concerns various aspects of the serving of punishment by minors in educational colonies and requires a comprehensive study that can answer, it seems, a definitely significant question: whether the colony is the legal representative of the minors in it with all the consequences arising from the status of legal representatives in the form of duties and responsibilities. At the same time, it seems, it is necessary to pay attention to the specifics of the legal status of citizens serving sentences in educational colonies, who, firstly, are minors, i.e. do not have full legal capacity and need special care, protection and representation, and, secondly, are convicted of committing a serious or particularly serious crime, entailing isolation from society and certain restrictions and deprivation. Domestic legislation regulates in sufficient detail the peculiarities of the regime of serving sentences in the form of deprivation of liberty by minors, without determining the status of educational colonies. Who are they: educators, Trustees or only institutions of execution of punishments. Meanwhile, the correct understanding of the importance and role of the educational colony in the life of juvenile offenders in it, according to the author, will help to avoid a number of problems that objectively develop in institutions of this kind. From this point of view, the proposed topic is of interest not only for theoretical scientists, but for practitioners-employees of relevant institutions. It should be emphasized that there are no studies on this subject in the special literature. However, this circumstance can testify only about novelty of the given subject, but in any way about absence of the problem. It seems that the relevance and importance of a problem is not always measured by the number of studies devoted to it. Sometimes these its traits are manifest only under particularly careful consideration.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 827
Author(s):  
Omar Mologni ◽  
Eric D. T. Nance ◽  
C. Kevin Lyons ◽  
Luca Marchi ◽  
Stefano Grigolato ◽  
...  

Cable tensile forces in winch-assist harvesting have been investigated in order to assess the safety concerns of the technology. However, the literature is lacking, particularly in regards to the impact of winch design. In this study, a Summit Winch Assist tethering a feller-director on ground slopes up to 77% was monitored for four days. The cable tensile forces were simultaneously recorded at the harvesting and anchor machine at a frequency of 100 Hz. Cameras and GNSS devices enabled a time study of the operations and the recording of machine positions. Winch functionality and design were disclosed by the manufacturer and used for the interpretation of the results. The cable tensile forces reached 296 kN at the harvesting machine and 260 kN at the anchor machine. The slow negotiation of obstacles while moving downhill recorded the highest peaks, mainly due to threshold settings of the winch in the brake system activation. Lower but significant peaks were also recorded during stationary work tasks. The peaks, however, were limited to a few events and never exceeded the endurance limit of the cable. Overall, the study confirmed recent findings in cable tensile force analysis of active winch-assist operations and provided evidence of the underlaying mechanisms that contribute to cable tensile forces.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ryuya Namba

AbstractModerate deviation principles (MDPs) for random walks on covering graphs with groups of polynomial volume growth are discussed in a geometric point of view. They deal with any intermediate spatial scalings between those of laws of large numbers and those of central limit theorems. The corresponding rate functions are given by quadratic forms determined by the Albanese metric associated with the given random walks. We apply MDPs to establish laws of the iterated logarithm on the covering graphs by characterizing the set of all limit points of the normalized random walks.


2021 ◽  
Vol 4 ◽  
pp. 92-104
Author(s):  
Valentin Bahatskyi ◽  
◽  
Aleksey Bahatskyi ◽  

Currently, the measurement of electrical and non-electrical quantities is performed using analog-to-digital conversion channels, which consist of analog signal conditioning circuits and analog-to-digital converters (ADC) of electrical quantities into a digital code. The paper considers the case when the defining errors of the measurement and control channel are systematic errors of the ADC. The reliability of measurements is assessed by their errors, and the reliability of control - by the likelihood of correct operation of the control device. In our opinion, evaluating the reliability of such similar processes as measurement and control using different criteria seems illogical. The aim of the work is to study the effect of systematic errors of an analog-to-digital converter on the errors of parameter control depending on the type of conformity functions and the width of the control window, as well as the choice of the resolution of the ADC for various control tasks. The paper analyzes the transfer functions of measurement and control. It is shown that they are formed using step functions. It is proposed to use not a step function as a control transfer function, but other functions of conformity to the norm, for example, a linear function or functions of higher orders. In this case, the control result is assessed not according to the criterion of the probability of correct operation, but using the control error. Analyzed from the point of view of reconfiguring the errors of the line, parabolic and state parabolic functions of the norms for the development of changes windows in control. A recommendation has been given for the selection of functions for the conformity of standards and for the distribution of analog-to-digital conversions for industrial control enterprises.


Author(s):  
Mariana Abakarova

The article analyzes Lak proverbs with the religious cultural code. The research was based on the descriptive method, syntactical analysis, morphological analysis and cognitive analysis. The proverbs collected from 3 books of Lak proverbs were analyzed from the point of view of semantics, axiological connotations, syntax and morphology. Semantic analysis revealed 6 groups of lexemes: (1) denominations of people; (2) words related to religious pillars and rituals; (3) words related to holy scriptures, religious attributes and terms; (4) words denoting death and afterlife; (5) words denoting commendable religious acts and notions; (6) words denoting sin and punishment. In the course of the axiological analysis there have been defined proverbs with positive evaluation of a person and proverbs with negative characteristics of a person. Positive traits include honesty, piety, decency, erudition and diligence, while negative ones include insulation, indecency, hypocrisy and negligence in the religious worship. Syntactical analysis of the Lak proverbs has revealed the presence of adverbs of asyndetic structure within which there have been established adversative, concessive and comparative relations, as well as of proverbs with copulative and disjunctive conjunctions. Some of the proverbs are based on the principle of alogism. Morphological analysis of the proverbs has revealed the most frequent grammatical tense, the Present Affirmative Tense, which is formed by means of adding the affix -r to the present participle. The Present Affirmative Tense in the Lak language denotes an action as an attribute of the subject which explains the fact of usage of this tense in proverbs that summarize the social experience of the native speakers. Lak proverbs with the given code have not been researched earlier that makes this study relevant.


2019 ◽  
Vol 7 (1-2) ◽  
pp. 115-120
Author(s):  
Brigitta Zsótér ◽  
Ágnes Milojev

In our research work we aimed at carrying out an economical assessment of an investment and development of substantial volume. The examined project was completed at a pig-farm during which a new farrowing place and pig rearing building were built, as well as the renovation of the existing pig-farm. All of them were financed partly from the firm’s own source, partly from a non-repayable aid granted by the state, and finally from a credit granted by a commercial bank. The term of the credit is 10 years and the return of the investment expected by the investors is 8%, so we carried out our calculations according to these data. We examined the three possible ways of financing the investment from the economical point of view, as a result we proposed three hypotheses. Our hypotheses are: Hypothesis 1 (Case „A”): The investment will be financially recovered within the examined period of 10 years if it is financed from the firm’s own source, the state grant and the bank credit. Hypothesis 2 (Case „B”): The investment can be economically completed within the given period of time if the project meets the costs from the firm’s own source and the credit. Hypothesis 3 (Case „C”): The investment will be economically accomplished within the examined 10 years provided the firm finances the project from their own source and the state grant. In our calculations we used the net present value (NPV), the internal rate of return (IRR), the payback time (PB), the discounted payback time (DPB) and the profitability index (PI) as economy indicators. We carried out our calculations regarding 10 years to be able to compare the results since the term of the granted credit is 10 years, too.  


1970 ◽  
Vol 3 (1) ◽  
Author(s):  
A.K.M.N. Amin A.K.M.N. Amin ◽  
A.K. Sarder

Influence of the properties of work and tool materials on material removal rate (MRR), tool wear ratio (TWR), thickness of the recast layer, surface roughness and accuracy of machining in EDM process has been investigated. Copper brass, stainless steel, mild steel and grey cast irou have been used in various combinations as work and tool materials. From the experimental results it is found that MRR slows down with machining time. Apart from that it has been found that MRR and TWR are inversely proportional to the melting points of the work and tool materials respectively. Electrical conductivity of the tool material also has appreciable influence on tool wear ratio. Wear ratio was found to be minimum in the case of the copper electrode having maximum electrical conductivity.  It has been also observed that for all combinations of work and tool materials, a recast layer is formed on the machined surface. It has been observed that the micro cavities formed in the cases of lower melting point electrode materials like copper and brass having higher electrical conductivity are comparatively smaller in size (2-3 ?m) as compared to the sizes of the micro cavities (8-20 ?m) formed in the cases of high melting pointer electrodes having also lower electrical conductivity. Consequenty the machined surface roughness produced in the latter cases is higher.  It has been also observed that the debris concentration increases due to side sparking of the electrode. The tendency of debris concentration is the maximum at the middle of the tool-job interface resulting in high bottom surface inaccuracy, specially when high melting point work materials are machined with electrodes like brass having low melting point and relatively lower electrical conductivity. From the point of view of MRR, brass electrodes have been found to be the most suitable tool, but from the point of view of machining accuracy and surface finish copper electrodes were found to yield the best result for the given set of job materials. So it was concluded that brass electrodes should be recommended for rough machining and copper electrodes for finish machining of the given work materials.


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