Wyniki wyszukiwania - BazTech

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Identification of analytical dependencies of the operational characteristics of the workpiece clamping mechanisms with the rotary movement of the input link

Prydalnyi Borys, Sulym Heorhiy

Acta Mechanica et Automatica

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2021

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Vol. 15, no. 1

47--52

EN

The research is devoted to the problem of determining the efficiency of the workpiece fixing mechanism operation. Improving characteristics of workpiece fixing is one of the required conditions to increase the cutting modes, which may help to enhance the machining productivity. The study investigates the main characteristics and general features of a new structure of clamping mechanisms with electromechanical actuators for fixation of rotation bodies. The main advantages of using electromechanical clamping actuators with self-braking gear are presented. Two simplified dynamical models for the description of different stages of the clamping process are developed. The calculation scheme was formulated to find out how the mass-geometric parameters of mechanism elements should influence the main characteristics of the clamping mechanisms of this type.

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Comparative biomechanical characteristics of one-arm hang in climbing for beginners and qualified athletes

Kozin Sergii, Safronov Danil, Kozina Zhanneta, Kniaz Hanna, Proskurnia Olexsii, Prontenko Kostiantyn, Lahno Olena, Goncharenko Volodymyr, Kholodniy Alexandr

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 1

57--66

EN

The aim of the study was to identify the basic kinematic characteristics of the one-arm hang in climbing for beginners and qualified climbers. Material and methods: Technique of the one-arm hang in climbing among 20 leading climbers of the World and Ukraine and 20 beginner male amateur climbers was analyzed. A qualified athlete participated in the demonstration of various models of the one-arm hang performance. By means of Kinovea software 0.8.15, the kinematic characteristics of two models of the technique were analyzed (model 1 for beginner athletes, model 2 for qualified athletes). Results: The presence of significant differences ( p < 0.001) between beginners and qualified athletes in the magnitude of the angles between the shoulder and clavicle, between the spine and the vertical axis in the phase of fixation of the one-arm hang was revealed. The dynamics of the angle between the shoulder and clavicle from the moment of capture of the climbing hold to the phase of fixation of the hang was shown. A theoretical justification for the correct climbing technique regarding to the laws of mechanics and the laws of force interaction in kinematic chain was provided. Conclusions: Beginner athletes carry out the one-arm hang mainly due to the ligamentous apparatus of the joints of the shoulder girdle with minimal inclusion of muscles, which is dangerous by trauma to the ligaments of the shoulder joint. Skilled athletes perform the one-arm hang with trunk and leg muscles included, which reduces the strain from the ligamentous apparatus and lowers the possibility of injury to the ligaments of the shoulder joint.

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Dynamic Characteristic Analysis of the Needle Multi-linkage Mechanism in a Carpet Tufting Machine’s Driving System

Xu Y., Sun Z., Huang S., Sheng X., Chi X.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 3 (117)

103--109

EN

In a typical carpet tufting machine, kinematic and dynamic characteristics of the needle multi-linkage mechanism are the important factors affecting the quality of the tufting carpet. For providing a rational basis for mechanism design and vibration characteristic analysis, a mathematical model of the needle multi-linkage mechanism is constructed using the complex vector analysis method. On the basis of the model, kinematic characteristic curves and dynamic characteristic curves of the needle multi-linkage mechanism are analyzed by simulation methods. Finally experimental validation of the alternating load dynamic characteristics is performed on the needle multi-linkage mechanism in a typical carpet tufting machine. The results prove the theoretical analysis validity of the needle multi-linkage mechanism.

PL

W typowej maszynie wiążącej dywany charakterystyki kinematyczne i dynamiczne mechanizmu napędzającego układ igieł są bardzo ważnym czynnikiem określającym jakość wytwarzanych dywanów. Dla otrzymania racjonalnej podstawy dla projektowania mechanizmu i analizy charakterystyk wibracyjnych opracowano matematyczny model mechanizmu napędzającego igły. Przy opracowaniu modelu zastosowano metodę kompleksowej analizy wektorowej. Posłużyło to do otrzymania kinematycznych i dynamicznych krzywych przebiegu. Przebiegi te analizowano za pomocą metod symulacji. Następnie oceniono wyniki eksperymentalnie stosując typową maszynę do wytwarzania dywanów. Wyniki potwierdziły prawidłowość przyjętych teoretycznie zależności.

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Modelirovanie kinematičeskih harakteristik kulisnogo mehanizma s kačausimsâ cylindrom

Turanov H., Bondarenko A., Turanov S.

Zeszyty Naukowe Katedry Mechaniki Stosowanej / Politechnika Śląska

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1999

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z. 10

315-319

EN

In this article it is lead results definitions of transmissions gear functions and true meanings angular velocity of links double coulisse mechanism on basic vector algebra and calculus of derivatives.