Wyniki wyszukiwania - BazTech

1

Feasibility study on the submerged floating tunnel in Qiongzhou Strait, China

Jiang B., Liang B., Wu S.

Polish Maritime Research

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2018

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S 2

4--11

EN

Abstract: Currently, one of the challenging tasks for Chinese engineering community is to construct a water-way crossing of Qiongzhou Strait in the south of China. This project has also gained significant attention from researchers in academia. The study presented herein is centered on providing a feasible solution for ac-complishing the above mentioned task. Initially, different alternatives as the best location, judged on the basis of the environmental constraints, are studied. Then the comparison between various structural solutions such as suspension bridge, submarine tunnel and SFT is presented. Among these solutions, SFT appears to be a very suitable alternative for Qiongzhou Strait waterway crossing due to distinctive advantages, like shorter distance, lower cost, less impact on environment and navigation, etc. Based on the appropriate conception for cross sections, support systems, materials, joints and connection schemes, a numerical model is developed by means of the FEM software ANSYS/Fluent. It is then analyzed under the influence of different environmental loading conditions, varying the wave heights and lengths, current velocities and water depths, which are typical in Qiongzhou Strait. The numerical results reveal that the proposed SFT solution performs safely even under extreme weather conditions.

2

Badania przekładni falowej klasy Harmonic Drive

Kosmol J., Mnich M.

Prace Naukowe Katedry Budowy Maszyn / Politechnika Śląska

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2013

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nr 2

49--62

EN

The paper presents construction and analysis of wave drives based on Harmonic Drive type example. The main exploitation parameters were defined from the point of view of their application, first of all, in mechatronic devices and machines, where requirements of positioning are very high. Examples of test results of such parameters of professional wave drive are shown. It was confirmed, basing on obtained results of investigation, that angle aceuracy of positioning about 0,020 [°], that means 1,2′, is available. Such precision may be obtained for a very simple stepper motor wit open loop control and this precision can be satisfying in many practical applications.

PL

W artykule przedstawiono budowę i działanie przekładni falowych na przykładzie przekładni Harmonie Drive. Zdefiniowano parametry eksploatacyjne takiej przekładni, które decydują o jej przydatności, zwłaszcza w urządzeniach i maszynach o wysokich wymaganiach odnośnie do dokładności pozycjonowania. W artykule zamieszczono także przykładowe wyniki badań tych parametrów dla konkretnej przekładni falowej. Stwierdzono, na przykładzie przeprowadzonych badań, że do osiągnięcia jest dokładność pozycjonowania kątowego na poziomie 0,020 [°], co odpowiada ok. 1,2′. Tę dokładność uzyskuje się dla prostego sterowania otwartego z silnikiem skokowym. Taka wartość dla wielu praktycznych zastosowań jest całkowicie wystarczająca

3

Analysis of stress state of toothed ring of flexspline by means the BEM

Folęga P.

Archives of Materials Science and Engineering

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2013

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Vol. 59, nr 1

40--45

EN

Purpose: The paper presents an analysis of the influence of design features of the flexspline in a harmonic drive, such as the relative radial deformation, the relative coating thickness and the design features of the basic rack tooth profile, on stress values in the bottom lands of a toothed ring. Design/methodology/approach: In numerical calculations, the software developed at the Faculty of Transport of the Silesian University of Technology was used. The program automatically generates a profile of the flexspline and a boundary elements mesh on the grounds of the flexspline and working tool assigned parameters. In the analysis of the state of stress, the boundary element method (BEM) was applied. Findings: A decreased value of the curve radius of the head of the basic rack tooth profile results in a change in the width of the tooth bottom land, shortening of the transition curve in the tooth base and a reduction of the tooth thickness at its base, which in turn leads to increased values of stress. Yet, the influence of the relative curve radius of the head of the basic rack tooth profile on the stress value is insignificant. The increase of the torque and relative coating thickness for different value of the curve radius of the head of the basic rack tooth profile cause an increase of stress in the bottom lands of the toothed ring. Research limitations/implications: The paper presents strength calculations for the teeth in toothed ring of a flexspline of a double harmonic drive by means of boundary elements method (BEM). The results of numerical calculations correspond in terms of their quality to the results presented in the literature, which were calculated by finite element method (FEM). Originality/value: In the analysis of the state of stress of toothed ring of flexspline, the boundary element method (BEM) was applied.

4

Selected aspects of methodology of a CAPP system design

Grabowik C.

Journal of Machine Engineering

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2011

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Vol. 11, No. 1-2

78--86

EN

In this paper the selected aspects of the methodology of a CAPP system design are presented. The special emphasis was put on problems of design features identification and method of design representation. Based on the carried out design features identification process the open structure of design features was worked out. This open structure was the base in the process of elaboration of the CAD application which was thought as a source of design data for a CAPP system. Moreover on the basis of the open structure of design features the formal FMCAD model was elaborated. This formal model is use for design representation purpose. Based on this model the AXI-CAD application was elaborated. The purpose of this application is to model a design of rotational products. The paper is finished with a short example of practical application of AXI-CAD module and some further direction of software development.

5

The influence of the constructional features of a ring-ball mill on its efficiency.

Mroczek K., Chmielniak T.

Archive of Mechanical Engineering

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2006

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Vol. LIII, nr 1

89-116

EN

The empirical-analytic model of milling in a ring-ball mill has been presented. It concerns the interaction of the basic design features of the grinding unit (geometry, rate of grinding and thrust of the balls) on the maximum efficiency of the mill. The production of pulverized coal was expressed by the product of the flux of material drawn in by the balls and the so-called "grinding effect of the balls" (defined by the increase of the mass fraction of dust in its flux). The kinematic quantities (among others, the flux of loose material drawn in by the balls) have been calculated on the basis of a simple analytical description of the flow of particles and some parametrical assumptions. The grinding properties of coal have been determined making use of laboratory tests of its cruising by the rollers. Some verifications of the grinding model on the experimental test stand with a ring-ball mill have been presented. The test stand is installed at the Institute of Power Engineering and Turbomachinery of the Silesian University of Technology.

PL

Przedstawiono empiryczno-analityczny model mielenia w młynie pierścieniowo-kulowym. Ujmuje on oddziaływanie podstawowych cech konstrukcyjnych takich jak: geometria zespołu, prędkość kątowa i nacisk elementów mielących,. Wydajność młyna wyrażono iloczynem strumienia węgla wciąganego przez kule i tzw. efektu mielenia kul (jednostkowego przyrostu frakcji pyłowej w tym strumieniu). Wielkości kinematyczne (w tym strumień węgla wciąganego przez kule) wyznaczono na podstawie analitycznego opisu ruchu materiału sypkiego i pewnych założeń parametrycznych. Właściwości węgla względem rozdrabniania określono na podstawie laboratoryjnych badań jego miażdżenia pod elementami walcowymi. Przedstawiono wybrane weryfikacje modelu w doświadczalnym młynie pierścieniowo-kulowym zainstalowanym w IMiUE Pol. Śl.

6

The choice of design features for ring-ball mills.

Mroczek K., Chmielniak T.

Archive of Mechanical Engineering

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2005

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Vol. LII, nr 2

191-205

EN

The paper discusses a way of choosing the design features (geometry, the rate of grinding and thrust) of ring-ball mills. Various methods of calculating the optimal rate of grinding have been compared. Basing on experimental investigations on the pilot-plant and industrial scale, the influence of the angular velocity and the thrust on the mill have been verified, and the independence between the rate of grinding and the thrust of the grinding elements have been explained.

PL

W artykule przedstawiono sposób doboru cech konstrukcyjnych (geometrii, prędkości mielenia, nacisku) młynów pierścieniowo-kołowych. Porównano różne metody obliczeń optymalnej prędkości mielenia. Na podstawie badań eksperymentalnych, pilotowych i przemysłowych, zweryfikowano wpływ prędkości kątowej i docisku kul na wydajność młyna. Wyjaśniono wpółzależność prędkości mielenia - nacisk elementów mielących. Zalecono zmniejszenie prędkości obrotowej zespołu napędowego dla poprawy cech eksploatacyjnych młyna.

7

Problemy z akumulatorami kwasowymi

Świątek M.

Wiadomości Elektrotechniczne

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2002

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R. LXX, nr 7-8

290-296

PL

Przedstawiono definicje pojęć dotyczących akumulatorów. Omówiono budowę i zasady działania akumulatorów kwasowo-ołowiowych oraz czynniki wpływające na ich żywotność.

EN

Definitions of the concepts concerning the accumulators. Design features and operation principles of lead-acid accumulators; factors influencing their life.

8

The constructional possibilities of noise control in toothed-belt drives of the shredder.

Flizikowski Józef, Macko Marek

Archive of Mechanical Engineering

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1998

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vol. XLV, nr 4

293-304

EN

In the papaer expressions are given for the main sources of noise emitted while milling and influence of selected constructional features in power transmission and functional system on noise level. The object of investigation was multiple disc shredder. Based on literature and aur own measurement results we distinguished constructional features which have decisive influence on noise emission in the toothed-belt drive (as a power transmission system) and multiple disc cutter (as a functional system). On the basic of our studies, it has been observed that profile form of the belt's tooth (T, AT, ATP, THP belt profile's studies) has a great influence on the noise emitted across the most of the range of rotational speed measured.

PL

W pracy zaprezentowano próbę optymalizacji cech konstrukcyjnych układu funkcjonalnego i napędowego pod kątem minimalizacji hałasu podczas rozdrabniania tworzyw sztucznych. Analizie poddano układ napędowy rozdabniacza wielotarczowego działającego na zasadzie quasi-ścinania materiałów kawałkowych, w którym wyodrębniono układ funkcjonalny oraz układ napędowy. Szczególną uwagę zwrócono na wpływ cech konstrukcyjnych przekładni pasowo-zębatej typu T, AT, ATP, THP na hałas podczas biegu z różną prędkością obrotową wału wejściowego.