Wyniki wyszukiwania - BazTech

1

Static condensation in modeling roller guides with preload

Dunaj Paweł, Berczyński Stefan, Pawełko Piotr, Grządziel Zenon, Chodźko Marcin

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 4

1072--1082

EN

This article presents the methodology for modeling the stiffness of a machine tool load-bearing system using the finite element method. A new, simplified model of stiffness of the linear guide with a preload based on equivalent contact model was proposed. An equivalent contract model was developed where the ball was replaced with four rod elements of equivalent stiffness, interconnecting the opposite ends of the face of cuboidal finite ele- ments. To shorten the computation time and facilitate modeling reduction and substructur-ing methods was used. The accuracy of the proposed model was compared with experimental results. In addition, the computation times were evaluated by comparing the simplified model with the full model and other equivalent models. Then, the model was used to determine the stiffness of the machine load-bearing system on the example of a machining table using the aforementioned methods and the obtained results were com-pared in terms of accuracy (less than 1% difference in maximum displacement value) and computation time with the classic approach (up to 97% in time reduction). This paper demonstrated the validity of the proposed model, allowing accurate and fast determination of the stiffness of machine tool load-bearing system.

2

Modeling roller guides with preload

Pawełko P., Berczyński S., Grządziel Z.

Archives of Civil and Mechanical Engineering

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2014

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Vol. 14, no. 4

691--699

EN

This article presents the methodological basis and methods of modeling roller guides, which consist of a carriage and profiled guide rail with introduced preload. It also discusses modeling methods with various degrees of simplification and selected results of numerical analyses concerning the examined guides. The applied methods of modeling are then assessed in terms of their effectiveness.

3

An analysis of normal contact deformations in the basic model of roller guideway of machine tool

Grudziński P.

Advances in Manufacturing Science and Technology

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2009

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Vol. 33, nr 3

27-40

EN

This paper analyses the basic model of a roller guideway of a machine tool. It shows that the normal contact deformations in such a model, obtained by the empirical formula given in the manufacturer's catalogue of these guideways, and also by the Hertzian theory, are far smaller than the ones obtained experimentally for such a system. The main reason for these discrepancies seems to be the fact that the basic model and calculation formulae did not take into account the influence of surface roughness of the raceways and roller. It is demonstrated that by using the FE system ANSYS and taking into account the contact stiffness of surfaces roughness, it is possible to get calculation results that are in good agreement with the experimental results.

PL

W pracy przedstawiono analizę modelu bazowego rolkowej prowadnicy obrabiarki. Wykazano, że odkształcenia kontaktowe normalne w takim modelu określone są na podstawie zależności empirycznej, ustalone przez producenta tych prowadnic, a także według teorii Hertza, mają znacznie mniejsze wartości od wyznaczonych doświadczalnie dla takiego układu. Stwierdzono, że główną przyczyną różnicy tych wartości jest brak uwzględnienia w przyjętym modelu i obliczeniach wpływu chropowatości powierzchni bieżni i rolki. Wykazano, że zastosowanie do obliczeń programu MES ANSYS i uwzględnienie sztywności kontaktowej chropowatych powierzchni umożliwia uzyskanie wyników w dobrej zgodności z wynikami badań doświadczalnych.