Temat: HDD - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Summation equation tools for slide microbearing systems wear prognosis
Autorzy:: Wierzcholski, K.
Powiązania:: https://bibliotekanauki.pl/articles/242041.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: summation equation
wear prognosis
HDD micro-bearings
Opis:: Efficient functioning of slide micro-bearings systems especially HDD micro-bearing require to recognition and modulation of the proper values of the friction forces and wear during the exploitation time. Possibility of modulation and control of mentioned problem belong to the artificial intelligence of HDD micro-bearing. This paper presents the some applications of summation equations regard to the calculation prognosis of micro-bearing parameters such as friction forces, ,friction coefficients and wear .Summation equations are presented a new form of difference and recurrence equations where the unknown function occurs as the argument of the reciprocal unified operator of summation (UOS) Presented problem describes not continuous relations hence determines the mathematical and numerical solutions in discrete spaces. Properly in the case of continuous functions, the mentioned summation equations have the same meaning as integral equations. This paper will present the transformation method of summation equations to recurrent equations. Recurrent equations for discrete function correspond to differential equations for the continuous function. The Application of presented theory in this paper contains the numerical solutions referring the wear values of HDD bearing system in the indicated period of operating time.
Źródło:: Journal of KONES; 2011, 18, 2; 463-470
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Enhancement of memory capacity in HDD micro- bearing
Autorzy:: Wierzcholski, K.
Powiązania:: https://bibliotekanauki.pl/articles/243528.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: HDD slide micro- bearings
hyperbolic journal shapes
Opis:: The aim of the presented paper is presenting the shapes of HDD micro-bearing journal, which have influence on the enhancement of memory capacity. Moreover the asymmetrically grooved lateral surfaces of journal bearings generate the asymmetric pressure distribution, which leads to concentric rotation and eccentricity of a rotor. Most of the stiffness coefficient due to asymmetric grooves and hyperbolic shapes of lateral journal surfaces are bigger than those of the conventional cylindrical micro-bearings without grooves. The damping coefficients and friction torque due to asymmetric grooves and hyperbolic shapes of lateral journal surfaces are slightly bigger than those of the conventional cylindrical micro-bearings without grooves. The asymmetric grooves of hyperbolic micro journal bearings may have advantages in terms of small whirls radius and large dynamic coefficients occurring during the bearing exploitation. The idea of seeking of the slide micro-bearings with optimum of the capacity memory was implied from the author's investigation of human joints, which fulfil the role of intelligent bio-bearings. This paper investigates the dynamic behaviour of HDD micro-bearings with hyperbolic journal lateral shapes, by solving the proper Reynolds equation and the equation of a motion of a HDD spindle system. This paper presents the friction forces calculation in hydrodynamic HDD micro bearing lubrication with hyperbolic shapes of journals.
Źródło:: Journal of KONES; 2008, 15, 3; 555-560
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Solutions of recurrence and summation equations and their applications in slide bearing wear calculations
Autorzy:: Wierzcholski, K.
Powiązania:: https://bibliotekanauki.pl/articles/246728.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: wear prognosis
HDD micro-bearings
recurrence non-homogeneous equation
Opis:: The investigations under the paper include a derivation of a non-homogenous recurrence equation of the second and higher orders with variable coefficients, whose particular solutions, with the boundary conditions set and obtained from experimental measurements, will be the sequences of the wear value of the bearing in the successive years of operation. Owing to these investigations, it will be possible to predict for example the wear values of slide bearings. Moreover, this paper presents the some particular applications of recurrence equations with regard to the calculation prognosis of micro-bearing parameters such as friction forces, friction coefficients and wear. Recurrence equations are presented in a form of difference equations where the unknown functions occur as the main terms of the sequence of inquired values. In this paper, the properties of the particular values of recurrence equations are defined. Possibility of modulation and control of mentioned problem belong to the artificial intelligence of HDD microbearing. Presented problem describes not continuous relations hence determines the mathematical and numerical solutions in discrete spaces. Properly in the case of continuous functions, the mentioned recurrence equations have the same meaning as differential equations. Recurrent equations for discrete function correspond to differential equations for the continuous function. In final conclusions, the application of presented theory in this paper contains the numerical solutions referring the wear values of HDD bearing system in the indicated period of operating time.
Źródło:: Journal of KONES; 2012, 19, 2; 543-550
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: 3D hydrodynamic pressure in gap height direction for cylindrical bearing viscoelastic lubrication
Autorzy:: Wierzcholski, K.
Powiązania:: https://bibliotekanauki.pl/articles/246411.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: pressure changes in gap height direction
HDD micro-bearings
viscoelastic lubrication
Źródło:: Journal of KONES; 2013, 20, 1; 367-374
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Recurrent nets for tribology solutions
Autorzy:: Wierzcholski, K.
Powiązania:: https://bibliotekanauki.pl/articles/244153.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: pressure changes in gap height direction
HDD micro-bearings
viscoelastic lubrication
Opis:: The contemporary problems of numerical calculations ocurring in powertrain tribology and transport problems demand the more and more exactness for obtained results.Moreover in performed calculations very important is the convergence, stability and reliability of the gained numerical values. The main scientific topic of the presented paper concerns the method of the determination of the optimum net for numerical calculations of partial difference and recurrence equations. The abovementioned optimum difference and recurrence method is referring to the stability of obtained particular and general numerical solutions and assures the convergence process of obtained calculation values. The Unit Net Region (UNR) was assumed at first for Laplace Operator. The optimum of the nod geometry localization was examined at first for UNR. The optimization index is defined and derived for UNR to determine the most useful net among the various geometries of the nods localization during the difference methods performances of partial recurrence numerical calculations. In the next considerations had been proved the corollary, where taking into account the optimum UNR, we can create optimum nets for other numerous partial difference and recurrence equations in discrete spaces. For example the numerous calculation results of presented optimum net for recurrent calculations are applied for numerical solutions of a Reynolds partial recurrence equation with variable coefficients in curvilinear orthogonal coordinates for curvilinear boundary conditions, and for other numerical problems occurring in applied and hydrodynamics.
Źródło:: Journal of KONES; 2013, 20, 2; 401-408
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Surface topography of operated slide journal micro - bearings used in HDD
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/242978.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: atomic force microscope
surface topography
microgrooves
herringbone grooves
micro bearing in HDD
Opis:: In this paper author present results of measurements of slide journal micro-bearings surface topography measured with an atomic force microscope (AFM). The results of measurements of surface topography were presented in the form of surface topography maps, three-dimensional graphs and some examples of selected cross-sections of investigated surface in the form of profile graphs. Measurements of surface topography were made for journals and sleeves of slide journal micro-bearings from personal computers' hard disc drives, with the Atomic Force Microscope NT-206 produced in MTM in Minsk, Republic of Belarus. In this research author used two identical sets of micro-bearings from 2.5" HDD Samsung HM160HI 5400rpm and 3.5" HDD Seagate Barracuda 7200.10 ST380815AS 7200 rpm hard disc drives. First set of those four microbearings worked for a year at rated RPM continuously (i.e. 24 hours a day). Second set of the same micro-bearings also worked for a year at rated RPM, but in intermittent mode (i.e. 15 minutes on, 15 minutes off). The values of profile roughness parameters Ra and Rq and the distance between maximum peak height and maximum valley depth are presented as well. The application SurfaceXplorer registered trademark was used for processing and visualization of the data obtained from AFM NT-206, which besides from generating 2D, 3D and profile diagrams, was used to calculate and draw graph of height distribution. Surface topography of investigated bearings sleeves was also measured using Hommeltester T8000-R60 profilometer. Those measurements give information about micro-grooves dimensions and location. On the surfaces of studied micro-bearings, some micro-grooves can be found in form of herringbone, with depth about 1.5..m and width 150..m. Received information about micro-grooves geometry will allow developing proper theory of hydrodynamic lubrication for micro-bearings with micro-grooves.
Źródło:: Journal of KONES; 2012, 19, 4; 449-456
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Operating parameters of slide micro – bearings with consideration of oil temperature changes and micro - grooves on sleeve surface
Autorzy:: Miszczak, A.
Powiązania:: https://bibliotekanauki.pl/articles/247490.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: HDD micro-bearings
micro-grooved surfaces
oil viscosity changes in gap height
hydrodynamic pressure
friction forces
load carrying capacity
Opis:: In this paper author presents results of numerical calculations of hydrodynamic pressure distribution in bearing gap, load-carrying capacity, friction force and friction coefficient of slide micro-bearing considering the influence of lubricating oil temperature changes and also taking into account the influence of micro-grooves, which occur on sleeve internal surface. The micro-grooves on that surface are in longitudinal direction. The equation, which describes a bearing gap with micro-grooves on sleeve surface, was adopted from prof. K Wierzcholski's investigations. In very thin gap height of cylindrical micro-bearings, large gradients of temperature can be observed. This causes significant changes of oil dynamic viscosity in the gap height direction. According to this, oil flow velocity, friction forces, and a hydrodynamic pressure during the micro-bearing operation are changing. Up to now the influence of temperature on oil viscosity changes and due to this, on hydrodynamic pressure and on load carrying capacity in cylindrical micro-bearing gap in numerical way were not considered yet. The numerical calculations were performed with the use of Mathcad 14. The finite differences method and own computational procedures were implemented. The calculations were begun by solving the Reynolds' equation, assuming, that the dynamic viscosity is constant. After calculating the hydrodynamic pressure distribution, the temperature distribution in lubricating oil was determined. The obtained function of temperature was used to describe the viscosity changes with temperature. Next step involved determining the hydrodynamic pressure distribution taking into account the viscosity dependence on temperature, and then new distribution of temperature and again new values of viscosity were calculated. Calculations were repeated until assumed convergence and accuracy were reached. The friction force depends on pressure gradient and rotational motion of bearing journal. Part of friction force, which resulting from the pressure gradient, is determined for the area, where the oil film occurs, i.e. from omega p to omega k. Part of friction force, which is related to journal motion, is determined for full wrap angle, i.e. from 0 to 2 pi. The results were presented in the form of graphs, for eccentricity ratio gamma from 0.1 to 0.9, for dimensionless length of the bearing L1=1/4. In numerical calculations were used the theoretical considerations and solutions presented in papers of K. Wierzcholski and A. Miszczak.
Źródło:: Journal of KONES; 2012, 19, 2; 329-336
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "HDD" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język