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Wyszukujesz frazę "hydrodynamic bearing" wg kryterium: Wszystkie pola


Tytuł:
CFD analysis of non-Newtonian and non-isothermal lubrication of hydrodynamic conical bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/243876.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical bearing
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
non-isothermal flow
pressure distribution
Opis:
In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of non-isothermal oil flow in a bearing lubrication gap and also with assumption, that oil has non- Newtonian properties. The determination of hydrodynamic pressure distribution in bearing gap was carried out by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were performed for bearings without misalignment, i.e. where the cone generating line of bearing shaft is parallel to the cone generating line of bearing sleeve. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that the flow in the bearing lubrication gap is isothermal. Some other simplifying assumptions are: a steady-state operating conditions of a bearing, incompressible flow of lubricating oil, no slip on bearing surfaces, pressure on the side surfaces of bearing gap is equal to atmospheric pressure. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:
Journal of KONES; 2014, 21, 4; 49-56
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized Newtonian fluids as lubricants in the hydrodynamic conical bearings : a CFD analysis
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/242462.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic conical bearing
generalized Newtonian fluid
CFD
non-Newtonian oil
pressure distribution
dynamic viscosity
ferro-oil
Opis:
Additives, ageing or wear and impurities can cause, that relationship between shear stress and shear rate in a lubricating oil is or becomes non-linear, and due to this, a significant change in the values of operating parameters of slide hydrodynamic bearings may occur. It is important to take into account such dependence during design and simulations of slide bearings. The calculations, which consider the non-linear properties of the lubricating oil, can be carried out by adopting the generalized Newtonian fluid models. This paper shows the result of CFD simulation of slide conical bearings hydrodynamic lubrication, assuming that the lubricating oil behaves as a generalized Newtonian fluid. The hydrodynamic pressure distributions, load carrying capacities and friction torques were calculated for bearings lubricated with different types of generalized Newtonian fluids and the obtained data were compared. In the study, the following models of fluids were adopted: the Power-law fluid (Ostwald-de Waele), the Cross fluid and the Carreau fluid. The coefficients of mentioned relationships were determined by fitting the curves described by each model to the experimental data using the least squares approximation method. The calculations of hydrodynamic pressure distributions, load carrying capacities and friction torques were carried out using the commercial CFD software Ansys Fluent from the Ansys Workbench 2 platform.
Źródło:
Journal of KONES; 2016, 23, 2; 89-95
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of effect of misalignment plane position on hydrodynamic lubrication of slide conical bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/246851.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
slide bearing
hydrodynamic lubrication
conical bearing
misalignment
CFD
pressure distribution
Opis:
The numerical calculations of the hydrodynamic lubrication of slide bearings can be carried out by modelling the oil flow for a given value of height of bearing lubrication gap. On the basis of the assumed height of the lubrication gap, the values of hydrodynamic pressures, load carrying capacities, friction forces, temperatures, can be determined. The bearing lubrication gap height can be influenced by many effects, e.g. misalignment between the shaft axis and the axis of the sleeve, vibrations, varying load, change in the viscosity value of lubricating oil caused by changes in temperature, pressure, shear rate or by oil ageing, wear of journal and sleeve surfaces. This article presents the results of numerical simulations concerning the influence of the misalignment between the axis of shaft and the axis of sleeve of the sliding conical bearing on its hydrodynamic lubrication, by taking into account the position of the plane in which the misalignment occurs. In this study, there was defined an angle between the plane in which the misalignment occurs and the plane in which lies the line of centres of corresponding bearing without misalignment. In this research, to investigate the impact of the position of the plane in which the misalignment occurs, the CFD software, designed to solve general flow phenomena, was used. It was assumed, that the bearings operate in a steady state conditions, the flow in the bearing lubrication gap is laminar and non-isothermal. A lubricating oil has shear properties as the Ostwald-de Waele fluid.
Źródło:
Journal of KONES; 2017, 24, 2; 65-72
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of influence of axial position of shaft on hydrodynamic lubrication of slide conical bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/241575.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic lubrication
conical bearing
slide bearing
radial clearance
CFD
Opis:
During the operation of a slide bearing, the position of its shaft or sleeve varies due to many factors, such as vibrations, load changes, changes in the lubricating viscosity. The vibrations or varying load can cause, that the position of the bearing shaft, measured along its axis of rotation, changes. This is particularly important for sliding bearing with conical geometry. Due to the geometry of this kind of bearing, i.e. where the radius of this bearing (of the shaft and sleeve) has not a constant value, as in the case of a journal bearing, it is more difficult to obtain proper values and describe its hydrodynamic lubrication. This article shows the results of hydrodynamic lubrication of the slide conical bearing, for which the changes in the position of the bearing shaft in the longitudinal direction, i.e. along its axis of rotation, were taken into account. The commercial CFD software, designed for solving general for flow phenomena problems, was used in the simulations. This article shows the results of simulations, assuming that the lubricating oil behaves as a generalized Newtonian fluid. The hydrodynamic pressure distributions, load carrying capacities and friction torques were calculated for the concerned bearing. The aim of this work is to show how the operating parameters of the slide conical bearing can be influenced, by only changes of the position of the shaft along the axis of its rotation.
Źródło:
Journal of KONES; 2017, 24, 3; 37-44
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of hydrodynamic lubrication of slide conical bearing with consideration of the bearing shaft and sleeve surface roughness
Autorzy:
Czaban, A
Powiązania:
https://bibliotekanauki.pl/articles/246600.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical bearing
surface roughness
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
pressure distribution
sand-grain roughness
Opis:
In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of the effect of the bearing shaft and sleeve surface roughness. The oil flow in a bearing lubrication gap largely depend on the condition of the cooperating surfaces of a bearing. Surface irregularities are formed already at the manufacturing process and furthermore the quality of the surface may change during operation of a bearing. In this work, as a parameter describing surface condition, the Ks roughness height parameter was taken (i.e. sand-grain roughness height). The hydrodynamic pressure distribution in lubrication gaps of investigated bearings were calculated by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were conducted for bearings without misalignment. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that bearings have smooth surfaces and there is no slip on surfaces. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:
Journal of KONES; 2014, 21, 3; 35-40
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulations of the influence of the heat flux at the shaft surface of the conical slide bearing on its hydrodynamic lubrication and operating parameters
Autorzy:
Czaban, Adam
Miszczak, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/243495.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic lubrication
slide bearing
conical bearing
heat conduction
pressure distribution
viscosity
Opis:
The aim of this work is to investigate, how in the adopted model of hydrodynamic lubrication of a conical slide bearing, the change of the heat flux value at the bearing shaft, affects bearing operating parameters. In this research, the authors use, the known from the literature, Reynolds type equation, describing the stationary hydrodynamic lubrication process of a conical slide bearing. The analytical, solutions, that determine the components of the lubricating oil velocity vector and the equation (analytical solution of energy equation) determining the threedimensional temperature distribution in the lubrication gap, was also adopted from previous works. In order to obtain numerical solutions, the Newton’s method was used, and the derivatives in the Reynolds type equation were approximated by the finite differences. An application of the method of subsequent approximations allowed considering the influence of temperature, pressure and shearing rate on the viscosity of lubricating oil. The considerations were performed by adopting the Reynolds condition of the hydrodynamic oil film. It was tested, how the assumed value of the heat flux on the bearing shaft surface affects the values of the obtained operating parameters, i.e. the transverse and longitudinal component of the load carrying capacity, friction force and coefficient of friction.
Źródło:
Journal of KONES; 2019, 26, 4; 29-37
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of the impact of a cone opening angle parameter on the hydrodynamic lubrication of the conical slide bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/242697.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic lubrication
slide bearing
conical bearing
cone opening angle
CFD
pressure distribution
Opis:
The height of the oil lubrication gap is the primary quantity that determines in simulations the operating parameters of a hydrodynamic slide bearing. It is influenced by multiple effects, such as vibrations during operation, varying load, misalignment between the shaft axis and the axis of the bearing sleeve, the roughness of the journal and sleeve surfaces, change in the viscosity value of lubricating oil caused by changes in temperature, pressure, shear rate or by oil ageing, wear of journal and sleeve surfaces etc. It is important to take into account such effects considering hydrodynamic lubrication simulations and design of the slide bearings. The one of the factors influencing the height of the oil lubrication gap of the conical slide bearing is the difference between the opening angle of the cone of bearing shaft and opening angle of the cone of bearing sleeve. The aim of this work is to investigate the impact of the difference between the values of these angles on the hydrodynamic lubrication of the conical slide bearing. The commercial CFD software Ansys Fluent, from the Ansys Workbench 2 platform, was used to determine the hydrodynamic pressure distributions, load carrying capacities and friction torques of the simulated bearings. It was assumed, that the bearings operate in a steady state conditions, the flow in the bearing lubrication gap is laminar and non-isothermal, there is no misalignment between the axis of bearing journal and axis of bearing sleeve, the surfaces of the journal and sleeve are smooth and lubricating oil acts as a liquid described by the Ostwald-de Waele power law model.
Źródło:
Journal of KONES; 2016, 23, 3; 71-77
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of influence of bearing material thermal conductivity coefficient on hydrodynamic lubrication of a conical slide bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/246592.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
slide bearing
hydrodynamic lubrication
conical bearing
heat conduction
pressure distribution
Opis:
One of the main parameters affecting the hydrodynamic lubrication of slide bearings is the viscosity of lubricating oil. Many studies show, that significant changes in the viscosity of oil occur along with changes in its temperature. The influence on the temperature distribution in the lubrication gap of the slide bearing have a variety of factors, and one of them is the amount of heat exchanged between the lubricant and the environment. The temperature of the lubricating oil of operating bearing is usually higher than the ambient temperature. In addition to the convection, which occurs during the flow (heat exchange related to the oil supply and discharge system) some amount of heat is transferred to the bearing sleeve material (and also to the bearing shaft), and then it is conducted to sleeve outer surface. The amount of heat transferred through the bearing sleeve is mainly dependent on the difference of temperatures between inner and outer sleeve surfaces and also depend on the heat conduction coefficient of sleeve material. This article presents the results of modelling of the influence of amount of heat conducted through the bearing material, on the hydrodynamic lubrication of a conical slide bearing. The study concerned various values of the heat conduction coefficient of the bearing material to investigate its influence on the temperature values of lubricating oil, and thus, on its viscosity, on the distribution of hydrodynamic pressure and on the calculated values of bearing load carrying capacities and friction forces.
Źródło:
Journal of KONES; 2018, 25, 2; 89-96
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Operating parameters of a slide bearing with parabolic-shaped slide surfaces with consideration of the stochastic changes in the lubrication gap height
Autorzy:
Miszczak, Andrzej
Wierzcholski, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/244155.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic lubrication
analytical stochastic principles
solutions
apparent viscosity
numerical calculation
load carrying capacity
friction force
Opis:
In this article, the authors present the equations of the hydrodynamic theory for a slide bearing with parabolicshaped slide surfaces. The lubricating oil is characterized by non-Newtonian properties, i.e. an oil for which, apart from the classic oil viscosity dependence on pressure and temperature, also an effect of the shear rate is taken into account. The first order constitutive equation was adopted for considerations, where the apparent viscosity was described by the Cross equation. The analytical solution uses stochastic equations of the momentum conservation law, the stream continuity and the energy conservation law. The solution takes into account the expected values of the hydrodynamic pressure EX[p(ϕ,ζ)], of the temperature EX[T(ϕ,y,ζ)], of the velocity value of lubricating oil EX[vi(ϕ,y,ζ)], of the viscosity of lubricating oil EX[ηT(ϕ,y,ζ)] and of the lubrication gap height EX[εT(ϕ,ζ)]. It was assumed, that the oil is incompressible and the changes in its density and thermal conductivity were omitted. A flow of lubricating oil was laminar and non-isothermal. The research concerned the parabolic slide bearing of finite length, with a smooth sleeve surface, with a full wrap angle. The aim of this work is to derive the stochastic equations, that allow to determine the temperature distribution, hydrodynamic pressure distribution, velocity vector components, load carrying capacity, friction force and friction coefficient, in the parabolic sliding bearing, lubricated with nonNewton (Cross) oil, including the stochastic changes in the lubrication gap height. The paper presents the results of analytical and numerical calculation of flow and operating parameters in parabolic sliding bearings, taking into account the stochastic height of the lubrication gap. Numerical calculations were performed using the method of successive approximations and finite differences, with own calculation procedures and the Mathcad 15 software.
Źródło:
Journal of KONES; 2019, 26, 4; 171-178
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure and velocity distribution in slide journal bearing lubricated micropolar oil
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/247206.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
micropolar lubrication
journal bearing
hydrodynamic pressure
velocity
velocity of microrotation
Opis:
Present paper shows the results of numerical solution Reynolds equation for laminar, steady oil flow in slide bearing gap. Lubrication oil is fluid with micropolar structure. Materials engineering and tribology development helps to introduce oils with the compound structure (together with micropolar structure) as a lubricating factors. Properties of oil lubrication as of liquid with micropolar structure in comparison with Newtonian liquid, characterized are in respect of dynamic viscosity additionally dynamic couple viscosity and three dynamic rotation viscosity. Under regard of build structural element of liquid characterized is additionally microinertia coefficient. In modelling properties and structures of micropolar liquid one introduced dimensionless parameter with in terminal chance conversion micropolar liquid to Newtonian liquid. The results shown on diagrams of hydrodynamic pressure, velocity and velocity of microrotation distribution in dimensionless form in dependence on coupling number N2 and characteristic dimensionless length of micropolar fluid A1. Differences were showed on graphs in the schedule of the circumferential velocity oils after the height of the gap in the flow of the micropolar and Newtonian liquid. In presented flow, the influence of lubricating fluid inertia force and the external elementary body force field were omitted. Presented calculations are limited to isothermal models of bearing with infinite length.
Źródło:
Journal of KONES; 2011, 18, 4; 213-220
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure and capacity force in slide journal plane bearing lubricated oil with micropolar structure
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/950089.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
micropolar lubrication
journal plane bearing
hydrodynamic pressure
Opis:
Present paper shows the results of numerical solution Reynolds equation for laminar, steady oil flow in slide plane bearing gap. Lubrication oil is fluid with micropolar structure. Properties of oil lubrication as of liquid with micropolar structure in comparison with Newtonian liquid, characterized are in respect of dynamic viscosity additionally dynamic couple viscosity and three dynamic rotation viscosity. Under regard of build structural element of liquid characterized is additionally microinertia coefficient. In modelling properties and structures of micropolar liquid one introduced dimensionless parameter with in terminal chance conversion micropolar liquid to Newtonian liquid. The results shown on diagrams of hydrodynamic pressure in dimensionless form in dependence on coupling number N and characteristic dimensionless length of micropolar fluid A1. Presented calculations are limited to isothermal models of bearing with inflnite breadth. Especially, geometry schema of the slide Journal plane bearing gap, the dimensionless pressure distributions p1 in dependence on coupling number N2, the dimensionless pressure distributions p1 in dependence on characteristic dimensionless length of micropolar fluid, the dimensionless maximal pressure p1m in dependence on coupling number N, gap convergence coefficient are presented in the paper.
Źródło:
Journal of KONES; 2009, 16, 2; 247-253
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distributions of hydrodynamic pressure in the gap of slide journal bearing lubricated with ferro-oil
Autorzy:
Frycz, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/247084.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
temperature distribution
journal slide bearing
ferro-oil
Opis:
This research work is part of a broader comprehensive issue, which is the analysis of flow and operating parameters of journal slide bearings lubricated with ferro-oil. In this article, the author presents only the main assumptions and essential transformations of the analytical and numerical model for determining the pressure distributions in the gap of a slide journal bearing lubricated with ferro-oil. It is cardinal that the rheological and magnetic values of ferro-oil parameters adopted in numerical calculations are based on the results of actual values obtained in the author’s earlier research work. There are presented the pressure distributions by abovementioned method in the article for cases of bearings lubricated with ferro-oils with different concentration of magnetic particles. The obtained results are shown in the form of a set of four complementary characteristics of the dimensionless pressure distributions. First and main of them are the calculations for classical Newtonian lubrication but they take into account the influence of the magnetic field on the distributions. The next of the presented characteristics are so-called "corrections" of pressure distribution values, taking into account as follows: effects of changes in ferro-oil viscosity related to temperature changes, impacts of ferro-oil viscosity changes related to pressure changes and the effect of non-oil properties of the lubricant. The article includes a qualitative and quantitative analysis of the obtained results as well as observations and conclusions are presented in it.
Źródło:
Journal of KONES; 2019, 26, 4; 53-61
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pressure and velocity distribution in slide journal plane bearing lubricated with micropolar oil
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/246956.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
micropolar lubrication
journal plane bearing
hydrodynamic pressure
velocity
velocity of microrotation
Opis:
Present paper shows the results of numerical solution Reynolds equation for laminar, steady oil flow in slide plane bearing gap. Lubrication oil is fluid with micropolar structure. Materials engineering and tribology development helps to introduce oils with the compound structure (together with micropolar structure) as a lubricating factors. Properties of oil lubrication as of liquid with micropolar structure in comparison with Newtonian liquid, characterized are in respect of dynamic viscosity additionally dynamic couple viscosity and three dynamic rotation viscosity. Under regard of build structural element of liquid characterized is additionally microinertia coefficient. In modelling properties and structures of micropolar liquid one introduced dimensionless parameter with in terminal chance conversion micropolar liquid to Newtonian liquid. The results shown on diagrams of hydrodynamic pressure, velocity and velocity of microrotation distribution in dimensionless form in dependence on coupling number N2 and characteristic dimensionless length of micropolar fluid Lambda 1. Differences were showed on graphs in the schedule of the longitudinal velocity oils after the height of the gap in the flow of the micropolar and Newtonian liquid. In presented flow, the influence of lubricating fluid inertia force and the external elementary body force field were omitted. Presented calculations are limited to isothermal models of bearing with infinite breadth.
Źródło:
Journal of KONES; 2010, 17, 2; 249-256
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of the microgrooves on the hydrodynamic pressure distribution and load carrying capacity of the conical slide bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/246488.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical slide bearing
pressure distribution
microgrooves
Reynolds equation
load carrying capacity
Opis:
The aim of this work is to determine the hydrodynamic pressure distribution in oil film and the load carrying capacities of conical slide micro bearings with grooved sleeves. The results for some bearings examples are presented. For the bearings taken into account, the Reynolds equation was solved by the method of Finite Differences. In the calculations, the Reynolds boundary condition was applied. The simulation was performed for the conical slide micro bearings with the groves parallel to the cone generating line. The function of lubrication gap height for the conical slide bearings with sleeves covered with microgrooves was assumed on the basis of existing papers. The results obtained for the analogous bearings without the microgrooves are also shown, therefore the influence of microgrooves on the conical slide micro bearings can be observed. On the basis of the results, one can conclude, that applying microgrooves on the bearing sleeve surface causes the increase of the value of hydrodynamic pressure and longitudinal and transverse components of the load carrying capacity of the bearing. Furthermore, the effect of the microgrooves and their impact is noticeable in graphs of hydrodynamic pressure distribution. The applied method of investigation of the impact of microgrooves on a bearing operation is simpler and less expensive than the experimental studies, however it is necessary to verify that the results obtained with this method are correct and whether in fact applying microgrooves, besides form facilitate lubrication, causes the improvement in bearing operating parameters.
Źródło:
Journal of KONES; 2012, 19, 3; 85-91
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carrying capacity and friction forces in a transverse journal bearing, lubricated with non-Newtonian oil
Autorzy:
Miszczak, A.
Sikora, G.
Powiązania:
https://bibliotekanauki.pl/articles/243066.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
slide journal bearing
hydrodynamic pressure
load carrying capacity
friction force
non-Newtonian oil
Opis:
In this article, the authors present the results of numerical calculations. Calculations concern dimensionless carrying capacity and friction forces in a transverse journal bearing, lubricated by the oil of non-Newtonian properties. For analytical-numerical considerations a model of apparent viscosity changes based on exploitation time, pressure, temperature, shear rate was assumed The non-Newtonian properties of lubricating oil were characterized by increasing viscosity with increasing shear rate and described as an additional part in the constitutive equationβ3·tr(A1 2)A1. Analytical-numerical calculations were performed for smooth, non-porous plain bearing with full angle of wrap. Non-isothermal, laminar and fixed flow of lubricant in the lubrication gap of the journal bearing was assumed. Numerical calculations of hydrodynamic pressure distribution were made for Reynolds boundary conditions. The finite difference method was used to determine the Reynolds equation and the successive approximation method by taking into account the influence of pressure, temperature and non-Newtonian properties on the change of apparent viscosity. The results of the calculations are presented in the form of graphs and tables illustrating the influence of relative eccentricity and pressure, temperature and non-Newtonian properties on changes in the dimensionless load and friction force. Analysis of the obtained results illustrates the high-pressure effect on the increase of the carrying capacity and friction force for high relative eccentricities. A similar situation is by considering the non-Newtonian properties.
Źródło:
Journal of KONES; 2017, 24, 3; 203-210
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł

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