Wyniki wyszukiwania - BazTech

1

Distributions of hydrodynamic pressure in the gap of slide journal bearing lubricated with ferro-oil

Frycz Marcin

Journal of KONES

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2019

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Vol. 26, No. 4

53--61

EN

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.

2

Velocity distribution in slide journal bearing gap by laminar unsteady lubrication

Krasowski P.

Journal of KONES

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2011

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Vol. 18, No. 3

177-184

EN

This paper shows results of numerical solutions the modified Reynolds equations for laminar unsteady oil flow in slide journal bearing gap. Laminar unsteady oil flow is performed during periodic and unperiodic perturbations of bearing load or is caused by the changes of gap height in time. Above perturbations occur mostly during the starting and stopping of machine. During modelling crossbar bearing operations in combustion engines, bearing movement perturbations from engine vertical vibrations causes velocity flow perturbations of lubricating oil on the bearing race and on the bearing slider in the circumferential direction. This solution example applies to isothermal bearing model with infinity length. Lubricating oil used in this model has Newtonian properties and constant dynamic viscosity. Perturbations connected with unsteady lubricating oil velocity in the circumferential direction on the slide bearing and on the slider of bearing were taken into consideration. Results are presented in the dimensionless hydrodynamic pressure and velocity distribution diagrams. Received solutions were compared with the solution received by the stationary lubrication flow in the slide journal bearing, which were made with the same parameter assumption by constant dynamic oil viscosity. Isothermal bearing model is similar to friction node model by steady-state heat load conditions.

3

Ciśnienie i prędkość przepływu oleju w łożysku ślizgowym przy niestacjonarnym laminarnym smarowaniu

Krasowski P.

Tribologia

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2009

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nr 6

45-57

PL

W artykule przedstawiono wyniki rozwiązania zmodyfikowanego ciągu równań Reynoldsa opisującego laminarny niestacjonarny przepływ oleju smarującego w szczelinie smarnej poprzecznego cylindrycznego łożyska ślizgowego. Wyniki tych rozwiązań umożliwiają wyznaczenie rozkładu prędkości oleju w kierunku wzdłużnym łożyska. Uwzględniono niestacjonarne zaburzenia prędkości przepływu oleju w kierunku obwodowym na powierzchni czopa i panewki łożyska. Wyniki rozwiązania dotyczą izotermicznego modelu łożyska o nieskończonej długości smarowanego olejem o stałej lepkości dynamicznej.

EN

This paper shows the results of numerical solutions of modified Reynolds equations for laminar unsteady oil flow in the slide journal-bearing gap. Laminar unsteady oil flow is performed during periodic and non-periodic perturbations of bearing load or is caused by the changes of gap height in time. Above perturbations occur mostly during the starting and stopping of the machine. During modelling crossbar-bearing operations in combustion engines, bearing movement perturbations from engine vertical vibrations causes velocity flow perturbations of lubricating oil on the bearing race and on the bearing slider in the circumferential direction. This solution example applies to an isothermal bearing model with infinite length. Lubricating oil used in this model has Newtonian properties and constant dynamic viscosity. Perturbations connected with unsteady lubricating oil velocity in the circumferential direction on the slide bearing and on the slider of bearings were taken into consideration. This article also analyses pressure and velocity distributions in the bearing in the time function during the perturbation. Results are presented in the dimensionless hydrodynamic pressure and velocity distribution diagrams. Diagrams also present the velocity change during the moment of perturbations. Velocity position during perturbation was also analysed. Received solutions were compared with the solution received by the stationary lubrication flow in the slide journal bearing, which were made with the same parameter assumption by constant dynamic oil viscosity. The isothermal bearing model is similar to the friction node model by steady-state heat load conditions.

4

Pressure and velocity distribution in slide journal bearing gap by laminar unsteady lubrication

Krasowski P.

Journal of KONES

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2009

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Vol. 16, No. 2

239-246

EN

This paper shows results of numerical solutions an modified Reynolds equations for laminar unsteady oil flow in slide Journal bearing gap. Laminar unsteady oil flow is performed during periodic and a periodic perturbations of bearing load or is caused by the changes of gap height in time. Above perturbations occur mostly during the starting and stopping of machine. During modelling crossbar bearing operations in combustion engines, bearing movement perturbations from engine vertical vibrations causes velocity flow perturbations of lubricating oil on the bearing race and on the bearing slider in the circumferential direction. This solution example applies to isothermal bearing model with infinity length. Lubricating oil used in this model has Newtonian properties and constant dynamic viscosity. Perturbations connected with unsteady lubricating oil velocity in the circumferential direction on the slide bearing and on the slider of bearing were taken into consideration. Results are presented in the dimensionless hydrodynamic pressure and velocity distribution diagrams. Received solutions were compared with the solution received by the stationary lubrication flow in the slide Journal bearing, which were made with the same parameter assumption by constant dynamic oil viscosity. Isothermal bearing model is similar to friction node model by steady-state heat load conditions.

5

Nekotorye voprosy dinamiki rotorov v gidrodinamiceskih podsipnikah

Podolskii M.

Zeszyty Naukowe Politechniki Świętokrzyskiej. Nauki Techniczne

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2008

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Z. 10, Vol. 1

173-179

EN

Various ways of solving problems of oil film hydrodynamics with local inertia forces are investigated. Compact formulae for hydrodynamical reaction are received. On the base of these formulae several problems concerning synchronous precession and rotor stability are considered.