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1
Content available Analysis of dynamical behaviour of full-floating disk thrust bearings
Nitzschke Steffen, Ziese Christian, Woschke Elmar
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2021
|
Vol. 69, nr 6
art. no. e139001
EN
Full-floating ring bearings are state of the art at high speed turbomachinery shafts like in turbochargers. Their main feature is an additional ring between shaft and housing leading to two fluid films in serial arrangement. Analogously, a thrust bearing with an additional separating disk between journal collar and housing can be designed. The disk is allowed to rotate freely only driven by drag torques, while it is radially supported by a short bearing against the journal. This paper addresses this kind of thrust bearing and its implementation into a transient rotor dynamic simulation by solving the Reynolds PDE online during time integration. Special attention is given to the coupling between the different fluid films of this bearing type. Finally, the differences between a coupled and an uncoupled solution are discussed.
2
Content available Effect of surface roughness on steady performance of hydrostatic thrust bearings: Rabinowitsch fluids
Singh Udaya P.
Archive of Mechanical Engineering
|
2021
|
LXVIII, nr 2
147--164
EN
The present theoretical study is concerned with the analysis of surface roughness effects on the steady-state performance of stepped circular hydrostatic thrust bearings lubricated with non-Newtonian fluids: Rabinowitsch fluid model. To take the effects of surface roughness into account, Christensen’s theory for rough surfaces has been adopted. The expression for pressure gradient has been derived in stochastic form employing the energy integral approach. Results for stochastic film pressure and load-carrying capacity have been plotted and analyzed based on numerical results. Due to surface roughness, significant variations in the theoretical results of these properties have been observed.
3
Content available Influence of wall porosity and surfaces roughness on the steady performance of an externally pressurized hydrostatic conical bearing lubricated by a Rabinowitsch fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2017
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Vol. 22, no. 3
717--737
EN
In the paper, the influence of both the bearing surfaces roughness as well as porosity of one bearing surface on the pressure distribution and load-carrying capacity of a curvilinear, externally pressurized, thrust bearing is discussed. The equations of motion of a pseudo-plastic Rabinowitsch fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation and Christensen theory of hydrodynamic lubrication with rough bearing surfaces the modified Reynolds equation is obtained. The analytical solution is presented; as a result one obtains the formulae expressing the pressure distribution and load-carrying capacity. Thrust radial and conical bearings, externally pressurized, are considered as numerical examples.
4
Content available Inertia and couple-stress effects in a curvilinear thrust hydrostatic bearing
Walicka A., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2017
|
Vol. 22, no. 3
759--767
EN
The flow of a couple-stress lubricant in a clearance of a curvilinear thrust hydrostatic bearing with impermeable walls is considered. The flow in the bearing clearance is considered with inertia forces. The equations of motion are solved by an averaged inertia method. As a result, the formulae for pressure distributions without and with inertia effects were obtained. Radial thrust bearings and spherical bearings are discussed as numerical examples. It is shown that inertia effects influence the bearing performance considerably.
5
Content available remote Monitorowanie temperatury łożyska nośnego pionowego hydrozespołu
Nowicki R., Morozov N.
Przegląd Spawalnictwa
|
2016
|
R. 88, nr 10
127--132
PL
Opisano przypadek poważnego uszkodzenia łożyska nośnego pionowego hydro-generatora dużej mocy. Dokonano analizy stosowanego systemu monitorowania i zabezpieczeń dla łożysk oporowych, opisano przyczyny zbyt wolnego zadziałania systemu zabezpieczeń oraz sformułowano wytyczne dla bardziej efektywnego systemu zabezpieczeń.
EN
A serious thrust bearing failure of a high power vertical hydro-generator is described. Analysis of the applied monitoring and protection system for the thrust bearings is provided. Slow response time of the protection system is investigated. A guideline for the more efficient protection system is provided.
6
Content available Thrust porous bearing with rough surfaces lubricated by a rotem-shinnar fluid
Walicka A., Walicki E.
Acta Mechanica et Automatica
|
2016
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Vol. 10, no. 1
50--55
EN
In the paper the influence of both bearing surfaces roughness and porosity of one bearing surface on the pressure distribution and load-carrying capacity of a thrust bearing surfaces is discussed. The equations of motion of a pseudo-plastic fluid of Rotem-Shinnar, are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation and Christensen theory of hydrodynamic lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of squeeze film bearing and externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. Thrust radial bearing with squeezed film is considered as a numerical example.
7
Content available Thrust bearing with rough surfaces lubricated by an Ellis fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2014
|
Vol. 19, no. 4
809--822
EN
In the paper the influence of bearing surfaces roughness on the pressure distribution and load-carrying capacity of a thrust bearing is discussed. The equations of motion of an Ellis pseudo-plastic fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and using the Christensen theory of hydrodynamic rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of a squeeze film bearing and an externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.
8
Content available Porous squeeze film bearing with rough surfaces lubricated by a Bingham fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2014
|
Vol. 19, no. 4
795--808
EN
In the paper the effect of both bearing surfaces and the porosity of one bearing surface on the pressure distribution and load-carrying capacity of a squeeze film bearing is discussed. The equations of motion of a Bingham fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and Christensen theory of rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for a squeeze film bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.
9
Content available remote Pressure distribution in a porous squeeze film bearing lubricated by a simple Casson fluid
Walicka A., Walicki E., Jurczak P.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 3
1039-1049
EN
The influence of a wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated by a lubricant being a viscoplastic fluid of a simple Casson type is considered. After general considerations on the flow of the viscoplastic fluid (lubricant) in a bearing clearance and in a porous layer the modified Reynolds equation for the curvilinear squeeze film bearing with a Casson lubricant is given. The solution of this equation is obtained by a method of successive approximation. As a result one obtains a formula expressing the pressure distribution. The example of squeeze film in a step bearing (modeled by two parallel disks) is discussed in detail.
10
Content available remote Inertia effects in a porous squeeze film bearing lubricated by a Bingham fluid
Walicka A., Walicki E., Jurczak P.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 3
1027-1038
EN
The influence of inertia and wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated by a viscoplastic fluid of a Bingham type is considered. The general consideration on the flow of the viscoplastic fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and an averaged inertia method the modified Reynolds equation for the curvilinear thrust bearing is given. The solution of this equation for the case of the squeeze film bearing is presented. As a result one obtains a formula expressing the pressure distribution. The example of a squeeze film between parallel disks is discussed in detail.
11
Content available Elastohydrodynamic Contact Model for Calculation of Axial and Angular Stiffness in Thrust Bearing
Temis M., Lazarev A.
Archive of Mechanical Engineering
|
2012
|
Vol. LIX, nr 4
453--467
EN
Thrust bearing model is developed for fluid flow calculation and for determination of bearing integral characteristics in the presence of sliding surfaces closure and shaft angular displacements. The model is based on the coupled solution of the problem of incompressible fluid flow between the sliding surfaces and the problem of bearing and shaft elements deformation under the action of the fluid film pressure. Verification of the bearing model results is carried out by the comparison versus the fluid flow calculation results obtained by STAR-CD software and the experimental and theoretical results represented in the certain literature. Thrust bearing characteristics are determined versus sliding surfaces closure and rotating disk (runner) angular displacements. The contribution of the sliding surfaces deformations into bearing integral characteristics is estimated.
PL
Opracowano model łożyska oporowego przeznaczony do obliczeń przepływu płynu i wyznaczania całościowych charakterystyk dla warunków gdy występuje zamknięcie szczeliny między ślizgającymi się powierzchniami i kątowe przemieszczenie wału. Model jest oparty na połączonych rozwiązaniach zagadnienia przepływu nieściśliwego płynu między ślizgającymi się powierzchniami i zagadnienia deformacji elementów łożyska i wału pod wpływem ciśnienia w warstwie płynu. Weryfikacja wyników modelu łożyska jest przeprowadzona przez ich porównanie z wynikami obliczeń przepływu płynu uzyskanymi przy użyciu oprogramowania STAR-CD oraz wynikami eksperymentalnymi i teoretycznymi podawanymi w literaturze. Charakterystyki łożyska ślizgowego są wyznaczone z uwzględnieniem zamknięcia szczeliny smarnej i przemieszczeń kątowych tarczy obrotowej (oporowej). Oszacowano wpływ, jaki mają odkształcenia ślizgających się powierzchni na całościowe charakterystyki łożyska.
12
Content available remote Pressure distribution in the hydrostatic thrust bearing lubricated by a generalized second grade lubricant of a power-law type
Walicka A.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no 4
1225-1235
EN
The flow of a generalized second grade lubricant of a power-law type in a clearance of the thrust curvilinear bearing is considered. To solve this problem the boundary layer equations expressed for axially symmetric case in a curvilinear orthogonal coordinate system connected with one of the bearing surfaces by used. The method of averaging inertia and viscoplastic terms is used to find the solution of the boundary layer equations. As a result the formula for pressure distribution is obtained. Examples the lubricant flow in step and spherical hydrostatic bearings are given.
13
Content available remote Pressure distribution in a porous curvilinear squeeze film bearing lubricated by a Bingham fluid
Walicka A.
International Journal of Applied Mechanics and Engineering
|
2011
|
Vol. 16, no 4
1215-1224
EN
The influence of a wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated by a viscoplastic fluid of a Bingham type is considered. The general consideration on the flow of viscoplastic fluid in a bearing clearance and in a porous layer are presented. The modified Reynolds equation for the curvilinear thrust bearing is given. The solution of this equation for the case of the squeeze film bearing is presented. As a result one obtains a formula expressing the pressure distribution. The example of a squeeze film between parallel disks is discussed in detail.
14
Awarie pomp HALBERG typu HMO 100x6
Błaszczyk A.
Energetyka Cieplna i Zawodowa
|
2009
|
Nr 11
54--57
PL
W warunkach zainstalowania i eksploatacji pompy Halberg HMO100x6 dochodziło do nadmiernego grzania i awarii zespołu łożyska oporowego. Przedstawione poniżej wyniki analiz związane są z ustaleniem przyczyn tej sytuacji i propozycją rozwiązania zapewniającego prawidłową pracę pompy.
15
Content available remote Couple-stress and surface roughness effects in curvilinear thrust bearings with a porous pad
Walicka A., Walicki E., Jurczak P., Michalski D.
International Journal of Applied Mechanics and Engineering
|
2008
|
Vol. 13, no 2
563-574
EN
On the basic of Christensen's stochastic model of rough surfaces, different forms of Reynolds equation with rotational inertia effect are obtained for various types of surface roughness pattern and for couple stress lubricant. As results one obtained the formulae expressing the mean film pressure distribution for externally pressurized bearings and for bearings with a squeeze film. An example of step bearing is considered.
16
Content available remote Analysis of tilting pads thrust bearings behavior lubricated by power law fluid
Souchet D., Bouyahia F., Hajjam M., El Khlifi M.
International Journal of Applied Mechanics and Engineering
|
2005
|
Vol. 10, no spec
297-302
EN
The numerical modeling of non-Newtonian lubricant flows in titling pads thrust bearing is developed to predict some interesting factors in industrial view point. It means parameters such as load, friction and power loss whose evaluation contributes strongly to improve the design and performances of the titling pads thrust bearing. The non-Newtonian rheological model chosen is the power law because of its large domain of use. The dynamic field is described through the resolution of the generalized Reynolds equation and the thermal effects, due to the lubricant shearing, is taken into account through a global thermal balance. The discretisation of equations is made by the finite differences scheme.
17
Content available remote Rotational inertia and roughness effect in curvilinear thrust bearings
Walicka A., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no spec.
329-336
EN
On the basis of Christensen's stochastic model of rough surfaces, different forms of Reynolds equation with rotational inertia effect are obtained for various types of surface roughness pattern and for Newtonian lubricant. As results one obtained the generalized formulae expressing the mean pressure distribution and load capacity for externally pressurized bearings. A spherical bearing is discussed as an example.
18
Content available remote Performance of a thrust bearing lubricated by a Bingham ferromagnetic lubricant
Walicka A., Wilewski B.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no spec.
345-352
EN
The effects of centrifugal inertia forces on the pressure distribution in the curvilinear thrust bearing lubricated by a ferromagnetic viscoplastic lubricant of a Bingham type are examined. The examples of flows in the bearing modelled by and two concentric spheres are considered. The results obtained show that ferrofluid inertia forces and magnetization have significant effects on the pressure distributions and on the load-capacity.
19
Content available remote Inertia effect in the curvilinear thrust bearing lubricated by a power-law ferrofluid
Walicka A., Wilewski B.
International Journal of Applied Mechanics and Engineering
|
2004
|
Vol. 9, no spec.
337-344
EN
The effects of centrifugal inertia forces on the pressure distribution in the curvilinear thrust bearing lubricated by a power-law ferrofluid are examined. The examples of flows in the bearings modelled by two disks and two concentric spheres are considered. The results obtained show that ferrofluid inertia forces and magnetization have significant effects on the pressure distributions.
20
Content available remote Numerical modeling and design of a wavy thrust bearing
Choy F. K., Braun M. J., Zhao H.
International Journal of Applied Mechanics and Engineering
|
2002
|
Vol. 7, no 3
757-769
EN
The objective of this paper is to present the analytical and numerical development leading to the simulation of a wavy thrust bearings. The analytical formulation is based on the application of the Reynolds equation to the geometry of two parallel circular plates with prescribed boundary conditions at their inner and outer circumferential edges. The upper plate is assumed to be rotating while the lower plate, which is wavy in geometry, is stationary. A numerical procedure based on the discretisation of the Reynolds equation yields a finite difference formulation that reduces the second order partial differential equation to a set of simultaneous algebraic equations. For a given loading condition, the equilibrium position of the rotating plate is evaluated using the Newton-Raphson search, by balancing the applied load with the force generated by the hydrodynamic fluid film resisting pressure. The stiffness of the bearing is then calculated using a numerical small perturbation procedure at the equilibrium position of the upper plate. Finally the transient motion of the journal is evaluated using a numerical integration scheme on the translational and angular acceleration parameters. General and specific conclusions are drawn based on these numerical results.
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