STATIC CHARACTERISTICS OF OFFSET 8-LOBE JOURNAL BEARINGS

Tribologia ◽  
2021 ◽  
Vol 295 (1) ◽  
pp. 39-51
Author(s):  
Stanisław Strzelecki
Keyword(s):  
Laminar Flow ◽  
Equilibrium Position ◽  
Iterative Procedure ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Diameter Ratio ◽  
Static Characteristics ◽  
Oil Film ◽  
Cooling Conditions ◽  
Grinding Machines

The 8-lobe journal bearings have found application in the bearing systems of spindles of grinding machines. The design of bearings and the large number of lobes and oil grooves assures good cooling conditions of bearing. These bearings can be manufactured as the bearings with cylindrical, non-continuous operating surfaces separated by six lubricating grooves, bearings with the pericycloidal shape of the bearing bore, and as offset journal bearing. This paper presents the results of the computation of static characteristics of an offset 8-lobe journal bearing operating under the conditions of an aligned axis of journal and bush, adiabatic oil film, and at the static equilibrium position of journal. Different values of bearing length to diameter ratio, relative clearance, and lobe relative clearance were assumed. Reynolds' energy and viscosity equations were solved by means of an iterative procedure. Adiabatic oil film, laminar flow in the bearing gap, and aligned orientation of journal in the bearing were considered.

MAXIMUM OIL FILM TEMPERATURE OF A 4-LOBE JOURNAL BEARING WITH THE LOBES OF SMALL ANGULAR LENGTH

Tribologia ◽  
2017 ◽  
pp. 87-92
Author(s):  
Stanisław STRZELECKI
Keyword(s):  
Equilibrium Position ◽  
Journal Bearing ◽  
Thermal State ◽  
Iterative Solution ◽  
Journal Bearings ◽  
Maximum Temperature ◽  
Static Characteristics ◽  
Oil Film ◽  
Grinding Machine ◽  
Oil Film Pressure

Multilobed journal bearings with the lobes of small angular length are often applied in the bearing systems of grinding machine spindles, which is the most important assembly in the grinding machine. The safe operations of such bearings at proper oil film temperature can be assured by the knowledge of thermal state of bearing and its maximum temperature. This paper presents the results of the calculations of some static characteristics of a 4-lobe bearing with the lobes of small angular length and particularly its maximum oil film temperature. The oil film pressure, temperature, and viscosity fields were obtained by an iterative solution of the Reynolds', energy, and viscosity equations. Adiabatic, laminar oil film and the static equilibrium position of journal were assumed.

Single-Axial Groove Journal Bearings: Static Characteristics and a Temperature Prediction Technique

1996 ◽  
Vol 210 (1) ◽  
pp. 45-53 ◽  
Author(s):  
P Pliakas ◽  
D W Parkins
Keyword(s):  
Journal Bearing ◽  
Journal Bearings ◽  
Measured Data ◽  
Diameter Ratio ◽  
Temperature Profiles ◽  
Measured Temperature ◽  
Static Characteristics ◽  
Prediction Technique ◽  
Load Vector ◽  
Hydrodynamic Journal Bearing

This paper describes measured data for the static characteristics of a plain hydrodynamic journal bearing with a single-axial oil supply groove located in the direction of the load vector. The journal centre static locus was measured for a variety of speed/load combinations with three values of length-diameter ratio. Full descriptions of the experimental procedures are given. Comparison is made with corresponding data from the appropriate ESDU data item. An extensive set of oil-film temperatures were also taken at each test condition. Empirical equations were established from these measured temperature profiles. These were shown to reliably predict the complete temperature field, together with the maximum and its location, over the entire experimental range. Equations are formulated in a manner that is usable by the designer.

Effect of Oil Supply Pressure on the Maximum Oil Film Temperature of 2-Lobe Journal Bearing

2005 ◽  
Author(s):  
S. Strzelecki ◽  
H. Kapusta ◽  
J. Swiatek
Keyword(s):  
Journal Bearing ◽  
Iterative Solution ◽  
Journal Bearings ◽  
Steam Turbines ◽  
Film Pressure ◽  
Oil Film ◽  
Oil Supply ◽  
Supply Pressure ◽  
Cooling Conditions ◽  
Oil Film Pressure

Two-lobe journal bearings are applied in the responsible bearing systems of steam turbines, turbogenerators and compressors. As compare to the bearing with the cylindrical bush they have better stability in the range of higher rotational velocities and loads simultaneously assuring very good cooling conditions for the oil film. For the two-lobe journal bearing the oil film pressure, temperature and viscosity distributions have been obtained by iterative solution of the Reynolds’, energy and viscosity equations. An effect of supplied oil pressure on the maximum oil film temperature was investigated.

The Influence of Surface Roughness on Elastohydrodynamic Journal Bearing With Non-Newtonian Lubricants

2005 ◽  
Author(s):  
Mongkol Mongkolwongrojn ◽  
Chatchai Aiumpornsin ◽  
Somnuk Yawong
Keyword(s):  
Surface Roughness ◽  
Elastic Deformation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Elastohydrodynamic Lubrication ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Static Characteristics ◽  
Heavy Load ◽  
Oil Film

In this paper, the effect of surface roughness and elastic deformation of bearing liner on the static characteristics of journal bearings are presented. A power law model is developed for the elastohydrodynamic lubrication regime. The modified Reynolds equations with elasticity equation were formulated for the elastohydrodynamic journal bearings under heavy load conditions. Multigrid and multilevel technique with Newton’s method were used to calculated the elastohydrodynamic bearing to obtain the oil film pressure profile, oil film thickness profile, load capacity, attitude angle and friction coefficient at various surface roughness parameters. The static characteristics of the rough elastohydrodynamic journal bearing were compared with that of the rough hydrodynamic journal bearings. The results show that the surface roughness and elastic deformation significantly affect the static characteristics of journal bearings under severe operating conditions.

Experimentally study of dynamic pressure distribution and oil film forces in journal bearing using ElectroMechanical Film sensor array

2019 ◽  
Vol 234 (4) ◽  
pp. 903-913
Author(s):  
Changmin Chen ◽  
Jianping Jing ◽  
Jiqing Cong ◽  
Chao Ji
Keyword(s):  
Pressure Distribution ◽  
Sensor Array ◽  
Journal Bearing ◽  
Dynamic Pressure ◽  
Vertical Direction ◽  
Journal Bearings ◽  
Film Sensor ◽  
Film Pressure ◽  
Oil Film ◽  
Oil Film Pressure

The acquisition of the oil film pressure and forces on the bearing pads through experimentation is crucial to understanding the characteristics of journal bearing. Lots of efforts had been taken in film pressure measurement, and the pressure was obtained at specified position on the bearing pads. However, due to the space and structure constraint, merely very limited number of the point pressure can be obtained with traditional sensors and acquiring the detail pressure field on whole bearing pad surface is still an open challenge. In this paper, a method based on thin-film sensors technique is proposed and employed to measure the pressure distribution and oil film forces of journal bearings. The measurement is conducted on a cylindrical journal bearing with two axial grooves, and ElectroMechanical Film sensor arrays are designed and laid on the surface of the bearing pads. The oil film pressure is acquired at up to 32 measurement points in total along the bearing pads in both circumference and axial directions. The pressure distribution in a wide rotation speed range is obtained successfully by using fitting algorithm. Furthermore, the oil film forces on horizon and vertical direction are obtained through the integration of the measured pressure filed. The test results prove that it is feasible to measure the oil pressure filed of journal bearings using ElectroMechanical Film piezo-film sensor array.

Power Loss of Tilting 5-Pad Journal Bearing Operating With Turbulent Oil Film

2005 ◽  
Author(s):  
S. Strzelecki
Keyword(s):  
Power Loss ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Heavy Duty ◽  
Safe Operation ◽  
Oil Film ◽  
Full Knowledge

Journal bearings of high speed turbocompressors, compressors and heavy duty high speed turbine gearboxes operate at journal peripheral speeds like 150 m/s. The flow of lubricant in such bearings is not laminar but super laminar or turbulent. It results in the increase in power loss and in the decrease of the bearing stability. The ground for the safe operation of high speed journal bearings at proper oil film temperature and with less power loss is the full knowledge of bearing performances at the turbulent oil film.

Nonlinear Dynamic Oil-Film Forces in Infinite-Short Journal Bearings

2011 ◽  
Author(s):  
Lihua Yang ◽  
Weimin Wang ◽  
Lie Yu
Keyword(s):  
Nonlinear Dynamic ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Analytic Solutions ◽  
Journal Bearings ◽  
Oil Film ◽  
Dynamic Coefficients ◽  
Representation Model ◽  
Linear And Nonlinear

In this paper, the analytic solutions of oil-film forces in infinite-short cylindrical journal bearing are calculated by solving its corresponding Reynolds equation. On this base, the linear and nonlinear dynamic coefficients of the bearing are predicted. By comparing the dynamic oil-film forces approximately represented by dynamic coefficients with the analytic solutions, the accuracy of this representation model is investigated. The results show that more orders of dynamic coefficients are included in representation model, the obtained approximate oil-film forces are more close to their analytic solutions. This can be a reference to illustrate the feasibility and applicability of representing oil-film forces by applying the dynamic coefficients of bearings.

Static Characteristics of the Regular and Reversible Rotation Type Herringbone Grooved Journal Bearing

1989 ◽  
Vol 111 (3) ◽  
pp. 484-490 ◽  
Author(s):  
Nobuyoshi Kawabata ◽  
Yasumi Ozawa ◽  
Shuji Kamaya ◽  
Yutaka Miyake
Keyword(s):  
Numerical Analysis ◽  
Journal Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Radial Load ◽  
Static Characteristics ◽  
Oil Film ◽  
New Type ◽  
Load Component ◽  
Reversible Rotation

A new type herringbone grooved journal bearing, which produces an oil film bearing pressure with a shaft or bearing rotation in either direction, is proposed in this paper. A numerical analysis of the bearing parameters using the narrow groove theory and the Gu¨mbel condition confirmed that the load capacity of this bearing and the radial load component (related to stability) do not differ greatly from those of a conventional bearing. The values of the bearing parameters which give maximum load capacity, and the values of the load capacity and its direction angle are also determined numerically for the case of either grooved member or smooth member rotation.

Stability of Jeffcott Rotor Operating in Tilting 3-Pad Journal Bearings with Turbulent Oil Film

2009 ◽  
Vol 147-149 ◽  
pp. 450-455
Author(s):  
Stanislaw Strzelecki ◽  
Sobhy M. Ghoneam
Keyword(s):  
Theoretical Investigation ◽  
Dynamic Characteristics ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Oil Film ◽  
Temperature Distributions ◽  
Jeffcott Rotor ◽  
Oil Flow ◽  
The Stability ◽  
Oil Film Pressure

This paper introduces the results of theoretical investigation on the dynamic characteristics of tilting 3-pad journal bearing that operates with turbulent oil film. The Reynolds, energy, viscosity and geometry equations determine the oil film pressure, temperature distributions, and oil film resultant force that are the grounds for the dynamic characteristics of bearing. These equations were solved simultaneously on the assumption of adiabatic laminar or adiabatic turbulent oil flow in the bearing gap. The stability and system damping of Jeffcott rotor operating in tilting 3-pad journal bearing was determined.

scholarly journals The effect of oil feeding type and oil grade on the oil film bearing capacity

2021 ◽  
Vol 23 (2) ◽  
pp. 381-386
Author(s):  
Aleksander Mazurkow ◽  
Waldemar Witkowski ◽  
Adam Kalina ◽  
Bartłomiej Wierzba ◽  
Mariusz Oleksy
Keyword(s):  
Bearing Capacity ◽  
Journal Bearings ◽  
Maximum Temperature ◽  
Maximum Pressure ◽  
Static Characteristics ◽  
Oil Film ◽  
Feeding Type ◽  
Oil Flow ◽  
Minimum Height ◽  
Face Side

Two types of hydrodynamically lubricated plain journal bearings were subject to examination differing in the method used to feed them with oil. The first type was fed from a lubrication pocket and the second from the bearing face side. Mathematical models were developed with two-way oil flow allowing to determine the oil film bearing capacity, the maximum pressure, the maximum temperature, and the film oil minimum height for given position of journal relative to solid bush. Static characteristics were developed used in the further course of the study to compare operating parameters of the considered types of bearings. Another issue considered in the paper is the effect of oil VG grade on bearing performance with conditions of oil feeding taken into account and results of the research presented.

Sign in / Sign up

Export Citation Format

Share Document