Relation between Theory, Experiment, and Practice in Journal Bearing Design

1935 ◽  
Vol 129 (1) ◽  
pp. 435-475
Author(s):  
H. L. Haslegrave

The first section of the paper is devoted to the correlation of experimental and theoretical research on journal bearings embracing the angles of 360 deg., 180 deg., and 120 deg., and attempts to combine hitherto isolated experimental data by making use of the results of Kingsbury's experiments based upon an electrical analogy. The possible causes of divergence in the results obtained by different workers are enumerated and their effect on the general agreement explained. There is considerable experimental evidence to support the basic principles of the method of design derived in the preceding paper by Dr. Swift. The second section analyses current methods of design in the light of these principles, and explains the reasons for departure from the theoretical method in some cases. Particulars relating to journal bearings used in various types of machines are tabulated, and values of the dimensionless criteria used in actual practice are compared with those suggested by theory. Design examples are worked out, and results tabulated, in order to explain the methods which may be employed in order to secure optimum running conditions in various circumstances, and their resultant effect on performance. A summary is given in the last section of the existing state of knowledge relating to journal bearings, considered from the point of view of the designer. Further data still necessary are enumerated and the avenues of research yet to be explored in order to obtain this knowledge are explained.

Author(s):  
S. Strzelecki ◽  
Z. Towarek

The design of turbines and compressors operating at the high rotational speeds applies the 3-lobe journal bearings. In many cases the classic 3-lobe journal bearings supporting the rotors, are showing the problem of rotor stability. This problem can be avoided by the application of 3-lobe Offset bearings. This type of bearing fulfils the conditions of reliable bearing design and good stability in the case of high speed rotating machines.


2017 ◽  
Vol 69 (5) ◽  
pp. 754-760 ◽  
Author(s):  
Nimeshchandra S. Patel ◽  
Dipak Vakharia ◽  
Gunamani Deheri

Purpose This paper aims to investigate the performance of a ferrofluid-based hydrodynamic journal bearing system. Design/methodology/approach This paper presents a new design of ferrofluid-based hydrodynamic journal bearing. An experimental set-up consisting of a magnetic shaft along with a brass bearing was modified and developed. A permanent magnet was used to make the selected shaft material magnetic. The load and speed were varied to conduct the analyses for different test conditions. Findings The paper provides information about a design of ferrofluid-based journal bearing and its improved performances. For moderate to higher loads at different shaft speeds, it was found that because of the magnetization effect, the maximum film pressure in case of a ferrofluid lubricant increased up to approximately 60 per cent, compared with that of the conventional lubricant-based journal bearing system. Besides, the temperature rise was found smaller for ferrofluid lubricants, thus making the system cooler while running. Originality/value This paper offers a new design of magnetic bearing system for the experimental analysis by utilizing a magnetic shaft with a non-magnetic bearing. The present ferrofluid-based bearing design is less complicated from manufacturing point of view.


2013 ◽  
Vol 364 ◽  
pp. 71-75
Author(s):  
Ming Hu Yin ◽  
Guo Ding Chen ◽  
Guo Yuan Zhang

Most of the studies about tilting pad journal bearings are for load-on-pad or load-between-pad tilting pad journal bearings, and for the other loading forms, the performance are often estimated by the performance of the two limited conditions, that may reduce the reliablity of bearing design or lead to waste materials in design. To obtained the influence of the load directions on the static and dynamic characteristics of the tilting pad journal bearing, which is called eccentric load effect in this papers, the performance calculation of the tilting pad journal bearing in different load directions is operated with a self-designed program. The results show that the load directions have considerable effects both on the static and dynamic characteristics of the tilting pad journal bearing, for the operating condition that load direction changed rapidly, it need performance analysis of the bearing in its special loading forms to enhance the precision and efficiency of bearing design, espacially where the dynamic performance of the tilting pad journal bearing is demanding.


1999 ◽  
Vol 121 (3) ◽  
pp. 604-609 ◽  
Author(s):  
E. S. Piekos ◽  
K. S. Breuer

A journal bearing simulation tool developed to aid the design of the MIT microturbo-machine bearings is described. This tool uses an orbit method with a pseudospectral technique for treating the Reynolds equation. Comparison is made to various published data. Two types of stability chart are presented and their application to turbo-machine bearing design is discussed. Simulations of imbalance, noncircular geometry, and nonuniform pressures at the bearing ends are also demonstrated.


1969 ◽  
Vol 91 (3) ◽  
pp. 516-521 ◽  
Author(s):  
A. Seireg ◽  
H. Ezzat

This paper presents an automated system for the selection of the length, clearance, and lubricant viscosity which optimize the performance of a hydrodynamic journal bearing, under specified values or ranges of load and speed. The study illustrates the feasibility of applying optimal programming techniques for the development of bearing design systems.


Author(s):  
E Solmaz ◽  
F C Babalik ◽  
F Öztürk

The solutions that best optimize the design process must be determined using single-criterion and multicriteria approaches. In this research, a multicriteria optimization approach is carried out to determine the circular hydrostatic journal bearing design parameters based on the power requirement, the bearing coefficient and the minimization of the temperature rise of the oil, so that the total performance of the system is optimal. The optimization results of more than two criteria are presented and compared with previous research outcomes. Computational experimental results are given to demonstrate the effectiveness of the present approach.


Author(s):  
Jiale Tian ◽  
Baisong Yang ◽  
Lie Yu ◽  
Jian Zhou

As one of the most important components in a rotor-bearing system, journal bearings provide proper support and damping to the rotor so that it can run both smoothly and efficiently and keep stable under different working conditions. As the rotating speed of the rotor growing faster and load getting heavier, the traditional cylinder journal bearing can no longer meet the demand of stabilizing the rotor, so different kinds of non-circular journal bearings were invented, such as elliptical bearing, multi-lobe bearing, wave bearing and etc., to provide better stability and greater load capacity. However, these kinds of non-circular bearings were mostly designed by experience of the engineers, and also the current hydrodynamic bearing design methodology still depends on empirical design. There lacks of corresponding theoretical foundation. In order to develop a theoretical method for bearing designing, an innovative analyzing approach needs to be carried out to explore the mechanism of the bearings and its performance. In this paper, a new approach is presented focusing on the profile of each bearing and their film thickness. A universal mathematical expression for different types of non-circular bearings has been put forward based on the Fourier series theory. The influence of periodic harmonics of film thickness on the static performance of non-circular bearings of finite length is studied for incompressible lubricant. The results show that the film thickness can always be expanded into a Fourier series, and the harmonic components of film pressure can be obtained by solving the Reynolds equation. Finally, the relation between the k-th order harmonic component H0,k and the corresponding static pressure component P0,k is established. This new investigation can be used to improve the non-circular bearing designing methodology with theoretical guidance.


Author(s):  
M Malik

A new type of gas-lubricated floating-ring journal bearing in which the fixed bearing and the ring are both porous, has been conceived and analysed, theoretically, for the steady state characteristics. Bearing characteristics are presented against two design parameters, namely, clearances ratio and permeability parameter. The comparison of these characteristics with those of externally-pressurized plain porous journal bearings shows that the new bearing represents, with its steady state performance, a distinctly advanced bearing design.


2006 ◽  
Vol 13 (4-5) ◽  
pp. 285-300 ◽  
Author(s):  
Miguel Angelo de Carvalho Michalski ◽  
Moysés Zindeluk ◽  
Renato de Oliveira Rocha

Journal bearing design and the lubricant characteristics are very influential in a rotating machine behaviour. The bearing geometry can drastically affect the lubricant flow and also the rotor dynamics. Approaching that issue, this paper presents an experimental study of the dynamic behavior of a horizontal rotor suported by journal bearings with semi-circular axial grooves. The journal bearings were manufactured with a varied number of axial grooves and a versatile test rig is used, making possible the analysis of different configurations. The acquired signals are analyzed with classical and non-linear tools and the differences among the rotors’ configurations can be shown.


The success of the Program of housing stock renovation in Moscow depends on the efficiency of resource management. One of the main urban planning documents that determine the nature of the reorganization of residential areas included in the Program of renovation is the territory planning project. The implementation of the planning project is a complex process that has a time point of its beginning and end, and also includes a set of interdependent parallel-sequential activities. From an organizational point of view, it is convenient to use network planning and management methods for project implementation. These methods are based on the construction of network models, including its varieties – a Gantt chart. A special application has been developed to simulate the implementation of planning projects. The article describes the basic principles and elements of modeling. The list of the main implementation parameters of the Program of renovation obtained with the help of the developed software for modeling is presented. The variants of using the results obtained for a comprehensive analysis of the implementation of large-scale urban projects are proposed.


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