Optimization of Clearance in a Squeeze-Film Journal Bearing

1971 ◽  
Vol 93 (2) ◽  
pp. 246-251
Author(s):  
C. L. Strodtman
Keyword(s):  
Numerical Methods ◽  
Small Parameter ◽  
Shape Factor ◽  
Journal Bearing ◽  
Diameter Ratio ◽  
Parameter Analysis ◽  
Squeeze Film ◽  
Clearance Ratio ◽  
Proper Selection ◽  
Selection Of

It is shown that a squeeze-film journal bearing supporting a mass completely contained within the bearing can be designed with the optimum value of minimum clearance by proper selection of the drive amplitude to nominal clearance ratio, the length to diameter ratio, and the shape factor of the excursion. Both a small parameter and an augmented, small parameter analysis are given. In the latter case, numerical methods are employed to solve the resulting equations. The results of the analysis are illustrated in application to an accelerometer design.

Load Support of the Squeeze-Film Journal Bearing of Finite Length

1968 ◽  
Vol 90 (1) ◽  
pp. 157-161 ◽  
Author(s):  
J. V. Beck ◽  
C. L. Strodtman
Keyword(s):  
Finite Difference ◽  
Small Parameter ◽  
Pressure Distribution ◽  
Journal Bearing ◽  
Unit Area ◽  
Parameter Analysis ◽  
Squeeze Film ◽  
Axial Pressure ◽  
Finite Difference Technique ◽  
Additive Term

Despite intuition, the squeeze-film bearing of finite dimensions produces much more load support per unit area than is found from a solution based on an infinite bearing. The load support is shown to be made up of two components—that due to the infinite journal plus an additive term due to the axial pressure distribution. Two methods of solution of the governing equation are applied: (a) A small-parameter analysis and (b) a numerical finite-difference technique. In the limit, the infinitely short journal is shown to have a load support 2.5 times that of the infinitely long journal.

An Augmented, Small-Parameter Equation for the Squeeze-Film Journal Bearing

1970 ◽  
Vol 92 (3) ◽  
pp. 442-449 ◽  
Author(s):  
C. L. Strodtman
Keyword(s):  
Small Parameter ◽  
Shape Factor ◽  
Radial Displacement ◽  
Journal Bearing ◽  
Numerical Procedure ◽  
Squeeze Film ◽  
Mean Square ◽  
Root Mean Square Amplitude ◽  
Parameter Equation ◽  
Good Agreement

The asymptotic gas film equation for the squeeze-film journal bearing is solved for the quadratic and cubic terms in the series expansion in terms of the radial displacement. The load support calculated from this augmented, small parameter equation is compared to calculations from an all numerical procedure. Good agreement is shown to exist for large values of the radial displacement. A method of treating nonuniform excursion of the driving member by a root-mean-square amplitude and a shape factor is also given.

The Characteristics of a Statically Loaded Journal Bearing with Superlaminar Flow

1980 ◽  
Vol 22 (2) ◽  
pp. 79-94 ◽  
Author(s):  
R. E. Hinton ◽  
J. B. Roberts
Keyword(s):  
Friction Factor ◽  
Journal Bearing ◽  
Load Capacity ◽  
Reynolds Numbers ◽  
Diameter Ratio ◽  
Experimental Results ◽  
Empirical Theory ◽  
Clearance Ratio ◽  
Friction Factors ◽  
Theoretical Predictions

Experimental results are presented, relating to the friction factor, load capacity and attitude angle, for a plain, cylindrical journal bearing with a central, circumferential inlet groove. The length to diameter ratio of the journal bearing was 1/3 and the clearance ratio was 0.011. By the use of various lubricants, including water, Reynolds numbers ranging from 40 to 50 000 were attained. Comparisons with various theoretical predictions are given. It is shown that a simple, empirical theory, which incorporates measured friction factors, gives better agreement with the experimental load capacity results than previous theories.

Design Embodiments Using Squeeze-Film Phenomenon to Attain Complete Separation of Contacting Surfaces

2020 ◽  
Author(s):  
Cristinel Mares ◽  
Mark Atherton ◽  
Masaaki Miyatake ◽  
Tadeusz Stolarski
Keyword(s):  
Numerical Methods ◽  
Journal Bearing ◽  
Stokes Equations ◽  
Computer Modelling ◽  
Analytical Description ◽  
Complete Separation ◽  
Numerical Results ◽  
Squeeze Film ◽  
Navier Stokes ◽  
Navier Stokes Equations

In this paper four design embodiments that employ SFL to separate surfaces are explored. Section 2 details the fundamental principles of levitation based on SFL and associated Navier-Stokes equations. Section 3 describes four design embodiments utilising squeeze-film mechanism, namely a journal bearing, flexible frame, plain levitating plate and a non-contact gripper, in terms of their analytical description plus experimental and numerical results. Section 4 concludes the paper. The paper demonstrates that the squeeze-film levitation is a feasible idea and can be implemented by a number of different embodiments. The mechanism of levitation is quite complex, and its computer modelling requires advanced numerical methods. All designs presented have been numerically modelled and the outcomes experimentally validated, which can be considered as the main contribution of this article.

Analytical and Experimental Study of Externally Pressurized Air Lubricated Journal Bearings

1962 ◽  
Vol 84 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Jason R. Lemon
Keyword(s):  
Journal Bearing ◽  
Design Parameters ◽  
Radial Clearance ◽  
Proper Selection ◽  
One Dimensional ◽  
Supply Pressure ◽  
Bearing Stiffness ◽  
Bearing Design ◽  
Gas Journal Bearing ◽  
Selection Of

A simplified analysis for calculating the characteristics, such as stiffness, flow, and load of an externally pressurized gas journal bearing, is obtained through a standard one-dimensional flow approach altered to take into account the effect of circumferential pressure variations. From this analysis, it is revealed that bearing stiffness has an optimum which, it is further shown, can be chosen through a proper selection of bearing design parameters, such as radial clearance, upstream resistor, and supply pressure. As the analysis is developed each assumption is experimentally verified. The final predictions of the analysis are also verified. It is felt that the analysis is sufficiently simple to allow comparison of many different bearing configurations, while sufficiently complete to compare very well against experimental measurements in all respects. A comparison is made between the recessed and nonrecessed bearing.

scholarly journals Floating Conditions of the Pads in Fluid Pivot Journal Bearing

2020 ◽  
Author(s):  
Vu Nguyen Tuyen ◽  
Weiguang Li
Keyword(s):  
Numerical Methods ◽  
External Force ◽  
Journal Bearing ◽  
Area Ratio ◽  
Squeeze Film ◽  
Eccentricity Ratio ◽  
Working Process ◽  
Ratio Increase ◽  
Equilibrium Conditions ◽  
Ratio Change

Abstract Fluid pivot journal bearing (FPJB) used on the ships was selected as the object of the study in this paper. The ability to form a squeeze film following the recess area ratio of the pad is systematically investigated under the condition that the preload factor and the eccentricity ratio change. Three positions of the load’s characteristic for the moving conditions of boats on the water are considered. Numerical methods are used to calculate the dynamic lubrication in bearing. Equilibrium conditions of force and moment are used to determine the floating conditions of the pads. The results show that during working process, the pad directly applied by the external force satisfies the floating condition, while the remaining pads are satisfied only when the preload factor and eccentricity ratio increase. In the early stages, the pad mostly float on one side. Floating condition curves are constructed as the basis for determining the optimal recess area.

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