Design of Pivoted-Pad Journal Bearings

1969 ◽  
Vol 91 (1) ◽  
pp. 87-103 ◽  
Author(s):  
R. C. Elwell ◽  
J. A. Findlay
Keyword(s):  
Numerical Solution ◽  
Incompressible Flow ◽  
Digital Computer ◽  
Reynolds Equation ◽  
Load Capacity ◽  
Journal Bearings ◽  
Numerical Results ◽  
Load Direction ◽  
Numerical Examples ◽  
Calculated Load

Calculated load capacity and friction for complete pivoted-pad journal bearings are presented, for use in design computations. Dimensionless numerical results are given for the following variations in bearing geometry: 3 and 5 pads, L/D ratios of 1/2 to 1, pivot locations of 40, 50, and 60 percent, on pivot and between pivot loading, and ratios of “assembled” to “ground” clearance of 0.6, 0.8, and 1.0. The numerical results are an extension of the work of Castelli, et al., reference [1],1 and were generated in the same manner i.e., numerical solution of Reynolds’ equation by digital computer. Laminar, incompressible flow, and subambient pressures in diverging portions of the films were assumed. Illustrative numerical examples are included and significant conclusions with respect to major variables (L/D ratio, number of pads, clearances, pivot location, load direction) are drawn from the range of data produced.

Empirical Treatment of Hydrodynamic Journal Bearing Performance in the Superlaminar Regime

1970 ◽  
Vol 12 (2) ◽  
pp. 116-122 ◽  
Author(s):  
H. F. Black
Keyword(s):  
Reynolds Number ◽  
Field Equation ◽  
Experimental Work ◽  
Reynolds Equation ◽  
Pressure Field ◽  
Journal Bearing ◽  
Load Capacity ◽  
Journal Bearings ◽  
Theoretical Treatment ◽  
Hydrodynamic Journal Bearing

The application of a perturbation in terms of simple correlations for friction in turbulent Couette and ‘screw’ flows, together with a further empirical assumption consonant with the experimental work of Smith and Fuller (1), leads to a pressure field equation identical in form with the Reynolds equation. The load capacity of journal bearings throughout most of the superlaminar range may be represented by a single curve, and existing laminar solutions may be applied with the parameters modified by Reynolds number. The theory is compared with published experimental results, and with the most successful theoretical treatment (4). The correlations obtained confirm the adequacy of the theory to predict performance in the superlaminar régime.

A Numerical Solution for the Incompressible Hybrid Journal Bearing With Cavitation

1969 ◽  
Vol 91 (3) ◽  
pp. 508-515 ◽  
Author(s):  
Stanley Heller ◽  
Wilbur Shapiro
Keyword(s):  
Vapor Pressure ◽  
Pressure Gradient ◽  
Numerical Solution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Supply Circuit ◽  
Hydrodynamic Bearing

A numerical solution is presented for determining performance for hybrid journal bearings with arbitrary clearance distribution and cavitation. Regions of cavitation are determined by solution of the incompressible Reynolds’ equation. The pressures in the cavitated regions are immediately adjusted to a specified vapor pressure with zero pressure gradient. The continuity of mass equation permits coupling the influence of the external supply circuit and the methods of recess compensation to the Reynolds’ equation. Results are presented for geometrically similar hydrodynamic, hydrostatic, and hybrid bearings. Favorable comparisons are made with previously published results for the hydrodynamic bearing.

scholarly journals Mathematical Model and Analysis of the Water-Lubricated Hydrostatic Journal Bearings considering the Translational and Tilting Motions

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Hui-Hui Feng ◽  
Chun-Dong Xu ◽  
Jie Wan
Keyword(s):  
High Speed ◽  
Reynolds Equation ◽  
Load Capacity ◽  
Journal Bearings ◽  
Linear Perturbation ◽  
Eccentricity Ratio ◽  
Dynamic Coefficients ◽  
Pressure Fields ◽  
Dynamic Performances ◽  
Rotary Speed

The water-lubricated bearings have been paid attention for their advantages to reduce the power loss and temperature rise and increase load capacity at high speed. To fully study the complete dynamic coefficients of two water-lubricated, hydrostatic journal bearings used to support a rigid rotor, a four-degree-of-freedom model considering the translational and tilting motion is presented. The effects of tilting ratio, rotary speed, and eccentricity ratio on the static and dynamic performances of the bearings are investigated. The bulk turbulent Reynolds equation is adopted. The finite difference method and a linear perturbation method are used to calculate the zeroth- and first-order pressure fields to obtain the static and dynamic coefficients. The results suggest that when the tilting ratio is smaller than 0.4 or the eccentricity ratio is smaller than 0.1, the static and dynamic characteristics are relatively insensitive to the tilting and eccentricity ratios; however, for larger tilting or eccentricity ratios, the tilting and eccentric effects should be fully considered. Meanwhile, the rotary speed significantly affects the performance of the hydrostatic, water-lubricated bearings.

Non-Newtonian Micropolar Fluid Squeeze Film Between Conical Plates

2012 ◽  
Vol 67 (6-7) ◽  
pp. 333-337 ◽  
Author(s):  
Jaw-Ren Lin ◽  
Chia-Chuan Kuo ◽  
Won-Hsion Liao ◽  
Ching-Been Yang
Keyword(s):  
Micropolar Fluid ◽  
Reynolds Equation ◽  
Fluid Model ◽  
Load Capacity ◽  
Numerical Results ◽  
Squeeze Film ◽  
Micropolar Fluids ◽  
Newtonian Case ◽  
Film Characteristics ◽  
Film Lubrication

By applying the micropolar fluid model of Eringen (J. Math. Mech. 16, 1 (1966) and Int. J. Mech. Sci. 31, 605 (1993)), the squeeze film lubrication problems between conical plates are extended in the present paper. A non-Newtonian modified Reynolds equation is derived and applied to obtain the solution of squeeze film characteristics. Comparing with the traditional Newtonian case, the non-Newtonian effects of micropolar fluids are found to enhance the load capacity and lengthen the approaching time of conical plates. Some numerical results are also provided in tables for engineer applications

A Contribution to the Analysis of the Thermo-Hydrodynamic Lubrication of Porous Self-Lubricating Journal Bearings

2010 ◽  
Vol 297-301 ◽  
pp. 618-623 ◽  
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
Rachid Bennacer
Keyword(s):  
Thermal Effects ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Porous Matrix ◽  
Journal Bearings ◽  
Governing Equations ◽  
Hydrodynamic Analysis ◽  
Result Show

In this work the influence of thermal effects on the performance of a finite porous journal bearing has been investigated using a thermo-hydrodynamic analysis. The Reynolds equation of thin viscous films is modified taking into account the oil leakage into the porous matrix, by applying Darcy’s law to determine the fluid flow in the porous media. The governing equations were solved numerically using the finite difference approach. Obtained result show a reduction in the performance of journal bearings when the thermal effects are accounted for and, this reduction is greater when the load capacity is significant.

Analysis of Noncircular Gas Journal Bearings

1975 ◽  
Vol 97 (4) ◽  
pp. 616-623 ◽  
Author(s):  
O. Pinkus
Keyword(s):  
Reynolds Equation ◽  
Load Capacity ◽  
Full Range ◽  
Maximum Load ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Significant Advance ◽  
Arbitrary Direction ◽  
Isothermal Conditions ◽  
Load Vector

The compressible Reynolds Equation under isothermal conditions was solved for finite elliptical and 3-lobe bearings with the load vector acting in any arbitrary direction over the full range of 360 deg. Envelopes of minimum and maximum eccentricity for a given set of operating conditions are provided, the first to yield maximum load capacity, and the second to assist stability by a choice of the highest possible ε. Some values of the spring and damping forces are also given and it is shown that in comparison with conventional bearings, the non-circular designs offer a significant advance in stiffness, particularly for low ε, when instability is most often encountered.

The Load Capacity of Short Journal Bearings With Oscillating Effective Speed

1964 ◽  
Vol 86 (2) ◽  
pp. 348-353 ◽  
Author(s):  
B. K. Gupta ◽  
R. M. Phelan
Keyword(s):  
Significant Contribution ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Solutions ◽  
Load Capacity ◽  
Journal Bearings ◽  
Squeeze Film ◽  
Major Conclusion ◽  
Angular Velocities ◽  
Effective Speed

The development of the Reynolds equation for the general case of dynamically loaded journal bearings is extended to include the concept of an effective speed that combines in one term the angular velocities of the journal, bearing, and load. Numerical solutions for the short-bearing approximation are presented for the case of an oscillating effective speed and a load that is constant or varying sinusoidally. Results are compared with available experimental data. The major conclusion is that for those cases involving an oscillating effective speed and a reversing load, the only significant contribution to load capacity comes from the squeeze film and the wedge film can safely be ignored when designing such bearings.

Unsteady Loads on Supercavitating Hydrofoils of Finite Span

1966 ◽  
Vol 10 (02) ◽  
pp. 107-118
Author(s):  
Sheila Evans Widnall
Keyword(s):  
Numerical Solution ◽  
Numerical Method ◽  
Integral Equations ◽  
Digital Computer ◽  
High Speed ◽  
Three Dimensional ◽  
Numerical Results ◽  
Oscillatory Motion ◽  
Surface Theory ◽  
Finite Span

Linearized three-dimensional lifting-surface theory is derived for a supercavitating hydrofoil with finite span in steady or oscillatory motion through an infinite fluid. The resulting coupled-integral equations are solved on a high-speed digital computer using a numerical method of assumed modes similar to that used for fully wetted surfaces. Numerical results for lift and moment for both steady and oscillating foils are compared with other theories and experiments. Results of these calculations indicate that this numerical solution gives an efficient and accurate prediction of loads on a supercavitating foil.

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