Analysis of Dynamically Loaded Floating Bush Bearing With Flexible Shaft in Flexible Anisotropic Bearing Used in Textile Application

2008 ◽  
Author(s):  
D. C. Patel ◽  
D. P. Vakharia
Keyword(s):  
Journal Bearing ◽  
Reducing Power ◽  
Design Concept ◽  
Potential Contribution ◽  
Oil Whip ◽  
Excited Vibration ◽  
Textile Machine ◽  
Minimum Film Thickness ◽  
Dynamically Loaded ◽  
Bearing Design

A FLOATING bush bearing is a kind of bearing which has a thin bush floating freely between journal and fixed bush. In recent years considerable attention has been paid to the “vibration suppressing effect” of floating us bearing. It is reported that floating bush bearing are, if properly designed, effective in suppressing both resonant vibrations at the critical speed and self excited vibration call oil whip. This study deal with performance of dynamically loaded floating ring journal bearing and investigates their feasibility for two for one textile machine application. A mathematical model is developed and its analysis for performance of floating bush journal bearing with flexible shat in flexible anisotropic bearing is conducted. The potential contribution of the floating bush journal bearing design concept to reduce vibration is assessed and its compliance with current bearing durability criteria is evaluated. The result indicates that the adoption of floating bush design concept has potential for reducing power loss and vibration in two for one (TFO) textile machine bearing. It is shown that this can be accomplished without violating minimum film thickness constraints currently accepted as criteria for successful machine bearing operation.

Analysis of Dynamically Loaded Floating-Ring Bearings for Automotive Applications

1980 ◽  
Vol 102 (3) ◽  
pp. 271-276 ◽  
Author(s):  
Steve M. Rohde ◽  
Hazem A. Ezzat
Keyword(s):  
Reducing Power ◽  
Journal Bearings ◽  
Design Concept ◽  
Potential Contribution ◽  
Automotive Applications ◽  
Automotive Engine ◽  
Automotive Engines ◽  
Dynamically Loaded ◽  
Frictional Performance ◽  
Bearing Loads

This study deals with the frictional performance of dynamically loaded floating-ring journal bearings and investigates their feasibility for automotive applications. An analysis of the performance of floating-ring journal bearings in conducted. The bearing loads and speeds considered simulate those experienced in automotive engines. The potential contribution of the floating-ring design concept to reduced engine friction is assessed, and its compliance with current bearing durability criteria is evaluated. The results indicate that the adoption of the floating-ring design concept has the potential for reducing power loss in automotive engine bearings. It is shown that this can be accomplished without violating minimum film thickness constraints currently accepted as criteria for successful engine bearing operation.

Rapid and globally convergent method for dynamically loaded journal bearing design

1998 ◽  
Vol 212 (3) ◽  
pp. 207-214 ◽  
Author(s):  
H Hirani ◽  
K Athre ◽  
S Biswas
Keyword(s):  
Journal Bearing ◽  
Pressure Curve ◽  
Algebraic Equations ◽  
Connecting Rod ◽  
Main Bearing ◽  
Element Analysis ◽  
Globally Convergent ◽  
Dynamically Loaded ◽  
Convergent Method ◽  
Bearing Design

An approximate analytical pressure expression for dynamically loaded journal bearings is proposed. This approximation is applied to the solution of the finite journal bearing with a π-extent film. The starting and ending angular positions of the pressure curve are predicted by simple algebraic equations. The journal orbit is determined by treating it as an ‘inverse problem’ and evaluated by using the globally convergent Newton-Raphson method. To illustrate the validity of the present study, the Ruston and Hornsby big-end connecting rod bearing and an engine main bearing are analysed. The accuracy of the minimum film thickness and maximum film pressure values obtained by the proposed methodology is comparable to the more elaborate and time consuming finite element analysis, while the execution time is comparable to that required for the short bearing approximation.

Self-Excited Vibration of Statically Unloaded Pads in Tilting-Pad Journal Bearings

1983 ◽  
Vol 105 (3) ◽  
pp. 377-383 ◽  
Author(s):  
M. L. Adams ◽  
S. Payandeh
Keyword(s):  
Journal Bearing ◽  
Nonlinear Dynamic Analysis ◽  
Journal Bearings ◽  
Practical Significance ◽  
Oil Whip ◽  
Excited Vibration ◽  
Tilting Pad ◽  
Close Relationship ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

A time-transient nonlinear dynamic analysis is presented to study the motion of statically unloaded journal-bearing tilting pads. The major finding is that unloaded pads can exhibit a strong sub-synchronous self-excited vibration. The frequency of this periodic motion is somewhat below half the rotational speed and bears a close relationship to self-excited oil-whip vibration of rotors on lightly loaded non-tilting pad journal bearings. The identification of this type of self-excited pad vibration has practical significance to the solution of problems in applications involving damage to unloaded pads. A comprehensive parametric study is presented and shows which tilting-pad journal bearing parameters are significant to self-excited pad vibration and its elimination.

Dynamic Analysis of Tilting-Pad Journal Bearing—Influence of Pad Deformations

1994 ◽  
Vol 116 (3) ◽  
pp. 621-627 ◽  
Author(s):  
H. Desbordes ◽  
M. Fillon ◽  
C. Chan Hew Wai ◽  
J. Frene
Keyword(s):  
Film Thickness ◽  
Pressure Field ◽  
Journal Bearing ◽  
Maximum Pressure ◽  
Tilting Pad ◽  
Minimum Film Thickness ◽  
Dimensional Finite Element ◽  
The One ◽  
Tilting Pad Journal Bearing ◽  
Tilting Pad Journal Bearings

A theoretical nonlinear analysis of tilting-pad journal bearings is presented for small and large unbalance loads under isothermal conditions. The radial displacements of internal pad surface due to pressure field are determined by a two-dimensional finite element method in order to define the actual film thickness. The influence of pad deformations on the journal orbit, on the minimum film thickness and on the maximum pressure is studied. The effects of pad displacements are to decrease the minimum film thickness and to increase the maximum pressure. The orbit amplitude is also increased by 20 percent for the large unbalance load compared to the one obtained for rigid pad.

scholarly journals Pivoted-Pad Journal Gas Bearing Performance in Exploratory Operation of Brayton Cycle Turbocompressor

1968 ◽  
Vol 90 (4) ◽  
pp. 687-696 ◽  
Author(s):  
R. Y. Wong ◽  
W. L. Stewart ◽  
H. E. Rohlik
Keyword(s):  
Experimental Study ◽  
Journal Bearing ◽  
Inert Gas ◽  
Brayton Cycle ◽  
Ambient Conditions ◽  
Operating Characteristics ◽  
The Third ◽  
Loading Device ◽  
Bearing Design ◽  
Gas Bearing

This paper describes findings obtained to date in the area of journal gas bearings from an experimental study of a Brayton cycle turbocompressor designed for the requirements of a two-shaft 10-kw space power system. The journal bearing design utilizes three pads pivoted on conforming balls and sockets. Two of the pivots are rigidly mounted to the frame, and the third pivot is mounted to the frame through a low-spring-rate diaphragm. This paper describes the salient package and bearing design features and then presents the principal results obtained from testing the package in both a spin calibration rig and operation at design temperature conditions with an inert gas. The results discussed include (a) the successful use of a pneumatic loading device to vary pad load during operation, (b) the operating characteristics of the bearings as obtained over a range of pad loads and ambient conditions, (c) structural and dynamic behavior of the bearing-support system during design temperature operation and (d) a discussion of the wear characteristics of the conforming ball-and-socket pivot as obtained from the tests made to date.

Investigation of sustainability of lubricated journal bearing under relevant design parameters

2018 ◽  
Vol 70 (4) ◽  
pp. 789-804 ◽  
Author(s):  
M.M. Shahin ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Md. Arefin Kowser ◽  
Uttam Kumar Debnath ◽  
M.H. Monir
Keyword(s):  
Aspect Ratio ◽  
Elastic Strain ◽  
Journal Bearing ◽  
Design Parameters ◽  
Content Type ◽  
Computational Fluid Dynamics Cfd ◽  
Stress Formation ◽  
Bearing Design ◽  
The Stability ◽  
Bearing Friction

Purpose The purposes of the present study are to ensure higher sustainability of journal bearings under different applied loads and to observe bearing performances such as elastic strain, total deformation and stress formation. Design/methodology/approach A journal bearing test rig was used to determine the effect of the applied load on the bearing friction, film thickness, lubricant film pressure, etc. A steady-state analysis was performed to obtain the bearing performance. Findings An efficient aspect ratio (L/D) range was obtained to increase the durability or the stability of the bearing while the bearing is in the working condition by using SAE 5W-30 oil. The results from the study were compared with previous studies in which different types of oil and water, such as Newtonian fluid (NF), magnetorheological fluid (MRF) and nonmagnetorheological fluid (NMRF), were used as the lubricant. To ensure a preferable aspect ratio range (0.25-0.50), a computational fluid dynamics (CFD) analysis was conducted by ANSYS; the results show a lower elastic strain and deformation within the preferable aspect ratio (0.25-0.50) rather than a higher aspect ratio using the SAE 5W-30 oil. Originality/value It is expected that the findings of this study will contribute to the improvement of the bearing design and the bearing lubricating system.

Dynamic behaviors of a high-speed turbocharger rotor on elliptical floating-ring bearings

2019 ◽  
Vol 233 (12) ◽  
pp. 1785-1799 ◽  
Author(s):  
Congcong Zhang ◽  
Yongliang Wang ◽  
Rixiu Men ◽  
Hong He ◽  
Wei Chen
Keyword(s):  
High Speed ◽  
Reynolds Equation ◽  
Low Cost ◽  
Dynamic Behaviors ◽  
Oil Whirl ◽  
Excited Vibration ◽  
Dynamic Performances ◽  
Simulation Results ◽  
Bearing Design ◽  
Run Up

Floating-ring bearings are commonly used in automotive turbocharger applications due to their low cost and their suitability under extreme rotation speeds. This type of bearings, however, can become a source of noise due to oil whirl-induced sub-synchronous vibrations. The scope of this paper is to examine whether the concept of a floating-ring bearing with an elliptical clearance might be a solution to suppress sub-synchronous vibrations. A very time-efficient approximate solution for the Reynolds equation to the geometry of elliptical bearings is presented. The nonlinear dynamic behaviors of a turbocharger rotor supported by two concepts of elliptical floating-ring bearings are systematically investigated using run-up simulations. For the first concept of elliptical floating-ring bearings i.e. the outer bearing of the floating-ring bearing changed in the form of elliptical pattern (see Figure 1(b) in the article), some studies have pointed out that its steady-state and dynamic performances are superior to plain cylindrical floating-ring bearings but, the nonlinear run-up simulation results shown that this type of elliptical floating-ring bearings is not conducive to reduce the self-excited vibration levels. However, for the second type of elliptical floating-ring bearings i.e. both the inner and outer films of the floating-ring bearing changed in the form of elliptical pattern (see Figure 1(c) in the article), it is shown that the sub-synchronous vibrations have been considerably suppressed. Hence, the second noncircular floating-ring bearing design is an attractive measure to suppress self-excited vibrations.[Figure: see text]

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