Experimental Investigation of Static Characteristics of a Vacuum Preloaded Aerostatic Bearing

2011 ◽  
Vol 311-313 ◽  
pp. 1012-1016 ◽  
Author(s):  
Shan Shan Liu ◽  
Han Chen ◽  
Xue Dong Chen
Keyword(s):  
Analytical Model ◽  
Carrying Capacity ◽  
Vacuum Pressure ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Aerostatic Bearing ◽  
Supply Pressure ◽  
Air Supply ◽  
Load Carrying ◽  
Bearing Stiffness

A vacuum preloaded circular aerostatic bearing was designed and its static characteristics were investigated experimentally. The load carrying capacity and air film thickness of the bearing were measured for different air supply pressure and vacuum pressure values. An orthogonal table was constructed to optimize the experimental measurement. Regression analysis was performed on the experimental results to obtain an analytical model of the bearing stiffness as a function of the load carrying capacity, air supply pressure and vacuum pressure. Accuracy of this analytical model in predicting static characteristics of the aerostatic bearing was validated by comparison with experimental data, and influences of the functioning parameters were also discussed.

Static characteristics of misaligned multiple axial groove water-lubricated bearing in the turbulent regime

2016 ◽  
Vol 231 (3) ◽  
pp. 385-398 ◽  
Author(s):  
Ravindra Mallya ◽  
Satish B Shenoy ◽  
Raghuvir Pai
Keyword(s):  
Reynolds Number ◽  
Friction Coefficient ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Load Capacity ◽  
Turbulent Regime ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Load Carrying ◽  
Turbulence Effects

The static characteristics of misaligned three-axial water-lubricated journal bearing in the turbulent regime are analyzed for groove angles 36° and 18°. Ng and Pan’s turbulence model is applied to study the turbulence effects in the journal bearing. The static parameters such as load-carrying capacity, friction coefficient, and side leakage are found for different degree of misalignment (DM). The change in flow regime of the lubricant from laminar to turbulent and the increase in misalignment, improved the load capacity of the bearing. For lightly loaded bearings, the friction coefficient of the bearing increased with the increase in Reynolds number.

Performance characteristics of rectangular aerostatic thrust bearing by conformal mapping

2018 ◽  
Vol 70 (8) ◽  
pp. 1457-1475
Author(s):  
Shang-Han Gao ◽  
Sheng-Long Nong
Keyword(s):  
Conformal Mapping ◽  
Pressure Distribution ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Performance Characteristics ◽  
Load Carrying Capacity ◽  
Möbius Transform ◽  
Content Type ◽  
Air Supply ◽  
Load Carrying

Purpose This paper aims to analyze the pressure distribution of rectangular aerostatic thrust bearing with a single air supply inlet using the complex potential theory and conformal mapping. Design/methodology/approach The Möbius transform is used to map the interior of a rectangle onto the interior of a unit circle, from which the pressure distribution and load carrying capacity are obtained. The calculation results are verified by finite difference method. Findings The constructed Möbius formula is very effective for the performance characteristics researches for the rectangular thrust bearing with a single air supply inlet. In addition, it is also noted that to obtain the optimized load carrying capacity, the square thrust bearing can be adopted. Originality/value The Möbius transform is found suitable to describe the pressure distribution of the rectangular thrust bearing with a single air supply inlet.

Elastic Deformation Effects on the Thermo-Hydrodynamic Aspect of Porous Journal Bearings

2014 ◽  
Vol 353 ◽  
pp. 275-279
Author(s):  
S. Boubendir ◽  
Salah Larbi ◽  
R. Bennacer
Keyword(s):  
Elastic Deformation ◽  
Carrying Capacity ◽  
Reynolds Equation ◽  
Maximum Pressure ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Governing Equations ◽  
Load Carrying ◽  
Variation Parameter ◽  
Viscosity Variation

In this paper, the effects of porous bush elastic deformation on the static characteristics of finite porous journal bearing are investigated using Darcy’s law. The modified Reynolds equation applied to thermo-hydrodynamic problems is modified by considering the viscosity variation along the film thickness. The film pressure distribution and other characteristics such as the load carrying capacity and attitude angle are obtained by solving the governing equations numerically. Obtained results showed that deformation is considerable in the maximum pressure zone, and the elastic deformation will decrease the load carrying capacity. The viscosity variation parameter tends also to decrease the load carrying capacity.

The Effects of Fluid Inertia Forces on the Static Characteristics of Sector-Shaped, High-Speed Thrust Bearings in Turbulent Flow Regime

1989 ◽  
Vol 111 (3) ◽  
pp. 406-412 ◽  
Author(s):  
H. Hashimoto
Keyword(s):  
Carrying Capacity ◽  
High Speed ◽  
Experimental Results ◽  
Polar Coordinates ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Fluid Inertia ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Inertia Forces

This paper describes a study on the performance characteristics of sector-shaped, high-speed thrust bearings subjected to the effects of both turbulence and fluid inertia forces. The basic lubrication equations are derived by integrating the momentum and continuity equations in the polar coordinates including the full inertia terms throughout the film thickness; and a numerical calculation technique combining the control volume integration and the Newton-Raphson linearization method is applied to solve the equations. The static characteristics such as the load carrying capacity and the pressure center are calculated for various values of pad extent angle and inner-to-outer radius ratio of a pad. The theoretical results of the load carrying capacity are compared with the experimental results. It was found that the fluid inertia forces have significant effects on the static characteristics of the bearings. Good agreement was obtained between theoretical and experimental results.

Performance Study of Aerostatic Bearings with Arrayed Microhole Restrictors

2011 ◽  
Vol 311-313 ◽  
pp. 386-391
Author(s):  
Peng Li ◽  
Han Chen ◽  
Xue Dong Chen
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Aerostatic Bearing ◽  
Performance Study ◽  
Load Carrying ◽  
Ultra Precision ◽  
New Type ◽  
Computational Fluid Dynamics Cfd ◽  
Aerostatic Bearings ◽  
Micro Vibration

Micro-vibration of aerostatic bearings has been the bottleneck in the improvement of the moving and positioning accuracy of ultra-precision fabrication and metrology equipments. In this study, a new type of aerostatic bearing restrictor has been proposed. The prototype of arrayed microhole restrictor, instead of the conventional single hole restrictor was developed with the aim of reducing the harmful micro-vibration of aerostatic bearings. Computational fluid dynamics (CFD) was employed to numerically calculate the air flow field. It is found that the employment of arrayed microhole restrictors can reduce the amount of micro-vibration while maintain the load carrying capacity and stiffness of the aerostatic bearing. Experimental measurement of the micro-vibration confirms the effectiveness of this new type of restrictor.

scholarly journals Bearing Capacity of Interfered Adjacent Strip Footings on Granular Bed Overlying Soft Clay: An Analytical Approach

2021 ◽  
Vol 7 (7) ◽  
pp. 1244-1263
Author(s):  
R. Shivashankar ◽  
S. Anaswara
Keyword(s):  
Bearing Capacity ◽  
Analytical Model ◽  
Carrying Capacity ◽  
Soft Clay ◽  
Punching Shear ◽  
Load Carrying Capacity ◽  
Granular Bed ◽  
Shear Model ◽  
Load Carrying ◽  
Strip Footings

In the present paper, the interference effects on bearing capacity of two and three closely spaced strip footings resting on granular bed overlying clay are being studied. A simple analytical model is proposed to predict the load-carrying capacity and the interference factor of an interfered footing, when adjacent strip footings are optimally placed on the surface of a Granular Bed (GB) overlying clay and both the footings are simultaneously loaded. A punching shear failure mechanism is envisaged in the analytical model. The load-carrying capacity of the footing is taken as the sum of total shearing resistances along the two vertical planes through the edges of the strip footing in the upper granular layer and the load-carrying capacity of the soft clay beneath the GB. Insights gained from finite element simulations are used to develop the new modified punching shear model for interfering footing. Bearing capacity can be easily calculated by using the proposed punching shear model for interfering footing. The analytical model is validated with numerical analyses and previous experimental results and found to be in reasonably good agreement. The influence of different parameters such as granular bed thickness, width of footing, number of footings are carried out in this study. Doi: 10.28991/cej-2021-03091723 Full Text: PDF

Self-Compensated Precision Hydrostatic Rotary Bearing

2013 ◽  
Vol 662 ◽  
pp. 674-677
Author(s):  
Xiao Bo Zuo ◽  
Jian Min Wang ◽  
Zi Qiang Yin ◽  
Sheng Yi Li
Keyword(s):  
Fluid Flow ◽  
Carrying Capacity ◽  
Radial Direction ◽  
Axial Direction ◽  
Load Carrying Capacity ◽  
Hydrostatic Bearing ◽  
Supply Pressure ◽  
Load Carrying ◽  
Network Method ◽  
Precision Machines

A self-compensated hydrostatic rotary bearing is designed and manufactured. The bearing is modeled by fluid flow network method, and simulations are performed to predict the load carrying capacity. A hydrostatic bearing prototype has been tested and results show that it can achieve a stiffness of 120N/μm in radial direction and 220N/μm in axial direction under a supply pressure of 1 MPa, and its motion accuracy is 0.3μm. The designed bearing is suitable to be used in precision machines.

Minimised Gear Lubrication by a Minimum Oil/Air Flow Rate

2007 ◽  
Author(s):  
Bernd-Robert Ho¨hn ◽  
Klaus Michaelis ◽  
Hans-Philipp Otto
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Load Carrying Capacity ◽  
Air Supply ◽  
Load Carrying ◽  
Air Lubrication ◽  
Oil Flow ◽  
Application Potential ◽  
Supply Systems

The objectives of the research project were to investigate the limits concerning possible reduction of lubricant quantity in gears without detrimental influence on the load carrying capacity. The investigations covered the influence of the oil level in dip lubricated systems as well as the oil flow rate in spray lubricated systems namely oil-air supply systems on power loss, heat generation and load carrying capacity. The load carrying capacity in terms of characteristic gear failure modes was determined and was compared to the results using conventional lubricant volumes with dip lubrication. Therefore in back-to-back gear tests the parameters speed, load and oil quantity were varied for examination of the four main gear flank damages: scuffing, wear, pitting and micropitting. The investigations showed the application potential of oil/air lubrication also for heavy duty transmissions nevertheless there exists a natural limitation for lowering the oil quantity in transmissions without detrimental influence on the load carrying capacity.

Incompressible and Analytical Study on a Basic Model of Out-Pump Type Complex Journal Gas Bearings

2008 ◽  
Vol 381-382 ◽  
pp. 153-156
Author(s):  
S. Yao ◽  
S.M. Barrans ◽  
L. Blunt
Keyword(s):  
Analytical Model ◽  
Carrying Capacity ◽  
Analytical Study ◽  
Coupling Mechanism ◽  
Load Carrying Capacity ◽  
Basic Model ◽  
Type Complex ◽  
Load Carrying ◽  
Set Up ◽  
Gas Bearing

A basic analytical model of the out-pump type complex journal gas bearing is set up to investigate the coupling mechanism between aerodynamics and aerostatics in a complex gas bearing and to improve its performance, under incompressible conditions. The analytical model shows that the load-carrying capacity function is composed of five items. Apparently, there is both pressure and structure coupling between aerodynamics and aerostatics; identically, the surface feature function is positive; and when the groove distribution coefficient is 0.30, it is approximately maximum.

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