Air bearings in high precision systems

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
I. Cracaoanu ◽  
F. Bremer
Keyword(s):  
Surface Topography ◽  
High Precision ◽  
Air Bearing ◽  
Test Results ◽  
Air Bearings ◽  
Bearing Surface ◽  
Operational Parameters ◽  
Low Friction ◽  
Air Supply ◽  
Precision System

In high precision system applications low friction levels between components are desirable. Moving heavy parts at high speeds and accelerations without friction is possible by using air bearings. The main failure ofthe air bearings is the wear phenomenon (modification of surface topography) that occurs due to crash into the counterpart when air supply is interrupted. The aim of this research is to investigate different types of air bearings for a large number of crashes using real operational parameters from the field: speed, acceleration, load and supply air pressure. The real crash phenomenon in a high precision machine hasbeen replicated using a test setup. During testing, evolution of air bearing surface topography and air bearing characteristics (gap and flow) after different number of crashes are investigated. Test results showthat some air bearings are not reaching the specified number of crashes due to large defects that occur on the bearing surface. Some specific relations were found between crash defects and parameters such asthe air gap size and the direct contact between opposing surfaces. The preferred type of air bearings shows good performance even above the maximum specified number of crashes. This behavior can be explainedby low friction level during crash tests between the opposing surfaces. The test results from this investigation produced a reliable candidate for air bearings in the high precision system application.

Experience and results obtained at the ESRF with high-precision air bearing motion systems

2011 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
P. Marion ◽  
L. Ducotte ◽  
M. Nicola ◽  
H. P. van der Kleij ◽  
L. Eybert ◽  
...  
Keyword(s):  
High Precision ◽  
High Accuracy ◽  
Air Bearing ◽  
Air Bearings ◽  
Positioning Accuracy ◽  
Point Of Interest ◽  
Air Film

In high-accuracy motion stages, the positioning accuracy at the point of interest is strongly influenced by guiding errors: for translation motions, straightness errors and angular errors (pitch, yaw and roll); for rotation motions, axial, radial and tilt errors. When air bearings are used for guiding, the air film averages out local irregularities of bearings surfaces, which helps reduce guiding errors considerably. Some results obtained with air bearing precision systems designed and manufactured by specialized companies and tested at ESRF are described below.

An Air Layer Modeling Approach for Air and Air/Vacuum Bearings

1997 ◽  
Vol 119 (3) ◽  
pp. 388-392
Author(s):  
J. M. Pitarresi ◽  
K. A. Haller
Keyword(s):  
Load Capacity ◽  
Load Resistance ◽  
High Load ◽  
Air Bearing ◽  
Air Bearings ◽  
Bearing Surface ◽  
Know How ◽  
Modeling Approach ◽  
Vibrational Characteristics ◽  
High Load Capacity

Air layer supported bearing pads, or “air bearings” as they are commonly called, are popular because of their high load capacity and low in-plane coefficient of friction, making them well suited for supporting moving, high accuracy manufacturing stages. Air/vacuum bearings enhance these capabilities by giving the bearing pad load resistance capacity in both the upward and downward directions. Consequently, it is desirable to know how to model the air layer between the bearing pad and the bearing surface. In this paper, a simple finite element modeling approach is presented for investigating the vibrational characteristics of an air layer supported bearing. It was found that by modeling the air layer as a bed of uniform springs who’s stiffness is determined by load-displacement tests of the bearing, a reasonable representation of the response can be obtained. For a bearing supported by air without vacuum, the dynamic response was very similar to that of a freely supported bearing. The addition of vacuum to an air bearing was found to significantly lower its fundamental frequency which could lead to unwanted resonance problems.

Air-bearing surface chemical modification for low-friction head–disk interface

2006 ◽  
Vol 13 (8-10) ◽  
pp. 811-816 ◽  
Author(s):  
Yuki Shimizu ◽  
Junguo Xu ◽  
Shozo Saegusa ◽  
Noritsugu Umehara
Keyword(s):  
Chemical Modification ◽  
Air Bearing ◽  
Surface Chemical ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Low Friction ◽  
Disk Interface ◽  
Surface Chemical Modification

Air Bearing Surface Design for Improving Efficiency of Thermomechanical Actuation

2007 ◽  
Author(s):  
Shuyu Zhang ◽  
Brian Strom ◽  
Sungchang Lee ◽  
Dongman Kim ◽  
George Tyndall ◽  
...  
Keyword(s):  
Dimensional Analysis ◽  
Numerical Solutions ◽  
Recording Media ◽  
Air Bearing ◽  
Air Bearings ◽  
Bearing Surface ◽  
Surface Design ◽  
Air Bearing Slider

Thermomechanical actuation (TMA) at the transducer region of the air bearing surface (ABS) protrudes the transducers toward the recording media, yet also results in greater air bearing slider lift. The ratio of these two effects is defined as the TMA efficiency. An expression based on dimensional analysis is introduced to describe the changes of air bearing forces due to TMA protrusion. A framework is proposed that facilitates optimization of ABS design for improved TMA efficiency. On the basis of the theory presented, several ABSs are designed to have different TMA efficiency. Numerical solutions of these air bearings respect to the protrusion shows agreement with the proposed theory.

Investigation of Air Bearings for Small High-Performance Aircraft Gas Turbines

1972 ◽  
Vol 94 (4) ◽  
pp. 294-302
Author(s):  
P. W. Curwen ◽  
W. E. Young ◽  
R. G. Furgurson
Keyword(s):  
Performance Studies ◽  
Gas Turbines ◽  
High Performance ◽  
Air Bearing ◽  
Test Results ◽  
Air Bearings ◽  
Propulsion Systems ◽  
And Performance ◽  
Turboshaft Engine ◽  
Engine Start

High temperatures and rotative speeds of future U. S. Army aircraft propulsion systems will impose increasingly severe operating requirements on oil-lubricated engine bearings and associated seals. Accordingly, air-lubricated bearings are being investigated as a possible approach to alleviating the lubrication problems. This paper presents the results of design and performance studies, as well as bearing component tests, relative to applying air bearings to a two-shaft, 3.5-lb/sec turboshaft engine. The test results verify that air bearings can carry the maximum loads imposed by flight and landing conditions, and can survive the sliding contacts associated with 15,000 engine start/stop cycles. Incentives for pursuing the air-bearing approach are identified, as are also the development and problem areas.

Fluorine-ion-implanted air-bearing surface for low-friction head–disk interface

2009 ◽  
Vol 16 (1-2) ◽  
pp. 293-299 ◽  
Author(s):  
Yuki Shimizu ◽  
Noritsugu Umehara ◽  
Junguo Xu
Keyword(s):  
Air Bearing ◽  
Head Disk Interface ◽  
Bearing Surface ◽  
Low Friction ◽  
Disk Interface ◽  
Ion Implanted

scholarly journals Dimensionless Analysis on the Characteristics of Pneumatic Booster Valve with Energy Recovery

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Fan Yang ◽  
Kotaro Tadano ◽  
Gangyan Li ◽  
Toshiharu Kagawa
Keyword(s):  
Mathematical Model ◽  
Energy Efficiency ◽  
Energy Recovery ◽  
Operational Parameters ◽  
Local Pressure ◽  
Air Power ◽  
Improve Energy Efficiency ◽  
Dimensionless Analysis ◽  
Air Supply ◽  
Save Energy

Factories are increasingly reducing their air supply pressures in order to save energy. Hence, there is a growing demand for pneumatic booster valves to overcome the local pressure deficits in modern pneumatic systems. To further improve energy efficiency, a new type of booster valve with energy recovery (BVER) is proposed. The BVER principle is presented in detail, and a dimensionless mathematical model is established based on flow rate, gas state, and energy conservation. The mathematics model was transformed into a dimensionless model by accurately selecting the reference values. Subsequently the dimensionless characteristics of BVER were found. BVER energy efficiency is calculated based on air power. The boost ratio is found to be mainly affected by the operational parameters. Among the structural ones, the recovery/boost chamber area ratio and the sonic conductance of the chambers are the most influential. The boost ratio improves by 15%–25% compared to that of a booster valve without an energy recovery chamber. The efficiency increases by 5%–10% depending on the supply pressure. A mathematical model is validated by experiment, and this research provides a reference for booster valve optimisation and energy saving.

Design of Low-Speed Spindle Running on Air Bearings Used on Rotary Viscometer

2012 ◽  
Vol 531-532 ◽  
pp. 751-754
Author(s):  
Ying Xue Yao ◽  
Hong Bo Wang ◽  
Liang Zhou
Keyword(s):  
Rotating Cylinder ◽  
Air Bearing ◽  
Air Bearings ◽  
Low Speed ◽  
Operation Process ◽  
Velocity Attenuation ◽  
Rotary Viscometer

A low-speed spindle running on air bearings is presented, it is used on rotary viscometer based on velocity attenuation of rotating cylinder. Principle of spindle is introduced, it is composed of a low speed motor and an air bearing. The low speed motor is a coupling of two motors. Design of the spindle shows the structure of it. Materials of the spindle are selected. The spindle is machined and operation process of it shows it is suitable for driving part of rotary viscometer based on velocity attenuation of rotating cylinder.

High-precision system for certifying and qualifying liquid metering pumps

1993 ◽  
Vol 36 (4) ◽  
pp. 469-471
Author(s):  
E. A. Khatskevich
Keyword(s):  
High Precision ◽  
Precision System
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