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.

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.

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.

Friction and Tribological Considerations for Nanometer Range Machining

2001 ◽  
Author(s):  
Som Chattopadhyay
Keyword(s):  
Mathematical Model ◽  
High Precision ◽  
Local Deformation ◽  
Experimental Results ◽  
Precision Machining ◽  
Complex Motion ◽  
Positioning Accuracy ◽  
Nanometer Range ◽  
Motion Characteristic ◽  
Low Speeds

Abstract Positioning accuracy within the range of nanometers is required for high precision machining applications. The implementation of such a range is difficult through the slides because of (a) irregular nature of friction at the slider-guideway interface, and (b) complex motion characteristic at very low speeds. The complexity arises due to the local deformation at the interface prior to breakaway, which is known as microdynamics. In this work prior experimental results exhibiting microdynamics have been appraised, and mathematical model developed to understand this behavior.

Störgrößenkompensation für Vorschubantriebe/Disturbance compensation for feed drives

2021 ◽  
Vol 111 (01-02) ◽  
pp. 82-87
Author(s):  
Felix Brenner ◽  
Armin Lechler ◽  
Alexander Verl
Keyword(s):  
Machine Tools ◽  
Position Control ◽  
Dynamic Compliance ◽  
High Accuracy ◽  
Considerable Improvement ◽  
Disturbance Compensation ◽  
Positioning Accuracy ◽  
Feed Drives ◽  
Modern Machine ◽  
Large Machine

Zahnstange-Ritzel-Antriebe werden überwiegend bei großen Werkzeugmaschinen eingesetzt und häufig mit indirekter Lageregelung betrieben. Hieraus resultiert eine geringe Positioniergenauigkeit und ein unzureichendes dynamisches Nachgiebigkeitsverhalten. Um den hohen Genauigkeitsanforderungen moderner Werkzeugmaschinen gerecht zu werden, wird in diesem Beitrag eine beschleunigungsbasierte Störgrößenkompensation vorgestellt. Experimentelle Ergebnisse belegen eine Verbesserung des Störverhaltens.   Rack-and-pinion drives are mainly used in large machine tools and controlled by indirect position control. This leads to low positioning accuracy as well as an insufficient dynamic compliance. To meet the high accuracy requirements of modern machine tools, this paper presents an acceleration-based disturbance compensation. Experimental results prove a considerable improvement of the disturbance behavior.

The Construction Basis of High-Precision Optical Range Finder GD-j1(l)

2018 ◽  
Vol 931 ◽  
pp. 681-686
Author(s):  
Hovsep S. Petrosyan ◽  
Yegisabeth H. Hayrapetyan ◽  
Hovnan A. Hunanyan
Keyword(s):  
High Precision ◽  
Linear Measurement ◽  
High Accuracy ◽  
Compensation Method ◽  
Interference Method ◽  
Modulation Method ◽  
Range Finder ◽  
Optical Range ◽  
Linear Measurements ◽  
Measurement Devices

The methods of construction of high-precision rangefinder on the modulation method, which will complement the means of linear measurements on the interference method, are considered. The linearly compensation method, which leads to the possibility of implementing range finders with an error of mφ=0.01 mm, is proposed as the basic constructions of extremely high accuracy linear measurement devices.

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.

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