A Miniature Linear Slide With Air Bearings and Its Implementation in a Mesoscale Precision Turning Machine

2007 ◽  
Author(s):  
Seung-Kook Ro ◽  
Byung-Sub Kim ◽  
Jong-Kweon Park
Keyword(s):  
Permanent Magnets ◽  
Thrust Force ◽  
Load Capacity ◽  
Linear Motor ◽  
Air Bearing ◽  
Air Bearings ◽  
Vertical Stiffness ◽  
Single Crystal Diamond ◽  
Micro Turning ◽  
Single Crystal Diamond Tool

In this paper, we propose a new miniature air-bearing stage with a moving-magnet slotless linear motor. This stage was developed to achieve the precise positioning required for submicron-level machining and miniaturization by introducing air bearings and a linear motor sufficient for mesoscale precision machine tools. The linear motor contained two permanent magnets and was designed to generate a preload force for the vertical air bearings and a thrust force for the stage movement. The characteristics of the air bearings, which used porous pads, were analyzed with numerical methods, and a magnetic circuit model was derived for the linear motor to calculate the required preload and thrust forces. A prototype of a single-axis miniature stage with dimensions of 120 × 120 × 50 mm3 was designed and fabricated, and its performance was examined, including its vertical stiffness, load capacity, thrust force, and positioning resolution. Two fabricated stages were then used for the X and Z-axes of a mesoscale micro-turning machine combined with an air-bearing spindle to investigate the effectiveness of the proposed system. A mirror surface was machined from an aluminum alloy with a single-crystal diamond tool.

A Meso-Scale Micro-Turning Machine With Modular Linear Air-Bearing Stages

2008 ◽  
Author(s):  
Seung-Kook Ro ◽  
Sung-Kweon Jang ◽  
Jong-Kwoen Park
Keyword(s):  
Permanent Magnets ◽  
Linear Motor ◽  
Diamond Turning ◽  
Depth Of Cut ◽  
Air Bearing ◽  
Air Bearings ◽  
Small Depth ◽  
Single Crystal Diamond ◽  
Micro Turning ◽  
Precision Machine Tools

In this paper, we describe the design, fabrication, and evaluation of a compact-sized diamond turning machine built with two air-bearing stages and a spindle. The two stages were developed to achieve the precise positioning required for submicron-level machining and miniaturization by introducing air bearings and a linear motor sufficient for mesoscale precision machine tools. The linear motor contained two permanent magnets and was designed to generate a preload force for the vertical air bearings and a thrust force for the stage movement. The size of the single-axis miniature stage was 120 × 120 × 50 mm3, and the footprint of the turning machine was 200 × 350 mm2, which is small enough for a tabletop. The positioning repeatability of the each linear axis was measured to be 0.05 μm, and the machining error and was evaluated by cutting various depths of an aluminum alloy mirror with a single-crystal diamond. The estimated workpiece–tool stiffness was lower than that with conventional ultraprecision machine, but a form error of less than 0.16 μm and a surface roughness (Rz) of 0.08 μm were achieved by the finishing cut using a small depth of cut. This reveals that miniaturized machines can be used successfully for precision machining of small precision parts.

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.

scholarly journals Performance Analysis of a Linear Motor with HTS Bulk Magnets for Driving a Prototype HTS Maglev Vehicle

2013 ◽  
Vol 416-417 ◽  
pp. 33-37
Author(s):  
You Guang Guo ◽  
Jian Xun Jin ◽  
Jian Guo Zhu ◽  
Hai Yan Lu
Keyword(s):  
Performance Analysis ◽  
Permanent Magnets ◽  
Thrust Force ◽  
Theoretical Calculations ◽  
Linear Motor ◽  
Field Analysis ◽  
Hts Bulk ◽  
Maglev Vehicle ◽  
Magnetic Field Analysis ◽  
Hts Maglev

This paper presents the performance analysis of a linear synchronous motor which employs high-temperature superconducting (HTS) bulk magnets on the mover and normal copper windings on the stator. The linear motor is designed to drive a prototype HTS maglev vehicle in which the mover is suspended by the levitation force between HTS bulks on the mover and permanent magnets on the ground. Finite element magnetic field analysis is conducted to calculate the major parameters of the linear motor and an equation is derived to calculate the electromagnetic thrust force. Theoretical calculations are verified by the measured results on the prototype.

Effect of Partial Texture on the Hydrodynamic Performance of Meso Scale Air Bearings for Mesoscale Turbo-Machines

2019 ◽  
Author(s):  
Nilesh Hingawe ◽  
Skylab Bhore
Keyword(s):  
Reynolds Equation ◽  
Promising Result ◽  
Load Capacity ◽  
Hydrodynamic Performance ◽  
Comsol Multiphysics ◽  
Air Bearing ◽  
Air Bearings ◽  
The Finite Element Method ◽  
Thin Film Model ◽  
Meso Scale

Abstract In this paper, the hydrodynamic performance of surface textured meso scale air bearing is evaluated. The effect of texture position is investigated for circular shaped texture. Partially textured zones are modeled along the circumferential direction of the bearing. For this, numerical simulation is carried out using COMSOL Multiphysics 5.2 software. The compressible Reynolds equation is solved using the finite element method for a thin film model. In comparison with plane bearing, the significant improvement in load capacity is observed for textured bearing. Full texturing has obtained 12.80% more load capacity than the plane bearing. Among different partial texture positions, the convergent zone (0°–180°) showed the most promising result. It has obtained 14.02% and 1.25% more load capacity than the plane and fully textured bearings. Moreover, the texture position in the bearing is found to be sensitive. However, surface texture at the outlet of active pressure zone is found to be ineffective for improving load capacity of the bearing.

Optimization of Herringbone Grooved Thrust Air Bearings for Maximum Load Capacity

2021 ◽  
pp. 1-25
Author(s):  
Yunluo Yu ◽  
Guang Pu ◽  
Tianchu Jiang ◽  
Kyle Jiang
Keyword(s):  
Load Capacity ◽  
Maximum Load ◽  
Optimization Method ◽  
Numerical Results ◽  
Air Bearing ◽  
The Novel ◽  
Air Bearings ◽  
Thrust Bearings ◽  
Herringbone Grooves

Abstract Many studies in herringbone grooved thrust bearings are focused on searching for the optimal groove parameters to improve the load capacity, but few of them adopting different grooves in different sections. In this study, a novel optimization method of herringbone grooved thrust air bearings is proposed for maximum load capacity by seeking the optimal groove parameters in each section of the bearing independently. An example of an optimized thrust air bearing is presented, and its performance is compared with a non-optimized bearing and a conventionally optimized bearing without dividing grooves into sections. The resultant herringbone grooves are found to have different parameters in the inner and outer sections, which is uncommon in existing grooves. Numerical results show that the novel bearing has a higher load capacity than the non-optimized reference bearing and conventionally optimized bearing. The study shows that the new design can increase load capacity by 30.77%, verified by experiments.

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.

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.

scholarly journals Truck Handling Stability Simulation and Comparison of Taper-Leaf and Multi-Leaf Spring Suspensions with the Same Vertical Stiffness

2020 ◽  
Vol 10 (4) ◽  
pp. 1293 ◽  
Author(s):  
Leilei Zhao ◽  
Yunshan Zhang ◽  
Yuewei Yu ◽  
Changcheng Zhou ◽  
Xiaohan Li ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Load Capacity ◽  
Lightweight Design ◽  
Steering Wheel ◽  
Leaf Spring ◽  
Slip Angle ◽  
Vertical Stiffness ◽  
Spring Suspension ◽  
Before And After ◽  
Stability Indexes

The lightweight design of trucks is of great importance to enhance the load capacity and reduce the production cost. As a result, the taper-leaf spring will gradually replace the multi-leaf spring to become the main elastic element of the suspension for trucks. To reveal the changes of the handling stability after the replacement, the simulations and comparison of the taper-leaf and the multi-leaf spring suspensions with the same vertical stiffness for trucks were conducted. Firstly, to ensure the same comfort of the truck before and after the replacement, an analytical method of replacing the multi-leaf spring with the taper-leaf spring was proposed. Secondly, the effectiveness of the method was verified by the stiffness tests based on a case study. Thirdly, the dynamic models of the taper-leaf spring and the multi-leaf spring with the same vertical stiffness are established and validated, respectively. Based on this, the dynamic models of the truck before and after the replacement were established and verified by the steady static circular test, respectively. Lastly, the handling stability indexes for the truck were compared by the simulations of the drift test, the ramp steer test, and the step steer test. The results show that the yaw rate of the truck almost does not change, the steering wheel moment decreases, the vehicle roll angle obviously increases, and the vehicle side slip angle slightly increases after the replacement. Thus, the truck with the taper-leaf spring suspension has better steering portability, however, its handling stability performs worse.

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