Ultra-precision bearings can achieve extreme accuracy of rotation, making them ideal for use in numerous applications across a variety of fields, including hard disk drives, roundness measuring machines and optical scanners. Ultraprecision Bearings provides a detailed review of the different types of bearing and their properties, as well as an analysis of the factors that influence motion error, stiffness and damping. Following an introduction to basic principles of motion error, each chapter of the book is then devoted to the basic principles and properties of a specific type of bearing: ball, hydrodynamic, aerodynamic, hydrostatic and aerostatic. The book concludes with a comparison of these types of bearing and their applications. - Provides practical information relating to precision bearing design and application - Provides an insight into the basic mechanisms that influence precision bearing performance - Written by an experienced and well respected bearing specialist
Frank Wardle is Managing Director of UPM Ltd - a research and development company specialising in Ultra Precision equipment. He has more than 30 years of practical experience in bearing research, initially with the rolling bearing companies Ransom, Hoffman and Pollard (RHP) and SKF and later with the air bearing manufacturer Loadpoint Ltd. Throughout this period he was not only responsible for research into ways of improving bearing performance, but also for developing new commercial bearing designs and some of the machinery used for their manufacture and testing.
Wardle
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Weitere Infos & Material
List of figures and tables
Figures
1.1 | Micro-milled upstand – 15 µm wide | 4 |
1.2 | Ultra precision bearing system | 6 |
1.3 | Effect of (a) synchronous, and (b) asynchronous motion error on surface form | 9 |
1.4 | Notation and components of motion error produced by rotating bearings | 10 |
1.5 | Measurement of ball bearing motion error | 11 |
1.6 | Total motion error | 12 |
1.7 | (a) Synchronous motion error; and (b) asynchronous motion error | 13 |
1.8 | (a) Fundamental error motion; and (b) residual synchronous error motion | 15 |
1.9 | Displacement time history and frequency analysis | 16 |
1.10 | Hypothetical bearing load-deflection characteristics | 19 |
1.11 | Notation and coordinate system used to define static stiffness | 20 |
1.12 | Deflections produced by radial load applied to preloaded ball bearing | 21 |
1.13 | Hydrodynamic bearing subject to radial load | 21 |
1.14 | Notation and coordinate system for linear bearings | 23 |
1.15 | Types of damping associated with bearings | 24 |
1.16 | Dynamic response of a bearing-shaft system | 26 |
1.17 | Effect of damping ratio on magnification factor | 27 |
1.18 | FEA of machine tool modes of vibration | 30 |
1.19 | Thermal distortion of machining spindle | 32 |
1.20 | Thermal model of bearing | 33 |
2.1 | (a) Single-row radial ball bearing; and (b) angular contact ball bearing | 38 |
2.2 | Sections available on precision angular contact bearings of nominally 50 mm pitch circle diameter | 40 |
2.3 | Example of single-row radial ball bearing arrangements | 41 |
2.4 | Popular angular contact ball bearing arrangements: (a) face–face; (b) back–back; (c) triple; and (d) quadruple bearing sets | 42 |
2.5 | Spring preloaded angular contact bearing arrangements | 43 |
2.6 | Example of shaft geometry and roughness parameters | 50 |
2.7 | Example of housing geometry and roughness parameters | 52 |
2.8 | Geometrical parameters | 54 |
2.11 | Loads and deflections for a single ball | 64 |
2.12 | Relative approach of inner and outer rings | 66 |
2.13 | Relative ring movements for spring loaded controlled alignment bearing subject to axial and radial loads | 70 |
2.14 | Axial load–deflection characteristics of 7006 angular contact ball bearing | 70 |
2.15 | Dependence of bearing stiffness on preload for a 7006 angular contact ball bearing | 71 |
2.16 | Comparison of spring and springbox preloaded bearing arrangements | 72 |
2.17 | The effect of mounting on the radial stiffness of a preloaded 7006 15-degree angular contact ball bearing | 73 |
2.18 | Spring preloaded angular contact bearing mounted in a linear bearing | 73 |
2.19 | Back–back angular contact bearing preloaded with spacers | 75 |
2.20 | Radial load–deflection relationships for 2007 spring preloaded and back–back mounted bearings subject to 50 N preload | 75 |
2.21 | Angular stiffness of spring preloaded and back–back mounted 7006 angular contact bearing | 76 |
2.22 | Effect of bearing speed on stiffness for a 7006 15-degree angular contact bearing subject to 200 N axial preload | 77 |
2.23 | Force equilibrium of ball in a high-speed bearing | 78 |
2.24 | Sources of damping associated with precision ball bearings | 80 |
2.25 | Model of ball–race contacts | 82 |
2.26 | Axial damping coefficient for preloaded 7006 15-degree angular contact bearing | 85 |
2.27 | Experimental and theoretical radial load deflection curves for preloaded 7210 angular contact bearing | 86 |
2.28 | Ball bearing with imperfections on ball, inner and outer ring surfaces | 90 |
2.29 | Relationship between dynamic force and displacement | 91 |
2.30 | Arrangement for measuring bearing vibration | 96 |
2.31 | Spectral analysis of outer raceway surface | 97 |
2.32 | Comparison of measured and theoretical axial acceleration spectra | 98 |
2.33 | Examples of the effect of axial preload on the low frequency vibration of a single-row radial ball bearing | 100 |
2.34 | Suggested minimum axial preload to prevent cage instability in grease lubricated single-row radial ball bearings | 101 |
2.35 | Ball load distribution in a radially loaded ball bearing | 102 |
2.36 | Variable compliance vibration produced by radially loaded bearing | 103 |
2.37 | Variable compliance produced by axially preloaded ball bearing | 104 |
2.38 | Dynamic component of variable compliance force due to misalignment | 104 |
2.39 | Lobing, waviness and roughness of rolling surfaces | 106 |
2.40 | Example of ball load variation due to 2-point lobing | 107 |
2.41 | Dynamic force produced by 2-point lobing in a preloaded ball bearing | 108 |
2.42 | Effect of one large ball on bearing motion error | 109 |
2.43 | Effect of random ball size variation on motion error | 109 |
2.44 | Example of axial dynamic force due to waviness | 110 |
2.45 | Example of radial dynamic force due to waviness | 110 |
2.46 | Surface roughness in relation to a ball–raceway... |