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Introductioon to Tribology of Bearings B. C. Ma jumdar

Most books on Tribology are about research developments, although some deal with design and related practice. Relatively few are suitable for teaching programmes as a recommended text for a specific course. Any book dedicated to such a purpose is eagerly welcomed when it first appears and teachers of tribology will want to establish whether it fits the needs of their particular course. Like several of its distinguished predecessors, the book is strongly biased toward mechanical engineering aspects of tribology. This is to be expected since the subject matter, as the title implies, is about bearings and is based on lecture notes prepared for senior under- graduate and post-graduate engineering students in India. The material has been assembled from several books and other sources. The author's aim is to explain the theory and present an exposition of the fundamentals of fluid film bearings, rolling element bearings, and the friction and wear of metals.

There are sixteen chapters, most of which deal with the derivation of relevant theory and the development of appropriate solution procedures related to the design of bearings. The text is presented clearly and sensibly in a style which students should be able to use as a basis for their studies. The inevitable typographical errors should not hinder their efforts to grasp the essential fundamentals. There are very few worked examples and a some- what limited and unimaginative set of questions (about 25) are provided at the end of the book, but no answers are given. A chapter is devoted to an outline procedure related to the design of a fluid film bearing. There are also some advanced areas covered, such as surface roughness effects in bearings

Published by Y.P. Chopru for A.H. Wheeler, Allahabad, lndia, 1986, 327pp

and externally pressurised, including porous gas, bearings which are of special interest to the author.

Hydrodynamic theory is expounded in a logical sequence commencing with the development of the basic equations leading to a systematic treatment of idealised and finite bearings. Oil flow and thermal equilibrium considerations are dealt with simplistically before introducing a bearing design procedure. The mathematical relationships associated with squeeze film and instability behaviour are also presented. A review and development of elasto- hydrodynamic lubrication theory is followed by a section describing bail bearings and developments related to surface fatigue life behaviour.

The author believes that knowledge of theory alone is insufficient in the design of bearings. It must be supported by practical considerations like experience, judgement and the ability to analyse service requirements and to make a logical compromise where necessary. In view of this, it is unfor- tunate that although his treatment of the design-related aspects lays the basic foundations, it leaves a lot more to be done and very little guidance is provided for the student to follow. None of the current published design guide procedures are described or referenced. There is also no mention of the scope for using computer-aided procedures which are now fairly commonplace in British teaching programmes. A rather curious aspect of the layout is that while some chapters are quite heavily referenced, other chapters contain very few. This is particularly noticeable in the chapter dealing with bearing design which has just two references, the more recent of which was published in 1949.

Although several established reference works are listed, there are some notable omissions: for instance, Tribology Handbook, Dowson's 'History of Tribology' and the considerable con- tribution from Russian science on friction and wear receive no mention.

On the whole, it is a useful introduc- tory text which brings together in a single volume a collection of material gathered from several sources. As a basic textbook for mechanical engineering students studying tribology it may find a part to play, providing the purchase price is kept reasonably low.

g.J. Roylance University College of Swansea,

Swansea, Wales, UK

Machine Elements in Mechanical Design

Rober t L. M o t t

This book contains a large proportion of the information needed to design or select many commonly used machine elements, presented in a form useful for anyone from an engineering student to an experienced designer. Elements covered include shafts, couplings, gears, belts, chains, plain bearings, rolling bearings, clutches, brakes, and electric motors. Also covered are basic stress analysis and fatigue calculations, fits and tolerances, and bolted and welded joints.

For all the topics, design principles and requirements are described in detail, and design data and formulae are presented, often in graphical form. Both Imperial units and S.I. units are used, but with a bias towards Imperial units particularly in the worked examples and student exercises. Material properties, conversion factors, and many other useful data are con- tained in the appendices, and also throughout the book.

In all, very good value and highly recommended for anyone involved in machine design.

T.A. Polak Michael Neale Associates

Farnham, Surrey, UK

Published by Merrill, 1985, 600 pp, £15.95

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