Machine Designers Reference

One-of-a-Kind Tool Speeds Mechanical Design Work Designers at all levels of experience need a handy, comprehensive reference that helps them get the job done faster... and better.Machine Designers ReferencebyJ. Marrsfulfills the need, and then some. This hardcover 716-page volume benefits from the author's 20 years of experience as a working mechanical designer. The result is 12 chapters organized in a very practical way (click the TOC button, above). This popular work is packed with essential charts and tables. Here are some of the features: Selection, sizing and tolerances for mechanical parts and assemblies Concise best practices for mechanical design, supported by charts and tables U.S. and metric units are presented for reader convenience Thorough representation of metric hardware Jennifer Marrs, P.E., is a mechanical design engineer. For two decades, her focus has been the design and analysis of high-speed assembly machines and related systems. She has also worked as a product designer, manufacturing engineer and forensic engineer. She is pictured here with the off-road vehicle she built by hand, a genuine labor of mechanical love. When Jennifer initially approached Industrial Press with her extraordinary idea forMachine Designers Reference, she said "I have an idea for a companion to Machinery's Handbook.... aToolboxthat contains items I've... squirreled away over my years of machine design. These are items that the working machine designer uses just about every day." Jennifer holds a BSME from Worcester Polytechnic Institute, an MSME from Northeastern University, and volunteers with the mechanical engineering programs at both WPI and Dartmouth College. She enjoys her successful consulting practice and is a licensed Professional Engineer throughout New England (clickhereto visit her website). She is also a registered U.S. patent agent. Her employers and clients include Gillette, Millipore, FujiFilm Dimatix, and Green Mountain Coffee Roasters. Mrs. Marrs is currently on the Executive Committee of her local ASME subsection and holds an international patent.EXCERPT from CHAPTER 10 BEARINGS 10.1 Plain Bearings Plain bearings provide sliding contact between two surfaces. The most common type of plain bearing is the sleeve bearing or bushing. Plain bearings are often chosen over rolling element bearings due to cost or space limitations. They are also more rigid and quieter in operation than rolling element bearings. The main disadvantages of plain bearings are their higher potential to wear (as compared to rolling element bearings) as well as their relative vulnerability to contaminants. This section serves as a general introduction to plain bearings, with a focus on sleeve bearings used in rotary motion applications with boundary lubrication conditions. Please consult the recommended resources for more information and calculation methods for other types of lubrication. Plain bearings used in linear motion applications are discussed in Section 10.3. Lubrication of Plain Bearings Plain bearings must be lubricated in order to have long life and low friction. There are four types of lubrication conditions under which plain bearings are run: hydrostatic lubrication (full film), hydrodynamic lubrication (full film), mixed film lubrication, and boundary lubrication (thin film). Full film lubrication occurs when the lubricant layer between surfaces is thick enough to prevent any surface contact. Boundary lubrication occurs when the lubricant layer is present but not thick enough to prevent contact between surfaces. A graph showing relative coefficients of friction for the different types of lubrication are shown in Figure 10-1. The horizontal axis is a function of lubricant viscosity (Z), journal speed (N), and bearing pressure (P). Recommended Resources * R. Mott, Machine Elements in Mechanical Design, 5th Ed., Pearson/Prentice Hall, Inc., Upper Saddle River, NJ, 2012 * R. L. Norton, Machine Design: An Integ...