ABSTRACT
Prime movers, such as steam, gas, and hydraulic turbines, are machines which deliver mechanical energy in the form of work while extracting mechanical and/or thermal energy from a pressurized steam, gas, or liquid working fluid. Pumps and compressors, on the other hand, are machines which do the reverse (i.e., they absorb work in order to effect a rise of mechanical and/ or thermal energy in a fluid handled by them). Drill presses, lathes, and milling machines are examples of machine tools which require a work input to enable them to accomplish work in removing portions of metal or other material from unshaped stock. Still another class of machines (e.g., speed reducers) simply transfer power between shafts operating at different speeds. In general, there are many kinds of machines, and all of them are devices which transfer energy. Because machines always involve work and energy, terms like force, torque, work, and power are used to discuss their design and performance, and the analysis of the forces on and motions of their parts is essential to understanding their operation. Force and motion analysis of machine components is the major emphasis of this handbook, and because this kind of analysis, applied to a machine, is an integral part of the process of design, an overview of machine design is presented first.
