29-07-2017, 10:35 AM
Machine element refers to an elementary component of a machine. These elements consist of three basic types:
1. structural components such as frame members, bearings, shafts, splines, fasteners, seals and lubricants,
2. Mechanisms controlling movement in various ways, such as gear trains, belt or chain drives, couplings, cam and follower systems, including brakes and clutches, and
3. Control components such as buttons, switches, indicators, sensors, actuators and computer controllers.
Although generally not considered a machine element, the shape, texture and color of the covers are an important part of a machine that provides a design and operating interface between the mechanical components of a machine and its users.
The elements of the machine are basic mechanical parts and features used as building blocks of most machines. Most are standardized to common sizes, but customs are also common for specialized applications.
The machine elements may be one-piece elements (such as threads or integral bearings) or may be discrete parts in themselves such as wheels, shafts, pulleys, rolling element bearings or gears. All simple machines can be described as machine elements, and many machine elements incorporate concepts of one or more simple machines. For example, a feed screw incorporates a screw thread, which is an inclined plane wrapped around a cylinder.
Many of the tasks of mechanical design, invention and engineering involve knowledge of various machine elements and a clever and creative combination of these elements into a component or assembly that fills a need (serves an application).