A pulley, also called a sheave or a drum is a mechanism composed of a wheel on an axle or shaft,generally having groove between two flanges around its circumference. Pulley systems are used to lift large masses onto tall heights. The pulley system consists of one or more pulleys and a rope or a cable.
Coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. Couplings do not normally allow disconnection of shafts during operation. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment or end movement or both. By careful selection, installation and maintenance of couplings, substantial savings can be made in reduced maintenance costs and downtime. Its applications are varied like in surgical devices, patient monitors, medical beds, analytical equipment, food & beverage, electronic cooling, fuel cells, ink delivery & printing, semiconductor process.
A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical ratio through a gear ratio. Geared devices can change the speed, magnitude, and direction of a power source.
Chains are usually made in one of two styles, according to their intended use; these are designed for lifting, such as when used with a hoist for pulling or for securing, such as with a bicycle lock have links that are torus shaped, which makes the chain flexibles.
A sprocket is a profiled wheel with teeth that meshes with a chain, track or other perforated or indented material. Sprockets are used in bicycles, motorcycles, cars, tracked vehicles,etc either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. Sprockets typically do not have a flange. Some sprockets used with timing belts to keep the timing belt centered. These have wide varied applications in cement plants, sugar mills, sponge iron plants, fertilizer plants, thermal power station, mineral plants and other manufacturing industries.