Reciprocating

Reciprocating refers to actions or motions that occur in alternating directions or mutual exchange. In physics and engineering, reciprocating motion is motion that repeats in a back-and-forth, usually linear path along a straight line. This type of motion is a fundamental feature of many machines, including internal combustion engines, steam engines, and positive-displacement pumps. In such devices, a piston connected to a crankshaft by a connecting rod moves within a cylinder, converting linear motion to rotary motion or vice versa via a slider-crank mechanism. Reciprocating engines typically alternate strokes of intake, compression, power, and exhaust.

Reciprocating equipment is valued for delivering high force and precise displacement at relatively simple construction, but it can be less smooth and efficient than rotary solutions at high speeds due to inertial effects and sealing losses. Reciprocating components also include saw blades in reciprocating saws and piston pumps, where the back-and-forth action generates pressure to move fluids.

In a broader sense, reciprocating can describe actions that are mutual. In language, reciprocal actions describe interactions such as two parties performing actions for each other, often expressed with phrases like each other or one another. The term is also used in grammar and linguistics to denote mutual relations between participants.