slider crank

A slider-crank mechanism is a mechanical system that converts rotary motion into linear motion, or vice versa. It is one of the most fundamental and widely used mechanisms in engineering, especially in engines and pumps.

The slider-crank consists of four main components:

Crank – A rotating arm connected to a rotating shaft.

Connecting Rod – A rigid link that connects the crank to the slider.

Slider (or Piston) – A component that moves back and forth in a straight line.

Frame – The fixed structure that supports the mechanism.

When the crank rotates, it pushes and pulls the connecting rod, causing the slider to move in a straight reciprocating motion. This motion conversion makes the slider-crank mechanism essential in machines such as the internal combustion engine. For example, in a car engine, the piston moves linearly due to combustion pressure, which turns the crankshaft and produces rotational motion to drive the wheels.

Slider-crank mechanisms are commonly found in:

Automobile engines

Steam engines

Reciprocating compressors

Pumps

The mechanism is valued for its simplicity, reliability, and efficiency in transferring motion and force. Because of these characteristics, the slider-crank remains one of the most important mechanisms in mechanical engineering applications.