Reciprocating motion is the repetitive up-and-down or back-and-forth movement of an object. Reciprocating motion and vibratory motion are very closely related to each other, but there is a small exception that reciprocating motion necessarily involves up-and-down or back-and-forth linear motion. For example, sewing machine needle, piston pumps, etc.
Examples of Reciprocating Motion
1. Sewing Machine Needle
The needle of a tailoring machine makes use of reciprocating motion to move up and down. This motion of the needle in repeated fashion helps it pierce through the pieces of fabrics with ease. Hence, reciprocating motion plays a major role in stitching clothes.
2. Reciprocating Pumps
A reciprocating pump is used to convert mechanical energy into hydraulic energy. These types of pumps are used to transport water or fluid from lower pressure regions to higher pressure regions. When the power source is turned on, the crankshaft begins to rotate. The movement of the crankshaft is further responsible for the reciprocating motion of the piston inside the cylinder. The repeated back and forth motion of the piston leads to the formation of a partial vacuum in the cylinder, which helps the liquid enter into the suction pipe, thereby allowing the water to be extracted easily.
3. Door Bell Ringer
An electric doorbell is one of the prominent examples of reciprocating motion. When the doorbell switch is pressed, the internal circuitry of the bell gets completed. This enables the hammer to strike the gong repeatedly. This repeated back and forth movement of the striker represents the reciprocating motion.
4. Reciprocating Engines
A reciprocating engine makes use of the reciprocating motion exhibited by one or more pistons to convert pressure into rotational motion. Some of the types of reciprocating engines include the internal combustion engine, i.e., the engine used in motor vehicles, the external combustion engine, i.e., the steam engine, the Stirling engine, etc. The limitation of using reciprocating engines is that the cooling mechanism of such engines produces low-grade heat.
5. Movement in Loudspeaker Coil
A loudspeaker is used to convert the electrical signal into an acoustic signal. This is done with the help of the reciprocating motion of the loudspeaker cone. The loudspeaker cone is attached to a conducting coil, which is further connected to a magnet. When the circuit is supplied with electric current, the Lorentz force gets developed that causes the coil to accelerate on its own axis, thereby causing the coil to move up and down and exhibit reciprocating motion. This reciprocating motion of the coil is transferred to the cone, which is then utilized to produce a higher amplitude sound wave.
6. Shaper Machine
A shaper machine is a machine commonly used in production industries. It consists of a fixed bench vice that is used to hold the workpiece in position and a movable cutting tool that is held by a Ram. When the machine is supplied with electrical power, the ram reciprocates with respect to the table. This further causes the cutting tool to exhibit the reciprocating motion and shape the workpiece. A shaper machine is most commonly used to make gear teeth and internal splines.
7. Power Hacksaw Machine
A power hacksaw machine makes use of an electrically powered saw blade to cut the large sections of metals. It consists of electric motors that power the blade via a pulley system. The rotary motion of the motor gets translated into reciprocating motion. Hence, the arm of the power hacksaw repeatedly moves back and forth. These continuous strokes make the cutting easy and precise.