15+ Reciprocating Motion Examples: Detailed Explanations

Detailed explanations on several reciprocating motion examples that we come across in our daily life will be covered in this article.

Reciprocating motion is somewhat similar to vibratory motion since the motion repeats but the former mostly includes back-and-forth or up-and-down linear motions. Some of the examples are:

• Movement of a needle in a sewing machine
• Door bell ringer
• Reciprocating Pumps
• Reciprocating Engines
• Power hacksaw machine
• Shaper machine
• Movement in loudspeaker coil
• Expansion of the burning fuel in cylinders
• Hand operated well pump
• Electrically driven oil well pumps
• Diaphragm pumps
• Steam engines
• Impact hammers
• Pile drivers
• Reciprocating compressors

A detailed explanation for the above examples will be discussed further.

Reciprocating Motion Examples

Motion of a needle in a sewing machine

The up and down motion of a needle in a sewing machine is one of the best examples demonstrating the reciprocating motion. The needle constantly moves up and down when the machine is working. This repeated motion helps the needle to pierce the fabric easily and desired stitching can be obtained. Thus stitching clothes deploys reciprocating motion of the needles.

Door bell ringer

Another instance of reciprocating motion can be observed in an electric doorbell ringer. The mechanism behind its working is very simple. When the switch is pressed, the electric circuit inside the ringer gets completed and now, the hammer strikes the gong repeatedly. This motion represents a reciprocating motion.

Reciprocating Pumps

Reciprocating pumps are mostly used to transport fluids (commonly water) from lower pressure region to a region of high pressure. The energy conversion behind the working of such pumps is mechanical to hydraulic energy.

Crankshaft is an essential part of pumps. When power supply is given to the pump, this crankshaft rotates and this motion is responsible for the motion of piston. The piston moves back and forth repeatedly and such movement is reciprocating motion. The consequence of this motion is that it creates a partial vacuum in the cylinder that aids the entry of fluid into the suction pipe allowing the fluid extraction easily.

Reciprocating Engines

Reciprocating engines mainly deploy pistons and converts pressure to rotational motion. The movement of the piston displays reciprocating motion. Internal combustion engines and external combustion engines, both are examples of reciprocating engines.

Power hacksaw machine

Power hacksaw machine is equipment mainly used to cut large sections of metals and for this, it deploys an electrically powered saw blade. There is an electric motor as well as a pulley system within the machine and the blade receives power from electric motor through the pulley system. The rotary motion of the electric motor gets converted to the reciprocating motion in this device. The power hacksaw exhibits a back and forth motion and this is known as reciprocating motion. This movement aids in cutting materials quickly and easily.

Shaper machine

Production industries use shaper machines commonly to make gear teeth and internal spines. The machine consists of a movable cutting tool held by a ram, and a bench vice. When electrical power is supplied, ram rotates with respect to the table causing the cutting tool to move in a reciprocating fashion. This motion helps the cutting tool to shape the workpiece.

Movement in loudspeaker coil

The loudspeaker converts electrical signal to acoustic signal. Loudspeaker cone attached to a coil, further attached to a magnet is what exhibits reciprocating motion. This motion is initially produced by the coil as a result of the Lorentz force which is developed when electric energy is supplied. The reciprocating motion of the cone is then used to produce an acoustic wave with higher amplitude.

Expansion of the burning fuel in cylinders

The reciprocating motion due to the expansion of the fuel that is burning in cylinders takes place in engines. This expansion is what moves the piston periodically and thereby turning the crankshaft of engine.

Hand operated well pump

Manually operated hand pumps contains pistons that exhibit reciprocating motion. The pump is operated manually to transport fluids. When someone pulls the handle of the pump upwards, it makes the piston to go down. This develops a suction which aids in drawing water from the well. The piston movement is the reciprocating motion in this context.

Electrically driven oil well pumps

Electrically driven oil well pumps also works based on the same mechanism as a hand driven pump. The only major difference lies in the fact that there is a rotary electric motor that drives an oscillating arm. This as a whole makes the pump to function. The reciprocating motion is observed in the oscillating arm.

Diaphragm pumps

Diaphragm pumps can also be considered a reciprocating machine which is mainly used for fluids that contains solids, like mud or chemicals. There is a connecting rod that pushes the diaphragm back and forth, and due to this reciprocating motion, fluid is drawn in and discharged.

Steam engines

In a steam engine too, a piston is pushed back and forth or up and down in response to the position of the cylinder. If steam gets admitted to the cylinder’s top, it expands and as a result, pushes the piston to the bottom. Similarly, if steam gets admitted to the cylinder’s bottom, piston is pushed up. This back and forth motion or reciprocating motion is the main principle of operation in steam engines.

Impact hammers

The impact hammers function similar to the drills. Reciprocating motion forms a major part in its functioning.

Pile drivers

Pile driver is a heavy tool that is used to drive piles into the ground for the purpose of building bridges, poles or other structures which are supported. The pilings required for the purpose may be a material made of wood or steel depending on the need. Recent pile driving equipments use diesel, steam or electric power. In the case of diesel hammer, a piston-cylinder system is where reciprocating action takes place.

Reciprocating compressors

Refrigeration and air conditioning systems deploy reciprocating compressors. They function on the same arrangement as that of an automotive engine comprising pistons and cylinders. When combustion of fuel takes place, power is generated in the engine which is used by the compressor to compress the refrigerant. The piston does a reciprocating motion inside the cylinder.