From industrial machines to the vehicle engine, piston uses are many and varied. Pistons also come in different sizes and designs.
To cater to the many applications, piston manufacturers use a wide range of materials to make these parts.
Here, we bring you the use of pistons in different sectors; automotive, industrial, and medical.
Automotive Piston Applications
The most widespread use of pistons (and perhaps the most useful) is in the engines of motor vehicles. Ask any car expert or mechanic, and they will tell you how the piston is one of the most important parts of a vehicle.
The reason? Every automobile that uses a reciprocating engine relies on pistons to move. These engines are also called, as you can guess, piston engines.
What is a Piston Engine?
A piston engine, as the name implies, uses a piston or pistons to produce rotation. The piston moves in a lubricated cylinder. Its movement works the crankshaft, which is also one of the essential piston engine parts. The crankshaft, in turn, connects to other components to move the vehicle.
To make the piston cylinder almost airtight, manufacturers recommend specific values for the gap between the piston and cylinder walls. This is commonly called piston clearance. There is also the recommended space at the bottom known as piston deck clearance. Again, this gap should be maintained at all times for the proper operation of this important component.
The main piston function in an engine is to transform the pressure of hot gases into rotational energy. Because the piston in engine cylinders operates in a high-temperature environment, the material used to make it should not melt easily. Automotive piston manufacturers often use aluminum to make these parts. Iron is also used. However, it is not a popular piston material.
Piston Engine Configurations
Piston engines are often named according to the number of cylinders it uses. Because most engines use one piston in every cylinder, it turns out that engine name denotes the number of pistons. A 4 cylinder engine, for example, means the engine contains four cylinders and, therefore, four pistons.
A piston in cylinder bore moves rhythmically to these stages: fuel/air mixture intake, combustion, and expulsion of exhaust gases. Each of these phases represents what is known as a piston stroke. For proper piston engine operation, all these strokes must happen at the right time and correctly. That usually depends on the piston position, the condition of its head, and other situations not related to the piston.
Unless an engine uses a single cylinder, it will have a piston set that consists of two or more of these parts. Smaller engines use one piston or two. These include most piston motorcycle engines, those used in lawnmowers, and others. Bigger ones, such as the piston engine of aircraft, will have many pistons and produce an incredible amount of power.
Automotive piston design varies slightly across different pistons. Sizes, too. Overall, these engine parts look almost similar and operate the same way. The piston of diesel engine resembles the piston of engine that uses gasoline. Usually, the vehicle owner preferences dictate the type piston type to use.
The piston fuel engine system depends on the type of fuel the engine is meant to use, and rarely the type of piston. It does not even matter the piston cylinder assembly, which remains the same for both diesel and petrol engines.
Automotive Piston Parts
Engine pistons are made up of several parts:
Crown or head, skirt, rings and ring grooves, wrist pin and its bearings and fasteners, connecting rod and its bearings and bolts. Among these piston parts, the rings wear out the fastest. The good thing is that you can replace them individually.
Sometimes, the piston assembly contains several parts that need changing. A piston kit is then required. It contains several components. Piston price and piston kit price varies across retailers. Automotive piston suppliers or retailers will have different rates for the part. It depends on the model, material, and other factors. The amount may be as low as $200 to as high as $500 or more.
Other piston Uses in a Vehicle
so far, we have looked at the uses of pistons in the engine of motor vehicles. But that is not the only place where pistons are needed. The brake system also relies on pistons to work. Although the pistons used here are smaller and less sturdy, they serve an important role in the running of a vehicle. Piston uses in the in brakes include:
Disc Brakes- disc brakes use calipers to hold the mechanism that pushes brake pads onto the brake discs. Inside the calipers are pistons. A floating piston caliper contains one piston, while a fixed caliper uses 2 or more. A 1 piston caliper brake is mostly found in small cars where a large stopping force is not necessary. A 2 piston brake caliper too.
In a 2 piston caliper system, there is one piston on either side of the brake disc. A 4 piston brake calipers means two pistons on every side. Because the number of pistons on either side must equal, other types of fixed calipers include the 6 piston caliper and the 8 piston caliper.
Piston brakes with a lot of braking power usually use a 4 piston caliper and are called 4 piston brakes. A 6 piston brake and 8 piston brake arrangements are usually used in the heavy-duty braking systems of big vehicles. These produce a higher stoppage power since they clamp the brake rotor with more force.
Drum Brakes- drum brakes use pistons to produce braking force. Unlike in the disc brakes, the pistons here move brake shoes to make contact with the drum. Return springs pull the shoes back when you release the brake pedal.
Master Cylinder- the master cylinder contains hydraulic fluid. The fluid moves from a reservoir into the brake lines, hoses, and the cylinder at the wheels. Here is where brake pads or shoes are located. The fluid must be pushed, and pistons in the master cylinder serve that purpose. A typical master cylinder contains two pistons working together to respond to the pressure applied on the brake pedal.
Industrial Piston Applications
Industrial piston uses vary greatly. You will find these devices in automation systems, machines that exert pressure on fluids, and more.
One of the major piston uses in this sector is in the air compressor. Air compressors take in air, compress, and expel it at high pressure. The machines valves to operate at the required pressure levels. A piston valve, just like any other type of valve, opens to allow air to pass through. The machine can be a 1 or 2 piston air compressor. It depends on the required performance.
A piston type pump uses reciprocating pistons to displace fluids. They are found in a wide range of applications, an example being the piston water pump. These types of pumps differ in the number of pistons. It can be a 1,2 or 3 piston water pump. The more the pistons, the higher the force.
Piston pump parts also vary. The design, too. In a nutshell, there are piston hydraulic pump types. Other common piston uses in industries include the piston motor and the piston elevator. A piston pump exerts pressure on a fluid to provide higher forces. These pumps can be found in construction equipment. A piston elevator, as the name suggests, is an elevator that is operated by a piston moving inside a cylinder.
Medical Piston Application
In the medical industry, one of the piston uses that should come to mind is the syringe. A piston syringe comprises a cylinder, piston, and pushrod. Apart from the syringe, there are other medical tools and equipment that use pistons. These include metering equipment that supply specific quantities of a fluid, among other uses. You will also find an occasional piston pump and piston hydraulic systems in hospitals medical research facilities.
Piston uses cover many sectors and applications. The automotive industry is one of the sectors where pistons are used the most. It is no wonder then, that the automotive piston market is experiencing growth. Having looked at the uses of pistons, it you may want to know about the part that make these devices. Check out our piston engine parts and functions article.