A reciprocating piston compressor is a tool used by part manufacturing shops to power pneumatic machines, among other uses. It is popular in part manufacturing and other industries due to its versatility, cheapness, and eco-friendliness.
You must understand its working principle and basic structure to harness the machine’s full potential as a metal manufacturer. Hence, this article will introduce reciprocating piston compressors so you can decide whether to incorporate them in your workshop.
What is a Reciprocating Piston Compressor?
A reciprocating piston compressor is a gas compressing machine used to increase the pressure of a gas. It sometimes stores the compressed gas or delivers it immediately to a working industrial system.
At every cycle, the amount of air sucked in and compressed is constant. Hence, reciprocating air compressors provide a steady source of compressed air.
Structure of a Reciprocating Piston Compressor
As a CNC machine shop looking to use a reciprocating piston compressor, you must know that pistons come in different sizes and configurations. However, every compressor has at least a cylinder, piston, crankshaft, intake valve, outlet valve, cooling system, and lubrication system.
- Cylinder
The cylinder houses other machine components and experiences compression. It is made from durable materials like cast iron, aluminum, and steel. Plastics like polytetrafluoroethylene (PTFE) and fiberglass-reinforced plastic can also be used.
- Piston
The piston compresses the gas/air by moving back and forth in the cylinder. It is made with a material that can handle the rigorous compression cycle. The cylindrical piston has two regions: the skirt and the head. The skirt guides the piston movement while the domed or flattened head seals the combustion chamber.
- Intake Valve
The intake valve is like a poppet valve, controlling airflow into the cylinder. It has four subcomponents: head, stem, seat, and spring. They all allow gas inlet and prevent gas escape.
- Outlet Valve
Outlet valves are similar to the intake valves but have opposite functions. They control the flow of compressed air from the cylinder for different applications.
- Crankshaft
The crankshaft converts motor motion to piston motion. It is made of a material that can handle the fatigue associated with energy conversion and connects to the piston via a wrist or piston pin.
- Cooling and Lubricating System
Reciprocating piston compressors also have cooling and lubricating systems that dissipate heat generated during compression and reduce wear and tear.
Types of Reciprocating Piston Compressor
Before you incorporate a reciprocating piston compressor in the standard operating procedure of your CNC machine shop, you need to know the different types. You can classify the compressors based on the number of stages or the compression cycles. Here is an explanation of each type.
Classification based on the number of stages
There are three types of compressors based on the number of stages, there are three types: single-stage, two-stage, and multi-stage compressors.
- Single Stage Compressors
Single-stage compressors have a simple design that comprises a single cylinder, motor, and piston. Here, gas compression to the required pressure occurs in a single step. As a result, they are suitable for producing moderate pressure ratios.
- Two-Stage Compressors
These compressors have a more complex design compared to single-stage compressors. They have two cylinders, each at a different pressure and with the other necessary components. Compression occurs in two stages.
In the first stage, the air is partially compressed before being transferred to the second cylinder, where final compression occurs. These compressors generate a larger pressure differential than single-stage piston compressors and are used in small and medium-scale CNC machining services.
- Multi-Stage Compressors
These types of compressors have several cylinders, each at a different but progressively higher pressure. They follow the system explained in two-stage compressors but deliver a higher pressure, hence their application in petrochemical plants and power generation. Furthermore, they are efficient and reliable, although more complex and require more resources. Multi-stage compressors are used in CNC machining to deal with high-volume production.
Classification based on compression cycles
There are two types of reciprocating piston compressors based on the number of compression cycles. They are:
- Single Acting Compressors
In a single-acting compressor, gas suction and compression occur simultaneously. They generate moderate pressure. Hence, they are suitable for small workshops where they are used to power small pneumatic tools.
- Double Acting Compressors
A double-acting compressor has two inlet valves and two outlet valves per cylinder. As a result, it makes it possible to compress the gas during suction and compression strokes.
How Does a Reciprocating Piston Compressor Work
Whether the compressor is classified based on the number of cycles or stages, they have a general mechanism.
The crankshaft facilitates the piston’s back-and-forth movement. When the piston moves downward or backward, air enters via the intake valve. When it moves forward or upward, the intake valve closes, and compression occurs, increasing pressure.
Finally, the outlet valve opens, discharging the compressed gas to its point of application, for example, in machining shops where it is used to power pneumatic tools.
The Function of Reciprocating Piston Compressors
Due to its functions, the compressor is versatile and indispensable in several industries—generally, it functions in gas compression and storage of compressed gas before being released.
The compressed gas is then used in the following ways:
- Powering air-powered pneumatic tools such as drills and wrenches in part manufacturing, especially by CNC machining services.
- Powering of robotic arms
- Construction for powering conveyor systems
Advantages of Reciprocating Piston Compressors
Advantages of using the machines include:
- They are cheap
The piston compressor is cheaper to buy than other types, which is why it is popular in small workshops.
- Easier Maintenance
Due to their simple design, they are compact and portable. Hence, they are easier to transport and maintain. Furthermore, the machine’s spare parts are cheap.
- There are different options.
Depending on the application, you can choose a compressor powered by an electric motor or internal combustion engine. The former is suitable for small workshops, while the latter is suitable for larger fieldwork.
- They are versatile
Their different designs mean they can handle different air volume and pressure requirements. This increases their diverse applications in different industries, whether powering pneumatic tools, construction tasks, or supporting automotive operations.
- They are efficient
These compressors consume less energy to deliver optimal compression ratios. Their structure and material makeup allows them to meet the rigorous demands of their operation environment. Hence, they can adapt seamlessly to diverse industrial settings.
Conclusion
A reciprocating piston compressor is a machine that uses the gas/air compression mechanism. Understanding its working principle and basic structure is the key to harnessing its full potential. We hope this article introduces the machine so you can incorporate it into your workshop.
