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Rotary Air Compressor Parts and How They Work

There are different types of air compressors out there, though the most common being the rotary air compressors. In order for this rotary-type positive-displacement mechanism to work, it requires quality air compressor parts and constant maintenance.


One of the most common reasons why compressors fail is due to parts of your compressor wearing out. On the chance that this occurs, you would have to replace these parts rather than getting rid of your air compressor altogether.  But in order to do so, you would primarily need to know what those air compressor parts are and what they do.


The following infographic enumerates the different components of an air compressor and explains how these parts come together to make it work.


Anatomy of an Air Compressor: Parts and Their Functions

Rotary air compressors are just like the human body: they have several systems working together in order for it to work. Here are the ins and outs of an air compressor and its functions.


Air Compressor Components


Air Ends: The Heart of the Air Compressor

This air compressor part is the most important component of the system that performs the air compressor’s main function. Here are the different parts of the air ends.

     • Inlet Valves 

Air enters through the inlet or suction valves where it will be mixed with oil to get compressed. 

     • Rotors

These two screw-like components are connected to the motor, constantly “rolling” or rotate in order to generate power in the air compressor. Air gets sucked in, gets compressed by the spinning, and circulates further down the line.

Fact: The bigger roller is called the male rotor and the other is the female rotor. This design was done to make rotations faster.  

     • Bearings

Bearings secure the rotors tight and in place, making sure they stay rotate evenly and can function to their full capacity. They are usually made to be anti-friction and anti-corrosion in order to serve this function.

     • Discharge Valves

Opposite to inlet valves, these air compressor parts are at the opposite end. Once the compression process is completed, the discharge valves allow the air to flow out into the storage tank or the discharge pipe for immediate application.

     • Compression Cylinder

This is the frame of the air end system that holds together the rollers and the rest of the components. 



The motor gives power to the rotors while, in turn, the rotors run the main function of the compressor. They are usually designed to harness enough power for around-the-clock function.

Fact: Most motors are electrically powered, though there are some gas-fueled motors under development.   

Storage Tanks

The air that is discharged often goes to the storage tanks, which keeps the unused air until needed.


Often found in oil-inject compressors, these serve as another line of defense against oil and other impurities from the final gas system needed by the machine.

Gaskets & Seals

These air compressor parts make sure that your system stays air-tight and free from damage and leakage. They make sure everything stays in place and compressions systems function efficiently and effectively. 

Air Filters   

Air filters or air cleaners are the regulatory maintenance team of their air compressors. They take care of the air impurities such as moisture and debris. These are usually attached to air compressors and are always recommendable to have. 

Oil Filters

Like air filters, oil filters clean and maintain the gas purity of compressed air. It takes out the impurities from oil that shouldn’t re-enter the air compression system. This filter can be found on the compressor, the separator tank, or mounted on a filter manifold.


How Rotary Air Compressors Work

  • Air Enters through the Inlet valve, which is then sucked into the rotors for compression. 
  • The air is trapped between the female and male rotors and is released through the discharge valve.
  • Fluid is injected for the air to be cooled, which is later separated. The compressed air goes through filters in order to be suitable for the application.
  • The cooled and compressed air goes to the storage tank, ready for use.

All the parts of a rotary air compressor, no matter how small or big, have their own specially designed function that serves a purpose to the process. Knowing what these basic components will not only help you troubleshoot problems but will also give you a sense of appreciation of this fine piece of machinery and the applications that it is capable of.


Also Read: Buying Guide: Finding the Perfect Air Compressor for Your Business


On the lookout for quality rotary air compressors or in need of spare parts for your own?  Compresstech Resources Inc. is a trusted supplier of high-quality compressors and spare parts from renowned manufacturers across the globe. Contact us now for further inquiries!