The Science Behind Rotary Screw Air Ends: Explained
Discover the science behind rotary screw air ends and how they work in this informative guide. Get a better understanding of this essential component of air compressors.
What is a rotary screw air end?
The rotary screw air end is the essential component of a screw-type air compressor, acting as the heart of the compressor. Its performance and condition directly affect the overall performance level of the machine and the operational status of the equipment. If the design of the air end is not reasonable, the processing is not up to standard, maintenance is not timely, or operation is not standardized, it may cause air end failure, and in severe cases, even lead to equipment scrapping.
Common faults of Rotary Screw Air End
The most common issues with rotary screw air ends include excessive noise and vibration, high temperatures, seizing or locking up of the main unit, leaks, failure to start, and poor performance that cannot meet the demands of the end-use application. Excessive noise and vibration can be identified by a high-pitched screeching sound and noticeable shaking during start-up. High temperatures can trigger the high-temperature protection system, causing the main unit to shut down. Seizing or locking up of the main unit can occur suddenly during operation. Leaks can manifest as oil or air escaping from the unit. Failure to start can be caused by a variety of factors. Poor performance can be identified by low air flow and high power consumption.
How to troubleshoot a rotary screw air end?
- The rotary screw air end can sometimes produce excessive noise and vibration, which can be caused by mechanical collisions, improper machining of bearings and gears, and other factors. To address this issue, relevant equipment can be used to analyze the sources of vibration and noise, such as through frequency analysis, FFT analysis, and time-domain analysis. Once the problem is identified, appropriate measures can be taken to resolve it.
- If the air end is running at a high temperature, it could be due to insufficient oil supply or a problem with the cooling system, such as blockage in the oil passages. To diagnose the issue, a flow meter can be used to check if the oil supply is sufficient and the temperature of the oil intake is not significantly higher than the ambient temperature, ensuring that the cooling system is functioning properly.
- Air end failure can occur for a number of reasons, including design or manufacturing defects that cause the host to seize up. Foreign objects, such as debris from mechanical wear or unfiltered particles in the air, can also enter the host and cause it to malfunction. Additionally, a clogged oil filter can lead to poor lubrication and high temperatures. To address this issue, it is important to check the design data and part precision, which can be done through three-coordinate testing. It is also crucial to manually inspect the host for foreign objects before starting it up, by performing a “hand-cranking” check to ensure that no debris has entered the chamber through the air intake.
- The air end can experience leaks due to design factors such as improper bolt spacing. If the spacing is too small, the shell may deform due to positional tolerances, while too much spacing can result in insufficient bolt tightening and subsequent leaks. The selection of O-rings must also be appropriate for different working conditions and materials. Additionally, damage to the shaft seal or sand holes in the shell can also cause leaks. Before testing, the air end must undergo an airtight seal test, and any casting defects such as sand holes must be replaced.
- The air end of rotary screw air compressor can be affected by poor performance and insufficient air flow, which can be caused by inadequate intake or gas leakage. It is important to check the design and assembly parameters to ensure they are consistent, as well as inspecting the intake and leakage points of the machine. If the machine is consuming too much power, it may be due to excessive fuel injection, which is often a design issue. During operation, the machine is cooled by fuel injection, but if too much fuel is injected, it can lead to increased power consumption. To address this issue, the fuel injection rate should be adjusted and the precision of the machine’s components should be checked.
How to maintain a rotary screw air end?
The air end of a compressor requires specific tools and equipment for disassembly, repair, and reassembly. Common wrenches can be used to remove the main screws, while hydraulic pullers are needed for bearing removal and customized tools are required for shaft seal removal depending on the specific machine model. Repairing the air end involves using grinding, cleaning, measuring, and machining tools and equipment. Assembling the air end requires a rotating table, torque wrenches, bearing heating equipment, and installation tools. After assembly, it is essential to conduct air tightness and performance testing using specialized testing equipment.
