What Is an Oil-Free Compressor?

Oil-free compressors refer to compressors that do not use lubricant in the compressor cylinder. The crankcase of the oil-free compressor has a dry structure, and its connecting rods have large and small holes, and the front and rear main bearings of the crankshaft generally use double-port sealed grease-containing ball bearings. During operation, there is no lubricating oil in contact with the compressed air source, so the exhaust gas is free of oil and gas, so it is welcomed by users. However, the grease sealed in the bearing will evaporate and oxidize and decompose the grease due to temperature rise during long-term operation, and the thickener in the grease will also deteriorate and lose the thickening effect. Due to the change in grease properties, the use effect has dropped sharply. If new oil is not added in a timely manner, it will directly damage the bearings and even the machine.

A compressor that does not use lubricant in the compressor cylinder. With the rapid development of the national economy, the market demand for clean and oil-free compressed gas sources has also increased dramatically. In the demand of low pressure and small flow, the miniature all oil-free lubrication compressor plays a very important role. After a short period of more than ten years, China has had certain design, development and processing capabilities. To meet the needs of the market, some companies have made important contributions and achieved impressive results. But the traditional structure has always been unsatisfactory, hindering the development of the machine and further expanding the user base ^[1]

The crankcase of the oil-free compressor has a dry structure, and its connecting rods have large and small holes, and the front and rear main bearings of the crankshaft generally use double-port sealed grease-containing ball bearings. During operation, there is no lubricating oil in contact with the compressed air source, so the exhaust gas is free of oil and gas, so it is welcomed by users. However, the grease sealed in the bearing will evaporate and oxidize and decompose the grease due to temperature rise during long-term operation, and the thickener in the grease will also deteriorate and lose the thickening effect. Due to the change in grease properties, the use effect has dropped sharply. If new oil is not added in a timely manner, it will directly damage the bearings and even the machine. In addition, grease also has a certain working period, coupled with poor operating conditions, this will affect the service life of the grease. Therefore, after using the machine for a period of time, you should consider adding new grease to the bearing.

Due to the particularity of the structure of all oil-free lubrication compressors, after a period of use, it is very difficult for users to add new grease according to the requirements of use. For structural reasons, many parts of the machine must be removed, and some should have special tools. If the user has not learned or has certain professional knowledge, this fat work is difficult.

Up to 220bar, high pressure can provide 1, 2, 3 compression;

Flow reaches 14m ³ / min (special requirements can be customized);

Compressible gases: nitrogen, argon, helium, natural gas, carbon dioxide, LPG, sulfur hexafluoride, refrigeration gas, methane and other various compressible gases ^[2]

1. Modular design is to obtain different performance requirements by replacing standard bores of different sizes at a small cost.

2. The compressor seal design absolutely prevents harmful gas from leaking.

3. Six types of piston ring and stuffing box materials are available to suit different specific gas applications.

4. Can provide air cooling and water cooling.

5. Pressure lubricated bearings extend bearing life and increase bearing size.

6. Isolate the cylinder section to prevent oil vapor from entering the cylinder, no need to install a post-filter device

7. The vertical crosshead structure ensures oil-free compression, avoids the piston ring from being affected by lateral forces, and improves the life of the crosshead.

8. In the multi-stage compression, the enlarged intercooler ensures the cooling of the secondary and tertiary components.

9. The thick cast iron cylinder and cylinder head reduce the warpage of the machine and reduce the vibration of the machine.

10.Large size, low lift stainless steel valve has longer life and more efficient. The valve can be replaced without removing the cylinder head.

11. Gas-sealed floating design provides longer life and better sealing.

12. Thickened piston ring design, using engineering polymer material.

13. The equipment should be tested at least 4 hours before leaving the factory, especially for the customer's specific conditions.

14. Industrial heavy-duty design to ensure continuous operation.

In 1969, Mr. B.zimmern of France invented the first high-sealing and high-efficiency

When designing an oil-free compressor, the cylinder volume should be selected to meet the flow requirements. An electric motor is used to drive the compressor. The minimum service life of the piston ring and piston skirt should be 10,000 hours. The service life of connecting rod ball bearings and piston pin needle bearings should be at least 20,000 hours ^[3] .