When purchasing a screw air compressor, users are often faced with the choice between belt drive and direct drive as the two main transmission methods.To determine which transmission method is more suitable for them, there are a number of factors to consider.
High-quality direct drive systems can achieve efficiency levels of 98% to 99%, and well-designed belt drive systems can also attain an efficiency of 99% under normal working conditions. Therefore, the choice of transmission method is not the key factor; the crucial aspect is the manufacturer’s design and manufacturing quality.
No-load Energy Consumption
1. For the direct drive transmission method, the no-load pressure is typically maintained at 2.5 bar or higher, and in some cases, it can even go as high as 4 bar, to ensure lubrication of the variable speed gearbox.
2. In the case of belt drive transmission, theoretically, the no-load pressure can be zero, as the oil drawn in by the rotor is sufficient to lubricate the rotor and bearings. Generally, for safety reasons, the pressure is maintained at around 0.5 bar.
3. Installing new bearings. When the rotor bearings need replacement, for direct drive air compressors, both the gearbox and the gearbox’s main shaft bearings need a major overhaul, which can be costly. This issue does not exist for belt drive air compressors.
4. The pressure of the installed air compressor has changed. Sometimes, due to changes in the user’s production process conditions, the design pressure of the originally purchased compressor may be too high or too low, and there is a desire to make changes. However, for gear-driven compressors, this task can be very difficult and expensive. In contrast, for belt-driven compressors, it is a straightforward task and can be accomplished by simply replacing the pulleys.
5. Damage to the electric motor or rotor bearings. In the case of direct drive air compressors, when the electric motor or rotor bearings are damaged, it often leads to both direct and indirect double damage to connected important spare parts. This situation doesn’t apply to belt driven air compressor.
6. Equipment maintenance. All screw-type air compressors use a type of circular shaft seal that needs replacement after a certain service life. For direct-drive air compressors, the motor and coupling must be separated before approaching the shaft seal, making this work time-consuming and laborious, thus increasing maintenance costs. In the case of belt-driven air compressors, the process is much easier since only the pulley needs to be removed. However, belt-driven air compressors are prone to belt wear during operation, necessitating periodic belt replacements and increasing the workload for maintenance and repairs.
7. For the direct drive transmission method, the first victim in the event of oil loss will be the transmission gearbox. There is no such safety issue with the belt drive system.
8. Structural noise. In the case of direct drive air compressors, because the electric motor is rigidly connected to the rotor, the vibration of the compressor rotor is transmitted to the gearbox and motor bearings, which not only increases the wear of the motor bearings, but also increases the noise of the machine.
Elang provides two different transmission methods for air compressors.
Elang Belt Driven Screw Air Compressor
Belt driven, which allows the speed of the rotor to be changed by different diameter pulleys.
1. The belt tension for each operating condition is optimized
2. By avoiding excessive start-up tension, greatly extending the belt working life
3. Always ensure the correct pulley connection
4. Replace the belt is very easy and fast, and do not need to adjust the original settings
5. The whole belt driven system safe and trouble-free operation.
Elang Direct Driven Screw Air Compressor
1. Large displacement: Displacement 10% higher than ordinary piston compressor.
2. Energy-saving: Compared with piston air compressor, this series of models for the new national standard two energy efficiency products, excellent energy saving.
3. Easy to operate: 24 hours unattended all day work, free load automatically start, full load automatically shut down.
4. Strong stability: Under long time working, displacement and pressure stable, no crash phenomenon, low failure rate.
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