1. Gear drive and belt drive
In the drive system of air compressor, it can be divided into direct drive and belt drive.Direct transmission of screw air compressor refers to the motor spindle through the coupling and gearbox speed to drive the rotor, which is not really a direct transmission.True direct drive means that the motor is directly connected to the rotor (coaxial) and the speed is the same.This is obviously rare.
Another type of transmission is belt drive, which allows the speed of the rotor to be changed by pulley with different diameters.
It is worth mentioning that the manufacturers who advocate direct gear drive also use belt drive for some of their products.
Comparison of gear drive and belt drive:
Efficiency of 1.
Excellent gear transmission efficiency can reach up to 98-99%, excellent belt transmission design can achieve 99% efficiency under normal working conditions.The difference between the two does not depend on the choice of transmission mode, but on the manufacturer's design and manufacturing level.
2. No load energy consumption
For gear direct transmission, the no-load pressure is generally maintained at more than 2.5bar, some even up to 4bar, to ensure the lubrication of the gear box.
In the case of a belt drive, the no-load pressure can theoretically be zero because the oil drawn into the rotor is sufficient to lubricate the rotor and bearing.
Take a 160kw gear driven air compressor as an example, the annual work of 8000 hours, of which 15% (namely 1200 hours) of the time for no load, this machine every year than the belt drive with the power of the air compressor will consume 28800kwh of electricity, in the long run, this will be a big cost.
3. The loss of oil
Experienced practical users know that the gearbox will be the first to suffer in the event of an oil loss.There is no such safety issue with the belt drive system.
4. Design work pressure according to user requirements
Generally, the working pressure required by the user is not completely consistent with that of the manufacturer's standard models.For example, the pressure required by the user is 10bar. Depending on the condition of post-processing equipment, pipe length and sealing degree, the working pressure of the air compressor may be 11 or 11.5bar.In this case, an air compressor rated at 13bar is usually installed and the outlet pressure is set to the required working pressure on site.At this time, the exhaust volume will remain basically unchanged, because although the final working pressure is reduced, the rotor speed does not increase.
On behalf of modern technology belt drive design manufacturers simply change the diameter of the pulley and the working pressure can be designed to meet the requirements of users, so that users with the same power of the motor can get more air.For gears, it is not so convenient.
5. Pressure change of air compressor installed
Sometimes due to changes in customer production process conditions, the original purchase of the design of air compressor pressure may be too high or too low, hope to be able to change, but for gear transmission of air compressor, this work is very difficult and expensive, and for belt transmission type air compressor is easy, simply replace the pulley.
6. Install new bearings
When the rotor bearing needs to be replaced, for the air compressor with gear transmission, the gear box and the main shaft bearing of the gear box need to be overhauled at the same time, and the cost is difficult for users to accept.For the belt drive air compressor, there is no such problem.
7. Replace the shaft seal
Any screw air compressor USES a ring shaft seal, to a certain life need to be replaced.For the geared air compressor, the motor must be separated from the shaft coupling before it can be close to the shaft seal, which makes the work time-consuming and laborious, thus increasing the maintenance cost.For belt-driven air compressor, it is much easier to remove the pulley first.
8.Motor or rotor bearing damaged
For gear driven air compressor, when the motor or rotor bearing is damaged, it will damage the important parts directly and indirectly.For the belt drive air compressor does not exist in this situation.
9. Structural noise
For the geared air compressor, due to the rigid connection between the motor and the rotor, the vibration of the rotor in the compression chamber will be transferred to the gear box and the motor bearing, which not only increases the wear of the motor bearing, but also increases the noise of the machine.