How to solve the problem of screw compressor rotor failure? This is a problem that troubles many beginners. Now let me help you solve it.
1, Rotor components
The rotor component consists of active rotor (male rotor), driven rotor (female rotor), main bearing, thrust bearing, bearing cover, balance piston, and balance piston sleeve.
2, General fault phenomena of yin and yang rotors
1. Normal mechanical wear and aging
Wear on the outer diameter of the rotor's internal and external teeth;
Normal wear and tear of the rotor cylinder;
2. Artificial mechanical damage
Scratches on the outer diameter of the Yin Yang rotor teeth path;
Scratches on the rotor cylinder;
Scratches on the side of the rotor intake and exhaust end cover;
Wear of the intake and exhaust end bearings and wear of the inner circle of the bearing end cover;
Wear of rotor bearing position and shaft diameter;
The shaft end of the rotor is deformed.
3. General parts that are scratched or stuck
Scratches and jamming (bite) between the Yin and Yang rotors;
Between the outer diameter of the rotor and the inner wall of the machine body;
Between the exhaust end face of the rotor and the exhaust bearing seat;
Between the shaft neck of the rotor suction end and the shaft hole of the body;
Between the shaft neck of the rotor exhaust end and the shaft hole of the exhaust bearing seat.
3, Cause of malfunction
1. The air filter element was not replaced in a timely manner, resulting in poor intake quality and severe rotor wear; The arbitrary use of lubricants with different brands can often lead to cross-linking and rotor wear;
2. The use of compressor oil with an unqualified model or failure to replace it in a timely manner according to regulations, resulting in excessive impurities in the oil and causing scratches on the rotor and cylinder barrel;
3. The exhaust temperature during operation is too low, resulting in excessive moisture in the oil and gas. Prolonged operation can cause oil emulsification, resulting in ineffective lubrication of the inlet and exhaust end bearings during high-speed and heavy load rotation, leading to overheating and damage, resulting in rotor shaft string and deformation jamming;
4. Deformation of the rotor drive end shaft head due to meshing clearance or gear key connection failure of the drive coupling gear;
5. Abnormal damage caused by bearing quality reasons. The above faults of the air compressor are generally caused by human factors. In daily maintenance and repair work, as long as you carefully follow the operating and maintenance procedures, the above faults can be completely avoided.
In short, the suction and exhaust end journals of the screw compressor rotor are supported by bearings on the compressor body and exhaust bearing seat, respectively. If the coaxiality of the compressor body, exhaust bearing seat, and rotor does not meet the design requirements due to mechanical processing or assembly, it is easy to cause scratches or rotor jamming between rotors, between rotors and the body, and between rotors and other parts. The coaxiality between the shaft hole and the rotor compression chamber is generally required to be within 0.01-0.02mm.
The clearance between the parts in the compression chamber of a screw compressor is generally measured in threads or millimeters. The parts in the compression chamber are dynamically matched. If the designed clearance value is too small, combined with manufacturing errors, it is easy to cause the rotor to be scratched or stuck. The gap between the rotor and the body is generally about 0.1mm, and the gap between the exhaust end face of the rotor and the exhaust bearing seat is 0.05-0.1mm.
During the disassembly process of the compressor, due to the tight fit between the bearings and the rotor shaft, excessive disassembly force will cause deformation of the parts and reduce their coaxiality.
After assembling the compressor, it is necessary to check the overall coaxiality of the assembly parts. If the coaxiality exceeds the tolerance, it can also cause scratches between the parts or the rotor to be stuck.
