The main function of the axial positioning of Roots blower is that when the Roots blower is running, the shaft system will produce linear expansion and body expansion due to the rotor heating. The volume expansion reserve is ensured by radial processing, and the linear expansion reserve is determined by axial positioning. If the axial reserve is too large, the fan efficiency will become low; The axial reserve is too small, Roots drum Fan casing and bearing will be damaged due to heat.
Bearing pedestal end face wear There are two main reasons for bearing pedestal end face wear. One is that foreign matters enter the rotor and bearing pedestal end face, which is too small to be analyzed here. The other is that the axial clearance is not enough, which causes the contact wear between the rotor and the bearing end face when the rotor expands online. We know that the molecules of any substance are doing irregular thermal movement. Molecules have speed and kinetic energy. Microscopically, the pressure of gas is the impact of a large number of molecules on the container wall, and the temperature is the measurement of the average kinetic energy of the thermal movement of a large number of molecules.
The higher the temperature is, the greater the average kinetic energy of the thermal movement of the molecule, and the greater the speed of the molecule. We know that the greater the speed, the more violent the impact, that is, the greater the pressure of the gas. When Roots drum When the fan generates pressure, on the contrary, the gas will generate temperature. The temperature causes the rotor to stretch. If the clearance is not enough, it will cause friction between the rotor and the casing. The axial clearance is too small, which causes the end cover and the impeller end face to wear and generate heat at the same time. Through heat conduction, the bearing temperature will increase, thus damaging the bearing and the sealing ring. The fan efficiency will be reduced if the axial clearance is too large.
As Roots blower is a positive displacement fan, its wind pressure has something to do with the system, but has little to do with others. That is to say, it has a definite relationship with the characteristics of the outlet pipeline. The flow rate has a great relationship with the fan speed. However, if the axial clearance is adjusted too large, a gas channel will be formed at the impeller end face and the bearing seat end face. The gas channel will make the pressurized air return through it Roots drum The suction port of the fan makes the fan continuously do quantitative useless work Roots drum The air volume of the fan decreases and the efficiency decreases.
Roots blower vibrates. When the clearance is too small, the impeller end face rubs against the bearing seat end face. The unit will produce strong vibration due to friction between dynamic and static parts. Excessive vibration is easy to cause friction between the dynamic and static parts, which can lead to disastrous consequences. Friction occurs at the seal ring of the shaft, which will cause further increase of vibration caused by the thermal bending of the rotor, forming a vicious cycle and causing permanent bending of the rotor. Vibration and shaft bending will cause bearing damage
Routine maintenance of Roots blower rotor:
1. During the general inspection of Roots blower, clean the rotor and check whether there are cracks on the surface.
2. When we overhaul Roots blower, if rust and iron thorn are found on the rotor, we need to clean it and polish it.
3. Check the bending degree of the rotor. The bending degree of the rotor is less than 0.08mm under normal conditions, and the ovality of the journal is less than 0.01mm under normal conditions.
4. The size of the journal and the inner ring of the bearing should meet the requirements. If there is serious wear, it should be adjusted and maintained in time
5. The surface condition of the impeller shall be checked. The surface and shaft of the impeller shall be free from serious wear. If there is serious wear, the cause shall be found and treated.
6. If the shaft or impeller needs to be replaced due to defects, remove the impeller from the shaft, measure the assembly clearance between the shaft and impeller during assembly, and conduct dynamic balance correction for the reassembled rotor.
I believe that after reading the above, you should also have some understanding of how to adjust the axial positioning of Roots blower rotor. I hope it will be helpful to you.
Text label: Roots blower
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