Roots blower is a volume rotary fan. The compressor keeps the two rotors engaged by the synchronous gear at the rotor shaft end. Each concave curved surface on the rotor forms a working volume with the inner wall of the cylinder. During the rotation of the rotor, the gas is taken away from the suction port. When the rotor moves to the exhaust port near which it is connected with the exhaust port, the pressure in the working volume suddenly rises due to the backflow of high pressure gas, and then the gas is transported to the exhaust channel. The two rotors do not contact each other, and they are sealed by a tightly controlled gap, so the discharged gas is not polluted by lubricating oil.
After the rotor system of Roots blower suffers from misalignment fault, a series of dynamic effects will be produced during the rotation process, which will be detrimental to the operation of the equipment, causing deflection of the coupling, wear of the bearing, steady oil film, deflection and deformation of the shaft, etc. The force on the rotor and the additional force on the bearing will lead to abnormal vibration of Roots blower and early damage of the bearing, which will do great harm. At present, we generally adopt the original method to deal with the misalignment fault of the fan. First, level the main shaft of Roots blower, and rotate the impeller to ensure that the levelness deviation of the main shaft of the blower at each point is within the range; Then find the alignment of the fan and motor coupling. Generally, use a dial indicator to detect the runout at four points to ensure that the runout at four points is within the technical range, so that the alignment is basically found.
1. The bearing clearance is too large or the ball has pitting corrosion, which is generally caused by insufficient lubrication or poor oil quality. This condition is likely to cause misalignment and vibration, and the bearing should be replaced as appropriate.
2. The bearing pedestal vibrates for a long time, causing deviation. As the vibration of large Roots blower is inevitable, it is easy to cause slight loosening of the fastening bolts of the base, which will lead to misalignment and vibration.
3. It is caused by the main motor itself. Large motors have high requirements for dynamic balance itself. Due to various reasons, the dynamic balance of the motor itself is damaged and the requirements are misaligned. Roots blower and motor are connected by coupling to transmit motion and torque. Misalignment is a common fault of Roots blower, 60% of which is related to misalignment. The misalignment fault of fan refers to the inclination or deviation degree between the axis lines of two rotors of fan and motor and the bearing center line.
After the rotor system of Roots blower suffers from misalignment fault, a series of dynamic effects will be produced during the rotation process, which will be detrimental to the operation of the equipment, causing deflection of the coupling, wear of the bearing, steady oil film, deflection and deformation of the shaft, etc. The force on the rotor and the additional force on the bearing will lead to abnormal vibration of Roots blower and early damage of the bearing, which will do great harm. At present, we generally adopt the original method to deal with the misalignment fault of the fan. First, level the main shaft of Roots blower, and rotate the impeller to ensure that the levelness deviation of the main shaft of the blower at each point is within the range; Then find the alignment of the fan and motor coupling. Generally, use a dial indicator to detect the runout at four points to ensure that the runout at four points is within the technical range, so that the alignment is basically found.
I believe that after reading the above contents, you should also understand the reason for the misalignment of Roots blower rotor. I hope it will be helpful to you.
Text label: Roots blower
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