The following is a maintenance guide for Roots blowers, covering common fault diagnosis, disassembly steps, key component maintenance, and precautions to help you systematically solve blower problems:
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**1、 Preparation before maintenance**
1. * * Measures**
-Power off and lock out (LOTO), confirm that the fan has stopped.
-Pressure relief: Open the exhaust valve to vent the residual gas in the pipeline.
2. * * Tool List**
-Basic tools: wrench, puller, feeler gauge, micrometer.
-Special tools: bearing heater, laser alignment instrument (coupling calibration).
3. * * Technical documentation**
-Refer to the fan manual to confirm the standard value of rotor clearance, bearing model, and other parameters.
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**2、 Common faults and repair steps**
**1. Insufficient air volume**
-Possible reasons:
-Filter blockage → Remove the filter element for cleaning or replacement.
-Belt slippage → Adjust tension (press down 5-10mm) or replace belt.
-Excessive rotor wear clearance → Use a feeler gauge to check the clearance (standard 0.2-0.4mm), and replace the rotor if it exceeds the tolerance.
**2. Abnormal vibration/noise**
-* * Troubleshooting steps * *:
1. * * Check the foundation bolts * *: Tighten loose bolts and check if the shock absorber pads are aging.
2. * * Bearing Inspection * *:
-Remove the bearing cover and manually rotate it to listen for any abnormal noise.
-If the clearance is too large (axial>0.1mm), it needs to be replaced (model such as SKF 6316).
3. * * Rotor dynamic balance * *:
-Remove the rotor and send it to a professional organization for dynamic balancing (residual unbalance ≤ 1g · cm).
**3. Oil temperature too high (>80 ℃)**
-* * Handling method * *:
-Oil Change: Drain the old oil and add ISO VG220 gear oil to the centerline of the oil window.
-* * Clean the cooler * *: Blow the heat sink with compressed air.
-Check gear meshing: The gear set needs to be replaced due to pitting corrosion on the tooth surface.
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**3、 Disassembly and maintenance of core components**
**1. Disassembly of rotor assembly**
1. Dismantle the import and export pipelines and couplings.
2. Loosen the bearing seat bolts and use a puller to pull out the bearing (heated to 80 ℃ for easier disassembly).
3. Lift out the rotor and check the wear of the impeller (if the wear is greater than 2mm, it needs to be repaired or replaced by welding).
**2. Seal replacement**
-Maze seal:
-Measure the clearance between the sealing ring and the shaft (standard 0.1-0.2mm), and replace it if it exceeds the tolerance.
-* * Mechanical seal * *:
-Check the wear of the dynamic/static rings and apply silicone grease (such as EG-151) when replacing them.
**3. Coupling calibration**
-Use a laser centering device to adjust the coaxiality of the motor and fan (deviation ≤ 0.05mm).
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**4、 Post repair testing**
1. * * No load trial operation * *:
-Tap to start and confirm the correct direction of rotation (indicated by the arrow).
-Run for 30 minutes, monitor current, vibration (≤ 4.5mm/s), and temperature rise (bearing<70 ℃).
2. * * Load Test * *:
-Gradually close the exhaust valve to the working pressure and check for overcurrent.
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**5、 Key precautions**
-* * Prohibited operation * *:
-Disassemble under pressure and start directly without turning.
-* * Replacement parts standard * *:
-It is recommended to use original or SKF/NSK brand bearings, as poor quality bearings can easily lead to secondary failures.
-* * Maintenance cycle * *:
|* * Component * * | * * Maintenance cycle * *|
|---------------|-------------------|
|Lubricating oil | First 500h, then 3000h|
|Belt | Check and replace every 6 months|
|Bearing | 30000 to 50000 hours of service life|
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**6、 Professional repair vs self repair**
-* * Suggested self repair * *: filter replacement, belt adjustment, simple dust cleaning.
-* * Requires professional personnel * *:
-Rotor dynamic balance correction, gearbox overhaul, high-pressure model seal replacement.
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**7、 Maintenance cost reference**
|* * Maintenance project * * | * * Cost range (yuan) * *|
|------------------|-------------------|
|Replace bearings | 800-2000/set|
|Rotor repair | 3000-10000|
|Mechanical seal replacement | 1500-5000|
|Whole machine overhaul | 10000-30000 yuan (55kW model)|
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**Tip * *: If encountering complex faults (such as impeller fracture, shell deformation), it is recommended to contact the manufacturer or professional repair service provider to avoid misoperation and further losses.
