The clearance between the blades (rotors) of a Roots blower is a key parameter to ensure its operation, avoid mechanical friction, and prevent gas leakage. The following are detailed gap standards and adjustment methods:
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**1、 Roots blower blade clearance standard**
**1. Three leaf Roots blower**
|* * Gap Type * * | * * Standard Range (mm) * * | * * Measuring Tool * *|
|--------------------|-------------------|-------------------|
|* * Inter rotor meshing clearance * * | 0.08~0.15 | feeler gauge or dial gauge|
|Radial clearance between rotor and casing * * | 0.10-0.25 | feeler gauge|
|* * Axial clearance between rotor end face and wall panel * * | 0.20-0.40 | Dial gauge|
**2. Two blade Roots blower**
|* * Gap Type * * | * * Standard Range (mm) * * | * * Remarks * *|
|--------------------|-------------------|-------------------|
|The meshing clearance between rotors is 0.10-0.20, slightly larger than that of the three bladed type|
|* * Radial clearance * * | 0.15~0.30 | Due to the thick and short blade shape, the clearance is slightly larger|
|Axial clearance * * | 0.25-0.50 ||
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**2、 Gap adjustment method**
**1. Mesh clearance adjustment (key step)**
-* * Tools * *: feeler gauge (0.02mm accuracy), gear phase adjustment tool.
-* * Steps * *:
1. Manually rotate the disc to ensure that the two rotors are in a 90 ° meshing position (one vertical and the other horizontal).
2. Use a feeler gauge to measure the gap between the rotor working surfaces (at least 3 points).
3. * * Adjust gear phase * *:
-Loosen the fixing bolts of the synchronous gear and fine tune the gear angle.
-For every 1 ° adjustment of the gear angle, the clearance changes by approximately 0.02-0.05mm.
4. After locking the bolt, retest to ensure that the entire rotation is unobstructed.
**2. Radial clearance adjustment**
-Method: Control the concentricity between the rotor and the casing by increasing or decreasing the thickness of the bearing seat gasket.
-* * Standard * *: The gap should be uniform (with a deviation of ≤ 0.05mm from top to bottom, left to right).
**3. Axial clearance adjustment**
-Method: Adjust the thrust bearing or end cap gasket to limit the axial movement of the rotor.
-Attention: Too small axial clearance can cause end face wear, while too large clearance can increase gas leakage.
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**3、 Gap correction under different working conditions**
|* * Working condition * * | * * Gap adjustment suggestion * * | * * Reason * *|
|-------------------|-------------------------------|--------------------------|
|High pressure (>0.5bar) | Upper limit of meshing clearance (0.15-0.20mm) | Prevent rotor collision caused by thermal expansion|
|High temperature (>80 ℃) * * | Radial clearance increases by 10-20 | Compensation material thermal deformation|
|* * Dusty gas * * | Increase all gaps appropriately (+0.05mm) | Avoid gaps that are too small after dust abrasion|
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**4、 The consequences of abnormal gaps**
|* * Problem * * | * * Possible Fault Phenomena * * | * * Solution * *|
|-------------------|-----------------------------|-------------------------|
|* * Clearance too small * * | Rotor friction, abnormal noise, temperature rise | Adjust gear phase or bearings again|
|* * Excessive gap * * | Decreased air volume and efficiency | Replace worn rotor or adjust gasket|
|Uneven gap | Localized wear and increased vibration | Correct rotor dynamic balance|
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**5、 Maintenance suggestions**
1. * * Regular inspection * *: Measure the gap every 2000 hours of operation or 6 months.
2. Lubrication and maintenance: Use high-temperature lithium grease to lubricate bearings and reduce clearance changes caused by wear.
3. * * Replacement standard * *: When the clearance exceeds the standard value of 50 (such as mesh clearance>0.25mm), the rotor needs to be replaced.
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**6、 Precautions**
1. * * Before adjustment, the machine must be shut down and powered off * * to ensure.
2. Use high-precision tools (such as a dial gauge) to reduce human error.
If abnormal vibration or noise occurs during operation, the machine should be stopped immediately to check the clearance.
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**Reminder: Different manufacturers and models of Roots blowers may have specific requirements, please refer to the equipment manual. For high-pressure or special material fans (such as stainless steel), it is recommended to have them adjusted by professionals.
